Patent ID: 7363488

Claim:
In a security system comprising a plurality of wireless transmitters, each having a unique identification number, at least one wireless receiver module in communication with each of the transmitters, and a control panel connected to the receiver module for processing signals sent from the transmitters to the receiver module, a method of prefiltering the received wireless signals comprising the steps of: a) generating a prefiltering map comprising the steps of: i. for each of the transmitters in the security system, performing an algorithm on the identification number of the transmitter; ii. storing the result of the algorithm in a prefiltering map; b) storing the prefiltering map in the receiver module; c) for each wireless message received by the receiver module from a transmitter, the receiver module performing the steps of: i. extracting from the message the identification number of the transmitter that transmitted the message; ii. performing the algorithm on the extracted identification number; iii. comparing the result against the prefiltering map in the receiver module; iv. forwarding the message to the control panel if the comparison result is true; and v. discarding the message if the comparison result is false; wherein the prefiltering map is not modified as a result of forwarding the message to the control panel if the comparison result is true or discarding the message if the comparison result is false.