System and method to facilitate small cell uplink power control in a network environment

• US 9,860,852 B2
• Filed: 08/24/2015
• Issued: 01/02/2018
• Est. Priority Date: 07/25/2015
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Madan, Ritesh K., Nabar, Rohit Umesh, Chandrasekhar, Vikram, Shirali, Kedar Durgadas, Zhao, Qing
• Primary Examiner(s): PHU, SANH D
• Application Number:
  US14/833,519
• Publication Number:
  US 20170026915A1
• Time in Patent Office: 862 Days
• Field of Search: 455501
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/242 taking into account path loss
• 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 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method is provided in one example embodiment and may include calculating, by one or more of a plurality of small cell radios, one or more sets of candidate power control parameters using a first interference constraint for uplink user equipment (UE) transmissions for UE served by the one or more of the plurality of small cell radios; determining, at a central management entity, whether an average of a sum of an expected interference for UE associated with the plurality of small cell radios violates a second interference constraint for any of the one or more sets of candidate power control parameters; and generating one or more messages for each of the plurality of small cell radios identifying one or more particular sets of power control parameters that provide for meeting the second interference constraint.

Claims

1. A method comprising:

determining user equipment (UE) path loss information associated with one or more UE served by one or more small cell radios;

determining macro path loss information associated with each of the one or more small cell radios and a macro cell radio;

determining, at a central management entity, one or more sets of optimized power control parameters for uplink UE transmissions for the one or more UE served by the one or more small cell radios based on the determined UE path loss information and the determined macro path loss information, wherein the one or more sets of optimized power control parameters satisfy a first interference constraint associated with limiting interference between the one or more small cell radios and satisfy a second interference constraint associated with limiting interference toward the macro cell radio;

generating one or more messages for each of the one or more small cell radios identifying the one or more sets of optimized power control parameters; and

setting, by each small cell radio of the one or more small cell radios, uplink transmit power for each UE served by each small cell radio based, at least in part, on the identified one or more sets of optimized power control parameters.

2. The method of claim 1, wherein each set of optimized power control parameters includes:

a first power control parameter associated with a power offset for UE transmissions toward a particular small cell radio; and

a second power control parameter associated with an amount of UE path loss between UE served by the particular small cell radio that is inverted for UE transmissions toward the particular small cell radio.

3. The method of claim 1, wherein the UE path loss information includes, at least in part:

a maximum estimated UE path loss for one or more cell edge UE served by a particular small cell radio; and

a maximum estimated UE path loss for one or more cell interior UE served by the particular small cell radio.

4. The method of claim 1, wherein the macro path loss information is based, at least in part, on signal strength information for the macro cell radio as measured by one or more UE served by a particular small cell radio.

5. The method of claim 1, wherein the UE path loss information and the macro path loss information are determined by a particular small cell radio that is experiencing the highest interference from one or more macro UE served by the macro cell radio.

6. The method of claim 1, wherein determining the one or more sets of optimized power control parameters further comprises:

calculating, at the central management entity, one or more sets of candidate power control parameters that meet the first interference constraint for one or more Signal to Interference plus Noise Ratio (SINR) threshold values associated with cell edge UE served and one or more SINR threshold values associated with cell interior UE served by a particular small cell radio.

7. The method of claim 6, further comprising:

determining whether an average of a sum of an expected interference for the one or more UE served by the one or more small cell radios satisfies the second interference constraint for any of the one or more sets of candidate power control parameters; and

identifying the one or more sets of optimized power control parameters as those one or more corresponding sets of power control parameters that satisfy the second interference constraint.

8. The method of claim 1, wherein the central management entity is a Self- Organizing Network (SON) management system in communication with each of the one or more small cell radios.

9. One or more non-transitory tangible media encoding logic that includes instructions for execution by a processor, wherein the execution causes the processor to perform operations, comprising:

determining user equipment (UE) path loss information associated with one or more UE served by one or more small cell radios;

determining macro path loss information associated with each of the one or more small cell radios and a macro cell radio;

determining, at a central management entity, one or more sets of optimized power control parameters for uplink UE transmissions for the one or more UE served by the one or more small cell radios based on the determined UE path loss information and the determined macro path loss information, wherein the one or more sets of optimized power control parameters satisfy a first interference constraint associated with limiting interference between the one or more small cell radios and satisfy a second interference constraint associated with limiting interference toward the macro cell radio;

generating one or more messages for each of the one or more small cell radios identifying the one or more sets of optimized power control parameters; and

setting, by each small cell radio of the one or more small cell radios, uplink transmit power for each UE served by each small cell radio based, at least in part, on the identified one or more sets of optimized power control parameters.

10. The media of claim 9, wherein each set of optimized power control parameters includes:

a first power control parameter associated with a power offset for UE transmissions toward a particular small cell radio; and

a second power control parameter associated with an amount of UE path loss between UE served by the particular small cell radio that is inverted for UE transmissions toward the particular small cell radio.

11. The media of claim 9, wherein the UE path loss information includes, at least in part:

a maximum estimated UE path loss for one or more cell edge UE served by a particular small cell radio; and

a maximum estimated UE path loss for one or more cell interior UE served by the particular small cell radio.

12. The media of claim 9, wherein the macro path loss information is based, at least in part, on signal strength information for the macro cell radio as measured by one or more UE served by a particular small cell radio.

13. The media of claim 9, wherein the UE path loss information and the macro path loss information are determined by a particular small cell radio that is experiencing the highest interference from one or more macro UE served by the macro cell radio.

14. The media of claim 9, wherein determining the one or more sets of optimized power control parameters further comprises:

calculating, at the central management entity, one or more sets of candidate power control parameters that meet the first interference constraint for one or more Signal to Interference plus Noise Ratio (SINR) threshold values associated with cell edge UE served and one or more SINR threshold values associated with cell interior UE served by a particular small cell radio.

15. The media of claim 14, wherein the execution causes the processor to perform further operations, comprising:

determining whether an average of a sum of an expected interference for the one or more UE served by the one or more small cell radios satisfies the second interference constraint for any of the one or more sets of candidate power control parameters; and

identifying the one or more sets of optimized power control parameters as those one or more corresponding sets of power control parameters that satisfy the second interference constraint.

16. A communication system comprising:

a central management entity comprising at least one memory element for storing data and at least one processor that executes instructions associated with the data, the central management entity being adapted when executed by the at least one processor to;

determine user equipment (UE) path loss information associated with one or more UE served by one or more small cell radios;

determine macro path loss information associated with each of the one or more small cell radios and a macro cell radio;

determine, at the central management entity, one or more sets of optimized power control parameters for uplink UE transmissions for the one or more UE served by the one or more small cell radios based on the determined UE path loss information and the determined macro path loss information, wherein the one or more sets of optimized power control parameters satisfy a first interference constraint associated with limiting interference between the one or more small cell radios and satisfy a second interference constraint associated with limiting interference toward the macro cell radio; and

generate one or more messages for each of the one or more small cell radios identifying the one or more sets of optimized power control parameters; and

setting, by each small cell radio of the one or more small cell radios, uplink transmit power for each UE served by each small cell radio based, at least in part, on the identified one or more sets of optimized power control parameters.

17. The communication system of claim 16, wherein each set of optimized power control parameters includes:

a first power control parameter associated with a power offset for UE transmissions toward a particular small cell radio; and

a second power control parameter associated with an amount of UE path loss between UE served by the particular small cell radio that is inverted for UE transmissions toward the particular small cell radio.

18. The communication system of claim 16, wherein the UE path loss information includes, at least in part:

a maximum estimated UE path loss for one or more cell edge UE served by a particular small cell radio; and

a maximum estimated UE path loss for one or more cell interior UE served by the particular small cell radio.

19. The communication system of claim 16, wherein determining the one or more sets of optimized power control parameters further comprises:

calculating, at the central management entity, one or more sets of candidate power control parameters that meet the first interference constraint for one or more Signal to Interference plus Noise Ratio (SINR) threshold values associated with cell edge UE served and one or more SINR threshold values associated with cell interior UE served by a particular small cell radio.

20. The communication system of claim 19, the central management entity being further adapted when executed by the at least one processor to:

determine whether an average of a sum of an expected interference for the one or more UE served by the one or more small cell radios satisfies the second interference constraint for any of the one or more sets of candidate power control parameters; and

identify the one or more sets of optimized power control parameters as those one or more corresponding sets of power control parameters that satisfy the second interference constraint.