Stevenage: The Institution of Engineering and Technology
Recent technological advances in integrated circuits, wireless communications and physiological sensing have allowed ultra-low power, intelligent-monitoring tiny devices to settle around the human body, forming a wireless body area network (WBAN) to collect information for a particular purpose. As these tiny devices are low-weighted and energy-restricted, ‘energy efficiency’ becomes a key issue. Built in 2012 to facilitate the development of WBAN, the ‘IEEE 802.15.6’ standard operates with one-hop star and two-hop restricted tree topologies. Its two-hop extension protocol has relaying nodes (working as a microhub), process node joining and schedule two-hop transmissions, thus reducing their lifetime. To reduce the energy consumption and overhead for relaying nodes, the authors introduce a new two-hop extension protocol which lets the generally better resource-equipped hub directly transmit packets to the downlink relayed nodes. Analytical and experimental evaluations show that when advancing ‘IEEE 802.15.6’ in extending the lifetime of relaying nodes with less energy consumption and overhead, the authors’ new protocol also retains its advantages, including longer lifetime for relayed nodes and lower bit error rates.