Abstract

In Optical Burst Switched (OBS) Networks, data is transported in a bufferless network and hence there is fair amount of possibility of contention among the data bursts. This occurs when multiple bursts contend for the same link. The existing reactive contention resolution schemes attempt to address issue of contention without making any efforts to minimize the occurrences of contention in the network. Also, the existing proactive contention minimization schemes fail to provide improvement in contention loss at a very high load. Therefore, we are presenting new scheme for reducing the occurrence of contention in OBS network and it is known as Dynamic Hybrid Cluster and Deflection Feedback (DHCF) scheme. In proposed DHCF scheme entire OBS network is partitioned into many small clusters. In each cluster, one node acts as cluster head for gathering the information of resources in the network. The contention is minimized using clustering approach and it can be further improved with the help of deflection feedback mechanism. A performance metrics is considered to evaluate merits of the proposed DHCF scheme and its effects on overall network performance. Also, the comparison of the performance of the DHCF scheme with limited hybrid deflection and retransmission (LHDR) scheme and dynamic hybrid retransmission in deflection routing (DHRD) scheme is made. The simulation results show that the proposed scheme gives improvement in Burst Loss Probability (BLP) in the range of 31% to 38% and delay improvement in the range of 64% to 74% on vBSN network. The vBSN is network topology.