A new proposal to reduce burst contention in optical burst switching networks

In this work, we propose a mechanism to reduce the burst blocking probability in an OBS network formed by several stars interconnected by a ring. An offset windows scheme is introduced to assure that the lack of resources for a burst transmission is detected as close as possible to the ingress nodes, i.e. burst contention is only probable at the first core node of the ring that processes a control packet. The proposal guarantees that the burst transmission will be successful once the transmission has been allocated on the first link of the ring; thus, network-core resources are not wasted. Nevertheless, an additional mechanism is needed to guarantee the absence of burst losses before the reservation of resources inside the core network. A retransmission scheme and an OCDMA-based mechanism are introduced in order to achieve this objective.