Patent ID: 6870829

Claim:
A synchronous transmission apparatus for use in a synchronous transmission network in which data signals are carried on transmission paths, the data signals being arranged in container units which are arranged in data frames, each container unit being associated with respective pointer bits which indicate the position of the container unit within a respective data frame, the apparatus comprising: first and second data ports each arranged to receive a first data signal carried on a respective first and second transmission path; a path selection module, co-operable with each of said first and second data ports and arranged to select one or other of said first and second transmission paths; a third data port, co-operable with the path selection module to output data received on the selected one of said first and second transmission paths; the third data port being arranged to receive a second data signal on a respective transmission path and to communicate said second data signal to each of said first and second data ports for output thereby; and a message encoding module, arranged to determine which of said first and second transmission paths is selected, and being co-operable with said second data signal transmission path to adjust at least one of the pointer bits associated therewith to indicate said path selection; each of said first and second data ports being co-operable with the second data signal transmission path to determine the setting of said at least one pointer bit and thereby to determine which of the first and second data paths is selected.