A Predictive Media Access Control Protocol for Energy Efficient Wireless Sensor Network for E-health Applications

Abstract

The formula E = Pt (energy = power multiplied by time) still hold true as we forge ahead in our unending quest to extend power lifetime in e-Health devices that utilizes Wireless Sensors Network as a medium for communication. The key to effective power conservation is encapsulated in the MAC layer of every Wireless Sensor device; therefore, this research work focus on the effect of predictive manipulation of IEEE 802.15.4/ZigBee protocol sleep behaviour. The research work uses predictive manipulation of IEEE 802.15.4/ZigBee protocol; this involves powering on and off the wireless radio at predetermined intervals for maximum energy utilization, coupled with the ability of each node to predicatively send messages only to predetermined nodes. The research work optimizes IEEE 802.15.4/ZigBee protocol for use in low powered Wireless Sensor Networks to relay collated health data from e-Health devices attached to patients, especially in Nigeria where power supply is epileptic. Different MAC layers were examined; however, the popularity and suitability of IEEE 802.15.4/ZigBee protocol made it the preferred choice for modification. OPNET 14.5 simulator was used to capture wireless sensor attributes such as battery power, transmission energy, receive energy, wake up energy, idle energy etc. of physical wireless sensors. Three different simulations of MICAz motes were conducted using OPNET 14.5. Analysis of simulation results revealed an astonishing level of energy efficiency in Wireless Sensor Networks can be achieved through predictive manipulation of sleep periods, which drastically reduces energy consumption in nodes. On the other hand, mathematical models equally back up results obtained via OPNET network simulator. All this has been made possible through predictive manipulation of existing IEEE 802.15.4/ZigBee protocol via PM-MAC algorithm. Finally Predictive algorithm can be folded into most popular protocols in order to extend energy lifetime in Wireless Sensor Networks. e-Health devices in remote areas also can double or triple their operating time before batteries are either replaced or recharged.