Location system and communication
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Accused Products
Abstract
A location system comprises a plurality of transponders whose locations are detectable by a base system. The base system interrogates (51-55) the transponders one at a time in accordance with a schedule of consecutive time slots. In response to a priority request received (53) from one of the transponders, the base system interrupts the schedule and interrogates substantially immediately (56,57,55) the signalling transponder so as to determine its location with minimal latency.
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Citations
51 Claims
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1-18. -18. (canceled)
- 19. A location system comprising a plurality of devices, each of whose locations is detectable, and a base system for detecting and registering the locations of the devices, the base system being arranged to interrogate the locations of the devices one at a time in a sequence of time slots so that the location of each device is repeatedly interrogated and to interrogate the location of any one of at least some of the devices substantially immediately in response to a radio signal from that same device, each of the devices comprising a transponder arranged to transmit an ultrasonic signal in response to receipt of a polling signal from the base system.
- 26. A location system comprising a plurality of devices, each of whose locations is detectable, and a base system for detecting and registering the locations of the devices, the base system being arranged to interrogate the locations of the devices one at a time in a sequence of time slots so that the location of each device is repeatedly interrogated and to interrogate the location of any one of at least some of the devices substantially immediately in response to a signal from that same device, the sequence of time slots being delayed by a time slot following the or each substantially immediate interrogation.
- 37. A location system comprising a plurality of devices, each of whose locations is detectable, and a base system for detecting and registering the locations of the devices, the base system being arranged to interrogate the locations of the devices one at a time in a sequence of time slots so that the location of each device is repeatedly interrogated and to interrogate the location of any one of at least some of the devices substantially immediately in response to a signal from that same device, the or each substantially immediate interrogation replacing interrogation of another of the devices which would have been interrogated in the absence of the signal from that same device.
- 48. An asynchronous time-division multiplex communication system comprising a scheduler for scheduling a plurality of messages for transmission and for transmitting substantially immediately a priority message in response to a request generated externally of the communication system.
Specification