Pseudo-synchronization prevention method in SDH transmission mode, pseudo-synchronization preventing SDH transmission system, and transmitter-receiver in pseudo-synchronization preventing SDH transmission system

摘要

In a terminal apparatus to which an SDH transmission mode is applied, there is a method including a pseudo-synchronization detecting step of detecting, by one transmitter-receiver, that a pseudo-synchronization state is established by finding in data the same pattern as a synchronization pattern in byte information, a pseudo-synchronization posting step of inserting, by the one transmitter-receiver, information to the effect that the pseudo-synchronization state is established in an overhead of an STM frame, and posting the information to the other transmitter-receiver, and a changed synchronization pattern transmitting step of changing a synchronization pattern into an additional synchronization pattern different from the synchronization pattern in the byte information, and transmitting the synchronization pattern obtained by the change from the other transmitter-receiver to the one transmitter-receiver. Thus, it is an object of the present invention to easily prevent pseudo-synchronization by posting the message to the effect that the pseudo-synchronization state is established to an opposite terminal apparatus by using the overhead of the STM frame such that the opposite terminal apparatus can change the synchronization pattern in the byte information.