传感网络低占空比MAC协议同步机制研究

低占空比MAC协议通过节点休眠有效延长了传感网络的寿命,然而同步过程中许多节点监听多个计划,降低了协议的节能效果;同时节点休眠导致数据转发时延大大延长。提出了一种适用于低占空比MAC的新同步机制。基站成为唯一的同步发起者,它周期性地发布同步信息。其他节点仅监听一个计划并广播他们自己的休眠计划,多跳路径上的邻居节点交错监听周期。在一个树型拓扑网络上的仿真试验表明,此同步机制可以在更少能量的条件下进一步减少低占空比MAC的系统时延,提高网络在较重负载下的吞吐量。

Research on Synchronization Scheme of Low-duty-cycle MAC Protocols of Sensor Networks

It has been proved low-duty-cycle MAC protocols can significantly prolong networks lifetime. However tests showed that many nodes followed two or more schedules in a large multi-hop network,which caused more energy dissipation. At the same time,sleep incurred a latency penalty in a multi-hop network because packets must wait for the next listen period for transmission. A synchronization scheme of sleep schedule was proposed; the sink node is only synchronizer and periodically sends synchronization information,other nodes just follow a schedule and broadcast their schedule,and the neighbor nodes stagger their schedule phase on a multihop path. The proposed synchronization scheme was evaluated through ns-2 simulation on a tree topology. The results show that the scheme accomplishes the goals of reducing energy consumption and latency in sensor networks.