本論文探討感知無線網路的頻譜管理問題。在此網路中，來自主要使用者的『多次中斷』將大大地影響次要使用者的通訊效能。每當次要使用者被主要使用者中斷時，次要使用者必須選擇一個適合的通道進行頻譜切換，以便繼續未完成的傳輸。很明顯地，『多次中斷』將造成多次的頻譜切換，並且增加次要使用者連線的傳輸延遲。為了從一個宏觀的角度來分析感知無線網路下『多次中斷』行為對『次要使用者連線』所造成的傳輸延遲，本論文提出一個優先權排隊理論的分析模型替感知無線網路的頻譜使用行為進行建模。藉由此模型，我們分析次要使用者的一個重要服務品質參數：『完整系統時間』。
在此論文中，基於排隊理論分析模型，我們發展具服務品質考量的頻譜管理機制，其中包括 (1) 頻譜選擇機制、(2) 頻譜切換機制、和 (3) 頻譜分享機制的設計與討論。針對這些機制的具體研究成果敘述如下：(1) 針對頻譜選擇問題，我們提出一個具有負載平衡功效的頻譜選擇機制來優化次要使用者的『完整系統時間』；(2) 針對頻譜切換問題，我們量化在多通道下多次頻譜切換對次要使用者所造成的『完整系統時間』增加量；(3) 針對頻譜分享問題，我們提出一個允入控制機制來避免主要使用者被次要使用者干擾並優化次要使用者的『完整系統時間』。我們完整探討這三種頻譜管理機制對次要使用者所造成的傳輸延遲。基於這些分析結果，在不同資料到達率與服務時間分佈下，我們可以設計相對應的頻譜管理機制來增強次要使用者連線的傳輸品質。
總而言之，本論文的主要貢獻是提出一個以排隊理論為基礎的分析模型並用多樣化的角度與觀點來對感知無線網路效能進行分析。本論文所建議之模型可以提供一個很好的感知無線網路效能之分析架構。

In this dissertation, we investigate spectrum management techniques in cognitive radio (CR) networks with quality of service (QoS) provisioning. One fundamental issue in enhancing QoS performance for the secondary users is the multiple interruptions from the primary users during each secondary user's connection. These interruptions from the primary users result in the phenomenon of multiple spectrum handoffs within one secondary user's connection. Thus, a set of target channels for spectrum handoffs are needed to be selected sequentially. In order to characterize the general channel usage behaviors with multiple handoffs from a macroscopic viewpoint, an analytical framework based on the preemptive resumption priority (PRP) M/G/1 queueing theory is introduced. Based on the PRP M/G/1 queueing network model, we can evaluate the effects of multiple handoffs on the overall system time, which is an important QoS performance measure for the secondary connections in CR networks.

The proposed analytical framework can provide important insights into the design of spectrum management techniques in CR networks. In order to demonstrate the effectiveness of this analytical model, we discuss various spectrum management techniques, consisting of spectrum decision, spectrum sharing, and spectrum mobility. For the \emph{spectrum decision} issue, we show how to determine which channels are required to probe and transmit. For the \emph{spectrum mobility} issue, we illustrate how to characterize the effects of multiple handoffs, where the secondary users can have different operating channels before and after spectrum handoff. For the \emph{spectrum sharing} issue, we explore how to determine the optimal admission probability to avoid the interference between primary and secondary users in the presence of false alarm and missed detection. From numerical results, we can develop traffic-adaptive spectrum management policies to enhance the QoS performance of the secondary users in CR networks with various traffic arrival rates and service distributions.

To summarize, the main contribution of this dissertation is to investigate the modeling techniques for CR networks from a macroscopic viewpoint based on the queueing theory. The proposed analytical framework can help analyze the performances of CR networks and provide important insights into the design of various spectrum management techniques with enhanced QoS performances.

1 Introduction 1
1.1 Problems and Solutions . . . . . . . . . . . . . . . . . . . . . . 6
1.1.1 Modeling Techniques for Cognitive Radio Networks . . 6
1.1.2 Load-Balancing Spectrum Decision . . . . . . . . . . . 7
1.1.3 Proactive Spectrum Handoff . . . . . . . . . . . . . . . 8
1.1.4 Optimal Proactive Spectrum Handoff . . . . . . . . . . 9
1.1.5 Reactive Spectrum Handoff . . . . . . . . . . . . . . . 10
1.1.6 Interference-Avoiding Spectrum Sharing . . . . . . . . 10
1.2 Dissertation Outlines . . . . . . . . . . . . . . . . . . . . . . . 11
2 Background and Literature Survey 14
2.1 Modeling Techniques for Cognitive Radio Networks . . . . . . 14
2.2 Load-Balancing Spectrum Decision . . . . . . . . . . . . . . . 16
2.2.1 Probability-based Spectrum Decision . . . . . . . . . . 16
2.2.2 Sensing-based Spectrum Decision . . . . . . . . . . . . 20
2.3 Proactive Spectrum Handoff . . . . . . . . . . . . . . . . . . . 20
2.4 Optimal Proactive Spectrum Handoff . . . . . . . . . . . . . . 24
2.5 Reactive Spectrum Handoff . . . . . . . . . . . . . . . . . . . 25
2.6 Interference-Avoiding Spectrum Sharing . . . . . . . . . . . . 28
2.6.1 Admission Control with Perfect Sensing . . . . . . . . 28
2.6.2 Admission Control without Perfect Sensing . . . . . . . 31
3 Queueing-Theoretical Modeling Techniques for Cognitive Radio Networks 32
3.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.2 Transmission Processes with Multiple Handoffs for the Secondary Users' Connections . . . . . . . . . . . . . . . . . . . . 34
3.3 Queueing Theoretical Framework for Spectrum Management . 37
3.3.1 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . 37
3.3.2 Overview of the PRP M/G/1 Queueing Network Model 37
3.3.3 Modeling of the Connection-based Channel Usage Behaviors . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.3.4 Two Auxiliary Parameters . . . . . . . . 42
3.3.5 Constraint . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4 Load-Balancing Spectrum Decision 46
4.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2.1 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2.2 Spectrum Decision Behavior Model . . . . . . . . . . . 49
4.3 Problem Formulation . . . . . . . . . . . . . . . . . . . . . . . 51
4.3.1 Performance Metric: Overall System Time . . . . . . . 51
4.3.2 Overall System Time Minimization Problem for Probability-based Channel Selection Scheme . . . . . . . . . . . . . 51
4.3.3 Overall System Time Minimization Problem for Sensing-based Channel Selection Scheme . . . . . . . . . . . . . 53
4.3.4 Performance Model . . . . . . . . . . . . . . . . . . . . 54
4.4 Analysis of Overall System Time . . . . . . . . . . . . . . . . 57
4.4.1 Extended Data Delivery Time . . . . . . . . . . . . . . 57
4.4.2 Waiting Time . . . . . . . . . . . . . . . . . . . . . . . 59
4.5 Effects of Sensing Errors . . . . . . . . . . . . . . . . . . . . . 62
4.5.1 False Alarm . . . . . . . . . . . . . . . . . . . . . . . . 63
4.5.2 Missed Detection . . . . . . . . . . . . . . . . . . . . . 64
4.6 Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.6.1 Probability-based Spectrum Decision Scheme . . . . . . 66
4.6.2 Sensing-based Spectrum Decision Scheme . . . . . . . . 70
4.6.3 Comparison between Different Spectrum Decision Schemes 75
5 Proactive Spectrum Handoff 77
5.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.2.1 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . 79
5.2.2 Illustrative Example of Proactive Multiple Handoffs with Multiple Interruptions . . . . . . . . . . . . . . . 80
5.3 Analytical Model . . . . . . . . . . . . . . . . . . . . . . . . . 82
5.4 Analysis of Extended Data Delivery Time . . . . . . . . . . . 84
5.5 Applications to Performance Analysis in IEEE 802.22 . . . . . 92
5.5.1 Derivation of Extended Data Delivery Time . . . . . . 92
5.5.2 An Example for Homogeneous Traffic Loads . . . . . . 93
5.6 Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . 95
5.6.1 Simulation Setup . . . . . . . . . . . . . . . . . . . . . 95
5.6.2 Effects of Various Service Time Distributions for Primary Connections . . . . . . . . . . . . . . . . . . . . . 96
5.6.3 Traffic -adaptive Target Channel Selection Principle . . 98
5.6.4 Performance Comparison between Different Channel Selection Methods . . . . . . . . . . . . . . . . . . . . 103
6 Optimal Proactive Spectrum Handoff 107
6.1 Problem Formulation . . . . . . . . . . . . . . . . . . . . . . . 108
6.2 Cumulative Handoff Delay Analysis . . . . . . . . . . . . . . . 109
6.3 An Optimal Dynamical Programming Algorithm . . . . . . . . 112
6.3.1 State Diagram for Target Channel Sequences . . . . . . 113
6.3.2 Optimal Substructure Property . . . . . . . . . . . . . 115
6.3.3 Dynamic-Programming-Based Target Channel Selection Algorithm . . . . . . . . . . . . . . . . . . . . . . 116
6.4 A Suboptimal Low-Complexity Greedy Algorithm . . . . . . . 117
6.4.1 Greedy Target Channel Selection Strategy . . . . . . . 117
6.4.2 Greedy Target Channel Selection Algorithm . . . . . . 123
6.5 Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . 123
6.5.1 Effects of Traffic Statistics for Arriving Secondary User's Service Time . . . . . . . . . . . . . . . . . . . . . . . 124
6.5.2 Effects of Traffic Statistics of Existing Secondary Users' Connections . . . . . . . . . . . . . . . . . . . . . . . . 125
6.5.3 Effects of Traffic Statistics of Existing Primary Users' Connections . . . . . . . . . . . . . . . . . . . . . . . . 131
7 Reactive Spectrum Handoff 134
7.1 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
7.1.1 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . 136
7.1.2 Illustrative Example of Reactive Multiple Handoffs with
Multiple Interruptions . . . . . . . . . . . . . . . . . . 136
7.2 Analytical Model . . . . . . . . . . . . . . . . . . . . . . . . . 138
7.2.1 Notations . . . . . . . . . . . . . . . . . . . . . . . . . 139
7.3 Analysis of Channel Utilization Factor . . . . . . . . . . . . . 143
7.3.1 Derivations of $\omega_{i,\eta}^{(k)}$ and $\textbf{E}[\Phi_{i,\eta}^{(k)}]$ . . . . . . . . . . . . . . 145
7.3.2 An Example for the Exponentially Distributed Service Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
7.4 Analysis of Extended Data Delivery Time . . . . . . . . . . . 149
7.4.1 Derivations of $\textbf{Pr}\{\textbf{S}^{(\eta)}=\mbox{\boldmath$s$}_N\}$ . . . 149
7.4.2 An Example for the Exponentially Distributed Service Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
7.5 Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . 155
7.5.1 Simulation Setting . . . . . . . . . . . . . . . . . . . . 155
7.5.2 Effects of Various Arrival Rates for the Secondary Users' Connections . . . . . . . . . . . . . . . . . . . . . . . . 155
7.5.3 Effects of Heterogeneous Arrival Rates for the Primary Users' Connections . . . . . . . . . . . . . . . . . . . . 158
7.5.4 Effects of Handoff Processing Time . . . . . . . . . . . 161
7.5.5 Comparison between Proactive and Reactive Spectrum Handoff Scheme . . . . . . . . . . . . . . . . . . . . . . 164
8 Interference-Avoiding Spectrum Sharing 168
8.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
8.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
8.2.1 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . 171
8.2.2 Admission Control Mechanism . . . . . . . . . . . . . . 172
8.3 Problem Formulation and Analytical Model . . . . . . . . . . 172
8.3.1 Problem Formulation . . . . . . . . . . . . . . . . . . . 172
8.3.2 Analytical Model . . . . . . . . . . . . . . . . . . . . . 174
8.4 Analysis of Constraint Functions in the Utilization Maximization Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
8.4.1 Analysis of Actual Service Time of the Primary Connection in the Physical Channel . . . . . . . . . . . . . 175
8.4.2 Analysis of Overall System Time of the Secondary Connections . . . . . . . . . . . . . . . . . . . . . . . . . . 178
8.5 Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . 181
9 Conclusions 185
9.1 Modeling Techniques for Cognitive Radio Networks . . . . . . 186
9.2 Load-Balancing Spectrum Decision . . . . . . . . . . . . . . . 187
9.3 Proactive Spectrum Handoff . . . . . . . . . . . . . . . . . . . 188
9.4 Optimal Proactive Spectrum Handoff . . . . . . . . . . . . . . 188
9.5 Reactive Spectrum Handoff . . . . . . . . . . . . . . . . . . . 189
9.6 Interference-Avoiding Spectrum Sharing . . . . . . . . . . . . 190
9.7 Suggestions for Future Research . . . . . . . . . . . . . . . . . 190
Bibliography 194
Appendices 209

[1] R. W. Brodersen, A. Wolisz, D. Cabric, S. M. Mishra, and D. Willkomm, “CORVUS: A Cognitive Radio Approach for Usage of Virtual Unlicensed Spectrum,” Berkeley Wireless Research Center (BWRC) White paper, 2004.
[2] J. Mitola and G. Q. Maguire, “Cognitive Radio: Making Software Radios More Personal,” IEEE Personal Communications, vol. 6, pp. 13-18, Aug. 1999.
[3] S. Haykin, “Cognitive Radio: Brain-empowered Wireless Communications,” IEEE Journal on Selected Areas in Communications, vol. 23, no. 2, pp. 201-220, Feb. 2005.
[4] R. W. Thomas, L. A. DaSilva, and A. B. MacKenzie, “Cognitive Networks,” IEEE International Symposium on Dynamic Spectrum Access Networks (DYSPAN), Nov. 2005.
[5] I. F. Akyildiz, W.-Y. Lee, M. C. Vuran, and S. Mohanty, “NeXt Generation/Dynamic Spectrum Access/Cognitive Radio Wireless Networks: A Survey,” Computer Networks Journal (Elsevier), vol. 50, pp. 2127-2159, Sep. 2006.
[6] P.-Y. Huang and K.-C. Chen, “A Cognitive CSMA-based Multichannel MAC Protocol for Cognitive Radio Networks,” APSIPA Annual Summit and Conference (ASC), Oct. 2009.
[7] D. Shiung and K.-C. Chen, “On the Optimal Power Allocation of a Cognitive Radio Networks,” IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), Sep. 2009.
[8] S.-Y. Lien, C.-C. Tseng, and K.-C. Chen, “Carrier Sensing based Multiple Access Protocols for Cognitive Radio Networks,” IEEE International Conference on Communications (ICC), May 2008.
9] O. Jo and D.-H. Cho, “Seamless Spectrum Handover Considering Differential Path-loss in Cognitive Radio Systems,” IEEE Communications Letters, vol. 13, no. 3, pp. 190-192, Mar. 2009.
[10] M. D. Silvius, R. Rangnekar, A. B. MacKenzie, and C. W. Bostian, “The Smart Radio Channel Change Protocol: A Primary User Avoidance Technique for Dynamic Spectrum Sharing Cognitive Radios to Facilitate Co-existence in Wireless Communication Networks,” Intenational Conference on Cognitive Radio Oriented Wireless Networks and Communications (CrownCom), Jun. 2009.
[11] A. Sgora and D. D. Vergados, “Handoff Prioritization and Decision Schemes in Wireless Cellular Networks: A Survey,” IEEE Communi-cations Surveys and Tutorials, vol. 11, no. 4, pp. 57-77, 2009.
[12] I. F. Akyildiz, W.-Y. Lee, and K. R. Chowdhury, “CRAHNs: Cognitive Radio Ad Hoc Networks,” Ad Hoc Networks, vol. 7, no. 5, pp. 810-836, 2009
13] I. F. Akyildiz, W.-Y. Lee, M. C. Vuran, and S. Mohanty, “A Survey on Spectrum Management in Cognitive Radio Networks,” IEEE Communications Magazine, vol. 46, no. 4, pp. 40-48, Apr. 2008.
[14] Q. Zhao and A. Swami, “A Decision-theoretic Framework for Opportunistic Spectrum Access,” IEEE Wireless Communications Magazine, vol. 14, no. 4, pp. 14-20, Aug. 2007.
[15] X. Zhu, L. Shen, and T.-S. P. Yum, “Analysis of Cognitive Radio Spectrum Access with Optimal Channel Reservation,” IEEE Communications Letters, vol. 11, no. 4, pp. 304-306, Apr. 2007.
[16] C. Zhang, X. Wang, and J. Li, “Cooperative Cognitive Radio with Priority Queueing Analysis,” IEEE International Conference on Communications (ICC), Jun. 2009.
[17] H. Tran, T. Q. Duong, and H.-J. Zepernick, “Average Waiting Time of Packets with Different Priorities in Cognitive Radio Networks,” IEEE International Symposium on Wireless Pervasive Computing (ISWPC), May 2010.
[18] Y. Zhu, Q. Zhang, Z. Niu, and J. Zhu, “On Optimal QoS-aware Physical Carrier Sensing for IEEE 802.11 Based WLANs: Theoretical Analysis and Protocol Design,” IEEE Transactions on Wireless Communications, vol. 7, no. 4, pp. 1369-1378, April 2008.
[19] A. Banaei and C. N. Georghiades, “Throughput Analysis of a Randomized Sensing Scheme in Cell-based Ad-hoc Cognitive Networks,” IEEE International Conference on Communications (ICC), Jun. 2009.
[20] J. Gambini, O. Simeone, Y. Bar-Ness, U. Spagnolini, and T. Yu, “Packet-wise Vertical Handover for Unlicensed Multi-standard Spectrum Access with Cognitive Radios,” IEEE Transactions on Wireless Communications, vol. 7, no. 12, pp. 5172-5176, Dec. 2008.
[21] J. Gambini, O. Simeone, U. Spagnolini, Y. Bar-Ness, and Y. Kim, “Cognitive Radio with Secondary Packet-By-Packet Vertical Handover,” IEEE International Conference on Communications (ICC), May 2008.
[22] G. Noh, J. Lee, and D. Hong, “Stochastic Multichannel Sensing for Cognitive Radio Systems: Optimal Channel Selection for Sensing with Interference Constraints,” IEEE Vehicular Technology Conference Fall, Sep. 2009.
[23] C.-M. Lee, J.-S. Lin, Y.-P. Hsu, and K.-T. Feng, “Design and Analysis of Optimal Channel-hopping Sequence for Cognitive Radio Networks,” IEEE Wireless Communications and Networking Conference (WCNC), Apr. 2010.
[24] A. T. Chronopoulos, M. R. Musku, S. Penmatsa, and D. C. Popescu, “Spectrum Load Balancing for Medium Access in Cognitive Radio Systems,” IEEE Communications Letters, vol. 12, no. 5, pp. 353-355, May 2008.
[25] I. Malanchini, M. Cesana, and N. Gatti, “On Spectrum Selection Games in Cognitive Radio Networks,” IEEE Global Communications Conference (GLOBECOM), Nov. 2009.
[26] H.-P. Shiang and M. van der Schaar, “Queuing-based Dynamic Channel Selection for Heterogeneous Multimedia Applications Over Cognitive Radio Networks,” IEEE Transactions on Multimedia, vol. 10, no. 5, pp. 896-909, Aug. 2008..
[27] Y. Song, Y. Fang, and Y. Zhang, “Stochastic Channel Selection in Cognitive Radio Networks,” IEEE Global Communications Conference (GLOBECOM), Nov. 2007.
[28] H.-J. Liu, S.-F. Li, Z.-X. Wang, W.-J. Hong, and M. Yi, “Strategy of Dynamic Spectrum Access Based-on Spectrum Pool,” IEEE International Conference on Wireless Communications, Networking and Mobile Computing (WiCOM), Sep. 2008.
[29] A. W. Min and K. G. Shin, “Exploiting Multi-channel Diversity in Spectrum-agile Networks,” IEEE International Conference on Computer Communications (INFOCOM), Apr. 2008.
[30] B. Hamdaoui, “Adaptive Spectrum Assessment for Opportunistic Access in Cognitive Radio Networks,” IEEE Transactions on Wireless Communications, vol. 8, no. 2, pp. 922-930, Feb. 2009.
[31] A. Sabharwal, A. Khoshnevis, and E. Knightly, “Opportunistic Spectral Usage: Bounds and a Multi-band CSMA/CA Protocol,” IEEE/ACM Transactions on Networking, vol. 15, no. 3, pp. 533-545, 2007.
[32] J. Jia, Q. Zhang, and X. S. Shen, “HC-MAC: A Hardware-constrained Cognitive MAC for Efficient Spectrum Management,” IEEE Journal on Selected Areas in Communications, vol. 26, no. 1, pp. 106-117, Jan 2008.
[33] M. Felegyhazi and J.-P. Hubaux, “Game Theory in Wireless Networks: A Tutorial,” EPFL Technical Report: LCA-REPORT-2006-002, 2006.
[34] Q. Zhao, L. Tong, A. Swami, and Y. Chen, “Decentralized Cognitive MAC for Opportunistic Spectrum Access in Ad Hoc Networks: A POMDP Framework,” IEEE Journal on Selected Areas in Communications, vol. 25, no. 3, pp. 589-600, April 2007.
[35] Q. Zhao, S. Geirhofer, L. Tong, and B. M. Sadler, “Opportunistic Spectrum Access via Periodic Channel Sensing,” IEEE Transactions on Signal Processing, vol. 56, no. 2, pp. 785-796, Feb. 2008.
[36] O. Mehanna, A. Sultan, and H. E. Gamal, “Blind Cognitive MAC Protocols,” IEEE International Conference on Communications (ICC), Jun. 2009.
[37] S. Senthuran, A. Anpalagan, and O. Das, “A Predictive Opportunistic Access Scheme for Cognitive Radios,” IEEE Vehicular Technology Conference Fall, Sep. 2009.
[38] L. Yang, L. Cao, and H. Zheng, “Proactive Channel Access in Dynamic Spectrum Networks,” Physical Communication, vol. 1, no. 2, pp. 103-111, 2008.
[39] R.-T. Ma, Y.-P. Hsu, and K.-T. Feng, “A POMDP-based Spectrum Handoff Protocol for Partially Observable Cognitive Radio Networks,” IEEE Wireless Communications and Networking Conference (WCNC), Apr. 2009.
[40] M. Hoyhtya, S. Pollin, and A. Mammela, “Performance Improvement with Predictive Channel Selection for Cognitive Radios,” IEEE International Workshop on Cognitive Radio and Advanced Spectrum Management (CogART), Feb. 2008.
[41] S.-U. Yoon and E. Ekici, “Voluntary Spectrum Handoff: A Novel Approach to Spectrum Management in CRNs,” IEEE International Conference on Communications (ICC), May 2010.
[42] Y. Song and J. Xie, “Common Hopping Based Proactive Spectrum Handoff in Cognitive Radio Ad Hoc Networks,” IEEE Global Communications Conference (GLOBECOM), Dec. 2010.
[43] L.-C. Wang and A. Chen, “On the Performance of Spectrum Handoff for Link Maintenance in Cognitive Radio,” IEEE International Symposium on Wireless Pervasive Computing (ISWPC), May 2008.
[44] B. Wang, Z. Ji, K. J. Ray Liu, and T. C. Clancy, “Primary-prioritized Markov Approach for Dynamic Spectrum Allocation,” IEEE Transactions on Wireless Communications, vol. 8, pp. 1854-1865, Apr. 2009.
[45] I. Suliman and J. Lehtomaki, “Queueing Analysis of Opportunistic Access in Cognitive Radios,” IEEE International Workshop on Cognitive Radio and Advanced Spectrum Management (CogART), May 2009.
[46] H. Li, “Queuing Analysis of Dynamic Spectrum Access Subject to Interruptions from Primary Users,” International Conference on Cognitive Radio Oriented Wireless Networks and Communications (CrownCom), Jun. 2010.
[47] P. Zhu, J. Li, and X. Wang, “A New Channel Parameter for Cognitive Radio,” International Conference on Cognitive Radio Oriented Wireless Networks and Communications (CrownCom), Aug. 2007.
[48] S. Wang and H. Zheng, “A Resource Management Design for Cognitive Radio Ad Hoc Networks,” IEEE Military Communications Conference (MILCOM), Oct. 2009.
[49] F. Borgonovo, M. Cesana, and L. Fratta, “Throughput and Delay Bounds for Cognitive Transmissions,” Advances in Ad Hoc Networking, vol. 265, pp. 179-190, Aug. 2008.
[50] C.-T. Chou, Sai Shankar N, H. Kim, and K. G. Shin, “What and How Much to Gain from Spectral Agility?” IEEE Journal on Selected Areas in Communications, vol. 25, no. 3, pp. 576-588, Apr. 2007.
[51] J. Heo, J. Shin, J. Nam, Y. Lee, J. G. Park, and H.-S. Cho, “Mathematical Analysis of Secondary User Traffic in Cognitive Radio System,” IEEE Vehicular Technology Conference Fall, Sep. 2008.
[52] Y. Zhang, “Spectrum Handoff in Cognitive Radio Networks: Opportunistic and Negotiated Situations,” IEEE International Conference on Communications (ICC), Jun. 2009.
[53] F. Capar, I. Martoyo, T. Weiss, and F. Jondral, “Comparison of Bandwidth Utilization for Controlled and Uncontrolled Channel Assignment in a Spectrum Pooling System,” IEEE Vehicular Technology Conference Spring, May 2002.
[54] B. Ishibashi, N. Bouabdallah, and R. Boutaba, “QoS Performance Analysis of Cognitive Radio-based Virtual Wireless Networks,” IEEE International Conference on Computer Communications (INFOCOM), Apr. 2008.
[55] D. Pacheco-Paramo, V. Pla, and J. Martinez-Bauset, “Optimal Admission Control in Cognitive Radio Networks,” International Conference on Cognitive Radio Oriented Wireless Networks and Communications (CrownCom), Jun. 2009.
[56] W. Ahmed, J. Gao, and M. Faulkner, “Performance Evaluation of a Cognitive Radio Network with Exponential and Truncated Usage Models,” IEEE International Symposium on Wireless Pervasive Computing (ISWPC), Oct. 2009.
[57] M. Huang, R. Yu, and Y. Zhang, “Call Admission Control with Soft-QoS Based Spectrum Handoff in Cognitive Radio Networks,” International Conference on Wireless Communications and Mobile Computing (IWCMC), Jun. 2009.
[58] I. Suliman, J. Lehtomaki, T. Braysy, and K. Umebayashi, “Analysis of Cognitive Radio Networks with Imperfect Sensing,” IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), Sep. 2009.
[59] S. Tang and B. L. Mark, “Performance Analysis of a Wireless Network with Opportunistic Spectrum Sharing,” IEEE Global Communications Conference (GLOBECOM), Nov. 2007.
[60] ||, “Modeling and Analysis of Opportunistic Spectrum Sharing with Unreliable Spectrum Sensing,” IEEE Transactions on Wireless Communications, vol. 8, pp. 1934-1943, Apr. 2009.
[61] ||, “Modeling an Opportunistic Spectrum Sharing System with a Correlated Arrival Process,” IEEE Wireless Communications and Networking Conference (WCNC), Apr. 2008.
[62] ||, “An Analytical Performance Model of Opportunistic Spectrum Access in a Military Environment,” IEEE Wireless Communications and Networking Conference (WCNC), Apr. 2008.
[63] E. W. M. Wong and C. H. Foh, “Analysis of Cognitive Radio Spectrum Access with Finite User Population,” IEEE Communications Letters, vol. 13, no. 5, pp. 294-296, May 2009.
[64] M. M. Rashid, M. J. Hossain, E. Hossain, and V. K. Bhargava, “Opportunistic Spectrum Access in Cognitive Radio Networks: A Queueing Analytic Model and Admission Controller Design,” IEEE Global Communications Conference (GLOBECOM), Nov. 2007.
[65] ||, “Opportunistic Spectrum Scheduling for Multiuser Cognitive Radio: A Queueing Analysis,” IEEE Transactions on Wireless Communications, vol. 8, no. 10, pp. 5259-5269, Oct. 2009.
[66] Y. Zhang, “Dynamic Spectrum Access in Cognitive Radio Wireless Networks,” IEEE International Conference on Communications (ICC), May 2008.
[67] Sai Shankar N, “Squeezing the Most Out of Cognitive Radio: A Joint MAC/PHY Perspective,” IEEE International Conference on Acoustics, Speech and Signal Processing, vol. 4, Apr. 2007.
[68] Sai Shankar N, C.-T. Chou, K. Challapali, and S. Mangold, “Spectrum Agile Radio: Capacity and QoS Implications of Dynamic Spectrum Assignment,” IEEE Global Communications Conference (GLOBECOM), Nov. 2005.
[69] I. Suliman and J. Lehtomaki, “Optimizing Detection Parameters for Time-slotted Cognitive Radios,” IEEE Vehicular Technology Conference Spring, Apr. 2009.
[70] W. Hu, D. Willkomm, G. Vlantis, M. Gerla, and A. Wolisz, “Dynamic Frequency Hopping Communities for Efficient IEEE 802.22 Operation,” IEEE Communications Magazine, vol. 45, no. 5, pp. 80-87, May 2007.
[71] H.-J. Liu, Z.-X. Wang, S.-F. Li, and M. Yi, “Study on the Performance of Spectrum Mobility in Cognitive Wireless Network,” IEEE Singapore International Conference on Communication Systems (ICCS), Jun. 2008.
[72] H. Su and X. Zhang, “Channel-hopping Based Single Transceiver MAC for Cognitive Radio Networks,” IEEE Annual Conference on Information Sciences and Systems (CISS), Mar. 2008.
[73] Y.-C. Liang, Y. Zeng, E. C. Peh, and A. T. Hoang, “Sensing-throughput Tradeoff for Cognitive Radio Networks,” IEEE Transactions on Wireless Communications, vol. 7, no. 4, Apr. 2008.
[74] P. Wang, L. Xiao, S. Zhou, and J. Wang, “Optimization of Detection Time for Channel Efficiency in Cognitive Radio Systems,” IEEE Wireless Communications and Networking Conference (WCNC), Mar. 2007.
[75] W.-Y. Lee and I. F. Akyildiz, “Optimal Spectrum Sensing Framework for Cognitive Radio Networks,” IEEE Transactions on Wireless Communications, vol. 7, no. 10, pp. 3845-3857, Oct. 2008.
[76] C. R. Stevenson, G. Chouinard, Z. Lei, W. Hu, S. J. Shellhammer, and W. Caldwell, “IEEE 802.22: The First Cognitive Radio Wireless Regional Area Network Standard,” IEEE Communications Magazine, vol. 47, no. 1, pp. 130-138, Jan. 2009.
[77] IEEE 802.11, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Speci¯cations, supplement to IEEE 802.11 Standard, Sept. 1999.
[78] L. Kleinrock, Queueing Systems - Volume 2: Computer Applications. John Wiley & Sons Inc., 1975.
[79] L.-C. Wang, C.-W. Wang, and F. Adachi, “Load-balancing Spectrum Decision for Cognitive Radio Networks,” accepted by IEEE Journal on Selected Areas in Communications (JSAC), 2010.
[80] X. Liu and Z. Ding, “ESCAPE: A Channel Evacuation Protocol for Spectrum-agile Networks,” IEEE International Symposium on Dynamic Spectrum Access Networks (DYSPAN), Apr. 2007.
[81] C.-W. Wang, L.-C. Wang, and F. Adachi, “Modeling and Analysis of Multi-user Spectrum Selection Schemes in Cognitive Radio Networks,” IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), Sep. 2009.
[82] X. Li and S. A. Zekavat, “Traffic Pattern Prediction and Performance Investigation for Cognitive Radio Systems,” IEEE Wireless Communications and Networking Conference (WCNC), Mar. 2008.
[83] H. Jiang, L. Lai, R. Fan, and H. V. Poor, “Optimal Selection of Channel Sensing Order in Cognitive Radio,” IEEE Transactions on Wireless Communications, vol. 8, no. 1, pp. 297-307, Jan. 2009.
[84] C.-W.Wang, L.-C.Wang, and F. Adachi, “Performance Gains for Spectrum Utilization in Cognitive Radio Networks with Spectrum Handoff,” International Symposium on Wireless Personal Multimedia Communications (WPMC), Sep. 2009.
[85] C.-W. Wang and L.-C. Wang, “Modeling and Analysis for Proactive-decision Spectrum Handoff in Cognitive Radio Networks,” IEEE International Conference on Communications (ICC), Jun. 2009.
[86] Chee-Hock Ng and Boon-Hee Soong, Queueing Modelling Fundamentals with Applications in Communication Networks, 2nd. John Wiley & Sons Inc., 2008.
[87] Q. Zhao and B. M. Sadler, “A Survey of Dynamic Spectrum Access: Signal Processing, Networking, and Regulatory Policy,” IEEE Signal Processing Magazine, pp. 79-89, May 2007.
[88] N. K. Jaiswal, “Preemptive Resume Priority Queue,” Operations Research, vol. 9, no. 5, pp. 732-742, Sep./Oct. 1961.
[89] Draft Standard for Wireless Regional Area Networks Part 22: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) Speci¯cations, IEEE 802.22 Working Group.
[90] S. Srinivasa and S. A. Jafar, “The Throughput Potential of Cognitive Radio: A Theoretical Perspective,” IEEE Communications Magazine, pp. 73-79, May 2007.
[91] Q. Shi, D. Taubenheim, S. Kyperountas, P. Gorday, and N. Correal, “Link Maintenance Protocol for Cognitive Radio System with OFDM PHY,” IEEE International Symposium on Dynamic Spectrum Access Networks (DYSPAN), Apr. 2007.
[92] C.-W. Wang, L.-C. Wang, and F. Adachi, “Modeling and Analysis for Rective-decision Spectrum Handoff in Cognitive Radio Networks,” IEEE GLOBECOM, Dec. 2010.
[93] D. Willkomm, J. Gross, and A. Wolisz, “Reliable Link Maintenance in Cognitive Radio Systems,” IEEE International Symposium on Dynamic Spectrum Access Networks (DYSPAN), Nov. 2005.
[94] J. Tian and G. Bi, “A New Link Maintenance and Compensation Model for Cognitive UWB Radio Systems,” International Conference on ITS Telecommunications Proceedings, Jun. 2006.
[95] L.-C. Wang and C.-W. Wang, “Spectrum Handoff for Cognitive Radio Networks: Reactive-sensing or Proactive-sensing?” IEEE International Performance Computing and Communications Conference (IPCCC), Dec. 2008.
[96] L.-C. Wang, Y.-C. Lu, C.-W. Wang, and D. S.-L. Wei, “Latency Analysis for Dynamic Spectrum Access in Cognitive Radio: Dedicated or Embedded Control Channel?” IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), Sep. 2007.
[97] R. W. Wolff, “Poisson Arrivals See Time Averages,” Operations Research, vol. 30, no. 2, pp. 223-231, Mar./Apr. 1982.
[98] S. K. Bose, An Introduction to Queueing Systems. Kluwer Academic/Plenum Publishers, New York, 2002.
[99] ETSI, “Universal Mobile Telecommunications System (UMTS); Selection Procedures for The Choice of Radio Transmission Technologies of The UMTS,” Technical Report UMTS 30.03 version 3.2.0, April 1998.
[100] C. R. Stevenson, C. Cordeiro, E. Sofer, and G. Chouinard, “Functional Requirements for The 802.22 WRAN Standard,” IEEE 802.22-05/0007r46, Sep. 2005.
[101] C.-W. Wang, L.-C. Wang, and F. Adachi, “Optimal Admission Control in Cognitive Radio Networks with Sensing Errors,” IEICE Tech. Rep., vol. 109, no. 440, pp. 491-496, Mar. 2010.
[102] L.-C.Wang and C.-W.Wang, “Spectrum Management Techniques with QoS Provisioning in Cognitive Radio Networks,” International Symposium on Wireless and Pervasive Computing (ISWPC), May 2010.
[103] L.-C. Wang, C.-W. Wang, and C.-J. Chang, “Modeling and Analysis for Spectrum Handoffs in Cognitive Radio Networks,” Submitted to IEEE Transactions on Mobile Computing, 2010.
[104] M. S. Jang and D. J. Lee, “Optimum Sensing Time Considering False Alarm in Cognitive Radio Networks,” IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), Sep. 2009.
[105] R. Rao and A. Ephremides, “On the Stability of Interacting Queues in a Multi-access System,” IEEE Transactions on Information Theory, vol. 34, no. 5, pp. 918-930, Sep. 1988.