Patent ID: 6330437
Filing Date: 2001-12-11
Classification: H04M,H04W

Abstract:
A range-limit verification method in a wireless telecommunications system comprising at least two parts communicating by radio channel inside a coverage area, the method comprising:a. reading an electric field level received by the second part and transmitted by the first partb. generating a range-limit signal when an electric field level received by the second part falls below a predetermined detection threshold;c. triggering a presence verification step in response to said range-limit signal for verifying presence of said first part inside the coverage area, said presence verification comprising:i. enabling said second part to transmit a request message requesting confirmation of presence of said first part; andii. enabling said first part to respond to said request message by transmitting a presence-confirmation signal for receipt by said second part for verifying said presence,wherein said communicating by radio channel is uninterrupted when said parts are maintained in an off-hook condition while one of said parts is moved from a range-limit detection are to a periphery of said coverage area thereby increasing a range of use.