Dynamic Active Period Allocation with Topology Update Scheme for Low-Power SUN

This paper proposes a low-power multi-hop data-frame transmission scheme to realize a long-lived SUN (smart utility networks) as promoted by the IEEE 802.15 TG4g and MAC modifications in the existing IEEE 802.15.4 MAC in order to support the TG4g PHY amendment assuming its utility in frequency band in Japan. In the proposed scheme, turned-off beacons are employed in the superframe to reduce power wastage due to periodic transmission, and the existing concepts of active and inactive periods in 15.4 MAC are adopted; thus, effective sleep periods for each meter device are assigned. Moreover, the paper proposes an adaptive active period allocation with dynamic re-association for optimizing the allocated active period and achieving low power consumption over the entire system. The results of computer simulation confirm that the proposed system allocates suitable active periods according to frame traffic while maintaining low power consumption. Furthermore, the paper reports on experimental results using the prototype terminals that confirms the proposed scheme effectively expands the service area with multi-hop transmission.