一种应用于多跳网络的可调占空比固定时延MAC协议

Fixed delay MAC protocol with changeable duty cycle applied to multi-hop networks

针对Ad Hoc网络、无线传感器网络等类型的多跳网络中使用传统的基于低占空比的MAC协议会使数据传输的时延随转发节点的增加而变大的问题,提出一种固定时延的MAC协议(FDS-MAC).该协议针对不同跳数的源节点,由汇聚节点通过改变占空比来设置合理的固定时延值并将其放在调度表中,源节点通过改变监听调度表的占空比达到固定时延的目的;当节点跳数较多时,可通过物理分簇配合FDS-MAC有效降低固定时延的值.理论分析和仿真结果表明,该协议可获得合理的固定时延和良好的耗能特性,在很多场景可获应用.

In order to solve the problem that the transmitting delay increases with the increment of forward nodes which is based on low duty cycle in MAC （media access control） protocols of multi-hop networks such as Ad Hoc or wireless sensor networks,the FDS-MAC（fixed delay S-MAC） protocol which has fixed delay in data transmission is proposed in this paper.The value of fixed delay is determined by the sink nodes.The source nodes transmit the data with fixed delay according to the duty cycle of the schedule from the sink.By adjustment of the duty cycle,the value of fixed delay can also be changed.When the number of hops is large,the FDS-MAC can reduce the value of fixed delay by clustering.The theory analysis and simulation results indicate that the reasonable fixed delay and good performance in energy consumption are obtained and the protocol will be applied widely.