ENOCH: ENabling On-body network Contention Handling

Body area networking is an important segment of the wireless landscape, connecting a growing range of devices such as fitness trackers and smart watches using short range wireless links. However, conventional wireless technologies such as BLE and ANT provide poor support for low-latency applications such as haptic feedback due to their dependence upon duty-cycling to maintain acceptable power consumption. Recent physical-layer design efforts introduce a low-power alternative by establishing capacitively coupled communication through the human body. This mitigates duty-cycling requirements, but results in channel access times similar to those found in more conventional wireless networks, failing to provide adequate latency guarantees even for modestly sized networks. We address this problem by introducing ENOCH, an ultra-low power 12 MHz receiver that relies on capacitive coupling to establish a fieldbus-like through-body network. ENOCH delivers a sub-μW receiver, 10 kbps link-layer throughput, traffic prioritisation, 97% baseline reliability and 7 ms latency in a 7-node network, regardless of contention for the channel. Our design is simple and uses only commercial off-the-shelf components. As it requires neither large antennas nor crystal oscillators, we believe that further miniaturization beyond the current 1 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> hardware/software prototype is possible.