Abstract: A method of locating a mobile telephone includes steps of receiving, transmitting, increasing and determining. In the receiving step, a first base station receives a call from a mobile telephone, the call including a dialed number and a TDMA signal. In the transmitting step, the base station transmits a control message to the mobile telephone when the dialed number meets a predetermined criterion, such as being 911. The control message instructs the mobile telephone to transmit the TDMA signal at a maximum power. In the increasing step, the mobile telephone increases the TDMA signal to maximum power in response to the control message. Then in the determining step, location information for the mobile telephone is determined based on at least one characteristic of the TDMA signal received at at least one of the first base station and other base stations.
Type:
Application
Filed:
May 24, 2002
Publication date:
September 26, 2002
Applicant:
AT&T Wireless Sevices, Inc.
Inventors:
Nelson Ray Sollenberger, Jack Harriman Winters
Abstract: A remote unit for a personal wireless area network includes a receiver, an AC power supply, a battery-backup power supply and a controller. The battery-backup becomes operative when the AC power supply fails and supplied power to the receiver. The controller detects when the AC power supply fails and controls the receiver and the battery-backup power supply by invoking a sleep mode of operation. The sleep mode of operation is periodically interrupted by the controller controlling the receiver and the battery-backup power supply to enter a standby mode of operation in which the receiver scans for a CONNECT message from a base station indicating an incoming call. The controller coordinates the sleep mode and the standby mode of operations based on a frame count that is generated from an identification number of the remote unit.