Asynchronous Communication Mechanism Oriented Wireless Sensor Networks and MAC Protocols

Abstract

Underlying communication of wireless sensor networks is mainly depending on coordinated sleep/wakeup mechanisms,and is still basing the link layer protocols upon the traditional 802.11.For wireless sensor networks usually having high node density and large scale,802.11 protocol is prone to be not efficient in energy consumption,network throughput etc.Basing on the dynamic links in a large portion of monitoring applications of wireless sensor networks,this paper proposes a kind of weak connection-oriented asynchronous communication mechanism (ACM).Differential from traditional RTS/CTS handshaking mechanism,ACM allows transmitter directly write the data into the low power asynchronous module on receiver while it is sleep. In this way,each node can schedule its own transmission without demanding network synchronization. The result is a store-wakeup-forward,asynchronous communication mode in the network. This paper describes the key factors of ACM and proposes two kinds of MAC protocols for differ- ent applications.Moreover,the diffusion approximation based open queuing model is established to analyze the performance of ACM,proving the throughput of ACM is O(W/(n/logn) ^0.5). Analytical and experimental results show that,compared to synchronous communication mechanism, ACM is able to prolong network lifetime and improve the throughput.