A traffic-load adaptive power-conserving MAC protocol for wireless sensor networks

Wireless sensor networks are mainly designed for environment monitoring. The lifetime of wireless sensor networks depends on the durability of the battery resource sensors, so it is crucial for sensors to efficiently use their limited battery resources. The energy expends by sensors in data communication makes up a significant quantum of their total amount of energy consumption. In the existing research, most of the power-saving medium access control protocols reduce energy consumption by putting periodically sensors to sleep mode. Such a regular active/sleep schedule fails to adjust individual sensor sleep duration according to per-sensor communication traffic-load, which causes unnecessary idle-listening problem and low power-efficiency. In this paper, we present a new power-saving medium access control protocol for saving power in a wireless sensor networks. This proposed protocol dynamically adjusts the active/sleep time duration of each sensor according to per-sensor communication traffic-load. Meanwhile, it can lead to much greater power-efficiency by prolonging the sensors sleeping duration, when in a sensor network at per-sensor communication traffic-load is low. The basic idea of this proposed protocol is an analytical model for estimating the accurate per-sensor communication traffic-load in a wireless sensor network and a grid-based quorum concept for regular active/sleep schedule.