臺灣博碩士論文加值系統

IP群播目的是要有效率地將資料傳送給某一個特定群組。我們的協定建立在現有固定主機IP unicast機制上進行群播傳送的服務，並且避免掉在Mobile IP上常會出現的「三角傳遞問題」。依據現有的群播服務模型，每當在一個群播成員或資料來源地點改變時就重建傳遞樹(delivery tree)，對行動網路而言並不是一種良好的解決方式。藉由加入bi-directional tunneled群播的概念，我們的協定企圖要對群組中的其他成員隱藏主機移動的現象；此外，我們的協定又像remote subscription協定一樣擁有幾近最短的傳送路徑。我們的協定也能適應主機移動及移動成員的數目變化情形，換句話說，我們兼具了移動性與可擴充性的特點。根據我們的協定，在bi-directional tunneling方法裡會發生「通道聚合問題(tunnel convergence problem)」的現象也將被順利解決，而藉由服務範圍「R」的改變，我們可以對bi-directional tunneling與remote subscription這兩種極端方法的優缺點做出取捨，並可藉由模擬程式量測各種不同服務範圍的效能及所需付出的成本；此外，我們也將測量在不同拓樸大小下移動式主機的密度變化對於效能所造成的影響。當然要在整個網路拓樸中的群播路由器(MR)裡選取適當路由器當作MHA(multicast home agent)亦是相當重要的一項議題，因為選取不適當的MHA將會降低整體效能的表現；因此，我們使用了一套嚴謹的演算法確保在每個特定範圍內所選擇出來服務其他群播路由器(MR)的MHA數目幾乎是最少的；此外，利用距離tiebreaker與負擔tiebreakers的機制，將使群播路由器(MR)找到最適合服務它的MHA，這也將有助於整體效能的提升。最後，我們在我們的協定裡加入了Virtual Branch的概念，我們將模擬移動式主機移動handoff的情形並量測在不同的密度下對於效能及所需付出成本的影響。根據我們模擬的結果，我們相信我們的協定不用Mobile IP的方法就能夠獲得比其更好的效能。

IP multicast is an efficient means of sending to a group. Our protocol is built on top of the existing static hosts IP unicast and multicast forwarding services to avoid triangle routing which always occurs in Mobile IP. Relying only on the existing multicast service model and reconstructing the delivery tree every time a multicast member and/or source move is not always a good solution. By applying the ideas of bi-directional tunneled multicast [3], our protocol attempts to hide host mobility from all other members of the group. Therefore, the multicast distribution tree will not be updated for the sake of member location change. Furthermore, our protocol has near shortest delivery paths like remote subscription protocol [3]. Our protocol can also adapt to the fluctuation of both host movement and the number of mobile members (i.e., having mobility and scalability properties). According to our protocol, the tunnel convergence problem resulting from bi-directional tunneling will be solved. By changing service range ``R', we can trade off the advantages and disadvantages of both bi-directional tunneling and remote subscription (they are the extremes of RBMoM). We measure the system performance and cost in different service range, topology size and mobile population density through simulation. According to the results of our simulation, we believe our protocol has much better performance without using the current Mobile IP multicast solutions.

中文摘要1
ABSTRACT3
第1章導論9
1.1研究動機與簡介：9
1.1論文架構：10
第2章相關工作11
2.1行動網路的群播協定：11
2.1.1Mobile IP：11
2.1.2Mobile Multicast (MoM)：15
2.1.3IPv6：17
2.2以服務範圍為基礎下的行動網路群播系統：18
第3章行動網路群播細節23
3.1以服務範圍為基礎下的行動群播傳送機制：23
3.2MULTICAST HOME AGENT選擇演算法：27
3.3虛擬樹枝(VIRTUAL BRANCH)概念：33
第4章效能評估36
第5章結論49
參考文獻50

[1] A. Acharya, A. Bakre, and B. Badrinath, “IP Multicast Extensions for Mobile Internetworking”, Proc. INFOCOM '96, San Francisco, CA, March 1996.
[2] A. Ballardie, P. Francis, and J. Crowcroft, “Core Based Trees: An Architecture for Scalable Inter-Domain Multicast Routing”, Proceedings of ACM SIGCOMM '93, August 1993.
[3] V. Chikarmane, C.L. Williamson, R.B. Bunt and W.L. Mackrell, “Multicast Support for Mobile Hosts Using Mobile IP: Design Issues and Proposed Architecture”, ACM/Kluwer J. Mobile Networks and Applications, 3 (1998), pp. 365-379.
[4] S. Deering, D. Estrin, et al., “Protocol Independent Multicast-Sparse Mode (PIM-SM): Motivation and Architecture”, draft-ietf-idmr-pim-arch-04.ps, October 1996.
[5] S. Deering, D. Estrin, D. Farinacci, and V. Jacobson, “Protocol Independent Multicast (PIM), Dense Mode Protocol Specification”, work in progress, March 1994.
[6] S. Deering and J. Hinden, “Internet Protocol, Version 6 (IPv6) Specification”, RFC 1883, December 1995.
[7] H. Holbrook and D. Cheriton, “EXPRESS multicast: An Extended Service Model for Globally Scalable IP Multicast”, http://gregorio.standford.edu/holbrook/express/.
[8] D. Johnson, “Scalable and Robust Internetwork Routing for Mobile Hosts”, Proceedings of the 14th International Conference on Distributed Computing System, June 1994.
[9] C.R. Lin and C.-J. Chung, “A Mobile Multicast Protocol with Error Control for IP Networks”, Proceedings of IEEE GLOBECOM 2000, November 2000.
[10] C.R. Lin and K.-M. Wang, “Scalable Multicast Protocol in IP-Based Mobile Networks”, ACM/Kluwer J. Wireless Networks, Vol. 8, No. 1, pp. 27-36, January 2002.
[11] J. Moy. ``Multicast Extension to OSPF', Internet Draft, September 1992.
[12] A. Myles and C. Perkins, ``Mobile IP Extensions(MIP)', Internet Draft, October 1993.
[13] A. Mysore and V. Bharghavan, “A New Multicasting-based Architecture for Internet Host Mobility”, Proceedings of ACM/IEEE MOBICOM '97, Budapest, Hungary, September 1997.
[14] C. Perkins, “IP Mobility Support”, RFC 2002, IBM, October 1996.
[15] C. Perkins, “Mobility IP”, IEEE Communications Magazine, pp. 84-99, May 1997.
[16] C. Perkins and Y. Rekhter, “Short-cut Routing for Mobile Hosts”, Internet Draft, IBM T.J. Watson Research Center, 1992.
[17] C.L. Tan and S. Pink, “MobiCast: A multicast scheme for wireless networks”, Mobile Networks and Application 5(2000) 259-271.
[18] C-K Toh, “Crossover Switch Discovery for Wireless ATM LANs”, ACM Journal of Mobile Networks and Applications, special issue on routing in mobile communication networks, 1 (2):141-165, October 1996.
[19] D. Waitzman, C. Partridge, and S. Deering (editors), “Distance Vector Multicast Routing Protocol”, RFC 1075, BBN STC and Stanford University, November 1988.
[20] G. Xylomenos and G. C. Ployzos, “IP Multicast for Mobile Hosts”, IEEE Communications Magazine, pp. 54-58, January 1997.