Port modularized scheduling for OBS Network

Abstract

Optical Burst Switching (OBS) is a promising solution for next generation all-optical WDM networks. It combines the benefits of both optical packet switching and wavelength routing while taking into account the limitation of current all-optical technology. In OBS network, the user data is collected at edge node, sorted based on destination address and Qos requirement, and assembled into viable sized bursts. Prior to transmitting a burst, a control packet is created and immediately sent towards the destination in order to setup an all-optical path for its corresponding data burst (DB). In OBS network, one key factor is implementing switching nodes to achieve low DB loss rate. Another key factor in OBS network is scheduling burst packets on wavelength so as to best utilizing bandwidth. Until now, in most OBS networks, the problem of switching node architecture and scheduling algorithm are considered separately, while they are likely to interfere with each other. At the same time, all existing switching node architecture and scheduling algorithms focus only on resolving contention at local node. Even when the scheduling result may increase contention at some other nodes. In this paper, we propose a scheduling policy that combines both certain switching node architecture and scheduling algorithm. The scheduling policy will not only resolve contention at local node, but will also avoid some contention that may happen at the next-hop node. We call it port modularized scheduling policy (or PM for short).