DOCSLIB.ORG

ID ARES Digital Comms.Key

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
ID ARES Digital Comms.Key Idaho ARES Digital Communications Principles 1 • This set of slides serves to provide a foundation for Emergency Coordinators, NET Managers and NET control operators in determining what practices and procedures are to be adopted. • Although some slides are applicable towards addressing HOW to conduct digital communications, the focus here is on WHY certain principles should be considered when designing digital communications practices. • A comprehensive document, focusing on the HOW of digital communications, is being prepared for publication on the Idaho ARES web site on how to conduct digital communications. 1 60-Meters Needs to be Considered • The Most Restrictive of Bands - NTIA vs FCC - NTIA Assigned Frequency vs VFO - Digital Communications centered on NTIA assigned frequency ‣ Digital Communications centered on 1500 Hz • Interoperability • 60m Practices can be applied to any band • Practices on other bands may not be applicable on 60m 2 • The 60-meter amateur radio band presents the most restrictive regulatory requirements for digital operations. 60-meters also presents the only operational opportunity to directly communicate with another radio service, and specifically, FEMA. - Amateur Radio is a secondary allocation on 60-meters. The primary allocation is for Federal stations that operate under the authority of the National Telecommunications and Information Administration (NTIA), not the FCC. FCC regulations for Amateur Radio operations on the 60-meter band inherit the requirements of NTIA regulations. - NTIA allocates channels based on the assigned center frequency. The VFO frequency is offset by one half of the channel bandwidth from the assigned center frequency. For example, the NTIA allocation for 60m channel 1 has an assigned frequency of 5332 kHz, and with a channel bandwidth of 3 kHz, the VFO frequency is 5330.5 kHz Upper Side Band. - Digital communications must be centered on the NTIA assigned frequency. For 60m channel 1, with a VFO frequency of 5330.5 kHz, the digital transmissions must be centered on 1500 Hz on the waterfall display. - If all digital communications, regardless of band, are centered on 1500 Hz, operations and training can be unified across all bands. If a different insertion point is chosen, 60m will still require that 1500 Hz be used and you will then have different operating practices based on band. 2 - The FCC provides a waiver to allow direct communications on the 60-meter band between Amateur Radio stations and stations authorized under the NTIA primary allocation (ie. FEMA, DHS SHARES, MARS, USCG Auxiliary, etc.). Practices need to support the opportunities for interoperability inherent in 60m operations. 2 NET Goals • Time efficient and accurate communication with the ability to convey a high volume of traffic 3 • Within the Incident Command System, all activities are incidents. This includes: - Training - Exercises - Public Service communications - Civil or Natural Disaster • In an incident, we never know ahead of time what volume of traffic we may be required to handle. Because of this unknown variable, it is best that we treat all incidents, real or practiced, as if a very high volume of traffic will need to be handled. 3 Traffic Handling Goals • 100% Data Fidelity • Guaranteed Delivery of Data • Consume as little time as possible (Network Bandwidth Consumption) 4 4 What Inhibits Achieving The Desired Goals? • Repeated Transmissions • Requests for FILLS • Unnecessary Verbose Language • Conveying Unnecessary Information • Controlled Interference - Simultaneous Transmission 5 • Repeated transmissions may be required when the data fidelity in the received message is so poor that requesting fills would impose a greater loss of network data handling capacity than retransmitting the message. This can occur due to poor copy resulting from poor propagation, interference or incorrect modem selection. • Requesting FILLS occurs when there is a minor loss of data fidelity in order to correct errors in the copy. Requesting FILLS degrades the data capacity of the network. • Unnecessary verbose language degrades the data handling capacity of the network. • Conveying unnecessary information degrades the data handling capacity of the network. • Controlled interference can result in requests for FILLS or retransmission. Controlled interference occurs when simultaneous transmission occurs. Simultaneous transmission is common during NET check in, but should be rare at other times during NET operation. After NET check in, simultaneous transmission usually occurs due to an operator not maintaining NET situational awareness or because of poor circuit discipline. 5 What Inhibits Achieving The Desired Goals? • Things we don’t have control over - Propagation - Noise Floor - Uncontrolled Interference ‣ Emissions from Electronic Devices, Foreign Broadcast, RADAR, CODAR, Non-participating Transmissions, etc. 6 • In some cases, propagation can be mitigated by proper band selection, but this is not always the case. The MUF or foF2 NFIS critical frequency may be so low that propagation is poor on any band. • The noise floor may be high, and especially when a solar event has occurred. The D-Layer may become ionized, resulting in signal attenuation at lower frequencies. Under severe conditions, the D-Layer absorption frequency may be higher than the MUF or foF2 NVIS critical frequency, making HF unusable. • Emissions from other non-participating stations or from electronic devices may cause interference. 6 What Supports Achieving The Desired Goals? • Brevity - Supported by use of PROSIGNs, Q-CODES & Z-CODES • Proper Transmit Audio Level (with no ALC activity) • Proper Receive Audio Level • Circuit Discipline - NET Situational Awareness - Structured Use of RELAY Stations - Delimit Noise from Transmitted Content 7 • Brevity is a major contributor to increasing the traffic handling capacity of a NET. • Prosigns, Q-Codes and Z-Codes can be used to help manage communications operations. • Under no circumstances should Prosigns, Prowords, Q-Codes or Z-Codes be included in the body of a message. The body of the message should adhere to the ICS standard of using Plain Text only. • Proper receiver adjustment will maximize performance in copying digital traffic, and reduce the need for retransmission of requests for fills. • Circuit discipline, supported by NET situational awareness and structured communications, serves to avoid simultaneous transmission, which reduces the need for retransmission or fill requests. • Random characters in the receive buffer, largely resulting from pure noise or a low SNR, can be somewhat mitigated by adding vertical space at the start and end of a digital transmission. 7 What Supports Achieving The Desired Goals? • Brevity - Supported by use of PROSIGNs & Q-CODES PROSIGN MEANING DEFINITION AA ALL AFTER The portion of the message to which I refer is all that follows (word/ number). AB ALL BEFORE The portion of the message to which I refer is all that precedes (word/ number). AR OUT Use to end a transmission when no reply is required or expected. AS WAIT I must pause for a few seconds. AS AR WAIT OUT I must pause for more than a few seconds. BN ALL BETWEEN The portion of the message to which I refer is all that follows (word/ number) and precedes (word/ number). BT BREAK Indicates the separation of text from other portions of the message. C CORRECT You are correct. What you have transmitted is correct. CFM ACKNOWLEDGE Instructs the addressee to acknowledge the message. CL CLOSE Announcing station shutdown. DE FROM Delimits the call sign of the called station from the call sign of the calling station. HH AR DISREGARD OUT This transmission is in error, disregard it. No response is needed. INT INTEROGATIVE Used to indicate that the question version of the prosign that follows is to be used. K OVER Use to end a transmission when a response is required. N NEGATIVE NO. R ROGER I have satisfactorily received your last transmission. WA WORD AFTER The message word to which I refer follows (…). WB WORD BEFORE The message word to which I refer precedes (…). 8 • This table of prosigns is useful in managing communications operations. • Prosigns should not appear within the body of a message. 8 What Supports Achieving The Desired Goals? • Brevity - Supported by use of PROSIGNs & Q-CODES Q-CODE INTEROGATIVE ANSWER/STATEMENT QNI MAY I JOIN THE NET YOU MAY CHECK IN QRK WHAT IS THE READABILITY OF MY SIGNALS THE READABILITY OF YOUR SIGNALS IS … QRM DO YOU HAVE INTERFERENCE? I HAVE INTERFERENCE QRN ARE YOU TROUBLED BY STATIC? I AM TROUBLED BY STATIC QRQ SHALL I SEND FASTER (MODEM CHANGE)? SEND FASTER (MODEM CHANGE) QRS SHALL I SEND SLOW (MODEM CHANGE)? SEND SLOWER (MODEM CHANGE) QRU HAVE YOU ANYTHING FOR ME? I HAVE NOTHING FOR YOU QRV ARE YOU READY? I AM READY QRZ WHO IS CALLING ME? YOU ARE BEING CALLED BY… QSL CAN YOU ACKNOWLEDGE RECEIPT? I ACKNOWLEDGE RECEIPT QSM SHALL I RESEND MESSAGE (MESSAGE NUMBER)? RESEND MESSAGE (MESSAGE NUMBER) QSP WILL YOU RELAY MESSAGE TO … ? I WILL RELAY MSG TO … QTC HOW MANY MESSAGES HAVE YOU TO SEND? I HAVE … MESSAGES TO SEND (APPEND PRECEDENCE HERE) QUC WHAT IS THE NUMBER OF THE LAST MSG RCVD? THE NUMBER OF THE LAST MSG RCVD IS … 9 • This list Q-Codes is not comprehensive. • When sending the interrogative version of the Q-CODE, always prefix the interrogative Q-Code with the INT prosign. • NOTE: Other services (i.e. Army MARS, Air Force MARS, USCG Auxiliary, SHARES, etc.) use Z-Codes for the same purpose that Q-Codes are used. 9 Data Fidelity and Brevity • Effects of Forward Error Correction on Transmission Length 10 • Forward Error Correction, or FEC, improves data fidelity. • There is a tradeoff between data fidelity and brevity when using FEC. • Data fidelity is more important than brevity. • We’ll explore this further. 10 Data Fidelity and Brevity • Effects of Forward Error Correction on Transmission Length - More data bits are transmitted than required to represent the message content 11 • With Forward Error Correction, the length of transmission is increased due to the inclusion of Forward Error Correction codes.
Load more

Recommended publications
  • Efficient Multi-Carrier Communication on the Digital Subscriber Loop
    Efficient Multi-Carrier Communication on the Digital Subscriber Loop Donnacha Daly Department of Electrical and Electronic Engineering Faculty of Engineering and Architecture University College Dublin National University of Ireland A thesis presented to the National University of Ireland Faculty of Engineering and Architecture in fulfillment of the requirements for the degree of Doctor of Philosophy May 2003 Research Supervisors: Dr. C. Heneghan Prof. A. D. Fagan Head of Department: Prof. T. Brazil Abstract This thesis explores three distinct philosophies for improving the efficiency of multi-carrier com- munication on the digital subscriber loop. The first topic discussed is impulse response shortening for discrete multitone transceivers. The minimum mean-squared error impulse response shortener is reformulated to allow near-optimal rate performance. It is demonstrated that the best existing eigen-filter designed channel shortener is a particular case of the proposed reformulation. An adap- tive time-domain LMS algorithm is provided as an alternative to eigen-decomposition. The next part of the thesis examines bit- and power- loading algorithms for multitone systems. The problem of rate-optimal loading has already been solved. It is shown, however, that the rate-optimal solu- tion does not give best value for complexity, and that near optimal schemes can perform very well at a fraction of the computational cost. The final section of the thesis is a brief exposition of the use of wavelet packets to achieve multi-carrier communication. It is proposed that the non-uniform spectral decomposition afforded by wavelet packet modulation allows reduced inter-symbol inter- ference effects in a dispersive channel.
    [Show full text]
  • FLDIGI Users Manual 3.23
    FLDIGI Users Manual 3.23 Generated by Doxygen 1.8.10 Sat Sep 26 2015 10:39:34 Contents 1 FLDIGI Users Manual - Version 3.231 1.1 Fldigi Configuration and Operational Instructions........................... 1 2 Configuration 3 2.1 User Interface configuration...................................... 3 2.2 Windows Specific Install / Config................................... 3 2.3 Other Configuration options...................................... 3 2.4 Command Line Switches ....................................... 4 2.5 Modem Configuration Options..................................... 4 2.6 Configure Operator .......................................... 5 2.7 Sound Card Configuration....................................... 6 2.7.1 Right Channel Audio Output ................................. 9 2.7.2 WAV File Sample Rate.................................... 10 2.7.3 Multiple sound cards ..................................... 10 2.8 Rig Control .............................................. 12 2.8.1 Rig Configuration....................................... 13 2.8.2 RigCAT control........................................ 15 2.8.3 Hamlib CAT control...................................... 16 2.8.4 Xml-Rpc CAT......................................... 16 2.9 New Installation............................................ 17 2.10 Configure ARQ/KISS I/O ....................................... 20 2.10.1 I/O Configuration....................................... 22 2.10.1.1 ARQ I/O ...................................... 22 2.10.1.2 KISS I/O...................................... 23
    [Show full text]
  • Replacing 1200 Baud AFSK FM with PSK and Deploying DTN Iain Young [email protected]
    Replacing 1200 Baud AFSK FM with PSK and Deploying DTN Iain Young [email protected] Agenda ● Introductions ● AX.25 Link Established! ● Exactly What Are We ● Adding TCP/UDP/IP Planning To Replace ? ● Adding DTN ● Why Replace It ? ● Results ● Computer Network Theory ● Conclusions ● How We Replaced It ● Future Experiments – Tools and Utilities Needed ● Acknowledgements – RF Setup and Maps Introductions ● Two major areas of focus – Replacing AX.25 1200 baud AFSK FM with PSK – Deploying DTN ● Who ? – Iain Young, G7III, MAXPAK Chairman – Dave Madew, M0DCM, MAXPAK Committee Member ● MAXPAK – Formed as a dedicated AX.25 Packet group for the Midlands – Constitution changed a couple of years ago, to include all digital modes So What Are We Replacing, And What Are We Not Replacing ? ● The AX.25 Physical Layer – In “Network” Parlance, Layer 1 – We mean the 1200 baud AFSK FM transmissions ● We are not replacing what the network world would call “Layer 2” or “The Data Link Layer” where you send and receive AX.25 frames to and from AX.25 addresses ● The mode we are all familiar with could be more formally described as AX.25 over 1200 baud AFSK FM ● The mode we will be creating could be more formally described as AX.25 over PSK Why Do This ? (1) ● 1200 baud AFSK FM is not exactly well known for it's effeciency, especially with regards to: – Spectrum usage, – Power requirements – Link budget ● Even it's 300 baud cousin is not particularly well thought of on HF, can be improved on and that's only a quarter the throughput! Why Do This ? (2) ● Plenty have claimed
    [Show full text]
  • HF Digital Mode Primer
    HF Digital Mode Primer By Val Campbell K7HCP INTRODUCTION Getting started using the Amateur Radio Digital Modes of communications can be confusing and frustrating at times but it doesn’t have to be that way. The purpose of this primer is to introduce you to the basics of using this fun to use mode of communication and to provide you with the understanding of the processes to setting up your hardware and software to easily and quickly start copying and later to start sending digital communications on the amateur radio HF shortwave bands. The minimum hardware requirements to receive or copy HF digital communications are a personal computer (PC) with a standard sound card and a short wave or ham radio receiver with SSB mode. A receiver with digital tuning display is preferred but a receiver with analog tuning can work also. You may have heard about various digital modes such as RTTY, SSTV, PACTOR, PSK31, and of course, CW. CW or Morse Code, as it is more commonly known, was the original digital mode used in communications; however few thought of it as digital until recently. Just like our old wristwatches were analog watches, we didn’t think of them as such until digital watches came into existence. PSK31 has become by far the most popular digital mode used by amateur radio operators lately. PSK31 stands for Phase Shift Keying with a bandwidth of only 31 hertz. That’s really all you need to know to use this mode of communications. The program does the rest for you. The ARRL has the following to say about PSK31 : Since the spring of 1999, PSK31 has taken off like wildfire.
    [Show full text]
  • Overview of Ham Radio Software
    OVERVIEW OF SOFTWARE FOR DIGITAL HAM RADIO Where to download free software: (often there are helpful help files also, so you might want to peruse around a bit more than just download) FLDIGI https://sourceforge.net/projects/fldigi/files/fldigi/fldigi- 3.23.15_setup.exe/download https://sourceforge.net/projects/fldigi/files/fldigi/ Downloading FLDIGI can be a bit tricky. Try going to the above page and then selecting (for Windows) the file ending with “setup.exe”. WINLINK EXPRESS http://www.winlink.org/sites/default/files/downloads/winlink_express_insta ll_1-4-2-0.zip UZ7HO http://uz7.ho.ua/modem_beta/soundmodem95.zip is the actual download. SOUNDMODEM.EXE WINDOWS BPQ http://www.cantab.net/users/john.wiseman/Downloads/LastestInstaller/ is the directory http://www.cantab.net/users/john.wiseman/Downloads/LastestInstaller/BPQ 32_6.0.13.1_20160927.exe is the actual download link Malware Detection Software: Many commercial virus checkers and malware detectors will consider very rare software to be automatically suspect, and delete or refuse to run or load it. You will have to find out how to tell your malware detection software to accept these quite- respectable programs. Every malware detection program works differently, so read your instructions! Digital Ham Radio has many facets. Characters from a computer become some version of “tones” going to a transmitter microphone input; audio from a receiver speaker output gets transformed into characters in a computer and possibly visible on the screen to a user. Software & hardware combine to make this magic happen. This paper will attempt to categorize the major software required to accomplish several communications.
    [Show full text]
  • 16.1 Digital “Modes”
    Contents 16.1 Digital “Modes” 16.5 Networking Modes 16.1.1 Symbols, Baud, Bits and Bandwidth 16.5.1 OSI Networking Model 16.1.2 Error Detection and Correction 16.5.2 Connected and Connectionless 16.1.3 Data Representations Protocols 16.1.4 Compression Techniques 16.5.3 The Terminal Node Controller (TNC) 16.1.5 Compression vs. Encryption 16.5.4 PACTOR-I 16.2 Unstructured Digital Modes 16.5.5 PACTOR-II 16.2.1 Radioteletype (RTTY) 16.5.6 PACTOR-III 16.2.2 PSK31 16.5.7 G-TOR 16.2.3 MFSK16 16.5.8 CLOVER-II 16.2.4 DominoEX 16.5.9 CLOVER-2000 16.2.5 THROB 16.5.10 WINMOR 16.2.6 MT63 16.5.11 Packet Radio 16.2.7 Olivia 16.5.12 APRS 16.3 Fuzzy Modes 16.5.13 Winlink 2000 16.3.1 Facsimile (fax) 16.5.14 D-STAR 16.3.2 Slow-Scan TV (SSTV) 16.5.15 P25 16.3.3 Hellschreiber, Feld-Hell or Hell 16.6 Digital Mode Table 16.4 Structured Digital Modes 16.7 Glossary 16.4.1 FSK441 16.8 References and Bibliography 16.4.2 JT6M 16.4.3 JT65 16.4.4 WSPR 16.4.5 HF Digital Voice 16.4.6 ALE Chapter 16 — CD-ROM Content Supplemental Files • Table of digital mode characteristics (section 16.6) • ASCII and ITA2 code tables • Varicode tables for PSK31, MFSK16 and DominoEX • Tips for using FreeDV HF digital voice software by Mel Whitten, KØPFX Chapter 16 Digital Modes There is a broad array of digital modes to service various needs with more coming.
    [Show full text]
  • HF Digital Communications
    HF Digital Communications How to work those strange sounds you hear on the air John Clements KC9ON Stephen H. Smith WA8LMF Joe Miller KJ8O John Mathieson AC8JW Brian Johnston W8TFI 1 May 2014 Contents Introductions Why Digital? Digital Modes of Operation Hardware : Radio, Computer, and interfaces Contents Software Tips and Tricks Q&A Introductions John Clements KC9ON Licensed in 1979 at age 16 Retired from electronics manufacturing and IT systems Active experimenter and home brewer [email protected] Introductions Stephen Smith WA8LMF Land-Mobile-Radio Systems & Field Engineer Ham since 1964 [email protected] Introductions Joe Miller KJ8O SWL since 1967, first licensed in 2006 and collects QSL cards President of OCARS (W8TNO) Certified Public Accountant [email protected] Introductions Brian Johnston W8TFI Licensed in 1976 Computer operator for a major newspaper Avid experimenter and home brewer [email protected] Introductions John Mathieson AC8JW Licensed since about 2005 Active in CW and digital modes [email protected] Why Digital? Send and receive text, images, data, and audio Some modes work very well in noisy and weak signal environments If you can’t hear them you can’t work them is no longer true! Why Digital? Some modes can provide error free or reduced error transmissions. Good for Emergency Communications Why Digital? Many modes use smaller bandwidths than voice 97.1(b) contribute to the advancement of the radio art. 97.313(a) use the minimum transmitter power necessary to carry out the desired
    [Show full text]
  • DM-780 Users Guide Ham Radio Deluxe V6.0
    HRD Software LLC DM-780 Users Guide Ham Radio Deluxe V6.0 By Tim Browning (KB3NPH) 2013 HRD Software LLC DM-780 Users Guide Table of Contents Overview ....................................................................................................................................................... 3 Audio Interfacing........................................................................................................................................... 4 Program Option Descriptions ....................................................................................................................... 8 Getting Started ............................................................................................................................................ 10 QSO Tag and My Station Set up .............................................................................................................. 11 My Station Set Up ................................................................................................................................... 12 Default Display ............................................................................................................................................ 14 Main Display with Waterfall ................................................................................................................... 14 Main Display with ALE and Modes Panes ............................................................................................... 15 Modes, Tags and Macros Panes .............................................................................................................
    [Show full text]
  • Digital Mode Presentation
    Digital Mode Presentation General Knowledge Digital communication is the exchange of digital data over the air • Email, Digital files, Keyboard-to-keyboard (chat), and others Protocols on today’s menu • RTTY, PACTOR, JT9/65, PSK31, FSQCall, Olivia Communication = digital mode if info is exchanged as individual characters encoded as digital bits. Example: A = ASCII 01000001 Some consider CW a digital mode. (an A = di-dah) Some modes are old, like radio-teletype, invented in the 1930’s. Some modes are new, like FSQ, invented in the mid-2015’s. Where? • Look at an amateur band chart (80 meters and 20 meters) • Look at a band plan (2-4, 2-17, 6-2) • Show CW, PSK31 (3.570 & 14.070) and RTTY • Look at http://bandplans.com Definitions Air Link – the part of the communication system involving radio transmissions and reception of signals. Bit – fundamental unit of data; a 0 or 1 in binary Bit rate – number of bits per second sent from one system to another. Symbol – signal characteristics that make up each distinct state of the transmitted signal • CW symbols = on and off • RTTY symbols are tones • Baudot or ASCII (simple methods) encode one bit in each symbol • Sophisticated codes use complex audio signals to carry the data and encode more than one bit in each symbol Baud – number of symbols per second that are sent from one system to another. Duty cycle – ratio of transmitting to total on/off time • Important to know duty cycle of mode because most transmitters are not designed to operate at full power for extended periods of time.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 6,665,546 B2 Slaughter Et Al
    USOO6665546B2 (12) United States Patent (10) Patent No.: US 6,665,546 B2 Slaughter et al. (45) Date of Patent: *Dec. 16, 2003 (54) HIGH SPEED, POINT-TO-POINT, (56) References Cited MILLIMETER WAVE DATED COMMUNICATION SYSTEM U.S. PATENT DOCUMENTS 5,701,591 A * 12/1997 Wong .......................... 455/63 (75) Inventors: Louis Slaughter, Weston, MA (US); 5,890.055 A * 3/1999 Chu et al...................... 455/23 Jon Hill, Socorro, NM (US); Thomas 5.936,578 A * 8/1999 Driessen et al. .............. 455/65 Lambert, Makawao, HI (US); Huan Nguyen, Annandale, VA (US); Randall (List continued on next page.) Olsen, Carlsbad, CA (US); John Lovberg, San Diego, CA (US); Primary Examiner William Trost Kenneth Y. Tang, Alpine, CA (US); ASSistant Examiner Rafael Perez-Gutierrez Vladimir Kolinko, San Diego, CA (74) Attorney, Agent, or Firm John R. Ross; John R. Ross, (US) III (73) Assignee: Trex Enterprises Corporation, San (57) ABSTRACT Diego, CA (US) A point-to-point, wireless, millimeter wave trunk line com (*) Notice: Subject to any disclaimer, the term of this munications link at high data rates in excess of 1 Gbps and patent is extended or adjusted under 35 at ranges of Several miles during normal weather conditions. U.S.C. 154(b) by 0 days. This link is combined with an Ethernet network to provide high Speed digital data communication among a large num This patent is Subject to a terminal dis ber of users. In a preferred embodiment a trunk line com claimer. munication link operates within the 92 to 95 GHZ portion of the millimeter spectrum.
    [Show full text]
  • Lessons from Telco & Wireless Providers
    LESSONS FROM TELCO & WIRELESS PROVIDERS: EXTENDING THE LIFE OF THE HFC PLANT WITH NEW TECHNOLOGIES Tom Cloonan, Ayham Al-Banna, Mike Emmendorfer, Zoran Maricevic, Frank O’Keeffe, John Ulm ARRIS Group, Inc. Abstract BACKGROUND This paper draws on lessons from the past (within the telecommunications space) to Introduction predict some of the new technologies that may be considered by Multiple System Operators Correctly predicting the future is a difficult, (MSOs) as they move forward into a service but critical task for any company. This is provider world of the future. It is a future that especially true when an industry is facing a will undoubtedly demand more and more time when transitions in technologies are bandwidth to be offered to subscribers over being considered- with the potential end-of- time. life for one technology approaching and prospects for the birth of a new technology After presenting some historical data on the looming in the foreseeable future. Are there evolution of telecommunications systems and ways to extend the life of the existing some new traffic engineering information on technology? Are those extensions beneficial bandwidth growth trends, the paper will or not? If a transition is to take place, when attempt to identify the life-span of the current should it take place? Should the transition be Hybrid Fiber/Coax (HFC) infrastructure done quickly or gradually? Which through which most Voice, Video, and Data technologies should be used during the services will be provided in the future. transition? Which of many available Potential techniques for extending that life- technologies should carry the load in the span will also be explored.
    [Show full text]
  • Ethics and Operating Procedures for the Radio Amateur 1
    EETTHHIICCSS AANNDD OOPPEERRAATTIINNGG PPRROOCCEEDDUURREESS FFOORR TTHHEE RRAADDIIOO AAMMAATTEEUURR Edition 3 (June 2010) By John Devoldere, ON4UN and Mark Demeuleneere, ON4WW Proof reading and corrections by Bob Whelan, G3PJT Ethics and Operating Procedures for the Radio Amateur 1 PowerPoint version: A PowerPoint presentation version of this document is also available. Both documents can be downloaded in various languages from: http://www.ham-operating-ethics.org The PDF document is available in more than 25 languages. Translations: If you are willing to help us with translating into another language, please contact one of the authors (on4un(at)uba.be or on4ww(at)uba.be ). Someone else may already be working on a translation. Copyright: Unless specified otherwise, the information contained in this document is created and authored by John Devoldere ON4UN and Mark Demeuleneere ON4WW (the “authors”) and as such, is the property of the authors and protected by copyright law. Unless specified otherwise, permission is granted to view, copy, print and distribute the content of this information subject to the following conditions: 1. it is used for informational, non-commercial purposes only; 2. any copy or portion must include a copyright notice (©John Devoldere ON4UN and Mark Demeuleneere ON4WW); 3. no modifications or alterations are made to the information without the written consent of the authors. Permission to use this information for purposes other than those described above, or to use the information in any other way, must be requested in writing to either one of the authors. Ethics and Operating Procedures for the Radio Amateur 2 TABLE OF CONTENT Click on the page number to go to that page The Radio Amateur's Code .............................................................................
    [Show full text]