Beacon for locating and tracking wireless terminals

• US 20040203566A1
• Filed: 10/24/2002
• Published: 10/14/2004
• Est. Priority Date: 08/30/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Leung, Lauren Kwankit
• Granted Patent: US 6,907,238 B2
• Time in Patent Office: Days
• US Class Current: 455/404.1
• CPC Class Codes: G01S 1/68 Marker, boundary, call-sign, or like beacons transmitting signals not carrying directional information
• CPC Class Codes: G01S 2205/002 for traffic control, mobile tracking, guidance, surveillance or anti-collision
• CPC Class Codes: G01S 2205/006 for emergency situations
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 3/14 Systems for determining direction or deviation from predetermined direction aerial arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00; combinations of different interacting aerial units for giving a desired directional characteristic H01Q21/29; aerials or aerial systems providing at least two radiation patterns H01Q25/00
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

A method and apparatus to facilitate the locating and tracking of a wireless terminal, which may be advantageously used for E-911 service. The terminal may be directed to transmit a beacon for certain events, such as in connection with a 911 call. The beacon has a specific format known by the wireless network, and may be periodically or continuously transmitted. The beacon may be transmitted using various schemes. In a first scheme, the terminal transmits the beacon only when directed to do so by a designated network entity (e.g., the PSAP). In a second scheme, the terminal transmits the beacon in conjunction with the 911 call, and is thereafter directed to terminate the beacon transmission by the designated network entity. The beacon allows the terminal to be accurately located even if it has moved or is physically located in an enclosed or “not-so-obvious” location.

Claims

1. A method of transmitting a beacon used to locate a terminal in a wireless communication network, comprising:

receiving a first command to initiate a call of a particular type;

providing data for a position estimate for the terminal;

processing data for the call and data for the position estimate to provide a first modulated signal;

transmitting the first modulated signal;

receiving a second command to initiate transmission of a beacon;

processing data for the beacon to provide a second modulated signal having included therein the beacon; and

transmitting the second modulated signal.

2. The method of claim 1, wherein the call is an emergency 911 call.

3. The method of claim 1, wherein the second command is received via the wireless communication network.

4. The method of claim 1, wherein the second command is received from a Public Safety Answering Point (PSAP).

5. The method of claim 1, wherein the second command is generated by the terminal, the method further comprising:

receiving a third command to stop transmitting the beacon; and

terminating the transmission of the beacon in response to receiving the third command.

6. The method of claim 1, wherein the beacon is transmitted continuously.

7. The method of claim 1, wherein the beacon is transmitted periodically.

8. The method of claim 1, wherein the beacon is transmitted based on one of a plurality of possible transmission schemes.

9. The method of claim 1, further comprising:

receiving a plurality of signals from a plurality of transmitters; and

processing the plurality of signals to provide the data for the position estimate.

10. The method of claim 9, wherein the plurality of transmitters include at least one GPS satellite.

11. The method of claim 1, wherein the processing of the data for the beacon includes covering data of a particular data pattern with a particular channelization code.

12. The method of claim 11, wherein the particular channelization code is a Walsh code reserved for use for beacon transmission in the wireless communication network.

13. The method of claim 11, wherein the particular data pattern is specified by the second command.

14. The method of claim 1, wherein the second modulated signal is transmitted at a particular power level.

15. The method of claim 14, wherein the particular power level is specified by the second command.

16. A method of controlling transmission of beacons used to locate terminals in a wireless communication network, comprising:

receiving and processing a call of a particular type from a particular terminal;

recovering a position estimate for the terminal based on data received with the call;

sending a command to instruct the terminal to start transmitting a beacon; and

providing the recovered position estimate for the terminal.

17. The method of claim 16, wherein the call is an emergency 911 call.

18. The method of claim 16, wherein the command indicates a particular data pattern to use for the beacon.

19. The method of claim 16, wherein the command indicates a particular channelization code to use for the beacon.

20. The method of claim 16, wherein the command indicates a particular transmit power level to use for the beacon.

21. A terminal in a wireless communication network, comprising:

a transmit (TX) data processor operative to process data for a call of a particular type to provide first processed data;

a modulator coupled to the TX data processor and operative to process the first processed data to provide first modulated data, and to process data for a beacon to provide second modulated data;

a transmitter coupled to the modulator and operative to condition the first modulated data to provide a first modulated signal, and to condition the second modulated data to provide a second modulated signal; and

a controller operative to initiate processing of the data for the call in response to receiving a first command, and to initiate processing of the data for the beacon in response to receiving a second command.

22. The terminal of claim 21, wherein the second command is received via the wireless communication network.

23. The terminal of claim 21, wherein the call is an emergency 911 call.

24. The terminal of claim 21, wherein the controller is further operative to terminate the processing of the data for the beacon in response to receiving a third command.

25. The terminal of claim 21, wherein the modulator is operative to cover the data for the beacon with a particular channelization code.

26. The terminal of claim 25, wherein the particular channelization code is a Walsh code reserved for use for beacon transmission in the wireless communication network.

27. The terminal of claim 21, wherein the transmitter is operative to set power level of the second modulated signal based on the second command.

28. The terminal of claim 21, wherein the beacon is transmitted periodically.

29. The terminal of claim 21, wherein the beacon is transmitted continuously.

30. An apparatus in a wireless communication network, comprising:

means for receiving a first command to initiate a call of a particular type;

means for providing data for a position estimate for the terminal;

means for processing data for the call and data for the position estimate to provide a first modulated signal;

means for transmitting the first modulated signal;

means for receiving a second command to initiate transmission of a beacon;

means for processing data for the beacon to provide a second modulated signal having included therein the beacon; and

means for transmitting the second modulated signal.

31. The apparatus of claim 30, wherein the means for processing the data for the beacon includes means for covering data of a particular data pattern with a particular Walsh code.

32. The apparatus of claim 31, wherein the particular data pattern and the particular Walsh code are specified by the second command.

33. The apparatus of claim 30, further comprising:

means for setting power level of the second modulated signal based on the second command.