SELF-POSITIONING ACCESS POINTS

• US 20090310593A1
• Filed: 06/17/2008
• Published: 12/17/2009
• Est. Priority Date: 06/17/2008
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sheynblat, Leonid, Heshmati, Ardalan
• Application Number:
  US12/140,634
• Publication Number:
  US 20090310593A1
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04J 3/0638 Clock or time synchronisation among nodes; Internode synchronisation synchronization for ring networks H04L12/422; data switching networks with synchronous transmission H04L12/43
• CPC Class Codes: H04J 3/0644 External master-clock
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A system, method and apparatus are provided which relate to calibrating a wireless access point so as to allow proper synchronization of mobile wireless devices connecting to the wireless access point. A closed-loop filter is used to more accurately synchronize times and to more accurately determine the location of the access point for purposes of determining the position of a mobile station.

Claims

1. An access point for a wireless network comprising:

a clock configured to generate clock timing signals;

a closed-loop filter coupled to said clock, said filter configured to cause synchronization of said clock timing signals with timing signals received from a network connected to the Internet; and

a processor configured to calibrate said clock.

2. An access point as recited in claim 1 wherein said filter is further operable to output timing offsets of said clock timing signals from timing signals received from a network connected to the Internet.

3. An access point as recited in claim 1 wherein the filter is a Kalman filter.

4. An access point as recited in claim 1 wherein said network is a Wide Area Network.

5. An access point as recited in claim 1 wherein said timing signal received from said network connected to the Internet are generated by a server implementing the Network Time Protocol.

6. An access point as recited in claim 1 wherein said processor is capable of calibrating said clock through use of hardware.

7. An access point as recited in claim 1 wherein said processor is capable of calibrating said clock through use of software.

8. An access point as recited in claim 1 wherein said timing signals received from said network connected to the Internet are synchronized with timing signals generated by a satellite positioning system.

9. An access point as recited in claim 8 wherein said satellite positioning system consists of GPS, Galileo, GLONASS, NAVSTAR, GNSS or a combination thereof.

10. A method of synchronizing a wireless network access point comprising:

receiving a timing signal from a satellite positioning system time source;

Kalman filtering said timing signal; and

calibrating a wireless access point clock using output from said Kalman filtering.

11. A method as recited in claim 10 wherein said timing signal is generated by a source implementing the Network Time Protocol.

12. A computer program product stored on a tangible medium that stores instructions which when executed by a processor causes Kalman filtering of data representative of a timing signal and determines calibration data for a wireless access point frequency source.

13. A computer program as recited in claim 12 wherein said timing signal is sourced from a satellite positioning system.

14. A computer program as recited in claim 13 wherein said satellite positioning system consists of GPS, Galileo, GLONASS, NAVSTAR, GNSS or a combination thereof.

15. A system for obtaining service through a secondary network comprising:

a Wi-Fi access point for a network coupled to the Internet, said access point including a clock configured to generate clock timing signals and a filter having a feedback loop coupled to said clock, said filter configured to cause synchronization of said clock timing signals with timing signals received from said secondary network; and

a processor configured to calibrate said clock and forwarding voice and data information to and from said secondary network.

16. A system as recited in claim 15 wherein said secondary network is connected to the Internet.

17. A system as recited in claim 15 wherein said processor is capable of forwarding voice and data information to a mobile station having a wireless transceiver.

18. A system as recited in claim 17 which further includes a server for calculating information consisting of billing, determining access to features, mobile station positioning, navigation directions or a combination thereof, said server being capable of receiving requests from a mobile station consisting of mobile station positioning requests, mobile station navigation requests and a combination thereof.

19. A system as recited in claim 15 wherein said filter is a Kalman filter.

20. A system as recited in claim 15 wherein said network is a Wide Area Network.

21. A system as recited in claim 18 wherein said server is accessible through the Internet.

22. An access point means for providing wireless access to a network comprising:

a clock operable to generate clock timing signals;

recursive filter means coupled to said clock, said filter means being operable to cause synchronization of said clock timing signals with timing signals received from a network connected to the Internet and

a processor being capable of calibrating said clock.