DIGITAL DATA TRANSMITTING DEVICE FOR COMMUNICATION PATHS OF RESTRICTED AND UNRESTRICTED TRANSMISSION CHARACTERISTICS

摘要

In a digital data communication network comprising digital data transmitting and receiving devices (111, 122) and first and second digital communication paths (16, 17) connected to each other and to the transmitting and the receiving devices, respectively, a stuffing circuit (23) is controlled by a control signal producing circuit (24) so as to stuff and not to stuff an input bit sequence when at least one of the first and the second digital communication paths has a restricted transmission characteristic and when both of the communication paths have an unrestricted transmission characteristic, Preferably, necessity and unnecessity of stuffing should be detected for a leading and a trailing part of each block with a shorter interval of time than for other parts of the block, More preferably, some of binary one bits placed at the beginnings of the respective blocks are used as a part of a multiframe synchronization pattern for a signal transmitted through the communication paths.