WCDMA蜂巢式系統中提供多速率服務之類神經乏晰呼叫允諾控制

Abstract

寬頻分碼多工擷取(WCDMA)的技術，應用在第三代行動通訊(3G)的時代裡。許多企業投入大量資金以及人力在研發WCDMA蜂巢式系統，祈望能使得通訊系統更有效率。為了達到此目的，要設計一套合適的呼叫允諾控制方法，才能改善效能並且保障系統的服務品質。由此可知，設計WCDMA呼叫允諾控制方法對於通訊系統是相當重要的。我們提出一套類神經乏晰呼叫允諾以及傳輸速率控制(NFCAC-RC)的方法，經由考慮系統的通訊中斷率、預測的系統干擾量、使用者對周遭通訊的影響，NFCAC-RC可以保障系統的服務品質，並且提高系統的使用率。 再者，我們考慮不同形式的資料使用者對系統的影響。當系統充斥著傳輸大量資料的使用者時，要保障系統的服務品質就不是一件容易的事。NFCAC-RC採用控制傳輸速率的方法來克服這種情況，而模擬的結果也顯示NFCAC-RC能夠有效的提升系統的效能。

Wideband code division multiple access (WCDMA) is used as a radio interface for the third generation (3G) mobile systems. Many venders invest in lots of money and people on WCDMA cellular systems. What venders consider is the performance of the system. A good call admission control (CAC) scheme can improve the performance and maintain the quality of service (QoS) requirements of the system. To design a suitable CAC scheme for WCDMA cellular systems is important and necessary. In this thesis, we propose a neural fuzzy call admission and rate control (NFCAC-RC) scheme. Considering the outage probabilities of all services, forced termination probability, the interference mean at the next time instant, and the influence of a call request on the adjacent cell, NFCAC-RC guarantee the QoS requirements and maximize the utilization of the system. In addition, we consider the influences of different data source models in the system. When the system is heavily loaded with bursty data traffics, it is hard to maintain the QoS requirements. NFCAC-RC overcomes this situation by adopting rate control. Simulation results show that NFCAC-RC can improve performance.