Patent ID: 7500105

Claim:
A method of transmitting a message from a security device to a receiving device comprising the steps of: a. forming a two-part data message comprising a first message part and a second message part, i. the first message part comprising 1. a preamble portion, 2. an identification number portion that uniquely identifies the security device, 3. a status portion that comprises status data indicative of the status of the security device, and 4. a CRC portion that contains CRC data based on a CRC function performed on the identification number portion and the status portion, and ii. the second message part comprising 1. a first redundant status portion that comprises the status data from the first message part, and 2. a second redundant status portion that comprises the status data from the first message part, wherein the second redundant status portion is the logical inverse of the first redundant status portion of the second message part; b. encoding the first message part in a first encoding format; c. encoding the second message part in a second encoding format different from the first encoding format; d. modulating a carrier signal with the encoded first message part and the encoded second message part; and e. transmitting the modulated carrier signal.