Abstract: An apparatus (10, 240, 300) includes a signpost (11, 241-256, 322, 612, 623, 626-628, 652, 661, 682, 686, 703) which transmits signpost signals (24) that are received by a tag (12, 271-275, 301-316, 395-397, 616-618, 641-643, 653, 656-657, 662-664, 679, 708, 711). The tag in turn transmits radio frequency beacon signals (72) which are received by a reader (13, 261, 319, 521-530) The tag can vary the duration of the beacon signals, for example in dependence on whether it is currently receiving a signpost signal. Further, the tag can dynamically vary the transmission rate and/or transmission power of the beacon signals, for example following receipt of a signpost signal. Varying these parameters can facilitate compliance with governmental regulations.

Abstract: An intrusion detection technique involves: emitting a wireless signal within a container; detecting the wireless signal near the container; and responding to detection of a change in a characteristic of the detected wireless signal by transmitting a wireless notification to a location remote from the container. A different technique involves: responding to a determination that a condition representative of unauthorized intrusion is present while the container is stationary by transmitting a wireless notification; and responding to a determination that the container is moving by ignoring whether the condition is present. Yet another technique involves: monitoring whether a door of a container is in a closed position; and emitting a wireless signal indicating whether the container door is in the closed position.

Abstract: An apparatus (10, 240, 300) includes a signpost (11, 241-256, 322, 612, 623, 626-628, 652, 661, 682, 686, 703) which transmits signpost signals (24) to a tag (12, 271-275, 301-316, 395-397, 616-618, 641-643, 653, 656-657, 662-664, 679, 708, 711), which in turn transmits beacon signals (72) to a reader (13, 261, 319, 521-530). One of the signpost and tag is mounted on an item to be tracked. A control system (14, 500) is responsive to the reader, and can cause the signpost to vary the signpost signal in a manner which varies at least one operational characteristic of the tag, such as a transmission rate, a transmission power, a tag identification code, a password, or an encryption code, or which shifts the tag between a normal operational mode and a low power operational mode in which its transmitter is disabled.

Abstract: A device (12) facilitates sealing and tracking of a container (18). The device includes a bolt (166) which extends through openings in a latch mechanism (19) on the container. The bolt also passes through spaced coils (251, 252) of the seal device. The seal device uses one coil to generate a magnetic field, while monitoring the corresponding magnetic field induced in the other coil. Tampering with the bolt affects the magnetic field, which in turn permits the seal device to detect the tampering. The seal device periodically transmits wireless signals (71), which can be remotely received for purposes of tracking the container and monitoring the integrity of the seal.

Abstract: A signpost (11, 241-256, 322, 612, 623, 626-628, 652, 661, 682, 686, 703) transmits low frequency signals to a beacon tag (12, 271-275, 301-316, 395-397, 616-618, 641-643, 653, 656-657, 662-664, 679, 708, 711), which in turns transmits high frequency signals containing a signpost code from a received signpost signal to a reader (13, 261, 319, 521-530). The signpost can be mounted on one mobile device and the beacon tag on another mobile device, in order to determine when those mobile devices are in close proximity. Further, a sensor (32) can be provided to detect the presence of a mobile device, and to cause the signpost to change the signpost code in its transmitted signals.

Abstract: An apparatus (10, 240, 300) includes a signpost (11, 241-256, 322, 612, 623, 626-628, 652, 661, 682, 686, 703) which transmits signpost signals (24) to a tag (12, 271-275, 301-316, 395-397, 616-618, 641-643, 653, 656-657, 662-664, 679, 708, 711), which in turn transmits beacon signals (72) to a reader (13, 261, 319, 521-530). One of the signpost and tag is mounted on an item to be tracked. A control system (14, 500) is responsive to the reader, and can cause the signpost to vary the signpost signal in a manner which varies at least one operational characteristic of the tag, such as a transmission rate, a transmission power, a tag identification code, a password, or an encryption code, or which shifts the tag between a normal operational mode and a low power operational mode in which its transmitter is disabled.

Abstract: An apparatus (10, 240, 300) includes a signpost (11, 241-256, 322, 612, 623, 626-628, 652, 661, 682, 686, 703) which transmits relatively low frequency signpost signals that are fundamentally magnetic in character, a beacon tag (12, 271-275, 301-316, 395-397, 616-618, 641-643, 653, 656-657, 662-664, 679, 708, 711) which receives the signpost signals and transmits radio frequency signals containing a signpost code (42, 93) from a received signpost signal, and a reader (13, 261, 319, 521-530) which receives the radio frequency signals. One of the signpost and tag is stationarily supported, and the other is mounted on a moveable item. Based on the signals received by the reader, the location of the item can determined with a high degree of accuracy.

Abstract: An apparatus (10, 240, 300) includes a signpost (11, 241-256, 322, 612, 623, 626-628, 652, 661, 682, 686, 703) which transmits signpost signals (24) that are received by a tag (12, 271-275, 301-316, 395-397, 616-618, 641643, 653, 656-657, 662-664, 679, 708, 711). The tag in turn transmits radio frequency beacon signals (72) which are received by a reader (13, 261, 319, 521-530) The tag can vary the duration of the beacon signals, for example in dependence on whether it is currently receiving a signpost signal. Further, the tag can dynamically vary the transmission rate and/or transmission power of the beacon signals, for example following receipt of a signpost signal. Varying these parameters can facilitate compliance with governmental regulations.

Abstract: A signpost (11, 241-256, 322, 612, 623, 626-628, 652, 661, 682, 686, 703) transmits low frequency signals to a beacon tag (12, 271-275, 301-316, 395-397, 616-618, 641-643, 653, 656-657, 662-664, 679, 708, 711), which in turns transmits high frequency signals containing a signpost code from a received signpost signal to a reader (13, 261, 319, 521-530). The signpost can be mounted on one mobile device and the beacon tag on another mobile device, in order to determine when those mobile devices are in close proximity. Further, a sensor (32) can be provided to detect the presence of a mobile device, and to cause the signpost to change the signpost code in its transmitted signals.