在行動網路中之共享保護頻道策略研究

在本論文中，我們提出了一個通用的共享保護頻道策略(generalized shared guard channel scheme, GGC)，此策略使用了一部分的通道作為資料傳輸的專用頻道來保證資料的最小傳輸率。相對於另外兩種保護頻道策略，共享保護頻道策略(shared guard channel scheme, SGC)及專用保護頻道策略(data dedicated guard channel scheme, DGC)，通用的共享保護頻道策略不僅降低了資料遺失率並提高了頻寬利用率。此外，我們考慮了語音與資料封包的緩衝區，來降低語音的阻斷率及資料封包的遺失率。我們利用四個重要的參數來評估這些保護頻道策略的效益，新通話的阻斷率(Pbk,n)、強制中斷遞交通話率(Pft,h)、資料封包遺失率(Ploss,d)及頻寬利用率(u)，而在新通化阻斷率中我們也考慮了新通話的放棄率(Reneging)，同時在強制中斷遞交通話率中我們考慮了遞交通話的丟棄率(Dropping)。透過數值分析及結果顯示通用的共享保護頻道策略不僅維持了良好的服務品質(QoS)且提高了頻寬使用率。

關鍵字

共享保護頻道；頻寬分配；馬可夫鏈

並列摘要

In this thesis, we proposes a generalized shared guard channel scheme (GGC) which can guarantee the data transmission rate at a pre-defined level by reserving a number of channels exclusive for data packet. The key point of GGC is that the shared part of the guard channel not only lower the data packet loss probability but increase the bandwidth utilization compare with other two guard channel strategies, one is the guard channel strategy with the shared guard channel (SGC) and the other is the guard channel strategy without the shared guard channel but with data dedicate guard channel (DGC). Voice and data buffer are adopted to lower the blocking and the loss probability of voice call and data packet respectively. Four parameters, new call blocking probability (Pbk,n), handoff request force terminating probability (Pft,h), data packet loss probability (Ploss,d), and bandwidth utilization (u) are used to evaluate the performance of these schemes, meanwhile the user reneging behavior and dropping behavior is taken into consideration and included in Pbk,n and Pbk,h, respectively. The numerical result shows that the proposed scheme not only guaranteed all the QoS but raised the bandwidth utilization.

並列關鍵字

channel allocation ； Markov chain ； shared guard channel

參考文獻

[1]. A. Xhafa and O. K. Tinguz, “A new queuing scheme for handoff in 3G wireless networks,” in Proc. IEEE VTC Fall ’01, Atlantic City, NJ, pp. 738–742, Oct. 2001.

[2]. W. K. Lai, Y. J. Jin, H-W. Chen, and C-Y. Pan, “Channel assignment for initial and handoff calls to improve the call-completion probability,” IEEE Trans. Veh. Technol., vol. 52, pp. 876–890, July 2003.

[3]. J. Chen and D. Cao, “Performance improvement of prioritized handoff schemes in multi-service mobile cellular systems.” in Proc. IEEE CCECE ’02, Canadian, vol. 3, pp. 1347–1351, 2002.

[4]. T. L. Sheu and Y. J. Wu, “A preemptive channel allocation scheme for multimedia traffic in mobile wireless networks,” Inf. SCI., vol. 176, no. 3,pp. 217–236, Feb. 2006.

[5]. T. L. Sheu, Y. J. Wu, and B. Li, “A generalized channel preemption model for multiclass traffic in mobile wireless networks,” IEEE Trans. Veh. Technol., vol. 56, no. 5, pp. 2723–2732, Sep. 2007.

國際替代計量

在行動網路中之共享保護頻道策略研究

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