Study of routing metrics for low power and lossy network

Recently, wireless sensors networks (WSN) have become a subject of interest for many different applications. This type of network is composed of a large number of small nodes called sensors; are relatively limited in terms of energy, memory, computing power and throughput. These specific features require a specific routing protocol for WSN, among the routing solutions studied and proposed, the RPL (Routing Protocol for Low Power and Lossy networks) is one of the best candidates. RPL routing was proposed by IETF's ROLL (Routing Over Low Power and Lossy Network) working group. RPL constructs an acyclic graph called DODAG (Destination Oriented Directed Acyclic Graph); which is itself divided into acyclic sub-graphs called DAG (Directed Acyclic Graph) allowing to establish the routes towards the sink. DODAG is built mainly on the objective function. In particular, this objective function determines metrics are taken into account to determine the best route. This paper presents energy-aware routing metrics of RPL, thus a comparison between these metrics. The mono-criterion metric comparison shows that the metric EngConi presents the minimum value of energy consumed by comparing it with EngResi and ETX; And for multi-criterion metrics, the metric ELT has the minimum consumption value.