The Research And Application Of Cross Layer Optimization On Wireless Sensor Network

With a lot of applications for wireless sensor network in real life, research of cross layer design on wireless sensor network also gradually becomes the hot research issues for the researchers. The cross layer design on wireless sensor network takes the whole system as an integral structure and solves the limitations of the traditional separate layer design. The most of wireless sensor network nodes take battery as power supply, so the energy is very limited. So finite energy is the first consideration in the cross layer design of wireless sensor network above all problems. In the research of how to reduce energy consumption, power control technology and the time synchronization technology is very important two kinds of technologies in wireless sensor networks.Power control technology has great potential in the ascension of wireless sensor network data flow.There are many researches on power control technology, the current power control technology is mainly by increasing the transceiver or design of complex MAC layer protocol, to achieve the goal of preventing collisions and increasing the network traffic. This paper puts forward a power control mechanism based on the simple rough set theory; the method can effectively reduce the data collision and improve the data flow in wireless sensor network.Time synchronization algorithm is also is one of the key technologies research in the wireless sensor network and how to find out a time synchronization mechanism that is application-based, simple and effective is the key research in wireless sensor network. In this paper, a time synchronization mechanism applying to wireless grain monitoring system based on post-facto is put forward. According to the practical applications, network run well and data transmission do not have the problem of collision retransmission. In this paper a time synchronization algorithm based on the clock self-correction is proposed.the contrast experiment results validate that the method can prolong the time synchronization between the nodes and have a large application value.The main contents are as follows:(1) An introduction is made which includes the background, implementation and research status of cross layer design. The paper discusses the principle、solution and the advantage of cross layer optimization technology and analyzes the key technology of the wireless sensor network cross layer optimization.(2) The power control methods of cross layer optimization technique are introduced in this paper, analyzes the principle of power control technology, power control technology is studied by using rough set theory, and do the simulation analysis to wireless sensor network power control technology by the NS2software.(3) A time synchronization mechanism based on post-facto is put forward. And the introductions of synchronization mechanism makes in detail, the paper also do a research of a time synchronization algorithm based on the clock self-correction by the hardware.(4)Time synchronization mechanism are mostly based on use, the paper design a grain monitoring system based on post-facto, and it also presents the detailed design of the software and hardware of the node and give the environment and results of system application.Finally, the power control technology and time synchronization technique is the key wireless sensor network technology based on the application. The simulation and application on system show that the proposed power control algorithm and the clock synchronization algorithm can be used well in the actual wireless sensor network environment, meet the requirements of the wireless sensor network and has certain practical value.