Research And Implementation Of Cross-layer Protocol For Energy-saving Wireless Sensor Networks

Combined sensor technology with network technology, wireless communication technology and MEMS technology, Wireless sensor networks is a striking and multi-disciplinary hot spots field. Given the wireless sensor nodes are usually placed in hostile environment where people are inaccessible, and the power of the nodes can not be replaced. Therefore, energy saving should be considered as a key problem on the process of hardware and software design, deployment and operation of the nodes.Current energy-saving study of wireless sensor networks are mostly based on hierarchical structure, energy-saving research based on this structure are mainly local optimization, there are obvious limitations about these research, and it is difficult for them to achieve better result of prolong the network lifetime. Because energy is a cross-layer problem, which throughout all the layers of wireless sensor networks protocol stack, so, energy consumption of every layer have to be optimization synthetically when considering the energy optimization of the wireless sensor network, so as to achieve the purpose of energy-saving maximization of the networks.The necessity ,design principle and method of cross-layer design of wireless sensor networks were analyzed first in this paper, requirement of protocol stack's layer for cross-layer was discussed, and representative energy-saving wireless sensor network protocol were illustrated. Then, the protocol of clustering cross-layer routing based on TDMA time slot optimization was proposed, build the energy-saving algorithm by optimizing the cluster head select algorithm and establishing optimal TDMA time slot allocation table, and comparation was done between LEACH algorithm and cross-layer algorithm by using MATLAB energy modeling and simulation.the simulation results showed that cross-layer algorithm has better energy-saving performance.Afterward, software solutions of sensor network nodes which made up of CYRF7936 as RF module and Atmega128L as MCU was designed, the main contents of the design include the SPI driver of CYRF7936, application program of CYRP7936, interrupt program and related protocol program. At last ,TOSSIM simulation tool was used to simulate the topology of wireless sensor networks and the establishment of routes based on cross-layer protocol.