Method to control the update frequency of a positioning device by a mobile terminal

• US 7,209,753 B2
• Filed: 12/03/2004
• Issued: 04/24/2007
• Est. Priority Date: 09/07/2000
• Status: Expired due to Fees

• Current Assignee: IDTP Holdings Incorporated (InterDigital, Inc.)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Raith, Alex Krister
• Primary Examiner(s): Nguyen; Lee
• Application Number:
  US11/004,211
• Publication Number:
  US 20050101333A1
• Time in Patent Office: 872 Days
• Field of Search: 455/456.1, 455/434, 455/343, 455/574, 455/515, 455/41.2, 455/552.1, 342/357.01, 342/357.06, 342/357.08, 342/357.1, 342/357.12, 342/104, 342/107, 342/109, 342/457
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 2205/008 using a mobile telephone network

Abstract

A mobile radiocommunications terminal contains or is operatively connected to a position estimator, such as a GPS receiver. The mobile terminal stores at least one reference position. The mobile terminal updates its position at a frequency that is a function of its distance from the reference position, or as a function of the rate of change of its distance from the reference position.

Claims

1. A method of initiating a search for a control channel in a communications network by a mobile terminal, said method comprising:

storing at least one reference position indicative of a central point of said communications network in said mobile terminal;

determining the current position of said mobile terminal;

computing the distance of said current position of said mobile terminal from said reference position; and

initiating a search for a channel based on said distance between said mobile terminal and said communication network.

2. The method of claim 1, including establishing communication between said and said mobile terminal and said communication network.

3. The method of claim 2 wherein establishing communications between said mobile terminal and said communications network comprises establishing communication with a private radiocommunication system.

4. The method of claim 3 wherein establishing communication with a private radiocommunication system comprises establishing communication with said private radiocommunication system via a short-range air interfere.

5. The method of claim 4 wherein establishing communication with said private radiocommunication system via a short-range air interfere comprises establishing communication with said private radiocommunication system via a Bluetooth interface.

6. The method of claim 1, wherein determining the current position of said mobile terminal comprises receiving signals from navigation satellites and calculating said current position from said signals received from said navigation satellites.

7. The method of claim 1, wherein determining said current position of said mobile terminal is repeated at intervals dependant on said distance of said current position of said mobile terminal from said reference position.

8. The method of claim 1, further comprising determining the rate of change in said position of said mobile terminal relative to said reference position.

9. The method of claim 8, wherein determining said current position of said mobile terminal is repeated at intervals dependant on said rate of change of distance of said mobile terminal from said reference position.

10. A mobile terminal comprising:

a transceiver transmitting and receiving signals over a wireless channel;

memory storing at least one reference position indicative of a central point of a communications network;

a position estimator to determine a current position of said mobile terminal; and

control logic including a processor to calculate the distance of said mobile terminal from said reference position based on said current position of said mobile terminal and to initiate a search for a channel based on said calculated distance.

11. The mobile terminal of claim 10, wherein said position estimator comprises a receiver adapted to receive signals from navigation satellites and to calculate said current position from said received signals.

12. The mobile terminal of claim 10, wherein said control logic further calculates the rate of change of said current position relative to said reference position.

13. The mobile terminal of claim 12, wherein said control logic updates said current position at a frequency dependant on said rate of change of said current position relative to said reference position.

14. The mobile terminal of claim 10 wherein said mobile terminal further comprises a Bluetooth interface.

15. A method of controlling the initiation of a search by a mobile terminal for a channel associated with a radiocommunication system comprising:

repeatedly determining the location of the mobile terminal with respect to a central point associated with the radio communication system; and

initiating a search for a channel associated with said radio communication system if the computed distance between the mobile terminal and the central point is less than a predetermined distance.

16. A method of initiating a search for a control channel in a communications network by a mobile terminal, said method comprising:

storing a plurality of reference positions defining the boundary of said communications network in said mobile terminal;

determining the current position of said mobile terminal;

comparing said current position of said mobile terminal to said boundary; and

initiating a search for a channel if said mobile terminal position is within said boundary.

17. A mobile terminal comprising:

a transceiver transmitting and receiving signals over a wireless channel;

memory storing a plurality of reference positions defining the boundary of a communications network;

a position estimator to determine a current position of said mobile terminal; and

control logic including a processor to compare the current position of said mobile terminal to said reference positions and to initiate a search for a channel if said current position is within said boundary.