1. A method of self-organizing sensor nodes in a wireless sensor network (WSN), the WSN comprising a plurality of sensor nodes in communication with a master node, the method comprising: distributing/installing the sensor nodes in an environment at predefined absolute locations, wherein two of the sensor nodes are anchor nodes of known ID and absolute locations; configuring each of the sensor nodes to in turn broadcast consecutive messages at a plurality of pre-defined and incrementally increasing power levels; detecting receipt of the broadcasted messages at each of the sensor nodes and notifying the master node as to the identity of each sensor node receiving the broadcasted message and the power level at which it was received to define a detected neighbourhood for each sensor node; determining relative locations of the sensor nodes with the detected neighbourhoods; and mapping relative locations of the sensor nodes by the master node based on results of the neighborhood detection and the known locations of the two anchor nodes.