Research And Implementation Of Header Compression Algorithm In Wireless Sensor Networks

Wireless integrated sensor networks, which include collecting, processing data and communication, are used more and more widely for its low cost and convenient deployment. Nowadays the researches of sensor networks are fairly active. Header compression technology can eliminate the redundant information and reduce data transmission volume of the header field, which is an effective way to save the energy consumption and improve the quality of network service. This thesis focuses on the research and implementation of header compression algorithm in sensor networks.The main works are as follows:(1) The thesis proposes a distributed algorithm for the distribution of MAC address in intensive sensor networks with GAF topology, in which the MAC address field of MAC protocol header is too long. MAC address requests to be unique partially rather than globally, so MAC address can be reused in different regions. When distributing MAC address for nodes in the special virtual grid topology formed by GAF algorithm, we can separate clusters and nodes and adopt a different MAC address allocation strategy. The thesis discusses the restrictions and algorithm of the distribution of MAC address for clusters and nodes separately. Theoretical analysis and simulation experiments show that the algorithm can effectively reduce the length of MAC address and can maintain good performance in intensive networks.(2) Based on the analysis of characteristics and compressibility of the header of Active Message Layer and Communication Layer, which are in the protocol stack of TinyOS, the thesis propose a header compression scheme for Active Message Layer and Communication Layer of TinyOS. The compression scheme can significantly reduce the header length by inserting a compression layer in the protocol stack of TinyOS. When the scale of network is smaller, the header compression ratio can reach more than 70%. The compression scheme can be used for the actual sensor networks, applies to the application which uses multi-hop routing protocol for data transmission, supports the nodes which adopt the IEEE 802.15.4 standard, such as Micaz, iMote2 and so on.(3) The thesis designs and implements a header compression prototype system based on Micaz nodes in TinyOS. To make TinyOS support the header compression, the system communication components CC2420RadioM of TinyOS need to be modified. The header compressor is carried out in the command"send"of CC2420RadioM, and the header decompressor is carried out in the event"RXFIFODone"of CC2420RadioM. Based on the hardware platform"the prototype system of data compression key technologies in the asynchronous wireless sensor network environment", which is the National 863 Plan committed by our laboratory, the thesis implements a header compression prototype system in Micaz nodes. The results of comparison experiments show that the prototype system can effectively reduce energy consumption and packet loss rate of the network with small extra storage.