A Pipelined Scheduling Strategy for Supporting Variable-Length Packets in WDM Networks

In single-hop star network with wavelength-division-multiplexing (WDM) technique, the packet/ wavelength assignment over a number of available channels is an important issue to provide low switching delay and high bandwidth utilization. Basically, three pipelined stages are used to service packets: collecting packets stage, scheduling packet stage and transmitting packet stage. Conventional scheduling algorithms only discuss how to find the schedule with the minimal access delay for an individual group of variable length packets regardless the pipeline feature. If the schedule of a group of packets cannot finish all transmissions before the starting time of servicing the packets of the following group, some packets will suffer extra delay. In this paper, we will propose a scheduling algorithm to overcome the potential problem by performing load balance in channels. Simulations show that the proposed balancing approach indeed can reduce the average delay and improve the load balance degree concurrently.