Research And Improvement Of RPL Routing Protocol

Wireless sensor networks are composed of a large number of micro wireless sensors with communication function,which have broad application prospects in intelligent transportation,smart home,smart agriculture and other fields.With the development of the Internet of things industry,Internet and wireless sensor networks are combined together which become an inevitable trend.As the IPv4 address runs out,IPv6 addresses have abundant resources and meet the needs of Internet.In order to solve the problem of routing and network in IPv6 over Low-power Wireless Personal Area Networks(6LoWPAN),Internet Engineering Task Force(IETF)establishes the Routing over Lossy and Low-power Networks(RoLL)working group,which evaluates OSPF,OLSR,RIP,AODV etc.Then they plan IPv6 Routing Protocol for Low-power and Lossy Networks(RPL).Therefore,this article analyzes the performance of RPL and verifies it on the hardware,and finally puts forward Chinese Remainder Theorem(CRT)-based RPL routing protocol.First of all,the thesis tests the performance of two metrics for RPL by the Cooja simulator,which analyses the energy consumption,packet delivery ratio,average end-to-end delay and throughput deeply.The result shows that the performance of expected transmission count(ETX)metric for RPL routing protocol is relatively better.Then the contiki operating system is transplanted to the hardware devices.This device mainly uses stm32f103 as the base plate and stm32w108 or cc2530 as the core chip.In this paper,the stm32w108 chip or cc2530 chip comes with radio frequency,the function of the chip only acts as forwarding the packet.On the hardware,ETX-based RPL routing protocol is tested and verified by the network.Finally,according to the shortcomings of RPL routing protocol,CRT-based RPL has been proposed.The original data packets are divided into slices,which are transmitted over multiple paths concurently.The destination node reassembles the split data packets.The analysis shows that the proposed routing protocol is improved in terms of packet delivery ratio,average end-to-end delay and energy consumption.