The Research And Simulation Of Routing Protocol Based On Leach Energy Savings Achieved

Wireless Sensor Network (WSN) is a new network integrating sensor technology, embedded computing, distributed information processing technology and wireless communication into one network, which has the ability to collect data on real-time from the monitored objects in sensing area by operating the sensor nodes working cooperatively, and then to send the data or information to user who is far away from the sensing area. The biggest difference between WSN and the traditional wireless network is that, except for several mobile nodes, most of the nodes of WSN are working in stationary and usually they are working in dangerous environment so that the energy supply module cannot be replaced which is always designed as a throw-away pattern. Therefore, it's significant for WSN to design efficient power control strategy to prolong the life time of network because it's limited by the hardware capacity of the WSN node. In this thesis, we make improvements based on the cluster-head selection strategy and building cluster method of LEACH routing protocol. First, we propose a new saving energy algorithm, named LEACH-GB, of which cluster-head selection depends on the energy grads between two nodes instead of a calculated probability in LEACH.In LEACH-GB, each node of WSN records the energy grads among its adjacent nodes in each round, and then calculates the cluster-head selecting factor with the energy grads. The cluster-head is selected according to the selecting factor. Furthermore, the energy grads is adjusted by the geographic position of the two adjacent nodes and by the signal strength from its partner nodes, and then the energy grads is to be served as the reference index of cluster-head selection to build cluster. Second, we propose LEACH-MM, an energy-aware algorithm based on multi-path and multi-hop. LEACH-MM plots the sensing area in WSN into several parts, in which they are assigned a deterministic cluster-head selection probability according to the distance from the base station. The cluster-head selection is only conducted in the first round, and it's assigned by the late cluster-head according to the resident energy of every node from the second round on. Moreover, LEACH-MM improves the data transport as a multi-hop way which is a single-hop in LEACH. The thesis simulates the two algorithms in NS-2 and evaluates them by comparing the performance with LEACH, of which results show that the two algorithms can save energy in nodes and decrease energy consumption, and hence prolong the life time of WSN.