Energy efficient methods of encoding destination address to address overhearing problem in BAN

Many duty cycling MAC protocols exploit preamble sampling technique to improve the energy efficiency. In this technique, all the devices periodically listen to the medium for a short duration and then go back to sleep if medium is found idle. When a device wants to send data it transmits a long preamble followed by data bits. When the receiver wakes up and detects the preamble it stays awake until it receives the data. This technique suffers from overhearing problem (i.e. the non target neighboring devices will also overhear the preambles and stay awake until data transmission begins) which wastes energy. To address overhearing problem, XMAC protocol embeds the ID of the target device into the preamble frame which enables nontarget neighboring devices to go back to sleep. The problem with this approach is that the receiver has to demodulate and decode the received frame to recover the destination address which is more complex and energy hungry process than pure preamble sampling. To decode the destination address without demodulating the received frame we encode the destination address as the length of the preamble frame. Thus, by measuring the duration of the preamble frame the receiving device can determine whether it is the intended target of the frame without invoking expensive demodulation process. We derive the energy consumption model for XMAC protocol and compare the performance of the proposed technique against the XMAC. Numerical results derived using the IEEE 802.15.4 compliant CC 2530 radio parameters show that proposed method outperforms XMAC in energy efficiency and latency thereby improving QoS.