IEEE802.15.4 即時傳送機制

Abstract

新的通訊協定IEEE 802.15.4 針對低複雜度、低成本、低能 量消耗的低功率無線個人區域網路設備提供一個低速的無 線連結。雖然此規格使用保證時槽 (GTS)的方法來提供服務 品質，但在某些限制下，一些急需服務品質的設備卻無法在 緊急情況下使用這個方法。為解決這個問題，我們提出「私 會」機制來改善網路產能、資料延遲時間及封包碰撞率等系 統效能。

The new IEEE standard 802.15.4 provides low complexity, low cost, low power consumption and low data rate wireless connectivity among devices in low-rate wireless personal area networks (LR-WPANs). Though Guaranteed Time Slots (GTS) is a method of quality of service (QoS) provided by IEEE 802.15.4, under some circumstances it suffers from some constrains so that some QoS-needing devices cannot utilize this method. Even GTS is utilized, inflexibility of GTS will degrade the channel utilization. To deal with this, Elopement mechanism is proposed to provide better network performance, such as throughput, delay time, and collision rate.