在長程演進技術升級版中，為了解決訊號涵蓋範圍死角及人口密集處通訊品質不佳的問題，第三代合作夥伴計畫提出異質網路架構來改善此問題，透過布建成本較低、功率較小的小型基地台來增強訊號品質不佳的環境；另外為了平衡系統的負載，第三代合作夥伴計畫提出利用細胞範圍延伸機制來增加微微型基地台的服務用戶數，以及改善細胞邊緣與整體系統的效能。
許多文獻已經針對此問題進行探討，但皆以用戶分布的情境的角度作探討，接著根據此分布情境去計算整體系統的效能，並觀察有何變化，由於實際上用戶的分布會隨著時間變化而改變，各基地台所需服務的用戶數也會跟著改變，因此本論文改以利用基地台服務用戶比例的角度作探討，相較於利用用戶分布情境，基地台服務用戶比例更能夠隨著環境的變化靈活分配各基地台的服務用戶，並且藉由此方法改善整體系統效能以及找出最佳的整體系統效能。
其模擬結果顯示，本論文提出的利用基地台服務用戶比例搭配細胞範圍延伸機制的方法儘管改善幅度較不明顯，但能有效改善整體系統效能，以及找出最佳整體系統效能，並得知各個基地台的服務用戶比例。

In the long term evolution advanced （LTE-A）, Third Generation Partnership Project （3GPP） presented heterogeneous network to improve the signal coverage and communication quality, by placing lower power base stations to enhance signal quality. Besides, to balance system loading, 3GPP also proposed Cell Range Extension （CRE）, increasing the number of serving user from pico base stations.
Since many documents have been discussed over this topic, but all these documents were viewed an issue from a user distribution perspective and then used these distribution to calculate overall system efficiency. This paper is discussed over proportion of serving users, compared to the situation with the user distribution perspective, this paper’s disposal is more flexible as circumstances change can assign service users each base station, and by this way to improve overall system performance and to identify the best overall system performance.
The simulation results from disposal show that the proportion of users of the serving base station. Despite improved margin less obvious, but can improve overall system performance, also can identify the best overall system performance and the proportion of serving users base station.

[1] 3GPP, Overview of 3GPP Release 8 V0.2.3.
[2] 3GPP TSG RAN WG1:”Evolved Universal Terrestrial Radio Access（E-UTRA）,Physical Channels and Modulation （Release 11）”,3GPP TS36.211,Dec.2012
[3]D.Erik,P.Stefan and S.Johan.（2011） ”4G LTE/LTE-Advanced for Mobile Broadband”.Academic Pr
[4]3GPP TS 36.300, “Evolved Universal Terrestrial Radio Access （E-UTRA） and Evolved Universal Terrestrial Radio Access Network （E-UTRAN）,” Rel. 10, v10.2.0, Dec. 2010.
[5] “在3G與LTE的異質網路下多重無線存取技術整合之評估”[online],Journal of Computer Science and Educational Technology 2012 Vol.2 No.1
Available: http://jcset.mcu.edu.tw/papers/Vol2_No1/02007.pdf
[6]“3GPP LTE-Evolved UTRA-Radio Interface Concepts”[online].
Available:http://ecee.colorado.edu/~ecen4242/LTE/radio.htm
[7] ”Long Term Evolution”[online].
Available:http://shishireahmed.blogspot.tw/2010_06_01_archive.html
[8]Qualcomm Incorporated,”LTE Advanced:Heterogeneous Networks,”January,2011
[9] Damnjanovic, A.; Montojo, J.; Yongbin Wei; Tingfang Ji; Tao Luo; Vajapeyam, M.; Taesang Yoo; Osok Song; Malladi, D., "A survey on 3GPP heterogeneous networks," Wireless Communications, IEEE , vol.18, no.3, pp.10,21, June 2011
[10] wikipedia [online] Available:http://en.wikipedia.org/wiki/Picocell#cite_note-1
[11] ”Latest news and information on 3G, 4G and 5G wireless technologies”,[online]Available:http://blog.3g4g.co.uk/2013/04/cell-range-expansion-cre.html
[12] Ching-Hao Huang; Chen-Yin Liao, "An interference management scheme for heterogeneous network with cell range extension," Network Operations and Management Symposium （APNOMS）, 2011 13th Asia-Pacific , vol., no., pp.1,5, 21-23 Sept. 2011
[13] Fengming Cao; Sooriyabandara, M.; Zhong Fan, "Downlink Spectrum Allocation for Macro-Femto Networks," Vehicular Technology Conference （VTC Spring）, 2013 IEEE 77th , vol., no., pp.1,5, 2-5 June 2013
[14] Kikuchi, Katsunori; Otsuka, Hiroyuki, "Parameter optimization for adaptive control CRE in HetNet," Personal Indoor and Mobile Radio Communications （PIMRC）, 2013 IEEE 24th International Symposium on , vol., no., pp.3334,3338, 8-11 Sept. 2013
[15] Kikuchi, K.; Otsuka, H., "Proposal of adaptive control CRE in heterogeneous networks," Personal Indoor and Mobile Radio Communications （PIMRC）, 2012 IEEE 23rd International Symposium on , vol., no., pp.910,914, 9-12 Sept. 2012
[16] Peng Tian; Hui Tian; Jianchi Zhu; Lan Chen; Xiaoming She, "An adaptive bias configuration strategy for Range Extension in LTE-Advanced Heterogeneous Networks," Communication Technology and Application （ICCTA 2011）, IET International Conference on , vol., no., pp.336,340, 14-16 Oct. 2011
[17] Xinsheng Zhao; Chao Wang, "An asymmetric cell selection scheme for inter-cell interference coordination in heterogeneous networks," Wireless Communications and Networking Conference （WCNC）, 2013 IEEE , vol., no., pp.1226,1230, 7-10 April 2013
[18] Pedersen, K.I.; Yuanye Wang; Soret, B.; Frederiksen, F., "eICIC Functionality and Performance for LTE HetNet Co-Channel Deployments," Vehicular Technology Conference （VTC Fall）, 2012 IEEE , vol., no., pp.1,5, 3-6 Sept. 2012
[19] Yuanye Wang; Pedersen, K.I., "Performance Analysis of Enhanced Inter-Cell Interference Coordination in LTE-Advanced Heterogeneous Networks," Vehicular Technology Conference （VTC Spring）, 2012 IEEE 75th , vol., no., pp.1,5, 6-9 May 2012
[20] Okino, K.; Nakayama, T.; Yamazaki, C.; Sato, H.; Kusano, Y., "Pico Cell Range Expansion with Interference Mitigation toward LTE-Advanced Heterogeneous Networks," Communications Workshops （ICC）, 2011 IEEE International Conference on , vol., no., pp.1,5, 5-9 June 2011
[21] Guvenc, I.; Moo-Ryong Jeong; Demirdogen, I.; Kecicioglu, B.; Watanabe, F., "Range Expansion and Inter-Cell Interference Coordination （ICIC） for Picocell Networks," Vehicular Technology Conference （VTC Fall）, 2011 IEEE , vol., no., pp.1,6, 5-8 Sept. 2011
[22] Sangmi Moon; Malik, S.; Bora Kim; Hun Choi; Sooman Park; Cheolsung Kim; Intae Hwang, "Cell Range Expansion and Time Partitioning for Enhanced Inter-cell Interference Coordination in Heterogeneous Network," System Sciences （HICSS）, 2014 47th Hawaii International Conference on , vol., no., pp.5109,5113, 6-9 Jan. 2014
[23] Umair, M.Y.; Yang Dongkai; Dengkun Xiao; Fanny, F., "Identification of interferers in Het-Net in LTE-A systems based on FeICIC with cell range expansion," Information and Communication Technology （ICoICT）, 2013 International Conference of , vol., no., pp.198,201, 20-22 March 2013
[24] Mogensen, P.; Wei Na; Kovacs, I.Z.; Frederiksen, F.; Pokhariyal, A.; Pedersen, K.I.; Kolding, T.; Hugl, K.; Kuusela, M., "LTE Capacity Compared to the Shannon Bound," Vehicular Technology Conference, 2007. VTC2007-Spring. IEEE 65th , vol., no., pp.1234,1238, 22-25 April 2007
[25] 3GPP TR 36.814, “Further advancements for E-UTRA physical layer aspects” Version 9.0.0 （March 2010）
[26] 蘇勇達,” LTE 網路之下行鏈路無線電資源管理與睡眠模式之 整合研究”
[27]”LTE-Advanced”[online]Available:http://www.eettaiwan.com/STATIC/PDF/201106/20110624_Agilent_TA01.pdf?SOURCES=DOWNLOAD