Location system for bluetooth enabled devices

• US 7,848,704 B2
• Filed: 03/04/2005
• Issued: 12/07/2010
• Est. Priority Date: 03/04/2005
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Smith, Sherry
• Primary Examiner(s): NGUYEN, TUAN HOANG
• Application Number:
  US11/072,150
• Publication Number:
  US 20060199534A1
• Time in Patent Office: 2,104 Days
• Field of Search: 455/41.2, 455/574, 455/41.1, 340/539, 340/573, 340/573.4, 340/328, 340/568.1, 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 BT enabled devices is described. A network of BT 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 Bluetooth device, comprising:

attaching a parent device to a kid device via a manual selection on the parent device or the kid device;

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

leaving the connected state and entering a search mode when the signal of from the parent device falls below the specified threshold, wherein, after leaving the connected state, the kid device is discoverable and connectable,

wherein neither the kid device nor the parent device is deactivated if the parent device and the kid device are no longer in communication range;

re-entering the connected state and returning to the power saving mode when the parent device signal is reacquired;

discovering kid devices in t-he proximity of the parent device;

listing discovered kid devices in a user interface of the parent device;

manually selecting a kid device from the listing of discovered kid devices;

paging the selected kid device; and

if the paging is successfully, transitioning into the connected state.

2. The method of claim 1 wherein the kid device and the parent device comprise a first portable, handheld device and a second portable, handheld device, wherein the first portable, handheld device and the second portable handheld device are Bluetooth-enabled.

3. The method of claim 1, wherein, in the connected state, the kid device can only talk to the parent device.

4. The method of claim 1, comprising:

detaching the parent device from the kid device when the kid device is in the proximity of the parent device.

5. The method of claim 1, comprising:

wirelessly locating the kid device that leaves the connected state by a wireless device other than the parent device.

6. The method of claim 1, comprising:

wirelessly locating the kid device that leaves the connected state by a wireless device other than the parent device, wherein the connected state is a wireless protocol connected state.

7. The method of claim 1 wherein the parent device is a cellular phone.

8. The method of claim 1, comprising:

attaching the kid device to the parent device.

9. The method of claim 1, comprising:

issuing an alarm if an RSSI limit has been traversed or if a response is not received.

10. The method of claim 1, comprising:

entering the search mode when the kid device is lost.

11. The method of claim 1, comprising:

returning to the power saving mode when the received signal is reacquired.

12. The method of claim 1, wherein, in the connected state, the kid device and the parent device negotiate on a sleep time for a hold mode.

13. The method of claim 1, wherein the parent device comprises a Bluetooth-enabled phone.

14. The method of claim 13, wherein the kid 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 Bluetooth device, comprising:

a parent device; and

a kid device, wherein the parent device is attached to the kid device via a manual selection on the parent device or the kid device, wherein, the kid device, after entering a connected state, enters and maintains a power saving mode as long as a received signal from the parent device is above a specified threshold, wherein, in the connected state, the kid device is non-discoverable and non-connectable to other devices other than the parent device, wherein the kid device leaves the connected state when the signal from the parent device falls below the specified threshold, wherein, after leaving the connected state, the kid device is discoverable and connectable, wherein neither the kid device nor the parent device is deactivated if the parent device and the kid device are no longer in communication range, wherein the kid device re-enters the connected state and returns to the power saving mode once the parent device signal is reacquired, wherein the parent device is configured to discover kid devices and to list discovered kid devices in a user interface of the parent device, wherein the parent device is configured to facilitate a manual selection of at least one kid device from the listing of the discovered kid devices, and wherein the parent device is configured to page the selected kid device and, if the paging is successful, is configured to transition into the connected state.

16. The system of claim 15 wherein the kid device is wirelessly attached to a parent device.

17. The system of claim 15 wherein the the parent device issues an alarm if an RSSI threshold has been traversed or the kid device does not respond.

18. The system of claim 15 wherein, when the kid device is in a lost state, the kid device adopts a variable duty cycle for active radio transmission.

19. The system of claim 18 wherein the variable duty cycle causes the kid 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 of claim 15, wherein the kid device comprises an integrated circuit that includes an application layer.

21. The system of claim 20, wherein the integrated circuit is connected to a Bluetooth radio.

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

23. The system of claim 20, wherein the application layer enters a Bluetooth inquiry mode state when a measured RSSI falls below a threshold.

24. The system of claim 20, wherein the integrated circuit has a unique hardware ID.

25. The system of claim 15 wherein, in the connected state, the kid device and the parent device negotiate on a sleep time.

26. The system of claim 15 wherein the parent device or the kid device comprises a Bluetooth-enabled phone.

27. The method of claim 15, wherein detachment between the parent device and the kid device occurs in proximity of the parent device.