臺灣博碩士論文加值系統

近年來拜行動通訊科技快速發展所賜，行動通訊服務需求量持續升高，各項新穎之行動通訊加值服務與多元化行動通訊功能不斷推廣。有鑑於行動通訊網路系統均具備多種網路資源管理之高度複雜性，為求整體通訊效能之確保以及構建與營運成本之控制，本論文的研究內容包括：(1) 整合式網路規劃 (integrated network planning)、(2) 網路效能優化 (performance assurance & optimization) 以及 (3) 即期性網路效能回復 (network servicing) 三大模組。
整合式網路規劃模組針對行動通訊網路系統，透過數學最佳化方法之推演以決定所採用之無線通訊基地台配置、方向性天線規劃、功率控制、頻道配置與傳輸設備容量配置，其最終目的在滿足網路效能條件限制下，儘量降低系統之構建與營運成本。網路效能優化模組則植基於網路規劃架構、訊務量分佈以及訊務模型特性之考量，最佳化調整網路系統參數與管制系統資源，進而優化系統效能標的。至於即期性網路效能回復模組則是當網路效能劣化時，必須即期考慮當時之基地台資源配置、網路負載以及訊務分佈，藉由路由重設 (rerouting) 及容量擴增 (capacity augmentation) 等策略儘快使劣化之系統效能回復正常。
本論文針對頻道再利用所造成之干擾現象，考量廣用型無線電波傳播特性，發展出一般性頻道干擾數學模型以及彈性頻道分配演算法，在整體考量同頻干擾與鄰頻干擾以確保通訊品質之前提下，達到效能最佳化之目的。並且由於無線通訊仰賴之無線電波傳輸媒介易招受天然氣候與人為環境之干擾，通訊服務之可靠度 (reliability) 乃成為一項無線通訊規劃與管理之重要議題，本論文亦探討多重連線 (multiple-connectivity) 在無線通訊網路整體規劃與資源分配之影響，發展出循序尋徑 (sequential routing) 演算法與相關數學模型。本論文植基於此兩項數學演算法為核心發展出上述三模組之最佳化模型，形成完整之無線通訊網路資源分配與管理研究。
由於此類問題的本質均具高度複雜性與困難度，為求最佳化決策之時效與品質，特採用數學模式化 (mathematical formulation) 以及數學規劃法 (mathematical programming) 等最佳化技巧為基礎方略，特別是利用拉格蘭日鬆弛法 (Lagrangean Relaxation) 在解決複雜度高之最佳化數學問題上有非常好之表現，此種數學最佳化模式所展現在各模組之實驗結果顯示相較於一般性之方法迭可獲致數倍之效能或成本改良。

With the rapid growth of advanced wireless technologies, the mobile applications are considered necessary by most people. Being able to well designed and efficiently manage wireless communication networks is a critical issue for operators to optimize their system revenue. In this dissertation, we identify several research topics and critical issues about wireless communication networks, which consist of three modules: (1) integrated network planning, (2) performance assurance and optimization and (3) network-servicing modules.
In the integrated network planning module, we deal with reliable network design problem by considering base station allocation, sectorization, power control, channel assignment, homing policy, multiple-connectivity and capacity management problems altogether. The objective is to minimize total network installation cost subject to several quality of service, grade of service, configuration and performance constraints. In the performance assurance and optimization module, we try to optimize system performance by considering the existing system architecture, traffic distribution, traffic load and quality of service requirements. The objective is to minimize the total loss revenue in the system by adopting admission control, channel assignment and homing policies. In the network-servicing module, due to traffic growth and traffic distribution change, system becomes infeasible and inefficient. To adopt channel re-assignment, power control, re-homing and channel augmentation policies to facilitate the network is the major objective of this module.
The emphases of this dissertation are to develop a generic channel interference model and a sequential routing model for channelized wireless communication networks. To ensure communication quality of service, we propose a generic channel interference model for the flexible channel assignment problem considering co-channel, adjacent channel and near channel interferences. Owing to the unstable properties of wireless air interface, we apply a sequential routing algorithm to guide realtime homing sequence under reliable multiple-connectivity wireless networks. Furthermore, these two algorithms can help to develop the integrated network planning, performance optimization and network servicing modules.
To fulfill the timing and the quality of the optimal decisions, we construct several mathematical formulations that can further enhance performance and reduce cost than general methods. Lagrangean relaxation method, having been proved good in solving the complicated mathematical mode, is chosen to solve our problems.

中文摘要 III
ABSTRACT V
Table of Contents VII
List of Figures X
List of Tables XI
1. Introduction 1
1.1 Overview 1
1.2 Research Scope 3
1.3 Dissertation Organization 7
2. Research Background 9
2.1 Frequency Resource Technologies 9
2.1.1 Radio Propagation Models 9
2.1.1.1 The Empirical Models 10
2.1.1.2 The Physical Models 12
2.1.1.3 The Proposed Extended COST231 Model 14
2.1.2 Frequency Spacing 16
2.2 Wireless Resource Allocation and Management 19
2.2.1 Smart Antenna and Sectorization 19
2.2.2 Channel Assignment 21
2.2.3 Power Control 23
2.2.4 Network Planning 24
2.3 Mathematical Models 26
2.3.1 Communication QoS Models 26
2.3.1.1 BS-based Interference Model 27
2.3.1.2 Over-estimation Interference Model 28
2.3.1.3 MT-based Interference Model 28
2.3.2 Communication GoS Models 29
2.3.2.1 Call-Blocking Probability Constraint 29
2.3.2.2 Call-Dropping Rate Constraint 30
3. Flexible Channel Assignment Problem 31
3.1 Introduction 31
3.2 Problem Description 33
3.3 Solution Procedure 35
3.3.1 Lagrangean Relaxation Method 36
3.3.2 The Dual Problem and the Subgradient Method 37
3.3.3 Getting Primal Feasible Solutions 38
3.4 Computational Experiments 40
3.4.1 Benchmark Problems 40
3.4.2 Primal Heuristics 42
3.4.3 Experiment Environments 44
3.4.4 Experiment Results 45
3.5 Concluding Remarks 47
4. Sequential Homing Problem 49
4.1 Introduction 50
4.2 Sequential Routing Problem 51
4.2.1 Problem Description 51
4.2.2 Program Formulation 53
4.3 Solution Procedure 54
4.3.1 Lagrangean Relaxation Method 55
4.3.2 The Dual Problem and the Subgradient Method 58
4.3.3 Getting Primal Feasible Solutions 59
4.4 Computational Experiments 60
4.4.1 The Proposed Primal Heuristics 60
4.4.2 The DR5 Algorithm 61
4.4.3 Lagrange Relaxation Based Algorithm 62
4.4.4 Experiment Scenarios 62
4.4.5 Experiment Results 63
4.4.6 Computational Time 66
4.5 Concluding Remarks 66
5. Network Planning Module 69
5.1 Introduction 70
5.2 Reliable Wireless Network Design Problem 71
5.2.1 Problem Description 71
5.2.2 Problem Formulation 74
5.3 Solution Procedure 76
5.3.1 Lagrangean Relaxation Method 77
5.3.2 The Dual Problem and the Subgradient Method 86
5.4 Getting Primal Feasible Solutions 86
5.4.1 Heuristic A: BS Configuration Subproblem 87
5.4.2 Heuristic B: Sequential Homing Subproblem 89
5.4.3 Heuristic C: Channel Assignment Subproblem 89
5.5 Computational Experiments 90
5.5.1 Primal Algorithm 91
5.5.2 Lagrangean Relaxation Based Algorithm 92
5.5.3 Experiment Environments 93
5.5.3.1 Assumptions 93
5.5.3.2 Parameters 94
5.5.3.3 Scenarios 95
5.5.4 Experiment Results 95
5.5.5 Computational Complexity 95
5.6 Concluding Remarks 97
6. Performance Assurance and Optimization Module 101
6.1 Introduction 102
6.2 Performance Optimization Problem 104
6.2.1 Problem Description 104
6.2.2 Problem Formulation 106
6.3 Solution Procedure 108
6.3.1 Lagrangean Relaxation Method 109
6.3.2 The Dual Problem and the Subgradient Method 110
6.3.3 Getting Primal Feasible Solutions 111
6.4 Computational Experiments 113
6.4.1 Primal Heuristic 113
6.4.2 Experiment Results 114
6.5 Concluding Remarks 115
7. Network Servicing Module 117
7.1 Introduction 118
7.2 Resource Rearrangement and Augmentation Problem 119
7.2.1 Problem Description 119
7.2.2 Problem Formulation 121
7.3 Solution Procedure 123
7.3.1 Lagrangean Relaxation Method 123
7.3.2 The Dual Problem and the Subgradient Method 127
7.3.3 Getting Primal Feasible Solutions 128
7.4 Computational Experiments 130
7.4.1 Primal Heuristic 130
7.4.2 Lagrangean Relaxation Based Algorithm 130
7.4.3 Experiment Results 132
7.5 Concluding Remarks 133
8. Conclusion and Future Researches 135
8.1 Summary 135
8.2 Future Research 138
References 139
Appendix A Acronyms and Notation 150
A.1 Acronyms 150
A.2 Notation 151

[1] R.K. Ahuja, T.L. Magnanti and J.B. Orlin, Network Flows: Theory, Algorithms, and Applications, Prentice Hall, 1993.
[2] L. Anderson, “A simulation study of sonle dynamic channel assignment algorithms in high capacity mobile telecommunications system,” IEEE Transactions on Vehicular Technology, vol. 22, pp. 210, 1973.
[3] M.S. Bazaraa, H.D. Sherali and C.M. Shetty, Nonlinear Programming: Theory and Algorithms, 2nd Ed., John Wiley & Sons, 1993.
[4] D. Beckmann and U. Killat, “A new strategy for the application of genetic algorithms to the channel-assignment problem,” IEEE Transactions on Vehicular Technology, vol. 48, no. 4, pp. 1261-1269, 1999.
[5] D.P. Bertsekas, Constrained Optimization and Lagrange Multiplier Methods, Academic Press, 1982.
[6] D.P. Bertsekas and R. Gallager, Data Networks, 2nd Ed., Prentice-Hall, 1992.
[7] R. Bose, “Computational complexity of optimal determination of cell sites and base station locations,” Proc. IEEE International Conference on Personal Wireless Communication, pp. 462-466, 1999.
[8] A.O. Boukalov and S-G. Häggman, “System aspects of smart-antenna technology in cellular wireless communications — an overview,” IEEE Transactions on Microwave Theory and Techniques, vol. 48, no. 6, pp. 919-929, 2000.
[9] G.K. Chan, “Effects of sectorization on the spectrum efficiency of cellular radio systems,” IEEE Transactions on Vehicular Technology, vol. 41, no. 3, pp. 217-225, August 1992.
[10] M. Chiang, “Convex optimization of antenna power control for wireless cellular systems,” Proc. IEEE Conference on Antennas and Propagation for Wireless Communications, pp. 179 —182, 2000.
[11] I. Cidon, R. Rom and Y. Shavitt, “Multi-path routing combined with resource reservation,” Proc. IEEE INFOCOM, vol. 1, pp. 92-100, 1997.
[12] COST 231 Final report, Digital Mobile Radio COST 231 View on the Evolution Towards 3rd Generation Systems, Commission of the European Communities and COST Telecommunications, Brussels, 1999.
[13] J. Deygout, “Multiple knife edge diffraction of microwaves,” IEEE Transactions on Antennas and Propagation, vol. 14, no. 4, pp. 480-489, 1966.
[14] H. Everett III, “Generalized Lagrange multiplier method for solving problems of optimum allocation of resources,” Operations Research, vol. 11, pp. 399-417, 1963.
[15] M.L. Fisher, “The Lagrangian relaxation method for solving integer programming problems,” Management Science, vol. 27, no. 1, pp. 1-18, 1981.
[16] M.L. Fisher, “An applications oriented guide to Lagrangian relaxation,” Interfaces, vol. 15, no. 2, pp. 10-21, 1985.
[17] B.H. Fleury and P.E. Leuthold, “Radio wave propagation in mobile communications: an overview of European research,” IEEE Communications Magazine, pp. 70-81, February 1996.
[18] G.J. Foschini and Z. Miljanic, “A simple distributed autonomous power control algorithm and its convergence,” IEEE Transactions on Vehicular Technology, vol. 42, no. 4, pp. 641-646, 1993.
[19] A. Gamst, “Some lower bounds for a class of frequency assignment problem,” IEEE Transactions on Vehicular Technology, vol. 35, pp. 8-14, Feb. 1986.
[20] V.K. Garg and R.V. Yellapantula, “A tool to calculate Erlang capacity of a BTS supporting 3G UMTS system,” Proc. ICPWC, pp. 173-177, 2000.
[21] B. Gavish, “On obtaining the ‘best’ multipliers for a Lagrangean relaxation for integer programming,” Comput. & Operations Research, vol. 5, pp. 55-71, 1978.
[22] B. Gavish, “Augmented Lagrangian based algorithms for centralized network design,” IEEE Transactions on Communications, vol. 33, pp. 1247-1257, 1985.
[23] B. Gavish and S. Sridhar, “Economic aspects of configuring cellular networks,” Wireless Networks, vol. 1, no. 1, pp. 115-128, February 1995.
[24] A.M. Geoffrion, “Lagrangean relaxation and its use in integer programming,” Mathematical Programming Study, vol. 2, pp. 82-114, 1974.
[25] J.L. Goffin, “On convergence rates of subgradient optimization methods,” Mathematical Programming, vol. 13, pp. 329-347, 1977.
[26] S. Golestaneh, H.M. Hafez and S.A. Mahmoud, “The effect of adjacent channel interference on the capacity of FDMA cellular systems,” IEEE Transactions on Vehicular Technology, vol. 43, no. 4, 1994.
[27] W.K. Hale, “Frequency assignment: theory and applications,” Proc. IEEE, vol. 38, pp. 1497-1514, 1980.
[28] Q. Hao, B-H. Soong, E Gunawan, J-T. Ong, C-B Soh and Z. Li, “A low-cost cellular mobile communication system: a hierarchical optimization network resource planning approach,” IEEE Journal on Selected Areas in Communications, vol. 15, no. 7, pp. 1315-1326, 1997.
[29] M. Hata, “Empirical formula for propagation loss in land mobile radio services,” IEEE Transactions on Vehicular Technology, vol. 29, pp. 317-325, 1980.
[30] M. Held, P. Wolfe and H.D. Crowder, “Validation of subgradient optimization,” Mathematical Programming, vol. 6, pp. 62-88, 1974.
[31] X. Huang, U. Behr and W. Wiesbeck, “Automatic cell planning for a low-cost and spectrum efficient wireless network,” Proc. IEEE Global Telecommunications Conference, vol. 1, pp. 276-282, 2000.
[32] F. Ikegami, T. Takeuchi and S. Yoshida, “Theoretical prediction of mean field strength for urban mobile radio,” IEEE Transactions on Antennas and Propagation, vol. 39, no. 3, pp. 299-302, 1991.
[33] K. Ivanov, C. Lüders and U. Rehfueß, “Estimating and comparing the upper bounds on the capacity gain from different smart antenna concepts in GSM mobile radio networks,” Proc. IEEE Vehicular Technology Conference, pp. 499-504, 1998.
[34] H. Jiang and S. S. Rappaport, “CBWL: a new channel assignment and sharing method for cellular communication systems,” IEEE Transactions on Vehicular Technology, vol. 43, pp. 313-321, 1994.
[35] M-H. Jin, H-K. Wu, J-T. Horng and C-H. Tsai, “An evolutionary approach to fixed channel assignment problems with limited bandwidth constraint,” Proc. IEEE International Conference on Communications, vol. 7, pp. 2100-2104, 2001.
[36] B.C. Jones and D.J. Skellern, “Derivation of cochannel and adjacent channel reuse ratio distributions in DCA cellular systems,” IEEE Transactions on Vehicular Technology, vol. 49, no. 1, pp. 50-62, 2000.
[37] T.J. Kahwa and N. Georganas, “A hybrid channel assignment scheme in large scale cellular-structured mobile communication systems,” IEEE Transactions on Communications, vol. 26, pp. 432-438, 1978.
[38] I. Katzela and M. Naghshineh, “Channel assignment schemes for cellular mobile telecommunication systems: a comprehensive survey,” IEEE Personal Communications, vol. 3, no. 3, pp. 10-31, June 1996.
[39] J.S. Kim, S.H. Park, P.W. Dowd and N.M. Nasrabadi, “Cellular radio channel assignment using a modified Hopfield network,” IEEE Transactions on Vehicular Technology, vol. 46, pp. 957-967, 1997.
[40] S. Kim and S-L. Kim, “A two-phase algorithm for frequency assignment in cellular mobile systems,” IEEE Transactions on Vehicular Technology, vol. 43, pp. 542-548, 1994.
[41] S-L Kim, Y. Han and S-H. Hwang, “A traffic and interference adaptive DCA algorithm with rearrangement in micro-cellular systems,” Proc. IEEE 45th Vehicular Technology Conference, Vol. 1, pp. 130-134, 1995.
[42] T-M. Ko, “A frequency selective insertion strategy for fixed channel assignment,” Proc. IEEE International Symposium of Personal, Indoor and Mobile Radio Communications, pp. 311-314, 1994.
[43] K.R. Krishnan, “Dynamic selection of number of routes for sequential routing,” Proc. IEEE Global Telecommunications Conference, vol. 2, pp. 810-813, 1992.
[44] G.V. Kumar and A.P. Shivaprasad, “Channel swapping based dynamic channel allocation,” Proc. IEEE International Conference on Universal Personal Communications, vol. 1, pp. 163 -167, 1998.
[45] T. Kürner, D.J. Cichon and W. Wiesbeck, “Concepts and results for 3D digital terrain-based wave propagation models: an overview,” IEEE Journal on Selected Areas in Communications, vol. 11, no. 7, pp. 1002-1012, 1993.
[46] T. Kürner, D.J. Cichon and W. Wiesbeck, “The influence of land usage on UHF wave propagation in the receiver near range,” IEEE Transactions on Vehicular Technology, vol. 46, no. 3, pp. 739-747, 1997.
[47] M. Lebherz, W. Wiesbeck and W. Krank, “A versatile wave propagation model for the VHF/UHF range considering three-dimensional terrain,” IEEE Transactions on Antennas and Propagation, vol. 40, no. 10, pp. 1121-1131, 1992.
[48] C-H. Lin and F.Y-S. Lin, “Channel augmentation algorithm for wireless networks considering generic sectorization and channel interference,” Proc. The 3rd IEEE International Conference in Mobile and Wireless Communication Networks, Brazil, 2001.
[49] C-H. Lin and F.Y-S. Lin, “Channel reassignment, augmentation and power control algorithm for wireless communication networks considering generic sectorization and channel interference,” Proc. IEEE Emerging Technologies Symposium on Broadband Communications for the Internet Era, Texas, 2001.
[50] C-H. Lin and F.Y-S. Lin, “Admission control algorithm for wireless communication networks considering adjustable channel separation,” Proc. IEEE Canadian Conference of Electrical and Computer Engineering, Winnipeg, Canada, May 2002.
[51] C-H. Lin and F.Y-S. Lin, “Resource and performance management in wireless communication networks,” Proc. IEEE Symposium on Computers and Communications, Italy, July 2002.
[52] C-H. Lin and F.Y-S. Lin, “A sequential routing algorithm in virtual circuit networks considering realtime admission control,” Proc. International Computer Symposium, Taiwan, December 2002.
[53] C-H. Lin and F.Y-S. Lin, “Reliable wireless communication network design considering customized multiple-connectivity,” Proc. International Computer Symposium, Taiwan, December 2002.
[54] C-H. Lin, F.Y-S. Lin and Jia-An Lin, “Resource management and performance optimization of wireless communication networks considering the effect of obstacles and configurable sectorization,” Proc. International Computer Symposium, Taiwan, December 2002.
[55] F.Y-S. Lin, “Link set sizing for networks supporting SMDS,” IEEE/ACM Transactions on Networking, vol. 1, no. 6, pp. 729-739, 1993.
[56] F.Y-S. Lin, “Quasi-static channel assignment algorithms for wireless communications networks,” Proc. ICOIN’98, Japan, January 1998.
[57] F.Y-S. Lin and C.T. Chen, "Admission control and routing algorithms for networks supporting the permanent virtual connection (PVC) service," Proc. ISCOM'97, 1997.
[58] F.Y-S. Lin and J.R. Yee, “A distributed routing algorithm for virtual circuit networks,” Proc. IEEE INFOCOM, Ottawa, Canada, April 1989.
[59] F.Y-S. Lin and J.R. Yee, “Three algorithms for routing and flow control in virtual circuit networks,” Proc. IEEE GLOBECOM, San Diego, December 1990.
[60] F.Y-S. Lin and J.R. Yee, “A new multiplier adjustment procedure for the distributed computation of routing assignments in virtual circuit data networks,” ORSA Journal on Computing, vol. 4, no. 3, pp. 250-266, 1992.
[61] F.Y-S. Lin and J.R. Yee, “A real-time routing and admission control algorithm for ATM networks,” Proc. IEEE INFOCOM, San Francisco, April 1993.
[62] D.G. Luenberger, Linear and Nonlinear Programming, 2nd Ed., Addison-Wesley, 1984.
[63] P. Malm and T. Maseng, “Adjacent channel separation in mobile cellular systems,” Proc. IEEE Vehicular Technology Conference, vol. 2, pp. 642—646, 1997.
[64] S. Marano and C. Mastroianni, “A hierarchical network scheme for multi-layered cellular systems,” Proc. IEEE Vehicular Technology Conference, May 1997.
[65] R.J. McEliece and K.N. Sivarajan, “Performance limits for channelized cellular telephone systems,” IEEE Transactions on Information Theory, vol. 40, pp. 21-34, 1994.
[66] M. Meo and M.A. Marsan, “Approximate analytical models for dual-band GSM networks design and planning,” Proc. IEEE INFOCOM, pp. 1263-1272, 2000.
[67] M. Meo and E. Viterbo, “Performance of wideband CDMA systems supporting multimedia traffic,” IEEE Communications Letters, vol. 5, no. 6, pp. 251-253, 2001.
[68] Y-S. Myung, H-J. Kim and D-W. Tcha, “Design of communication networks with survivability constraints,” Management Science, vol. 45, no. 2, pp. 238-252, 1999.
[69] M. Naghshineh and I. Katzela, “Channel assignment schemes for cellular mobile telecommunications systems: A comprehensive survey,” IEEE Personal Communications, vol. 3, pp. 10-31, June 1996.
[70] R.W. Nettleton and G.R. Schloemer, “A high-capacity assignment method for cellular mobile telephone systems,” Proc. IEEE Vehicular Technology Conference, San Francisco, 1989.
[71] C.Y. Ngo and V.O.K. Li, “Fixed channel assignment in cellular radio networks using a modified genetic algorithm,” IEEE Transactions on Vehicular Technology, vol. 47, pp. 163-172, 1998.
[72] K. Okada and F. Kubota, “A performance study on dynamic channel assignment strategies in micro cellular systems,” Proc. IEICE Conference, 1991.
[73] S. Ramanathan, “A unified framework and algorithm for channel assignment in wireless networks,” Wireless Networks, vol. 5, pp. 81-94, 1999.
[74] R.L. Rardin, Optimization in Operations Research, Prentice-Hall, 1998.
[75] R. Rhenshmidth and M. Tangemann, “Performance of sectorized spatial multiplex systems,” Proc. IEEE Vehicular Technology Conference, pp. 426-430, 1996.
[76] D. Saha, A. Mukherjee and S. K. Dutta, “Design of computer communication networks under link reliability constraints,” Proc. Computer, Communication, Control and Power Engineering, TENCON '93, vol. 1, pp. 188-191, 1993.
[77] S.R. Saunders, Antennas and Propagation for Wireless Communication systems, John Wiley & Sons, 1999.
[78] S. Sawant and D.K. Anvekar, “Capacity improvement in CDMA and FDMA cellular mobile communication systems using adaptive antennas,” Proc. IEEE ICPWC’99, pp. 75-77, 1999.
[79] D-W. Shin, E.K.P. Chong and H.J. Siegel, “A multi-constraint QoS routing scheme using the depth-first search method with limited crankbacks,” Proc. IEEE Workshop on High Performance Switching and Routing, pp. 385-389, 2001.
[80] K.G. Shin, C-C. Chou and S-K. Kweon, “Distributed route selection for establishing real-time channels,” IEEE Transactions on Parallel and Distributed Systems, vol. 11, no. 3, pp. 318-335, March 2000.
[81] N.R. Sollenberger, N. Seshadri and R. Cox, “The evolution of IS-136 TDMA for third-generation wireless services,” IEEE Personal Communications, June 1999.
[82] C.W. Sung and W.S. Wong, “Sequential packing algorithm for channel assignment under cochannel and adjacent-channel interference constraint,” IEEE Transactions on Vehicular Technology, vol. 46, pp. 676-686, 1997.
[83] J. Tajima and K. Imamura, “A strategy for flexible channel assignment in mobile communication systems,” IEEE Transactions on Vehicular Technology, vol. 37, no. 2, pp. 92-103, 1988.
[84] A. Thavarajah and W.H. Lam, “A heuristic algorithm for channel assignment in cellular mobile systems,” Proc. IEEE Vehicular Technology Conference, vol. 3, pp. 1690-1694, 1998.
[85] M. Tu, “Estimation of point-to-point traffic demand in the public switched telephone network,” IEEE Transactions on Communications, vol. 42, no. 2, pp. 840-845, 1994.
[86] L.F. Turner and A.I. Giortzis, “A mathematical programming approach to the channel assignment problem in radio networks,” Proc. IEEE Vehicular Technology Conference, Atlanta, May 1996.
[87] M.A. Venkataramanan, J.J. Dinkel and J. Mote, “A surrogate and Lagrangian approach to constrainted network problems,” Annals of Operations Research, vol. 20, pp. 283-302, 1989.
[88] J. Vucetic, “A hardware implementation of channel allocation algorithm based on a space-bandwidth model of a cellular network,” IEEE Transactions on Vehicular Technology, vol. 42, pp. 444-455, 1993.
[89] J. Walfisch and H.L. Bertoni, “A theoretical model of UHF Propagation in urban environments,” IEEE Transactions on Antennas and Propagation, vol. 36, no. 12, pp. 1788-1796, 1988.
[90] W. Wang and C.K. Rushforth, “An adaptive local-search algorithm for the channel-assignment problem,” IEEE Transactions on Vehicular Technology, vol. 45, pp. 459-466, 1996.
[91] W. Yue, “A graphical method for cellular/PCS system design tradeoffs,” IEEE Communication Magazine, pp. 146-152, Sep. 1996.
[92] W. Yue, “Analytical methods to calculate the performance of a cellular mobile radio communication system with hybrid channel assignment,” IEEE Transactions on Vehicular Technology, vol. 40, pp. 453-460, 1991.
[93] J. Zander, “Performance of optimum transmitter power control in cellular radio systems,” IEEE Transactions on Vehicular Technology, vol. 41, no. 1, pp. 57-62, 1992.
[94] M. Zhang and T-S. P. Yum, “Comparisons of channel-assignment strategies in cellular mobile telephone systems,” IEEE Transactions on Vehicular Technology, vol. 38, pp. 211-215, 1989.
[95] M. Zhang and T-S. P. Yum, “The non-uniform compact pattern allocation algorithm for cellular mobile systems,” IEEE Transactions on Vehicular Technology, vol. 40, pp. 387-391, 1991.