Research On Routing Optimization Algorithm Based On Cross-layer Power Control In Wireless Sensor Network

With the rapid development of cognitive recognition technology, intelligent sensors and identification terminal realize real time measurement, perception and monitoring. The networking of the physical world of and the expansion of information world create a kind of new information acquisition and processing technology (Wireless Sensor Network, WSN). Generally it characters of large-scale, centerless, self-organization, topology changes frequently, limited energy of sensor node and difficult to supplemented. Also the ability of computation and communicate of sensor nodes is very limited. Therefore, it’s a important way to design optimization of energy routing protocol in order to prolong the lifecycle of WSN. In addition, based on the traditional hierarchical communication protocol of routing protocol is very difficult to satisfy the requirements of QoS. Cross-layer optimization strategy is the first choice to improve the performance of routing protocol. Power control for WSN is a kind of cross layer optimization mechanism by dynamically adjusting nodes’ transmission power. In the premise of guarantee the quality of connectivity and QoS, it can extend the network lifecycle as the main target, simultaneously give attention to co-interference between the nodes, transmission latency and load balance. The main research work of this thesis as following:1. In view of the topology changes frequently of WSN and random deployment of sensor nodes, it often appears "hot spot" areas or "island" phenomenon. In this thesis, on the basis of analyzing the routing based on geographical location information, a light level cross-layer routing algorithm based on optimal connectivity power is proposed. The core idea of the algorithm is combined the optimal connected power control mechanism with routing decision. In the premise of guarantee network two-way connected, according to level of nodes’ interference, residual energy and spatial location information in the forward area to dynamically select forwarding nodes. Simulation results show that the algorithm can reduce the energy consumption of communication and intensity of competition between nodes, improve QoS of routing.2. Hierarchical routing protocol improves the network energy utilization through efficient management of nodes and minimum redundant information transmission. Due to the problem of imbalanced forwarding load, leading to the invalid of nodes which forward high load, a load balancing routing optimization based on cross-layer power control is proposed. It takes advantage of betweenness to assess network layer forwarding load. Transmission power of cluster head is made decision by forwarding load of network layer and remaining energy of physical layer in order to form clusters of different size. With minimum energy consumption between inter-cluster routing, simulation results show that the algorithm can effectively improve load balancing and prolong network lifecycle to the extent.