基于链路预测和网络编码的MAC机制

提出了基于链路预测和网络编码的MAC协议，在EasiLQE的基础上给出了基于窗口自适应的改进EF滤波器的链路质量预测方法，采用自适应周期的主动探测，增加网络环境稳定时的估计准确性，采用了瞬时主动探测模块，在保证估计稳定性的前提下提高了突发状况下的反应速度。在改进链路质量估计方法的基础上，给出了一种新的MAC协议。在协议中合理地利用了无线网络中已经存在的广播特性，在路由算法确定的路由周围增加高阶辅助节点，从而明显增加了网络编码机会，同时又不会引发由流量集中带来的诸多问题。最后讨论了MAC机制中最优的阶数，在编码机会和能量效率上寻求到一个较为合适的平衡点。实验证明，所提MAC协议能够在不集中流量的前提下合理利用节点的过度侦听提高编码机会，增加网络的吞吐量。

MAC mechanism based on link prediction and network coding

A MAC mechanism was proposed based on network coding and link prediction for wireless sensor network. Firstly, an adaptive-window scheme was given based on EasiLQE which uses improved EWMA link quality estimation method and combines the methods of hardware and software, so the accuracy is increased.As a result of the instantaneous active detection, reaction rate became more rapid when unexpected situation was occurring in the network. Secondly, a MAC protocol was improved based on the existing MAC protocol. In the protocol improved, high-level secondary nodes around the path determined is increased by the routing module using the broadcast nature of wireless networks that already exists rationally, so that significantly increased the network coding opportunity, without many problems caused by the concentrating flows. Finally, to seek a more appropriate balance between data diffusion and coding opportunities, the optimal factor was discussed. Experiment results show that this improved MAC protocol can increase network throughput and balance the load of the whole network effectively by using over-heard of nodes rationally, without causing concentrating flows at the same time.