Method of communicating data in communication systems

The invention pertains to a communication system (300) including one or more communication channels (10), each channel comprising a transmitter unit (20) and a receiver unit (40). Each transmitter unit (20) is connected through an optical fibre link (30) to its associated receiver unit (40). In operation, each receiver unit (20) receives payload data from its associated sending client and adds overhead data to the payload data to generate corresponding aggregate data (600). The aggregate data of each transmitter unit (20) is conveyed through the fibre link (30) to its associated receiver unit (40) which receives the aggregate data, decodes it to separate the payload data from the overhead data and then outputs the payload data to its associated receiving client. The \receiver unit (40) interprets the overhead data and uses it for controlling and managing the payload data in the system (300). The one or more channels of the system (300) are capable of adapting to the bit data rate of their associate payload data; thus, the channels are capable of operating mutually asynchronously, thereby circumventing a need for justification in the aggregate data. Moreover, each transmitter unit (20) is operable to add the overhead data to the payload data when generating the aggregate data so that the number of payload bits relative to the number of overhead bits is in a fixed ratio of 31:1. Such a fixed ratio renders the aggregate data simpler to decode and bit error rate easier to determine therefrom.