Abstract: A method for providing security and maintenance of a group of devices using a group of tags. Each of the tags is attached to a device and includes a radio frequency transceiver for intercommunicating using ultra-wide band signals. Using the intercommunication, distance between two of the tags is determined and an alarm is triggered when the distance is greater than a threshold distance. The distance is preferably determined by measuring a round trip delay time between the transmission of a transmitted unicast signal to the other tag and reception of a unicast response signal in response to the transmitted signal. A configuration mechanism is typically used for configuring the group and removed upon completing the configuration, and the tags maintain the group and provide security by the intercommunication between the tags. The tags are preferably synchronized to transmit and receive solely during a previously determined periodic sequence of time intervals.

Abstract: A method for providing security and maintenance of a group of devices using a group of tags. Each of the tags is attached to a device and includes a radio frequency transceiver for intercommunicating using ultra-wide band signals. Using the intercommunication, distance between two of the tags is determined and an alarm is triggered when the distance is greater than a threshold distance. The distance is preferably determined by measuring a round trip delay time between the transmission of a transmitted unicast signal to the other tag and reception of a unicast response signal in response to the transmitted signal. A configuration mechanism is typically used for configuring the group and removed upon completing the configuration, and the tags maintain the group and provide security by the intercommunication between the tags. The tags are preferably synchronized to transmit and receive solely during a previously determined periodic sequence of time intervals.

Abstract: A method of providing security and maintenance of a group of devices using a group of tags. Each of the tags is attached to a device and includes a radio frequency transceiver for intercommunicating using ultra-wide band signals. Using the intercommunication, distance between two of the tags is determined and an alarm is triggered when the distance is greater than a previously defined threshold distance. The distance is preferably determined by measuring a round trip delay time between the transmission of a transmitted signal to the other tag and reception of a response signal in response to the transmitted signal from the other tag. The distance is preferably determined by measuring a time delay between transmitting a unicast ultra-wide band message and receiving a unicast response message. The intercommunication preferably uses ultra-wide band signals which relay information regarding completeness of the group between the tags of the group.

Abstract: The present invention relates to a method and system (10) for distance determination of RF tags (4) and its applications, based on measuring the round trip delay, avoiding deterministic collisions between a plurality of wide band response signals transmitted by the tags (4) by adding a pseudo-random time delay to the wide band response signal, and iteratively reducing the collision probability between plurality of wide band response signals.