1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 2 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%2!0(94%,%2!0(G0G042!.3-)33)/.4/,%2!“,%G0G0,)-)43G0G0 amended at Geneva, 1976 and 1980)The CCITT,considering(a) that, to facilitate the study of plans for the establishment of international telegraph circu
2、its, it is convenientto set limits for the degree of isochronous distortion of the telegraph circuits and channels;(b) that, for whatever purpose normally used, these circuits should be capable of use with start-stop equipment;(c) that, in certain cases, limits have been set by Recommendations R.57
3、and R.58 for the isochronousdistortions of the trunk sections of circuits and for that of voice-frequency telegraph channels;(d) that the limits laid down are those that should be evident in service conditions on telegraph circuits,excluding the local lines and terminal equipment,unanimously declare
4、s the view(1) that circuits (excluding local lines and terminal equipment) should be established and maintained in such amanner that the degree of isochronous distortion will not exceed 28% whether they are equipped with regenerativerepeaters or not;(2) that the degree of isochronous distortion of each channel that may form part of a circuit should be as smallas possible, and should not in any case exceed 10 %.
