Realizing safe and reliable vital sings monitoring with wireless body area networks

In this paper, we report development and performance verification of a wireless body area network prototype compliant with the MAC protocol of the IEEE802.15.6 BAN. The relaying functionality which utilizes a relay between a hub and a node is confirmed when a direct path between them is not available due to shadowing effects. The delay due to switching to the relay topology is less than one second. Also, ID-based frequency channel hopping mechanism is introduced and verified to be able to quickly avoid frequency channel interference among BANs. In addition to that, transmission power control with body movement detection is employed to reduce sporadic disconnection through giving an extra amount of transmission power when the node detects a large fluctuation in received power. With functionalities mentioned above, the prototype is expected to be used for medical monitoring applications where requirements for data delay and disconnection are rather severe.