Femto cell signaling gating

• US 8,812,049 B2
• Filed: 11/26/2013
• Issued: 08/19/2014
• Est. Priority Date: 05/07/2008
• Status: Active Grant

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Brisebois, Arthur Richard, Huber, Kurt Donald
• Primary Examiner(s): Magloire, Vladimir
• Application Number:
  US14/090,802
• Publication Number:
  US 20140080499A1
• Time in Patent Office: 266 Days
• US Class Current: 455/522
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0078 Timing of allocation
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

Signaling in a femto cell access point is managed. A pilot signal power profile, or pilot signal gating, determines transmitted a time-dependent pilot signal power. The power profile displays a duty cycle well below 100% and a power depth, which is the amplitude between maximum and minimum pilot signal power, determined partially upon radio link conditions. The time-dependent power profile can be established through a schedule based at least in part on attachment data or subscriber input; machine-learning method facilitate inferring the schedule. Pilot signal gating profile can be reused in a femto cell deployment to broaden femto cell identification and thus facilitate macro-to-femto handover. Activating/deactivating pilot signal in a femto cell in the scheduled and synchronized manner provided herein leads to macro-femto interference mitigation and mobility improvement(s), and improved battery life of wireless devices that operate in a wireless environment that includes femto cells.

Claims

1. A femtocell device, comprising:

a processor; and

a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising;

determining a duty cycle schedule for a pilot signal of the femtocell device based on a history of attachment events between a macro cell device and the femtocell device;

determining a threshold slope of a change in power over time for the pilot signal, wherein a first rate of change associated with the threshold slope satisfies a defined slope function that mitigates an induced interference condition in a wireless environment in which the femtocell device operates; and

changing a power of the pilot signal over time at a second rate of change that is not greater than the first rate of change, wherein the changing the power is in accordance with the duty cycle schedule.

2. The femtocell device of claim 1, wherein the determining the duty cycle schedule comprises determining an attachment pattern based on the history of attachment events.

3. The femtocell device of claim 1, wherein the operations further comprise identifying an attachment event associated with another femtocell device.

4. The femtocell device of claim 3, wherein the operations further comprise determining a reuse interval that relates to an interval between a first time associated with the attachment event and a second time associated with a second attachment event associated with the femtocell device.

5. The femtocell device of claim 4, wherein the determining the duty cycle schedule comprises determining the duty cycle schedule based on the reuse interval.

6. The femtocell device of claim 1, wherein the operations further comprise facilitating copying the duty cycle schedule to a storage device associated with another femtocell device.

7. The femtocell device of claim 6, wherein the operations further comprise constructing a reuse plan to reuse the duty cycle schedule for the other femtocell device based on an identifier that is common to the femtocell device and the other femtocell device.

8. A non-transitory computer readable storage device comprising executable instructions that, in response to execution, cause a system comprising a processor to perform operations, comprising:

constructing a duty cycle schedule for a pilot signal of the femtocell device based on based on a history of attachment events between a macro cell device and the femtocell device;

identifying a maximum rate of change in power over time for the pilot signal, wherein the maximum rate of change satisfies a defined slope function defined to mitigate an induced interference condition in a wireless environment in which the femtocell device operates; and

updating a power of the pilot signal over time at a second rate of change that is not greater than the first rate of change in accordance with the duty cycle schedule.

9. The non-transitory computer readable storage device of claim 8, wherein the constructing the duty cycle schedule comprises determining an attachment pattern based on the history of attachment events.

10. The non-transitory computer readable storage device of claim 8, wherein the operations further comprise identifying an attachment event associated with another femtocell device.

11. The non-transitory computer readable storage device of claim 10, wherein the operations further comprise determining a reuse interval that relates to an interval between a first time associated with the attachment event and a second time associated with a second attachment event associated with the femtocell device.

12. The non-transitory computer readable storage device of claim 11, wherein the constructing the duty cycle schedule comprises constructing the duty cycle schedule based on the reuse interval.

13. The non-transitory computer readable storage device of claim 8, wherein the operations further comprise facilitating copying the duty cycle schedule to a storage medium associated with another femtocell device.

14. The non-transitory computer readable storage device of claim 13, wherein the operations further comprise determining a reuse plan to reuse the duty cycle schedule for the other femtocell device based on an identifier that is common to the femtocell device and the other femtocell device.

15. A method, comprising:

determining, by a system comprising a processor, a duty cycle schedule for a pilot signal of the femtocell device based on a history of attachment events between a macro cell device and the femtocell device;

identifying, by the system, a threshold rate of change in power over time for the pilot signal, wherein the threshold rate of change satisfies a defined slope function determined to mitigate an induced interference condition in a wireless environment in which the femtocell device operates; and

changing, by the system, a power of the pilot signal over time at a second rate of change that is less than the first rate of change, wherein the changing the power is in accordance with the duty cycle schedule.

16. The method of claim 15, wherein the determining the duty cycle schedule comprises determining an attachment pattern based on the history of attachment events.

17. The method of claim 15, further comprising identifying an attachment event associated with another femtocell device.

18. The method of claim 17, further comprising determining a reuse interval that relates to an interval between a first time associated with the attachment event and a second time associated with a second attachment event associated with the femtocell device.

19. The method of claim 18, wherein the determining the duty cycle schedule comprises determining the duty cycle schedule based on the reuse interval.

20. The method of claim 15, wherein the operations further comprise facilitating copying the duty cycle schedule to a memory associated with another femtocell device.