Study On Energy-Saving Routing Algorithm Based On Network Layer Of LR-WPAN

ZigBee technology is a low data rate, low power consumption, low cost, high reliability wireless networking protocol, it could be used to construct large-scale network. ZigBee targets toward industrial controls, intelligent home, medical care, military operations and security systems. IEEE 802.15.4 committee and ZigBee Alliance joint together to start working on a low data rate network standard. IEEE 802.15.4 focuses on the specification of lower two layers of the protocol: physical layer and media access control layer. ZigBee Alliance aims to provide the upper layers of the protocol stack:network layer and application layer. So far, saving energy is the main issue of LR-WPAN research. Saving energy is an eternal topic, and it is considered to be crucial in low-carbon living.By learning each layer of ZigBee technology, depth-studying on route algorithm of network layer, reading a large number of references about ZigBee routing algorithm, and analyzing the characteristic about ZigBee routing, we proposed some new research points in this paper. a) A new optimal routing algorithm for RN+ node is proposed according to RN+ node performance. The algorithm reduces the overhead of network effectively, and prolongs the life span of network, because it makes the RN+ node change the manner of routing when it has a little remaining energy, so that, it couldn't make the network unavailable. b) A cluster label-based routing strategy has been proposed. The algorithm makes the FFD node in the network choose the routing algorithm according to the cluster, and optimizing the network routing. The algorithm saves some power consumption, saves network energy, and prolongs the life span of network.This thesis consists of five chapters:The first chapter is introduction, in this part, Wireless Personal Network and Low-rate Wireless Personal Network were introduced. The research developments for several key contents, important research objectives and applications were summarized. The main research work and the chapter structure of this thesis were specified.In the second chapter, the IEEE 802.15.4/ZigBee protocol was introduced. They are the physical layer and media access control layer in IEEE 802.15.4 standard, the network layer and application layer in ZigBee specification respectively. The corresponding theories provided research foundation for the following chapters.In the third chapter, a routing algorithm research for network energy optimization based on node characteristics of LR-WPAN was proposed. In this chapter, firstly we introduced some routing algorithm about ZigBee network level, which contained AODV routing algorithm, AODVjr routing algorithm, and cluster-tree routing algorithm. Then we summarized some reference about ZigBee routing, and proposed an optimal routing algorithm for RN+ node, which is called F-ZBR. The algorithm reduces part of redundant RREQ by controlling the number of hop as well as the direction of RREQ packet; and makes the RN+ nodes change the routing manner by defining the minimum routing energy, which makes RN+ nodes save energy when they have a little remaining energy; we add energy flag in RREQ packet, which could help the destination node choose the path without low energy nodes. When there is low energy node in the path, the energy flag would be changed to 1. We analysis the F-ZBR algorithm according to the simulation results, which are compared with ZBR in packet delivery ratio, available nodes ratio as well as remaining energy ratio.In the fourth chapter, an algorithm based on cluster was proposed for ZigBee mesh network. In this chapter, firstly we summarized the main idea about cluster in ZigBee network, and then introduced a good manner about clustering, an algorithm named ZCLR was proposed. This algorithm assigns the role of node in the network based on the node characteristics. ZigBee Router nodes that are apart from ZigBee Coordinator with odd hop(s) will apply AODVjr algorithm to be the RN+ nodes; while the ZigBee Router nodes that are apart from ZigBee Coordinator with even hops will form a new cluster. Based on the cluster we add some information to control the direction of RREQ. We analysis the F-ZBR algorithm according to the simulation results, which are compared with ZBR in end-to-end delay, packet delivery ratio, remaining energy ratio as well as energy consumption of the cluster-head node.In the last chapter, a conclusion for the entire thesis was made. And the issues that needed to be investigated and solved in the future research on LR-WPAN were pointed.