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第五章 結論與未來展望
5.1 結論
Social network的興起,FaceBook、Plurk、Myspace、Twitter、Google+的盛行,近年來使 用社群網站的人數有驚人的成長。社群網站是與親朋好友相互聯繫得知消息的管道之ㄧ,
然而社群網站中的朋友可以包含學習的同儕、工作的夥伴、相同興趣或是粉絲專頁的新 朋友等。過去大家都用email分享資訊,現今社群網站可以發佈訊息、網誌、甚至是討論 話題,以上都成為分享資訊的另一種方式,可從中獲得不同消息。本論文藉由這樣的社 群關係,利用social network analysis計算且分析選出適當的轉傳節點,在網路中建立一 個較可靠的訊息轉傳方式,稱Ego-Centric Social Network Routing,簡稱ECSNR。
本篇論文模擬並比較SANE與ECSNR兩種方法,兩者出發點都是以社群為概念,當 然社群概念不單單限於朋友,也可以包含共同興趣、職業、專長等。如「ResearchGATE」
是專門給研究科學領域者一個社群網站平台,可供跨國、跨校、跨實驗室,使科學家可 以共同合作。此種概念可以將它歸納為以興趣為主要導向之社群網站,如同我們所比較 的對象SANE是以興趣導向的社群,而本論文所提出的ECSNR不但考慮了社群網站的朋 友名單,計算彼此的社會關係值,也將興趣導向之社群方法一併列入考量,以達到藉由 社會網路導向或是興趣導向將訊息傳遞至目標節點。
我們透過社會網路分析增加對訊息來源的可信度,藉由較可信的人傳送接收資訊。
本文透過𝐶𝐷_𝑑𝑖𝑣𝑒𝑟𝑠𝑖𝑡𝑦_𝑚𝑎𝑥𝑖𝑚𝑢𝑚(𝑡𝑜𝑝 (𝑛𝑢𝑚𝑏𝑒𝑟))傳送資訊,針對𝐶𝐷_𝑑𝑖𝑣𝑒𝑟𝑠𝑖𝑡𝑦_𝑚𝑎𝑥𝑖𝑚𝑢𝑚(𝑡𝑜𝑝 (𝑛𝑢𝑚𝑏𝑒𝑟))
節點負載過重提出解決方針。當節點發生負載過重時,𝑁𝑜𝑑𝑒𝑟𝑒𝑐𝑜𝑚𝑚𝑒𝑛𝑑節點幫助傳送,
其優點為讓路由中繼的位置更靠近負載過重的𝐶𝐷_𝑑𝑖𝑣𝑒𝑟𝑠𝑖𝑡𝑦_𝑚𝑎𝑥𝑖𝑚𝑢𝑚(𝑡𝑜𝑝 (𝑛𝑢𝑚𝑏𝑒𝑟))節點,加
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速訊息的傳遞。也可藉由緊密度高且較可信任之節點協助傳送。當社會網路導向無法傳 遞出去時,也可利用興趣導向方式將訊息傳遞出去。由實驗模擬結果得知,ECSNR在網 路節點數量增加時,封包送達率能有7.4%~15.8%的改善。在end to end delay有10%~15.2%
的改善,control overhead雖然較遜色,但平均依然可控制在9.4%內。Average hop count 平均能減少1.7個hops數。在網路移動速度比較的實驗,封包送達率能有8%~24.2%的改 善。Control overhead雖然較遜色,但平均仍可控制在8.8%內。End to end delay有約 4.7%~15.2%的改善。Average hop count平均能減少2.4個hops數。
5.2 未來研究
隨著網路通訊科技的發展、普及化,社群網站的服務將會是未來商業競爭的重點。研究 議題相當地廣泛,若是可以利用資料探勘擷取出相關資訊,去了解每個行動節點的獨特 性,將會是值得探討的問題,其中mining heterogeneous social networks以及dynamic social networks,都是值得進一步研究的議題。Social networks analysis and mining或許不能算 是一項全新技術,但卻是一個新潮流的技術概念,它所帶來的優勢不容小覷,在未來發 展確實精彩可期。
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參考文獻
[1] K. Fall, “A Delay-Tolerant Network Architecture for Challenged Internets,” Intel Research Technical Report IRB-TR-03-003, Feb. 2003.
[2] A. Gainaru, C. Dobre, and V. Cristea, “A Realistic Mobility Model Based on Social Networks for the Simulation of VANETs,” in Proc. Vehicular Technology Conference (VTC'09), Barcelona, Spain, pp. 1-5, Apr. 26-29, 2009.
[3] R. Lu, X. Lin, and X. Shen, “SPRING: A Social-based Privacy-preserving Packet Forwarding Protocol for Vehicular Delay Tolerant Networks,” in Proc. IEEE INFOCOM, San Diego, USA, pp. 1-9, Mar. 15-19, 2010.
[4] D. Huang, Z. Zhou, X. Hong, and M. Gerla, “Establishing Email-based Social Network Trust for Vehicular Networks,” in Proc. Consumer Communications and Networking Conference (CCNC), Las Vegas, Nevada, USA, pp. 1-5, Jan. 09-12, 2010.
[5] P. Hui, J. Crowcroft, and E. Yoneki, “Bubble Rap: Social-based Forwarding in Delay Tolerant Networks,” in Proc. ACM MobiHoc, Hong Kong, China, pp. 241-250, May.
26-30, 2008.
[6] A. Clauset, “Finding Local Community Structure in Networks,” Physical Review E, vol. 72, no. 2, Aug. 2005.
[7] A. Mei, G. Morabito, P. Santi, and J. Stefa, “Social-aware Stateless Forwarding in Pocket Switched Networks,” in Proc. INFOCOM, Calcutta, pp. 251-255, Apr. 10-15, 2011.
‧ 國
立 政 治 大 學
‧
N a tio na
l C h engchi U ni ve rs it y
79
[8] Juan Rodríguez-Covili, Sergio F. Ochoa, and Raúl Aliaga, “Extending Internet-Enabled Social Networks.” Retrieved:
http://swp.dcc.uchile.cl/TR/2011/TR_DCC-20110329-004.pdf, Oct. 2011.
[9] M. Everett and S. P. Borgatti, “Ego Network Betweenness,” Social Networks, vol. 27, no. 1, pp. 31-38, Jan. 2005.
[10] E. Daly and M. Haahr, “Social Network Analysis for Routing in Disconnected Delay-Tolerant MANETs,” in Proc. ACM MobiHoc, Sep. 2007.
[11] J.A. Barnes, “Class and Committees in a Norwegian Island Parish,” Hum Relations, vol.
7, no. 1, pp. 39-58, Feb. 1954.
[12] L. C. Freeman, “A Set of Measures of Centrality based on Betweenness,” Sociometry, vol. 40, no. 1, pp. 35-41, 1977.
[13] John Scott, Social Network Analysis: A Handbook, 2nd edition, London, Sage Publications, 2000.
[14] L. C. Freeman, Centrality in Social Networks Conceptual Clarification, Social Networks, no. 1, pp. 215-239, 1979.
[15] T. Hu, F. Hong, X. Zhang, and Z. Guo, “BiBUBBLE: Social-based Forwarding in Pocket Switched Networks,” in Proc. Ubiquitous Intelligence & Computing and 7th International Conference on Autonomic & Trusted Computing (UIC/ATC’10), Xian, Shaanxi, China, pp. 195-199, Oct. 26-29, 2010.
[16] C. E. Perkins and E. M. Royer, “Ad-hoc On-demand Distance Vector Routing,” in Proc.
IEEE WMCSA, pp. 90-100, Feb. 1999.
[17] E. Royer and C. K. Toh, “A Review of Current Routing Protocols for Ad Hoc Mobile Wireless Networks,” IEEE Personal Communications Magazine, pp. 46-55, Apr. 1999.
‧ 國
立 政 治 大 學
‧
N a tio na
l C h engchi U ni ve rs it y
80
[18] C. E. Perkins and E. M. Royer, “Highly Dynamic Destination Sequenced Distance Vector Routing (DSDV) for Mobile Computer,” in Proc. ACM Special Interest Group on Data Communication, London, UK, pp. 234-244, Sep. 1994.
[19] S. Corson and J. Macker, “Mobile Ad hoc Networking (MANET): Routing Protocol Performance Issues and Evaluation Considerations,” RFC2501. Retrieved:
http://www.faqs.org/rfcs/rfc2501.html, http://www.ietf.org/rfc/rfc2501.txt, Jan. 1999.
[20] D. B. Jhonson and D. A. Maltz, “Dynamic Source Routing in Ad Hoc Wireless Networks,” Mobile Computing, Kluwere Academic Publishers, pp. 153-181, 1996.
[21] Z. Hass and M. Pearlman, “The Performance of Query Control Schemes for the Zone Routing Protocol,” in Proc. ACM SIGCOMM, pp. 167-177, Aug. 1998.
[22] “The Network Simulator ns 2.35.” Retrieved:
http://www.isi.edu/nsnam/ns/index.html, Nov. 2011.
[23] C. Siva Ram Murthy and B. S. Manoj, Ad Hoc Wireless Networks: Architectures and Protocols, Prentice Hall PTR, 2004.