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.
