Frame structure suitable for multiplexing signals of very different bit rate

摘要

To multiplex a fast signal with a bit sequence of 68734.375 to 68750 kbit/s with a slow signal with a bit sequence of 2048 kbit/s to form a multiplex bit stream of 71040 kbit/s, 33 bits of the fast signal are in each case combined with one bit each of the slow signal to form a sector which is repeated 248 times in the frame. The frame is preceded by 12 additional bits for signalling clock adaptations carried out and for alarm signals and after 124 sectors 12 additional bits are inserted for frame alignment so that the frame contains a total of 8456 bits with a frame period of 119.03 mu s. Of the 12 additional bits at the beginning of the frame, 5 bits are in each case used for signalling the clock adaptation for the fast and, respectively, slow signal so that the following different code words are obtained with bit interleaving of the two signalling bit groups: AO, BO: quasi-synchronous state of both signals, AO, B+: fast signal quasi synchronous, clock adaptation for slow signal, A+, BO: clock adaptation for fast signal, slow signal quasi synchronous, A+, B+: clock adaptation for both signals. <IMAGE>