| Summary: | 博士 === 國立臺灣科技大學 === 電子工程系 === 91 === With the proliferation of real-time audio and video applications shared by multiple users on the Internet, the importance of multicast QoS routing increases dramatically. Many existing IP multicast routing protocols are mature enough to be standardized but they still cannot support guaranteed quality of service and their performance are still doubted. Some newly proposed QoS-aware approaches can overcome this issue but there still are many problems such as favoring bias to specific group density population, constructing poor multicast delivery tree and long routing latency that suffers in highly dynamic environment, and the scalability problem in terms of both communication and storage overhead incurred by global advertising scheme.
In this dissertation, four efficient strategies are proposed to address those issues in the field of dynamic IP multicast QoS routing protocols. First, we propose a density sensitive approach named DSDMR, which relies on the scheme of adaptive bi-direction search to overcome the problem of favoring bias to specific group density. Second, a temporal-correlated T-TBP approach is designed to improve the total cost of multicast delivery tree, which is constructed by non-arrangement Steiner tree based approaches, via path caching and route adjustment techniques. Both the DSDMR and T-TBP approaches belong to the class of on-demand based scheme, which has the strengths of constructing feasible multicast tree via the most up-to-date information, and more scalable in terms of modest communication overhead and negligible storage overhead. However, the disadvantage of long routing latency make the on-demand based scheme hard to adapt to frequently changed membership. The precomputation-based approach can overcome this problem but needs to sacrifice both communication and storage overhead. To conjoin the benefits of both kinds of approaches, we propose a hybrid approach named PPMRP protocol based on the schemes of scope-limited advertisement and probabilistic selection of precomputation routers. Furthermore, another attempt called MQOSPF is also proposed, which is a very simple multicast extension of the well-known precomputation-based unicast QoS routing protocol named QOSPF.
Recently, there are many multicast QoS routing algorithms, which strive to efficiently compute feasible multicast delivery tree, have been proposed. However, from protocol aspect, some other important concerns including both routing performance and routing overhead need to be taken into account. To demonstrate the benefits of our proposals, we compare those proposals with some newly proposed multicast QoS routing protocols. Both performance and overhead for all those protocols are evaluated through the extensive simulations.
|
|---|
