Patent ID: 7633391

Claim:
A surveillance system, comprising: an unattended sensor having a detector that generates an electrical signal in response to a physical stimulus proximate to the sensor; a signal processor adapted to receive the electrical signal from the detector and operable to generate event messages based on the electrical signal; a transceiver adapted to receive the event messages and operable to send the event messages over a wireless radio link; a channel access mechanism operable to negotiate access to the radio link in accordance with an access protocol, where the channel access mechanism receives messages from other nodes in the system indicating that a given node is about to receive a transmission and delays any transmissions from the sensor to the given node; an encryption module interposed between the signal processor and the channel access mechanism and operable to encrypt messages received from the signal processor; and a radio device having a transceiver operable to send and receive voice data over the radio link; and a channel access mechanism operable to negotiate access to the radio link in accordance with the same access protocol.