Research On Asynchronous MAC Protocol With High-energy Efficiency For MHR-WSN

As a new type of Wireless Sensor Networks (WSN), Middle and High Rate Wireless Sensor Networks (MHR-WSN) has focused more on large amount of media information, such as the sound, video, still images, etc. So it has great application prospect and research value in the military, public security, medical, industrial, intelligent household and other fields. MAC protocol is one of the important topics in MHR-MAC research. Because asynchronous MAC protocol manage avoiding synchronize scheduling control energy consumption, so it is of a natural advantages on energy efficiency, becomes one of the hot topics in the study of sensor networks technology.This article is intended for the MHR-MAC related project:"The research and implementation of MHR-MAC key technology", in this MHR-WSN environments, the large quantify of diversification network data makes Network energy consumption and Latency problem. So in this paper, asynchronous competitive MAC protocol is studied. The main work and innovations are as follows:Firstly, according to the characteristics of MHR-MAC:heavy and volatility network traffic, a asynchronous wireless sensor network MAC protocol with changing flow prediction is put forward, it first introduced the concept of network flow acceleration, set up the mechanism of network traffic prediction, intelligent projections for network traffic; Then in order to reduce "handshake" energy consumption in classic asynchronous competitive MAC before every communication, a shortest preamble time is added to target node, which makes "one handshake, multiple communication mechanisms" true; Finally the protocol maintains a fixed amount of buffer queue for each node to guarantee the fairness of the agreement.Secondly, in view of that the preambles taking up channel for a long time lead to the low channel utilization and data delay problem in traditional asynchronous MAC protocol competitive, Put forward a asynchronous competitive MHR-WSN MAC protocol with optimization preamble. First a new message control format is come up and a neighbor information table is established for each node. Then nodes self-learning algorithm is designed, finally, broadcasting mechanism is introduced, to estimate the time of sending the preamble and packets starting time. This protocol can effectively reduce the leading carrier wave length, and improve the network energy efficiency, at the same time, reduce the network latency.In view of the special requirement in MHR-WSN, asynchronous competitive MAC protocols is thorough studied and two new asynchronous competitive MAC protocols are put forward:a asynchronous wireless sensor network MAC protocol with changing flow prediction and a asynchronous competitive MHR-WSN MAC protocol with optimization preamble. The simulation analysis show that the proposed MAC protocol is more adapted to MHR-WSN, effectively reduce the network energy consumption and transmission latency.