An efficient approach for sensor deployments in wireless sensor network

In wireless sensor networks, the number of sensor nodes has direct relation to the cost of total wireless sensor networks, and at the same time, the problem is closely connected to wireless sensor networks´ performance, such as robust, fault-tolerance, and furthermore, it is considered at first as wireless sensor networks are designed. Therefore, the research on the number of sensor nodes has significant meanings of theory and practice to design of wireless sensor networks. By computation and analysis, the sensor deployments in the form of equilateral triangle, as a rule, are better than those in the form of square, and the efficient coverage area ratios decrease with increasing number of sensor nodes. Sometime information is incompletely monitored or undetected. This is coverage and connectivity problems. The coverage problem is also one of basic problem in wireless sensor networks. The paper analyzes several sensor deployments and computes their efficient coverage areas and their efficient coverage area ratios. In addition, the relation between the number of sensors and efficient coverage area ratio is discussed.