Performance analysis of adaptive multipath load balancing in WDM–LOBS networks

The rapid advances in optical transmission technology have led to a wide deployment of WDM-based networks, and OBS is considered as a promising switching technology in the optical domain.

A major problem in OBS is undoubtedly burst contention. Different mechanisms to reduce burst loss probability have been proposed, but multipath routing has many advantages and it is a relatively little explored alternative in the scope of OBS networks.

Two interesting adaptive multipath mechanisms for OBS (AARA and GPMR) have been proposed in the literature, but both of them assume that all the interfaces have total wavelength conversion capacity. However, it is expected this feature to be gradually introduced, giving rise to heterogeneous scenarios where different types of interfaces coexist.

Although AARA is applicable to heterogeneous scenarios, GPMR must be slightly modified. We propose this modification and an interesting practical implementation for GPMR. Finally, it is shown that both solutions work satisfactorily well for homogeneous scenarios, but the modified GPMR works clearly better than AARA for heterogeneous scenarios.

On the other hand, by means of a general traffic model at the burst level, and through exhaustive simulation experiments, we study the effect of the correlation structure and of the marginal distribution of the traffic arrival pattern on the burst losses.