The Design Of The Edge Node Of Synchronous OPS Networks

The Optical Packet Switch (OPS) became one of the most important technical of optical network because of its advantage of great bandwidth and flexibility.The paper contains two parts of research: the software and hardware. The research of software focuses on the assembling algorithm for edge node of synchronous OPS network and a new assembling algorithm is proposed in the paper. The research of hardware is about the development of the Ethernet circuit board for the edge node of synchronous OPS.There is much research on the assembling algorithm in OPS and OBS networks, but all of these algorithms are for the no_length_limit assembling process. The optical packet in the synchronous OPS network is length_limit and in order to make sure each optical packet has the same length, useless data has to be filled into the optical packet, which will reduce the utilization of bandwidth. Based on this character and the self-similar input stream, a new assembling algorithm, AFL (Adaptive Algorithm for Fixed Length Assembling), is proposed in the paper. By adaptively adjusting the parameters for the assembling, AFL algorithm improves the performance of the assembling process, as well as the bandwidth utilization.The research of hardware contains two parts: the design of the circuit board and the development of the program for the FPGA on the circuit board. The circuit board is responsible for transfer/receiving Ethernet frames and assembling/un-assembling optical packets by AFL algorithm. Three main chips are used on the circuit board: Intel82545 MAC, PCI9656, and Cyclone II FPGA. The RS232 interface, which is connected to the PC, is used while debugging the program for the FPGA.