Reliability Enhanced RPL for Wireless Sensor Networks

In this paper, we investigate the problem of reliability of RPL (IPv6 Routing Protocol for Low power and Lossy Networks) when applied to route traffic in Wireless Sensor Networks (WSNs). RPL is a routing protocol adapted for information routing with low power, low storage and processing sensor devices. However, there are two problems when RPL runs with ND (Neighbor Discovery) and uses the link metric such as ETX. First, loops may occur in some situation. Second, lack a mechanism to refresh the life time of a neighbor. In this paper, two mechanisms, Loop Avoidance (LA) and Neighbor Life Time Refresh (NLTR) are proposed to resolve these problems. The simulation results show that Loop Avoidance mechanism and the Neighbor Life Time Refresh mechanism can enhance the performance of the entire network significantly. Especially using these two mechanisms together, the performance of entire network is the best. These two mechanisms can effectively improve the reliability of RPL.