The Study On Cross-layer Energy Conserving Algorithm In Wireless Sensor Network

As the result of combination of sensor, micro-electronics and wireless communication technologies, wireless sensor network has become an active branch of computer science. It has been widely applied to military and civil applications. It consists of a large number of low-cost, low-power and tiny sensor nodes, which have some computing and self-organizing capabilities. Sensor nodes usually carry limited power sources, which are difficult to replace owing to their working environment. Therefore, the primary problem for wireless sensor network is how to determine the most efficient way of conserving the energy of power source to maximize its lifetime.Most of recent energy conserving algorithms are based on layered network model, which only focus on the individual layer issues and ignore the importance of interworking between different layers in a wireless sensor network. Such single layer approach results in inefficacy and wastes source. Wireless sensor network is an application oriented network, so to design general communication protocols for wireless sensor network isn't appropriate. This paper researches and implements an algorithm of data fusion based on cross-layer scheduling, which is a cross-layer energy conserving algorithm. On the basis of former layered model, it jointly designs the protocol of MAC and network layers to make each layer use the information of others, which conserves more energy.The algorithm of data fusion based on cross-layer scheduling makes a collision-free data transmission schedule and sets appropriate slot of time for every data link according to the routing-tree. Therefore, every sensor node can set appropriate waiting time to avoid the collision of brother sensor nodes at same level owing to their same waiting time. This improves the efficiency of muilt-level data fusion. The proposed cross-layer energy conserving algorithm is compared with S-MAC by simulation in OMNET++. Simulation results show that the algorithm provides significant energy savings, latency reduction and throughput increase.