林宗男臺灣大學：電信工程學研究所林柏江Lin, Po-ChiangPo-ChiangLin2007-11-272018-07-052007-11-272018-07-052005http://ntur.lib.ntu.edu.tw//handle/246246/58656傳統的交遞排序方法使用其所接收到的訊號強度作為訂定優先順序的基準。然而，接收到的訊號強度並不是用來表示使用者所感受到服務品質的唯一指標。有許多其他因素，如雜訊、干擾、封包長度、調變 / 編碼方式等，都會影響到服務品質。在這篇論文中，我們提出了在無線多媒體通訊中基於封包成功率的交遞排序方法。在這個方法中，一個交遞要求的優先順序，將取決於下列三個因素：當下的封包成功率，封包成功率下降的速率，以及其所屬服務類別的封包成功率最低需求。我們所提出方法的主要貢獻在於改善了交遞過程中使用者感受到的服務品質。分析以及模擬的結果顯示我們的方法可以有效的改善交遞失敗的機率以及服務被迫中斷的機率，並且對於新進話務的阻斷機率只有極小的影響。Traditional handoff ordering methods adopt the received signal strength (RSS) as the basis of prioritization. However, the RSS is not the only one metric to represent the user perceived quality of service, since many other factors, like the noise, interference, packet length, and modulation / coding schemes, would also affect it. In this thesis, we propose a handoff ordering method based on packet success rate (PSR) for wireless multimedia communications. The priority of a handoff request is based on its current PSR, the PSR degradation rate, and the minimum PSR requirement of its service class. The major contribution of our method is that we improve the user perceived QoS during the handoff process. The analysis and the simulation results indicate that our method can effectively improve the handoff failure probability and the forced termination probability with little or no increase of the new call blocking probability.Abstract ii Acknowledgments iv I. INTRODUCTION 1 II. BACKGROUND DESCRIPTION 5 III. QUALITY PREDICTION PRIORITY QUEUING 11 3.1 Design Principle from Previous Works 11 3.2 Packet Success Rate 14 3.3 Quality Prediction Priority Queuing 16 IV. ANALYTICAL METHOD 20 4.1 System Model 20 4.2 Call Admission Control of New Calls 22 4.3 Call Admission Control of Handoff Calls 23 4.4 State Transition 23 4.5 Analysis of Priority Queue Methods 27 4.6 New Call Blocking Probability 29 4.7 Handoff Failure Probability 30 4.8 Forced Termination Probability 30 V. SIMULATION RESULTS 31 VI. CONCLUSION 37 REFERENCES 382153037 bytesapplication/pdfen-US無線多媒體通訊連線品質交遞排序wireless multimedia communicationslink qualityhandoff orderingthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/58656/1/ntu-94-R92942075-1.pdf