Method and apparatus for providing reserve power in a cellular telephone

• US 6,408,196 B2
• Filed: 08/02/2001
• Issued: 06/18/2002
• Est. Priority Date: 07/02/1998
• Status: Expired due to Term

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Inventors: Wolf, Thomas George, Sheynblat, Leonid
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): PEREZ GUTIERREZ, RAFAEL
• Application Number:
  US09/921,971
• Publication Number:
  US 20020016189A1
• Time in Patent Office: 320 Days
• Field of Search: 455/574, 455/575, 455/521, 455/404, 455/456, 455/414, 342/357.1
• US Class Current: 455/574
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/09 providing processing capability normally carried out by the receiver
• CPC Class Codes: G01S 19/17 Emergency applications
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 2205/006 for emergency situations
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/145 Using a supplementary range measurement, e.g. based on pseudo-range measurements
• CPC Class Codes: H04W 52/0277 according to available power supply, e.g. switching off when a low battery condition is detected
• CPC Class Codes: H04W 52/0296 switching to a backup power supply
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Reserve power is provided in a portable cellular transceiver comprising a Global Positioning System (GPS) receiver by monitoring a power level of a battery of the portable cellular transceiver using a power detection circuit. A comparator circuit determines whether the power level of the battery is greater than a predetermined threshold. Based on the available power level, a power control circuit automatically places the transceiver into at least one low power mode when the power level reaches a corresponding threshold level. The low power mode selectively powers down circuitry of the portable cellular transceiver. The corresponding threshold level reserves power for an emergency telephone call. Power is provided to the circuitry of the portable cellular transceiver when the available power level is greater than the predetermined threshold. The reserve power provides power for the activation of the portable cellular transceiver, establishment of a call between the portable cellular transceiver and a cellular base station, transfer of GPS satellite acquisition aiding information to the portable cellular transceiver, receipt of GPS satellite information, communication of GPS satellite information to the cellular base station, and determination of a position of the portable cellular transceiver. The emergency telephone call may be a single button enhanced 911 call.

Claims

1. A method for providing reserve power in a portable cellular transceiver comprising a Global Positioning System (GPS) receiver, the method comprising:

monitoring a power level of a battery of the portable cellular transceiver; and

automatically placing the portable cellular transceiver into at least one low power mode when the power level reaches at least one threshold level, wherein the at least one threshold level reserves power for at least one emergency telephone call, wherein the at least one emergency telephone call is an enhanced 911 call, wherein the reserve power allows for;

activation of the portable cellular transceiver;

establishment of a call between the portable cellular transceiver and a cellular base station;

transfer of GPS satellite acquisition aiding information to the portable cellular transceiver;

receipt of GPS signals; and

communication of GPS satellite information to the cellular base station.

2. A method for providing reserve power in a portable cellular transceiver comprising a Global Positioning System (GPS) receiver, the method comprising:

monitoring a power level of a battery of the portable cellular transceiver; and

automatically placing the portable cellular transceiver into at least one low power mode when the power level reaches at least one threshold level, wherein the at least one threshold level reserves power for at least one emergency telephone call, wherein the automatically placing of the portable cellular transceiver into at least one low power mode comprises selectively powering down circuitry of the portable cellular transceiver.

3. A method as in claim 2 wherein said at least one threshold level also reserves power to perform a position location function.

4. A method as in claim 3 wherein said position location function comprises determining a time associated with a signal between said portable cellular transceiver and a cellular basestation.

5. A method as in claim 3 wherein said position location function comprises receiving Global Positioning System (GPS) signals.

6. A method as in claim 3 wherein said emergency telephone call comprises an enhanced 911 call.