Patent ID: 7003225

Claim:
A method for operating a transmission system configured as a ring that uses a defined multiplexing scheme and has a plurality of connected nodes with connections in opposite directions around the ring, the method including: assigning channels for carrying traffic along connections between the nodes according to a plurality of protection classes, wherein at least one of the plurality of protection classes comprises a shared protection scheme; and assigning channels according to the shared protection scheme by: selecting M channels c 0 , (c 0 +1), . . . , (c 0 +M−1) out of N available channels and selecting n assignment groupings; for a first direction around the ring, assigning selected channels for which (c−c 0 ) mod M/n≦M/2n−1 to working traffic; and assigning selected channels for which (c−c 0 ) mod M/n>M/2n−1 to protection traffic; and for a second direction around the ring, assigning selected channels for which (c−c 0 ) mod M/n>M/2n−1 to working traffic; and assigning selected channels for which (c−c 0 ) mod M/n≦M/2n−1 to protection traffic.