1、STANDARD Procedures for Automatic Interworking Between T.30, V.18, V.8 bis, V.8, and V.32/ Annex A Automode Modems and V.32 bis, V32,V.22 bis, V.22, V.21, V.23.212-Type and 103-Type Modems TIA-939 January 2003 TELECOMMUNICATIONS INDUSTRY ASSOCIATION Rcprmnling Ihr tclecommunica(ions industry in asso
2、cialion wilh the Elwlronic IndusInes AUiancc Elsetron ir Ind IS11 SBI 15&10 ms V.32 bis I V.32 AC or Automode V.22 bis I V.22 ANS Answering Modems USBI Figure 1 Procedure when a Calling Automode Modem Measures at least 800 ms of Signal ANS after it has Started Transmitting Signal AA Tc 3100 ms AA .
3、Automode AA Calling Modem . . . Automode ANS USBI I AC V.32 bis I V.32 Answering Modems AC V.22 bis I V.22 USBI Figure 2 Procedure when a Calling Automode Modem Measures less than 800 ms of Signal ANS after it has Started Transmitting Signal AA 9 TI A-939 ANS USBI Late-connecting Automode Calling Mo
4、dem AC Automode Automode Calling Modem AA AA 3000 f 50 ms u 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 3100 ms Late-connecting Automode Calling Modem SI1 SBI SI1 SBI SI1 SBI I 1270 Automode Calling Modem t+ 10
5、70 f 50 ms V.22 bis I V.22 ANS USBI I SI orSB1 Answering Modems 2225 I SBI 21 2-type 2225 103-type Figure 4 Procedure when an Automode Modem Calls a V.22 bis or V.22 Modem and Connects after the V.25 Answer Sequence, or Calls a 21 2-type or 103-type Modem 10 TIA-939 Calling Modems SI I SBI SBI USBI
6、USBI I SBI ANS V.22 bis v.22 103-type Automode Answering Modem 270 f 10 ms I USBI I 2225 k+ 155 f 50 ms Figure 5 Answering Automode Modem Interworking with a Calling V.22 bis, V.22 or 103-type Modem 11 TI A-939 AA 980 Hz Mark AA Automode Calling Modem USBI I AC I 1650 v.21 V.23 1300 Figure 6 Procedure when an Automode Modem Calls a V.21 Modem or a V.23 Modem Calling Modems v.21 980 Hz Mark F= 1 390 HzMark v.23 700 ms I“ 700 ms i Automode Answering USBI I AC I 1650 Figure 7 Answering Automode Modem Interworking with a Calling V.21 or V.23 Modem 12
