P2P傳輸協定應用於多媒體串流，可以均衡節點負載並且讓使用者在網路上觀賞影片獲得良好的播放品質。多媒體串流的最佳化可以分為:(1)片段選取: 藉由時間迫切性與片段稀有性獲得適當下載片段優先權，所以服務節點皆能擁有使用者需求的片段。(2)負載平衡: 平衡各節點的負載度，讓服務節點的上傳頻寬皆能滿足影片的播放速率。

在現實的P2P網路環境中，鄰居節點不一定能給予使用者所需的檔案片段。為了符合現實網路的環境設定，相對於完美鄰居節點環境，本文假設鄰居節點可能無法提供缺乏的檔案片段給使用者，所以節點對於缺乏的片段採用泛播式詢問方法獲得候選服務節點。並且分析選取服務節點策略之後，配合LE(Loading Evaluation)評價機制促進節點負載平衡。

經由模擬的方式，在相同的網路架構中使用節點的下載速率以及緩衝時間做為評估基準。LE機制能藉由準確的評價服務節點負載，有效提升下載速率並且減緩緩衝時間以及次數，改善系統下載效益。

P2P technologies are often employed in multimedia streaming systems to balance communication load of nodes and improve streaming quality. The optimization of multimedia streaming generally contains two aspects, chunk selection and load balancing. The former decides the priority of data chunks to request based on their urgency and rarity, while the latter distributes traffic loads among peers without compromising playback performance.

In contrast with prior approaches, this thesis considers a more realistic network environment where neighboring peers cannot always provide require data. This thesis proposes a new evaluating metric for nodes to select servicing peers.

Simulation results show that in terms of the bandwidth usage and the buffering situation, the new metric successfully improves the download efficiency and reduces total buffing time and buffering counts under different peer selecting schemes.

A. Habib and J. Chuang, "Service di erentiated peer selection: an incentive
mechanism for peer-to-peer media streaming," Proceedings of the IEEE Trans-
actions on Multimedia, vol. 8, pp. 610-621, June 2006.

BitTorrent, "http://www.bittorrent.com"

J. Kubiatowicz, D. Bindel, Y. Chen, S. Czerwinski, P. Eaton, D. Geels,
R. Gummadi, S. Rhea, H. Weatherspoon, W. Weimer, C. Wells, and B. Zhao,
"Oceanstore: An architecture for global-scale persistent storage," Proceeedings
of the Ninth International Conference on Architectural Support for Program-
ming Languages and Operating Systems, pp. 190-201, 2000.

D. P. Anderson, J. Cobb, E. Korpela, M. Lebofsky, and D. Werthimer,
"Seti@home: An experiment in publicresource computing," Proceedings of the
ACM on Communications, vol. 45, no. 11, pp. 56{61, 2002.

I. Stoica, R. Morris, D. Liben-Nowell, D. R. Karger, M. F. Kaashoek, F. Dabek,
and H. Balakrishnan, "Chord: a scalable peer-to-peer lookup protocol for in-
ternet applications," IEEE/ACM Trans. Netw., vol. 11, no. 1, pp. 17-32, 2003.

B. Y. Zhao, L. Huang, J. Stribling, S. C. Rhea, A. D. Joseph, and J. K. D.,
"Tapestry: a resilient global-scale overlay for service deployment," Proceedings
of the IEEE Journal on Selected Areas in Communications, vol. 22, pp. 41-53,
Jan. 2004.

A. I. T. Rowstron and P. Druschel, "Pastry: Scalable, decentralized object
location, and routing for large-scale peer-to-peer systems," Proceedings of the
IFIP/ACM International Conference on Distributed Systems Platforms Heidel-
berg, pp. 329-350, 2001.

Gnutella, "http://www.clip2.com"

P. Golle, K. Leyton-Brown, and I. Mironov, "Incentives for sharing in peer-to-
peer networks," Proceedings of the ACM Electronic Commerce, Oct. 2001.

D. A. Turner and K. W. Ross, "A lightweight currency paradigm for the p2p
resource market," Proceedings of the 7th International Conference on Electronic
Commerce Research, 2004.

S. C. Vivek Vishnumurthy and E. G. Sirer, "Karma: A secure economic frame-
work for peer-to-peer resource sharing," Proceedings of the ACM SIGCOMM
Workshop Economics of Peer-To-Peer Systems, 2003.

R. T. B. Ma, S. C. M. Lee, J. C. S. Lui, and D. K. Y. Yau, "A game theo-
retic approach to provide incentive and service di erentiation in p2p networks,"
Proceedings of the ACM SIGMETRICS, 2004.

B. Y. H. GarciaMolina, "Ppay: micropayments for peer-to-peer systems," Pro-
ceedings of the 10th ACM conference on Computer and Communications Secu-
rity, pp. 300-310, 2003.

W. Wang and B. Li, "Market-driven bandwidth allocation in sel sh overlay
networks," Proceedings of the Annual Joint Conference of the IEEE Computer
and Communications Societies, vol. 4, pp. 2578-2589, March 2005.

G. Tan and S. Jarvis, "A payment-based incentive and service di erentiation
scheme for peer-to-peer streaming broadcast," Proceedings of the IEEE Trans-
actions on Parallel and Distributed Systems, vol. 19, pp. 940-953, July 2008.

M. Gupta, P. Judge, and M. Ammar, "A reputation system for peer-to-peer
networks," Proceedings of the 13th Int. Workshop on Network and Operating
Systems Support for Digital Audio and Video, pp. 144-152, 2003.

KaZaA, "http://www.kazaa.com"

E. P. Lazear and S. Rosen, "Rank-order tournaments as optimum labor con-
tracts," Journal of Political Economy, vol. 89, no. 5, pp. 841-864, 1981.

Y. hua Chu and H. Zhang, "Considering altruism in peer-to-peer internet
streaming broadcast," Proceedings of the 14th International Workshop on Net-
work and Operating Systems Support for Digital Audio and Video, pp. 10-15,
2004.

Y. H. Chu, J. Chuang, and H. Zhang, "A case for taxation in peer-to-peer
streaming broadcast," Proceedings of the ACM SIGCOMM Workshop on Prac-
tice and Theory of Incentives in Networked Systems, pp. 205-212, 2004.

S. H. Dongyan Xuy, Mohamed Hefeeda and B. Bhargava, "On peer-to-peer
media streaming," Proceedings of the 22nd International Conference on Dis-
tributed Computing Systems, pp. 363-371, 2002.

B. Cohen, "Incentives build robustness in bittorrent," Proceedings of the 1st
Workshop on Economics of Peer-to-Peer Systems, 2003.

J. C. L. Bridge Q. Zhao and D.-M. Chiu, "Exploring the optimal chunk se-
lection policy for data-driven p2p streaming systems," Proceedings of the 9th
International Conference on Peer-to-Peer Computing, 2009.

Y. Zhou, D. M. Chiu, and J. C. S. Lui, "A simple model for analyzing p2p
streaming protocols," Proceedings of the IEEE International Conference on
Network Protocols, pp. 226-235, 2007.

N. Parvez, C. Williamson, A. Mahanti, and N. Carlsson, "Analysis of bittorrent-
like protocols for on-demand stored media streaming," SIGMETRICS Perform.
Eval. Rev., vol. 36, no. 1, pp. 301-312, 2008.

M. I. Aggelos Vlavianos and M. Faloutsos, "Bitos: Enhancing bittorrent for sup-
porting streaming applications," Proceedings of the IEEE International Con-
ference on Computer Communications., pp. 1-6, April 2006.

T. Z. J. F. Yongzhi Wang and D.-M. Chiu, "Analysis of load balancing algo-
rithms in p2p streaming," Proceedings of the Annual Allerton Conference on
Communication, Control, and Computing, pp. 960-967, Sept. 2008.

D. L. Eager, E. D. Lazowska, and J. Zahorjan, "Adaptive load sharing in ho-
mogeneous distributed systems," Proceedings of the IEEE Trans. on Software
Eng., vol. 12, no. 5, pp. 662-675, 1986.

M. Mitzenmacher and A. W. Richa, "The power of two random choices: A sur-
vey of techniques and results," Handbook of Randomized Computing, pp. 255-
312, 2000.

P. Version, M. Adler, S. Chakrabarti, M. Mitzenmacher, and L. Rasmussen,
"Parallel randomized load balancing," Proceedings of the ACM Symposium on
Theory of Computing, pp. 119-130, 1995.

K. Suh, C. Diot, J. Kurose, L. Massoulie, C. Neumann, D. Towsley, and
M. Varvello, "Push-to-peer video-on-demand system: Design and evaluation,"
Proceedings of the IEEE Journal on Selected Areas in Communications, vol. 25,
pp. 1706-1716, December 2007.

M. Xu and J. Guan, "Routing based load balancing for unstructured p2p net-
works," Future Generation Communication and Networking, vol. 2, pp. 332-
337, Dec. 2007.

Z. Li and G. Xie, "A distributed load balancing algorithm for structured p2p
systems," Proceedings of the 11th IEEE Symposium on Computers and Com-
munications, pp. 417-422, June 2006.

B. Godfrey, K. Lakshminarayanan, S. Surana, R. Karp, and I. Stoica, "Load
balancing in dynamic structured p2p systems," Proceedings of the Twenty-third
AnnualJoint Conference of the IEEE Computer and Communications Societies,
vol. 4, pp. 2253-2262, March 2004.

V. Pai, K. Kumar, Kapil andTamilmani, V. Sambamurthy, and A. E. Mohr,
"Chainsaw: Eliminating trees from overlay multicast," Peer-to-Peer Systems
IV, pp. 127-140, 2005.

M. Castro, P. Druschel, A.-M. Kermarrec, A. Nandi, A. I. T. Rowstron, and
A. Singh, "Splitstream: High-bandwidth content distribution in cooperative
environments," Proceedings of the 2nd International Workshop on Peer-to-Peer
Systems, 2003.

J. Li, "Peerstreaming: A practical receiver-driven peer-to-peer media streaming
system," tech. rep., Technical report, Microsoft Research MSR-TR-2004-101,
2004.

B. L. Xinyan Zhang, Jiangchuan Liuy and T.-S. P. Yum, "Coolstreaming/-
donet: a data-driven overlay network for peer-to-peer live media streaming,"
Proceedings of the Annual Joint Conference of the IEEE Computer and Com-
munications Societies, vol. 3, pp. 2102-2111, 2005.