Research And Improvement Of Routing Metric Based On RPL

The network topology setup and data transmission of nodes in wireless sensor networks can not be separated from the support of routing protocol. The Routing Over Low-power and Lossy network(ROLL) Working Group in IETF has proposed the IPv6 Routing Protocol for Low-power and Lossy Network(RPL). RPL uses link quality(ETX) as single routing metric for default route selection. This kind of metric ensures the transmission quality. However, the network topology can not make dynamic adjustment according to the routing metric when individual nodes have excessive power consumption because of load imbalance. The life time of networks possibly be shortened by those heavily used nodes.A new routing metric named Energy Aware Metric(EAM) is proposed in this paper by combining the energy consumption situation with link quality ETX. The use of EAM makes it possible to consider both link quality and residual energy of nodes as routing metric. By using EAM, the relative balance of energy consumption between nodes is achieved. We use ETX and EAM as the routing metric respectively to perform simulation experiments. Simulation results show that the EAM has worked in improving the energy consumption and prolonging the life time of networks.