LLN中基于环路避免的高效路由修复算法

针对低功耗有损网络(low power and lossy networks, LLN)中现有路由修复算法存在控制开销冗余、修复时延较大和路由环路等问题,提出一种LLN中基于环路避免的高效路由修复算法(highly-efficient loop-free based repair routing protocol for LLN,HLR-RPL)。该算法提出了3个优化思路:首先,采用一种修正后的面向目的地的有向无循环图(destination oriented directed acyclic graph, DODAG)信息请求消息(DODAG information solicitation amend, DIS-A),使得链路中断通告过程和寻路过程同时进行;其次,提出一种减少控制消息回复机制,避免所有接收到DIS-A消息的节点均回复DODAG信息对象消息;最后,提出一种链路中断节点的子节点切换机制,从而优化了网络拓扑。仿真结果表明,HLR-RPL算法在控制开销和路由修复时延等性能方面优于现有的路由修复算法,且能够彻底避免路由环路的产生。

Highly-efficient routing repair algorithm based on loop-free for LLN

To deal with the problems that the existing routing repair algorithms in low power and lossy networks (LLNs) have the control overhead redundancy, large recovery latency and routing loops, a highly-efficient loop-free based repair routing protocol for LLN(HLR-RPL) is proposed. This algorithm mainly carries out three optimization schemes. Firstly, it adopts a new destination oriented directed acyclic graph (DODAG) information solicitation amend (DIS-A) which makes the process of link interruption notification and the process of path finding carried out simultaneously. Secondly, a mechanism of reducing the control overhead is proposed to avoid all the nodes reply the DODAG information object message when receiving a DIS-A message. Finally, a sub-nodes switching mechanism of the link broken node is proposed which optimizes the network topology. The simulation results show that HLR-RPL outperforms the existing routing repair algorithms in terms of control overhead and routing recovery latency. In addition, it can avoid the routing loops thoroughly.