An Optical Packet Switch with Recirculation Limited Range Wavelength Converter Groups and Recirculation Optical Buffers

This paper focuses on performances of limited range wavelength converters (LRWCs) in resolving optical packet contentions. An optical packet switch is proposed, which uses recirculation LRWC groups and recirculation fiber delay lines (FDLs) to resolve optical packet contentions. In order to make full use of the LRWCs and the FDLs, a control algorithm is also proposed. Packet loss probability of the proposed switch versus the number of FDLs, the wavelength conversion range, and the number of LRWC groups are evaluated in detail.

Analysis of Hybrid Buffering and Retransmission in OBS Networks

Burst contention is a major problem in the Optical Burst Switching (OBS) networks. Due to inadequate contention resolution techniques, the burst loss is prominent in OBS. In order to resolve contention fiber delay lines, wavelength converters, deflection routing, burst segmentation, and retransmission are used. Each one has its own limitations. In this paper, a new hybrid scheme is proposed which combines buffering and retransmission, which increases the mean number of bursts processed in the system. In this hybrid method, retransmission with controllable arrival and uncontrollable arrival is analyzed. Normally all the bursts reach the first hop and few of them go for second hop to reach destination. After all the bursts reach the destination the server may go for maintenance activity or wait for the arrival of next burst. We model it as a batch arrival single server retrial queue with buffer. Numerical results are analyzed to show the mean number of bursts processed in the system with uncontrollable arrival and controllable arrivals.