Tightly integrating activity scheduling for wireless sensor networks

In wireless sensor networks, one of the main design challenges is to save severely constrained energy resources and obtain a long system lifetime. Low cost of sensors enables us to initially deploy a large number of sensor nodes in a very high density. Thus, a potential approach to solve a lifetime problem arises. That is to schedule sensor nodes work alternatively by configuring some of them an off-duty status that has lower energy consumption than the normal on-duty one. In a single wireless sensor network, sensors assume two main functionalities: sensing and communication. Minimizing energy consumption in a highly dense wireless sensor network needs to maximize off-duty nodes in both domains. Most of the previous work addressed only one kind of redundancy: sensing or communication alone. Based on our previous conclusion: "the communication range is twice the sensing range" is the sufficient condition and the tight lower bound to ensure that complete coverage preservation implies connectivity among active nodes, if the original network topology (consisting of all the deployed nodes) is connected, we study a node status configuration strategy in a tightly integrated two-phase mode for those sensor networks where the communication range is more than twice the sensing range by comparing this strategy with the other two in the term of off-node number, the experimental results show that it leads to more off-duty nodes in double domains without incurring the reduction of off-duty nodes in a single domain.