Location system for Bluetooth® enabled devices

• US 8,023,895 B2
• Filed: 12/07/2010
• Issued: 09/20/2011
• Est. Priority Date: 03/04/2005
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Smith, Sherry
• Primary Examiner(s): Nguyen; Tuan H
• Application Number:
  US12/962,200
• Publication Number:
  US 20110076949A1
• Time in Patent Office: 287 Days
• Field of Search: 455/41.1, 455/41.2, 455/13.4, 455/127.5, 455/522, 455/574, 340/539, 340/568.1, 340/573.4, 340/988
• US Class Current: 455/41.2
• CPC Class Codes: G08B 21/023 Power management, e.g. system sleep and wake up provisions
• CPC Class Codes: G08B 21/0238 adding new units to the system
• CPC Class Codes: G08B 21/0247 System arrangements wherein the alarm criteria uses signal strength
• CPC Class Codes: G08B 21/0272 System arrangements wherein the object is to detect exact location of child or item using triangulation other than GPS
• CPC Class Codes: G08B 21/0277 Communication between units on a local network, e.g. Bluetooth, piconet, zigbee, Wireless Personal Area Networks [WPAN]

Abstract

A method, apparatus, and system for tracking and locating Bluetooth enabled devices is described. A network of Bluetooth sniffers can be used to rapidly locate lost devices and their owners. Wearable child devices maintain low power contact with parent devices until such time as a signal limit is reached, at which point the parent devices alarm. An optional network of fixed sniffing devices can be used to coordinate a search for lost child devices once an alert is issued to the system.

Claims

1. A method of tracking a wireless communication device, comprising:

attaching a first wireless communication device to a second wireless communication device;

after entering a connected state, entering and maintaining a power saving mode as long as a received signal from the first wireless communication device is above a specified threshold, wherein, in the connected state, the second wireless communication device is non-discoverable and non-connectable to other wireless communication devices other than the first wireless communication device;

leaving the connected state and entering a search mode when the signal of from the first wireless communication device falls below the specified threshold, wherein, after leaving the connected state, the second wireless communication device is discoverable and connectable, wherein neither the second wireless communication device nor the first wireless communication device is deactivated if the first wireless communication device and the second wireless communication device are no longer in communication range; and

re-entering the connected state and returning to the power saving mode when the first wireless communication device signal is reacquired.

2. The method according to claim 1, wherein the first wireless communication device comprises a first portable, handheld device, and wherein the second wireless communication device comprises a portable, handheld device.

3. The method according to 1, wherein, in the connected state, the second wireless communication device only communicates with the first wireless communication device.

4. The method according to 1, comprising detaching the first wireless communication device from the second wireless communication device when the second wireless communication device is in the proximity of the first wireless communication device.

5. The method according to 1, comprising wirelessly locating the second wireless communication device that leaves the connected state by a wireless communication device other than the first wireless communication device.

6. The method according to 1, comprising wirelessly locating the second wireless communication device that leaves the connected state by a wireless communication device other than the first wireless communication device, wherein the connected state is a wireless communication connected state.

7. The method according to 1, wherein the first wireless communication device is a cellular device.

8. The method according to 1, comprising attaching the second wireless communication device to the first wireless communication device.

9. The method according to 1, comprising issuing an alarm if an RSSI limit has been traversed or if a response is not received.

10. The method according to 1, comprising entering the search mode when the second wireless communication device is lost.

11. The method according to 1, comprising returning to the power saving mode when the received signal is reacquired.

12. The method according to 1, wherein, in the connected state, the second wireless communication device and the first wireless communication device negotiate on a sleep time for a hold mode.

13. The method according to 1, wherein the first wireless communication device comprises a Bluetooth-enabled phone.

14. The method according to 13, wherein the second wireless communication device comprises one or more of the following:

a wearable device, a wrist band, a faux watch face, an ankle bracelet, a fob, and a necklace.

15. A system for tracking a wireless communication device, comprising:

a first wireless communication device; and

a second wireless communication device,

wherein the first wireless communication device is attached to the second wireless communication device,

wherein, the second wireless communication device, after entering a connected state, enters and maintains a power saving mode as long as a received signal from the first wireless communication device is above a specified threshold,

wherein, in the connected state, the second wireless communication device is nondiscoverable and non-connectable to other devices other than the first wireless communication device,

wherein the second wireless communication device leaves the connected state when the signal from the first wireless communication device falls below the specified threshold,

wherein, after leaving the connected state, the second wireless communication device is discoverable and connectable, wherein neither the second wireless communication device nor the first wireless communication device is deactivated if the first wireless communication device and the second wireless communication device are no longer in communication range, and

wherein the second wireless communication device re-enters the connected state and returns to the power saving mode once the first wireless communication device signal is reacquired.

16. The system according to 15, wherein the second wireless communication device is wirelessly attached to a first wireless communication device.

17. The system according to 15, wherein the first wireless communication device issues an alarm if an RSSI threshold has been traversed or the second wireless communication device does not respond.

18. The system according to 15, wherein, when the second wireless communication device is in a lost state, the second wireless communication device adopts a variable duty cycle for active radio transmission.

19. The system according to 18, wherein the variable duty cycle causes the second wireless communication device to actively transmit more frequently in an initial period of the lost state and to actively transmit less frequently in a later period of the lost state.

20. The system according to 15, wherein the second wireless communication device comprises an integrated circuit that includes an application layer.

21. The system according to 20, wherein the integrated circuit is connected to a radio.

22. The system according to 20, wherein the application layer returns to the power saving mode when a measured RSSI exceeds a threshold.

23. The system according to 20, wherein the application layer enters an inquiry mode state when a measured RSSI falls below a threshold.

24. The system according to 20, wherein the integrated circuit has a unique hardware ID.

25. The system according to 15, wherein, in the connected state, the second wireless communication device and the first wireless communication device negotiate on a sleep time.

26. The system according to 15, wherein the first wireless communication device or the second wireless communication device comprises one or more of the following:

a Bluetooth-enabled phone and a cellular device.

27. The method according to 15, wherein detachment between the first wireless communication device and the second wireless communication device occurs in proximity of the first wireless communication device.