Patent ID: 8842598

Claim:
A method of sending a communications signal in a communications network comprising a plurality of nodes assuming alternating sleeping and waking states, a sender node executing a step of sending an initial preamble, prior to sending data to a destination node, said destination node being a 1-hop neighbor of said sender node, wherein the initial preamble is shorter than a duration for which the destination node is asleep in the sleeping state and the method comprises: at least one operation of a 1-hop neighbor node of the sender node relaying the initial preamble to another 1-hop neighbor node of the sender node, where the relaying operation comprises sending a preamble formed from the preamble sent during a preceding relaying operation, the preamble sent during a first relaying operation being formed from the initial preamble, and continuing said at least one relaying operation until the destination node for the data detects the sent preamble.