Battery-Friendly Packet Transmission Algorithms for Wireless Sensor Networks

The core problem with nodes of wireless sensor networks is the limited charge capacity for the power-operated battery. The main concern of this paper is how to extend the battery´s lifetime. According to the characteristics and functionality of sensor nodes, the sensor applications are categorized into three distinct types, i.e., the hard real-time applications, the soft real-time applications, and the periodic applications. For the hard real-time applications, a battery-friendly lazy packet scheme is designed to draw smoother and lower current for minimizing battery charge consumption. A battery-friendly local optimization scheme with slack time is exploited and evaluated for the soft real-time applications. For the periodic applications, a battery-aware task-scheduling algorithm is developed, which reschedules tasks of sensor nodes to achieve the battery friendly discharge profile. The simulation results show that the three battery-friendly algorithms perform better in extending lifetime of battery-operated sensor nodes and minimizing battery charge consumption.