Packet transmission policies for battery operated wireless sensor networks

With the concept of “Cognitive Sense of China” and “Smart Planet” proposed, wireless sensor networking is considered to be one of the most important technologies of the new century. In wireless sensor networks, how to extend battery lifetime is a core problem. In this paper, we address the problem of designing battery-friendly packet transmission policies for wireless sensor networks. Our objective is to maximize the lifetime of batteries for wireless sensor nodes subject to certain delay constraints. We present three packet transmission schemes and evaluate them with respect to battery performance. The first scheme, based on combining multiple packets, utilizes battery charge recovery effect, which allows some charge to be recovered during long idle periods. The second scheme, based on a modified version of lazy packet scheduling, draws smoother and lower current and is battery efficient. The final scheme, based on a combination of the two previous schemes has superior battery performance at the expense of larger average packet delay. All three schemes are simulated for a wireless network framework with internet traffic, and the results were validated.