1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 8 G0BISTELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU05“,)#G0G0$!4!G0G0.%47/2+342!.3-)33)/. G0G03).!,).G0G0!.$G0G037)4#().ii) the padding bit in the position 32 of Figure 2/X.51 bis is set to binary 1.Note - Other more complex framing patterns, which allow
2、 the use of padding bits for such functions as, forexample, housekeeping signalling or justification in the national network, are for further study.1.5 The framing strategy is for further study.1.6 The use of the framing pattern to monitor the error rate in the transmission path, which will be optio
3、nal, is forfurther study.1.7 The envelope alignment bit shall carry a pattern of alternating binary 0 and binary 1 in consecutiveenvelopes, i.e. the pattern on the A bits in Figure 2/X.51 bis can be either 010 or 101.Note - Other patterns on the A bits, e.g. “all zeros“ or “all ones“ could be used f
4、or alarm signals from thedistant end and this is for further study.1.8 The use of the status bit should comply with Recommendations X.21 and X.21 bis, together withRecommendation X.71 for connections using decentralized signalling, and with Recommendation X.60 for connectionsusing common channel signalling.
