Burst Loss Reduction Using Fuzzy-Based Adaptive Burst Length Assembly Technique for Optical Burst Switched Networks

The optical burst switching (OBS) paradigm is perceived as an intermediate switching technology prior to the realization of an all-optical network. Burst assembly is the first process that takes place at the edge of an OBS network.  It is crucial to the performance of an OBS network because it greatly influences loss and delay on such networks.  Burst assembly is an important process while  burst loss ratio (BLR) and delay are important issues in OBS.  In this paper, an intelligent burst assembly algorithm called a Fuzzy-based Adaptive Length Burst Assembly (FALBA) algorithm that is based on fuzzy logic and tuning of fuzzy logic parameters is proposed for OBS network. FALBA was evaluated against itself and the fuzzy adaptive threshold (FAT) burst assembly algorithm using 12 configurations via simulation. The 12 configurations were derived from three rule sets (denoted 0,1,2), two defuzzification techniques (Centroid [C]and Largest of Maximum[L]) and two aggregation methods (Max[M] and Sum[S]) of fuzzy logic.  Simulation results have shown that FALBA0LM has the best BLR performance when compared to its other configurations and the FAT. However, with respect to delay, FAT only outperforms all configurations of FALBA at low loads (0.0-0.4) but the performance of FAT also decreases as the load (0.4-1.0) increases. Therefore, at high loads (0.4-1.0)  FALBA2CS has the best delay performance. Our results deduce that FALBA0LM can be use

How far can we go with OBS networks

Optical Burst Switching (OBS) was proposed ten years ago as an alternative switching paradigm in order to overcome some of the drawbacks of Optical Circuit Switching (OCS). While OBS is no more necessarily perceived as a competitor to OCS, but more of a more adapted switching for networks with bursty and highly dynamic traffic, there is still a debate around OBS, i.e., how far an OBS network can go in terms of throughput with no or limited burst losses. This thesis attempts to answer this question by investigating how to devise an upper bound on the throughput of an OBS network, assuming no recourse to electrical buffering is made at any intermediate node. We investigate both the burst scheduling and routing issues, with a larger focus on routing in three directions: (i) exploration of weighted k -shortest paths, (ii) revisiting load balancing, (iii) examining tree decomposition. Simulations have been conducted to compare and evaluate each of the new ideas with adapted (with respect to throughput upper bounding) previously proposed routing algorithms on different network and traffic instances. A comparison of the best upper bound with lower bounds obtained under various assumptions is presente