Burst Loss Probability Model for Hybrid Deflection and Retransmission Routing in OBS Networks

The combination of deflection routing and burst retransmission is an attractive scheme for resolving the burst contention problem in Optical Burst Switching (OBS) networks. Most of previous works on hybrid schemes use simulation approach to prove the efficicency. In this paper, we develop an analytical model for obtaining the overall burst loss ratio of an OBS network that take into account deflection and retransmission togetther. The accuracy of the proposed model is confirmed by extensive simulations upon the NS-2 simulator and two typical networks topologies. Numerical results obtained from the model indicate that at low traffic load, the hybrid scheme significantly outperforms the conventional deflection routing and burst retransmission schemes in terms of overall burst loss ratio. However, at high traffic load, the simple hybrid scheme performs even worse than the other schemes.