1、EIA/TIA STANDARD Procedures for Automatic Interworking Between Automode Modems and Modems Conforming to Recommendations V.32, 1.22biS, and v.22. EIA/TIA/IS-63 AUGUST 1990 ELECTRONIC INDUSTRIES ASSOCIATION ENGINEERING DEPARTMENT EIA TIA/IS-b3 90 W 3234600 0030728 3 W b NOTICE EIA/TIA Engineering Stan
2、dards and Publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for h
3、is particular need. Existence of such Standards and Publications shall not in any respect preclude any member or nonmember of EIA/TIA from manufacturing or selling products not conforming to such Standards and Publications, nor shall the existence of such Standards and Publications preclude their vo
4、luntary use by those other than EIA/TIA members, whether the standard is to be used either domestically or internationally, Recommended Standards and Publications are adopted by EIA/TIA without regard to whether their adoption may involve patents on articles, materials, or processes. By such action,
5、 EIA/TIA does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the Recommended Standard or Publication. This EIA/TIA Interim Standard was developed by the TR-30.1 Subcommittee on Modems. EIA/TIA INTERIM STANDARDS EIA/TIA Interim Standards c
6、ontain information deemed to be of technical value to the industry, and are published at the request of the originating Committee without necessarily following the rigorous public review and resolution of comments which is a procedural part of the development of an EIA/A Recommended Standard. EIA/TI
7、A Interim Standards should be reviewed on an annual basis by the formulating Committee and a decision made on whether to proceed to develop an EIA/TIA Recommended Standard on this subject. EIA/TIA Interim Standards must be cancelled by the Committee and removed from the EIA/TIA Standards Catalog bef
8、ore the end of their fifth year of existence. Published by ELECTRONIC INDUSTRIES ASSOCIATION Engineering Department 2001 Pennsylvania Avenue N.W. Washington, D.C. 20006 PRICE: 11.00 COPYRIGHT 1990 TELECOMMUNICATIONS INDUSTRY ASSOCIATION All rights reserved Printed in U.S.A. EIA TIA/IS-b3 90 3234600
9、0010729 3 W EIA/TIA/IS-63 PROCEDURES FOR AUTOMATIC INTERWORKING BETWEEN AWTOMODE MODEMS AND MODEMS CONFORMING TO RECOMMENDATIONS V.32, V.22BIS, AND V.22. a PREFACE This standard has been prepared to assist manufacturers in the design of modems which can inter- work with a variety of other modems adh
10、ering to different modulation standards. The techniques presented in this standard are based on the techniques presented in the CCIT recommendation V.32 Annex A. The material contained in this standard was formulated under the cognizance of TIA committee IR-30.1. i - EIA TIA/IS-b3 90 W 3234b00 OOLO7
11、30 T 1. SCOPE EIA/TIA/IS-63 Page I 1.1 General This standard specifies a procedure for a modem to automatically detect the modulation technique and data signalling rate of the modem it is connected with. When incorporated into a new modem, which has the capability of using multiple modulation techni
12、ques, this procedure will allow for au- tomatic interoperation. It specifies: Section 1 - Scope Section 2 - Related Standards Section 3 - Terms Section 4 - Procedures 1.2 Modulation Techniques and Data Signalling Rates Modems incorporating the modulation techniques and data signalling rates of CCI“
13、Recommen- dations V.32, V.22 bis, and V.22 are addressed in this standard. 1.3 Mode of Operation (9 This standard addresses both the cases where the modem, incorporating this procedure, is the orig- inating as well as the answering modem. Late-connecting modem operation is also addressed. EIA TIA/IS
14、-b3 90 W 3234600 OOLO73L I m EI A/TI A/ I S-63 Page 2 2. APPLICABLE DOCUMENTS AND STANDARDS 8 Recommendation V.22 - 1200 bitsper second duplex modem standardized for use in the general switched telephone network and on point-to-point 2-wire leased telephone type circuits. Recommendation V.22 bis- 24
15、00 bits per second duplex modem, using a frequency division tech- nique, standardized for use in the general switched telephone network and on point-to-point 2-wire leased telephone type circuits. Recommendation V.25 - Automatic answering equipment and/or parallel automatic calling equip- ment on th
16、e general switched telephone network including procedures for disabling echo control devices for both manually and automatically established calls. Recommendation V.32 - A family of 2-wire, duplex modems operating at data signalling rates of up to 9600 bits per second for use on the general switched
17、 telephone network and leased telephone type circuits. EIA TIA/IS-b3 90 3234600 0010732 3 E EIA/TIA/IS-63 Page 3 3.1 Definitions Automode Modem - A m 3. TERMS dem incorporating multiple modulation techniques and signalling rates capable of automatically detecting the capabilities of the modem it is
18、connected with and switching to the appropriate combination to allow interworking at the highest possible signalling rate. Low Channel - The channel with a 1200 Hz carrier frequency specified in CCITI Recommenda- tion V.22 bis. Late Connecting - An originating modem which connects to the line too la
19、te to detect answer tone, or a V.32 modem which does not respond to answer tone. Calling Tone - An interrupted tone transmitted from the calling end as specified in CCI“ Recom- mendation V.25. 3.2 Abbreviations ANS - The 2100 Hz answer tone as specified in CCI?T Recommendation V.25. USB1 - A signal
20、consisting of repeated unscrambled binary 1 as specified in CCIIT Recommen- dation V.22 bis. SB 1 - A signal consisting of repeated scrambled binary 1 as specified in CCI“ Recommendation V.22 bis. S 1 - A signal consisting of unscrambled double dibit O0 and 11 as specified in CCITI Recommen- dation
21、V.22 bis. AA - A signal consisting of repetitive signal states A as defined in CCIIT Recommendation V.32, Table 1 and Figure 1. AC - A signal consisting of alternating signal states A and C as defined in CCITI Recommendation V.32, Table 1 and Figure 1. EIA TIAIIS-63 90 m 3234b00 0010733 5 m EIA/TIA/
22、ISB3 Page 4 4, PROCEDURES 4.1 Calling Automode Modem On connection to the line the calling automode modem shall initially remain silent or optionally transmit calling tone as per recommendation V.25, and condition its receiver to detect any of the following signals: AC, USBl or ANS. 4.1.1 Detection
23、of Signal AC - V.32 or Automode Answering Modem If signal AC is detected the automode modem shall begin transmission of signal AA and proceed with the start-up procedures specified in CCI“ Recommendation V.32, paragraph 5.4.1. 4.1.2 Detection of Signal USB 1 If signal USB 1 is detected the automode
24、modem shall start a 1600 ms timer. 4.1.2.1 V.22N.22 bis Answering Modem If USBl is still present when the timer expires the automode modem shall proceed with the inter- working procedures specified in CCIT Recommendation Y22 bis, paragraph 6.3.1.1. 4.1.2.2 V.32 or Automode Answering Modem If signal
25、AC is detected prior to the expiration of the timer the auotomode modem shall proceed with the start-up procedures specified in CCIT Recommendation V.32 paragraph 5.4.1. 4.1.3 Detection of Signal ANS If signal ANS is detected for a period of at least 1 second, the automode modem shall send signal AA
26、, condition its receiver to detect either signal USB 1 or signal AC, and start a timer. The timer shall be stopped when signal ANS is no longer detected. 4.1.3.1 Subsequent Receipt of AC Signal If after signal ANS has stopped and the 75 f 20 ms silent period expires, signal AC is detected, the autom
27、ode modem shall proceed with the start-up procedure as specified in CCIIT Recommenda- tion Y32 paragraph 5.4.1. 4.1.3.2 Subsequent Receipt of USBl After Greater than 800 ms of Signal ANS If signal USB 1 is detected for 155-t-10 ms, and the timer value is greater than 800 ms, the automode modem shall
28、 stop transmitting signal AA, wait 456 ms, then proceed with the interworking proce- dures as defined in CCI?T Recommendation V.22 bis, paragraph 6.3.1.1 4.1.3.3 Less than 800 ms of Signal ANS If the timer value is less than 800 ms, the automode modem shall proceed as specified above in Section 4.1.
29、2. 4 EIA TIA/IS-63 90 m 3234600 0010734 7 m EIA/TIA/ISS3 Page 5 4.2 Answering Automode Modem On connection to the line, the answering automode modem shall transmit ANS in accordance with the procedures specified in CCIT Recommendation V.25, Section 4, and condition its receiver to detect signal AA.
30、4.2.1 Signal AA Detected - V.32 or Automode Calling Modem If signai AA is detected during the answer sequence as specified in CCITT recommerldation V.25, Section 4, the automode modem shall proceed with the start-up procedures specified in CCITT Recommendation V.32, paragraph 5.4.2. 4.2.2 Signal AA
31、not detected If signal AA is not detected during the Recommendation V.25 answering sequence, the answering automode modem shall transmit signal USB1, condition its receiver to detect, in the low channel, signals S 1 or SB 1 and start a 1500 f 50 ms timer. NOTE: Some V.32 modems may not be designed t
32、o accommodate USB 1 signals that have a dura- tion greater than 294 ms (see CCIT Recommendation V.32, paragraph 5.4.2, Note 2). 4.2.2.1 S 1 or SB 1 Detected before Expiration of the Timer If either signals S1 or SB1 are detected before the timer expires, the automode modem shall pro- ceed with the i
33、nterworking procedures as specified in CCIIT Recommendation V.22 bis, paragraph 6.3.1.1.2 b). 4.2.22 Expiration of 1500 ms Timer before Detecting any Signals If the timer expires before signals S 1 or SB 1 are detected, the automode modem shall proceed with the start-up procedures specified in CCIIT
34、 Recommendation V.32, paragraph 5.4.2. EIA TIA/IS-b3 - 90 m USB 1 V.22 bis I V.22 3234600 Answering Modems m - AC V.32 - USB 1 V.22 bis I V.22 EIA/TIA/IS-63 Page 6 Figure 1 Procedure when a Calling Automode Modem Measures at least 800 ms of Signal ANS after it has Started Transmitting Signal AA Tc16
35、00ms 1-1 1 AA *. . AA K I AC Au tomode ANS USB1 C Figure 2 Procedure When a Calling Automode Modem Measures less than 800 ms of Signal ANS after it has Started Transmitting Signal AA Y+- , s EIA TIA/IS-b3 90 m 3234b00 0010736 O m 3 EIA/TI A/ IS-63 Page 7 Automode Calling I Modem AA Late-connecting A
36、utomode Calling Modern J AA 1500 f 50 ms - ANS USB1 AC Automode - AC V.32 Answering Modems Figure 3 Procedure when an Automode Modem Calls another Automode Modem or a V.32 Modem and Connects after the V.25 Answer Sequence Tc 16oO ms s1 SB1 Automode - ANS USB 1 S1 or SB1 V.22 bis i V.22 Late-connecti
37、ng Automode Calling Modem Answering Modem Figure 4 Procedure when an Automode Modem Calls a V.22 bis or V.22 Modem and Connects after the V.25 Answer Sequence EIA TIA/IS-b3 90 m - 3234b00 0030737 _ s1 SB1 V.22bis EI A/TI A/ I S-63 Page 8 SB 1 v.22 Automode SI 1 SBl ANS USB1 Figure 5 Answering Automode Modem Interworking with a Calling V.22 bis orV.22 Modem k 8
