Loss Minimization and Delay Differentiation for Optical Burst Switching Over Star Networks

Abstract

In OBS networks, lost bursts can be recovered proactively using burst cloning, or reactively using burst retransmission. Burst cloning has advantage of low delay but it suffers from low throughput. Burst retransmission has advantage of high throughput but at the cost of high delay. To minimize delay while keeping high throughput in star OBS networks, we propose three schemes: (1) enhanced burst retransmission scheme that controls the retransmissions; (2) hybrid loss recovery scheme that integrates efficiently burst cloning and burst retransmission; (3) differentiated QoS scheme that provides differentiation between two classes in terms of delay using burst cloning and burst retransmission. Both analytical and simulation results show that the proposed schemes achieve high throughput. We find that, compared to basic burst retransmission scheme, first scheme reduces delay only at moderate and high load, however, second and third scheme reduce delay at every load. Third scheme can also give good differentiation.