在無線網路的環境中由於系統資源先天上的限制，使得通訊的服務品質受到影響。在無法無限制的增加系統資源的情況下，使用允入控制去區分訊務的優先權，將能使即時性較高的訊務得到較好的服務品質。 傳統的允入控制法則僅區分新訊務(new session)及換手訊務(handoff session)，在現在網路服務的多元下已不敷使用，因此本論文提出了一個新的演算法則，除了區分是否為換手訊務外還增加了區分訊務類型 ─ 資料、語音、視訊會議，以保持通話或是會議的連續性。並使用模糊推論系統(Fuzzy Inference System-FIS)來動態調整允入控制的門檻值，藉此以達到比傳統保留固定頻寬的方式，有更佳的系統使用率。 The communication quality is deeply influenced due to the resource limitation of wireless network. Under this situation, we can use call admission control(CAC) to provide better QoS for real-time traffic by prioritizing different type of service. Traditional CAC schemes only prioritize the priority between new call and handoff call and reserve fixed amount of bandwidth for high priority traffic. It is not suitable for the present network environment which contains several kinds of service. On the other hand, reserving fixed amount of bandwidth will result in worse usage of basestation(BS) bandwidth. Thus, we propose a CAC scheme which incorporates multiple traffic types and adjusts the admission threshold dynamically using fuzzy inference system(FIS) to achieve better usage of BS resource.
