Patent ID: 6981157

Claim:
A method for use by a device operating on a network over which multiple devices belonging to a defined set communicate with each other by transmitting and receiving messages, the method comprising: transmitting the messages at a frequency that hops from one frequency to another over time in accordance with a predictable pseudo-random hopping sequence that determines each frequency in the hopping sequence from a particular identifier associated with one of the devices and a universal time parameter; characterized in that: each frequency in the hopping sequence is determined from a known function of the particular identifier, the universal time parameter, and a seed that is changed over time and that further randomizes the hopping sequence from the predictable pseudo-random hopping sequence that which would otherwise be determined from the particular identifier and the universal time parameter alone, whereby a pattern of changing transmit frequencies that is detected in messages received by a device outside the defined set is impeded from being associated with the particular identifier associated with one of the devices within the set.