1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 3 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%2!0(9!,0(!“%4)#!,G0G04%,%2!0(G0G04%2-).!,%15)0-%.4#/.$)4)/.3G0G04(!4G0G0-534G0G0“%G0G03!4)3amended at New Delhi, 1960 and Geneva, 1980)The CCITT,considering, on the one hand,(a) that the receiving portion
2、 of the sending end of the synchronous system can be linked to a start-stopreceiver operating at the nominal modulation rate of 50 bauds,unanimously declares the view(1) that the receiving portion of the sending end of the synchronous system shall satisfy the conditions laiddown for 50-baud operatio
3、n in 1.6 and 3.1 of Recommendation S.3, being understood that start-stop signals wouldbe received from a source complying with 1.1, 1.2 and 1.3 of Recommendation S.3;considering, on the other hand,(b) that the retransmitting portion of the receiving end of the synchronous system can be linked to a s
4、tart-stoptransmitter having special characteristics, because of the high speed stability of synchronous systems;unanimously declares the view(2) that the start-stop signals provided by the retransmitting portion of the receiving termination of thesynchronous system shall have the following character
5、istics:a) nominal modulation rate, 50-bauds;b) gross start-stop distortion of the signals, less than 5%;c) interval between the beginning of successive start elements, 14556milliseconds with a tolerance of 1/106.Note For a better understanding of the Recommendation, the general arrangement of a communication systeminvolving transmission over a synchronous channel is shown in Figure 1/S.12.2 Fascicle VII.1 - Rec. S.12