| To support IP traffic over WDM networks, optical burst switching (OBS) is emerging as a viable technology for transporting bursty IP traffic over WDM networks. However, OBS has two overheads, i.e., control packets and guard bands, and it is desirable to reduce those overheads for efficient transport of traffic. On the other hand, multicasting is increasingly becoming popular due to a rapid increase of multimedia applications. In this research, we study multicast problems at the WDM layer in OBS WDM networks under the framework of Multiprotocol Label Switching.; We study three multicast schemes for efficient transport of multicast bursts: Separate Multicasting, Multiple Unicasting, and Tree-Shared Multicasting. For Tree-Shared Multicasting, we propose three tree sharing strategies, namely Equal Coverage (EC), Super Coverage (SC), and Overlapping Coverage (OC). We develop centralized shared multicast tree construction algorithms in order to deliver bursts for TreeShared Multicasting with the OC strategies. Relative performance is evaluated for three multicast schemes using simulations and a simple analysis under static sessions and membership with unlimited bandwidth per link.; WDM multicast must support dynamic sessions and membership as in IP multicast. We study efficient regrooming algorithms for supporting Tree-Shared Multicasting with dynamic sessions and membership. We perform simple analyses, and show that Tree Shared Multicasting can achieve not only bandwidth savings, but also a lower burst loss probability using simulations.; Since the bandwidth savings in Tree-Shared Multicasting depend on how efficient shared tree can be constructed, we propose efficient distributed shared tree construction protocols. For performance comparison, we also construct an optimal shared tree modeled as Steiner Minimal Tree. We evaluate and analyze the proposed protocols in terms of the cost of shared tree, message complexity, and convergence time using simulations.; Due to a potentially high burst loss probability in OBS networks, we propose an efficient reliable multicast protocol at the WDM layer for efficiency reasons such as detection time and recovery latency. To achieve a fast, efficient recovery, and high bandwidth utilization for a lost burst, we add two functions to optical WDM switch: subcasting and maintaining bursts states. We evaluate performance using simulations and show its effectiveness. |
