臺灣博碩士論文加值系統

毫微微蜂巢式基地台是一個可以提高網絡性能並且具有短範圍、低功耗和成本效益最佳化的小型基地台。本研究最大的目標是每一個毫微微蜂巢式基地台的發射功率必須是有效的被利用。因此在跨層巨/毫微微蜂巢式基地台的網路中，減少能源消耗就變成是非常重要課題。在此研究中，毫微微蜂巢式基地台合作調整自己的發送功率，以優化在每個毫微微蜂巢式基地台的總吞吐量。因此，我們讓周圍的毫微微蜂巢式基地台能放大自身的傳輸範圍來覆蓋睡眠中的毫微微蜂巢式基地台。除了協助合作調整自己的發送功率來覆蓋睡眠中的毫微微蜂巢式基地台，還可透過本研究來節省更多的發送功率。正因為如此，當毫微微蜂巢式基地台部署的非常密集時，此研究的優點就更加顯而易見。根據模擬結果，該研究可以提高毫微微蜂巢式基地台的能源利用效率，以彌補現有研究的不足之處。

The femtocell is known as an enabler for the high data-rate transmission in future mobile ac-cess networks, due to its short-range, low-power, and cost-beneficial features. A major challenge in macro/femto-cell networks is however the efficient use of the transmission power. It is im-portant to reduce the energy consumption of the base stations for the green ICT (information and communication technology). Thus, the femtocell plays an important role to reduce the total ener-gy consumption in such a network environment. In this study, we propose a mul-ti-cell-zooming-based green handoff protocol in two-tier macrocell-femtocell network environ-ment. The main idea of the proposed protocol is to smartly enlarge the neighboring femtocells of given femto base stations (FBSs), while keeping the given femto base stations in the IDLE mode. The femto base stations can cooperatively ad-just their transmission powers to optimize the total power consumption and the impact of the transmission power on each femto base stations is addressed. Apart the neighboring femtocells can enlarge their power to keep the given femto base stations in the IDLE mode. The method also applied to power saving more transmission power. The advantage of the presented protocol is significant, especially when the deployment of femto base stations is dense. Performance results of the proposed one shown outperform than those of existing works.

1 Introduction (1)
2 Related Work (4)
2.1 Related Work (4)
2.2 Motivation (6)
3 Preliminaries (9)
3.1 System Model (9)
3.2 Problem Formulation (11)
3.3 Basic Idea (14)
4 A Multi-Cell-Zooming-Based Green Handoff Protocol (18)
4.1 Phase I: Cooperative Femtocells Selection (19)
4.2 Phase II: Cell-Zooming Calculation (22)
4.3 Phase III: Multi-Cell-Zooming-Based Handoff Decision (35)
5 Simulation Results (43)
5.1 Average Energy Consumption (44)
5.2 Average Throughput (46)
5.3 Energy Consumption Ratio (47)
5.4 Signaling Cost of Handoff (48)
5.5 Power Saving Radio (49)
6 Conclusions (51)
7 Acknowledgment (52)

[1]V. Chandrasekhar, J.G. Andrews, and A. Gatherer, “Femtocell Networks: A Survey,” IEEE Communications Magazine, vol. 46, issue. 9, pp. 59-67, September 12, 2008.
[2]G.P. Fettweis, and E. Zimmermann, “ICT Energy Consumption – Trends and Challenges,” in Proc. of International Symposium on Wireless Personal Multimedia Communications (WPMC 2008), Lapland, Finland, September, 2008.
[3]B. Wang, Y. Zhang, W. Wang, M. Lei, and L. Jiang, “A Cooperative Downlink Power Setting Scheme for CA-Based Femtocells,” in Proc. of IEEE 75th Vehicular Technology Conference Spring (VTC 2012), Yokohama, Japan, pp. 1-6, May 6-9, 2012.
[4]Y. Chen, J. Zhang, Q. Zhang, and J. Jia, “A Reverse Auction Framework for Access Permission Transaction to Promote Hybrid Access in Femtocell Network,” in Proc. of IEEE International Conference on Computer Communications (INFOCOM 2012), Orlando, USA, pp. 2761-2765, March 25-30, 2012.
[5]Small Cell Forum, http://www.smallcellforum.org, 2012.
[6]X. Wang, A.V. Vasilakos, M. Chen, Y. Liu, and T.T. Kwon, “A Survey of Green Mobile Networks: Opportunities and Challenges,” ACM Journal of Mobile Network and Applications, vol. 17, issue 1, pp. 4-20, February, 2012.
[7]Z. Niu, Y. Wu, J. Gong, Z. Yang, “Cell Zooming for Cost-Efficient Green Cellular Networks,” IEEE Communications Magazine, vol. 48, issue 11, pp. 74-79, November 4, 2010.
[8]W. Vereecken, L. Haratcherev, M. Deruyck, W. Joseph, M. Pickavet, L. Martens, and P. Demeester, “The Effect of Variable Wake Up Time on the Utilization of Sleep Modes in Femtocell Mobile Access Networks,” in Proc. of IEEE 9th Annual Conference on Wireless On-Demand Network Systems and Services (WONS 2012), Courmayeur, Italy, pp. 63-66, January 9-11, 2012.
[9]S. Zhou, J. Gong, Z. Yang, Z. Niu, and P. Yang, “Green Mobile Access Network with Dynamic Base Station Energy Saving,” in Proc. of ACM 15th Annual International Conference of Mobile Computing and Networking (MobiCom 2009), Beijing, China, pp. 10-12, 2009.
[10]A.D. Domenico, R. Gupta, and E.C. Strinati, “Dynamic Traffic Management for Green Open Access Femtocell Networks,” in Proc. of IEEE 75th Vehicular Technology Conference Spring (VTC 2012), Yokohama, Japan, pp. 1-6, May 6-9, 2012.
[11]B. Badic, T. Farrell, P. Loskot, and J. He, “Energy Efficient Radio Access Architectures for Green Radio: Large versus Small Cell Size Deployment,” in Proc. of IEEE 70th Vehicular Technology Conference Fall (VTC 2009), Anchorage, USA, pp. 1-5, September 20-23, 2009.
[12]Z. Li, S. Guo, W. Li, S. Lu, D. Chen, and V.C.M. Leung, “A Particle Swarm Optimization Algorithm for Resource Allocation in Femtocell Networks,” in Proc. of IEEE Wireless Communications and Networking Conference (WCNC 2012), Shanghai, China, pp.1212-1217, April 1-4, 2012.
[13]L.T.W. Ho, I. Ashraf, and H. Claussen, “Evolving Femtocell Coverage Optimization Algorithm using Genetic Programming,” in Proc. of IEEE 20th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC 2009), Tokyo, Japan, pp. 2132-2136, September 13-16, 2009.
[14]L. Huang, Y. Zhou, J. Hu, X. Han, and J. Shi, “Coverage Optimization for Femtocell Clusters using Modified Particle Swarm Optimization,” in Proc. of IEEE International Conference on Communications (ICC 2012), Ottawa, Canada, pp. 611-615, June 10-15, 2012.
[15]P. Jacob, and A.S. Madhukumar, “Femto-Relays: A Power Efficient Coverage Extension Mechanism for Femtocells,” in Proc. of IEEE 22nd International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC 2011), Toronto, Canada, pp. 975-979, September 11-14, 2011.
[16]M.A. Marsan, L. Chiaraviglio, D. Ciullo, and M. Meo, “Optimal Energy Savings in Cellular Access Networks,” in Proc. of IEEE International Conference on Communications Workshops (ICC 2009), Dresden, German, pp. 1-5, June 14-18, 2009.
[17]W. Zheng, T. Su, W. Li, Z. Lu, and X. Wen, “Distributed Energy-Efficient Power Optimization in Two-Tier Femtocell Networks,” in Proc. of IEEE International Conference on Communications (ICC 2012), Ottawa, Canada, pp. 5767-5771, June 10-15, 2012.
[18]B. Jeong, S. Shin, I. Jang, N.W. Sung, and H. Yoon, “A Smart Handover Decision Algorithm Using Location Prediction for Hierarchical Macro/Femto-Cell Networks,” in Proc. of IEEE Vehicular Technology Conference Fall (VTC 2011), San Francisco, USA, pp. 1-5, September 5-8, 2011.
[19]G. Yavas, D. Katsaros, O. Ulusoy, and Y. Manolopoulos, “A Data Mining Approach for Location Prediction in Mobile Environments,” ACM Journal of Data & Knowledge Engineering, vol. 54, issue 2, pp. 121-146, August, 2005.
[20]F. Aurenhammer, “Voronoi Diagrams-A Survey of a Fundamental Geometric Data Structure,” ACM Journal of Computing Surveys, New York, USA, vol. 23, issue 3, pp. 345-405, September, 1991.
[21]I. Ashraf, L.T.W. Ho, and H. Claussen, “Improving Energy Efficiency of Femtocell Base Stations via User Activity Detection,” in Proc. of IEEE Wireless Communications and Networking Conference (WCNC 2010), Sydney, Australia, pp. 1-5, April 18-21, 2010.
[22]H. Claussen, I. Ashraf, and L.T.W. Ho, “Dynamic Idle Mode Procedures for Femtocells,” Journal of Bell Labs Technical, vol. 15, issue. 2, pp. 95-116, September, 2010.
[23]Y.S. Chen, nd C.Y. Wu, “A Green Handover Protocol in Two-Tier OFDMA Macrocell-Femtocell Networks,” Journal of Mathematical and Computer Modelling, vol. 57, issue 11-12, pp. 2814-2831, June, 2012.
[24]Y.S. Chen, and S.D. Lu, “A Cell-Zooming-Based Green Handoff Protocol in Two-Tier Macrocell-Femtocell Networks,” in Proc. of Mobile Computing Workshop, August 29-30, 2012.
[25]C.E. Shannon, "A Mathematical Theory of Communication", ACM Journal of Mobile Computing and Communications, New York, USA, vol. 5, issue 1, pp. 3–55, January, 2001.
[26]The Network Simulator NS-2: http://www.isi.edu/nsnam/ns/.
[27]NIST Simulation Models for NS-2: http://www.nist.gov/itl/antd/emntg/ssm_seamlessandsecure.cfm/