The Research Of Cross-layer Routing Protocols For Wireless Sensor Networks

The sensor nodes of wireless sensor network have small size and use battery-powered. Thus the processing and storage capacity, the communication range, energy and other issues of a single node is limited. However, the adjacent nodes in the shared channel can easily cause collision in data transmission, this not only leads to increase packet loss but also increases the delay and energy consumption caused by retransmission. In the traditional layered protocol architecture, the layers transparent to each other, it maintains the independence of each layer design, while it simplifies the network protocol development and reduces the difficulty of achievement. But it not well adapted to the characteristics of wireless sensor networks, and can not integrate the information of each layers in order to achieve low-collision and energy-efficient. Therefore, this article will research cross-layer routing protocols, and propose a new routing protocol.The research of this thesis is about cross-lay routing protocols of wireless sensor network, and mainly completes the following tasks:(1) This paper describes the routing protocol of wireless sensor network with layered protocol architecture, analyses the advantages and the shortcomings, and induces cross-layer design to solve its shortcomings. Then this paper explains the cross-layer design. Introduces and analyses several routing protocols based on cross-layer design.(2) Designing a new interface in the network protocol architecture. This paper designs new interface functions in the MAC layer and physical layer, and designs a independent logic control unit. So network layer can call the new interface functions through logic control unit to get information of MAC layer and physical layer.(3) Based on cross-layer design proposed a collision-aware energy-efficient routing protocol (CAEE). CAEE routing protocol uses the information obtained by the logical control unit, calculates the collision degree and energy degree of the candidate node in the path as a measure of routing to reduce collision and increase the energy efficiency of the network. To reduce collision in the network, CAEE routing protocol induces collision degree as one of the routing metric to avoid high collision area. To improve the energy efficiency of the network, CAEE routing protocol induces energy degree as one of the routing metric to choose the path of low total energy consumption and high residual energy as the routing. To further reduce energy consumption and reduce collision, this paper uses wireless channel gain symmetry principle, combines the information of MAC layer and physical layer to compute the optimal transmit power. So it optimizes the transmission power of each hop. Simulation results show that the packet loss rate of CAEE is reduced by about 20% compared with AODV. And in the average end to end delay, energy consumption and network lifetime, CAEE has better performance than AODV 10%~20%.