Femtocell fingerprinting

• US 9,100,891 B2
• Filed: 01/02/2014
• Issued: 08/04/2015
• Est. Priority Date: 07/17/2013
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Zheng, Dong, Mhetre, Vikram Shantveer, Gupta, Sudip Alexei, Nargundkar, Sagar, Liu, Yuan, Prakasam, Sridhar, Budhwani, Sultan, Sarthavalli Ramesh, Sandeep, Pandit, Abhishek, Rollinger, Odile, Mohajer, Mojan, Majumdar, Soma, Diwan, Aniruddha Subhash
• Primary Examiner(s): DOAN, PHUOC HUU
• Application Number:
  US14/146,315
• Publication Number:
  US 20150024760A1
• Time in Patent Office: 579 Days
• Field of Search: 455/444, 455/410, 455/434, 455/449, 455/422.1
• US Class Current: 1/1
• CPC Class Codes: H04W 36/0061 of neighbour cell information
• CPC Class Codes: H04W 36/0079 in case of hand-off failure or rejection
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

User equipment (UE) includes an architecture for handling femtocell fingerprints. The architecture may, as examples, maintain the validity and reliability of fingerprints and coordinate enhancement to existing fingerprints. The architecture also supports fingerprint creation, updating, and deletion.

Claims

1. A method comprising:

providing a central fingerprint database operable to store a fingerprint for proximity detection, the fingerprint characterizing proximity of a femtocell;

executing a fingerprint manager in communication with the fingerprint database for;

creating the fingerprint, and storing, for the fingerprint, a fingerprint component that characterizes proximity of the femtocell; and

executing a proximity detector in communication with the fingerprint database, and, with the proximity detector;

obtaining an environmental measurement;

analyzing the fingerprint to find that the fingerprint is a matching fingerprint with respect to the environmental measurement; and

initiating a cell search for a specific femtocell that corresponds to the matching fingerprint.

2. The method of claim 1, further comprising:

determining a particular femtocell for enhanced fingerprinting, and in response;

creating multiple fingerprints in the central fingerprint database for that particular femtocell.

3. The method of claim 2, where determining comprises:

determining the particular femtocell responsive to frequency of selection of that particular femtocell.

4. The method of claim 2, where determining comprises:

determining the particular femtocell responsive to recency of selection of that particular femtocell.

5. The method of claim 1, further comprising:

obtaining the fingerprint component from radio resource control measurements of neighboring macrocells.

6. The method of claim 1, further comprising:

obtaining the fingerprint component from positioning system measurements of location.

7. The method of claim 1, further comprising:

obtaining the fingerprint component from wireless network measurements of visible access points.

8. The method of claim 1, where creating the fingerprint comprises:

creating multiple different fingerprints corresponding to multiple different physical approaches to a particular femtocell among the femtocells.

9. The method of claim 1, further comprising:

determining when the fingerprint has triggered more than a threshold number of failed cell searches, and in response;

deleting the fingerprint from the central fingerprint database.

10. The method of claim 1, where creating the fingerprint comprises:

creating the fingerprint responsive to successful connections to the femtocells.

11. The method of claim 1, further comprising:

selectively updating the fingerprint component.

12. The method of claim 1, further comprising:

deleting the fingerprint.

13. A system comprising:

a central fingerprint database operable to store a fingerprint of a femtocell;

a fingerprint manager in communication with the fingerprint database, the fingerprint manager configured to;

create the fingerprint in the fingerprint database, and store, for the fingerprint, a fingerprint component that represents a proximity characteristic of the femtocell; and

a proximity detector in communication with the fingerprint database, the proximity detector configured to;

obtain location information applicable to a device;

compare the fingerprint to the location information to determine whether to trigger a cell search; and

initiate a current attempt to connect the device to the femtocell when the cell search is triggered.

14. The system of claim 13, where:

the proximity detector is further configured to;

increase time between subsequent attempts as remaining power supply energy decreases.

15. The system of claim 13, where:

the proximity detector is further configured to;

determine when the fingerprint has triggered more than a threshold number of failed connection attempts, and in response;

increase a time interval until initiation of a subsequent attempt to connect the device.

16. The system of claim 13, where:

the fingerprint manager is further configured to;

determine a reliability criterion for the fingerprint; and

delete the fingerprint when the reliability criterion fails a reliability threshold.

17. The system of claim 13, where:

the proximity detector is further configured to;

increase time between subsequent attempts when a prior attempt has failed.

18. The system of claim 13, where:

the fingerprint manager is further configured to;

create an additional fingerprint for the femtocell, where the additional fingerprint characterizes a different physical approach to the femtocell.

19. The system of claim 13, where:

the fingerprint component comprises a macrocell identity for a macrocell visible from the femtocell.

20. The system of claim 13, where:

the fingerprint manager is further configured to;

update the fingerprint when an update criterion is met.

21. The system of claim 20, where:

the update criterion comprises an updated frequency configuration of the femtocell, a neighboring cell, or both.

22. The system of claim 20, where:

the update criterion comprises a changed physical cell identity or a changed primary scrambling code.

23. A system comprising:

a non-volatile fingerprint memory;

a fingerprint database;

a fingerprint manager in communication with the fingerprint database, the fingerprint manager configured to;

obtain, after power-up, a fingerprint of a local cell for a restricted subscriber group from the non-volatile fingerprint memory;

store the fingerprint in the fingerprint database, and store, for the fingerprint, a fingerprint component comprising a proximity characteristic of the local cell;

update the fingerprint when an update criterion is met;

determine a reliability criterion for the fingerprint; and

delete the fingerprint when the reliability criterion fails the reliability threshold;

a proximity detector in communication with the fingerprint database, the proximity detector configured to;

obtain an environment characteristic applicable to a device;

compare the fingerprint to the environmental characteristic to determine whether to trigger a cell search; and

initiate an attempt to connect the device to the local cell when the cell search is triggered; and

where the fingerprint manager is operable to obtain the fingerprint component from any set of one or more of;

a radio resource control input operable to convey a macrocell measurement as the fingerprint component to the fingerprint manager;

a positioning system input operable to convey physical location information as the fingerprint component to the fingerprint manager; and

a wireless network input operable to convey wireless access point information as the fingerprint component to the fingerprint manager.

24. The system of claim 23, where:

the proximity detector is further operable to;

perform a phased comparison to the fingerprint, including a coarse match that triggers a subsequent acquisition of additional environment characteristics; and

confirm identity of the local cell by acquiring system information.