臺灣博碩士論文加值系統

在行動通訊裡，有效的省電機制將嚴重影響到通訊的生命時間。由於WiMAX屬於終端控制的網路系統，所以基地台透過與用戶端的溝通來訂定各個用戶端在省電過程中的睡眠時間。如此一來可以針對不用服務型態與流量的大小來達到省電的最佳化。在原本的機制中透過指數方式的成長睡眠時間達到有效的省電作用，而在最近的研究中提出了許多最佳化的睡眠時間來達到更有效率的省電效果。但是在這些研究中卻沒有考慮到頻寬的可用度和排程器上的優先等級，如此一來將會使最佳化的睡眠時間得不到任何的效益。因此我們提出了動態喚醒機制 (ATIA)　透過預估頻寬的可以利用度，在頻寬吃緊的狀況下讓基地台動態的選擇用戶端進入額外的睡眠時間以達到更有效率的省電效果。最後我們透過數學分析的過程來驗證方法的效能並且透過實驗的方式驗證我們的方法更可以透過結合其他的省電機制來達到省電的效果。

The efficiency of power saving mechanism on wireless communications will influence the time the mobile station (MSS) can operate. Due to the characteristics of centralized control in WiMAX system, the sleeping period of each subscriber is dominated by a base station (BS) based on their service types, traffic loads, and expected sleeping periods. The power saving mechanism uses an exponential backoff sleeping window manner to determine the
sleeping period of each MS. In recently researches, some of them optimize the sleeping period by estimating the packet inter-arrival time for improving the energy efficient. However, those mechanisms do not reflect the relationship between the traffic load and available bandwidth. That is, according to the available and priorities of connections, the lower priority will can not receive data immediately and waste energy on the waiting time. Thus, in this paper, we propose an adaptive traffic indication algorithm (ATIA) to let MSS do the extend sleep on bandwidth unavailable condition, and illustrate an adaptively adjusting
sleeping window scheme for delay versus energy consumption. Simulation results show that ATIA increase the degree of power saving with comparison to IEEE 802.16e; and further,
it shows ATIA can combine with other power saving mechanism and also get well
performance.

Contents
Abstract vi
List of Tables ix
List of Figures x
1 Introduction 1
1.1 IEEE 802.16e Scheduling services . . . . . . . . . . . . . . . . . . . . . 1
1.2 IEEE 802.16e power saving operation . . . . . . . . . . . . . . . . . . . 2
2 Related work 5
3 Motivation 8
4 System model 10
4.1 Network Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.2 Type I Power Saving Mechanism . . . . . . . . . . . . . . . . . . . . . . 10
4.3 MAC Resource with AMC Scheme . . . . . . . . . . . . . . . . . . . . . 13
5 Adaptive Traffic Indication Algorithm 15
5.1 The Available Bandwidth Allocation . . . . . . . . . . . . . . . . . . . . 15
5.2 The Selection Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.3 Example of ATIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6 Performance Analysis 19
6.1 Analysis Result . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7 Simulation 25
8 Conclusion and FutureWork 27

List of Tables
7.1 Parameters Used in our Simulation. . . . . . . . . . . . . . . . . . . . . 26

List of Figures
1.1 The power saving operation of PSC I. . . . . . . . . . . . . . . . . . . . 3
1.2 The power saving operation of PSC II. . . . . . . . . . . . . . . . . . . . 4
2.1 Markov Chain Model for Power saving Classes Type I [3]. . . . . . . . . 6
2.2 Markov Chain Model for Power saving Classes Type II [3]. . . . . . . . . 6
2.3 MAC state diagram [6]. . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4 The operation of hybrid power saving mechanism [7]. . . . . . . . . . . . 7
3.1 The operation of hybrid power saving mechanism. . . . . . . . . . . . . . 9
4.1 The type I power saving operation in IEEE 802.16e standard. . . . . . . . 11
4.2 The state transition diagram of PSM. . . . . . . . . . . . . . . . . . . . . 12
5.1 The state transition diagram between SN and SE. . . . . . . . . . . . . . 17
5.2 An example of ATIA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.1 Energy consumption among different traffic ratio. . . . . . . . . . . . . . 22
6.2 The energy consumption among different Te. . . . . . . . . . . . . . . . 23
6.3 The energy consumption among different Tmin. . . . . . . . . . . . . . . 24
7.1 Simulation of energy consumption among different bandwidth condition. 26

[1] IEEE 802.16 Working Group, “IEEE Standard for Local and Metropolitan Area
Networks–Part 16: Air Interface for Fixed Broadband Wireless Access Systems,”
IEEE Std. 802.16-2004, October 2004.
[2] IEEE Std 802.16e-2005, “Part 16: Air Interface for Fixed and Mobile Broadband
Wireless Access Systems,” February 2006.
[3] L. Kong and D. H.K. Tsang, “Performance Study of Power Saving Classes of Type
I and II in IEEE 802.16e,” in Proc. IEEE Local Computer Networks, pp.20–27,
Tampa, Florida, November 2006.
[4] H. Kwanghun and C. Sunghyun, “Performance Analysis of Sleep Mode Operation
in IEEE 802.16e Mobile BroadbandWireless Access Systems,” in Proc. IEEE VTCSpring
2006, pp.1141–1145, Melbourne, Australia, May 2006.
[5] Z. Yan, “Performance Modeling of Energy Management Mechanism in IEEE
802.16e MobileWiMAX,” in Proc. IEEE WCNC 2007, pp.3205–3209, Hong Kong,
March 2007.
[6] N.-H. Lee and S. Bahk, “MAC Sleep Mode Control Considering Downlink Traffic
Pattern and Mobility,” in Proc. IEEE VTC-Spring 2005, pp.2076–2080, Stockholm,
Sweden, June 2005.
[7] H.-H. Choi, J.-R. Lee, and D.-H. Cho, “Hybrid Power Saving Mechanism for VoIP
Services with Silence Suppression in IEEE 802.16e Systems,” IEEE Commun. Letters,
pp.455–457, May 2007.
[8] M.G. Kim, J.Y. Choi, and M. Kang, “Adaptive Power Saving Mechanism Considering
the Request Period of Each Initiation of Awakening in the IEEE 802.16e System,”
IEEE Commun. Letters, vol. 12, no. 2, February 2008.
[9] W. Stallings, High-Speed Networks and Internets: Performance and Quality of Service,
Prentice Hall, 2002.
[10] L. Georgiadis, R. Guerin, and A. Parekh, “Optimal Multiplexing on a Single Link:
Delay and Buffer Requirements,” IEEE Trans. Information Theory, vol. 43, no. 5,
pp.1518–1535, September 1997.
[11] S.H. ALi, K. Lee, and V.C.M. Leung, “Dynamic Resource Allocation in OFDMA wireless Metropolitan Area Networks,” IEEE Wireless Commun. Mag., vol. 14, no.
1, pp.6–13, February 2007.