Method and apparatus for enhanced 911 location using power control in a wireless system

A method of locating a mobile telephone, the method comprising:

• receiving at a base station a signal from a mobile telephone;
• invoking a location function in response to the signal;
• determining whether the mobile telephone should increase power for location determination;
• transmitting from the base station to the mobile telephone a control message instructing the mobile telephone to transmit a signal at an increased power level based on the determining;
• receiving at least one of a plurality of base stations the signal transmitted at the increased power level;
• and
• calculating a location of the mobile telephone based on the signal received at least one of the plurality of base stations.

An apparatus for locating a mobile telephone, the apparatus comprising:

• a plurality of base stations communicating signals with a mobile telephone;
• a mobile switching center, coupled with the plurality of base stations, the mobile switching center a) receiving from one of the plurality of base stations a call that includes a dialed number of the mobile telephone, b) determining whether the dialed number invokes a location function, and c) sending an instruction to the mobile telephone via one of the plurality of base stations to increase transmission power when the location function is invoked;
• and
• a location processor, coupled with the plurality of base stations and the mobile switching center, the location processor determining the location of the mobile telephone based on the signals received from the mobile telephone via at least one of the plurality of base stations at the increased power level.

A method of locating a mobile telephone, the method comprising:

• receiving at a base station a call from a mobile telephone, the call including a dialed number and a signal;
• invoking a location function in one of a mobile switching center and a location system;
• transmitting from the base station to the mobile telephone a control message instructing the mobile telephone to transmit the signal at a maximum power;
• increasing the signal to maximum power in response to the control message;
• and
• determining location information for the mobile telephone based on at least one characteristic of the signal received at the base station.

A method comprising:

• a mobile telephone determining to transmit at a higher-than-normal operating power level according to a number to dial;
• the mobile telephone placing a call to the number to dial and transmitting at the higher power level;
• the mobile telephone receiving a signal in response to successful location determination of the mobile phone;
• the mobile telephone decreasing transmission power in response to receiving the signal.