Patent ID: 7126473

Claim:
An intrusion detection and remote alarm communication system comprising: an intrusion detecting sensor, said sensor being capable of detecting the entry of an intruder into a space, said sensor communicating with a transmitter, said sensor sending a predetermined signal to said transmitter when an intruder is detected, said sensor in a location proximate to said transmitter, a transmitter, said transmitter transmitting a signal to a receiver, said signal having a first mode and a second mode, said first mode being a prearranged secret sequence of different messages known as the first set, said first mode indicating a normal secure condition, said second mode indicating that said sensor has sent said predetermined signal to said transmitter that an intruder has been detected, said second mode being the alarm mode, a receiver, located at a distance from said transmitter, said receiver having means for receiving said signal from said transmitter, said receiver having access to a second set of said prearranged secret sequence of different messages identical to said first set, said receiver having means for comparing said received sequence with said second set and recognizing that said received sequence corresponds with said second set and responding by indicating a normal secure condition, said receiver recognizing that said received sequence does not correspond with said second set and responding by indicating an alarm condition, said receiver recognizing an interruption in said signal and responding by indicating an alarm condition, said receiver recognizing said second mode and responding by indicating an alarm condition.