Abstract: | In this paper,a novel concept of multi-granularity p-cycle is proposed.In conventional p-cycle concept,all on-cycle spans have the same capacity.However,in multi-granularity p-cycle,each on-cycle span could have different capacity.Results show that multi-granularity p-cycles are much more capacity-efficient and cost-effective than conventional p-cycles.We also propose two protection switching schemes for all types of p-cycle networks. One is wrapping protection, in which only two end nodes do real-time switching when a span failure happens.The other is steering protection,in which at most four nodes do real-time switching when a span fails.In steering protection switching scheme,the restoration path for the failure traffic demand has the least hops. |