Research And Implementation Of The RPL-based Clustering Routing Protocol In Wireless Sensor Networks

Wireless sensor networks (WSNs) are composed of a large number of low-cost, low-power micro sensors, which have the ability to sense, compute, and communicate. With the large-scale deployment of WSNs and the application scenarios becoming more complex, better performances of routing protocol are required. On the basis of studying existing routing protocols in WSNs, this thesis proposes an RPL-based clustering routing protocol, and carries out the implementation and verification.Firstly, this thesis introduces low power lossy networks IPv6routing protocol (RPL). The detailed analyses on route building process and routing strategy are introduced. And the performance of RPL is evaluated through Cooja simulation platform, in terms of networking process, trickle mechanisms, network restoration and node energy consumption.Then, an RPL-based clustering routing protocol is proposed. This protocol gives a novel cluster head competition mechanism by using some parameters of RPL. In this mechanism, the distance to the gateway, the remaining energy of node, link status and distribution of the cluster head are considered, in order to reduce the maximum hop of network and make the RPL routing tree more flat. The proposed protocol also adopts cluster head rotation mechanism driven by the changes of nodes’optimal parents to balance the energy consumption of nodes, and to further improve the network load balance. This paper describes the design ideas and key mechanisms of RPL-based clustering routing protocol, as well as the process of routing build. Futhermore, the implementation of the proposed protocol based on Contiki is detailed in this thesis, including the data structure and main functions.Finally, the test environments are built both on Cooja simulation platform and micro sensor node MSN-213to verify the feasibility of RPL-based clustering routing protocol. The results show that1) sensor nodes using this routing protocol can build clusters and join the network rapidly;2) the gateway sensor nodes can also receive data packets normally; and3) the network can complete the repair process automatically when a node failure happens.