CSR Volume 3 #3, April 1992

COMMUNICATIONS STANDARDS REVIEW

Volume 3, Number 3 April, 1992

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-45.3 Digital Cellular Standards, February 3 - 7, 1992, East Rutherford, NJ...... 2 TR-45.3.A Ad Hoc Authentication Group...... 2 TR-45.3.1 — User Needs and Services...... 2 TR-45.3.2 — Dual-Mode Standards...... 2 TR-45.3.2.5 — Circuit Data Services...... 3 TR-45.3.2.6 — Authentication Performance...... 4 TR-45.3.2.8 — Packet Data Services...... 4 TR-45.3.3 — Digital Standards...... 4 TR-45.3.3.2 — Half-Rate Voice Coder...... 4 TR-45.3.4 — System Performance...... 5 TR-45.3 Plenary Roster, February 3-7, East Rutherford, NJ...... 6 TR-30 Data Transmission Systems & Equipment, March 9 - 12, 1992, Norcross, GA...... 7 Update on V.fast Test Suite...... 7 TR-30.2, Data Transmission...... 7 TR-30.3 Data Communication Network Interfaces...... 8 TR-30.4, DTE-DCE Protocols...... 10 TR-30 Roster, March 9 - 12, 1992, Norcross, GA...... 12 TR-41, Telephone Terminals, March 9-13, 1992, St. Augustine, FL...... 13 TR-41.EC, Ad Hoc Management...... 13 TR-41.1 PBX And ISDN Terminating Equipment...... 13 TR-41.1.1 Business Communication Systems — Transmission ...... 15 TR-41.1.3 ETSI/JTC1 Harmonization...... 16 TR-41.3, Telephones and ISDN Terminals...... 17 TR-41.4 NCTE Standards...... 19 TR-41.7 Safety and Environmental Considerations ...... 20 TR-41.7.1 North American Telecommunication Equipment Safety (TES)...... 21 TR-41.9 Regulatory Considerations ...... 21 TR-41 Partial Roster, March 9 - 13, 1992, St. Augustine, FL...... 23 Voice Related Extensions to the AT Command Set: A meeting of Vendors, 17 Ma. 1992, San Jose, CA ...... 24 Roster of the Voice Related Extensions to the AT Command Set, 17 Mar. 1992, San Jose, CA ...... 27 TR-29.2 DTE/DCE Voice/Facsimile Digital Interface, March 25 - 26, 1992, Costa Mesa, CA...... 27 Roster of TR-29.2, March 25 - 26, 1992, Costa Mesa, CA ...... 33 TR-45.4 Microcell/PCS, March 31 - April 2, 1992, Irving, TX ...... 33 Liaisons...... 33 FPLMTS Presentation...... 33 Ad Hoc Committee Reports...... 33 Work Plan ...... 34 TR-45.4 Structure...... 35 TR-45.4 Plenary Roster, March 31 - April 2, 1992, Irving, TX ...... 36 Voice Related Extensions to the AT Command Set: A meeting of Vendors, Apr. 7, 1992, San Jose, CA...... 37 Roster of the Voice Related Extensions to the AT Command Set, Apri.7, 1992, San Jose, CA...... 38 Acronym Glossary...... 38 1992 & 1993 Meeting Schedules as of April 20...... 40

TR-45.3/92.02.07.05 is a memo from CTIA informing the wireless industry of the CTIA’s upcoming technology fora. The fora will examine wideband/spread-spectrum options for cellular. The first forum will be held 17 and 18 March 92 in Chicago, IL.

TR-45.3/92.02.07.07 notifies that a Joint Experts Meeting on Transmission Planning will be held 09 to 12 March 1992 in Richardson, TX.

At its next meeting, TR-45.3 expects to receive a final draft of the CTIA’s User Performance Requirements for a Digital Control Channel.

TR-45.3.A AD HOC AUTHENTICATION GROUP

IS-54-B A PPENDIX A

TR-45.3.A completed IS-54-B Appendix A, Authentication, Message Encryption, Voice Privacy Mask Generation, Shared Secret Data Generation, A-Key Verification, and Test Data (TR-45.3.A/92.02.04.02 as amended). TIA will control distribution of the appendix as required by the International Traffic in Arms Regulations (ITAR). Having fulfilled its charter, TR-45.3.A was dissolved. A new group may be set up under TR-45 to deal with authentication for EIA/TIA-553, the analog compatibility standard.

TR-45.3.1 — USER NEEDS AND SERVICES

TR-45.3.1 develops the Cellular Mobile Telephone Service Descriptions (CMTSD) — high-level descriptions used by other working groups to guide standards development.

TR-45.3.1 prepared a new mandate and presented it to TR-45.3 as TR-45.3/92.02.07.02. “TR-45.3.1’s objective is to agree with the CTIA on detailed descriptions of all services and features to be supported in North American Digital Cellular Standards and to provide the detailed descriptions to the other groups within TR-45. The descriptions will be of the form of bearer services, teleservices, teleservices facilities, and supplementary services wherever appropriate.” TR-45.3 had some problems with the proposal, e.g., expanding the working group’s scope to encompass all of TR-45 and having the working group act as a liaison with CTIA. It therefore deferred the contribution until its next meeting.

TR-45.3.2 — DUAL-MODE STANDARDS

IS-54-B D UAL-MODE MS-BS COMPATIBILITY (PN-2759)

At its last meeting, TR-45.3 approved IS-54-B for publication; however at this meeting, TR-45.3.2 identified some editorial problems. As a result, the editor will make the following corrections before sending the document to TIA. TR-45.3.2/92.02.06.02, Concerns found with revision B of IS-54 (Ericsson), identifies five corrections to IS-54-B. TR-45.3.2 adopted four.

Correction 1 — §2.6.5.2 Confirm Initial Traffic Channel Add a timeout to prevent the mobile station from locking up on a digital traffic channel: If the mobile station does not receive a physical layer control message within 5 s, it shall turn off its transmitter and return to the Serving- System Determination Task. TR-45.3.2/92.02.07.02 contains the adopted text.

Correction 2 — §2.7.3.1.3.3.1 Info Element Field Description For the Signal information element field, add the word “on” to the last ON cycle for the following cadences: Short- Short-Short-Short and PBX Short-Short-Short-Short. The word is missing from the adopted text.

Correction 3 — §2.6.5.3.1 Waiting for Order

Add a timeout to terminate the Shared Secret Data (SSD) update process if the base station does not respond to a challenge: If the mobile station fails to receive the Base Station Challenge Order Confirmation within 5 seconds of when the Base Station Challenge Order was transmitted, terminate the SSD update process.

Correction 4 — §2.7.2.1 Reverse Analog Voice Channel Messages The order qualifier in the Page Response message should not be set to zero. ORDQ may take other values.

TR-45.3/92.02.07.03, a letter from P. Nurse (Chairman) to N. Adawi (Ameritech), responds to the eight issues raised by Ameritech in their rejection ballot for IS-54-B. The letter states that if the chairman does not receive correspondence to the contrary by 06 March 92, TR-45.3 will assume Ameritech’s objections have been satisfactorily addressed and will publish PN-2759 as IS-54-B.

TR-45.3.2/92.02.06.03 (SW Bell) identifies that the Flash with Info and Alert with Info messages in IS-54-B differ from IS-54-A. As a result, IS-54-B mobile stations will not be able to use Three-Way Calling and Calling Number Presentation in IS-54-A systems. The contribution recommends that a TSB be issued to warn operators and manufacturers. W. Müller (Ericsson) will propose text for a TSB .

ADDITIONAL ISSUES

TR-45.3.2/92.02.07.03 (Hughes) proposes that the SACCH be removed from the half rate channel structure and that the bits be allocated to the half-rate voice codec. It also proposes that a voice activity detector be added to control use of the FACCH, i.e., FACCH would only be accessed during silent intervals in speech. The contribution was deferred pending review of three issues associated with the proposal: the impact on speech quality, the impact on signaling bandwidth, and the impact on future revisions of IS-54. TR-45.3.2 adopted a two-step process to deal with the issues. First, TR-45.3.3, TR-45.3.2.3, and TR-45.3.2.4 will accept and review contributions at their March meetings. Then, in April, a joint meeting of TR-45.3.2 and TR-45.3.3 will decide what to do, documenting their decisions in a report to TR-45.3.

J. Marinho (AT&T) resigned as TR-45.3.2 chairman. P. Treventi (AT&T) was nominated for the position.

TR-45.3.2.5 — CIRCUIT DATA SERVICES

TR-45.3.2.5 develops recommendations for circuit-switched data services, with a focus on Async Data Service and Group-3 Fax Service. The recommendations will be incorporated in the next revision of IS-54.

ASYNC DATA SERVICE

TR-45.3.2.5 completed TR-45.3.2/92.02.06.05, the Stage-1 (user perspective) service description for Async Data Service, and presented the description to TR-45.3.2. TR-45.3 will forward the description to TR-45.2, TR-30, and CTIA for their review and comment. TR-45.3.2.5 hopes to review comments, in the form of written proposals to change baseline text, at their 23 March 92 meeting.

Because users may wish to exercise different tradeoffs in handling the data-hostile air interface, TR-45.3.2.5 defined two types of Async Data Service: Type I and Type II.

• Type I is non-transparent. It is characterized by variable transit delay, variable throughput, and a controlled error rate. The error rate is comparable to PSTN connections. In simple terms, this service trades transit delay and throughput for a low error rate.

• Type II is transparent. It is characterized by constant transit delay, constant throughput, and a variable error rate. In simple terms, this service trades error rate for constant transit delay and constant throughput.

The Stage-1 description is in the form of a pseudo users manual. It describes how to provision, invoke, and operate the service. For mobile stations with EIA/TIA-232-E interfaces, the user’s data-terminal equipment basically sees a wireless modem. Extensions to the industry-standard AT command set allow access to cellular-specific features. Users can access the same applications they previously used with conventional modems. One interesting cellular feature allows the user’s mobile station to automatically answer data calls in data mode and route voice calls to the

April, 1992 Vol. 3.3 Copyright © CSR 1992 3 COMMUNICATIONS STANDARDS REVIEW user’s handset. Unlike the PSTN, and similar to the ISDN, the cellular network knows whether the call is voice or data. This information can then be passed to the mobile station during call setup.

GROUP-3 FAX SERVICE

While TR-30, TR-45.2, TR-45.3, and CTIA review the Async Data Service Description, TR-45.3.2.5 will devote its efforts to finishing the Stage-1 service description for Group-3 Fax.

CHANNEL AND PROTOCOL ARCHITECTURES

TR-45.3.2.5 presented its working paper, TR-45.3.2/92.02.06.04, to TR-45.3.2. It describes high-level channel structures and protocol architectures at five network reference points. Two reference points are data interfaces at the mobile station. Three reference points are interfaces between the cellular network and three other networks: the PSTN, the ISDN, and the Packet-Switched Public Data Network (PSPDN). TR-45.3 will forward the description to TR-45.2 and TR-30 for their review and comment.

TR-45.3.2.6 — AUTHENTICATION PERFORMANCE

TR-45.3.2.6 develops procedures for verifying that mobile stations comply with the authentication and voice-privacy requirements of IS-54-B.

TR-45.3.2.6/92.02.05.04 (Sony) proposes methods for verifying that mobile stations properly execute the authentication algorithms. The methods are suitable for a field-service environment — they require no access to secret information in the test equipment or mobile station. In discussing the contribution, TR-45.3.2.6 determined that A-key verification and SSD (Shared Secret Data) generation cannot be field tested. TR-45.3.2.6 deferred the contribution pending results of two assignments: the task force will determine if some of the information is subject to the International Traffic in Arms Regulations (ITAR) and it will prepare procedures for testing voice privacy and message encryption.

TR-45.3.2.8 — PACKET DATA SERVICES

TR-45.3.2.8 develops recommendations for packet data services. The recommendations will be incorporated in the next revision of IS-54.

TR-45.3.2.8 continued with the definition of its charter. The task force solicits contributions in which packet-mode services should be a priority for development of Stage-1 service descriptions. The CTIA’s User Performance Requirements for a Digital Control Channel should contain some direction in this area.

TR-45.3.3 — DIGITAL STANDARDS

TR-45.3.3 develops the all-digital cellular standards. TR-45.3.3 deferred any significant discussion of the digital control channel until it receives the CTIA’s User Performance Requirements for a Digital Control Channel.

TR-45.3.3.2 — HALF-RATE VOICE CODER

TR-45.3.3.2 develops standards for half-rate voice codecs.

PROJECT PLAN

TR-45.3.3.2/92.02.06.03 (Chairman) lists objectives, describes related standards activities, describes the subjective test, lists key milestones, and shows a project chart. The technology assessment should be complete by April 1992. Standards are expected mid 1993.

TECHNOLOGY ASSESSMENT

TR-45.3.3.2 received 12 half-rate codecs for the technology assessment. Processed speech material was delivered directly to representatives of the test laboratories. In April, the task force will forward to TR-45.3.3 the results of the assessment, together with a recommendation of whether or not to proceed with standardization.

VOICE ACTIVITY DETECTION

TR-45.3.3.2/92.02.06.06 (Hughes) provides a C-language computer simulation of the voice activity detector (VAD) used in GSM. The contribution triggered discussion on the trade-offs between voice and signaling requirements. Some members suggested that the design criteria to support digital speech interpolation would differ from the design criteria to maximize voice quality. The former criteria might result in an on off switched VAD; the latter might result in a variable-rate speech codec. The task force concluded that since TR-45.3 had not excluded variable-rate codecs, the task force is open to proposals.

TR-45.3.4 — S YSTEM PERFORMANCE

TR-45.3.4 looks at systems issues related to capacity, quality, and complexity. It makes recommendations that lead to development or amendment of cellular standards.

CAPACITY OF DSI AND HALF-RATE CODECS

TR-45.3.4/92.02.06.03 (Hughes) and TR-45.3.4/92.02.06.04 (Fujitsu) present capacity-modeling results for digital speech interpolation (DSI) used in conjunction with half-rate voice coding. TR-45.3.4/92.02.06.03 accounts for control-channel requirements as a function of voice activity factor (VAF); TR-45.3.4/92.02.06.04 does not. As a result, TR-45.3.4/92.02.06.04 mildly understates capacity at low VAFs and mildly overstates capacity at high VAFs. TR-45.3.4/92.02.06.03 shows a minimum capacity enhancement over EIA/TIA-553 of 10.9 times. This occurs at a VAF of 45% under interference-limited conditions. Maximum capacity enhancement is 19.3 times. This occurs at a VAF of 35% under trunk-limited conditions.

PERFORMANCE METRICS FOR RLPS

TR-45.3.4/92.02.06.06 (GTE) proposes performance metrics that may be applied to connection-oriented and packet- oriented data services. After discussing the contribution, TR-45.3.4 agreed that it would be impractical to develop a general model for evaluating the performance of Radio Link Protocols (RLPs). As a result, the working group adopted the following five-step plan:

1. TR-45.3.4 will list and define metrics.

2. TR-45.3.4 will describe the conditions under which the metrics should be applied, e.g., RF channel model.

3. TR-45.3.4 will forward the metrics and conditions to TR-45.3.2.5, TR-45.3.2.8, and TR-45.3.3.

4. Guided by the metrics and conditions, organizations will submit channel-structure and protocol proposals to TR- 45.3.2.5, TR-45.3.2.8, and TR-45.3.3.

5. TR-45.3.4 will develop models to evaluate the proposals.

TR-45.3.4 adopted June 1992 as the target date for Item 3. Two organizations volunteered to prepare contributions dealing with Items 1 and 2. For next time, J. Ketchum (GTE) will submit an expanded list of metrics, including proposed definitions, and S. Kay (HNS) will propose an RF channel model.

Condensed from Cellular TechNotes, February, 1992. Next Generation Information Consulting, Alan Sacuta, V: 403-239-4089, F: 403-239-4306.

TR-45.3 PLENARY ROSTER, FEBRUARY 3-7, EAST RUTHERFORD, NJ

Peter Nurse, HNS Chair TR-45.3

ALPS Masa Ushie Asahi Chemical Rachel Strauss AT&T Cheryl Blum AT&T John Marinho AT&T Phil A. Treventi Bell Atlantic M.S. Michael Haberman BellSouth Cellular Thomas E. Richter CPSR Marc Rotenberg Ericsson François Sawyer Ericsson Radio Sys Barry Kratz Ericsson Walter Müller GE Corp R&D Howard L. Lester GTE Les Owens HNS Stan Kay IMM Gil LaVean McCaw Cellular David Holmes Motorola Bob Picha Motorola Louis Finkelstein Motorola Tom Auchter NEC America Edward Ornelas NEC America Stephen S. Jones Nokia Kimmo Myllymaki NovAtel Allan Angus NovAtel Rock Shih NTI Gary Boray NTI Wing Lo NYNEX Erkin Çubukçu OKI Reed Fisher OKI Ryo Kamazaki Panasonic Sam McConoughey Sharp Prem Sood SNET Cellular George Liberopoulos Sony Simon Mizikovsky SW Bell Tech Res. Terry Watts Toshiba John Gabor

The CSR Library

Copies of documents listed in boldface type can be ordered from Communications Standards Review, where not prohibited by copyright. We have a large library of standards work in process and can help you locate other information you may need.

TR-30.1, Modems, did not meet.

UPDATE ON V.FAST TEST SUITE

L. Smith (AT&T) and J Moran (Motorola) have completed a revision of the V.fast Test Suite as agreed at the Rapporteur's Meeting in Florida (Feb. 1992). This revision includes all parts of the test suite, whether modified or not, and, therefore, obsoletes all previous versions. When ordering from CSR, please request Rev. V.fast Test Suite.

TR-30.2, DATA TRANSMISSION

ISO 26- PIN CONNECTOR

It was reported that the 26 pin connector (Alternative A for EIA/TIA-232-E and EIA/TIA-530-A) had passed the CD (Committee Draft) ballot in ISO. At the January meeting of ISO/IEC JTC1 WG 3, this project was forwarded for DIS Ballot. Assuming no negative inputs, an international standard for this connector could be approved this summer.

EIA/TIA-530-A

Chairman Lucas announced that "camera ready" copy for ANSI/TIA/EIA-530-A has been forwarded to TIA for final internal approval and publication. This will bring the U.S. standard into alignment with ISO 2110 Amendment 1, approved in 1991. The exact date on which ANSI/TIA/EIA-530-A will be available for purchase is not yet known.

HIGH SPEED SERIAL INTERFACE (HSSI)

The major work item for this meeting of TR-30.2 was the continued effort to complete the work on the High Speed Serial Interface standard (PN-2796) and its companion Electrical Characteristics standard (PN-2795). Draft 3 (TR- 30.2/92-01-005R1) of PN-2796, High Speed Serial Interface For Data Terminal Equipment and Data Circuit- terminating Equipment, was reviewed by the committee. This draft incorporates the various changes which were agreed to by the TR-30.2 committee at its January 17, 1992 meeting. No substantive changes were suggested for the next draft, although a number of editorial and clarification changes will be incorporated in Draft 4.

Progress was made by the TR-30.2 ad hoc committee on electrical characteristics. This group provided a draft of PN-2795 (TR-30.2/92-03-011) which had been reviewed during the week. The draft presented has now been extensively revised and will be made available to the members for the next meeting.

At the January 1992 meeting, a possible problem had been identified concerning a single source of components to implement the electrical characteristics. Fortunately, the ad hoc committee found that the standard can be written such that there are many sources of devices which will comply and interoperate. This was very good news since this problem had cast a shadow over the work during the January meeting.

One area in which the ad hoc committee has been concerned is to determine the consequence of plugging a SCSI II interface into the HSSI. There has been international concern expressed regarding this possibility since both interfaces use the same physical connector. If it is found that physical harm would occur with this interconnection, some preventive method will need to be incorporated into the HSSI work.

With the progress that has been made on both the PN-2795 and PN2796 standards, it is the goal of TR-30.2 to move them forward to industry ballot after the July, 1992, meeting.

REVISIONS TO CCITT V.24

As a result of the input to the January meeting regarding the inclusion of Loopbacks A and B (from HSSI) in CCITT V.24, a contribution (TR-30.2/92-03-012) was approved for CCITT Study Group XVII. TR-30.2/92-03-012 recommends two areas of change to V.24. First is the inclusion of the loopbacks as discussed at the January meeting

of TR-30.2. Second is a modification of the definitions and use of the three Common Return circuits, 102, 102a and 102b. The use of these three circuits, when both V.10 and V.11 electrical characteristics are included in the same interface, could cause ground loop problems. In order to eliminate this potential problem, minor changes to the wording of these circuit definitions have been proposed.

It was recognized that this was an opportune time to review V.24 in its entirety, and to recommend any other changes which might be beneficial. The only area which was discovered to be somewhat out of date was in the subsections of 4.6 which discuss the application of the timing circuits 113, 114 and 115. These sections contain a requirement that DCEs and DTEs shall provide timing on these circuits as long as the equipment is powered. It is inappropriate for CCITT to place requirements on DTEs. In addition, as is the case in applications of HSSI, timing on interchange circuits may be withheld for various reasons. As a result, recommended changes to section 4.6 were added to the contribution. This will be discussed at the June meeting of CCITT Study Group XVII.

Fred Lucas

TR-30.3 DATA COMMUNICATION NETWORK INTERFACES

TR-30.3/92-03-029 is the 1992 Document Register.

J. Douglass (UDS, Chairman TR-30.3) distributed a letter (TR-30.3/92-03-036) thanking D. Moon (GDC) for his many contributions to the committee.

TR-30.3/92-03-028 is a letter from P. Bennett announcing TIA's ANSI accreditation.

J. Douglass reviewed the E-Mail letter that he sent to D. Brandt (dB Consulting, Chair TR-30) showing the present TR-30.3 project status (TR-30.3/92-03-025). The committee decided the following concerning the status of the projects:

• PN-1372 - Leave this project open until we are able to contact R. Provost (BellCore) about whether technical information concerning the function of TEK 5 and TEK 6 (loopback indicate) on the JM8 (8 pin modular jack for connection of analog voiceband private line services) and JM25X jacks can be added to the T1E1 document on connectors. If this information cannot be added to the T1E1 document, we will revise TSB 18 (Mechanical/Functional Characteristics of the Interface between DCEs and Voiceband Analog Channels) under this project number.

• PN-1922 - This project is active and covers the ongoing liaison activities with T1A1 (formerly T1Q1). Since D. Moon (GDC) will not be available to conduct this liaison, J. Douglass will set up a paper liaison with T1A1.

• PN-2277 - This project will remain active so that TSB 37 (Switched Network Transmission Simulator for Evaluating Modem Performance) and PN-2826 (TSB 38) can be combined into one document at a future date. It is not known at this time whether the TSB s will be used to expand Section 5 of EIA/TIA 496-A or whether they will become a new standard. Some committee members felt that EIA/TIA 496-A should be revised, because it goes beyond the requirements of Part 68. J. Douglass will discuss this with C. Berestecky (Chair, TR-41.9).

• PN-2825 - This project (TSB 37) is completed.

• PN-2826 - The committee is just beginning to work on this project. The Application Notes on Modem Test Methodology (TSB 38) are expected to be completed by December, 1992.

FCC LIAISON

J. Douglass distributed TR-30.3/92-03-023 and TR-30.3/92-03-024, FCC Billboard for January and February 1992 for information purposes.

IEEE P743 LIAISON

TR-30.3/92-03-027A through TR-30.3/92-03-027E, documents concerning activities in IEEE P743 committee (Measuring Analog Transmission Parameters for Telecommunications), were distributed for information purposes.

T1Q1 LIAISON

D. Moon sent a T1Q1 Liaison Report (TR-30.3/92-03-026). IEEE-820 Standard for telephone loops is being reaffirmed by IEEE since there is no other standard to replace it at this time. A response to the TR-30.3 request for standardized switched access was discussed but T1Q1.1 views were mixed. Initially, T1Q1.1 (to become T1A1) will focus on specifying special access lines (leased lines).

TR-41.9 LIAISON

The committee drafted a letter (TR-30.3/92-03-031) to C. Berestecky (AT&T, Chairman of TR-41.9) supporting the Automatic Dialing Requirements. This support is given based on the assumption that computer controlled autodiallers are exempt from the requirements.

SG XVII L IAISON

TR-30.3/92-03-030A through TR-30.3/92-03-030H (documents from the February 1992 V.fast Rapporteurs meeting (see CSR 3:2), TR-30.3/92-03-033, and TR-30.3/92-03-034, Proposed V.Fast Test Suite Revision, were distributed for information purposes

TSB 37

TSB 37, Public Switched Telephone Network Transmission Simulation for Evaluating Modem Performance, is now available through Global Engineering Documents, 1-800-854-7179 (or +1-714-261-1455). The cost of the document is $41

TSB 38, APPLICATION NOTES ON MODEM TEST METHODOLOGY (PN-2826)

TR-30.3/91-06032 (Standard Project Authorization for PN-2826), TR-30.3/91-10077 (draft of Telecommunication Systems Bulletin PN-2826), and TR-30.3/91-08067 (Outline for PN-2826) were distributed for reference purposes.

D. Rife (Hayes) submitted TR-30.3/92-03-032 which discusses issues related to testing the throughput of data- compressing modems. He proposed that: throughput be defined as the rate at which a file is delivered to the receiving DTE; and that throughput be tested using standard test files whose compression characteristics have been computed (standard files should be made available). While discussing this document, the committee had the following comments: 1. How should files and program for throughput testing be made available? J. Douglass called P. Bennett (TIA) about this question. P. Bennett said that disks could be sold with the standard or that they could be made available through some public forum as long as TIA didn't incur any cost. 2. The purpose of the tests should defined. 3. Tests should reflect user environment. 4. Potential test limitations should be explained. 5. Offer solutions to problems that the users may encounter while running the tests (programs, files, etc.). 6. Tests should be as short as possible but long enough to be accurate. 7. One section of the document should cover use of a protocol on top of a protocol. 8. Define whether the test files should be sent once or multiple times. 9. Warn user that details should be reported when something goes wrong. 10. Is it possible to incorporate throughput tests into the testers? 11. Explain characteristic of the tests, not how to implement the tests (i.e., use 386 PC). 12. Provide examples of scripts that may be used to set up typical modems. 13. Provide warning to users that TSB doesn't encompass all tests to ensure the modem complies with everything.

The remaining time was spent drafting TR-30.3/92-03-035, a preliminary draft of TSB 38. The committee established the following goals concerning TSB 38:

1. Definitions should be short and concise. Elaborate within test descriptions. 2. Define and understand audience - Worldwide test houses and corporate customers with a wide variation of knowledge. 3. Presentation of initial contributions at May 11, 1992 meeting. 4. Draft all sections by July 26, 1992 meeting. 5. Rebuttal contributions by October 12, 1992 meeting. 6. Ballot by December 14 meeting. 7. Procedures should tightly specify each test.

The following committee members agreed to draft sections of TSB 38:

Section Committee Member 4.2 D. Rife (Hayes) 4.3 Open 4.4 Open 4.5 S. Satchell (Satchell Evaluations) 4.6 S. Moore (TAS) 4.7 L. Brown (Motorola Codex) and S. Moore (TAS) Appendix A open Appendix B N. Knudsen (Consultronics) Appendix C J. Douglass (UDS), L. Owens (PTT), and N. Knudsen (Consultronics) Appendix D Each person contributing to Section 4. Appendix E open Appendix F L. Brown (Motorola Codex)

The committee members agreed to have their section(s) submitted to S. Satchell (Satchell Evaluations) by April 20, 1992. This will permit S. Satchell to compile them and submit a revised draft of TSB 38 at the May meeting.

Jack Douglass, UDS-Motorola

TR-30.4, DTE-DCE PROTOCOLS

LIAISON FROM TR-45.3.2.5 (DIGITAL CELLULAR DATA SERVICES)

The chairman, T. Nixon (Hayes), introduced documents TR-30.4/92-03-010 and TR-30.4/92-03-011 from TR- 45.3.2.5 on Digital Cellular Data Services. TR-45.3.2.5 is basing the digital cellular DTE-DCE interface protocol on TIA-602 (PN-2120), and sought TR-30.4's advice on some elements of the work. TR-30.4 reviewed these documents and drafted a reply to TR-45.3.2.5, TR-30.4/92-05-016. TR-30.4 agreed to reserve extended format commands beginning with the letters "+C" for use by TR-45.3.2.5 for cellular data transmission applications.

ASYNCHRONOUS DIALING AND CONTROL (PN-2120)

The chairman presented TR-30.4/92-03-006, the disposition of comments report for SP-2120, and TR-30.4/92-03- 007, the updated version of SP-2120 (to become TIA-602) reflecting the comments which were accepted. He will submit TIA-602 to TIA Technical Standards Subcommittee (TSSC) for review and publication when he receives the new TIA Style Manual, expected shortly.

The chairman restated his desire to submit the final version of TIA-602 to CCITT Study Group XVII, Question 14, to be the new base document for work on "V.at" (the proposed CCITT standard for the AT command set). The committee agreed with this proposal. The chairman then presented TR-30.4/92-03-008, a proposed cover sheet for the contribution. This was approved with a minor wording change; the revised document is TR-30.4/92-03-008R1. (Reporter's note: The chairman subsequently submitted the document to TR-30 and Study Group D for approval; the cover sheet was again modified, by US CCITT Study Group D, and is available as TR-30.4/92-03-008R2. The document has been forwarded to CCITT for distribution as a white document.)

The chairman brought up the need for the USA to comment on proposed new study questions for Study Group XVII. He distributed a copy of the present Question 14 and its annexes, and asked the members to review the documents for discussion at the next meeting. He noted that R. Brandt has already proposed a replacement for Question 14. The chairman indicated his intention to separately mail Question 14 and its annexes and R. Brandt's proposal to the entire TR-30.4 mailing list in advance of the next meeting. This is available as document TR-30.4/92-05-017.

The upcoming TR-29.2 editing meeting on voice commands was discussed. At the request of the members of TR- 30.4, the chairman provided copies of the proposed voice command sets, for information purposes (they were not numbered as TR-30.4 documents, but are available as TR-29.2 documents). The committee noted that one of the papers proposes commands beginning with a variety of letters, including "+C", "+V", "+M", "+R", and "+B". The committee reaffirmed its decision to reserve "+C" for TR-45.3.2.5 work, and agreed to also reserve "+V" for voice work in TR-29.2. The chairman will attend the voice command set editing meeting, and present TR-30.4's position that other command prefixes should not be used without approval of TR-30.4; in particular, "+M" has been reserved for commands related to modems. In general, identifiers for parameters and actions of general application should be assigned in TR-30.4 itself, including such items as master mode control, identification of manufacturer, model, and revision, Caller ID support, and master DTE-DCE data rate control.

The committee agreed to formally request TIA TSSC to affirm TR-30.4's authority to administer extended syntax commands ("+") and to function as the registration authority within TIA (under project PN-2988) for prefix letters. (This was agreed by TIA TSSC at their latest meeting.)

IN-BAND SIGNALLING (PN-2812)

T. Nixon introduced TR-30.4/92-01-003R1, which J. Decuir submitted as editor, taking into account the discussions at the last meeting of TR-30.4. He also presented TR-30.4/92-03-009, which details several questions and concerns on the in-band signalling issue. The committee reviewed both of the documents. Extensive comments on these matters are recorded in the minutes of the meeting (TR-30.4/92-05-015). Some highlights include:

• The committee favors eliminating bitmapped presentation of V.24 circuit states and replacing them with explicit indications of "on" and "off" transitions as command sequences.

• The committee favors using a character other than DLE as the command sequence lead-in, to avoid excessive doubling of characters due to the use of DLE for many additional higher-level command protocols.

• The committee agrees that the standard should specify a protocol that will work in many different environments including LANs and SCSI, and that a special section should be included containing considerations for TIA-602 applications.

• The committee agreed that character formats including parity must be supported, which means that the command sequences must reserve the high-order bit as a parity bit and preserve its value on transparentized characters.

• The committee agreed that when the in-band signalling protocol is being used to indicate V.24 circuit conditions that it should be used at all times including command state in TIA-602 applications. However, it was also suggested that the protocol might be divided into several "subsets" which could be independently enabled and disabled, some of which might be applicable only to on-line data transfer (such as escaping to command state and disconnecting calls).

• The committee feels that while there may be some potential for the protocol to be implemented in standalone devices such as "smart cables," such applications are not a primary goal of the project and compromises will not be made to accommodate such applications.

• The committee agrees that On/Off Hook sequences are desirable, but that Rate Selectors are not.

• The committee agrees that the ability to poll the other device to obtain a complete state update is desirable; the standard will need to specify exactly what information is delivered in response to such a poll.

EXTENDED COMMAND SYNTAX (PN-2988)

The chairman introduced TR-30.4/92-03-012, which contains a proposed title and summary of the project for submission to TIA and ANSI. This was accepted with minor editorial corrections; the updated document is TR- 30.4/92-03-012R1.

EXTENDED DCE FUNCTIONS (PN-2989)

The chairman introduced TR-30.4/92-03-013, which contains a proposed title and summary of the project for submission to TIA and ANSI. This was accepted with minor editorial corrections; the updated document is TR- 30.4/92-03-013R1.

Toby Nixon TR-30 ROSTER, MARCH 9 - 12, 1992, N ORCROSS, GA

Dick Brandt (dB Consulting) Chair, TR-30 Don O'Connor (Racal Datacomm) Chair, TR-30.1 Fred Lucas (General Datacomm) Chair, TR-30.2 Jack Douglass (UDS-Motorola) Chair, TR-30.3 Toby Nixon (Hayes) Chair, TR-30.4 Host: Hayes Microcomputer Corp.

Berk-Tek, Inc. D. Hess Consultronics Neil Knudsen Consultronics Robert Fitts cisco Systems R. P. Brandt (dB Conslt) Data Race Tony Castaldo Defense Info. Sys Ag. Matt Prisutti Digital Equipment M. Ralph Dieter Hayes Dave Rife IBM Corporation Ed Taylor Intel Barry O'Mahoney Motorola-Codex Les Brown National Semicond. John Goldie PTT Larry Owen Satchell Evaluations Stephen Satchell TAS Steve Moore UDS Motorola Jay Bain

Communications Standards Review

regularly covers the following committee meetings:

TIA (USA): TR-29 TR-41 TR-30 TR-45

CCITT: SGVIII SGXVII

TR-41.EC, AD HOC MANAGEMENT

INTERNATIONAL ACTIVITIES

IEC-950. TR-41.EC/92-03-01 is a short report from the UL/CSA/CBEMA/ITAC/TIA/EEMAC Task Force meeting in February. Half of the Task Force members were present at this EC meeting. The Task Force recommended that the Technical Task Group be made up of two subject matter experts from each of the six associations. They decided that their task was not to write a standard, but to define the minimum number of deviations to IEC-950 Second Edition. They have been asked to start with a clean slate with only IEC-950 on it and then add deviations, each with justification, that the Technical Task Group deem necessary. Areas of differences include dielectric testing vs. spacings, overvoltage testing and NEC/CEC requirements. The mission is to develop a bi-national standard based on the second edition of IEC-950, that is acceptable as the UL/CSA equipment safety standard for the Information and Telecommunication Industries. The standard also must not conflict with the NEC and CEC Part 1. Because the Telecommunication Carriers were not directly represented, the working group agreed to recommend C. Tenorio of AT&T, J. Brunssen of Bellcore and T. Killam of Rolm Systems to represent TIA. The first meeting is planned for July. UL will be the oversight agency. The first draft is anticipated after the third meeting in February 1993, with publication in early 1995.

Second Telecommunications Sectorial Meeting. This meeting was attended by standards association representatives of Canada, Mexico and the US. Each country's representatives discussed regulatory and voluntary telecommunication standards operation and associated testing laboratories. Two action items resulted: • A preliminary scope and mission statement will be written by a drafting group and forwarded to the associations represented at the meeting for further refinement. • CCONNTEL will explore the possibility of arranging a tri-national meeting the end of July or the beginning of August to start exploratory work on a single set of harmonized requirements. TR-41.EC/92-03-02 is a short report of the meeting.

DOMESTIC AND TIA ISSUES

TIA/TR-41 Seminar. The Seminar held last week in Orlando was an unqualified success. The Subcommittee gave a vote of thanks to C. Berestecky for the speaker selection and the meeting's success.

Scope Proposal. Discussion of TR-41.EC/92-03-03 from NT on the mission and scope of TR-41 was limited. Full discussions and recommendation on the proposal will be presented at the next meeting. The proposed name, Management Ad hoc Committee or MAC met with general approval. TR-41.EC/92-03-04, the minutes of the first meeting of TR-41 (1976), were distributed for information.

SMDS. No project proposal has been forthcoming. SMDS will be dropped from the EC agenda if nothing is available for next meeting.

LeRoy Baker, Reliance Comm/Tec

TR-41.1 PBX A ND ISDN TERMINATING EQUIPMENT

T1E1 LIAISON

S. Godo, Northern Telecom, called attention to activities in T1E1 and also T1Y1 with possible impact on PBX requirements:

A recommendation was made to T1E1.1 (TR-41.1/92-03-005, TR-41.1/92-03-006) to amend the loop-start/ground- start interface standard with a requirement that, immediately following any Open Switch Interval (OSI), the Customer Interface (CI) shall provide a termination at the Network Interface (NI) with interruptions no longer than 1 msec. This requirement, if adopted, could impact certain PBX line and trunk circuits. Action on this issue is

expected at the next T1E1.1 meeting; thus an early TR-41.1 response was desired. (Reporter Note: OSIs, which momentarily interrupt line power, commonly occur at a change in call state; for certain call states, longer interruptions of the CI termination could result in calls not being completed.)

On the previously reported T1Y1.4 proposal for reducing the minimum loop operating voltage to -40 volts (CSR 3:1), consensus was reached in T1Y1.4 that the -42.5V minimum operating voltage remain in the standard with -40V an optional minimum for new equipment. (Reporter Note: as part of the overall re-alignment in T1 committees, T1Y1.4 will become part of T1E1).

UPDATE/RESTRUCTURE OF TIA-464

TIA-464 Partitioning — Transmission Part: The project description for the transmission part of TIA-464-B (TR- 41.1/92-03-010) was approved. It was agreed by the subcommittee that 464-B will not cover requirements exclusively applicable to PBXs using analog switch technology. For such requirements, TIA-464-A will be referenced. TIA concurred with this position.

TIA-464 Partitioning — Digital Interface Part: A strawman proposal for the digital interface part of TIA-464-B (TR-41.1/92-03-004) outlined the main sections of the part in terms of references to existing standards, specifically T1 standards and CCITT recommendations. The proposed sections include Synchronization, 1.544 Mbit/s Trunk Interfaces, PRA ISDN Trunk Interfaces, and BRA ISDN Line and Trunk Interfaces. A number of the referenced documents were distributed as background to the strawman proposal; they are listed below:

TR-41.1/92-03-

011: CCITT Recommendation G.703 (1991), Physical/Electrical Characteristics of Hierarchical Digital Interfaces 012: Draft Standard T1.216, ISDN Management - Basic Rate Physical Layer 013: Draft Standard T1.102, Digital Hierarchy - Electrical Interfaces 014: Draft Standard T1.217, ISDN Management - Primary Rate Physical Layer 015: Draft Standard T1.218, ISDN Management - Data Link and Network Layers 016: Standard ANSI/T1.408-1990, ISDN Primary Rate - Customer Installation Metallic Interfaces Layer 1 Specification 017: Editorial Report and Baseline Document for Update of T1.4031989, DS1 Customer Installation-to-Network Interface; includes draft revision of T1.403 018: Letter Ballot for T1M1/91-056, Layer 1 In-Service Digital Transmission Performance Monitoring 019: Application Guidelines for Use of the DS1 Extended Superframe Format Data Link, Technical Report, Doc. T1E1.2/90-030R4 020: Integrated Services Digital Network (ISDN) Primary Rate Access Customer Installation Layer 1 Conformance Testing, Draft document NIU/ACT1/91-24R5 As of this time, there are no volunteers to formulate proposals for the other sections (Analog Interface, Signaling) of TIA-464-B. Except for the transmission part, assigned to TR-41.1.1, responsibility for the other parts of TIA-464-B has not been determined.

TIA-464 Revision/Update Listing: The reissue of the TIA-464-B revision and update listing (TR-41.1/92-03-009) is restructured to reflect the proposed partitioning of the TIA-464 PBX standard. It was noted that the current project number, PN-2396, covers the partitioning and the separate parts.

DS-1 Recovery Algorithms: At the last TR-41.1 meeting, an update work item on DS-1 recovery algorithms were put on hold, pending further input. A submission on this topic (TR-41.1/92-03-008) provided such input, based on AT&T Pub 62411. In brief, this pub does not address responses to intermittent Carrier Failure Alarms (CFAs). However, it does specify algorithms for detecting intermittent Loss of Signal (LOS) or Out of Frame (OOF) conditions and for declaring a CFA for either continuous or intermittent LOS or OOF:

The algorithm is based on a rise/decay slope integration process of OOF/LOS counts such that for a continuous LOS or OOF condition, the count threshold for declaring CFA is attained in 2.5 sec. If the signal returns to normal before the threshold is reached, the counter integration process decays at a rate of 1/4 to 1/15 of the rise slope (eventually resetting to zero); however, another failure during the decay period will result in a slope rise at the original rate starting at the count level reached during decay. Thus, intermittent failures at a rate faster than the counter reset time will eventually result in the CFA threshold being reached.

Attendant path cut-through timing: To address the issue of ringing noise to the attendant in the event that ring trip is later than path cut-through, it was agreed at the previous meeting (CSR 3:1) to add a footnote in the appropriate sections as follows: "Since CO ring trip may not occur until up to 200 ms following attendant answer, it is desirable that the PBX provide a means for minimizing or preventing ringing to be heard by the attendant." Further consideration of this issue led to a proposal that the elimination or minimization of ringing noise to the attendant be formulated as a mandatory ("shall") requirement (TR-41.1/92-03-003); following debate it was agreed that the text state that "It is highly desirable that the PBX provide the means to minimize or eliminate any ringing signal that might be heard by the attendant prior to ring trip."

ANSWER SUPERVISION ON DID CALLS

A recent FCC Public Notice requires return of answer supervision to the public network when a call is routed back to the public network with permissible exceptions when a call is unanswered, busy or reorder tone is received from the public network. The implementation of this requires changes in T1.405 (T1E1 developed standard analog voicegrade access using loop reverse battery signalling).

TR-41.1/92-03-007 was provided to TR-41.1 as information by T1E1. This proposes that the events/conditions for which answer supervision on calls routed back to the PSTN from a CPE is returned to the originating end, include the rerouting of the call over an interface that does have return answer capability and answer is returned. This proposal is in recognition that some interfaces now have that capability and that it will be standard procedure on ISDN interfaces.

In the ensuing discussion, the point was made that a PBX, to comply with the FCC ruling on DID Answer Supervision, would nevertheless have to also incorporate one or the other methods for returning answer supervision on incoming calls, i.e., detection of voice energy or a timed interval (20 sec. maximum). This is because, when a PBX is registered, there would be no advance knowledge that connecting trunks with answer capability will be available. However, the capability of a PBX to return answer on a DID trunk in response to receiving answer on a forwarded trunk is considered an inherent requirement of the FCC ruling. The revised proposed text and tables for DID answer requirements in TIA-464 submitted at this meeting (TR-41.1/91-03-012R2) will be further revised to reflect this capability as a PBX requirement.

MAXIMUM AMPLIFICATION BETWEEN PBX PORTS (THROUGH-GAIN TABLE)

Recommendations on the FCC table of maximum amplification between PBX ports (through-gain table) were presented (TR-41.1/92-03-021) with the following points:

• The table of maximum amplification between ports (FCC Rules and Regulations 68.308 (b)(5), also reproduced in TIA-464-A) is needed for PBX tests and registration processes and should be retained.

• Values will be recalculated to be consistent with maximum allowed input and output levels. This will result in certain table cell values to be in conflict with the TIA loss plan for performance. The maximum allowed amplification for these cells will reflect performance requirements. For some ports, this will be effected via re- defining the port maximum input level.

• The table will be expanded to include ISDN trunk ports. Otherwise, no additions will be made to the current table. Presently blank cells will be addressed at a future time.

TR-41.1.1 BUSINESS COMMUNICATION SYSTEMS — TRANSMISSION

With the completion of the ISPBX Loss Plan, approved by ANSI to be published as ANSI/EIA/TIA-464-A-1 Addendum to TIA-464-A (TR41.1.1/92-03-008), this working group has been assigned responsibility for generating the Transmission Part of the next issue of TIA-464; thus, the new working group title. This includes responsibility for items which are identified as related to PBX transmission requirements in the TIA-464 revision/update listing - see the TR-41.1 report, above.

LIAISON REPORTS

M. Kanotz, GTE Services Corporation, reported that "Loss Plan for Evolving Digital Networks" is to be published as ANSI T1.508. With the completion of this document, the T1Q1.1 sub working group on loss and level will be dissolved. T1Q1 itself is to merge with T1Y1 (except for T1Y1.4) and become T1A1. G. Williams (Northern Telecom) has been elected chair of T1A1; P. Cencer (Ameritech) is chair of T1A1.1 which has two SWGs: Voiceband Data and Personal Communications Systems. T1Y1.4 will be merged with T1E1.

TIA-464-B T RANSMISSION PART DOCUMENT

The outline for the transmission part of TIA-464-B (provisionally TIA-464XM) was presented (TR-41.1.1/92-03- 002). The sections correspond to subsections in 4.8 of TIA-464-A with some restructuring; however, each section will be subject to review for current applicability and for verification of quantitative requirements.

INPUT IMPEDANCE REQUIREMENTS

The current TIA requirements for input impedance for an analog line interface are that a return loss of better than 20-26 dB, as a function of frequency, must be achieved against a reference impedance of 600 ohms (TIA 464-A- 1989, Table 16); for a trunk interface, the return loss range is 20-30 dB. (It should be noted that input impedances, per se, are not specified in TIA-464.) Earlier contributions, resubmitted for this meeting as TR-41.1.1/92-03-006 (Mitel) and TR-41.1.1/92-03-007 (Ericsson), propose to modify this return loss range to be equivalent to the ETSI requirements (18 dB mid band, sloping to 14 dB at the edges).

There was significant discussion regarding these proposals for the relaxation of the return loss requirements which define the PBX input impedance. The issues are complex and relate to a number of performance concerns; thus, resolution of the proposal was not achieved. The main discussion points were:

• For lines, relaxation of return loss values while retaining the 600-ohm reference impedance could lead to degraded sidetone performance (TR-41.1.1/92-03-003). Some sets are specifically designed to interface a 600- ohm port.

• A reference impedance for lines which more closely simulates the impedance of cable, such as a three-element network, could lead to improved sidetone performance and allow a relaxation in the return loss criteria for lines (TR-41.1.1/92-03-003).

• Historic 600-ohm port dates back to 2-wire PBXs where the station impedance (approx. 600-ohms on short loops) reflects to trunk port. Digital PBXs provide greater isolation between line and trunk ports, thus allowing more flexibility in impedance design (TR41.1.1/92-03-004).

• Most current processes for ordering and provisioning connecting facilities assume 600-ohm PBX port impedance; also, network-provided equipment, such as digital loop carrier, is designed to interface CPE at the 600-ohm impedance level and may not have other options (TR-41.1.1/92-03-004). Therefore, from a network facility providers viewpoint, it is desirable to retain requirements compatible with 600-ohm trunk port impedance; from the network perspective, any changes need to be specifically proposed and thoroughly analyzed for performance impact.

• The return loss requirements at the Network Interface (NI) should be in agreement with the return loss requirements for access lines as stated in document T1.508 (TR-41.1.1/92-03-005).

TR-41.1.3 ETSI/JTC1 HARMONIZATION

LIAISON REPORTS

Public Digital Synchronization Standard. E. Polansky (AT&T), TR-41.1.3 Chairman, reported on the Edinburgh meeting of the BT2 Synchronization working group. There remain significant discrepancies between the proposed ETSI standard DI/BT2006 and the ANSI/EIA/TIA-594 standard (summarized in TR-41.1.3/92-03002). A major difference concerns slave clock accuracy. TIA-594, following CCITT (Rec. G.811) and T1X1 recommendations, specifies accuracy in terms of stratums (for stratum levels ranging from 1x10-11 to 32x10-6), while BT2006 specifies

16 Vol. 3.3 Copyright © CSR 1992 April, 1992 COMMUNICATIONS STANDARDS REVIEW three classes; working the math to achieve correspondence between stratums and classes is a major concern. The TIA (and CCITT) stratum 1 accuracy is 1 x 10-11; that of ETSI Class 1 is 1 x 10-9. Progress was made towards modifying the latter to 1 x 10-10. Other significant differences exist in the areas of network design philosophy (strategies for supplying clock reference to and within private networks) and free run vs. holdover operation during failure (clock behavior in the event of loss of input timing reference).

PBX Transmission Standards Tracking/Comparison. Documents were sent to the BT2 chairman (J. Horrocks) with a preamble (TR41.1.3/92-03-001). As neither BT2 nor the working group on transmission have met in the interim, there was no response to this mailing, nor any report. The BT2 transmission working group is meeting in London, March 25-27. The next BT2 meeting is May 18-22 in Munich; TIA will be represented by E. Polansky and V. Boersma (Northern Telecom).

JTC1 Activity. Working Group 6 is meeting this week in New Jersey; E. Polansky is editor of the ISO sync standard; however, this standard is not on the agenda for this meeting. There is a need to coordinate this standard with the ETSI and TIA sync standards; however, it is reported that there is not much European interest for this effort.

TIA PARTICIPATION IN ETSI AND DOCUMENT SHARING WITH ETSI

The question was raised as to whether there would be sponsorship for other TIA members, besides E. Polansky, to attend ETSI working party meetings; such attendance would benefit harmonization efforts. The ISPBX Loss Plan was sent to ETSI as well as the transmission comparison papers as noted above; the request was made for other papers suitable for liaison documents.

John Schick, Northern Telecom

TR-41.3, TELEPHONES AND ISDN TERMINALS

LIAISON REPORTS

IEEE-269 (Standard Methods for Measuring Transmission Performance of Analog and Digital Telephone Sets) is being revised.

ANSI/X3S3.48 is now concentrating on testing hearing aids using a fixture rather than actual subjects. They are having difficulties in making repeatable measurements. One member noted that hearing aids with pickup coils originated in Germany; the source is flux loops built into auditoriums. Their telephones had very little flux leakage. In the US, we had telephones with a relatively large flux leakage; German hearing aids and US telephones would thus communicate. The miniaturization of the hearing aid and the addition of electronics in the telephone have had the effect of reducing the coupling between the two.

T1Y1. This working group has been moved into T1E1. At an Ad hoc meeting in February, the battery standard was modified to require that load equipment shall operate down to 42.5 volts and to make 40 volts an objective ("should"). This corresponds to 42 and 44.5 volts respectively at the battery with 2 volts dropped in the wiring, circuit breakers and fuses between the battery to the equipment.

ACTIVE PROJECTS

SP-2431, Addendum to ANSI/EIA-470A, Criteria for ISDN Telephone Compatibility with Hearing Aids. Both the TIA and ANSI comment periods on SP-2431 have expired. TR-41.3/92-03-03 contains the two negative ballots and a ballot with comments. One of the negative ballots was resolved at the last meeting. The resolution of the other negative ballot was accomplished by changing the +3.5 dBPa in 4.1.3 to 0 dBPa. The comments were accepted except that the second "telephone" in the new 3.1.2 was changed to "ISDN" and the respective references to the new sections 3.1.1 and 3.1.2 were added. The Subcommittee agreed to all changes. The Subcommittee then voted to re- ballot SP-2431 because of the change to 4.1.3. This was approved at the Plenary.

PN-2436, 7 kHz Audio Standard. Northern Telecom will generate a draft of PN-2436 for the next meeting if resources are available. It will be based on the Table of Contents in TR-41.3/91-05-06 and the requirements in TR- 41.3/91-12-17 updated to the latest recommendations from the February 92 SG XII meeting.

PN-2892, Revision of ANSI/EIA-470A, Telephone Instruments with Loop Signalling for Voiceband Applications. CSA has agreed to be the editor for PN-2892 using CSA-T510 as the base document. The format of the standard will comply with the TIA requirements. TR-41.3/92-03-04 (Northern Telecom) is a subparagraph-by-subparagraph comparison between EIA-470A and CSA-T510; it is the base from which the harmonized standard will be developed. It presently compares about two thirds of the standards and will be completed as soon as possible. It has been done in an exemplary manner by R. Robinson (NTI). Consensus was reached on the first nine pages at the meeting. The following details the changes agreed to, using CSA-T510 as the base, where e = EIA-470A and c = CSA-T510;

1) add clause 2.1e following 3.4.1c. 2) replace 1.2c with 2.5e. 3) add 2.2e following 1.2.3c. 4) add 2.7e following 1.3.3c. Generate a Canadian version of 2.7e. 5) delete 4.1.4c. 6) replace test loop information in 4.2.1.3.2 (a)c with 4.1.1.2 (2)e. 7) replace Table 3c with Table 4.2e. 8) delete the last sentence in 4.2.1.4.1c. 9) replace 4.2.4.2.2 (a)c with 4.1.2.2 (2)e through 4.1.2. 2 (4)e. 10) replace Table 4c with Table 4.4e.

TR-41.3/92-03-02 (Reliance Comm/Tec) contains portions of T1.401 which need to be incorporated into the standard. The off hook dc characteristics were discussed along with a proposed new Figure 4.10 (from EIA-470A and Figure 25 in CSA-T510). It was noted that the T1.401 requirements were 30 ohms more than those in the proposed Figure 4.10. The 30 ohms represents the resistance allowed for the wiring and any series devices between Customer Premise Equipment (CPE) and the Customer Interface (CI). The figure was accepted after correction and the addition of the data in figure 4.13 (which is contained in Figure 25 of T510) and splitting 4.10 into two figures, one for normal powering and one for power outage.

The Chairman will provide a contribution containing more specific proposals at the next meeting. The first draft of the standard will contain these agreements and will be available at the next meeting. TR-41.3/92-03-09 and TR- 41.3/92-03-10 (both NT) contain changes to CSA-T510 and EIA-470A respectively required to delete references to carbon technology transmitters. They were not discussed except to note that some deletions apply to generic 500 type telephones and may still be needed.

TR-41.3/92-03-05 is a T1E1.1 liaison which describes a problem and proposes a change to T1.401. The problem was the slow response of an off-hook telephone to a network open switching interval (OSI). An OSI is a short period, normally less than 350 msec, in which the network voltage is removed. The change to T1.401 agreed to by the T1E1.1 Working Group is contained in TR-41.3/92-03-06 (attached to TR-41.3/92-03-05) along with a request to TR-41.1 (PBX) and TR-41.3 to review the impact of the change on CPE.

The change to Standard T1.401, Interface Between Carriers and Customer Installations, Analog Voicegrade Switched Access Lines Using Loop-Start and Ground-Start Signaling, allows a 1 msec response time for CPE at the CI following an OSI. This replaces the present requirement which states that the CPE should provide a continuous termination at the CI. The CPE voltage-current (VI) state is expected to be in the acceptable region of the respective figures within the 1 msec period. The members were asked to respond directly to T1E1.1 if these requirements created problems for their products, since their next meeting would precede ours.

TR-41.3/92-03-07, from Thompson Consumer Electronics of Canada, discussed the need for a higher off-hook dc resistance to allow better performance for a line powered speakerphone. It was sent to CSA asking for these requirements to be revisited when the TIA/CSA Standards were harmonized. The TIA-470 and T1.401 Standards allow 400 ohms for the CPE under most conditions. CSA-T510 requires 300 ohms for CPE in all modes. The author of TR-41.3/92-03-07 will provide a contribution to TR-41.3 at the next meeting which makes a specific recommendation. The Chairman volunteered to write a contribution to T1E1.1 requesting that the CPE dc resistance be increased up to 400 ohms in all off-hook states at 20 ma and above and to 444 ohms at 18 ma. Both Ameritech

18 Vol. 3.3 Copyright © CSR 1992 April, 1992 COMMUNICATIONS STANDARDS REVIEW and GTE will be contacted to let them know that we are working on a US/Canada harmonized telephone standard. Both companies have internal standards for telephones. A representative of GTE was present.

TR-41.3/92-03-08 contains a copy of the Ameritech Standard QTR-STD-000100, Voice Band Acoustic Specifications, based on ANSI/EIA-470A optimized to improved performance in high background noise office environments. It was presented by BellCore for information only. A suggestion was made to consider portions of it for an Appendix discussing the application. It was noted that neither EIA-470A nor CSA-T510 contained requirements for sidetone frequency response and that the SOLR (sidetone loudness limit) requirement was only 3 dB. It was informally agreed that both were very complex issues, but that something should be included in an appendix to provide direction to the manufacturer and user.

NEW LEGISLATION

TR-41.3/92-03-01 from R-Tec Systems contains excerpts from Department of Justice 28 CFR (Code of Federal Regulations) Part 36, Nondiscrimination on the Basis of Disability by Public Accommodations and in Commercial Facilities; Final Rule. This defines requirements for telephones used for the hard of hearing. The Subcommittee requested that J. Haynes (TIA), whose committee, Standards Application and Regulation Issues, a Section of UPED, investigate the possibility of TR-41.3 providing test methods for the telephone volume control requirements in Justice Department's ruling. Volume control requirements and test methods are not contained in ANSI/EIA-470A. Also, the Subcommittee requests that any further interpretations of the applicability of the ruling be forwarded to TR-41.3 so that manufacturers of suitable telephones can provide the information to their customers.

LeRoy Baker, Reliance Comm/Tec

TR-41.4 NCTE STANDARDS

TR-41.4/92-03-002, liaison from TR-29.2, requests confirmation that work on DTE/DCE Call Selection problems, which include situations related to fax and answering devices be done in TR-29.2. TR-29.2 calls this the Call Selection Problem. TR-41.4 agreed that this work did not belong to them; written liaison will be sent to TR-29.2.

TR-41.4/91-03-003 is a project proposal to define procedures for establishing a Wide Band Communications Channel by combining multiple switched 56/64 kbit/s channels. This capability has been termed inverse multiplexing in the press. This project proposal was unanimously approved at the TR-41 plenary.

This project will define the methods by which multiple 56/64 kbits circuits will be synchronized and aligned to provide band widths up to 72 x 64 kbits. The group is still in need of an editor. The base document will be submitted from the BONDING Interest Group (Bandwidth on Demand) for consideration as an ANSI Standard.

A related issue (noted in a letter from ACTION Consulting submitted at the New Orleans meeting) when TR-41.4 gets involved in BONDING standards work, is the need for DTE/NCTE interface functions to control the multiple channel requirement. TR-30.4 should be asked to develop enhancements to V.25bis to support these control requirements. The TR-41.4 Chair will write to the TR-30.4 chair .

TR-41.4/92-03-005, submitted by Adtran, suggests that Bellcore's SR-NWT-001953 (Generic Guidelines for ISDN Terminal Equipment on Basic Access Interfaces) be used as the base line text for a standard for terminal equipment connecting to ISDN basic rate to support interface PN-1915 (Terminal Equipment Connecting to ISDN Basic Rate Interface). It was agreed by the group that rather than define everything in the Bellcore SR, they would just address some of the ISDN basic rate terminal definitions and not all of them. Individual standards would be issued as they are completed. An editor is needed for this document.

TR-41.4/92-03-006, a presentation by S. Godo, was an overview of Frame Relay. It was very informative and indicated that there is currently no need for TR-41.4 to standardize Frame Relay NCTE equipment.

TR-41.4/92-03-007 includes two large, hand-marked documents for TIA 547A (Network Channel Terminal Equipment for DS1 Service). The editor, B. Buckley, with the provided input, will produce cleaned up copies at the next meeting.

The SMDS project proposal was discussed. This item will maintain a spot on the agenda, but at this time the SMDS Interest Group is concerned that attempts to write a standard could jeopardize the support and delay the introduction of SMDS. It is their desire to wait to create an ANSI standard. In deference to industry concerns, TR-41.4 will not take action at this time, but will keep the SMDS on the agenda for periodic re-evaluation.

TR-41.4 recommended that TR-41 cancel PN-1916 (PBX ISDN Interface). This was unanimously approved at the TR-41 plenary.

Bill Buckley, Verilink

TR-41.7 SAFETY AND ENVIRONMENTAL CONSIDERATIONS

LIAISON

T1Y1.4 will be T1E1.N at their next meeting in May. The CO Electrical Protection Standard T1.313 is ANSI approved and will have a 1991 date. The T1 letter ballot for Outside Electrical Protection Standard has been completed and they are resolving ballot comments. Electrical Protection of Customer Facilities is in process.

CBEMA-EC is forming a group to focus on education on EC certification issues, primarily how to get products approved. The first meeting is in early April. TIA is also forming a similar committee which is meeting in March.

ELECTROMAGNETIC COMPATIBILITY SEMINAR

D. Heirman of AT&T Bell Labs and Chairman of ANSI C63 Subcommittees 1 and 5 made a presentation to TR-41.7 and TR-41.9. The presentation included a discussion of the recent complaints of interference between licensed (AM) radio transmitters and telecommunication equipment. A meeting was recently held in Los Angeles with the FCC, users and manufacturers to discuss the problems. The FCC would prefer the industry resolve the problems instead to resorting to regulatory means. TR-41.7.3 has been formed for this purpose. Also the organization and functions of C63 were discussed along with activities of interest to TIA. TIA was encouraged to join C63, especially Subcommittee 5, which deals with susceptibility of consumer products including telephone equipment. A copy of the overheads for the C63 presentation was provided (TR-41.7/92-03-unnumbered). Data has been requested on conducted longitudinal signals on telecommunications lines including T1 transmission lines.

ESD PROBLEMS WITH ISDN TERMINALS

T1E1.4 has added a requirement to the Living List of T1.605, ISDN S/T Interface, to use ANSI/EIA/TIA-571 for ESD testing on the TEs. A presentation was made by AT&T Bell Labs to TR-41.7 and TR-41.9 on the potential problems associated with ESD susceptibility of an ISDN Terminal (TE) connected to the S buss along with other terminals. There are failure modes where the terminal receives an ESD spark which can disrupt the operation of the other terminals. Present standards do not specifically address this architecture. The presenter was also concerned that ANSI/EIA/TIA-571, which is proposed by T1E1.4 to specify the ESD requirements for the terminal in the next issue of T1.605, was not aligned with the work going on in IEEE or with IEC 801.2 second edition. No one present indicated having any experience with these new standards although they were aware of them. TR-41.7 indicated they would be revisiting the ESD requirements in TIA-571 and would include consideration of the buss configuration for terminal equipment.

LIGHTNING SURGE REQUIREMENT RECOMMENDATIONS

TR-41.7/92-03-001 (C. Tenorio AT&T) contains recommendations for FCC/DOC testing from TR-41.7 to TR-41.9. The proposal is in response to the consensus reached at the December meeting by TR-41.7. The FCC/DOC issue is the possible open circuit failure of a unit due to the FCC surge with no subsequent network harms compared with the effects of a surge having an energy level which would not cause the unit to become open circuited, but may cause the unit to fail in a manner which will cause harm to the network. The proposal recommends testing with the FCC surge (10x560 µs, 100A), followed by testing for operation and compliance. If the sample was not operational but did not cause network harm, then testing should be done with the CCITT K.21 surge (10x700 µs, 25A) on a fresh or repaired sample. The equipment should remain operational and not cause network harm.

TR-41.7/92-03-004 (D. Moon GDC) contains recommendations to use the CCITT K.21 surge instead of the FCC or DOC surge. The rational is that neither the FCC or DOC surge requirements are adequately specified; most actual lightning surges have energy levels below those of the CCITT surge. Also there are conflicts between some implementation of line interface circuits which, when designed to meet the overvoltage requirements of UL-1459, will fail when subjected to the FCC and DOC surge. In addition, the contribution recommends that the applicant document the equipment failures, if any, after the surge testing and indicate the surge level which it could survive. TR-41.7/92-03-004 contains circuit and waveform details for open circuit voltage and short circuit current which fully characterize the surge generator. TR-41.9 did not made a decision on either recommendation.

METRICATION OF ANSI/EIA/TIA-571

TR-41.7/92-03-003 Attachment 1 contains the recommended English to Metric conversions for FCC Part 68 from TR-41.9 which will be used as a guide for TIA-571 (Environmental Considerations for Telephone Terminals). The Subcommittee followed this with a discussion of the weight versus drop-height requirements in FCC Part 68 and CSA CS-03. The main criteria is the likelihood that a device with an handset attached by a coiled cord would be accidentally pulled off a table. Some of the Subcommittee members agreed to conduct tests to determine how much a base unit would have to weigh to prevent its movement on a smooth surface.

TR-41.7.1 NORTH AMERICAN TELECOMMUNICATION EQUIPMENT SAFETY (TES)

UL-1459-IAC

A UL-1459 Industry Advisory Committee Meeting was held. One of the topics was the UL/CSA/IEC-950 tracking document or "telephone book" which will be used for generating input to the bi-national Task Force.

IEC/TC-74/WG 7 MEETING

TR-41.7.1/92-03-001 is the report of the February meeting. The Restricted Access Locations (RAL), e.g., PBX rooms or Central Offices, were discussed. The possibility of contacting uninterrupted ringing or T1 line voltages on the connector of a vacant card will require a careful wording of the RAL and Service Access Area to ensure a full understanding of the application of these terms. Headway was noted in adding line powered telephones and acoustic shock, and in having ISDN interfaces be considered telecommunication interfaces.

POWER SUPPLIES

Several viewpoints of the battery plant and subsequent requirements for power supplies using the battery plant to generate SELV (less than 42.4 volts) voltages are presented in TR-41.7.1/92-03-003 (BNR). The agencies included UL, CSA, BT and other European PTT's. It was provided for information and consideration for IEC-950.

LeRoy Baker, Reliance Comm/Tec

TR-41.9 REGULATORY CONSIDERATIONS

The TIA Seminar covering Mandatory Product Standards for Canada and the United States was held in Orlando, Florida on March 4 and 5. There were about 130 attendees. The seminar covered electromagnetic compatibility regulations, interconnection regulations, product safety standards and premises wiring regulations for the two countries. It also covered the processes for equipment approval to these regulations and standards. An overview of EC-92 was given. Feedback from the attendees was quite positive.

The updated version of TSB-31, the test standards for Part 68, was available at the seminar.

The 35th FCC Part 68 Industry Meeting was held on March 6, 1992 in Orlando in conjunction with the seminar. Some topics covered in this meeting were the status of the US-Canada-Mexico harmonization, converting Part 68 to metric, radio interference to telephones, ISO 9000, and IEC 950 Safety.

TR-41.9.1 SAFETY, ENVIRONMENTAL AND LEAKAGE

Chairman Mosgrave reported that work was progressing on the harmonized requirements. A strawman leakage current document has been developed. The group believes that harmonization between Part 68 and CS-03 will be a relatively minor task. The group is reviewing a proposal to replace the present FCC Part 68.308 hazardous voltage test with a more benign test. An ad hoc group has been formed to develop a proposal for the definition of ground in the rules. It is apparent that the term "ground" appears in many places in the rules, and the meaning seems to be somewhat different. There was continued discussion concerning the surge testing. A proposal defining the surge wave form was made (see the TR-41.7 report, above, for more information). The final work on the environmental test requirements is awaiting a decision by TAPAC on the drop tests.

TR-41.9.3 METRIC CONVERSION

The working group has completed its work and a letter was sent to the FCC and DOC containing recommended changes to the connector drawings and associated text in Section 68.500 of the FCC Rules. Connector drawings will show all dimensions in millimeters with the English Units in brackets. The conversion factor used was 25.4mm/inch with no rounding of the computed value. This is an absolute conversion so as not to affect compatibility.

TR-41.9.4 SIGNAL POWER HARMONIZATION

Chairman P. Adornato reported that the group was continuing to make progress on the inband signal power requirements. The voice band analog signal power requirements has been tabled. There was discussion concerning Local Area Data Channels (LADC). CS-03 doesn't have any requirements for LADC and a Canadian task force is presently looking at this area. A question has arisen concerning the retention of Message Registration and AIOD requirements in the harmonized rules. The legalities of removing these requirements from Part 68 will be explored. Changes to the through gain table are being discussed with TR-41.1; based on the outcome of that discussion, changes to the table will be proposed for harmonization.

TR-41.9.5 DIGITAL HARMONIZATION

The working group held its first meeting. Chairman T. Gill led the discussion on the differences in the two countries' approach to digital services. It was pointed out that CS-03 does not address subrate digital services, and the pulse templates for 1.544 Mbps are different. CS-03 contains a number of regulations that are considered performance requirements in the U.S. TAPAC is presently reviewing the CS-03 requirements with the intent of revising its requirements.

TR-41.9.6 SIGNALING/SUPERVISION HARMONIZATION

The working group held its first meeting. Chairman M. Hacker led the discussion on the goals of the group. A contribution comparing the CS-03 and Part 68 requirements was reviewed. The group reached consensus on the need for network addressing requirements in the harmonized requirements. The group believes that it is in the best interest of all concerned that the U.S. accept network addressing rules in Part 68.

LIAISON REPORTS

TAPAC Technical Task Force (TTF). Five TAPAC Bulletins were issued in early 1992 regarding the disclosures of BC Tel, AGT and MTS on scheduled services of ISDN/PRA. The scheduled time for service availability vary from 2Q92 to 3Q92. The sixth TAPAC Bulletin of 1992 was issued. The bulletin announced Bell Canada's trial service for Enhanced Call Management in late 1992.

FCC Ad Hoc Administration Group. This group met on March 6, 1992 in Orlando. Concern was raised over FCC Public Notices reaching all those who have need to receive them. It was suggested that associations such as TIA should become more involved in information distribution. This matter will be pursued.

The group is looking at administrative rule changes in Parts 2 and 68. It was suggested that any changes be incorporated with the future TR-41.9 Petition for Part 68 rule changes.

B. von Alven brought the group up to date with the advances made to the experimental electronic filing process for Form 730 applications. His objective is to ultimately have all registration applications filed on disk in order to save space now being taken up by paper filings. Implementation of the Operator Services Order and proper use of RJ jacks were discussed. TR-41.1/TR-41.9 Joint Meeting. Work is under way to review the through-gain table in Part 68 and to bring it and the loss level plan in the TIA 464 standard in line. CBEMA. C. Berestecky reported that CBEMA's Management Committee overlaps in many areas with the TR-41.9 harmonization efforts. CBEMA has formed a new technical committee which is addressing the mandatory EC telecom product standards. C. Berestecky is attempting to coordinate the activity with the TR-41.9/TR-41.7 work. FCC/DOC Actions. The DOC has agreed to limit publishing revisions to CS-03 until the harmonization efforts are complete. USA-Canada-Mexico Harmonization. A joint meeting was held on February 18, 1992 in Toronto. The U.S. and Canada explained their mandatory connection, safety, and EMC regulations and the process for equipment approval. Mexico stated their position on a trilateral Telecom Standard development as follows: • Establish a permanent consultant committee to promote and coordinate harmonization activities. • Establish reciprocal approval procedures for telecom equipment to harmonized standards based on international standards. • Establish a laboratory accreditation system that allows reciprocal recognition of test results. • Continue network-to-network connection as in the past, based on negotiated agreements between carriers. A joint meeting with the Mexican standards people has been tentatively set for the week of July 27, 1992. The objective of the meeting would be the harmonization of the Mexican standards with the TR-41.9 efforts to produce a North American standard. The group was concerned that more work needs to be done before such a meeting should be scheduled. C. Berestecky will continue to work this issue and will report back at the next meeting. C. L. Berestecky, AT&T

TR-41 PARTIAL ROSTER, MARCH 9 - 13, 1992, S T. AUGUSTINE, FL Vic Boersma (Northern Telecom) Chair, TR-41 Richard Frank (Rolm Systems) Chair, TR-41.1 LeRoy Baker (Reliance Comm/Tec) Chair, TR-41.3 Dave Curtis (Bellcore) Chair, TR-41.4 Tom Killam (Rolm Corporation) Chair, TR-41.7 Paul Kish (Northern Telecom) Chair, TR-41.8.1 Chuck Berestecky (AT&T) Chair, TR-41.9 Adtran Roger Cain Motorola, UDS Steve Turner Alberta Gov't Tel Don Cheeseman Northern Telecom John Schick AT&T Ed Polansky Northern Telecom Mel Hacker AT&T Terry Schmalzried Northern Telecom Pierre Adornato B. C. Telephone Terry Gill Northern Telecom Ron Robinson Bell Atlantic Trone Bishop Northern Telecom Severin Godo Bell Canada Efrain Guevara Redcom Labs, Inc. Bruce Littlefield Bell South Gary Tennyson Rolm Systems Joel Adams Bellcore Bob Koester Rolm Systems Tailey Tung Bellcore Rolyn Callahan Thompson Cons. Elec. Terry Eckert Certelecom Labs Inc. David Dulmage TIA Hal Berge Comdial Corp. John Green UDS Motorola Steve Turner CSA Ross Cotton Univ. of Waterloo Dennis Rittenhouse (for GTE Telephone Op's Mike Kanotz CSA) Mitel Doug Oddy Verilink Bill Buckley Mitel Roger Britt

A group of software, hardware and semiconductor vendors has coalesced to create extensions to the AT command set to support voice related capabilities. While this group is not a formal standards making body, the wide interest in voice-related functions prompts CSR to include this report. The participants agreed to have the report of this meeting published in CSR.

Meeting Agenda:

• Determine which common AT commands and S registers should be used. • Compare IVP version 1.08 with Rockwell version 1.1 (TR-29.2/92-08)

Four papers were presented:

IVP version 1.08 (revision of TR-29.2/92-09) Rockwell version 1.1 (TR-29.2/92-08) Comparison of TR-29.2/92-08 and TR-29.2/92-09, from D. Luong of DEC (TR-29.2/92-23) PN-2986 Project statement (TR-29.2/92-18)

AT COMMAND SET ISSUES

In a previous meeting, C.C. Su (The Complete PC) had proposed that the committee study the use of the following AT commands and S registers (see below for S registers):

ATA Answer ATD Dial ATH Hangup ATO Reconnect ATI Identification ATE Command echo ATV Verbose mode ATZ Reset AT&F Factory default AT&W Save settings AT&Z

There is consensus that the ATD, ATA and ATH commands should be included, as in TIA-602, except that the DCE doesn't make a modem connection.

The ATO command is redundant with the #VRS command, and should be ignored.

The ATI command is not standardized anywhere, and is redundant with the #VMR command; ATI should be ignored.

The ATV command and ATE command are important. However, the committee thinks that there should be voice- specific commands to control them, so that modem (or fax) software doesn't conflict with voice software. C.C. Su was requested to propose syntax and semantics for such a command. There is a consensus that the modem should default to echo off. As in Class 2, non-verbose mode means no leading and no trailing .

The ATQ command will be ignored.

The ATL and ATM command should be supported, but the issue will be left to the TR-29.2 editing meeting (see the following report).

The committee doesn't see the point of specifying non-volatile parameter storage, since we don't believe software will count on it unless it is mandated. In the likely multi-use DCE (voice/FAX/data), the software can't count on the state of the DCE. Therefore, we see no point in implementing AT&F (redundant with #VIP), AT&W or AT&Z.

ATZ is important. The IVP committee thinks that the ATZ command should be used the same way as in Class 2, as a global reset, and take the DCE back to data mode if implemented.

S REGISTERS

S0 auto-answer ring count S1 current ring count S3 line terminator S4 line feed S5 back space S6 wait before blind dial S7 wait for answer S8 delay for comma dial modifier S9 carrier detect response time S10 carrier loss response time S11 DTMF duration

S0 and S1 are for auto-answering. The IVP committee thinks that auto-answering is not desired for voice operation, since the software has to be ready anyway. S0 and S1 are to be ignored for voice mode.

S3 and S4 specify the characters used for command line framing and response framing. The committee would hard- wire these to the traditional and characters, as in Class 1 and Class 2, and ignore S3 and S4.

S5 is for back-space and command line editing. The committee considers command line editing to be irrelevant for voice operation, and would ignore S5.

S6, S7, S8 and S11 are common dialing functions, and may be used for voice operation.

S9 and S10 are redundant with the #VSI and #VTH commands, and should be ignored for voice operation.

FEATURES FOUND ONLY IN IVP PROPOSAL, TR-29.2/92-09R

The committee is still interested in the features found in the IVP proposal:

Automatic level control enable/disable Activity timer Halt/pause Resume command Status reporting event mask Hooks for manufacturer specific commands

FEATURES FOUND ONLY IN THE ROCKWELL PROPOSAL, TR-29.2/92-08

• Caller ID The committee agrees that Caller ID reporting should be supported, and agreed with the three distinct semantics proposed by Rockwell: no reports, formatted reports, unformatted reports. However, the preference is for a separate voice syntax and parameter, so that different software for FAX, voice and data doesn't interfere.

• Packet Protocol The committee agrees that the packet protocol (SP-2724/TIA- 605) should be supported, and mandated, with default ON. Again, the syntax should be separate for voice, so that voice and FAX software don't interfere (e.g. +VPP).

• Distinctive Ring reporting The committee agrees that distinctive ring detection and reporting should be supported.

• Ringback detect conditioning The committee does not see the need for the +VRA and +VRN parameters if the IVP status reporting methods are used. C. C. Su considers these parameters dangerous.

• Buffer size The committee considers the buffer size parameters useful as read-only registers.

• Buffer skid The committee considers the buffer skid parameter essential, particularly to specify skid in the DCE-to-DTE direction.

FEATURES FOUND IN BOTH PROPOSALS

• Mode control The Rockwell paper specifies one command with different values for data, Class 1 FAX, Class 2 FAX and voice operation. The committee consensus is that the different modes should be distinct. There should be separate parameters for the FAX and Voice states, and a state diagram developed to specify state transitions.

• Event Reporting The committee agrees with Rockwell's list of incoming events to report, but would add Ringback and "Bong" tones.

• Voice Sampling Controls The committee disagrees with Rockwell's semantics for control of sampling rate and sample method; it would prefer to separate them.

• Tone generation The IVP committee prefers a separate command for generating single and multiple tones rather than using the ATD command.

• ID reports The committee decided that the requirement in the Class 2 specification that ID fields should not contain OK or 0 is also required in the IVP, to allow software to locate the end of the fields.

• Reset commands The committee thinks that a global ATZ command and a voice-specific #VIP command should be supported.

• Gain and Volume setting The committee thinks that the gain setting and volume control commands need a reference level, e.g., dBm instead of dB. The same comment applies to the silence detection features.

• Record/Playback control The IVP committee objects to having external events automatically terminate record or playback. They think external events should be reported by the DCE, and halt of play or record decided by the DTE.

FEATURES FOUND IN NEITHER PROPOSAL

J. Decuir proposed that provisions be made to turn off XON/XOFF flow control and use Class 2 style credit flow control, to support UNIX software. The committee agreed.

LIAISON

J. Decuir asked permission to submit this report to the TR-29.2 voice project editing committee hosted by Rockwell on March 25-26. This was granted.

Joe Decuir, Everex

ROSTER OF THE VOICE RELATED EXTENSIONS TO THE AT COMMAND SET, 17 MARCH 1992, SAN JOSE, CA

Sam Weng, The Complete PC (Host/Chairman)

Digicom Steve Chen Digicom Glenn Chu Everex Joe Decuir Rockwell Angelo Stephano The Complete PC C. C. Su Yamaha Jay Virdy

TR-29.2 DTE/DCE VOICE/FACSIMILE DIGITAL INTERFACE MARCH 25 - 26, 1992, COSTA MESA, CA

J. Decuir (Everex) chaired the first day of this meeting; T. Nixon (Hayes) chaired the second day.

Documents distributed:

TR-29.2/92-8R1 The draft revision 1.32 (March 20, 1992) Rockwell Proposal for Voice Mode Extensions for the AT Command Set. TR-29.2/92-18 Proposed Project Statement (PN-2986) source Hayes MicroComputer Products TR-29.2/92-21 Position Paper Concerning Proposed Voice Command Set Changes from Rockwell. TR-29.2/92-22 The IVP Meeting Report from J. Decuir Everex. TR-29.2/92-23 Review of Voice Proposals D. Luong DEC TR-29.2/92-24 Draft list of service requirements T. Nixon Hayes TR-29.2/92-25 Voice Communications Protocol Extensions for the AT Command Set, Sierra Semiconductor

T. Nixon proposed that the committee should first make a "top down" review of the service requirements for the voice mode functionality. There was support in the committee for this approach so long as it could be done in a reasonable time frame.

The committee used the four areas (Voice I/O, Tone I/O, Call Selection, DTE/DCE Other) noted in the project statement as basis to review the necessary service requirements. The following are the positions of the committee on the service requirements, and syntax discussed.

VOICE I/O

• Play back voice is mandatory, record is optional

• A-D/D-A adjustable/selectable (multiple voice sampling algorithms) supported

• Mandate at least one common voice interchange means, e.g., G.721

• Methods are required for detecting and selecting voice encoding

D. Long (Sierra) noted that IVP proposal (TR-29.2/92-09, Rev. 1.08) includes common names of voice sampling. There is support in the committee to have a list of standard compression types, where all compression types are optional and negotiated. K. Snyder (Rockwell) also noted that voice compression should be negotiated, not mandated.

P. Bogosian (Thought Communications) wants to support non-real-time voice stream conversion in the DCE. He desires a PCM (linear) format. C. Sneed (Rockwell) noted that Windows supports 8 bit PCM unsigned format. This format would be mandated when the optional stream format conversion is utilized.

• Silence detection is mandatory, via detect parameter(s). Silence compression and expansion is part of voice compression (e.g., optional).

• Variety of voice I/O devices - PSTN (type of interface, e.g., DID), PBX, local phone, microphone, speaker, etc. I/O jacks - would be supported.

The committee discussed mandatory support of analog interfaces. The IVP proposal supports two required devices and six other optional devices. There is general committee agreement to support single line selection (mandatory); the connection to multiple devices including in parallel would be optional and an ability to query capabilities supported would be optional (syntax to be determined). The committee agreed that playback and record gain control would be optional but the command for such control is required. AGC is optional also.

• Local speaker for monitoring optional

• Record & playback volume control required, linear or AGC (record is input to the DTE, playback is output from the DTE)

• Detect and report events during voice I/O. Table 1, below, lists the events the standard should address.

It was agreed to have a means to interrogate the DCE facilities. There may be a need to have a minimum set of capabilities. In the future, it may be desirable to define sets of service requirements based on applications. P. Bogosian indicated interest in developing examples of such sets.

There is also a need to support a range of DCE events, e.g., buffer overflow. Some of the items on the following list are call progress indications, not events. - Answer tone - Lost data - Voice (high/low confidence) - Play complete

Not connected Connected to Aux Events Playback Record I/O device but idle Ringing M O O O DTMF X ? ? M CNG Fax/Data O ? ? M Telset off-hook - local X O O O Telset off-hook - remote X O O O Silence X X M M SIT tones X O O O Bong tone X O O O Loop current disconnect X O O O Call waiting X O O O TDD 1400/1800 X O O O Call progress X O O O Ringback X O O O CID with ring O O O O CID with call waiting X O O O Unspecified events ? ? ? ? M = mandatory, O= optional, X not applicable, ? not resolved Table 1. Events that the IVP Standard Should Address.

- Bong tone - Dialtone - Busy - Reorder - Ringback - Silence (no sound) - Quiet (end of sound) • Ability of DTE to stop record is mandatory. The ability to stop the playback while holding the contents of the DCEs internal buffer, and restart the playback and not clear the contents of the buffer, is mandated. The ability to start a playback and clear the buffer is also mandated. • Patch through to phone device control handset and line relays. (See additional discussions below.)

TONE I/O

Tone out in the IVP proposal is #VTP and in Rockwell's TR-29.2/92-8R1 is +TNS. The committee agreed that such a capability is desirable during idle. Two tones may be supported (single tone generation is required) but are not required. While recording, a generic tone may also be provided for the purpose of record notification. If necessary, a separate tone would be defined. Frequency and duration of tones (possibly level) is to be defined by a parameter, e.g., f,d,l.

CALL SELECTION Non disruptive mode transitions are needed. This will likely require multiple commands. The DTE can determine the call selection capabilities of the DCE and these capabilities can be enabled by the DTE. How the DCE does call selection is beyond the scope of this project. There is a need to define messages and controls for DCE call selection, not functions for how. It was agreed that the DCE can optionally do call selection and that the DTE can optionally halt or accommodate DCE call selection.

DTE-DCE RELATIONS OTHER (TRANSPARENT MODE, FLOW CONTROL, 3 WIRE INTERFACES) • Existing AT command/response or control sequence in transparent mode.

T. Nixon (Hayes) made the suggestion that, since data rates in voice mode can be high (64kbit/s), an autobaud capability is undesirable in a transparent mode and sequences should be used. He would still support the AT commands for parameter setting. With an available sequence to allow return to AT commands, then AT style operation can be resumed when necessary. In most cases, sequences would not require responses. The problem with this approach occurs when parameter changes are required during operation, such as voice txr, voice rcv, and parameter change.

The committee decided to table the issue of code operation versus the AT command style until the command syntax is defined.

• Packet protocol • Serial rate control without autobaud - yes follow 2388B • Flow control - yes follow 2388B • Autofallback can be supported by inactivity timer • Product ID - committee supports (human or software readable to be determined) • Init (ATZ, AT+VIP, etc.) - committee supports • Buffer size, buffer skid (latency). It was agreed that buffer skid is adjustable and buffer size is detectable. • Playback data underrun • Record data overflow • S Registers

The committee generally supported the related capabilities as defined in Class 2 (PN-2388B) where applicable.

Higher speed interfaces than TIA 232 serial ports (based on 16450/16550/8530) can be utilized for this interface as well. There is interest in supporting a bi-directional parallel port or SCSI port also. This project will not preclude such operation.

The standard should mandate codes for various DCE buffer overrun conditions. A code would be defined for a generic overrun condition. Another possible option is where length is ASCII and indicates the number of voice samples missed. The field must be present.

The standard should mandate a code for unintentional DCE buffer underrun condition. The data stream is only terminated by . In the event of a buffer underrun, the DCE would place silence on the line. The restart after the buffer underrun would require some hysteresis, the details of which is implementation specific.

Caller ID will have the form +VXX. This is an optional function, and is an exception to the scope syntax rule. The scope rule specifies that +V commands are only valid while in voice mode. The optional distinctive ring functionality will comprise a report of the on-off cadence to the DTE. The report form is yet to be determined.

The standard includes optional DID services. The form of the command is to enable/disable the reports. The DCE passes the DID message to the DTE when detected (before first ring).

The committee agreed to the concept of a rotary switch, but could not agree on the competing syntaxes. The issue was tabled.

METHODS FOR DETECTING AND SELECTING VOICE ENCODING METHODS

The sample rate, bits per sample, and compression method identifier commands were combined into a compromise syntax, which follows.

+VSM=, where selects the compression method, and selects the sampling rate. The parameter is an index into a list of possible values.

+VSM? n,s where n is a numeric indicating a compression type, e.g., 0 = G.721 ADPCM, and s = the range of sample rates supported. In the example below, s = 0 is 7200, s = 1 is 8000, and s = 2 is 11025 Hz.

+VSM=? produces the following:

n s = 0 1 2 0 ; G.721 ADPCM ; 4 ; (7200,8000,11025) 2 ; VSLEP ; 0.5 ; (9600) 3 ; id ; bpS ; (sample rates supported) 4 ; id ; bpS ; (sample rates supported) 8 ; id ; bpS ; (sample rates supported) where bpS is bits per sample

The standard would also include the formulae:

(Bits per Sample)*(Sample Rate)*1.25 = bits per second data stream (asynchronous between DCE and DTE).

(Bits per Sample)*(Sample Rate)/8 = characters per second in the data stream.

I/O CONTROL

The committee examined three possible ways of describing other possible voice I/O devices connected to the DCE. The first approach was a bit field declaration closely corresponding to hardware relays. The second approach: each possible configuration would be a logical device, and the DCE could select a logical device. The third approach followed the second approach, but was not as general in the selection of voice I/O lines, although it did enumerate the possibilities.

The following was presented to the committee by T. Nixon as a possible compromise. The committee discussed this at length, but did not find consensus.

First approach:

Bit Description I/O 0 Connect Telco to Phone ? 1 Connect DCE to Telco I/O 2 Connect DCE to Phone I/O 3 Connect DCE to Internal Mic I 4 Connect DCE to Internal Speaker O 5 Connect DCE to Gen'l Purpose Input I 6 Connect DCE to Gen'l Purpose Output O 7 Spare

The command would allow the values of 0-127, with a default of 1.

Bits correspond to relays in Table 2 (following page).

Table 3 (following page) presents +VL=? equivalents.

Second Approach

A second approach was considered as well. Although this work was presented, it was not discussed during the meeting as time ran short. This material may be discussed at the next meeting.

Input Code Output Code Telco In 0100h Telco Out 01h Phone in 0200h Phone Out 02h Int'l Mike 0400h Int'l Speaker 04h Mic Jack 0800h Speaker Jack 08h DTE Play 1000h DTE Record 010h Tone Gen 2000h Tone Receive 020h Mfr Spec 4000h Mfr Spec 040h Mfr Spec 8000h Mfr Spec 080h

The form of the command is:

+VL=

With considerable progress made, the ad hoc committee plans to further the work with a three day meeting April 21 - April 23, 1992 hosted by EXAR at the Crown Sterling Suites, Milpitas, CA.

Ken Krechmer, ACTION Consulting and Chris Sneed, Rockwell International

Telco Relay 0 connects Phone Telco and Phone Relay 1 connects DCE Relay 2 connects Telco to DCE Phone to DCE Int Mic Relay 3 connects Int DCE Relay 4 connects Int Int Speaker Mike to DCE Speaker to DCE GP Input Relay 5 connects GP DCE Relay 6 connects GP Ext Speaker input to DCE Out to DCE Table 2. Bits Corresponding to Relays

Device scheme Equivalent Sierra #s in Device scheme Equivalent Rockwell presented by Sierra the above scheme presented by #s in the above scheme Rockwell 0 1 0 2 1 3 1 4 2 2 2 16 or 64 3 4 3 8 or 32 4 97 4 6 5 96 6 99 7 98 Table 3. +VL=? Equivalents

ROSTER OF TR-29.2 DTE/DCE VOICE/FACSIMILE DIGITAL INTERFACE MARCH 25 - 26, 1992, C OSTA MESA, CA

Joe Decuir (Everex) Chairman, TR-29.2 Rockwell (Host)

ACTION Consulting Ken Krechmer AT&T Paradyne Joe Chapman Cirrus Logic George Grenley Exar Gordon Wall Hayes John Copeland Hayes Toby Nixon National Semicon. Moshe Doron Practical Peripherals Ian Seacombe Rockwell Chris Sneed Rockwell Ken Snyder Rockwell Stan Vecke Sierra Dave Long Sierra Mohammed Hunani STF Technologies Steve Myers The Complete PC Sam Weng Thought Comm. Philip Bogosian Yamaha Jay Virdy

LIAISONS

CTIA

R. Ameden (Bell Atlantic Mobile Systems [BAMS]) gave a brief report on the current status of the CTIA Microcell/Microsystems subcommittee. He reported (see TR-45.4/92.03.31.07) that the CTIA is waiting for feedback from TR-45.4 on the content of the guidelines. The CTIA is also preparing a User's Performance Requirements (UPR) for microsystems to be completed in the May/June timeframe of 1992. The UPR will be presented to the TR-45.4 subcommittee at the June 23, 1992 meeting in Vancouver, British Columbia, Canada.

T1P1

W. Lo of Northern Telecom gave the liaison report. There has not been a meeting of the T1P1 subcommittee since the last meeting of TR-45.4. However, contributions TR-45.4/92.03.31.05 and TR-45.4/92.03.31.06 were liaison statements remanded down from the TR-45 committee for review and response by TR-45.4. The TR-45 committee has remanded full liaison responsibility to TR-45.4 subcommittee to T1P1. The next meeting of T1P1 will be in Dallas on April 20-24, 1992.

The liaison back to T1P1 developed by TR-45.4 thanks them for the documents provided and notes: "These documents, in conjunction with others that have been received, are being used as input for the deliberation and development of a PCS Service Description ("PCSD") document."

TR-45.4 is in the process of reviewing the draft "Technical Report on System/Service Objectives for Low-Power Wireless Access for Personal Communications Services" (TR-45.4/92.02.20. 06), as well as the new section of the T1P1 working document addressing "Wireless Data Services". TR-45.4 intends to complete its review and draft formal comments at the next meeting of TR-45.4 (June 23, 1992)

FPLMTS PRESENTATION

M. Callendar, chairman of the International CCIR Task Group 8/1, gave a presentation (TR-45.4/92.03.31.16) concerning the Future Public Land Mobile Telephone Systems (FPLMTS). He provided the FPLMTS recommendations for service requirements and network architectures that have been approved (see below). Scheduled for approval in 1994 are recommendations on network interfaces, radio interfaces, QOS, network management and security. He also distributed the following documents:

TR-45.4/92.03.31.17 - WARC-92 Resolution Com4/4 Implementation of Future Public Land Mobile Telephone Systems (FPLMTS) TR-45.4/92.03.31.24 - IEEE International Conference on Selected Topics in Wireless Communications Advance Program (presented for information)

AD HOC COMMITTEE REPORTS

MICROCELL/MICROSYSTEM GUIDELINES (AHMMG)

The contributions below, concerning the CTIA Microcell/Microsystems Guidelines document, were remanded to the Ad Hoc CTIA Microcell/Microsystems Guidelines (AHMMG).

TR-45.4/92.03.31.12 - Async Data Service Description (from TR-45.3.2.5) (S. Jones - NEC) TR-45.4/92.03.31.13 - Data Services Working Paper (from TR-45.3.2.5) (S. Jones - NEC) TR-45.4/92.03.31.18 - Future Public Land Mobile Telephone Systems (FPLMTS) paper (M. Callendar, CCIR) TR-45.4/92.03.31.19 - CCIR Draft Rec.(DOC. 8/51) Services Supported on FPLMTS (M. Callendar, CCIR) TR-45.4/92.03.31.20 - CCIR Draft Rec.(DOC. 8/52) FPLMTS Network Architecture (M. Callendar, CCIR) TR-45.4/92.03.31.21 - CCIR Draft Rec. (DOC. 8/53) Satellite Operation Within FPLMTS (M. Callendar, CCIR)

TR-45.4/92.03.31.22 - CCIR Draft Rec. (DOC. 8/54) Adaption of FPLMTS to the Needs of Developing Countries (M. Callendar, CCIR) TR-45.4/92.03.31.23 - Proposed Revision to CCIR Rec. 687 (FPLMTS) (M. Callendar, CCIR)

The AHMMG report (TR-45.4/92.04.02.01) recommends that TR-45.4 address only the microcell standardization issues at this point, deferring microsystems standardization until a more complete definition is available from the CTIA in the form of a User's Performance Requirements (UPR is due September 1992).

AD HOC PCS SERVICE DESCRIPTIONS (AHPSD)

The above documents and TR-45.4/92.03.31.15, Cellular Mobile Telephone Service Descriptions (CMTSD) Revision 14 (S. Jones, NEC), were remanded to the Ad Hoc PCS Service Descriptions (AHPSD).

TR-45.4/92.04.02.02, Ad Hoc Committee for PCS Service Descriptions proposal to TR-45.4 to use the CMTSD for a PCS service description baseline document, states:.

TR 45.4 intends to use the Cellular Mobile Telephone Service Description ("CMTSD" Revision 14 PN-2717, TR-45.4/92.03.31.15) as baseline text for its PCS Service Description document. TR-45.4 believes there should ultimately be a single document for PCS Service Descriptions, which would include the ongoing evolution of the CMTSD. TR-45.4 is willing to administer and maintain such a document. However, in view of the fact that other TR-45 subcommittees have an interest in this document, TR-45.4 would be amenable to having the administration and maintenance of the document reside elsewhere within the domain of the TR-45 Committee.

Reporter's Note: The CMTSD document was discussed at the TR-45 Committee meeting on April 10, 1992 in San Antonio, TX. TR-45 determined that it was premature for the combining of the CMTSD for use by all subcommittees of TR-45. The TR-45.4 subcommittee should proceed with their own PCS Service Descriptions with consideration of commonalty with the CMTSD.

AD HOC AREAS OF STANDARDIZATION (AHAS) The T1P1 working documents and related contributions (TR-45.4/92.03.31.05, TR-45.4/92.03.31.06, TR- 45.4/92.03.31.12, TR-45.4/92.03.31.13, and TR-45.4/92.03.31.18 through TR-45.4/92.03.31.23) were submitted to AHAS. TR-45.4/92.04.02.04, the ad hoc committee report, consists of 3 sections:

• Description of standardization areas for PCS • Standards Development Plan • Recommended Structure for TR-45.4 in 1992

WORK PLAN Based on the input of the TR-45.4 ad hocs, the TR-45.4 committee agreed to the following:

WORK PLAN FOR 1992:

Activities: PCS standards structure and methodology Liaison coordination with T1P1, Telocator, and CTIA Liaison coordination, via TR-45, with national committees CCIR and CCITT Microcell standards Standards areas: Guide to TIA PCS standards PCS concepts, definitions, and service characteristics standard PCS Service descriptions standard PCS reference models standard

WORK PLAN FOR 1993:

Activities: Revise Standards from 1992 Liaison coordination as above Recommended division of work within TR-45 Standards areas: Wireless Access Interfaces (Speech processing as required) Network Interfaces(Inter-system) Dialing Procedures (Numbering) Automatic Roaming Operations, Administration and Maintenance Charging and Message Accounting Conformance Testing WORK PLAN FOR 1994: Activities: Revise Standards from 1993 Liaison coordination as above Recommended division of work within TR-45 Standards areas: Data Services Authentication and Privacy Etc.

TR-45.4 STRUCTURE The subcommittee has determined a structure to accomplish the 1992 work plan with the formation of three working groups. There is a request to the membership companies to formally nominate the chairs for these working groups by a letter on their letterhead expressing their support both financially and with dedicated time for their nominee as chairman of the working group.

The working groups formed were:

• Working Group I, PCS Services Standards

• Working Group II, PCS Standards Development Planning - Overall PCS Standards Development Plan - Liaison coordination: T1P1, Telocator, CTIA, as well as other relevant organizations - Liaison with national CCITT and CCIR will be through the TR-45 committee.

• Working Group III, Microcell Standards

TR-45.4 PLENARY ROSTER, MARCH 31 - APRIL 2, 1992, IRVING, TX Stephen S. Jones (NEC America, Inc.) Chairman, TR-45.4 Ameritech Mobile George Geotsalitis Asahi Chemical Koji Goto Astronet Corp. Tak Imamura AT&T Bell Labs Charles Cooke AT&T Bell Labs John A. Marinho Bell Atlantic Mobile Richard Ameden Bell Cellular Vino Vinodrai Bell South Ent. Douglas O'Neil Bellcore P.J. Louis Cantel Peter Oldfield CBIS Edward Sparks Dept. of Defense Mike Uerkvitz DSC Communications David Self EDS Pers. Comm. Corp Nick Zoda Ericsson Tariq Rahman Fujitsu N/W Trans.Sys Rajeev Krishnamurthi GTE Gov't Systems Dave Weissman GTE Labs James Yu GTE Mobile Comm. Dale Baldwin GTE Telecomm. Svc. Jeff Crollick HNS Enrique Laborde IMM Gil LaVean IMM D. R. Bolgiano Japan Radio Company Mat Kirimura McCaw Cellular David Holmes MCI Robert Voss Midgley & Assoc. Harry Midgley Millicom/PCN America Gary K. Jones Motorola Tony Akers Motorola, Inc Ralph Kamin Motorola, Inc. Graham Haddock MPR Teltech Mike Callendar NEC America, Inc. Ed Ornelas Nokia Laura Siren Nokia Kimmo Mylhymaki NovAtel Mike Mah-Poy NovAtel Arif Kurji NTI Wing Lo NTI Gary Boray NTI Kelly Hollis OKI America Reed Fisher OKI Electric Co., Ltd. Takao Suzuki Omnipoint Logan Scott PacTel Corp. Huel Halliburton Panasonic John Avery Qualcomm Mark Epstein Rockwell Int'l Thomas P. Jones Rogers Cantel Peter Oldfield Sharp Prem Sood Sony Gerald Wahl Southwestern Bell Terry Watts Texas Instruments Panos Papamichalis Texas Instruments John Barnett TIA Eric Schimmel U S West New Vector Doug Reudink

36 Vol. 3.3 Copyright © CSR 1992 April, 1992 COMMUNICATIONS STANDARDS REVIEW VOICE RELATED EXTENSIONS TO THE AT COMMAND SET: A MEETING OF VENDORS, APRIL 7, 1992, SAN JOSE, CA A group of software, hardware and semiconductor vendors has coalesced to create extensions to the AT command set to support voice related capabilities. While this group is not a formal standards making body, the wide interest in voice-related functions prompts CSR to include this report. The participants agreed to have the report of this meeting published in CSR. D. Long (Sierra) distributed a two page comparison of the different voice commands drafts in existence and a marked-up copy of TR-29.2/92-25, Voice Communications Protocol Extensions for AT Command Set, which included the changes agreed to at the March 25 and 26, 1992, TR-29.2 meeting on voice commands. The committee proceeded to review the comparison paper to refine agreements where possible. The IVP committee is interested in maintaining compatibility with the TR-29 committee work wherever possible. Depending on the timing of the completion of the work in TR-29.2 on voice commands, it is possible that members of the IVP will bring out independent voice command interfaces. K. Krechmer (ACTION Consulting) recommended that such proprietary interfaces utilize the #V command interface to avoid future compatibility problems. K. Krechmer noted that the next TR-29 meeting (May 5 - 7) occurs prior to the end of the ballot period for PN- 2388B (Class 2). Some issues (class switching, reset, etc.) that relate to voice commands are included in the PN- 2388B work. This indicates that the next meeting of TR-29 likely cannot complete work on the voice commands. Therefore, the earliest date for completion of the voice command work would be the TR-29 meeting of August 3-6, 1992. The committee considered the issue of event mask. Rockwell is interested in a separate transmit and receive event mask. The IVP proposal utilizes a single event mask. There is no reluctance in the IVP group to support multiple event masks, assuming there is a technical reason. It was agreed to not use the S10 register for voice related timing and to use a separate register instead. Lc,n command noted in the Sierra document is used for silence insertion and deletion. This command needs to change as L is already used. Reviewing the +VSM command, the committee will support having the s parameter describe the rate desired not as an index. The Sierra proposal proposes a host wake-up capability. This requires a separate physical function to perform the actual wake-up that is left undefined. The committee is interested in this capability. It was agreed that record and playback suggest true recording. It would be more accurate to state transmit and receive (VTR and VRC). The Sierra paper suggests the command as a way to clear transmit buffer in transparent mode. Cirrus Logic noted the need to increase the buffer size of the skid command to allow sufficient time when high bit rate voice coding is used. It was agreed to change the parameter to n*16 octets. The remaining more contentious issues will be discussed at the coming TR-29.2 ad hoc meeting. Ken Krechmer, ACTION Consulting

ROSTER OF THE VOICE RELATED EXTENSIONS TO THE AT COMMAND SET, APRIL 7, 1992, SAN JOSE, CA Sam Weng, The Complete PC (Host/Chairman) ACTION Consulting Ken Krechmer Cirrus Logic George Grenley Phylon Hamdi El-Sissi Rockwell Mark Chapman Sierra Dennis Chan Sierra Dave Long The Complete PC Mike Henschell The Complete PC C.C. Su

ACRONYM GLOSSARY AGC Automatic Gain Control AHMMG Ad Hoc Microcell/Microsystems Guidelines BRA Basic Rate Access BT British Telecom (United Kingdom PTT) CBEMA Computing Business Equipment Manufacturers Association CCIR Consultative Committee International Radio CCITT Consultative Committee International Telephone and Telegraph CD Committee Draft CEC Canadian Electric Code CFA Carrier Failure Alarms (s) CI Customer Interface CMTSD Cellular Mobile Telephone Service Descriptions CO Central Office CPE Customer Premise Equipment CSA Canadian Standards Association CS Canadian Standard CSR Communications Standards Review CTIA Cellular Telecom. Industry Association DID Direct Inward Dialing DIS Draft International Standard DOC Department of Communications (Canada) DSI Digital Speech Interpolation DTE Data Terminal Equipment EIA Electronic Industry Association EMC Electromagnetic Compatibility ESD Electrostatic Discharge ETSI European Telecom. Standards Institute FCC Federal Communications Commission FPLMTS Future Public Land Mobile Telephone Systems GSM Groupe Speciale Mobile HSSI High Speed Serial Interface IEC International Electrotechnical Comm. ISPBX Integrated Services Private Branch Exchange ISDN Integrated Services Digital Network ISO International Standards Organization ITAR International Traffic in Arms Regulations IVP Integrated Voice Protocol JEM Joint Experts Meeting JTC Joint Technical Committee LADC Local Area Data Channels LOS. Loss of Signal NEC National Electric Code (US) OOF Out of Frame OSI Open Switching Interval PBX Private Branch Exchange PCM Pulse Code Modulation PCS Personal Communication Systems PRA Primary Rate Access PSTN Public Switched Telephone Network PTT Public Telephone and Telegraph RAL Restricted Access Location RLP Radio Link Protocols SSD Shared Secret Data SWG Sub Working Group TAPAC Terminal Attachment Program Advisory Committee TE ISDN Terminal TIA Telecommunications Industry Association

TSB Telecommunication Systems Bulletin (TIA) TSSC Technical Standards Subcommittee UL Underwriters Laboratories UPR Users Performance Requirements VAD Voice Activity Detector VAF Voice Activity Factor

1992 MEETING SCHEDULES AS OF APRIL 20 Subject to Change without Notice

TR-45.5 Apr 21 - 23 Niagara Falls, Ont. TR-29 Aug 3- 6 Portland, OR TR-45 JEM Apr 22 - 24 Niagara Falls, Ont. TR-45.4 Aug 4-6 San Francisco, CA SG VIII Apr 22 - 30 Geneva T1E1 Aug 17-21 Portland, OR TR45.1.4 Apr 27 - 28 Banff, Alb TR-45.2 Aug 17-21 Seattle, WA TR-45.3 Apr 27-May 1 Banff, Alb TR-41 Sep 14-18 Victoria, BC TR-29 May 4 - 7 Berkshires, MA TR-45.4 Sep 15-17 St. Louis, MO T1S1 May 11 - 15 Chicago, IL TR-45.2 Sep 21 - 25 Walnut Creek, CA TR-30 May 11 - 15 Huntsville, AL V.fast Rap Sep 28 - 30 London, UK TR-45.1 May 14 Denver, CO TR-45.3 Oct 5 - 9 Richardson, TX TR-41.8.4 May 14 - 15 New Jersey TR-30 Oct 12-16 MA or Toronto, Ont TR-45.2 May 18-22 Atlanta, GA TR-45.4 Oct 20-22 Orlando, FL T1E1 May 18 - 22 Williamsburg, VA T1S1 Nov 2 - 6 --- TR-45.3 Jun 1 - 5 Ontario or Quebec TR-45.2 Nov 2 - 6 Atlanta, GA V.fast rap Jun 4 - 5 Munich TR-29 Nov 9 - 12 San Antonio, TX SG XVII Jun 8 - 12 Geneva TR-45.3 Nov 16 - 20 --- TR-41.7.2 Jun 13 - 14 St. Johns, NFLD T1E1 Nov 30-Dec 4 Anaheim, CA TR-41 Jun 15 - 19 St. Johns, NFLD TR-45.2 Nov 30-Dec 4 Orlando, FL TR-45.2 Jun 15 - 19 Calgary, Alb TR-30 Dec 14 - 18 Orlando, FL TR-45.4 Jun 23 - 25 Vancouver, BC TR-41 Dec 7 - 11 Santa Rosa, CA TR-45(all) Jul 6 - 17 Denver, CO TR-45.4 Dec 9 - 11 Phoenix, AZ TR-30 Jul 27 - 31 Newport Beach, CA TR-45.3 Dec 14 - 18 --- TR-45.2 Jul 13-17 Calgary, Alb T1E1 Jul 19 --- T1S1 Aug 3-7 Eatontown, NJ

1993 MEETING SCHEDULES AS OF APRIL 20 Subject to Change without Notice

WP XVII Jan 12 - 15 Geneva TR-41 Sept 13 - 17 Harrisburg, PA TR-41 Mar 15 - 19 Corpus Christi, TX TR-41 Dec 13 - 17 Monterey, CA TR-41 June 21 - 25 Toronto, Ont

The next issue of Communications Standards Review will be published May, 1992.

Communications Standards Review is published about 8 times per year, within days after the latest, related standards meetings. Editor: Elaine J. Baskin, Ph.D. Technical Editor: Ken Krechmer. Copyright © 1992, Communications Standards Review. All rights reserved. Copying of individual articles for distribution within an organization is permitted. Subscriptions: $695.00 per year North America, $895.00 per year outside North America. Corporate 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. 13903