Concatenated transmission of synchronous data

Abstract

A multiplexed frame based client signal comprising a payload and a client overhead is transported between first and second client networks over a plurality of signal paths by inverse multiplexing the client signal into a plurality of lower rate signals each containing a respective payload and client overhead; attaching a carrier overhead to each said lower rate signal; transmitting the lower rate signals over the plurality of paths from the first client network to the second client network; and, at the second network, discarding the carrier overhead from each lower rate signal, and reassembling the lower rate signals so as to recover the client signal. The method enables bandwidth trading utilising virtual concatenation of synchronous optical channels, such that transparent transmission of a customers signals over any variety of intermediate networks can be achieved without requiring that the intermediate networks support virtual concatenation.