ENERGY EFFICIENT WIRELESS SENSOR NETWORK, NODE DEVICES FOR THE SAME AND A METHOD FOR ARRANGING COMMUNICATIONS IN A WIRELESS SENSOR NETWORK

摘要

The application relates to a node device (1101) for a wireless sensor network. The node device comprises a wireless transceiver (1151) adapted to exchange information with other node devices on a communications frequency according to a time slotted channel access scheme, and a controller unit (1141) adapted to control the wireless transceiver (1151). The controller unit (1141) is adapted to selectively tune the wireless transceiver (1151) to a first frequency for receiving cluster beacon signals from a headnode of a cluster of the wireless sensor network and to a second frequency for receiving network beacon signals. The controller unit (1141) is additionally adapted to detect, which parts of a multi-part beacon signal were successfully received, and to use said detection for deriving an estimate of a distance between the node device and a device that transmitted said beacon signal.