CSR-T Volume 6 #5, July-August 1995

COMMUNICATIONS STANDARDS REVIEW TELECOMMUNICATIONS

Volume 6, Number 5 July–August 1995

IN THIS ISSUE

The following reports of recent standards meetings represent the view of the reporter and are not official, authorized minutes of the meetings.

TR-30, Data Transmission Systems and Equipment, May 15 – 19, 1995, Mississauga, Ontario, Canada...... 2 TR-30.1 Modems...... 2 TR-30.2 Data Transmission...... 3 TR-30.3 Data Communication Equipment Evaluation and Network Interfaces...... 4 TR-30.4, DTE-DCE Protocols...... 6 TR-30 Partial Meeting Roster, May 15 – 19, 1995, Mississauga, Ontario, Canada...... 8 European Telecommunications Standards Institute (ETSI) Terminal Equipment Plenary Meeting,...... 9 June 5 - 9, 1995, Perros-Guirec, FRANCE...... 9 ETSI Meeting Roster, June 5 – 9, 1995, Perros-Guirec, France...... 18 SG 15 Experts Group Meeting on G.DSVD, June 17, 1995, Montreal, Canada...... 19 G.dsvd Experts Meeting Roster, June 17, 1995, Montreal Canada...... 20 Very Low Bitrate Visual Telephony Rapporteur’s Meeting (Question 2/15), June 20 – 23, 1995, Newton, Ma...... 22 Video Coder (H.263)...... 22 Speech Coder (G.723)...... 24 Multiplex (H.223)...... 26 Communication Control (H.245)...... 26 System (H.324)...... 28 Mobile...... 30 H.26P/L...... 32 H.324 Testing...... 32 DTE/DCE Interface...... 32 H.324 Non-Conversational Services...... 33 LBC Rapporteur’s Meeting Roster, June 20 – 23, Newton, MA...... 34 TR-30.1/TR-30.4 Joint DTE-SAVD DCE Ad Hoc Meeting, July 6 – 7, 1995, Irvine, CA...... 35 TR-30.1/TR-30.4 Joint Ad Hoc Meeting Roster, July 6 – 7, 1995, Irvine, CA...... 38 TR-30, Data Transmission Systems and Equipment, July 10 – 14, 1995, Irvine, CA...... 39 TR-30.1 Modems...... 39 TR-30.2 Data Transmission...... 42 TR-30.3 Data Communication Equipment Evaluation and Network Interfaces...... 43 TR-30.4, DTE-DCE Protocols...... 45 TR-30 Meeting Roster, July 10 – 14, 1995, Irvine CA...... 48 Acronym Glossary...... 49 1995 Meeting Schedules as of August 9. 1995...... 51

July-August 1995 Vol. 6.5 Copyright © CSR 1995 1 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS REPORT OF TR-30, DATA TRANSMISSION SYSTEMS AND EQUIPMENT MAY 15 – 19, 1995, MISSISSAUGA, ONTARIO, CANADA TR-30.1 MODEMS

LIAISONS

TR-30.1/95-05-069 (L. Brown, V.8bis Rapporteur) is a report of the April 5-7, 1995, V.8bis Rapporteur meeting. The Chair, L. Brown (Motorola ISG), touched on each of the decisions made at the meeting (see CSR-T vol. 6.3, p. 36). He also highlighted the 18 agreements reached, as listed on pages 6 and 7 of the document. TR-30.1/95-05-070 (L. Brown, V.8bis Rapporteur) is a report of the April 19-27, 1995, V.8bis meetings held at the ITU-T SG 14 meeting in Geneva. The Chair highlighted Item 7 which lists the outstanding issues resolved at the meeting. TR-30.1/95-05-074 is an overview of the activities of SG 14 at the recent April meeting in Geneva. D. Brandt (AT&T), the Chair of ITU-T Working Party 1/14, briefly introduced this document. It highlights the Working Party’s accomplishments and future plans. TR-30.1/95-05-072 (D. Rife, Hayes) proposes the addition of +T test commands to PN-2989 (Extensions to Asynchronous Serial Automatic Dialing and Control). Since it had been previously addressed in TR-30.4 (see report below), the document was provided for information only. V.34 TR-30.1/95-05-073 (A. Sadri, IBM) proposes that a new Annex be developed for Recommendation V.34. New, faster training, equalization, re-training and use of data interleaving techniques could be developed to counter the problems caused by channel fading in analog cellular networks. There was considerable discussion regarding this proposal. It was clear that the proposal envisions the use of specific equalizer techniques in the receiver, and it was decided to start a project to investigate this possibility. Contributions to this work are encouraged. It was not clear as to whether this would result in a U.S. Standard or be destined for input to the ITU. TR-30.1/95-05-071 (IMTC [International Multimedia Teleconferencing Consortium], presented by J. Decuir, Microsoft) proposes that a concerted effort be made to develop a mechanism to switch directly between different services and applications (e.g., V.34 fax, V.dsvd, H.324 Video phone) that use a common physical layer without discontinuing that carrier. It examines three different ways to accomplish this: 1. Drop back to voice 2. Modify V.8 and/or V.8bis to transfer their respective commands at V.34 speeds rather than dropping to V.21 3. Modify V.dsvd and H.324 to define specific methods for affecting transitions between the two applications. During discussion, it was clear that no one favored going back to voice. It was suggested that the V.dsvd control channel could be used to negotiate these mode switches. Another suggestion was that the V.34 secondary channel might be a good candidate for carrying this information. It was also suggested that H.245 could be used to negotiate this switch from the video telephony mode. It was finally decided to have an ad hoc group more clearly define the pros and cons associated with each proposal. The ad hoc group met, and TR-30.1/95-05-076 (J. Decuir, ad hoc Chair) is the output from their meeting. The group concluded that modification of H.324 and H.245 would be the best approach. Specific modifications to individual paragraphs of these two Recommendations were identified. It was proposed that since T1A1 would not meet again before the next meeting of the SG 15 LBC group, a multi-company contribution should be drafted for input to that meeting. C. Hansen of Intel offered to present this to the June LBC meeting in Boston (see report in this issue of CSR-T). V.8BIS TR-30.1/95-05-068 (L. Brown, V.8bis Rapporteur) is the latest draft of Recommendation V.8bis. All of the changes that were agreed to at the SG meeting are incorporated in this draft. TR-30.1/95-05-077 (B. O’Mahony, Intel) contains a revision to the state diagrams for V.8bis Figures 8 and 9 in TR-30.1/95-05-068 above. The revisions align the diagrams with the allowable transactions listed in Table 13. At this point, the TR-30.1 meeting was adjourned and the Chair, acting as V.8bis Rapporteur, asked for assistance from TR-30.1 in performing his job of producing clean text for the TSB (Telecommunication Systems Bulletin).

After obtaining the group’s concurrence, he led a point by point analysis of the draft to determine if there were still any errors in the text. Table 1 is a list of the some of the discussion points. Dick Brandt, dB Consulting

Subject Unclear Agreement Use of 2nd info field in frame What can be in the 2nd field Change and/or to and in 7.2.7 Supplemental frames What goes in first field of a Specify empty frame supplement frame CL-MS signal in TABLE 13 How CL-MS signal is constructed Change the notation in Table 13 to show CL, MS indicating the signals are sent sequentially ESr preceding MS, CL and CLR When this occurs Text added to 9.4 to clarify this is only at call establishment Transmit ES What delay is needed prior to 400 ms will be added sending ACK and NAK There might be a conflict between No change Note 1 under Table 13 and paragraph 4 under 9.6 Maximum number of octets in the Show 64-p Change 2nd paragraph under 8.2.3 to 64 NS field octets Length of T.35 Country and Presently this is only limited by a No change Provider codes note Table 1. V.8 bis Points of Discussion in TR-30.1

TR-30.2 DATA TRANSMISSION

ITU-T S TUDY GROUP 14 REPORT

A verbal overview report of the activities which had taken place at the April 19-27, 1995, meeting of ITU-T SG 14 was given. TR-30.2/95-05-013 (F. Lucas, Chair, General DataComm), provides a detailed report of Working Party 1 Question 6 work that was specifically related to work in TR-30.2. One area of interest, which was also discussed at the March 31 meeting of TR-30.2, was the recommendation from ISO/IEC JTC1/SC 6/WG 3 to delete the 200-series of interchange circuits in Recommendation V.24. This issue was also considered under Question 7/14. TR-30.2/95-05-016 (L. Brown, V.25ter Rapporteur) is a report of the April Q7/14 meeting and provides a report of this work. No decisions had been made at the SG14 meeting regarding this issue; however, TR-30.2 agreed to initiate a related work item. TIA standard EIA-366-A, “Interface between Data Terminal Equipment and Automatic Calling Equipment for Data Communication,” is long overdue for review. It was agreed that in light of the proposed deletion of the equivalent international recommendations in this area, a proposal and ballot to withdraw EIA-366-A be initiated. The continued use of EIA-366-A in newly developed DCEs (Data Circuit Terminating Equipment) and DTEs (Data Terminal Equipment) has been supplanted with serial interfaces making use of the AT Command set. It was also felt that by going to ANSI ballot to withdraw EIA-366-A, feedback could be obtained as to the stance of U.S. industry regarding the associated ITU-T work. It was announced that Working Party 1/14 will have a meeting in Munich, Germany, during October 1995. The one item of consideration for Question 6 will be revisions to V.24. A U.S. position will be needed regarding the 200- series circuits for that meeting. ISO/IEC B ALLOTS

Two recommendations were made regarding U.S. positions on ballots in ISO/IEC. TR-30.2/95-03-010 is ISO/IEC CD 8481:1995. This revised standard, “Information Technology - Telecommunications and Information Ex- change between Systems - DTE to DTE Direct Connections,” was provided to TR-30.2 at the March meeting. At this meeting, it was recommended that the U.S. vote yes. TR-30.2/95-03-011 is the latest revision of ISO/IEC CD 2110, “Data Communication - 25-pole DTE/DCE Interface Connector and Contact Number Assignments.” It was also

July-August 1995 Vol. 6.5 Copyright © CSR 1995 3 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS provided to TR-30.2 at the March meeting. It was decided by TR-30.2 to recommend a yes ballot; however, a number of editorial corrections were recommended to be included with the ballot. These are contained in TR-30.2/95-05- 015 and included changing the maximum data rate to 28.8 kbit/s for V.34 DCEs and eliminating confusion in Table 1 of the document. DTE/DCE INTERFACE FOR DIGITAL CELLULAR (PN-3138)

Some progress was made on PN-3138. TR-30.2 had been awaiting a recommendation from TR-45.3 as to their acceptance of a new connector which was suggested in December 1994. Feedback from the TR-45.3 liaison, A. Sacuta (Ericsson), indicates growing support for this connector, including the RF portion. TR-45.3 may suggest that the connector contain 12 pins making it sufficient for their use. It is hoped that a formal request from TR-45.3 will be received at the July meeting of TR-30.2. If this occurs, it may be possible to ballot a draft standard out of the July meeting. VERY HIGH SPEED INTERFACE, ELECTRICAL CHARACTERISTICS (SP-3357)

The Chair reported that the ANSI industry ballot on SP-3357 (Very High Speed Interface, Electrical Characteristics) closed on May 16, 1995. One ballot had comments, but all ballots returned were yes ballots. The comments were from Hayes Microcomputer and are contained in TR-30.2/95-05-014. The comments were editorial in nature, and some were easily handled by TR-30.2. The balance was referred to the ad hoc committee on electrical characteristics for resolution. It appears that, with the editorial changes already agreed upon and those that will come from the ad hoc committee, this new standard should be sent for publication in July 1995. When published, it will be TIA/EIA-644, “Electrical Characteristics of Low Voltage Differential Signaling (LVDS) Interface Circuits.” MEDIUM SPEED DTE/DCE INTERFACE (PN-3416)

No additional progress was made on completing this new standard. The only change made was to rename the draft to “DTE/DCE Interface for Data Rates up to 116 kbit/s.” The remaining issue to be completed before industry ballot is finalizing a recommendation for connection of circuit and frame commons. Hopefully, this will be completed at the July 1995 meeting so that an ANSI industry ballot can be approved at the same meeting. Fred Lucas

TR-30.3 DATA COMMUNICATION EQUIPMENT EVALUATION AND NETWORK INTERFACES J. Douglass (Motorola, TR-30.3 chair) recommended that the name of TR-30.3 be changed to “Data Communications Equipment Evaluation and Network Interfaces” because the scope TR-30.3’s work has changed. He submitted the request to TR-30 in TR-30.3/95-05-051. FCC LIAISON

TR-30.3/95-05-035 is the FCC BillBoard for April 1995; TR-30.3/95-05-038 is the FCC BillBoard for May 1995. They were distributed for information only. TR-30.4 LIAISON

TR-30.3/95-05-044 (D. Rife, Hayes) proposes +T test commands for inclusion in PN-2989 (Extensions to Asynchronous Serial Automatic Dialing and Control). It was distributed for information only. PN-3459, PSTN TRANSMISSION MODEL AND TEST PROCEDURES FOR EVALUATION OF 2 WIRE HIGH SPEED DUPLEX MODEMS

PN-3459 makes TSB-37-A (Telephone Network Transmission Model for Evaluating Modem Performance) into an ANSI Standard. TR-30.3/95-05-046 (S. Satchell, Satchell Evaluations) proposes changes to Section 4.5 of PN-3459 (PSTN Transmission Model and Test Procedures for Evaluation of 2 Wire High Speed Duplex Modems). The changes address out-of-band responses by the simulator, digital link requirements, and test points. TR-30.3/95-05-048 (S. Satchell, Satchell Evaluations) is Draft 4 of PN-3459, dated May 14, 1995. It includes Editor’s notes. TR-30.3/95-05-050 (J. Hoang, Rockwell) is model deficiencies of TSB-37-A.

R. Perez (Bellcore) stated that he had experienced problems in the field with the V.34 modem operating on short loops. He has been resolving the problems by adding a pad to provide more loop loss and by changing the network balancing impedance. After considerable discussion, TR-30.3 decided the following: • Tests should be added that simulate stressful line conditions, such as multiple stages of robbed bit signaling, errors in the T1 digital stream, T1 timing slips, gain hits, and defective/out of spec lines. • V.56bis and TSB-37-A should be compared and a list of differences compiled. V.56bis should be the only recommendation for the network model if the two documents are closely enough aligned. • J. Douglass (Motorola), J. Moran (Motorola), L. Brown (Motorola), and R. Perez (Bellcore) agreed to get together on a conference call to discuss these issues. PN-3509, TEST PROCEDURE FOR EVALUATION OF 2 WIRE 4-KILOHERTZ VOICEBAND DUPLEX MODEMS

PN-3509 makes TSB-38 (Test Procedures for Evaluating 2 wire 4 Kilohertz Voiceband Duplex Modems) into an ANSI Standard. TR-30.3/95-05-045 (D. Rife, Hayes) proposes an alternative to reporting zero throughput when an invalid test condition occurs in the modem test procedures.

TR-30.3/95-05-047 (S. Satchell, Satchell Evaluations) contains Draft 2 of PN-3509, dated May 14, 1995. It includes Editor’s notes. After discussing these documents, TR-30.3 agreed to send out PN-3509, Draft 2, for TIA/EIA/ANSI letter ballot. S. Satchell, Editor, will incorporate a number of agreed changes before the document is sent to TIA. These change are listed in TR-30.3/95-05-052, SP-3509 Letter Ballot Request and Instructions to the Editor. PN-3251, CELLULAR NETWORK TRANSMISSION MODEL FOR EVALUATING MODEM PERFORMANCE PN-3507, TEST PROCEDURE FOR EVALUATION OF CELLULAR MODEMS PERFORMANCE

TR-30.3/95-05-049 is a report of the ad hoc group meeting held on May 17, 1995. The output of the ad hoc meeting was a first draft of PN-3251 (Cellular Network Transmission Model for Evaluating Modem Performance) that included a first cut at a stress-based RF Simulator Impairment Combination Table. TR-30.3/95-05-036 (M. Gauer, Air Communications) is a paper discussing the need to test a broad range of configurations including different manufacturers modems at each end. TR-30.3/95-05-039 (C.N. Firth, Acting Rapporteur on Cellular Modems) contains the SG 17 Revised Test Suite for Cellular Modems, COM XVII-23-E, April 1992. TR-30.3/95-05-040 (A. Sacuta, Ericsson) contains a block diagram and tutorial for the cellular analog traffic channel. This is an excellent series of tutorials from Cellular TechNotes describing in technical detail the operation of a cellular system in the areas that affect circuit mode data transmission. TR-30.3/95-05-041 (A.S. Sadri, IBM) is a proposal for a cellular PSTN modem based upon Recommendation V.34. It notes two major problems associated with signaling at high data rates over analog cellular, low SNR of the FM radio portion (typically 10-20 dB) and the restricted bandwidth of the telephone portion (large ISI). The paper proposes the following enhancements to V.34 to improve operation over analog cellular: • A faster start-up to allow faster convergence for the equalizer and echo canceller • A faster equalization. • A suitable size interleaving prior to modulation. • A faster retraining circuit to allow fast recovery during severe fading and carrier loss. • A periodic fast training to track the fading of the channel. TR-30.3/95-05-042 (T. Myers, Ameritech Cellular Services) illustrates the Ameritech cellular modem test bed. It also includes screen captures of the user software interface. It is an example of a test setup incorporating a dual terminal emulator for stimulus response measurements of modems under test (MUT). TR-30.3/95-05-043 (A. Sacuta, Ericsson) contains selected sections from IS-136 (800 MHz Cellular System, TDMA Radio Interface, Dual Mode Mobile Station Compatibility Standard) and IS-137 (800 MHz TDMA Cellular Radio Interface, Minimum Performance Standards for Mobile Stations).

After discussing the above documents, TR-30.3 decided the following: • The cellular system terminology used should match the terminology that is used by the industry. A. Sacuta (Ericsson) will submit a list of terms that are used by TR-45 for cellular systems. • Tests should be run using the RF Simulator Impairment Combination Table that was drafted at the ad hoc meeting, to see if the selected values are realistic. T. Myers (Ameritech) agreed to run some tests over the impairment combinations using several different cellular modems. Jack Douglass

TR-30.4, DTE-DCE PROTOCOLS

LIAISON REPORTS

D. Brandt (AT&T) presented TR-30.4/95-05-048, his report of the Study Group 14 April meeting in Geneva. At that meeting, previously determined Recommendations V.8bis, V.12 (V.hssi), V.25ter, V.56bis and V.130 (ISDN Terminal Adaptor) were given final approval. However, three administrations invoked the six week rule on V.8bis. Subsequently, at least two of these administrations, the UK and the U.S. voted No on V.8bis, which will now have to wait until March 1996 to seek final approval again. Also, draft Recommendations V.asvd (V.61), V.gmux (V.62) and revision of V.120 (to include V.42bis data compression) were determined for Resolution 1 treatment and may be approved at the March 1996 meeting of Study Group 14. There will be a DSVD (Digital Simultaneous Voice Data) Rapporteur meeting in Portland, Oregon, August 7-12 which will include V.8bis discussions, and a SG 14 Working Party 1 meeting in Munich, October 9-13, where outstanding SAVD (Simultaneous or Alternating Voice Data) Recommendations should be determined for Resolution 1 treatment. TR-30.4/95-05-040 (L. Brown, Motorola ISG) is the report of the Q7/14 meeting held during the SG 14 meeting in April. At that meeting: • V.25ter received final approval. • The V.25ter Supplement and the registration authority procedure for updating it were approved by the Study Group. • A proposed new Annex A/V.25ter for V.8 DCE control was presented; it was agreed to accept the proposal as baseline text, with the goal of Resolution 1 determination from the October Working Party 1 meeting. • A proposed draft Recommendation V.ib for in-band DCE control (TIA-617) was presented; it was agreed that the proposal would be used as baseline text, unless there is no further justification of a need for such a Recommendation. • An overview of IS-101 (voice DCE) was presented. • The need for the V.25 parallel automatic calling procedure was questioned. There is a desire to eliminate the 200- series interchange circuits. In the U.S., this is found in RS-366. F. Lucas, TR-30.2 Chair, agreed to take this up in his committee. C. Garthwaite (Microsoft), PN-3131 Editor, presented a liaison from TR-29.2 transferring all future work on PN-3131 (Asynchronous Voice DCE Control, revision of PN-2986) to TR-30.4 (TR-30.4/95-05-41). It was decided to transfer this work to TR-30.4 since TR-30.4 and ITU-T SG 14 are developing a DTE-DCE interface protocol for SAVD which is closely related to this work. The TR-30.4 Chair will send a letter to the TIA to inform them of the transfer. PN-2989 EXTENSIONS TO SERIAL ASYNCHRONOUS DIALING AND CONTROL

TR-30.4/95-05-037 (D. Rife Hayes, Microcomputer Products) proposes +T modem test commands based on V.58 and the subsequent SNMP (Simple Network Management Protocol) modem MIB (Management Information Base). The proposal was discussed by TR-30.4, and modifications were proposed. D. Rife then produced TR-30.4/95-05- 037R1 which includes the following changes: • Removal of the +TSGT (Send Guard Tone) command for now. D. Rife agreed to think about producing a separate paper expanding the +TSGT command to the more general case of control over startup signals. • Removal of +TTIM (Test Timer) and references to it, since it was decided that there is no need for it. • Specification that the +TTER (Test Error Rate) command shall run for the number of blocks specified. The command should also specify that type 0 (stop test) does not clear the results of a previous test. • Making all “implementations” optional. It was agreed to forward this to TR-30.1 and TR-30.3 for comment. TR-30.1 needs to review the loopback test commands as they pertain to V.34 “loopback” tests, particularly for asymmetrical data rates in V.34, which will require a new solution and modifications to V.54.

During the discussion on PN-2989, it was proposed to include the material from TR-30.4/95-05-37 as a new Section 6.7 to V.25ter. It was agreed instead that the proposed new Annex A (from ITU-T SG 8) should be included in Section 6.3, Call Control. TR-30.4/95-05-044 , Extensions to V.25ter for V.8 DCE Control (J. Decuir, Microsoft) was discussed and modifications were proposed. J. Decuir then produced TR-30.4/95-05-044R1. It was suggested that this proposal be checked against Recommendation V.8 to make sure that there are no inconsistencies or potential problems. For example, what should a V.8-capable DCE do if the DTE tries to command it to transmit a message that is in violation of the V.8 specification? It was also suggested that the +A lead-in should be used instead of the +M lead-in. It was agreed that participants would take the proposal home for review and consideration at a future meeting with the goal of arriving at a U.S. position for the October SG 14 Working Party 1 meeting. It was pointed out that TR-30.4 needs to start work on an ANSI standard to replace IS-131 (Extensions to Serial Asynchronous Automatic Dialing and Control). PN-3319 VOICE/DATA MULTIPLEXING THE DCES - DTE-DCE I NTERFACE OPERATIONS

B. O’Mahony (Intel) presented the following three papers: • TR-30.4/95-05-038 (N. Kenyon, BT Labs), a liaison from SG 15 discussing requirements for the “dataport” for videophones. • TR-30.4/95-05-047 (LBC-95-110) (N. Kenyon, Q3/15 Rapporteur) contains technical proposals addressing some of the requirements. • TR-30.4/95-05-039 (T. Geary, DTE/DCE Ad Hoc Chair), is a liaison from the SG 15 Ad Hoc committee on DTE-DCE interfaces for multimedia terminals. This contribution suggests different implementations where the audio and video input and output partitioning resides in different entities (either DTE or DCE). TR-30.4/95-05-050 (B. O’Mahony, Intel) is a revised reference SAVD modem block diagram showing all of the functional units, inputs, and outputs in an SAVD modem and how they can be interconnected. TR-30.4/95-05-049, a primer on the T.120 standard developed by DataBeam, was provided by J. Decuir (Microsoft) for information. TR-30.4 discussed various types of interface protocols that could be used for this application. These included one based on asynchronous HDLC (High level Data Link Control) byte stuffing from ISO-3309, Hayes AutoSync, and one based on a Fax Class 1 type protocol. It was agreed that an Ad Hoc committee meeting would be required to further this work. It is scheduled to take place on July 6-7 in Irvine, California, just prior to the July TR-30 meeting. Members of TR-30.1 and T1A1.5 are invited. (See report, this issue of CSR-T.) An Email reflector has been set up to help progress this work. The address is “dtedce@nb. rockwell.com”. To subscribe, send an Email request to [email protected]. PN-3131 ASYNCHRONOUS VOICE DCE CONTROL

C. Garthwaite (Editor, Microsoft) presented TR-30.4/95-05-041 (the liaison from TR-29.2) along with its attachments (the latest draft of PN-3131 [revision of IS-101, Asynchronous Voice DCE Control] and a list of open issues). It is important to TR-29.2 that backward compatibility with IS-101 implementations be maintained in any revisions to the standard. One of the outstanding issues discussed was that TR-29.2 could not decide on the optional vs. mandatory nature of the commands. During discussion of the draft, it was agreed that Caller ID commands are not restricted to voice and should be removed from IS-101 and put into V.25ter. It was agreed that the goal is to have a common protocol for IS-101 and SAVD (full duplex, but maintaining the half duplex protocol of IS-101 for backward compatibility). It was also agreed that the highest priority should be to develop a Recommendation, and then possibly an ANSI standard. It was recognized that, depending on the progress with the Recommendation, it may be necessary to reaffirm IS-101 (due by September). PN-3131 will be discussed further at the Ad Hoc meeting on DTE-DCE interface issues on July 6-7 in Irvine, California. PN-3147 CONVERSION OF CCITT V SERIES OSI INFORMATION MODEL TO SNMP MIB

D. Rife (acting Editor) briefly presented TR-30.4/95-05-046, the latest draft of the SNMP modem MIB. He reported that the MIB does compile. This is the version that will be sent out for default ballot from this meeting.

PN-3499 WIRELESS MODEM CONTROL

TR-30.4 agreed to develop an ANSI/TIA standard based on PCCA (Portable Computer Communications Association) STD-101 and the first two Annexes. TR-30.4/95-05-045 (J. Decuir, Editor) is a first rough draft of PN-3499 with revision marks indicating proposed changes to STD-101. PCCA will review this draft at their June meeting. The plan is to send the proposed standard out for ANSI ballot from the July meeting of TR-30.4. TR-30, TR-45.3.2, TR- 45.5.1, and the PCCA will be included on the ballot distribution. V.25TER

TR-30.4/95-05-042 is the clean draft of Recommendation V.25ter, and TR-30.4/95-05-043 the Supplement to V.25ter. TR-30.4 members were asked to review and comment with editorial corrections by the end of the meeting. It will then be sent to the ITU-T SG 14 Secretariat for processing. L. Brown noted that Q4/14 has requested a modem reset capability in V.58 and that this should also be considered for inclusion in V.25ter. Les Brown, Motorola Codex

TR-30 PARTIAL MEETING ROSTER, MAY 15 – 19, 1995, MISSISSAUGA , ONTARIO, CANADA Dick Brandt, dB Consulting Chair, TR-30 Les Brown, Motorola Codex Chair, TR-30.1 Fred Lucas, General Datacomm Chair, TR-30.2 Jack Douglass, UDS-Motorola Chair, TR-30.3 Jay Bain, UDS-Motorola Chair, TR-30.4 Host: Motorola Codex Ameritech Ted Myers Microsoft Charlie Garthwaite AMP, Inc. George Lawrence Microsoft Joe Decuir AT&T Dick Brandt Motorola ISG Jack Douglass AT&T Fred Burg Motorola ISG Jerry Viviano AT&T Larry Smith Motorola ISG Les Brown AT&T Paradyne William Girton Motorola ISG Vedat Eyuboglu AT&T R.K. Smith National Semiconductor John Goldie Bell Mobility Phil Schultz Penril Datability Networks Dick Stuart Bellcore Ricardo Perez Primary Access John Rosenlof Compaq Computers Jess Oswalt Primary Access Richard Williams Consultronics Robert Fitts Radish Comm. Ann Heinke Digital Equip. Corp Remi Lisee Rockwell Glen Griffith Ericsson Al Sacuta Rockwell Joe Hoang General DataComm Fred Lucas Rockwell My Nguyen General DataComm Yuri Goldstein Satchell Evaluations Stephen Satchell Hayes Dave Rife TAS Michael Pellegrini Henderson Coms. Labs Warren Henderson Telebit Systems Ken Jones IBM Ali Sadri USRobotics Andy Norrell Intel Barry OMahony USRobotics Vladamir Prizhsky Intel Chris Hansen Verifone Jackson Ma Megahertz Wayne Park

8 Vol. 6.5 Copyright © CSR 1995 July-August 1995 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS REPORT OF EUROPEAN TELECOMMUNICATIONS STANDARDS INSTITUTE (ETSI) TERMINAL EQUIPMENT PLENARY MEETING JUNE 5 - 9, 1995, PERROS-GUIREC, FRANCE Editor’s note: This is the first report of ETSI work in CSR-T. We plan to continue reporting on ETSI Technical Committee (TC) Terminal Equipment (TE) meetings in the future. The development of an European Telecommunications Standard (ETS) is carried out in an ETSI Technical Committee (TC). Once the draft is approved in the TC, it is relayed to the ETSI Secretariat for Public Enquiry and then National Vote. A short discussion of the initiation of the ETSI standards process in ETSI-0695-TD-23 (page 1) may also be helpful to the reader. G. N. Lawrence (GPT, UK), ETSI TC TE Chair, opened the 14th Plenary meeting of ETSI TE. Permanent document TE(94)-214, the report of the TE 13th Plenary Meeting held in Nuremberg, was approved without comment. ETSI- 0695-TD-9 is a list of documents scheduled for approval at this meeting. The following STCs (sub technical committees) are included in this report of the TE committee: • TE1 Telematics: Videotex • TE2 Telematics: Facsimile, Document Handling and Transfer • TE3 Message Handling System • TE4 Audiovisual and Voice Terminals • TE5 General Terminal Access • TE6 Directory Systems • TE9 Card Terminals • TE10 Multimedia Planning and Coordination

ETSI-0695-TD-62 (G. N. Lawrence, Chair) is the status of TCR-TRs (Technical Committee Report-Technical Reports). It highlights the status of the different TCR-TR documents: • ETSI-0695-TD-29© is the Draft TCR-TR 035, “Security Algorithms Group of Experts (SAGE); Rules for the management of the Baras (Baseline Algorithm Recommended for use in Audiovisual Systems) algorithm.” • ETSI-0695-TD-30© is page 7 (Scope and UPT procedures) of Draft TCR-TR 036, “Universal Personal Telecommunications (UPT); Phase 2; User procedures and user states.” • ETSI-0695-TD-55© (ETSI TC-NA/Security Techniques Advisory Group [STAG]) is Draft TCR-TR 038, “A guide to the ETSI Security Standards Policy.” • ETSI-0695-TD-56© is Draft TCR-TR 041, “Business Telecommunications; Corporate Telecommunication Networks (CTN) Project Plan (DTR/Business Telecommunication Committee [BTC]-00008).” ETSI-0695-TD- 80 (TE4 Chair) states that Draft TCR-TR 041, dealing with Channel Aggregation, should reference TE4 work and standards. • ETSI-0695-TD-57© is Draft TCR-TR 040, “Universal Personal Telecommunication (UPT) Requirements on Information Flows and Protocols; UPT Phase 1.” • ETSI-0695-TD-58© is Draft TCR-TR 039, “Network Aspects (NA); ETSI wide work plan for IN/B-ISDN integration.” Permanent document TE(95)-74 and ETSI-0695-TD-5 provide the details of the meetings that the TE Chair attended since the last TE plenary. The Commission of the European Communities is looking at ways to reduce the time to publish CTRs (Common Technical Regulations). One way used for the GSM Phase II CTR was to run the technical public inquiry and the GATT (General Agreement on Trade and Tariffs) evaluation in parallel. While this procedure saves two months, it was a special arrangement just for GSM Phase II. G.N. Lawrence, the TE Chair, was re-elected for a period of two years by the Technical Assembly. ETSI-0695-TD-63 is the status update of documents approved by TC TE. It gives the status of the different TE STC (Sub Technical Committee) documents. Each of the STC Chairs were asked update the contents of ETSI- 0695-TD-63 by end of the meeting.

LIAISONS WITHIN ETSI

The High Level Task Force (HLTF) was set up by the ETSI General Assembly (GA) to look at ways to improve the working efficiency of ETSI. Some of the recommendations are far reaching and could go as far as affecting the existence of some of the ETSI Technical Committees. Permanent document TE(95)-59 and ETSI-0695-TD-52 provide the objectives of HLTF and extracts of its recommendations. Among those recommendations, the HLTF recommends two types of working groups: a Technical Competence Center equivalent to the present STC, and a semi- autonomous group that acts as project management on topics such as B-ISDN and Network Management. The HLTF also considers lower ETSI membership fees and a fee to participate in each meeting. Finally, the HLTF states that what customers of standards are actually looking for is interoperability of products and not so much conformance of products. Once the recommendations are accepted by GA, the HLTF would spend about six months explaining the changes and the reasons for changes; then it would move quite fast into the actual implementation of those changes. The findings of SRC6 (Strategic Review Committee No. 6) on European Information Infrastructure will first go to TA (Technical Assembly, the highest authority in ETSI on technical issues) and then will come to TE for action. The TE Chair is waiting for endorsement of SRC6 Recommendations by TA before he passes them to TE members. Under TC NA (Network Aspects), NA7 STC (Universal Personal Telecommunications) is closing. It will transferr its remaining activities to TE4 STC (Voice Terminals) and TE9 STC (Card Terminal) as defined in a liaison statement (ETSI-0695-TD-54) from TC NA to TC TE. ETSI-0695-TD-85 (G. Raimann, Landis and Gyr, Austria, and T. Ulseth, Telenor AS, Norway) accepts the transfer of the work items from NA TC to TC-TE TE4 on Universal Personal Telecommunications. ETSI-0695-TD-50 is a summary of NA5 (Network Aspects-Broadband) activities on broadband. Items noted include possible collaboration with the ATM forum. It was provided for information to TE members since some NA5 activities may result in work items initiated by TE, in particular TE5. ETSI-0695-TD-33© is a liaison from TC Human Factors (HF1) to TE4 and NA6. It provides comments on the liaison from NA7 regarding Card Reader Device and Card Reader Terminals. In this document, HF recommends that such a work item be started within HF in close cooperation with TE. ETSI-0695-TD-59© is also a liaison from HF1. It deals with DE/HF-01017, “Minimum Man Machine Interface for Public Network-based Supplementary Services.” There were a number of negative reactions from TE members to this liaison. T. Ulseth (Telenor AS) stated that HF members cannot generalize from PSTN to all networks and that they do not have the expertise for ISDN-related work. The document from HF should be an ETR, not an ETS. The idea that HF be absorbed by TE has been contemplated but dropped, according to G. N. Lawrence. ETSI-0695-TD-88 is a draft liaison statement in reply to HF stating that the subject would be better dealt with at a more general level in an ETSI Technical Report. ETSI-0695-TD-32 is a liaison from G. Brusasco, the TC MTS (Methodology of Test Suites) Chair, originated by PT65V (Project Team 65 Voluntary), to use the TE1 PT75V as a test vehicle for SDL (Specification and Description Language) implementation. H. Layec, TE1 Chair, indicated the following: • The choice of SDL by PT75V has not yet been made • IDL may be a better fit • IDL is an Interface Design Language as opposed to SDL which is a Protocol Design Language • Other standards groups use IDL (e.g., ISO’s DSMCC [Digital System Multimedia Communication Control] ) • IDL is better than SDL for Object Management Group. H. Layec agreed to draft a position paper explaining to ETSI TA why IDL is more appropriate than SDL and will send a liaison to PT75V on the matter. ETSI-0695-TD-51 is a liaison from the Business Telecom Committee (BTC) Chair regarding continuation of TM5 (Coding Speech Processing and Associated Network Issues) work items related to transmission planning. TCC had previously allocated this continuation of work to TE4 (Voice Terminals), and BTC2 is challenging that decision. After some discussions, TE members agree that the TCC decision to allocate the continuation of work from TM5 to TE4 was well-sustained and that BTC2 be asked to send its experts to TE4 meetings. ETSI-0695-TD-53 is a summary of the work on broadband access specifications by the BTC. It indicates that rapporteurs of the different ETSI TCs will start meeting regularly to coordinate work on B-ISDN Access Specifications. ETSI-0695-TD-64 is a liaison statement from STC SPS3 (Digital Signaling) regarding harmonization and cooperation on directory service conformance testing. It proposes setting up a joint SPS3/TE6 (Directory Systems) activity for performing the TSS (Test Suite Specifications), TPs (Test Protocols), and TCs (Test Cases) for the SCF- SDF (System Directory Function-System Communication Function [Intelligent Network]) interface based on the post- 1993 X.500 set of directory service recommendations. It also includes updated terms of reference for the extension of

PT53 ATS/PIXIT (Abstract Test Suite/Profile Initialization for Test Cases) for INAP (Intelligent Network Application Profile) CS-1 (Capability Set 1). ETSI-0695-TD-65 is a liaison statement from STC SPS3 providing technical comments and proposed additions to PT20 conformance test deliverables. It also includes the identification of tests for the SCF-SDF interface, a proposed enhanced TSS for the SDF (DAP-DSA), and a test suite structure for DAP-DUA. LIAISONS OUTSIDE ETSI

Ewos European Workshop on Open Systems EWOS is aimed at the rapid development of profiles and corresponding conformance test specifications for the worldwide and European functional standardization process organized by ISO/IEC JTC1/SGFS (Special Group for Functional Standards), CEN (Commission Europeenne de Normalisation)/CENELEC (Commission Europeenne de Normalisation Electrotechnique), and the relevant profile development for public networking functions organized by ETSI. EWOS, in a similar way to ETSI, is undergoing an identity crisis and has asked in a questionnaire how EWOS members (ETSI members are excluded) and customers of EWOS see the role of EWOS in the future. ETSI-0695- TD-11 reports on the EWOS evaluation team findings. Some key points of interest include: • There is a perceived need to promote a greater awareness of EWOS and its work at both the European and international levels. • A broader participation in EWOS is being encouraged. • The concept of “Paid Editors” is being proposed in preference to the use of Project Teams. • The need is seen for EWOS to take the lead in EII work, and for it to attain the same status a ETSI. • Concern is expressed regarding the high level of consultants participating in the work of EWOS. • ED/EN(V)/ISP approval processes need to be streamlined/synchronised. • Collaboration with ETSI should be promoted/enhanced. G. N. Lawrence, TE Chair, reported on EWOS TA29 in ETSI-0695-TD-27. J. Pointer, PRO TE Vice Chair, reported on EWOS TA28 in ETSI-0695-TD-12. A proposed EWOS EG (Expert Group) new work item on SMMI (Single Man Machine Interface) was of interest to TE4 STC and was presented in ETSI-0695-TD-36. Due to lack of time and lack of an EWOS representative, little discussion took place. CENELEC Commission Europeenne de Normalisation Electrotechnique Liaison with CENELEC takes place for the ISPs and for EMI related matters. No documents were introduced. TE5 (General Terminal Access Requirements) was still looking for a Rapporteur for EMI liaison with CENELEC and a Rapporteur for protection. ISO/IEC JTC1 ETSI-0695-TD-48 (ETSI Director) describes the relationship between ISO/JTC1 and ETSI. While ETSI is recognized as a regional standardization body dedicated to Europe, ISO/JTC1 recognizes the fact that ETSI could become a member of ISO. The status of ETSI as a member of ISO will vary from ISO Subcommittees to ISO SCs. Those different possible statuses are outlined in Annex A of ETSI-0695-TD-48. Communications Standards Review J. Besseyre (AT&T, France) introduced ETSI-0695-TD-35 informing TE members that beginning with this meeting, he will report on the ETSI TE Plenary progress for Communications Standards Review. ITU-T ETSI-0695-TD-22 was introduced by H. Layec, Chair of TE1 STC. It requests information regarding rules for ETSI members when introducing contributions to ITU-T. H. Layec strongly stated that if no answers were received before the next TE Plenary, he will make contributions without following any ETSI rules. PROGRAM ADVISORY COMMITTEE

The Program Advisory Committee (PAC) is an advisory committee to Technical Assembly and does not direct any TC, such as TE. PAC is looking at ways to coordinate the IC (intelligent card) activities within ETSI. SMG (Special Mobile Group), TE9 (Card Terminal) and DECT (Digital European Cordless Telephone) are presently working on card standards, more or less ignoring what the other committees are doing, to the detriment of the user. Naturally, other non-ETSI Standard organizations are also involved. The merging of banking cards, pay phone cards, GSM cards, and DECT cards will be in the user’s best interest. TE will have to wait for recommendations from TA to act.

STANDARDS MANAGEMENT

Two temporary documents regarding PRO (Planning and Reporting Officer) were tabled: ETSI-0695-TD-13 highlights the active and planned TE Project Team statuses. ETSI-0695-TD-14 is the PRO Report to ETSI TC TE. In it, PRO re-states: • The rules to be followed for the management of work program revisions • The TE procedure for STC reporting of work • The TE procedure for approval of deliverables. In a discussion regarding quality matters, it was determined that ETSI documents appear to bear a good quality reputation. However, there is a problem with the long delay in producing the documents, particularly with the time that elapses between the start of Public Enquiry and the publication. It was proposed to evaluate the possibility of shaping up the document between STC and TC approvals, and to use electronic distribution wherever possible. ETSI-0695-TD-42 (ETSI Director) introduces a measure of the complexity and quality of documents (not the technical quality but the format, the ETSI style sheet, and the PNE [Production of Norms in Europe] rules observance). It illustrates that TCs having the best documents appear to produce the shortest documents. The piece that is missing, according to J. Long (Racal-Datacom), is feedback from the ETSI Secretariat on the problems encountered with the documents. ETSI-0695-TD-43 looks at the delays curing TC’s resolution of comments received at Public Enquiry. Regarding how to reduce those delays, it was agreed that it is hard to predict the date and duration of the PE (Public Enquiry) comments meeting, since it is not known what comments are going to be made. It was suggested that comments to a PE should be classified in clause order and that comments of general nature which don't propose a specific solution to modify the text be ignored. Several delegates noticed that the members who prepare the technical documents are not the same people as those who vote (NSO, National Standard Organization); this is quite different from other standardization bodies in which they are usually the same people. ETSI-0695-TD-44 gives the status of the budget allocation by the Commission and the use that has been done by each of the "Voluntary" project teams (voluntary means funded by the Commission). As far as TE TC is concerned, the following PTs were funded in the initial allocation: API for File Transfer over ISDN, Test Specification for ISDN PCI extension, and ISDN Video phone test - B Channel. Testing methods for intelligent cards and alignment of TBR8 with TBR3 were funded in the second allocation. ETSI-0695-TD-60 gives the TA decisions regarding the final report on Project Team (PT) Mechanisms and how they are funded. Principle 1 states that the ETSI membership fees will be reduced and those Project Teams which are part of the CWP (Cost Work Program) will be more and more funded directly by the members with some overhead to pay for ETSI staff and office space and support. Principle 2 states that members may provide experts rather than money and that PT meetings may be held elsewhere than in ETSI Headquarters. Principle 3 states that technical management by the PT Steering Group is essential for the successful outcome of the Project Team; however, there will be no additional financial responsibilities given to TC Chairs. Those responsibilities lie with the ETSI permanent staff. Principle 4 states that the recruiting of members for PT should be improved. Some standardization bodies (like fora) generate standards faster than ETSI, and ETSI has been looking for a way to be able to integrate those PASs (Publicly Available Specifications). A process is now defined in which TA will be mostly implied. A new type of document is created which is called a Technical Specification (TS). This TS will have an ETSI reference but will not necessarily carry the ETSI style sheet and may not follow the PNE rules. The process of how to bring changes to those TSs has not yet been defined. Permanent documents TE(95)-52 and TE(95)-58 propose merging of TA and GA. Permanent document TE(95)-60 makes a recommendation on how to speed up the process of generating documents. This procedure will be used until the next TA meeting. Permanent document TE(95)-61 is a brief statement by the ETSI Director about IPR (Intellectual Property Rights). Permanent document TE(95)-69 gives clearance to the STC Chair to conduct indicative voting without recording the position of each number, without the formalities of voting at the TC level, and without requiring secret ballot. ETSI-0695-TD-41 (ETSI Director) revises the method of introducing an ETSI TC-generated contribution in ITU-T. The contribution must be introduced by a member of ITU-T, but that member does not need to be the chair or the rapporteur of the subject contributed. It may be presented on behalf of a number of ETSI members. Other members of ETSI may contribute on the same topic but must clearly indicate that their contributions are from their companies and not on behalf of ETSI.

N EW AND CHANGED WORK ITEMS

ETSI-0695-TD-4 lists documents approved by TE via correspondence since the December 1994 plenary. ETSI-0695-TD-8 lists work items which are behind schedule at various stages of the approval process. ETSI-0695-TD-9 lists the documents to be approved at this TE Plenary meeting. ETSI-0695-TD-10 lists the work items which have not progressed since the TE plenary one year ago. Permanent document TE(95)-11 gives the shortened work item list assigned to TE as of May 1995. PSTN MANAGEMENT

The representative of the Commission indicated that the Council (of Ministers) has reached a first level of agreement on the ONP (Open Network Policy) Voice Telephony Directive. It will be submitted to the European Parliament, and should be approved by November 1995. ETSI-0695-TD-16 (C. Harley, ETSI Secretariat) is the report of the TRAC (Technical Regulations Application Committee) ad hoc meeting on PSTN matters. It outlines the scope of a Voice Telephony CTR, and will be presented at the next ACTE (Approvals Committee for Terminal Equipment) meeting. This TBR would be composed of an access TBR based upon TBR21, additional telephony requirements such as those needed for the powering by the telephone terminal network, and additional functional requirements such as acoustical quality. After ACTE agrees on a scope statement, ETSI will be asked to initiate work on that subject, and TA will delegate the work to TE. TE4 will continue work on its I-ETS handset telephony requirements. This work will be used for further harmonization in the voice telephony TBR. C. Harley, who is also PSTN Rapporteur for TE5, will convene a meeting to prepare a scope statement that can be approved by TRAC by mid-September. After some discussion, a consensus was reached that nothing should be attempted to destabilize the TBR21 (for non- voice) process. Once TBR21 has been approved, TBR voice can pick up TBR21 in whole or in part or it can limit itself to TBR21 which is another matter. It was suggested that the scope of TBR voice be picked up from the scope of TBR8 and that the 3.1 kHz service not be limited to ISDN. Voice TBR may have to include transmission quality parameters, and voice transmission experts were invited to attend TE4 meetings for that purpose. Close collaboration between TE4, TE5, and BTC2 will be needed to progress that TBR rapidly. ETSI-0695-TD-86 contains comments sent by Telefonica on the indicative voting by correspondence to obtain approval for TBR21 to go for Public Enquiry. ITEMS RELATED TO COMMISSION OF THE EUROPEAN COMMUNITIES

The Commission has asked ETSI to look at three new mandates: Hyper LAN, Corporate Network Standardization, and Access to SDH (Synchronous Digital Hierarchy) Leased Digital Bandwidth STM (Synchronous Transmission Mode) N1 and N4. For the last mandate, TE5 would monitor the work of BTC and participate in the approval process of any document produced by BTC (Permanent document TE(95)-71). The Commission is in the process of revising the way it handles its mandate to ETSI and also the way it is going to finance those mandates. The Commission now sets the following priorities: 1. ONP, Regulatory, Terminal Directives 2. Support of Industrial Policies through Standardization 3. Testing and certification 4. Other areas ETSI will have to operate more on CWP (Cost Work Program) funding and less on Voluntary Work Program funding as discussed in ETSI-0695-TD-45 (ETSI Director). ETSI-0695-TD-24 (Swedish Delegation to ACTE) discusses the concept of a Generic Access CTR. Considering that the production of a CTR is a slow process and that new networks are becoming B-ISDN fibers, it was proposed to accelerate the process by defining a generic access CTR that would define the essential requirements in generic terms and could be applied to products interfacing with facilities that are not yet covered by CTRs. It would also provide a way to filter the applicable requirements. ETSI-0695-TD-25, “Telecommunications Certification: The Way Ahead"(Commission), describes a new phase in the implementation of the Terminal directive. In it, two new terms are introduced: OTI (Open Telecom Infrastructure)

July-August 1995 Vol. 6.5 Copyright © CSR 1995 13 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS and CTE (Connected Telecommunications Equipment). These concepts are related to the forthcoming liberalization. The approval process would be greatly simplified by manufacturers’ self declaration and by limiting the essential requirements to safety, EMI, use of radio spectrum, and prevention of OTI misuse. It would also move away from the CTR approach and go towards harmonized standards. This new directive will take at least two years to come into effect, just in time for the liberalization of the infrastructure. There was no doubt that these new concepts will lead to much debate. New legislation will be presented at the Council’s autumn meeting for early advice. MULTIMEDIA PROJECT MANAGEMENT

Permanent document TE(95)-86 (B. Weber) is the report of the Multimedia Project Management committee. The Time Charts are no longer included in the report because no comments were received. The report presents work items related to Multimedia which are running late, and new work items. The criteria for inclusion of a work item in the Multimedia project plan are still under debate. H. Layec (France Télécom/DRI) stated that character sets definitions are important to Multimedia. ETSI-0695-TD-61 was introduced by the TE Chair as a periodic revision of the charter of TE, in regard to ETSI Multimedia Management. The TE Chair recalled that TE was given the multimedia management responsibility because of the high number of TE work items related to multimedia. However, if TE STCs don't participate more actively in that management work, the TE Chair may propose that TE be relieved from these management responsibilities. TE approved the document, but it may need to be revised if TE is restructured or if other ETSI changes affect the way of working in TE. (See Structure of TC TE below.) TE1, TELEMATICS: VIDEOTEX

ETSI-0695-TD-18 is the TE1 activity report. Changes to DTR/TE-01051 (real time transmission of moving video on high speed interactive networks, ~1.5 mbit/s) that are given in ETSI-0695-TD-19 were approved by TE. With these changes, the DTR can now go to publication. The TR (Technical Report) does not need approval by National Voting. Due to no contributions in the last year, DE/TE-1046 (real time interchange of MH information in retrieval services) and 1049 (video protocols & syntaxes for real time transmission of low bit rate moving video) were deleted from the Work Program. Two new work items were proposed by TE1. The first one, on interworking between Videotex and Internet (rapporteur: Swiss Telecom PTT), is meant both as the access to Internet from a Videotex terminal and as the access from Internet to the Videotex servers and database. While the TE agreed with the second work item (B channel aggregation and synchronous compression for file transfer), a long discussion started on what deliverables should be output. Finally, TC-TR reached a consensus. When the document is published, it may be considered for upgrade to the ETR level. With minor editorial corrections, this work item was approved by TE. The rapporteur will be France Télécom. ETSI-0695-TD-19 also proposes changes to the terms of reference of TE1 with extension to Multimedia Retrieval Services. TE1 will also look at file transfer over ISDN and does not wish to be limited to ISDN file transfer. ETSI- 0695-TD-72 proposes a change to the title of a work sheet; it was approved. ETSI-0695-TD-47 (ETSI Secretariat/ETSI Director) is “File Transfer standardization; inconsistency of work.” A two file transfer mechanism has been standardized for Europe, FTAM (File Transfer, Access and Management, prETS 300 410), and Eurofile transfer (prETS 300 409). Those two file transfer mechanisms would normally need two HLC info elements for DSS 1 available. The solution that was agreed upon by TE is to ask for one international FTAM HLC for DSS 1 and to continue to operate to pick up one national reserved HLC to operate Eurofile transfer on Euro ISDN. ETSI-0695-TD-89 gives updates to the TE1 work sheet on B Channel aggregation and synchronous compression, and on interaction between Videotex and Internet. TE2, TELEMATICS: FACSIMILE, DOCUMENT HANDLING AND TRANSFER

A. Giuseppini (Italian PT Ministry) reported on TE2 STC activities. These are divided into three Working Groups (WGs). In WG 1, ETS 300080, Part 1 ISDN lower layers for telematic terminals, Provision of protocols, was approved by TE to go to Public Enquiry. It is the outcome of PT51. TE was asked how to proceed with parts 2 through 7. The TE Chair will ask for an additional six month resource in the voluntary cost program from the Commission.

ETS 300 242 will undergo a major revision due to the number of changes proposed to its first edition. In WG 2, comments received during the Public Enquiry on ETS 300498, Part 1 ODA (Open Document Architecture) Communication Services - Basic Services, will be discussed at the next WG 2 meeting. Work on Part 2 of the same ETS will be undertaken by Project Team BX. Call for experts is underway. Two work items were deleted: DE/TE 02030 (testing aspects of optional application for Telematic File Transfer) and MIT 02-03 (work completed). In WG 3, ETS300325 Revision 1, Extensions on ISDN-PCI, which now includes CAPI 2.0 (Common Application Programming Interface), has progressed more rapidly than anticipated. Approval by mail from TE members is expected to start on July 1, 1995. A project team was requested for conformance testing of the new ETS. Four countries are willing to support the work. The question is whether they will support the work financially since money for this new PTs has not been allocated for the 1995 budget. The proposal that the TE Chair will carry forward to TA is to delete PT42V and transfer its allocated resources to that effort. ETSI-0695-TD-92 describes this new work item. Completion is anticipated in January 1997. The TE Chair was not very happy with the downgrade of ETS300470 (General Architecture for Programmable Communications Interfaces) from an ETS to an I-ETS. After already changing the title, the deliverable is changed again. The TE Chair recalled that this effort is funded by the Commission. It was now recommended to downgrade it to an ETR. This will not need any voting. ETSI-0695-TD-73 (A. Giuseppini, TE2 Chair) is a report on the SMG4 workshop GSM-API. The workshop introduced the concept of a general API applicable to GSM networks as well as ISDNs. The report indicates that the ETS 300325 Rev1 (PCI) may be utilized with extensions for this purpose. ETSI-0695-TD-90 expresses the views of the TE1 Chair on the topic of API on GSM. These include: • API on GSM is not necessarily the same as API for ISDN. • AT Command Set extension may be considered. • The interface between the PCMCIA card and the mobile phone varies from manufacturer to manufacturer; this interface should be standardized before standardizing the API. • One should take into account the ongoing work of the PCCA (PCMCIA Communication Card Association). ETSI-0695-TD-91 gives the revised terms of reference for the ODA project team. ETSI-0695-TD-92 gives the revised work sheet for Harmonized PCI Conformance Testing. ETSI-0695-TD-82 provides check lists for proposed new TE2 work items. ETSI-0695-TD-46 (ETSI Director) addresses the difficulties faced with the voluntary funding for the establishment of Project Team BX on ODA profiles, Part 2. TE3, MESSAGE HANDLING SYSTEM

ETSI-0695-TD-38R2 provides the status report of TE3 (MHS). ETSI-0695-TD-39 is a new work item proposal for STC TE3, Guide on Use of MHS ISPs. ETSI-0695-TD-40 is the executive summary of the TE3 April 24-27, 1995, meeting report. TE3 has so much in common with the EWOS corresponding meeting that it is difficult to find the actual contribution of ETSI TE3 in that matter. TE4, AUDIOVISUAL AND VOICE TERMINALS

ETSI-0695-TD-71 gives the status report of TE4 STC. TC TE approved the procedure of distributing the Conformance Test Suites to inband signaling in electronic form (diskettes). This is work item DI/TE-04120-2. TC TE also approved the revised TE4 work program as well as new work items in permanent document TE(95)-77. In particular, a new work item on text telephony in relation to handicapped people was approved. The representative of the Commission asks for a list of ETSI activities relating to hearing-impaired and mute people. The following documents were approved to go for Unified Accelerated Procedure by TC TE: • Draft I-ETS 300245-1 ISDN, Technical characteristics for telephony terminals, Part 1 General • Draft I-ETS 300245-2 ISDN, Technical characteristics for telephony terminals, Part 2 PCM-A law, handset telephony The following documents were approved by TC TE to go to PE (Public Enquiry): • DI/TE-04004-1 PSTN, Requirements for Handset Telephony, contained in TE(95)-80 • DI/TE-04008-4 ISDN, Videotelephony teleservice part 4 Audio aspects - Wide band (7 kHz) loud speaking and handsfree functions, contained in TE(95)-81 • DE/TE 04030 ISDN, Video conference teleservice Service Description, contained in TE(95)-82

DE/TE 04031 will be sent for PE at the same time since it was approved at the last TE plenary. Audiographic service description will not go to PE at the same time as Video conference service description. DE/TE-04093, Telephony for the hearing impaired; electrical coupling of telephone sets to hearing aids, was approved with the modifications contained in ETSI-0695-TD-70. Modifications provide references to IEC connector 8.4. In answer to questions from J. Long (Racal-Datacom), the maintenance of ETS300001 (PSTN tentative NET4) is the responsibility of TE5. An update was sent graciously by the ETSI Secretariat to the owners of the previous edition in December 1994. An update is planned as soon as French changes are finalized. The ETSI Secretariat will consider whether electronic distribution is feasible. ETSI-0695-TD-79 provides a check list for proposed TE4 new work items. TE5, GENERAL TERMINAL ACCESS

ETSI-0695-TD-67 is an update of ETSI TC TE(95)47 on the status of work in TE5. prTBR 1 (X.21 Access) is undergoing National Voting. pr indicates that the work is under development. prTBR 2 (X.25 access) is awaiting official confirmation from ACTE and then will be ready for submission for STC/TC approval to go for National Voting. Work has resumed on PSTN Plug and Socket and a report is expected at the next TE5 meeting (Madrid, October 1995). prTBR 21 (non-voice access to the PSTN) has been approved by the TC TE to go for Public Enquiry. New Work Items have been approved for Series and parallel connection to the PSTN, B-ISDN and Frame relay. prTBR3 (Basic rate ISDN) is on National voting, as well as TBR4 from BTC2. ETSI-0695-TD-76 is a proposal on guidelines issued by the TRAC Correspondent to the TBR3 project team. It gives guidelines to PT. This document, in conjunction with ETSI-0695-TD-15 (Revised Scope Statements for CTRs 3 and 4; Versions 1 and 2), led to an animated discussion. On one side, manufacturers, in general, are not in favor of edition 2 of CTR3; and on the other side, the Telecom Operators want to protect their network and place approval requirements on Terminal Equipment. No consensus could be reached. The TE Chair will generate a TE permanent document which will include ETSI-0695-TD-15 and ETSI-0695-TD-76 and will run a kind of survey among TE members to decide on a policy to follow. This package will also include ETSI-0695-TD-37 (Future work on ISDN access TBRs 3 and 4 from J. Horrocks, BTC2 Chair) and ETSI-0695-TD-66 (Status of the preparation of TBRs 3 and 4 and future activities). Concerning essential requirements, the sentence of the Commission representative was "If in doubt about essential requirements, leave it out." ETSI-0695-TD-94 (DTI) addresses the completion of TBRs 3 and 4 and expresses its views concerning the ISDN access TBRs. TBR21 has been approved both by TE5 and TE to go to Public Enquiry. Work on the ETR on common interpretation of essential requirements for the attachment to PSTN should continue; and if possible, a meeting should be held prior to the next TE5 meeting. TE5 monitors work on advice of charge and on calling line identification. TE5 has found a Rapporteur for safety-related matters and is looking for Rapporteurs for EMI-related matters and protection-related matters. ETSI-0695-TD-28 and ETSI-0695-TD-34 were introduced. ETSI-0695-TD-28 describes the present confusion concerning the deadline date of January 1, 1996, for CE Label and EMI Directive which is due to the non-publication of EN55022, 1994 version, in the EEC OJ(Official Journal) and the ongoing work on immunity standards EN55024. ETSI-0695-TD-28 indicates that currently there are no Telecom Equipment EMI product standards and, as such, only generic product standards apply. ETSI-0695-TD-34 is a request from J. Besseyre (AT&T) to discuss CE Label for terminals with respect to the deadline and in relation to EMC. As a reply to the concerns expressed by J. Besseyre and supported by other manufacturers, the Commission representative provided ETSI-0695-TD-81 which gives some answers to the questions raised. It discusses the provision of the Council of Ministers Directive 93/68 of July 22, 1993: CE marking of equipment for which a CTR exists will come into force on an optional basis in January 1995 and will be mandatory after January 1997. A new work item for monitoring work on B-ISDN, frame relay TCR-TR was approved. ETSI-0695-TD-78© was provided for information to TC TE members by Siemens and PTT Austria. This paper, Translation of Multimedia User Requirements into ATM Switching Requirements by Using Appropriate Transport Protocols, was presented to the International Switching Symposium. It compares the functionality of TCP (Transmission Control Protocol) with a new protocol called Transport and Internetworking Package (TIP) which also includes the functions of the network layer.

ETSI-0695-TD-23 is the Common Technical Regulations (CTR) Handbook. CTRs became effective November 6, 1992. Previously, NETs (Normes Europeennes de Telecommunication) were produced. Existing NETs must be considered for transposition into CTRs. CTRs apply equally in all countries of the EEA, as the same regulations must be applied everywhere. Under normal procedures, ETSI will produce the Technical Basis for a CTR (TBR). This is a special type of ETSI deliverable with the formal status of a Harmonized Standard, produced in accordance with ETSI rules. It can draw on requirements from various European Telecommunications Standards (ETSs), other base standards, or elsewhere, for a set of specifications and tests for type certification of terminals. In issuing a mandate for ETSI to work on a TBR, the Commission, with the Approvals Committee for Terminal Equipment (ACTE), defines the requirement and scope statement for the new CTR after advice from the Technical Regulations Application Committee (TRAC), which consults ETSI on technical matters as appropriate. Based on the scope statement, ETSI will define a complete Work Package containing all technical work required to elaborate the TBR, including any work supporting ETSs. ETSI-0695-TD-31 (A. Scrase, ETSI Secretariat) is a forecast of the transfer of work items within TC TE for the end of 1995. TE5 is looking for a Secretary and is asking for help from members. TE6, DIRECTORY SYSTEMS

Permanent document TE(95)-46 gives the status report of TE6. TE6 also meets with EWOS systematically and draws ISPs (International System Profiles). TE9, CARD TERMINALS

G. Raimann presented the TE9 report in ETSI-0695-TD-74 in the absence of Mr. Bardenforth. EN 726-1, EN 726- 3 and EN 726-4 are now published standards. There is a question as to how maintenance changes can be made without waiting another two years for the changes to appear in the document. The ETSI Secretariat will investigate. ETSI- 0695-TD-75©, Draft EN 726-7 Version 8 (Identification Card Systems - Telecommunications Integrated Circuit Cards and Terminals; Part 7 - Security Module), contains the security module of these card standards. It will be approved by correspondence and will follow the CENELEC procedure. Permanent document TE(95)-44 presents a new work item for synchronous card and modifications to older work items. It was approved by TE. Some of the work item milestones need revision. ETSI-0695-TD-17 is incoming correspondence from J. L. Debecker, ETNO (European Public Telecommunications Network Operators’ Association) Secretary General, responding to the use of prepaid cards for telecommunication services. It encourages ETSI to proceed with the multi-application card standardization (including GSM applications). ETSI-0695-TD-49 (PAC Chair) gives the current status of ETSI IC card related work. The general consensus among the TE members was that the telecom industry will eventually adopt banking card standards, but it wants additional functions on the cards. A coordination group will be led by Mr. Hagenbarth (DataCom) and will include members of TE9, SMG, and, hopefully, DECT. TE10, MULTIMEDIA PLANNING AND COORDINATION

B. Schuuring, TE10 Chair, presented ETSI-0695-TD-77, the TE10 activity report. For a number of different reasons, participation in the TE10 meetings has not been high, and the Chair suggested that if things don't get better, he may resign from the job. Members of TE suggested that the TE10 meeting and the TEM (TE Management Meeting) be held jointly or during the same week. Others, as expressed in ETSI-0695-TD-68 (BT), suggested that TE10 and TE meetings be held during the same week. Still others proposed a decentralized multimedia project management in each of the TE STCs. ITU-T MMCF and DAVIC do not seem to have the same problem concerning member participation. Mr. Forsythe was appointed Rapporteur of DTR TE10012 Multimedia Project Plan. Milestone 3 (ETSI-0695-TD- 26) will have to be completed through an ad hoc meeting and by e-mail.

STRUCTURE OF TECHNICAL COMMITTEE TERMINAL EQUIPMENT

Election of Officers The March Technical Assembly re-elected G. N. Lawrence as Chair of ETSI TC-TE. G. Raimann (Landis and Gyr, Austria) was elected by TC TE Plenary as the new TE9 Chair. T. Ulseth, TE4 Chair, had previously announced that his company does not wish him to continue as Chair and that for health reasons, he wishes to resign. No candidacy had as yet been received. J. Pointer (British Telecom) informed the Plenary that his company does not wish him to continue past the end of 1995 as TE Vice Chair and PRO. G. N. Lawrence made a strong statement that if no one replaces those key elements of TE, he may himself resign. His contract with GPT runs until March 1996, and he will not ask for extension if he is not helped in his task as the Chair. B. Weber (BAPT) was appointed Multimedia Project Manager. D. Maxey, TE5 Chair, with support of his company, will continue in his role as TE5 Chair. Overall Structure K. Sambor (Austrian PTT) presented the conclusions, in permanent document TE(95)-76, of the Ad-Hoc Group on Restructuring TC-TE. Each TE STC Chair indicated the results of the discussions that took place in their Committees. ETSI-0695-TD-20 reports TE1 findings. ETSI-0695-TD-31 (ETSI Secretariat) highlights the work item numbers before and after the restructuring at the end of 1995. ETSI-0695-TD-69 (British Telecom) proposes not to split the Multimedia work into several committees. The former TE4 Chair, T. Ulseth (Telenor AS), gave his views on the restructuring of TE (ETSI-0695-TD-87). He was hostile to the split of audio coding into two STCs (analog STC and digital STC). The TE Chair recalled that several items may affect the future of ETSI TE: the High Level Task Force (whole of ETSI), PAC, and TRAC6. After a debate and a show of hands, it was decided not to modify TE4 and TE5 working attributions. It was also accepted that TE3 and TE6 will hold meetings together as much as EWOS will allow to happen, and that the TE3 Chair will report on the progress of both TE3 and TE6. The split of responsibilities between TE1 and TE2 was provisionally deferred pending further investigations. Jacques A. Besseyre, AT&T, France

ETSI MEETING ROSTER, JUNE 5 – 9, 1995, PERROS-GUIREC, FRANCE

Gerald Lawrence, GPT Limited, UK TE Plenary Chair

ETSI-0695-TD-83 lists the participants.

Alcatel-CIT, France Claude Stenstrom KPN, The Netherlands Jan B. Dietz AT&T Barphone, France Jacques Besseyre L.M. Ericcson, Sweden Per Dofnas Austrian PTT Klaus Sambor Landis & Gyr, Austria Gerhard Raimann British Telecom David Maxey Motorola, UK Graham Bewsher British Telecom Joseph Pointer National Telecom Agency, Helmer Petersen Bundesamt fur Post und Wilfried Lange Denmark Telekom, Germany NEC Technologies, UK Mark James Deutsche Telekom AG Werner Simon Nortel Ltd., UK Gary Taylor Deutsche Telekom AG Birgit Weber Norwegian Telecom. Rasmus Trevland EC/DG XIII, Belgium Brian Jenkinson Oftel, UK Philip Baxter ETSI, France Adrian Scrase PQM Consultants, UK Michael Brenton F&P Matthias FREY, Ger. Matthias Frey PTT Telecom, Netherlands Ben Schuurink France Telecom/CNET Jean-Michel Garnier Racal-Datacom, UK John Long FT/CNET/PAA/SRE/RVA, Van-Anh Hoang SAT/DEC, France Jean-Louis Lavoisard France Siemens AG, Germany Manfred Mall FT/DRI, France Herve Layec Tele Denmark Allan Buchanan GPT Limited, UK Gerald Lawrence Telecom Finland Ltd. Tapani Tuisku GPT Limited, UK Gillian Lovett Telecommunications Admin. Antero Saarinen Hellenic Telecom Org., Emilios Nikolakopoulos Centre, Finland Greece Telefonica, Spain Pablo Calvo Hungarian Telecom Gabor Nagygyorcy Telenor AS, Norway Per Heggelung Italian PT Ministry Alberto Giuseppini Telenor Research, Norway Trond Ulseth Italtel SIT, Italy Alfonso Reda Telia AB, Sweden Mikael Forsstrom

18 Vol. 6.5 Copyright © CSR 1995 July-August 1995 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS REPORT OF SG 15 EXPERTS GROUP MEETING ON G.DSVD JUNE 17, 1995, MONTREAL, CANADA The Study Group 15 Experts Group on G.dsvd is charged with developing a voice coder for digital simultaneous voice and data (DSVD) over the PSTN (Public Switched Telephone Network). The main objective of the second meeting of the Experts Group was to prepare for the selection tests of the candidate coders. DSVD-95-18 is the report of the first meeting in Geneva (March, 1995) and was approved unchanged. LIAISONS

DSVD-95-22 (J. Magill, SG 14) is a liaison statement from SG 14, where the DSVD system is being developed. This liaison first confirms the SG’s request for this new coder, the original request having come from Working Party 1/14. The main part of the liaison is the response to a request for their views on the priority of the key attributes of the selected coder from a systems point of view. Q1/14 placed the factors in the following order of preference, starting with the most important: 1. Low bit rate 2. Complexity issues (i.e., MIPS, RAM, and ROM) 3. Voice delay The weighting of these factors was on the assumption that the already-defined requirements were also met. The liaison also indicated that there was no identified need for a dual rate coder at this time and gave some information on potential DSVD applications. REVIEW OF PROPOSED CODERS At the previous SG15 Experts meeting in March 1995, five candidate coders had been proposed (AT&T, Audio Codes/DSP Group, NTT, Rockwell, and University of Sherbrooke). Two more proposals were received before the deadline. These were from IBM (DSVD-95-20) and Specom Technologies (DSVD-95-21). In preparation for the finalization of the test plan, it was necessary to agree on the number of coders that would be tested. Specom was not represented at the meeting, and as there had been no further communication from them, their coder was considered to have been withdrawn. IBM withdrew their proposal; although it was attractive in having very low complexity, they felt that it would not achieve the voice quality requirement. The Chair asked for confirmation from the remaining five proponents that they believed their coders met all the requirements in the Terms of Reference. This assurance was given by all the companies involved. Each company briefly presented a contribution giving more detail on their coder. In view of the new input on priorities from SG 14, the companies reserved the right to make further amendments to their designs prior to submission of the coders for testing. The five coders to be tested are summarized as follows : DSVD-95-24 (Rockwell International): • SCELP (Spike Code-Excited Linear-Prediction) coder • Dual rates - 8.0 and 9.6 kbit/s • 15 ms frame size • Complexity estimated at less than 10 MIPS DSVD-95-25 (NTT) • G.729 based • Rate - 7.8 kbit/s • 15 ms frame size • Complexity at approximately 10 MIPS DSVD-95-27 (University of Sherbrooke) • ACELP (Algebraic Code Excited Linear Predictor) • Rate - 10.6 kbit/s • 15 ms frame size DSVD-95-28 (AT&T) • CELP • Rate - not specified

• 15 ms frame size • Complexity approximately within 10 MIPS DSVD-95-29 and DSVD-95-30 (Audio Codes Ltd./DSP Group) • MP-MLQ (Multipulse - Maximum Likelihood Quantizer) based • Dual rate - 8.0 and 9.3 kbit/s • 10 ms frame size • Complexity at approximately 8.5 MIPS There was no time for discussion on these documents. The companies with dual rate coders will need to decide which rate will be put forward, as only one rate will be tested. TEST LABORATORIES

Prior to the meeting, no laboratories had volunteered to provide facilities for the coder selection tests. However, NTT offered to perform the host lab activities and Japanese language listening tests. The group felt, however, that it would be necessary to perform listening tests in an additional language. Again there were no volunteers, as there is a considerable amount of coder testing progress currently. As a result, it was decided that the four proponents, excluding NTT who is already providing lab facilities, would fund a commercial lab to perform English language listening tests. This is likely to be carried out by Comsat Labs, as they indicated that they could perform the tests within the required time frame. TEST PLAN

DSVD-95-23 (Rockwell) proposes a test plan for the selection test phase, based upon the selection test plan used for the G.723 coder. Although this was based on seven candidates, alternate plans for six and five candidates were provided in Annexes. The five coder plan was used as the basis for discussion, and a revised version was agreed for use by the labs. WORK PLAN

The meeting achieved the objective of preparing for the selection tests, and, therefore, the schedule was maintained to date. A meeting is planned for September to review the test results, with the goal of making a selection at that time. John Magill, Probe Communications, UK

G.DSVD EXPERTS MEETING ROSTER, JUNE 17, 1995, MONTREAL CANADA John Magill, Probe Communications, UK Chair Alcatel Italy Marco Fratti NEC, Japan Kazunari Ozawa AT&T, USA Mike Buckley NTT, Japan Shinji Hayashi AT&T, USA Dror Nahumi NTT, Japan Akitoshi Kataoka Audio Codes Ltd, Israel Leon Bialik NTT Da Co Mo, Japan Tomoyuki Ohya Bell Northern Res., Canada Rafi Rabipour Nokia, Finland Tero Honkanen COMSAT, USA Frank Corcoran Nokia, Finland Pekka Kapanen CSELT, Italy Rosario Drogo De Iacovo PCSI, UK Harprit S. Chatwal Deutsche Telekom, Germany Andrea Schimm Rockwell, USA Tom Geary Deutsche Telekom, Germany Gerhard Schroeder Rockwell, USA Jim Johnston IBM, USA Ali Sadri Rockwell, USA Huan-yu Su Intel Corporation, USA Mike Keith Sharp Microelectronics USA Douglas Miller MegaHertz Corp., USA Kurt Dobson Univ. of California, USA Allen Gersho Mitsubishi Electric Corp., Japan Yushi Naito Univ. of Sherbrooke, Canada Redwan Salami

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July-August 1995 Vol. 6.5 Copyright © CSR 1995 21 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS REPORT OF THE VERY LOW BITRATE VISUAL TELEPHONY RAPPORTEUR’S MEETING (QUESTION 2/15), JUNE 20 – 23, 1995, NEWTON, MA The ftp site for the storage and distribution of draft LBC documents is maintained by D. Lindbergh of PictureTel. The address is: ftp.std.com, directory /customer/vendors/PictureTel/h324 The June meeting of the ITU-T Experts Group for Very Low Bit Rate Visual Telephony (LBC) was organized into the following segments: • Video Coder (H.263) • Speech Coder (G.723) • Multiplex (H.223) • Communication Control (H.245) • System (H.324) • Mobile • H.26P/L • H.324 Testing • DTE/DCE Interface • Non-Conversational Services The primary purpose of this meeting was to edit the five Draft Recommendations that were “determined” at the February Study Group (SG) 15 meeting: • H.324-System • H.263-Video, • G.723-Speech, • H.245-Control, • H.223-Multiplex The resulting draft Recommendations are electronically available at the following FTP site: ftp://ftp.std.com/vendors/PictureTel/h324. R. Schaphorst, Rapporteur, presented LBC-95-201 regarding Intellectual Property Rights (IPR) for the H.324 Recommendations. It indicates that patent statements have been received from: Audio Codes Ltd., Compression Labs Inc., DSP Group, Inc., France Telecom, National Semiconductor, Sharp, Telenor Research and Thomson. SG 15 has advised the LBC Experts Group to take action on the IPR issue related to the subject draft Recommendations. The Rapporteur requested that all organizations that have participated in the development of the subject Recommendations submit the two types of IPR information identified by September 1, 1995. The Rapporteur will gather the patent information, pass it on to the ITU, and report on the status of the collection. It was expected that this information will be presented at the LBC Experts meeting October 17-20 in Darmstadt, Germany. The Ad Hoc Group on MPEG4 (Motion Picture Experts Group 4) Testing Procedures met in May 1995 to develop the test procedures to be used in the forthcoming competitive test (LBC-95-207, F. Pereira, Inst. Superior Tecnico, Portugal). A new version of the MPEG4 Test Document will be distributed around the beginning of June. The following time schedule for the video proposals was set:

July 21 Final date for pre-registration for proposals on tools and algorithms. Final version of the MPEG4 testing/evaluation document. Aug. 15 Error patterns for error robustness tests are distributed by e-mail. Sept. 15 Deadline for submission of D1 tapes, decoders and bitstreams for formal testing. Oct. 15 Deadline for submission of technical descriptions, D1 tapes for demos and proposal of tolls and algorithms addressing functionalities not covered by the set of tests specified in the MPEG4 Test Document. Oct. 30 Start of formal testing (Hughes - Los Angeles). VIDEO CODER (H.263) The Chair of this work was K. Rijkse, PTT Research. DRAFT RECOMMENDATION H.263

LBC-95-163©, draft Recommendation H.263 , “Line Transmission of Non-Telephone Signals; Video Coding for Narrow Telecommunication Channels,” dated June 1995, was reviewed. Changes introduced since the last meeting were approved. Additional modes for B-blocks were discussed (i.e., an INTRA-mode, forward prediction only, and

weighted bilinear interpolation). No additional modes of the current PB-frames technique were adopted since no experiments were made to see whether additional options made any further improvement. A proposal was made for a new definition of DQUANT in order to allow a faster update of quantizer than in the current definition. However, in an earlier stage, experiments were done to improve DQUANT, but it was not easy to improve the buffer regulation with new definitions of DQUANT. As no experiments were made with the proposed definition, it was decided to keep DQUANT as it is. It was also proposed to have the possibility of four vectors per macro block (currently only used as part of the Advanced Prediction mode) as a separate option for H.263. This proposal was not adopted. A simplification of the interpolation for half pixel motion compensation was discussed. A lot of possibilities were investigated, and Telenor kindly volunteered to do experiments during the meeting in order to provide information helpful for making a decision. Finally, it was decided to use truncation instead of rounding in the situations where rounding does not improve the accuracy. It was proposed to add the 4CIF (704x576) and 16CIF (1408x1152) picture formats as options to H.263, not for still pictures but for (very) low frame rate video. This proposal was adopted, while another proposal for a more general indication of the size of the picture format (number of macro blocks in horizontal and vertical direction) was not adopted. As very low frame rates may occur, it was decided to increase the number of bits for the temporal reference of the picture from 5 to 8. As it is likely that these very large picture formats require more bits per picture than, for example, QCIF, the minimum buffer size as specified by Annex B of H.263 will depend on the picture format. LBC-95-169 contains a report of the General Ad Hoc Committee. It addresses H.263 text, a proposal for new interpretation of COD=1, artifacts with PB-frames, H.263 as an option for H.320, picture formats and GOB (Group of Blocks) structure, MPEG4 tests, and H.263 software. LBC-95-185 (Telenor) lists some simulation results using the Syntax-based Arithmetic Coding (SAC) mode in version 1.4a of the available H.263 software. The mean SAC gain (with no other options than SAC) was 4.6%. It was provided for information. H.263 FOR H.320

The H.263 software encoder and decoder (version 1.4a) developed by Telenor Research is available by ftp from blonde.nta.no in directory /pub/tmn/software H.263 significantly outperforms H.261 at ISDN rates as well as PSTN rates. LBC-95-190 (Deutsche Telekom, Germany) is a proposal to adopt H.263 as an option for H.320. After adoption of this proposal, the consequences were discussed. Based upon this, a list of consequences (not necessarily complete) for the H.320 set of recommendations is included here: • Add new capabilities for H.263 (picture formats, coding options) to Recommendation H.221 Annex A-6, as much as possible in line with the H.245 commands. • Add capabilities for the H.263 Continuous Presence Multipoint (not used in H.245, as H.324 supports multiple video channels). • Redefine the name of the H.261-command in Recommendation H.221 Annex A-320 to video on, or activate the Vid-imp(R) command. • Extend chapter 3.3.3 in Recommendation H.320 in order to allow the optional use of H.263 encoded video. • Replace the wording “H.261” by “H.261/H.263” at several places throughout the H.320 set of recommendations. • Bit 6 of PTYPE in H.261 should always be set to 1 for distinction between H.261 and H.263 (since H.261 and H.263 will both be used in H.324, this was proposed even if H.263 was not adopted as an option for H.320). LBC-95-196 (D. Lindbergh, PictureTel) proposes that optional 4CIF and 16CIF modes be added to H.263. In H.320, it is possible to have Continuous Presence Multipoint (CPM) in a multipoint connection by combining four QCIF (Quarter Common Intermediate Format) pictures into one CIF picture. In H.324, this would be solved by opening four logical video channels. However, if H.263 should be used in H.320 as well, a means should be provided to support CPM also within H.263 itself. This is solved by allowing a sort of logical channel within one H.263 bitstream. In Picture and GOB headers of QCIF pictures, the number of the logical channel is indicated, while the four QCIF pictures are decoded separately. This type of logical channel should not be used for H.324. Additionally, it was proposed to change the title of H.263 to “Video Coding for Low Bitrate Communication” and remove the 64 kbit/s restriction. The references to H.263 in the H.324 set of Recommendations must also mention this new title. Addi- tionally, it was proposed to add an annex to H.263 in which an error correction framing and error correction code are described for use of H.263 over ISDN . Both the framing and the code could be the same as for H.261.

SYSTEM RELATED ASPECTS

The parts of H.324, H.223, and H.245 that were important for video were reviewed. In a joint session with the systems group, all questions and proposed amendments related to these Recommendations were discussed. MPEG4 TESTS

It was proposed to the Chair of the MPEG4 Ad Hoc Group on Tests to have the H.263 material prepared by the ITU LBC group, in order that the relationship between the LBC group and MPEG4 could be strengthened. He welcomed this idea and strongly supported closer collaboration with ITU. The H.263 material will be used as an anchor point in the compression tests at 10, 24, 48, and 112 kbit/s. The MPEG4 test sequences to be used are class A (simple), class B (more complex, including Foreman), class C (very complex), and class D (hybrid synthetic and natural data). Telenor kindly volunteered to prepare the test material. Picture formats and frame rates were discussed. As some of the MPEG4 test sequences are 25 Hz and some are 30 Hz, the frame rate may depend on the sequence. Whether adaptation of coding parameters per sequence or class of sequences is needed and/or allowed will be discussed by the Video Ad Hoc Group in close cooperation with MPEG4. It is possible that a buffer regulation needs to be used if both a fixed bit rate and a fixed frame rate must be used. It was proposed to send a liaison statement to MPEG stating that ITU is willing to provide the H.263 material for the MPEG4 tests. (See also the mobile ad hoc report below.) SPEECH CODER (G.723) The Chair of this work is R. Cox, AT&T Bell Labs. DRAFT RECOMMENDATION G.723

The group thoroughly reviewed the text of draft Recommendation G.723, Dual Rate Speech Coder for Multimedia Telecommunication Transmitting at 5.3 and 6.3 kbit/s (LBC-95-165), and recommended a variety of editorial changes. These changes were made in LBC-95-232, which brought the document into further conformance with the C code, clarified ambiguities, and corrected minor items of style. IMPLEMENTATION TEST VECTORS

France Telecom (FT) presented LBC-95-219 regarding the preparation of test vectors for G.723. They have prepared sequences which test most, but not all, operations within the coder. FT/CNET agreed to provide a preliminary version of these test vectors to all interested LBC participants when they become available. This should be prior to the October LBC meeting. Once others who have attempted DSP implementations have the chance to experiment with the sequences, modifications can be made as necessary. When this work is complete, the resulting test sequences will be forwarded to the ITU and a white document announcing their availability and use will be prepared. NEW VERSION OF THE C CODE

The proponents will soon complete a new version of the C code for distribution. It will contain several minor corrections. It will also include the re-ordered bitstream agreed to by the MUX (Multiplexer) group during the March 1995 LBC meeting. It will be automatically distributed to all organizations that received the first version of the C code. SILENCE COMPRESSION

The Speech Coder group reviewed the approaches taken by the two proponents. The performance of the entire silence compression system depends on how well each of its components performs. The following elements compose the system: a voice activity detector (VAD), a comfort noise generation frame, and a comfort noise generator (CNG). Agreement was reached that a suggested, but non-mandatory, VAD will be developed by AudioCodes, Ltd., based upon parameters computed in the encoder. It had been previously agreed that the first two bits of all frames provide information on the rate and VAD information. At this meeting, it was agreed that the comfort noise generator frame will consist of these 2 bits, 24 bits for the LPC (Linear Predictive Coding) information, and 6 bits available for the energy information. Multiple updates of comfort noise generation during a non-speech interval will be possible but will depend on the stability of the noise. The VAD will include thresholds that determine when changes in spectral content or level indicate that a CNG update is advisable.

The proponents have agreed to work together on finding an approach for comfort noise generation which combines efficiency, low complexity, and high quality. Their selection of an approach will determine the quantization method used for the energy information transmitted in a comfort noise generation frame. The proponents will provide information and details on the agreed upon silence compression scheme at the October meeting of the LBC group. This will become the basis for a proposed Annex A of G.723. Exact details will be provided in ANSI C software. It is anticipated that this could be put forward for determination at the November 1995 SG 15 meeting. Before the annex can be approved, the performance of the system will need to be evaluated in two separate ways. The first is a statistical evaluation of the bit rate reduction accomplished during a body of conversational speech. The second is a subjective evaluation indicating the performance with and without the silence compression system in operation. A proposed subjective test, similar to the one performed in December 1994 by France Telecom/CNET, was proposed. FT/CNET has agreed to perform such a test and will replace the degradation category rating experiments with comparison category rating experiments. Conversational testing is also desirable and could be carried out as part of overall H.324 testing. The group also reviewed the wording of section 6.5 (audio channels) in draft Recommendation H.324, LBC-95-167©. FLOATING POINT SPECIFICATION OF G.723

LBC-95-192 (Intel) describes some characteristics of a floating point specification for G.723 and gives a progress report on Intel’s efforts to create this specification. Intel stated that they were preparing ANSI C floating point code for an interoperable floating point version of G.723 in order to produce a floating point specification of G.723 that would be included as Annex B of G.723. Also needed would be a set of floating point test vectors and an implementation verification procedure. A floating point specification for G.723 would need to be evaluated in a formal subjective test using A-B comparisons between the reference fixed-point coder and the possible floating point/fixed point combinations. A proposed subjective test was discussed. It would be quite large. Before any test is performed, the group would want to see evidence that the proposed floating point specification would be likely to interoperate well enough to pass the test. It is expected that the first version of the code will be distributed around September 15, 1995. Based upon how quickly this work proceeds, it may be possible to put forward Annex B in November 1995. Intel, National Semiconductor, and Philips are all interested in this activity and indicated willingness to participate. Intel agreed to act as coordinator for the activity. Others wishing to collaborate should contact M. Keith of Intel. The group discussed intellectual property concerns about the specification in terms of floating point C code. This code would most likely run much more efficiently on general purpose computers than the fixed point C code and could be quickly turned into commercial products. Intellectual property rights would need to be safeguarded. OPERATION OF G.723 FOR MOBILE

The group reviewed the following documents: • LBC-95-182 (AT&T, CLI, PictureTel, Rockwell, NCS, VTEL) proposes using the GSTN H.324 protocol without modification over wireless networks. • LBC-95-188 (R. Cox, AT&T) addresses the bit error sensitivity of G.723. This is a preliminary study of the draft recommendation to determine if it is suitable for use in a mobile environment. The bit error sensitivity of G.723 is similar in pattern to those of North American Digital Cellular Standard IS-54 (VSELP). The report also notes that U.S. TIA TR-45 is considering replacing IS-54 with G.729 (8 kbit/s) as G.729 is more robust for both noisy and fading channels. Therefore, at worst, if channel error protected G.723 could not provide sufficient quality, then G.729 could replace it with a channel rate of 13 kbit/s. LBC-95-188 concludes that it would be unnecessary to create any new speech coders for the mobile channel. • LBC-95-193 (Delta Info. Systems, National Communications System) provides a description of mobile networks. This is a good overview document of the work in North America on wireless and cordless communications systems. It was provided for information. • LBC-95-205 (D. Lappe, Mobile Ad Hoc Committee Chair) contains a draft of Mobile Network Characteristics. • LBC-95-216 (Bosch) provides comments on a liaison on wireless (mobile) work on H.324. • LBC-95-230 (M. Frater, Mobile Ad Hoc Committee) is the response to a contribution regarding wireless (mobile) work on H.324. On the basis of LBC-95-188, it appeared that addition of a channel error correcting code can make G.723 useful for mobile channels. This also appeared to be the sentiment of the mobile group (LBC-95-230). Since there are so many mobile channels, it was agreed that it would be futile to create one universal channel coder. It was determined that an appendix to G.723 is needed that describes the bit error sensitivity of the individual bits in the bitstreams of

July-August 1995 Vol. 6.5 Copyright © CSR 1995 25 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS both the low rate and high rate coders and the comfort noise generator frames. It should be possible for members of the mobile group to perform these studies once the new version of the C code becomes available. TESTING ISSUES

The report of the Audio-Visual Test Ad Hoc group, LBC-95-178 , seeks to include G.723 in testing of the H.324 system. LBC-95-214 (F. Pereira, MPEG4 Testing Procedures Ad Hoc group) is the May meeting report of the MPEG4 Testing Procedures Ad Hoc Group. The portion regarding MPEG testing of ITU speech coders was reviewed. There were three pertinent facts. First, NTT already has the C code for G.723 and had previously agreed to process some of the other coders. They could also do this for G.723. Second, MPEG is testing coders at 16 kbit/s but has neglected to include G.728 in the test. Third, the test material includes a variety of non-speech inputs but only includes two male and two female talkers. It was felt that the number of talkers is too few to give a reliable indication of the performance of any of the coders for a wide variety of talkers, languages, and background noise conditions. This document also includes the pre-registration form for the MPEG4 first round of tests. INTELLECTUAL PROPERTY

The group reviewed LBC-95-201 on IPR statements. It was noted that two additional organizations are not included in the list. The University of Sherbrooke, one of the proponents, submitted a joint declaration with France Telecom, but it is not on the list. AT&T supposedly submitted a declaration, but a copy of the letter has not been forwarded to the LBC Rapporteur. MULTIPLEX (H.223) The Chair of this work was V. Eyuboglu, Motorola ISG. In addition to its own meeting, the LBC Multiplex Ad Hoc group met jointly with the video group. Most of the time was spent on reviewing the latest draft of Recommendation H.223, Line Transmission of Non-Telephone Signals: Multiplexing Protocol for Low Bit Rate Multimedia Communication, Version 3.1 (LBC-95-164©). The Editor explained the changes made since the last LBC meeting in Geneva. The group reviewed the simplifications to the multiplex table syntax and procedure, as summarized in LBC- 95-173 (V. Eyuboglu, Multiplex Ad Hoc Group Chair), and accepted the changes. During the review of the remaining parts of the document, a few open issues were identified; these were discussed and resolved in subsequent meetings. The following is a summary of other agreements reached at the meeting: • Keep the framed/unframed transfer modes in AL1 (Adaption Layer 1) and include a code point in the H.245 openLogicalChannel message for selecting the appropriate mode. • Keep the EI (Error Indicator) parameter, but do not specify the numerical coding of this parameter. • Reinsert the AL-DTRX.indication in AL3 of H.223. H.324 will include a statement which will require all video encoders receiving this indication to encode their next picture in the INTRA mode. • Do not allow a non-integral number of octets in AL3 AL-SDUs (Service Data Units). It was decided to make the video encoder responsible for octet alignment. The EXT octet in AL3 will be deleted. • Increase the range of LCNs (Logical Channel Number) from [0,255] to [0,65535]. • Increase the minimum send buffer size for video retransmission in AL3 from 512 to 1024. This change doesn’t affect H.223. The change will be made in H.324. The actual value of the buffer size will be indicated in the H.245 openLogicalChannel message, not in the capability message. • Keep the ASN.1 syntax for the multiplex tables in H.223. As before, in case of discrepancy between the versions in H.223 and H.245, the version in H.245 will supersede. • Include a code point in H.245 for receivers to indicate the maximum AL-SDU size they can support in AL2. LBC-95-223 (D. Helman and P. Lu, IIT) contains proposals for H.223 AL3. Version 3.2 of Draft Recommendation H.223, reflecting these agreements, will be sent to the ITU before the July 10 deadline for White Papers for the November Study Group 15 meeting. COMMUNICATION CONTROL (H.245) The Chair of this work was M. Nilsson (BT). The H.245 Ad Hoc group met separately; joint sessions were also held with the system, multiplex, and video groups. LBC-95-166© is the latest version of Draft Recommendation H.245, Line Transmission of Non-Telephone Signals:

Control Protocol for Multimedia Communication, dated June 14, 1995. The following is a list of the major agreements made during these discussions: • The master/slave determination procedure will be separated from the capability exchange procedure. They will use separate ASN.1 messages. Terminals shall be constrained to send numbers in the range 0..2^31-1 with higher numbers being reserved for future use, for example, by MCUs (Multipoint Control Units). The procedure will include acknowledgments to avoid timing problems and specify a retry mechanism for the case when the numbers are the same. • Code points were added to EndSessionCommandPDU to meet the requirements of LBC-95-218 (AT&T, Intel, Microsoft, Motorola), that is, to allow change to another service (V.dsvd) using the same modem (V.34) without the need to return to analog telephony. C. Hanson (Intel) will provide a list of code points to be added. The terminology in H.245 will be changed from Change and End session to End session. • LBC-95-208 (D. Lindbergh, H.324 Editor) proposes H.245 messages for encryption. The principle of this contribution was accepted subject to editorial changes for suitability in ATM (Asynchronous Transfer Mode) applications. • T.84 and T.434 code points will be defined in H.245, as described in LBC-95-222 (I. Sebestyen, Siemens), except that the t84Unrestricted code point should be clarified to mean capability not indicated in H.245, and that the code point in dataMode should be NULL for T.84. ASN.1 syntax will be modified as necessary to fit into the existing H.245 syntax. • It was agreed to use SDLs (Specification and Description Languages) to formally describe the procedures in H.245 as in LBC-95-221 (S. Dunstan, Siemens), which is a draft text of section 9 (Procedures using SDLs) of H.245. The SDLs will take precedence over text descriptions of procedures. The text that is currently in section 8 (Procedures) of H.245 will be moved into introductory sections of section 9. It was agreed that H.245 should clearly indicate that a reliable transport layer is required. Retransmission procedures will not be described in the SDLs. • It was agreed to define messages and procedures to allow the round trip delay to be determined; the same could be used for a keep alive function. • It was agreed that 16 bits was appropriate for the range of logical channel numbers. • The full duplex logical channel procedures were reviewed. It was agreed that these would remain essentially as in the current draft, except that the first request would specify the contents of both forward and reverse logical channels. • The resource requirements parameter was removed from the logical channel signaling messages. The channel use was defined to allow a range of modes up to an indicated maximum to be transmitted on the logical channel. • The relative merits of the current top-level structure of the ASN.1 syntax and of that agreed upon at the ATM video experts meeting was discussed. It would be desirable to be able to distinguish at the top layer between requests, responses, commands, and indications, so that important messages, such as requests and commands, could be looped back to the transmitter if they are not understood. It was also agreed that readability of H.245 would be improved if all messages related to the same procedure, such as logical channel signaling, were kept together. It was agreed to retain the existing ASN.1 structure but to reorder the definitions of messages, so that related ones were together. Messages will be given names appropriate to the function and not to their classification as request, response, command, or indication. Positive and negative acknowledgments (responses) will be defined as separate messages rather than different types of a single message. • ModeElement syntax was reviewed for suitability for use with the request mode procedure. It was required to be able to be precise about what it desired. Code points were added for G.723 bit rate and whether silence suppression was desired. It should also be possible to specify the desired H.223 adaptation type. • It was agreed that only the following H.230/H.221 C&I (Commands & Indications) type messages will be included: Loops, VCF, VCU, AV active, AV inactive, VIR, MIC, cancel-MIC, MIZ, cancel-MIZ, MIS, cancel-MIS, ACE (?), ACZ (?) (see draft H.245 (LBC-95-166©) for definitions of these commands and indications). However, if further study of H.230 results in the need for additional code points, these will be added. • It was agreed that the H.221 C&I commands like LCA and LCV are not suitable for H.245, where there may be more than one video and audio stream. It was therefore agreed to define a request message that includes logical channel number and one of “system loop,” “media loop,” and “logical channel loop.” The exact meaning of these will be system-dependent and defined in the system recommendation. • FunctionNotSupportedPDU will be used to loop back complete messages that are not understood. Requests, responses, and commands, but not indications, will be looped back. The FunctionNotSupportedPDU will be an indication message. • B. Welsh (BT Labs and H.245 editor) confirmed that there is already sufficient text to change from XID (eXchange IDentification) transmission to I-frame transmission of H.245 messages, although some further consideration of this may be beneficial. The references to XID in V.42 will be removed, and the relevant paragraphs will be copied into the protocol stack annex. They will include a note to state where the text came from.

• The definition of independent and dependent capsets was reviewed. A new proposal was agreed that makes it possible to incrementally add capsets. There will be a requirement in H.245 that at least one of the capability descriptors will be to provide the same information as that in the previous version’s definition of independent capsets. D. Helman (IIT) will attempt to combine this with his efficient representation concept described in LBC- 95-224, “Capset Negotiation Proposal for H.245.” • The code points for 4CIF and 16CIF will be added to the H.263 capability and mode messages, and the MPI (Minimum Picture Interval) will be extended to the range 1..32. A buffer size parameter will also be added. Clarification of the interaction between the H.263 options and MPI will be added. Definitions of the H.263 options will be made by reference to the annexes of H.263. • The h263VCUGOB parameter ranges will be changed to 0..17 and 1..18. • Commands to force the transmitter into a resilient mode of transmission and to release this demand will be added. • SendNFramesPerSecond will be replaced with TemporalSpatialTradeOff, which is a command with a parameter range 0..31. There will be an indication message to indicate the transmitters current value and a capability to indicate whether the transmitter is capable of changing its temporal spatial trade-off. • A code point will be added to h223CapParareters for maxAL2SDUSize. • A request and response to request the closing of a logical channel will be added. • The summary section given by S. Okubo (Graphics Comm. Lab) in his e-mail of June 16 will be added. • A code point for T.128 will not be added. This capability can be determined by running T.120. • Multi-link capability is left for future study. • The primary character set of T.51 will be used instead of T.50 characters in the UserInputIndicationPDU, for such use as DTMF (Dual Tone Multi Frequency). • D. Helman (IIT) will modify Appendix II to be consistent with the updated version of the ASN.1 syntax. • Data code points will be added for H.281 and H.224 to support this means of far end camera control. • al3SendBufferSize will be extended to the range 0..2^24-1 and will be moved from the capability message to the open logical channel message. The H.245 Ad Hoc group agreed that H.245 would be applicable for mobile applications although some additional code points may be needed. LBC-95-198 (S. Dunstan, Siemens) provides a detailed explanation of logical channel signaling procedures in the H.310 terminal. In view of the H.245 harmonization process, at the last meeting it was agreed to move the logical channel signaling procedures to H.245. The logical channel signaling SDL procedures are described in section 9 of draft H.245. SYSTEM (H.324) D. Lindbergh of PictureTel was the chair of this work. The H.324 Ad Hoc group reviewed LBC-95-167©, the Editor’s initial proposal for a white paper draft of H.324, Line Transmission of Non-Telephone Signals: Terminal for Low Bitrate Multimedia Communication. LBC-95-167© incorporated numerous editorial improvements to the text and new text proposed by the editor, which were accepted with some alterations. A number of additional editorial corrections and improvements were suggested, which will be incorporated in the final white paper draft of H.324. It was agreed that the Editor would make editorial changes to complete the document, to implement the agreed changes and additions, and to further clarify the existing text where needed. In particular, there was agreement to make the following changes from the LBC-95-167© draft: • Change “duplex” to “bi-directional” everywhere. • Add summary. • Keep framed AL1 versus unframed AL1 distinction in H.223 and add specification of “framed” or “unframed” AL1 in all cases where AL1 is specified in H.324. • Add paragraph in 6.3 (control channel) on user input (DTMF) characters. • In Scope, clarify “MCUs” to “MCUs and other non-terminal devices.” • Fix titles of H.263 and V.8 in References to track actual titles. • Update Figure 1, moving T.120 from “applications” to “protocols,” per section 6.8. • Update descriptions in 5.1.2 to track final document titles. • Add LCN range (0-(2^16-1)) to 6.2.1. • Change “may” to “shall” in last line of 6.2.2 to clarify what is already the only possible way to do it. • In section 6.6 (video), clarify that support of retransmission is required in encoders, and add minimal 3SendBufferSize of 1024 octets (moved here from H.245). • Include 4CIF and 16CIF video modes, as the video group agreed to include these modes. • In 6.6, add text explaining that video mode signaled upon opening the video LC (Logic Channel) is a maximum and that other modes up to the maximum may be used in the LC, as signaled in PTYPE.

• In 6.6, add text saying that quadranting should not be used for H.324, instead, multiple LCs of video should be used. • In 6.6.1, remove italics on AL-DRTX.indication text (after the joint video/systems group discussion, it was agreed that this is the simplest way to address this very rare case). • Add text that H.263 picture start codes shall align with AL-SDU starts. • In 6.5 (audio), change “in-band to” to “in-band in” and, as requested by the audio group, clarify that silence background fill applies only if the codec in use specifies such a mode. • In 6.8.1 (data protocols), add a new figure showing the V.24 interface to the external data application. This clarifies that the V.24 interface to the application is not the same as the interface to the modem. • In 6.8.1.3, change name “HDLC decode” to “HDLC frame tunneling” and generalize to include both sync and async V.24 interfaces. • Add H.224/H.281 data modes for far-end camera control. • In 6.8 and 6.8.1, update bullet list of data applications and other text, per LBC-95-222 (I. Sebestyen, Siemens). Break old section 6.8.2.3 (T84/T434) into two sections, 6.8.2.3 and 6.8.2.4 with text based on LBC-95-222. • Add data section for Network Link Layer (NLPID) data application, per LBC-95-227 (M. Patrick, Motorola ISG). The link layer to be used will be that defined for use with async GSTN modems. If NLPID protocol uses HDLC, HDLC Frame Tunneling data protocol will be used, otherwise use Transparent Data. • After much discussion, it was agreed to require V.8bis upon its approval by ITU-T, with appropriate procedures in section 7 to be added for this case. Until V.8bis’ approval, V.8 will be required. V.8 mode will not support “late- start” as this was deemed too complex without V.8bis. Instead, this functionality will wait for V.8bis availability. V.8 procedures are to be compatible with those in use by the installed base of V.34 modems. The Ad Hoc group will not request a V.8 code point, but instead will use the general full-duplex data code point. V.8bis code points will be requested when the final V.8bis is drafted. • In 7.4 (phase D - initialization), add text about master/slave determination and limit range for terminals to 2^30 to 2^31-1, allowing MCUs to possibly force slavery or mastership by choosing a number outside that range. • Add option to EndSessionCommand allowing a switch to another digital mode (V.dsvd, fax, etc.) at the end of an H.324 session. • In section 11 (loopback), change to terms “system loop,” “media loop,” and “logical channel loop.” Only the system loop is to be required, but users masy disable it. System loop will be applicable only to symmetrical V.34 rates, asymmetry will be for future study. • Add place holder Appendix A, based upon I. Sebestyen’s (Siemens) draft of the liaison to SG 14. Note that this will change (or become an Annex) based upon results of the V.8bis work. • Revise section 6.5.1 (capabilities exchange) to track the change in H.245 from independent and dependent capsets to a new, more general system. • In Annex A, change to move XID procedures of V.42 from V.42 into Annex A, suitably modified, with a note that the procedures came from those of V.42 XID transfer. Editor, D. Lindbergh (PictureTel) will double check the XID- to-I-mode transition procedure. • Add a bibliography. • Update exact terms and message names with the final draft of H.245. LBC-95-235 (C. Hansen, Intel) proposes the use of an ODP/ADP (Originator Detection Pattern/Answerer Detection Pattern) in-band negotiation mechanism, as used in V.42, to detect the H.223 datalink layer in H.324 terminals. LBC-95-200 (LBC Rapporteur) contains the U.S. and UK comments with their NO votes on V.8bis. LBC-95-204 (BT Labs) suggests the need to study the requirement for the use of V.8bis in H.324. LBC-95-213 contains Revision 4 of Draft Recommendation V.8bis along with a breakdown of the editorial changes that were made. LBC-95-239 contains a liaison to the Q1/14 V.8bis Rapporteur group urgently requesting that they finalize Draft Recommendation V.8bis. The Editor requested that all comments be submitted by July 1, 1995, in order to be incorporated in the white paper contribution.

MOBILE This Chair of this work was D. Lappe, Robert Bosch. LIAISON

The liaison statement from T1A1.5, LBC-95-182, was discussed in detail. It suggests that a desirable solution for mobile applications might be to use H.324 without modification over wireless networks. The response to T1A1.5, LBC-95-230 (M. Frater, Univ. of New South Wales), notes that interworking is planned to be supported by an interworking adaptor separate from the H.324 terminal, and that unequal error protection in the video adaption layer (and no FEC) appears to provide superior performance. In addition, the multiplexer H.223 requires changes (see below). SG 1 provided a liaison statement for information, LBC-95-210. In SG 1, the services for mobile and PSTN are proposed to be created in the same way. The important issue of post dialing delay was raised. MOBILE NETWORK CHARACTERISTICS The following four documents are contributions to the network chraacteristics document. All documents will be merged. LBC-95-193 (Delta Information Systems, National Communications System) provides a technical overview of North American mobile networks. LBC-95-202 (T. Ohya, NTT Mobile Communications Network) provides brief descriptions of the PDC (Personal Digital Cellular) and PHS (Personal Handyphone System) network characteristics and some of their bit error sequences. LBC-95-205 (D. Lappe, Mobile Ad Hoc Group Chair) contains a draft of Mobile Network Characteristics. LBC-95-209 (P. Perrot, Philips, France) contains an overview of the current trunked TETRA (pan European trunked digital radio) network. Interworking was discussed in detail. The final document will include a description of interworking between PSTN/Mobile and ISDN/Mobile. The document will be edited by Robert Bosch. AV.22M MULTIPLEX A performance analysis of the H.223 in mobile environments is described in LBC-95-217 (P. Crespo and J Garcia- Frias, Telefonica, Spain). The discussion resulted in the following conclusions for AV.22M: • The use of fixed length packets is mandatory. • Use a proper forward error protection for the header. • Sync flags instead of HDLC. • Spreading of the sync flag and header bits along the packet. LBC-95-206 (X. Ran, NSC) addresses errors above and below the H.223 layer in a DECT (Digital European Cordless Telephone) environment. The results in this report indicate that applying FEC mainly in the upper layer does not work well in the DECT cordless system with the current PSTN H.223. It suggests that discussions and specifications of AV.22M may need to be scheduled at an earlier date. The following time schedule for AV.22M was agreed upon: • Early July: update of Draft AV.22M by Telefonica. • Late July: comments on draft AV.22M. • Late September: Draft AV.22M implemented and verified. • October meeting in Darmstadt: Draft AV.22M ready and verified. AV.24M It was agreed to define a proper proposal for AV.24M before the next meeting with the Control/Supervision group. MPEG4 LBC-95-236, (R. Ivy, Iterated Systems, and D. Lappe, Robert Bosch) will be forwarded to MPEG 4. It notes the concerns of the LBC Mobile experts about the proposed test procedures. • One profile should be reserved for real-time (end-to-end delay <400 ms). • Accept delay constraint proposals (real-time average video codec delay 250 ms and non-real-time 0.5 sec.). • Utilize error pattern(s) representative of mobile network(s).

AV.25M LBC-95-188 (R. Cox, AT&T) performs bit sensitivity studies for the G.723. It was expected to use these results as the basis for AV.25M to be provided by the next meeting. It was decided to have the necessary modifications for AV.25M in the audio adaptation layer if technically possible. Therefore, it was anticipated that G.723 will be used in AV.25M equipment unchanged. AV.26M LBC-95-184 (M. Frater and J. Arnold, UNSW) describes results related to the experiments performed for the OKI Core Experiment (C2). The performance for both the Test Model and the OKI scheme, as implemented, were unacceptably poor. However, further study appears worthwhile. LBC-95-186 and LBC-95-187 (Telenor) present an error concealment decoder (TCON). The basic idea is that, on the decoder side, a macro block slice is assumed error free if a GBSC (Group of Blocks Start Code) header can be detected right after the end of the current macro block size. The results of simulations, ordered best to worst performance, are MTM1 (Mobile Test Model 1), TCON, and MUXdetect. Visually, the largest difference is between MTM and MUXdetect. LBC-95-191 (T. Nakai, OKI) shows the results of core experiments C1 and C2. LBC-95-194 and LBC-95-195 (Robert Bosch GmbH) describes a model based on core experiment C3. It proposes a two directional decoding scheme combined with a spiral scanning of macro blocks. LBC-95-203 (T. Ohya & T. Kawahara, NTT DoCoMo) proposes to pack a set of variable length codes into a set of the same number of fixed length blocks (bit replacement of error resilient entropy code [EREC]). It proposes a combined scheme with EREC and UEP (Unequal Error Protection). LBC-95-215 (B.G. Haskell, AT&T) describes the visual demonstration of the effects of losing parts of an TMN4 bitstream and recovery of the reconstructed pictures from such losses. Table 2 presents the agreed core experiments. The time schedule agreed upon follows: • Early July: update of Draft AV.26M by Bosch. • Late July: comments on draft AV.26M. • Late September: Draft AV.26M implemented and verified. • October meeting in Darmstadt: Draft AV.26M ready and verified. It was decided to have the necessary modifications for AV.26M in the video adaptation layer if technically possible. Therefore, it was anticipated to use H.263 in AV.26M equipment unchanged.

1 TCON LBC-95-186 Telenor, DoCoMo, OKI, UNSW, NSC, Bosch 2 MUXDETECT LBC-95-187 (Telenor), AT&T, UNSW, NSC, Bosch 3 RETRANS Retransmission Telenor, AT&T, NSC 4 COMBMUX Combined simulation of Mux and video (Telenor),(DoCoMo), (Bosch), NSC 5 BACKCHANNEL Low bitrate back channel DoCoMo, AT&T, NSC 6 OTM LBC-95-133 DoCoMo, Bosch, OKI, UNSW 7 DTM LBC-95-203 DoCoMo, Bosch 8 BTM LBC-95-194 DoCoMo, OKI, Bosch 9 REDUS Use redundancy different from FEC Bosch, UNSW Table 2. Agreed Core Experiments VIDEO TAPES

Video tapes from Telenor, NTT DoCoMo, Bosch, and AT&T were demonstrated. Telenor showed the results of TCON and Muxdetect with a significant improvement of the picture quality in the case of errors without changing the H.263 standard. The NTT DoCoMo tape demonstrated the gain that is achievable by use of an error robust entropy coding scheme (EREC). Bosch showed simulations according to LBC-95-194 and LBC-95-195. A significant gain in picture quality was achieved.

H.26P/L The Chair for this work was B. Haskell, AT&T Bell Labs. This session was devoted to the development of a long term video coding Recommendation -- H.26P/L. Since SG 15 stated that the LBC Experts were to work with the ISO/MPEG4 in the development of this Recommendation, most of the meeting was devoted to the preparation of a liaison statement to MPEG4 which meets in July 1995. This liaison is particularly important, and timely, since MPEG4 is planning to perform the first round of tests of candidate systems later in 1995. It was agreed to work toward ensuring that the ultimate MPEG4 standard include a video coding profile which addresses the H.26P/L objectives. These objective are: • Significantly higher compression than H.263 • Error resilience to address the PSTN and mobile environments • Operation at very low bit rates (less than 64 kbit/s) • Low end-to-end delay • Economical implementation It was agreed that it is important to ensure the near term MPEG4 tests address the H.26P/L profile. Two liaison statements, LBC-95-234 and LBC-95-236, were prepared to ensure this objective is met. H.324 TESTING The Chair for this work was C. Gates, Creative Labs. At the previous LBC meeting, it was recognized that considerable activity was underway to develop elements of the H.324 system; work should begin on a plan to test these components. An ad hoc committee was established for this purpose, and the result of that work is summarized in LBC-95-178 (R. Schaphorst, Audio-Visual Test Ad Hoc Group Chair). In a separate session of the H.324 Testing activity, the following agreements were made: • Early tests will focus on the H.223 Recommendation in accordance with a plan defined in LBC-95-199 (Creative Labs) that defines real time tests over the PSTN. • In addition to the above tests, H.223 test work will begin even earlier using the bitstream concept. An example of an encoded H.223 bitstream will be generated and distributed to assist in testing and validating H.223 decoders. • A separate test program will be devoted to real time video coding in accordance with LBC-95-220 (France Telecom/CNET). It is anticipated that the H.223 bitstream tests will begin quickly and the real time H.223 tests will begin in September. DTE/DCE INTERFACE The Chair of this work was T. Geary, Rockwell International. The goal of this group is to define what additions, if any, need be requested from SG 14 in the proposed V.25ter for various configurations of videophone applications. During this LBC experts meeting, one DTE/DCE (Data Terminal Equipment/Data Circuit Terminating Equipment) ad- hoc meeting was held. A number of contributions assisted in the work at this ad-hoc meeting. LBC-95-210 is a liaison from SG 1 regarding network independent service requirements. LBC-95-211 (J. Magill, Q1/14 Rapporteur, AT&T Network Systems UK) is a liaison statement to Q2/15 regarding DTE/DCE signaling and control for GSTN visual telephone terminal applications. LBC-95-225 is proposed draft Annex A/V.25ter, Procedure for V.8 Call Negotiation. LBC- 95-226 contains the TSSC draft of TIA-617, Data Transmission Systems and Equipment - In-Band DCE Control. All of these documents provided valuable background, guidance, and information. LBC-95-211 also includes an invitation to LBC Experts interested in DTE/DCE work to attend the next SG 14 Q1 and Q7 experts group meeting. The subject of DTE/DCE interfacing will again be discussed. LBC-95-228 and LBC-95-229 (H. Singh, AT&T Bell Labs) are proposals which request SG 14’s consideration of several specific items. These contributions were presented and discussed at this ad-hoc meeting. The contents of these contributions present, in detail, several of the items listed in a more general sense in the previous liaison to SG 14 (LBC-95-156. After minor revisions and additions, it was agreed that these contributions would be revised and included as attachments to any liaison to SG 14 Q1 and Q7. It was agreed the Chair would draft such a liaison to SG 14 Q1 and Q7 for approval at the closing session of this Experts meeting. This draft liaison is LBC-95-238r1. It documents the functional requirements (via block

diagrams) for the DTE/DCE interface. It notes requirements for multiple logical channels, V.8/V.8bis signaling, control of error control, control/indication of V.34 data rate, and it focuses on permitting implementation of H.324 functionality when using modems connected to a PC’s asynchronous serial port (H.324 in PC with existing modem). There is an E-mail reflector for DTE/DCE related items at: [email protected]. Subscribe by sending an e-mail request to: [email protected]. H.324 NON-CONVERSATIONAL SERVICES The Chair for this work was B. Welsh, BT. LBC-95-197 (B. Welsh, BT) was used as a basis for discussion. Itsuggests that Internet access could be highly desirable for applications such as teleshopping. Therefore, the paper suggests, that an H.324 terminal should be designed to operate over an Internet Protocol stack and work in conjunction with WWW browsers such as Netscape and Mosaic. It also suggests a phased V.34 start-up to provide some level of operation with the minimum delay. It proposes to progress the work: • Draw up a list of applications. • Infer Requirements from the above. • Consider any extensions to the H.324 series needed. • Draft extensions and/or new Recommendations. It was agreed that the wide set of applications envisioned covered more than just Information Access, so it was agreed to rename the ad hoc group, “Non-Conversational Services.” There was some debate on which applications were already possible using the current draft Recommendations, and which might require extensions or would benefit from further discussion with related bodies. As a result, it was decided to send liaison statements as follows: • To SG 7, noting our interest in the use of H.324 for messaging (store/forward, answering machine, etc.). • To SG 8, concerning mixed conversational/ non-conversational services, home shopping & banking, information access, audio-visual database access, and facsimile. • To the IETF (Internet Engineering Task Force) drawing attention to and inviting their use of H.324. • To IMTC (International Multimedia Teleconferencing Consortium), who appear to be currently focused on promoting use of T.120 and H.320. The first two would append an updated version of LBC-95-197. The latter two would append a complete set of H.324 series draft Recommendations (or maybe just the relevant ftp site). Nevertheless, it was felt that the existing drafts, in conjunction with T.120, were probably already adequate to support some applications such as surveillance and information access over the GSTN from an H.324 database server. Database access over a mobile network using some existing data channels (e.g., Groupe Speciale Mobile) should also be possible because the service is not conversational. Error control by retransmission of mux packets should provide secure transport of what may be pre-compressed video/audio, even though fast intra-update requests could not be used. Fast V.34 modem startup is desirable for many information access services. A liaison to SG 14 requesting them to develop such an enhancement to V.34 had already been prepared by other ad hoc groups in LBC-95-240 (R. Schaphorst, Q2/15 - GSTN Videophone Rapporteur). This liaison notes the relationship of seamless rate change (previously requested by SG 15 to SG 14) and a rapid start-up using a phased approach (e.g., lower data rates , and/or half duplex first). To progress the work, it was requested that interested experts register with the ad hoc group E-mail reflector: reflector, [email protected], or administrator, [email protected]. In particular, experts were requested to send comments or additions to LBC-95-197 to the reflector by July 14 to enable an updated version to be sent with the above liaison documents. Also, it will be useful if people can find other contacts in their own organizations to strengthen links with bodies such as the IMTC and submit any relevant news to the reflector. Richard Schaphorst, Delta Information Systems

LBC RAPPORTEUR’S MEETING ROSTER, JUNE 20 – 23, NEWTON, MA Richard Schaphorst, Delta Information Systems: Rapporteur Australia AT&T Rich Pauls Monash University Stuart Dunstan AT&T Robert Reynolds Univ. of New South Wales Michael Frater AT&T Anthony Schiano University of Sydney Marwan Jabri AT&T Hardish Singh Canada AT&T Paradyne R.K. Smith Motorola ISG Lee Brown AT&T Reed Thorkildsen Finland AT&T Consumer Prod. GuoYao Yu Nokia Research Center Jacek Newweglowski AT&T Yong Zhou VistaCom Erkki Tanskanen Atmel Abbas Tehrani VTT Information Tech. Christer Englund Aware, Inc. Halil Padir France Aware, Inc. Jerome Shapiro SAGEM P. Sabatier Compression Labs George Campbell France Telecom/CNET Phil Boucheron Compression Labs Len Kain France Telecom/CNET Isabelle Haignere Comtech Labs Sinan Othman France Telecom/CNET Jean-Pierre Petit Creative Labs Corey Gates France Telecom/CNET Claude Lamblin Delta Info. Systems Richard Schaphorst Lab. d’Electronique Philips Franck Lecanu GTE Labs Faramarz Azadegan Lab. d’Electronique Philips Philippe Perrot Hughes Aircraft Diana Choi Lab. d’Electronique Philips Estelle Sonnic IBM Research Lurng-Kuo Liu Thomson C.E.R.D.F. Michel Kerdranvat IBM Research Wei Ding Germany IBM Bill Guckel Deutsche Telekom Peter List IBM Zon-Yin Shaz Deutsche Thomson Brandt Imre Varga IBM Marc Willebeek-LeMair Robert Boxch GmbH Ralf Fischer IIT Daniel Helman Robert Bosch GmbH Dirk Lappe IIT Paul Lu Siemens Istvan Sebestyen IIT Chris Peters Siemens AG Raphael Haerme Intel Corporation Tom Gardos Israel Intel Corporation Chris Hansen Age Computational Graphics Asaf Mohr Iterated Systems Richard Ivy Audio Codes Ltd. Leon Bialik Iterated Systems John Muller DSP Group & Tel-Aviv Univ. Yair Beery KNK Consulting Kristine Kneib Japan MCI Dianne Black Matsushita Yutaka Machida Microsoft Charlie Garthwaite NTT Mobile Com. Network Toshiro Kawahara Motorola Cheung Auyenug NTT Mobile Com. Network Tomoyuki Ohya Motorola Joe Duran OKI Electric Toshihisa Nakai Motorola ISG Vedat Eyuboglu Korea Motorola Jeff Smolinske Daewoo Electronics Jongtae Lim Motorola ISG Jian Yang LG Electronics Inc. Jungsoo Park Motorola Codex Qin-Fan Zhu Samsung Electronics Co. Kyu-Hwan Sim National Semiconductor Christa Porter Samsung Electronics Co. Gwi-Young Jung National Semiconductor Xiaonong Ran Netherlands National Semiconductor Mei Yong KPN Research Karel Rijkse Omniphone Technology Richard Greenblatt Norway PictureTel Paul Alexander Telenor Research Giale Bjontegaard PictureTel David Lindbergh Telenor Research Karl Lillevold PictureTel Paul Mageau Spain PictureTel Theresa Meuse Telefonica I & D Pedro Crespo PictureTel Jim Pan Sweden PictureTel Gary Sullivan Ericsson Radio Systems AB Goran Bang Rockwell Mounir Ayoub Taiwan Rockwell Tom Geary CCL/ITRI Hsun Chang Hsieh RTI/DCT Cliff Powers CCC/TRI Chun-Chin Hwang San Jose State Univ. Chang Choo UK Specom Technologies Yuhai Mao BT Labs Peter Salmon Texas Instruments Karen Oehler BT Labs Bill Welsh Texas Instruments Jennifer Webb BT Labs Mike Whybray Texas Instruments Fritz Whittington IBM UK Labs Ltd. Steve Wood U.S. Robotics, Inc. Steve Farkas Probe Communications John McGill U.S. Robotics, Inc. George Landsburg USA University of California John Vilasenor AT&T Bell Labs Richard Cox VoiceCraft Allen Gersho AT&T Paul Crouch VIVO Software Staffan Ericsson AT&T Bell Labs Barry Haskell Winbond Electronics Peter Hsieh

34 Vol. 6.5 Copyright © CSR 1995 July-August 1995 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS TR-30.1/TR-30.4 JOINT DTE-SAVD DCE AD HOC MEETING JULY 6 – 7, 1995, IRVINE, CA A joint meeting was conducted by B. O’Mahony, Intel, PN-3319 Editor to address several issues in DTE-DCE interfaces for SAVD (Simultaneous or Alternating Voice Data). PN-3319 is Voice/Data Multiplexing the DCEs -- DTE-DCE Interface Operations. Results included: • A proposal for a low-level DTE-DCE interface for DTE-implemented protocols • A proposal for a DTE-DCE multiplexer in configurations with distributed media I/O The following documents were provided for reference: DTE/DCE/95-07-1 ISO/IEC 3309, High-level data link control procedures-Frame structure DTE/DCE/95-07-3 draft Recommendation H.223, Multiplexing Protocol for Low Bitrate Multimedia Communications DTE/DCE/95-07-4 draft Recommendation H.245, Control Protocol Multimedia Communications DTE/DCE/95-07-5 draft Recommendation H.324, Terminal for Multimedia Communications DTE/DCE/95-07-6 TSSC draft of TIA 617 In-Band DCE Control DTE/DCE/95-07-07 PN-3131 Class 8 draft, Project to complete IS-101 Facsimile Digital Interfaces Voice Control Standard for Asynchronous DCE. REQUIREMENTS FOR DTE-DCE INTERFACES

DTE/DCE/95-07-11 (B. O’Mahony, Intel) discusses DTE-DCE multiplexing issues and requirements for V.savd and H.324 multimedia terminals. B. O’Mahony reviewed the functions of a multimedia terminal and existing PC serial ports. There are three existing models for control/media multiplexing: • Classic AT modem alternating command state/data state • Data with in-band escape (e.g., fax modems, TIA-617) • Converting the HDLC (High level Data Link Control) frames to async with DLCI (Data Link Connection Identifier) differentiation, (e.g., ETSI draft DI/TE-04114 Version 5.2 of “Integrated Services Digital Network [ISDN]; Audiovisual applications; Data port based on audiovisual in-band signaling frame structure,” as contained in DTE/DCE/95-07-02©). DTE/DCE/95-07-11 (B. O’Mahony, Intel) also notes that the TIA-617 escape character mechanism () is appropriate, particularly since it is not yet in widespread use, so there are no conflicts with multiple prior designs. It concludes with a list of the multiplexer requirements: • Support of media source/sinks in either DCE or DTE • Support of voice/video in compressed form only • Low induced latency • Maintain high DCE-DCE bandwidth efficiency • Support the maximum (DCE-DCE) line rate • Support the “realities” of PC port flow control • Allow In-Band V.25ter commands and indications • Support switching of multimedia modes. In subsequent discussion, all requirements were supported except for voice/video in compressed form only. The specific counter example is the desire to have the DCE perform audio encoding or decoding with the mic and/or speaker in the PC. The price is that the DTE-DCE data rate needs to be much higher. There was a clear consensus that the video codec needs to be associated with the video I/O (input/output) because of the huge bandwidths associated with uncompressed video. DTE/DCE/95-07-08 (T. Geary, Rockwell) is a proposed liaison from SG15 LBC Rapporteur’s Group to SG 14 Q1 and Q7 concerning DTE/DCE signaling and control for GSTN (General Switched Telephone Network) visual telephone terminal applications. It was provided for information and consists of LBC-95-238r1 (the proposed liason) document and two attachments, LBC-95-228rev1 (framed synchronous data over DCEs with asynchronous DTE- DCE interface proposal) and LBC-95-229rev1 (V.25ter extensions necessary for proper operation of H.324 over DTEs external to the H.324 terminal proposal). LBC-95-238r1 identifies distinct V.24 interfaces, in addition to the PC data port for video telephones defined in DTE/DCE/95-07-12 (Study Group 15 Q3). In one of the interfaces, the DCE contains only the V.34 modem; in another, the DCE contains the audio I/O and at least parts of the H.223 multiplexer (e.g., DSVD modem). This document spells out several requirements: • Support for one or multiple logical channels, with:

- Channel(s) for modem control/status - Channel(s) for operating channel control/status (e.g., H.245) - Synchronous data streams - Flow control on a per-channel basis • DTE-DCE control and indications for above • Support for V.8/V.8bis signaling • Provide command and control for incremental V.34 rate changes • Minimal latency and delay (target less than 5 ms) • DTE-DCE error control not required LBC-95-228r1 contains several requirements for the low level DTE-DCE interface: • Method to delimit frames transferred asynchronously between PC and the modem (e.g., TIA-617) • A mode that performs the normal HDLC framing operations of flag insertion/deletion and zero-bit insertion and deletion • A mechanism that allows the modem to generate and check CRCs (Cyclic Redundancy Codes) • V.25ter mechanism to switch the modem into these modes • V.25ter mechanism to specify the fill character sent out between HDLC packets • Mechanism to recover from transmit underrun • Mechanism to allow the modem to indicate the amount of data remaining in the transmit buffer. LBC-95-229r1 adds two more requirements: • V.25ter indication of new modem rates, if retrain has occurred. • V.25ter indication if the remote terminal is responding in analog voice-only mode. In discussion, there was little argument with any requirement except the last one, that is, to identify the nature of the remote terminal. Users of H.324 are likely to be frequently called by simple voice telephone callers. This was identified as the subject of IS-101 (Asynchronous Voice DCE Control) and its proposed replacement, PN-3131 (Asynchronous Voice DCE Control). PN-3131 work is underway in TR-30.4. However, it is clear that there will be a need to include PN-3131 into a DCE in order to meet this requirement. SUMMARY OF INTERFACES

In various papers, three interface needs have been defined: • Low level: the DCE does modulation and maybe some bit-processing (Figure 2 in H.324, right V.24 interface, or LBC-95-238r1 Figure 1) • Mid level: the DCE and DTE both handle some media I/O, the DCE includes the multiplexer (LBC-95-238r1 Figure 2, etc.) • High level: the DCE provides a data port to the DTE (Figure 2 in H.324, left V.24 interface) The high level interface is discussed in DTE/DCE/95-07-12 and is the subject of several sections in H.324. The low level interface is the subject of the proposal in DTE/DCE/95-07-10 (J. Decuir, V.25ter Editor). The mid level interface was identified as needing the most new work. PROPOSAL FOR A LOW LEVEL INTERFACE

DTE/DCE/95-07-10 (J. Decuir, V.25ter Editor) is a proposal for the low level interface. It was derived from DTE/DCE/95-07-09 (J. Decuir, T.31 Editor), Draft Annex B/T.31, V.34 DCE support for T.30 facsimile. T.31 is the ITU version of the Service Class 1 facsimile DTE-DCE specification (completed in March 1995). Draft Annex B/T.31 is an extension to support duplex and half-duplex T.30 operation on a DCE. (This has been determined for Resolution 1 treatment in February 1996.) Like H.324 and DSVD, T.30 on V.34 is based on exchanging HDLC frames, full duplex. The requirements are similar to those of an H.324 low level DCE: • In-band commands and status • Frame delimiting • HDLC and CRC services • Carrier control and status indication services Annex B/T.31 does not need any non-HDLC communication, and the CRCs are always used and are always 16-bit only. Annex B/T.31 is based upon (escape sequence) in-band data commands, as is T.31, T.32, and PN-3131. The carrier control elements, including retrain and rate renegotiation, were considered essential for H.324 support.

DTE/DCE/95-07-10 (J. Decuir, V.25ter Editor) presents a DCE capable of supporting the implementation of H.223, V.62, or V.42 with detection phase in an asynchronous DTE. It includes: • Definitions of a mark-idle synchronous mode and flag-idle synchronous mode • V.25ter extensions for selecting and indicating synchronous mode • A -based in-band command set for transparency and bit-processing control (HDLC, CRC) DTE/DCE/95-07-10 notes that, because the H.223 multiplexer can embed various sized CRCs in many places within a PDU-MUX (Protocol Data Unit Multiplexer) element, DCE support of CRC generation and checking would be impossible to include for H.223 without DCE knowledge of the current MUX Control configuration. With respect to which transparency mechanism should be used. The discussion was not conclusive. The three options are: • As written, based on , 10 hex • As in TIA-617, based on , 19 hex • As in HDLC async mode, based on 7D hex TIA-617 was written so that it would not collide with ATOK command state or based transparent data commands. Also noted, PN-3463 (Modem Command Set Bibliography) and the future V.25ter supplement need summaries of In-Band commands as well. In discussion, it was agreed that there are several elements needed to meet the requirement listed above. The following changes were agreed: • CRC changes -- indicate good or bad CRC with distinct codes, DTE explicitly controls which CRCs are generated and checked. • Add means for the DTE to control the transmit flow control thresholds. • Add overrun/underrun indication for the transmit path. • Add carrier control from Annex B/T.31. In response, J. Decuir generated and distributed a revision, DTE/DCE/95-07-10R1. After wording changes to the introduction and typo repairs, this was accepted. The ad hoc group asked that the report be sent to TR-30.1, TR-30.4, and to Study Group 15 via the two reflectors: DTE/[email protected] and [email protected]. The remaining open issues include: • Which escape character? • Packaging -- shall it be attached to V.25ter or to V.ib, or shall it be a stand alone recommendation for SAVD DCE control? PROPOSALS FOR A MID-LEVEL DTE-DCE MULTIPLEXER

The ad hoc group identified three work items for completion of a mid-level DTE-DCE interface: • A model of the elements to control • A DTE-DCE control interface • A DTE-DCE multiplexer Work focused on the last item. The system model was developed, consisting of: • A series of media sources and sinks (DTE-DCE commands, H.324 system commands [H.245], data, audio, and video) • Media stream processing (codecs, V.42/V.42bis, etc.) • Multiplexer (V.62, H.223) • Modem (V.34) The new issue, with respect to requirements, is the partitioning of elements in each media stream path. The ad hoc group persisted in the constraint that the video codec is bound to the video I/O to keep that high rate data from the DTE-DCE interface. However, there was a need identified to allow audio codec to be in the DCE, yet have the audio I/O in the PC. J. Decuir (Microsoft) made a simple model verbal proposal: • Keep the audio codec in the same device as the audio I/O. • Use the same DCE-DCE multiplexer on the DTE-DCE interface, except with async framing, as per HDLC. This requires that the DTE and DCE share the same multiplex control table for H.223 operation. • Multiplex that with the local DTE-DCE control and status channel using TIA-617. • Tolerate some redundancy. If the DCE is the media source, the DTE fills with nulls that the DCE will ignore; if the DCE is the media sink, the DCE will still deliver the data to the DTE, and the DTE may monitor or ignore. In discussion, this was considered elegant but not appropriate, for several reasons: • The desire to provide for separation of the audio codec from the I/O is strong.

• The DTE-DCE multiplexer needs are quite different from the DCE-DCE multiplexer, so they should not be tied together. Simple 5 Channel DTE-DCE MUX There was an extensive discussion of the differences between H.223 DCE-DCE multiplexer and the needs of the DTE- DCE multiplexer. The local mux needs simplicity, but with higher bandwidth; it does not need to be as efficient. It should be insensitive to the differences between H.223 and V.62 (V.gmux). A new proposal was made: • Use in-band transparency ( or ). • Define 5 markers to delimit 5 channels: local control, system control, data, audio, video. • Define 4 pairs of commands for channel specific flow control: data, audio, video, system. • The local DTE-DCE channel would be based on TIA-617. • Other media stream primitives (see H.324) would be delivered through the local control channel. The DTE might not need to act on incoming H.245 messages on the system control channel. In discussion, these were considered appropriate to use as a basis. J. Decuir agreed to draft a proposal for consideration by TR-30, SG 14, and SG 15. DTE-DCE MUX Error Control The above proposal was developed without any provisions for error control. However, it was noted that when DTE- DCE rates were 19,200 bit/s, TR-29 deemed it necessary to develop a DTE-DCE error control procedure for facsimile, TIA-605 (also, section 9/T.32). The DTE-DCE link is not considered vulnerable to bit-errors. The main hazard is loss of characters due to DTE (or DCE) latency. DTE are faster now, but the data rates needed to support uncompressed audio are 115,200 bit/s or higher. J. Decuir (Microsoft) explained how TIA-605 works, but noted that it is half-duplex and would need modification to run full duplex. B. O’Mahony (Intel) proposed a simpler mechanism: • Put superframe markers in the data every N characters. • If an error is detected by the receiver, send a NAK (Negative Acknowledgment). • The retransmitting device should lead with a channel type marker. • Audio media might not be retransmitted but, instead, discarded and replaced. J. Decuir and B. O’Mahony agreed to develop a proposal, if there is interest. VOICE

This was tabled until the TR-30.4 July meeting (see report in this issue of CSR-T). It will need to be completed for inclusion in a complete H.324/PC terminal to interwork with voice callers. The following is work that was identified as still needing to be done: • Finish low level interface (revisions to DTE/DCE/95-07-10R1). • Finish mid level DTE-DCE mux (5.4). • Define DTE-DCE control functions, semantics, and syntax. • V.8bis DTE-DCE control (e.g., TR-30.4/95-02-16, from Radish) Joe Decuir, Microsoft

TR-30.1/TR-30.4 J OINT AD HOC MEETING ROSTER, JULY 6 – 7, 1995, IRVINE, CA Barry O’Mahony, Intel Ad Hoc Chair AT&T Larry Smith Motorola Les Brown Cirrus Logic Michael Wytyshyn Radish Ann Heinke DSP Group Sandra Huang Rockwell Bernard Debbasch Intel Barry O’Mahony Rockwell Tom Geary Microsoft Joe Decuir Rockwell Glen Griffith Microsoft Charlie Garthwaite

38 Vol. 6.5 Copyright © CSR 1995 July-August 1995 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS REPORT OF TR-30, DATA TRANSMISSION SYSTEMS AND EQUIPMENT JULY 10 – 14, 1995, IRVINE, CA TR-30.1 MODEMS

LIAISONS

The June 17 Q2/15 meeting report on G.dsvd work was given informally by A. Sadri (IBM) (see report this issue of CSR-T). There are five coders being considered. A common test procedure was agreed. The coders must be submitted for testing by July 17, 1995. Comsat will be doing the testsin English, NTT in Japanese. TR-30.1/95-07-096 (J. Decuir, Acting Secretary) is a report of the DTE (Data Terminal Equipment) SAVD (Simultaneous Alternating Voice Data) DCE (Data Circuit Terminating Equipment) Ad Hoc meeting, held July 6-7 (see report this issue of CSR-T). Some general agreements were reached, but work is still needed to finish the low level interface and the mid-level DTE-DCE mux, and to define the DTE-DCE (control functions, semantics, and syntax) and V.8bis DTE-DCE control. TR-30.1/95-07-097 (J. Decuir, Microsoft) notes that three categories of interface to the SAVD DCE are needed (see Table 3). This paper proposes the first draft of an SAVD DCE-DTE multiplexer for the mid-level interface. Five channels have been identified: DTE-DCE and system control, and data, video, and audio streams. The proposal creates this mux by establishing code points for channel delimiters. TR-30.1/95-07-098 (J. Decuir, V.25ter Editor) proposes an Annex B/V.25ter. It is a first cut at defining V.25ter commands and responses to allow the use of the PC asynchronous port for synchronous data modes. This is necessary so that simple DCE can support new protocols implemented in DTE software (e.g., V.62 [dsvd mux], H.223/H.324). Description Document Low-level The DCE contains V.34, sync access V.25ter Annex B draft TR-30.1/95-07-098 and carrier control Mid-level Media I/O are distributed between DTE Mux portion TR-30.1/95-07-097 and DCE; the DCE includes the multiplexer High-level A DTE dataport is provided in a H.324 H.324 draft TR-30.1/95-07-104 terminal Table 3. Three Categories of Interfaces Needed for SAVD DCE. BALLOT RESOLUTION ON SP-3245 S YNCHRONOUS COMPRESSION

TR-30.1/95-07-078 (L. Brown, Motorola) is a summary of the balloting on SP-3245, Support for Terminal Adaptation and Data Compression in Data Circuit-Terminating Equipment with Provision for Negotiation of Parameters. There were nine yes votes, one yes with comments (ACTION Consulting), and one no vote (Motorola). TR-30.1/95-07-080 is the ballot response from Motorola. D. Cantwell (Motorola). reported that the items raised had been discussed and agreed to in the Frame Relay Forum. Each of the points were then discussed. Agreement on how to handle each was reached. TR-30.1/95-07-079 contains comments from ACTION Consulting on SP-3245. As no one was present from ACTION Consulting, the Chair covered the points raised. As with TR-30.1/95-07-080 above, agreement was reached on how to handle each point. TR-30.1/95-07-106 contains a proposed new definition section for SP-3245. There was very little discussion of this paper, and it was agreed to incorporate it in the default ballot. TR-30.1/95-07-109 (K. Schneider, Editor, Adtran) compiles a list of all of the changes to SP-3245 that were agreed to at this meeting. The revised text, including these changes, will be sent out for a 30-day default ballot. V.34 TR-30.1/95-07-082 (R. Schaphorst, Q2/15 Rapporteur) is a draft liaison to the Q1/14 V.34 Rapporteurs Group regarding fast training and seamless rate changing for V.34. Although this document is in the form of a liaison, it was introduced as a technical paper providing a ”Heads up” on work that will need to be addressed at the October Working Party meeting. The Chair introduced this paper from the Study Group 15 LBC group. It requests that a high priority

July-August 1995 Vol. 6.5 Copyright © CSR 1995 39 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS be given to a fast start-up and a seamless rate change for V.34. During the discussion, the possibility was raised to view this as a V.34bis, rather than a modification to V.34, but there was no agreement. TR-30.1/95-07-101 (G. Bremer, AT&T) proposes the study of a new SVD (Simultaneous Voice Data) modem using the QADM (Quadrature Audio Data Modulation) technology introduced in Draft Rec. V.61 based on a V.34 modem. This work is tentatively named V.34Q. The advantages that are claimed include that this would provide a low-complexity (about 15% greater complexity than V.34 alone), high performance SVD modem. Attributes include data signaling rates of 16.8/24.4 kbit/s during simultaneous voice (data rates would be switched to 28.8 kbit/s during silence), 60 ms talker-to-listener voice delay (based on 35 msec V.34 “modem delay”), and dynamically selectable audio quality. TR-30.1/95-07-102 (G. Bremer, AT&T) provides more back up material to support the claims made in TR- 30.1/95-07-101. This paper identifies important areas to be considered when evaluating SVD technologies, then provides a methodology for quantifying the potential performance of this proposal. A detailed explanation of the audio encoding and decoding is provided. This analysis is based on the use of 16 state trellis coding. It was decided that there was sufficient interest in this work to justify an informal procedure to be setup to progress this work. AT&T volunteered to provide the editor for this work and solicited input from others. (An e-mail reflector may be established.) TR-30.1/95-07-095 describes the implementation of two new optional data rates, 31200 bit/s and 33600 bit/s, that are compatible with ITU Rec. V.34. The new data rates are realized by extending the number of encoded bits from 9 bits per symbol to 10 bits per symbol. The standard V.34 algorithms are used with no further modifications. TR-30.1/95-07-095add provides a modified Table 20/V.34 to extend the new higher rates to half-duplex V.34. It was briefly introduced by the Chair. It was agreed that this contribution should go forward as a proposed U.S. contribution to the October WP meeting. G. Griffith (Rockwell) brought up several issues dealing with various ambiguities associated with specified timings in V.34 that have been raised by some Japanese companies. TR-30.1/95-07-108 (J. Viviano, Motorola) proposes that pre-emphasis be made optional in V.34 when used on cellular connections. This avoids the negative effect of the V.34 pre-emphasis in conjunction with the pre-emphasis in analog cellular phones. The paper also proposes the introduction of a calling tone for easy differentiation of modem and voice calls to cellular systems. During the discussion, questions were raised about both proposals. There was concern about allowing a modem to ignore a request for the pre-emphasis filter. (It is now required in V.34 when requested.) There were also many concerns raised about the use of a calling tone that would propagate through the network and could cause difficulty with the called modem. A point was again raised that it had been agreed at the May TR-30.1 meeting to collect all cellular information in a separate area (a V.34 Annex or a bis). It was finally agreed that the Chair would send a liaison to TR-45 on this matter. V.8BIS

TR-30.1/95-07-083 (R. Schaphorst, Q2/15 Rapporteur) is a liaison from the LBC group that requests the work on V.8bis. It requests a change in the capabilities exchange that would allow them to have a 2 level structure. It also requests that the V.8 functionality be added to V.8bis. TR-30.1/95-07-084 (A. Heinke, Radish) proposes that V.8bis not specify anything beyond country codes and that the (non-standard) provider codes be left to the T.35 governing countries for assignment. During the discussion, it was agreed that some clarification was needed. (Technical editors note: This document has since been withdrawn.) TR-30.1/95-07-085 (A. Heinke, Radish) proposes adding the capability for interoperability with V.8 and retransmission during call establishment. Interoperability for both calling or answering stations is achieved through a procedure which specifies appropriate action to be taken, depending on the signal received. It also provides for a retransmission in the event no signal is received in both cases. During the discussion, it was pointed out that these concerns may have already been addressed in the revisions and editing that took place since the earlier draft (TD-105) of V.8bis was edited. At the end of the meeting, the group came back to this document and decided that it could not be supported as a TR-30 contribution at this time, although there were no objections to it going forward to the SG 14 Working Party meeting as a Company contribution. TR-30.1/95-07-086 (A. Heinke, Radish) proposes changes to the CF (Communication Functions) coding, addressing what is perceived to be an omission in the coding that would restrict the extension of CFs. It proposes a change from bit mapping of CFs to octet mapping. (This expands the number of octets required by N to indicate N

40 Vol. 6.5 Copyright © CSR 1995 July-August 1995 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS functions.) It also proposes that the CF be followed by the appropriate CC (Communication Capabilities). During the discussion, it appeared that the CF “omission” was addressed in the revision of TD-105 (although in a different manner). TR-30.1/95-07-087 (A. Heinke, Radish) proposes the same changes to the structure of the coding of the CC field (octet versus bit) to support non-standard CCs for a standard CF and future extension. TR-30.1/95-07-088 (A. Heinke, Radish) builds on the proposals in TR-30.1/95-07-086 and TR-30.1/95- 07-087 and proposes a method that would allow indicating non-standard communications functions in the mode select message. At this point, Microsoft unsuccessfully pushed for agreement in principle to the proposals made by Radish. They developed a new contribution showing the trade-offs between the bit and octet based proposals. TR-30.1/95-07- 107 (Radish, Microsoft, and Compaq) is the comparison of the bit versus octet coding (introduced by J. Decuir, Microsoft). The paper concludes that there is no penalty in terms of efficiency by going to the octet coding and that the benefit in terms of extendibility justify the change. Considerable discussion followed, but no agreement was reached. The main point of discussion was the need for a detailed specification of “non-standard” functions. TR-30.1/95-07-089 (R. Williams, 3Com Primary Access) proposes elimination of the message type octet by taking its information into the function octet and making the preamble required only on the first message in a V.8bis transaction. AT&T reminded the group that one of the reasons for the preamble was to provide reliable operation in the presence of network echo suppressers. There seemed to be general support for the proposal to combine the message type octet with the function octet. TR-30.1/95-07-090 (M. Buckley, AT&T) is a proposal to change the coding format of the CF by following the CF with the PL (Physical Layer) which indicates which modulation modes are supported. The new CF, now referred to as the CP (Communications Protocol), proposes inclusion of such things as V.8, Analog Telephony, Data, V.dsvd, Draft Rec. V.61, H.324, T.30, Text Telephony, and Videotext. The PL indicates the modulation modes (V.34, etc.). TR-30.1/95-07-091 is the latest draft of V.8bis. The Chair conducted a detailed review of the changes made since TD-105 and obtained TR-30.1’s agreement on each change. It was agreed that, as a result of this review, this document will be the baseline document for all contributions to TR-30.1 on this matter. TR-30.1/95-07-093 (J. Derby, IBM) re-introduces the earlier IBM proposal for a “suspend-resume” function in V.gmux. It was presented by A. Sadri (IBM). Considerable discussion followed this presentation; however, no decision was made. TR-30.1/95-07-100 (C. Garthwaite, Editor) is the latest draft of PN-3131, the project to complete IS-101 (Asynchronous Voice DCE Control). It was provided for information only. TR-30.1/95-07-099 (C. Garthwaite, Editor) proposes altering the content and organization of PN-3131 to describe a general purpose voice or data modem rather than just telephone answering device features of a fax machine. TR-30.1/95-07-094 (C. Hansen, Intel) is the latest draft of the Intel proposal for DSVD (Digital Simultaneous Voice Data) control procedures. This document does not presently track with H.245. TR-30.1/95-07-105© is ITU-T Recommendation H.245, Control Protocol for Multimedia Communication. TR-30.1/95-07-092 (C. Garthwaite, Microsoft) reports on the outcome of the SG 15 LBC meeting in which a multi-company (AT&T, Microsoft, Intel and Motorola) proposal for fast switching between H.324 and V.dsvd was essentially agreed. It attempts to identify some future work. It was decided that SG 14 should expedite a procedure for fast switching between V.dsvd and H.324. TR-30.1/95-07-104© is ITU-T Recommendation H.324, Terminal for Low Bitrate Multimedia Communication. TR-30.1/95-07-103© is ITU-T Recommendation H.223, Multiplexing Protocol for Low Bitrate Multimedia Communication.

Dick Brandt, dB Consulting

TR-30.2 DATA TRANSMISSION

ITU-T S TUDY GROUP 14

Preparations are already underway for the next plenary period of the ITU-T. Although no longer necessary, a copy of the first draft of questions for the next study period of Study Group 14, Working Party 1 was distributed as TR- 30.2/95-07-018 (R.P. Brandt, Working Party 1/14 Chair). This draft proposes no major changes in the questions and does not add any new questions. It was pointed out that there is a possibility that SG 14, as it is today, may not continue in 1997. The ITU-T Advisory Committee (ITAC) has heard various proposals ranging from maintaining SG 14 to combining all Study Groups into one. One possibility would be to combine SG 8 and SG 14. The actual recommendation from ITAC will be made in 1996. TR-30.2 members were reminded that changes to Recommendations V.10, V.11, and V.24 will be presented to the October 1995 SG 14 WP 1 meeting for approval under Resolution 1. There is still time to submit additional changes to these documents before the October meeting. Once again, TR-30.2 discussed the proposal to SG 14 from ISO/IEC (International Standards Organization/International Electrotechnical Committee) to delete the 200 series circuits in Recommendation V.24. These circuits are those used in V.25 for DTE/DCE parallel interface for dialing. They appear in the US in EIA-366- A, “Interface between Data Terminal Equipment and Automatic Calling Equipment for Data Communication.” TR- 30.2 has instituted an industry ballot to withdraw the EIA-366-A standard in a parallel effort with ITU-T SG 14. This project is described in a Project Initiation Notification (PIN), TR-30.2/95-07-019, that was assigned the number PN-3589. This ballot for withdrawal should be going out within the next month. DTE/DCE INTERFACE FOR DIGITAL CELLULAR (PN-3138)

Progress was made on PN-3138, Miniature DTE/DCE Interface for Digital Cellular Equipment. TR-30.2 was awaiting a recommendation from TR-45.3 as to their acceptance of a new connector that was suggested in December 1994. Drawings for this 12 pin connector with RF capability (coax) were provided at this meeting by G. Lawrence (AMP Inc.) in TR-30.2/95-07-020. Feedback from A. Sacuta, the TR-30.2 liaison to TR-45.3, indicated that a meeting will be held within the next few weeks to formally endorse this connector and to provide TR-30.2 with the specific interchange circuits required. It appears that TR-45.3 will suggest that the connector contain 12 pins which would be sufficient for their use. If this information is received in time, it can be expected that a new draft for this standard will be available for TR-30.2 review at its September meeting. It is possible that an ANSI industry ballot could come out of the September meeting. VERY HIGH SPEED INTERFACE, ELECTRICAL CHARACTERISTICS (SP-3357)

At the May meeting, TR-30.2, considered the only ballot on SP-3357 that had been returned with comments (TR- 30.2/95-05-014, Hayes Microcomputer). The comments were of an editorial nature but were referred to the TR- 30.2 ad hoc committee on electrical characteristics for review. At this meeting, the editorial changes to the draft document were accepted by TR-30.2 members. Approval of the changes is required from Hayes Microcomputer to assure that the changes properly address their comments. Assuming this approval is received, the final copy of TIA/EIA-644, “Electrical Characteristics of Low Voltage Differential Signaling (LVDS) Interface Circuits,” will be forwarded to TIA for publication. DTE/DCE INTERFACE FOR DATA RATES UP TO 116 KBIT/S (PN-3416)

PN-3416 specifies the 25/26 pin connectors and EIA/TIA-423B electrical characteristics. The only remaining issue to resolve before this new standard is sent for ANSI industry ballot is agreement on connection options between the circuit and frame commons. Unfortunately, an expected contribution was not available at this meeting. Hopefully, this contribution will be forthcoming at the September meeting. The Chair did indicate, however, that if this proposal was not available, he would propose the draft standard be sent out for ANSI industry ballot at the conclusion of the September meeting. It is expected that this standard will be complete at the end of 1995. REVISION OF EIA-485

The TR-30.2 ad hoc committee initiated work on the revision of EIA-485, “Standard for Electrical Characteristics of Generators and Receivers for Use in Balanced Digital Multipoint Systems.” It has been many years since this standard was reviewed. It is unique since it is an electrical characteristic standard that is not referenced in any DTE/DCE interface standard written by TR-30. One area that will be revised in a new edition of this standard is application notes. A new Telecommunications Systems Bulletin (TSB) will be written that will incorporate the existing application

information from EIA-485 as well as new and additional application guidance. It is expected that this work will be completed mid to late 1996. POSSIBLE NEW WORK AREAS

A draft of the Universal Serial Bus Specification in TR-30.2/95-07-021© (Compaq, DEC, IBM, Intel, Microsoft, and Northern Telecom) Revision 0.9 dated March 31, 1995 was distributed for general consideration by TR-30.2. In addition, R. Lutz (Multi-Function Peripheral Association) presented a high level interface proposal in TR-30.2/95- 07-022 for a DDI (Direct DSP Interface). The attendees considered both of these new areas of possible standardization; although there was recognition for the need to standardize theseinterfaces, it was not clear whether they fall within the scope of TR-30.2. It is expected that additional discussions will take place at future meetings of TR- 30.2. Fred Lucas, General DataComm

TR-30.3 DATA COMMUNICATION EQUIPMENT EVALUATION AND NETWORK INTERFACES The name of TR-30.3 was changed to include the performance testing aspects of its work. LIAISON REPORTS TR-30.3/95-07-055A, FCC BillBoard for June 1995, and TR-30.3/95-07-055B, FCC BillBoard for July 1995, were distributed for information. PN-3459 MAKING TSB-37-A INTO AN ANSI S TANDARD TSB-37-A, Telephone Network Transmission Model for Evaluating Modem Performance, is a TSB, and does not have the status of a standard. This project prepares TSB-37-A for ballot as an ANSI standard. TR-30.3/95-07-057 (S. Satchell, Satchell Evaluations) summarizes their hypotheses for discrepancies in V.34 modem performance between TSB-37-A-compliant simulation and the real-world testing. This suggests that the TSB- 37-A model, using a 600 ohm zero point termination with a hybrid balance network and the bridge-tap used (1.5 kilofeet) does not sufficiently characterize the “real-world.” TR-30.3/95-07-058 (S. Satchell, Satchell Evaluations) provides the results of running async performance tests (TSB-38) with a “real” CO (Central Office) configuration and with a 6 kilofoot bridge tap. The results suggest that longer bridge-tap lengths impair modem performance. TR-30.3/95-07-059 (J. Moran, Motorola ISG) provides data on 2-wire port impedance using a dual transformer hybrid. TR-30.3/95-07-061 (R. Fitts, Consultronics) suggests descriptions of transient impairment found on analog data circuits (both analog and digital carriers). It was proposed for use as a starting point to fully define the important transient impairments and as a list of transients for which values of amplitude, duration, and shape be defined for testing modems. TR-30.3/95-07-062, Reference Impedance used in Testing Telephone Network Elements (R. Perez, Bellcore), presents the assumptions made in Bellcore’s proposed generic transmission requirements and objectives applicable to switching systems and digital loop carrier systems. It notes that in the telephone network, it is common practice to assume a 900 ohm impedance on all 2-wire circuits. TR-30.3/95-07-063 (G. Tennyson, Bell South) suggests that the following four areas in the network model in TSB-37-A could be improved: • Specification of 2-wire input impedance • Modeling of digital loop carrier systems • Consideration of the impact of 2-wire tandem offices • Attenuation distortion TR-30.3/95-07-064 (G. Tennyson, BellSouth) presents a graph of the Cumulative Distribution Function of the total lengths of bridge taps (per loop) taken from a sample of 2885 loops in BellSouth. After considerable discussion TR-30.3 decided the following: • BellSouth and some of the other operating companies have found that V.34 modems do not always operate at 28.8k: they often fall back to 26k or 24k. V.34 modems also fall back to 26k and 24k on a large percentage of the network model given in TSB-37-A, thus reflecting the real network. BellSouth has some lines that they can use to

demonstrate these problems. J. Douglass and J. Moran as representatives of Motorola ISG will take a look at the line conditions and report the results back to TR-30.3. • V.34 modems are designed to operate at speeds up to 28.8k. V.34 modems are not guaranteed to operate at 28.8 kbit/s over the majority of PSTN connections. Some V.34 modem designs may never achieve 28.8k over the network. Unlike older type modems (i.e., V.22, V.22bis, V.32, V.32bis), V.34 modems are designed to probe the line and adjust their rate based on the line conditions. With these older types of modems, customers have been able to consistently connect at the highest advertised rate. This is a marketing problem. It is not a problem with TSB- 37-A, the PSTN network or Recommendation V.34. • Nothing at this point suggests that there are any problems with the network model given in TSB-37-A. • Rare and abnormal line conditions that stress the modems are given in the annex of TSB-37-A. Network trouble conditions are not considered to be covered in TSB-37-A. TR-30.3 may want to add some additional stressful line conditions to this annex. • J. Douglass as a representative of Motorola ISG will discuss the committee’s comments with K. Taylor (Data Communications Magazine) in response to the letter that Ameritech sent to K. Taylor. These comments will not be for publication, they will be for information only. • TSB-37-A may be balloted as a revision to TSB-37-A (TSB-37-B) instead of as an ANSI standard. Another alternative may be to simply fold any changes or additions to the network model into the next revision of V.56bis. PN-3509 MAKING TSB-38 INTO AN ANSI S TANDARD TSB-38, Test Procedures for Evaluating 2-wire 4-Kilohertz Voiceband Duplex Modems, is a TSB, and does not have the status of a standard. This project prepares TSB-38 for ballot as an ANSI standard. S. Satchell (Satchell Evaluations), Editor, reviewed TR-30.3/95-07-056, Draft 3 of PN-3509 with editor’s notes. After some discussion, TR-30.3 decided to send out Draft 3 of PN-3509 for committee letter ballot as a revision to TSB-38. TR-30.3 decided not to send PN-3509 out for ANSI letter ballot because it makes many references to TSB- 37-A and there are unresolved issues concerning the status of TSB-37-A. PN-3251 CELLULAR NETWORK TRANSMISSION MODEL FOR EVALUATING MODEM PERFORMANCE AND PN-3507 TEST PROCEDURE FOR EVALUATION OF CELLULAR MODEMS PERFORMANCE TR-30.3/95-02-009© (M. Dolan, Celeritas) suggests a table of characteristics to be used in evaluating modem performance when used in a circuit switched cellular environment. TR-30.3/95-05-049 (S. Satchell, Satchell Evaluations) contains the report for the May 17, 1995, ad hoc meeting and a draft of PN-3251, “Cellular Network Transmission Model for Evaluating Modem Operability.” TR-30.3/95-07-065 (A. Sacuta, Ericsson) contains an RF budget for a typical cellular link. This shows the possible forward path loss as 165.8 dB and reverse path loss as 164.5 dB. TR-30.3/95-07-066 (A. Sacuta, Ericsson) contains the cellular network reference model from the ballot version of IS-41-C (Cellular Radio Telecommunications Intersystem Operations). After considerable discussion, TR-30.3 decided the following: • S. Satchell (Satchell Evaluations) will act as editor. • TR-30.2/95-05-049 will be used as the starting point for the document. Appropriate sections from TR- 30.3/95-02-009© will be added to TR-30.2/95-05-049. • The scope of the document will be to define the network model for an analog cellular modem connected to a PSTN modem. • The model will be based on impairments that stress the modem rather than likelihood of occurrence of particular impairments. • The model will define the types of cellular impairments and the level of cellular impairments, but will not define how the impairments will be simulated. • An initial set of terms for the definitions section was listed. • An initial set of impairments that need to be simulated was listed. • The subscriber end (i.e., PC, cellular modem, cable and cellular telephone) of the system needs to be contained in an RF shield environment. The connection to the subscriber cellular telephone should be through a co-axial cable. Jack Douglass

TR-30.4, DTE-DCE PROTOCOLS

LIAISON REPORTS

No formal liaison statements were submitted to TR-30.4 at this meeting. However, TR-30.4/95-05-071, a liaison to Study Group 14 from the June 1995 LBC meeting in Boston, was considered during the discussions on the DTE/DCE interface protocols under PN-3319 (Voice/Data Multiplexing the DCEs - DTE-DCE Interface Operations). J. Decuir (Microsoft) reported that TR-29.2 work relating to TR-30.4 is winding down and that liaison with TR-29.2 will no longer be needed. He also reported that he was resigning as chair of TR-29.2. PN-2989 EXTENSIONS TO SERIAL ASYNCHRONOUS DIALING AND CONTROL

Since it had been discussed in detail at the last meeting, D. Rife (Hayes) only very briefly presented TR-30.4/95-05- 37R2, the latest version of his proposed modem test commands (AT+T). He then presented TR-30.4/95-07-060, a proposal for modem approval test commands that resulted from the discussions on TR-30.4/95-05-37R1 at the last meeting. This proposal was discussed, and it was proposed to change the H1 command to +TH. An alternative suggestion was to add a ‘send nothing’ parameter to the +TSEND command. It was agreed that, in order to simplify homologation, there should be a manufacturer-specific strap to enable/disable all of the modem approval test commands, since some administrations do not want users to have access to these sorts of commands. D. Rife indicated that he would produce a revised document reflecting the proposals discussed. J. Decuir (Microsoft) presented TR-30.4/95-05-044R1, revised draft Annex A/V.25ter on V.8 DCE control. L. Brown (V.8bis Rapporteur) proposed the addition of two more code points in Table A: enable V.8 - no tone sent, and enable V.8 - send CT (modem calling tone). This was agreed to by TR-30.4. L. Brown also raised the issue of command precedence when both V.8 and V.8bis are supported in a DCE. Since commands for V.8bis DCE control have not yet been formulated, no action was taken on this point. Concerning the open issue on page 1 of TR-30.4/95-05-044R1, it was agreed to leave the decoding of JM (Joint Menu) by the DCE as optional for now. In order to reach closure on these issues, it was agreed to send out a partial PN-2989 committee letter ballot including the material from documents TR-30.4/95-05-037R2 and TR-30.4/95-05-044R1. Resolution on draft Annex A/V.25ter is needed by the September meeting of TR-30.4 in order to have a U.S. position for the October Study Group 14 Working Party 1 meeting, and to allow it to be sent to the SG 8 Rapporteur meeting in September in Palo Alto, California. TR-30.4/95-07-061 is a letter from S. Satchell (Satchell Evaluations) to TR-30.4 regarding modems that may not be complying with TIA-602 timing requirements. Specifically, he reports problems with some modems not accepting an ATA command 100 ms after issuing a RING indicator. The current wording in section 5.3 of TIA-602 is DTE- centric instead of DCE-centric. TR-30.4 asked S. Satchell to prepare a contribution on the subject. The next day, S. Satchell presented TR-30.4/95-07-078, a proposal to have a new AT command to indicate how fast the DCE can accept commands. However, after some discussion, TR-30.4 decided not to proceed with the proposal. PN-3319 VOICE/DATA MULTIPLEXING THE DCES - DTE-DCE I NTERFACE OPERATIONS

B. O’Mahony (PN-3319 editor) chaired the session for the PN-3319 discussions. J. Decuir (PN-3319 acting secretary) presented TR-30.4/95-07-052, the report of the joint ad hoc meeting on DTE/DCE protocols for SAVD (Simultaneous or Alternating Voice Data) and multimedia devices (see report in this issue of CSR-T). At the ad hoc meeting, three interface needs were identified: • A low level interface, where most of the functionality is in the DTE, the modem being responsible primarily for modulation, as addressed in TR-30.4/95-07-054 (J. Decuir, V.25ter Editor) and TR-30.4/95-07-057 (B. O’Mahony, Intel). • A mid level interface, where both the DTE and DCE handle some of the media input/output, as addressed in TR- 30.4/95-07-053 (J. Decuir, Microsoft). • A high level interface, where most of the functionality is in the DCE with a “dataport” to the DTE, as addressed in draft Rec. H.324. TR-30.4 agreed to send a liaison to T1A1 concerning a potential missing specification for the “dataport.” It suggests allowing control and configuration from a DTE in the case of H.324 being implemented entirely in a device separate from the DTE. J. Decuir (Microsoft) then presented TR-30.4/95-07-054, which supersedes TR-30.4/95-07-073 and TR-30.4/95- 07-074 (ad hoc documents, DTE/DCE/95-07-010 [J. Decuir, V.25ter Editor] and DTE/DCE/95-07-010R1),

July-August 1995 Vol. 6.5 Copyright © CSR 1995 45 COMMUNICATIONS STANDARDS REVIEW - TELECOMMUNICATIONS respectively. TR-30.4/95-07-054 proposes an Annex B to V.25ter to address the low level interface identified above. It defines a DTE-DCE multiplexing protocol for synchronous data access modes and is similar to Fax Class 1 but is full duplex. It uses the escape character for in-band commands and indications, as in T.31. The scope of the proposal has six components: • Map the DCE-DCE bit streams to DTE-DCE asynchronous-framed octet streams. • Provide for DCE support of HDLC octet framing with flags and flag transparency. • Provide for DCE support of CRC (Cyclic Redundancy Code) generation and checking. • Provide for control and indication of V.34 rate renegotiation and carrier retrain. • Provide means to select and indicate this mode of operation. • Provide for DTE control of DCE flow control thresholds. TR-30.4/95-07-057R1 (B. O’Mahony, Intel) is an edited version of TR-30.4/95-07-054 . During the discussion, L. Staples (Data Race) raised the issue of mark idle mode, used in SNA (IBM’s Synchronous Network Architecture), 3270, 5250, etc., where a single closing flag is followed by mark idle. There may be a timing issue. The mark idle mode must be set before opening a frame. It was agreed to try to allow for the proprietary protocols without specifically naming them. E. Newman (Compaq) suggested we also need to differentiate NRZ (Non-Return to Zero) and NRZI (Non-Return to Zero on Ones) modes in HDLC. It was also agreed that non-integral octet HDLC support would be for further study. TR-30.4 agreed that TR-30.4/95-07-057R1 would be used as the baseline text for this work. B. O’Mahony agreed to take over the draft and will update and distribute it before the next meeting. Open issues include: • Should this multiplex protocol be part of V.25ter, V.ib (in-band control), or something else? • Should the in-band commands be based on Annex B/T.32 (), TIA-617 (), or ISO-3309? TR-30.4/95-07-053 is J. Decuir’s (Microsoft) first draft proposal for the mid-level DTE-DCE interface identified above. This interface needs at least the following components: • A control model for the DCE • Semantics and syntax for DCE control • A DTE-DCE multiplexer TR-30.4/95-07-053 only addresses the multiplexer component. It omits DTE-DCE error control. The document identifies the following requirements: • Be very simple, trade more bandwidth for simplicity. • Multiplex 5 channels: DTE-DCE control, system (H.245) control, data, audio, and video. • Include per channel flow control for the system channel and the three media channels. • Build on “draft Annex B/V.25ter” so that carrier control pieces can be reused. TR-30.4/95-07-053 proposes to: • Add 5 code points to “draft Annex B/V.25ter” for channel delimiters. • Add 1 code point for an “idle channel” delimiter. • Add 4 pairs of code points for the individual channel flow controls. • Add a +S V.25ter command to select this operating mode. It was agreed that TR-30.4/95-07-057R1 and TR-30.4/95-07-053 would be further modified and submitted as multi-company papers to the upcoming SG 14 SAVD Rapporteur meeting, August 7-12, 1995. On behalf of the ad hoc participants on the subject, C. Garthwaite (Microsoft) briefly presented TR-30.4/95-07- 056. It addresses easier transitions between services that employ common modulation (e.g., changing modes between SAVD and T.30 Annex C facsimile over a V.34 connection), and references LBC-95-218 on the same topic. It was agreed that the DTE interface ramifications need further study. J. Decuir indicated that he would bring a paper to the next meeting. TR-30.4/95-07-058 (J. Decuir, Microsoft) proposes changes to TIA-617 to allow 8 bit in-band commands. Proposed modifications to TIA-617 would be backward compatible with the existing version. There was a general discussion on when to use a vs. escape character and how to split the commands in TR-30.5/95-07- 057R1 between them. It was agreed that this proposal needed further work. Contributions were invited. During the discussion, J. Decuir pointed out an error in Table 5 of TIA-617, which will be fixed before it is published. PN-3131 ASYNCHRONOUS VOICE DCE CONTROL, REVISION OF PN-2986

This work was previously transferred from TR-29.2 to TR-30.4. TR-30.4/95-07-055 (C. Garthwaite, PN-3131 Editor) discusses how to reorganize the work on PN-3131. The document categorizes parts of PN-3131 as either: 1. Voice or data components of the SAVD suite

2. Call control and call progress 3. Call modality, capability exchange and selection 4. DTE-DCE interface As a result, parts of the current PN-3131 may be considered under PN-2989, V.25ter, V.8bis, and the V.6x SAVD suite. Category 1 items above would become part of the IS-101 (Asynchronous Voice DCE Control) standard and/or a V.6x Recommendation. There was a discussion on whether the category 2 items should be taken internationally or be a separate U.S. standard (possibly part of PN-2989). It was pointed out that category 2 is of general utility, not just for voice modems. It was also pointed out that there is a T1E1 document on distinctive ringing etc., that is out for ANSI letter ballot. It was suggested that if the category 3 issues could be completed quickly, Annex A/V.25ter would fit better there, but there may be insufficient time to meet SG 8’s requirements. Category 4 relates to V.25ter extensions. It was proposed and agreed that IS-101 should also be reaffirmed for a second time by September 1995. C. Sneed (previous editor of IS-101) suggested that categories 1 and 2 are the heart of IS-101, while 3 and 4 are peripheral. Since TR-30.4 agreed to reaffirm IS-101 for one more year, it was agreed to ballot PN-2989 (not the current committee ballot discussed above) when ready with all of the category 2 issues (maintaining compatibility with IS-101). It was agreed that in the subsequent process of converting IS-101 to a standard, to reference the PN-2989 standard commands but mandate backward compatibility with their +V equivalents. Concerning the voice coder for the PN-3131 standard, it was suggested that G.dsvd might be a good choice as the default coder. TR-30.4/95-07-062 (A. Heinke, Radish)offers editorial corrections to the latest draft of PN-3131 (TR-30.4/95-07- 070). TR-30.4 accepted the corrections. A. Heinke then presented TR-30.4/95-07-063 concerning the use of the manufacturer specific event codes in IS- 101. It was not clear from IS-101 whether these codes were to be assigned to specific manufacturers or whether they were available for use by any manufacturer. It was clarified that the latter was the case. A. Heinke then withdrew TR- 30.4/95-07-063 and TR-30.4 agreed to clarify the use of these codes. The AT+FMI command will be used to first identify the manufacturer, after which any of the five codes can be used by that manufacturer. During the discussion on PN-3131, a small error was discovered in the latest draft (TR-30.4/95-07-070). In Table 10, on page 30, event numbers 63, 48, 49, 50, and 51 should be changed to event numbers 64, 65, 66, 67, and 68. Finally, A. Heinke mentioned the shielding of DTMF signaling (section 7.6 of TR-30.4/95-07-070), and asked about shielding of other signals such as call/answer tones. She indicated that Radish would bring a proposal on this to the next meeting. PN-3499 WIRELESS MODEM CONTROL

TR-30.4/95-07-45R2 (J. Decuir, Editor) is the third draft of PN-3499, an ANSI standard based on PCCA (Portable Computer Communications Association) STD-101. There was no time at this meeting to discuss it. It will be sent out for ANSI letter ballot. The plan is to resolve ballot comments at the November TR-30 meeting. PN-3463 MODEM COMMAND SET BIBLIOGRAPHY

TR-30.4/95-07-059 (J. Decuir, Editor) is a status report on the TSB for modem commands. The first output of the work was the V.25ter supplement. However, there is more work to be done. The supplement omits information text and result codes, and it omits in-band signals. Material to be included in the next version of the V.25ter supplement include: • SAVD DCE control • Voice DCE control • V.8 and V.8bis control • More wireless and cellular work (PN-3499) • More facsimile work (Annex B/T.31 and Annex C/T.32) It was agreed to delay the forwarding of this work to ITU-T until more of the undefined work has been completed. The goal is to propose an update to the supplement at the March 1996 SG 14 meeting. If stable drafts are ready for the Munich SG 14 WP 1 meeting in October, an interim update could be brought to that meeting. OTHER HIGHLIGHTS

It was agreed to forward the following documents to TR-30:

• The report of the DTE-DCE interface ad hoc meeting (TR-30.4/95-07-052) to be sent to the SAVD Rapporteur meeting in Portland. • The PCCA draft for ANSI letter ballot (TR-30.4/95-07-045R2). • A liaison to T1A1 on “dataport” control (TR-30.4/95-07-079). • A liaison to the SAVD Rapporteur meeting in Portland on dataport control (TR-30.4/95-07-080). Les Brown, Motorola-Codex

TR-30 MEETING ROSTER, JULY 10 – 14, 1995, IRVINE CA Dick Brandt, dB Consulting Chair, TR-30 Les Brown, Motorola Codex Chair, TR-30.1 Fred Lucas, General Datacomm Chair, TR-30.2 Jack Douglass, UDS-Motorola Chair, TR-30.3 Jay Bain, UDS-Motorola Chair, TR-30.4 3Com Primary Access Sandeep Aqarwa Intel Chris Hanson 3Com Primary Access John Rosenlof Intel Barry O’Mahony 3Com Primary Access Richard Williams JRC International Lawrence Brisebois Adtran Kevin Schneider Microsoft Joe Decuir Air Communications Kent Kernahan Microsoft Charlie Garthwaite Air Communications Kevin Surace Motorola ISG Jay Bain AMP, Inc. George Lawrence Motorola ISG Art Barabell AT&T Dick Brandt Motorola ISG Les Brown AT&T Gordon Bremer Motorola ISG Don Cantwell AT&T Bell Garudt Motorola ISG Jack Douglass AT&T John Scarmalis Motorola ISG Jack Moran AT&T Larry Smith Motorola ISG Jerry Viviano AT&T R.K. Smith National Semiconductor John Goldie AT&T Microelectronics Bill Garvis Penril Data Com Dick Stuart AT&T Paradyne Domenick Ginex Phylon Venkat Ganesan AT&T Paradyne William Girton Pinpoint Comm. Jim Price Bellcore Ricardo Perez Radish Comm. Ann Heinke BellSouth Gary Tennyson Rockwell Bernard Debbash Berk-Tek, Inc. Tom Debic Rockwell Darrell Dederich Celeritas Michael Dolan Rockwell Mike Gauer Celeritas Glenn Ray Rockwell Glen Griffith Cirrus Logic David Kiro Rockwell Qui Huang Cisco Systems Steve Turadek Rockwell Omar Khwaja Cognisys, Inc. Raymond Lutz Rockwell Craig Mellon Compaq Computers Edward Newman Satchell Evaluations Stephen Satchell Consultronics Louis Chenier Stac Electronics Robert Lutz Data Race Les Staples TAS Michael Pellegrini dB Consulting (for AT&T) Dick Brandt TAS Dave Tarver Digital Equipment Corp. Remi Lisee Telebit Systems Ken Jones DSP Group Sandra Huang Texas Instruments Kevin Gingerich Ericsson Al Sacuta US Robotics Shishir Bommireooi General DataComm Fred Lucas US Robotics Andy Norrell Hayes David Rife US Robotics/Megahertz Wayne Park Henderson Coms. Labs Warren Henderson Verifone Jackson Ma IBM Ali Sadri Ziff Davis Labs Jim Wolf

ACRONYM GLOSSARY

ACTE Approvals Committee for Terminal Equipment ANSI American National Standards Institute API Application Programming Interface ASVD Analog SVD ATM Asynchronous Transfer Mode BTC ETSI Business Telecommunications Committee C&I Commands and Indications CC Communication Capabilities CENELEC Commission Europeenne de Normalisation Electrotechnique CF Communication Functions CIF Common Intermediate Format CNG Comfort Noise Generator CRC Cyclic Redundancy Code CTR Common Technical Requirements DAVIC Digital Audio-Visual Council DCE Data Circuit Terminating Equipment DSP Digital Signal Processing DSS1 Digital Subscriber Signaling 1 DSVD Digital SVD DTE Data Terminal Equipment DTMF Dual Tone Multi Frequency DTR Data Terminal Ready EEA European Economic Area EEC European Economic Community EIA Electronic Industry Association EMC Electromagnetic Compatibility EMI Electromagnetic Intereference ETR ETSI Technical Reports ETS European Telecommunications Standard (ETSI) ETSI European Telecom. Standards Institute EWOS European Workshop on Open Systems FCC Federal Communications Commission (U.S.) FEC Forward Error Control FM Frequency Modulation FTP File Transfer Protocol GA General Assembly (ETSI) GOB Group of Blocks (H.261, H.263) GSM Global System for Mobile communications (formerly Groupe Speciale Mobile) GSTN General Switched Telephone Network (e.g., PSTN) HDLC High Level Data Link Control HF Human Factors HLC Higher Layer Compatibility HLTF High Level Task Force HSSI High Speed Serial Interface IDL Interface Design Language I-ETS Interim ETS IEC International Electrotechnical Comm. IMTC International Multimedia Teleconferencing Consortium IN/B Intelligent Network/Broadband INTRA Coding mode in H.263 in which no prediction is applied I/O Input/Output IPR Intellectual Property Rights ISDN Integrated Services Digital Network ISI Inter Symbol Interference ISO International Standards Organization ISP International Standardized Profile ITU International Telecommunications Union LAN Local Area Network LBC Low Bit rate Coder LC Logic Channel LVDS Low Voltage Differential Signaling MHS X.400 Message Handling System

MIPS Million Instructions Per Second MMCF Multimedia Communications Forum MUX Multiplexer NA Network Aspects ODA Open Document Architecture ONP Open Network Provision PAC Program Advisory Committee PB Personal Base PC Personal Computer PCCA Portable Computer Communications Association PCI Programmable Communications Interface PCMCIA Personal Computer Memory Card International Association PE Public Inquiry PNE Production of Norms in Europe PSTN Public Switched Telephone Network PT Project Team QCIF Quarter CIF RF Radio Frequency SAVD Simultaneous or Alternating Voice Data SCF System Communication Function SDF System Directory Function SDL Specification and Description Language SG Study Group (ITU, CCITT) SNR Signal to Noise Ratio STC Sub Technical Committee (ETSI) SVD Simultaneous Voice Data TA Technical Assembly TBR Technical Basis for Regulation (ETSI standard) TC Technical Committee TCR-TR Technical Committee Report-Technical Report TD Temporary Document (ITU, CCITT) TDMA Time Division Multiple Access TE Terminal Equipment (ETSI Committee) TIA Telecommunications Industry Association TR Technical Report TRAC Technical Regulations Application Committee TS Technical Specification TSB Telecommunication Systems Bulletin (TIA) TSS Test Suite Specification TSSC Technical Standards Subcommittee (TIA) VAD Voice Activity Detector VSELP Vector Sum Excited Linear Predictive Coding WG Working Group XID eXchange IDentification

1995 MEETING SCHEDULES AS OF AUGUST 9. 1995 Subject to Change without Notice TR-45.2 Aug 14 - 18 Toronto, Ont TR-29 Oct 16 - 19 San Diego, CA TR-45.5 Aug 14 - 18 Vancouver, BC TR-45.2 Oct 16 - 20 Tampa, FL TR-46.1 int. Aug 15 - 17 Toronto, Ont TR-45.3 Oct 16 - 20 Toronto, Ont TR-45 NAG Aug 17 Toronto, Ont TR-45.5 Oct 16 - 20 Seattle, WA TR-45.1 Aug 21 - 23 Vancouver, BC SG 15 LBC Oct 17 - 20 Darmstadt, FRG T1E1 Aug 21 - 25 --- G.dsvd Rapp Oct 23 - 27 Europe TR-45.4 Aug 21 - 25 Vancouver, BC TR-41.6 Oct 23 - 27 --- TR-46 Aug 28-Sep 1 Monterey, CA TR-45.4 Oct 30-Nov 3 Chicago, IL TR-45.3.6.1 int Aug 29 Durham, NC JTC(Air) Nov 6 - 10 --- TR-45.2 int Aug 30 - 31 Chicago, IL T1P1 Nov 6 - 10 --- TR-45 Sep 4 Denver, CO ITU-T SG 15 Nov 13 - 24 Geneva G.dsvd Rapp Sep 11 - 15 Annapolis, MD T1E1 Nov 13 - 17 Orlando, FL JTC(Air) Sep 11 - 15 --- TR-30 Nov 13 - 17 Orlando, FL TR-30 Sep 11 - 15 Portland, OR TR-45.2 Nov 13 - 17 CO Springs, CO TR-45.3 Sep 11 - 15 Quebec City, TR-45.3 Nov 13 - 17 Orlando, FL Que TR-45.5 Nov 13 - 17 CO Springs, CO TR-45.5 Sep 11 - 15 Cape Cod, MA ITU-R SG 8A Nov 22–Dec 1 Geneva G.dsvd Rapp Sep 14 - 15 Bethesda, MD ETSI TE Nov 27 - Dec 1 Antwerp Belg. SG8 Rapp Sep 18 - 22 Palo Alto, CA TR-45 Nov 27 Dallas, TX T1S1 Sep 18 - 22 New Jersey area TR-46 Nov 28-Dec 1 San Antonio, TR-41 Sep 18 - 22 Vancouver, BC TX TR-45.2 Sep 18 - 22 San Antonio, T1S1 Dec 4 - 8 --- TX TR-41 Dec 4 - 8 Los Angeles, SG 15 Rapp Sep 25 - 29 VA, U.S.A. CA TR-45.4 Sep 25 - 29 Orlando, FL TR-45.4 Dec 4 - 8 Orlando, FL Q3, 8, 15/8 Oct Kyoto, Japan T1A1 Dec 11 - 15 San Jose, CA Rapp TR-45.2 Dec 11 - 15 Maui, HI Q10/8 Oct 2 - 6 Paris, France TR-45.3 Dec 11 - 15 Maui, HI TR-46 Oct 2 - 6 Orlando, FL TR-45.5 Dec 11 - 15 San Diego, CA WP 14/1 Oct 9 - 14 Munich

The next issue of Communications Standards Review – Telecommunications (Vol. 6 #6) is scheduled for September 1995.

Communications Standards Review –Telecommunications (ISSN 1081-4655) is published 6 - 8 times per year, within days after the latest, related standards meetings. Editor: Elaine J. Baskin, Ph.D. Technical Editor: Ken Krechmer. Copyright © 1995, Communications Standards Review. All rights reserved. Copying of individual articles for distribution within an organization is permitted. Subscriptions: $595.00 per year worldwide. Discounts for additional subscriptions are available. Submit articles for consideration to: Communications Standards Review, 757 Greer Road, Palo Alto, CA 94303-3024 U.S.A. Tel: +1-415-856-9018. Fax: +1-415-856-6591. e-mail: [email protected] or [email protected]. 16905