Automatic Beacon Period Contraction for Energy Efficient WiMedia MAC

The basic timing structure for data exchange in WiMedia UWB MAC is a superframe composed of beacon period and data transfer period. When a new device joins the WiMedia UWB based network, the device has to send a beacon in a randomly selected beacon slot in the beacon period. Accordingly, when devices join or leave the WiMedia based network, they may result in idle beacon slots in the beacon period. The idle beacon slots should be removed to spare more time resources to the data transfer period, since no data exchange is permitted during the beacon period. This paper proposes an automatic beacon period contraction scheme which has objective of minimizing the waste of wireless resource in WiMedia UWB based home networks. The proposed method compresses the beacon period in a simpler and faster way than the conventional beacon period contraction algorithm defined in WiMedia MAC standard. Performance evaluation by computer simulation shows that the proposed scheme improves wireless channel utilization efficiency. The results of this paper can be applied to design and implementation of WiMedia MAC with small overhead for UWB applications.