Method of monitoring the quality of digital signals in sections of a transmission line

Abstract

Abstract In a synchronous network, the quality of the transmitted digital signals is to be monitored by digital cross-connect units arranged along the link and the data obtained are to be forwarded to a centrally controlled network changeover system. <??>It is known to transmit a BIP-8 code word (bit interleaved parity 8 code) in a B3 timeslot, in the path overhead of a virtual container (VC-4) in a STM-1 signal for source-to-sink parity monitoring. This code word is now additionally transmitted in a freely available Z timeslot (Z4) of the path overhead as P4 monitoring, evaluated in each digital cross-connect unit and reinserted by the latter into the outgoing line. Since each change in the virtual container (VC-4) falsifies the B3 monitoring, a correction code word is inserted in a further Z time slot (Z5) which cancels the change due to the BIP-8 code word in the first Z timeslot (Z4). <??>This method can be used in a synchronous network wherever a virtual container (VC-4) for 149.72 Mbit/s is transmitted. <IMAGE>

Inventors

• 👤 Wolfgang Dipl.-Ing. Appelmann

Bibliographic Details