Towards RF Communication and Multiple Access Protocols in a Body Sensor Network

A Body Senor Network (BSN) allows the integration of miniaturized, intelligent, low power, invasive, and non-invasive wireless sensor nodes to monitor body function and the surrounding environment. The inclusion of wireless sensor nodes within the body requires many more constraints to be met for safe and reliable operations. In this paper, we first study the possibility of Radio Frequency (RF) communication to an implanted device. Then we provide a simulation study of various multiple access protocols for a non-invasive BSN. For RF communication, we use a Perspex tank that mimics the electrical properties of the body at 400MHz. The results show that the implant reveals best performance at 3cm depth and not close to the surface of the skin. Furthermore, we analyze the performance of a Preamble-Based TDMA (PB-TDMA), S-MAC, and IEEE 802.15.4 protocols for a non-invasive BSN using NS-2. Simulation results show that IEEE 802.15.4, when configured in a beacon-enabled mode, performs better than S-MAC and PB-TDMA. Our results also suggest the design and implementation of a new lowpower multiple access protocol for invasive and noninvasive BSN.