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

• US 9,648,569 B2
• Filed: 07/25/2015
• Issued: 05/09/2017
• 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:
  US14/809,201
• Publication Number:
  US 20170026914A1
• Time in Patent Office: 654 Days
• Field of Search: 455501
• 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 52/243 taking into account interferences
• 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]

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:

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;

receiving, at a central management entity, the one or more sets of candidate power control parameters from each of the one or more of the plurality of small cell radios;

determining, at the 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;

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; and

setting, by each small cell radio of the plurality of 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 particular sets of power control parameters.

2. The method of claim 1, wherein each set of 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 path loss between UE and 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 first interference constraint is associated, at least in part, with interference generated towards each of the one or more of the plurality of small cell radios by one or more UE associated with at least one macro cell radio.

4. The method of claim 1, wherein the second interference constraint is associated, at least in part, with interference generated by the UE associated with the plurality of small cell radios towards at least one macro cell radio.

5. The method of claim 1, wherein for a particular small cell radio calculating a particular set of candidate power control parameters further comprises:

setting a first expected Signal to Interference plus Noise Ratio (SINR) threshold value associated with cell edge UE served by the particular small cell radio for the first interference constraint;

setting a second expected SINR threshold value associated with cell interior UE served by the particular small cell radio for the first interference constraint;

calculating the particular set of candidate power control parameters for the particular small cell radio using the first expected SINR threshold value and the second expected SINR threshold value for the first interference constraint; and

generating a message toward the central management entity including the particular set of candidate power control parameters.

6. The method of claim 5, further comprising:

reducing at least one of the second expected SINR threshold value associated with cell interior UE or the first expected SINR threshold value associated with cell edge UE if the central management entity determines that the second interference constraint is violated; and

repeating the calculating and the generating for the particular small cell radio until the central management entity determines that the second interference constraint is satisfied.

7. The method of claim 1, wherein for a particular small cell radio calculating sets of candidate power control parameters further comprises:

setting a first range of first expected Signal to Interference plus Noise Ratio (SINR) threshold values associated with cell edge UE served by the particular small cell radio for the first interference constraint;

setting a second range of second expected SINR threshold values associated with cell interior UE served by the particular small cell radio for the first interference constraint;

calculating sets of candidate power control parameters for the particular small cell radio using each of the first expected SINR threshold value of the first range and each of the second expected SINR threshold value of the second range for the first interference constraint; and

generating one or more messages toward the central management entity including the sets of candidate power control parameters.

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 plurality of small cell radios.

9. One or more non-transitory tangible media encoding logic that includes instructions for execution that when executed by a processor, is operable to perform operations comprising:

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;

receiving, at a central management entity, the one or more sets of candidate power control parameters from each of the one or more of the plurality of small cell radios;

determining, at the 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;

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; and

setting, by each small cell radio of the plurality of 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 particular sets of power control parameters.

10. The media of claim 9, wherein each set of 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 path loss between UE and 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 first interference constraint is associated, at least in part, with interference generated towards each of the one or more of the plurality of small cell radios by one or more UE associated with at least one macro cell radio.

12. The media of claim 9, wherein the second interference constraint is associated, at least in part, with interference generated by the UE associated with the plurality of small cell radios towards at least one macro cell radio.

13. The media of claim 9, wherein for a particular small cell radio calculating a particular set of candidate power control parameters further comprises:

setting a first expected Signal to Interference plus Noise Ratio (SINR) threshold value associated with cell edge UE served by the particular small cell radio for the first interference constraint;

setting a second expected SINR threshold value associated with cell interior UE served by the particular small cell radio for the first interference constraint;

calculating the particular set of candidate power control parameters for the particular small cell radio using the first expected SINR threshold value and the second expected SINR threshold value for the first interference constraint; and

generating a message toward the central management entity including the particular set of candidate power control parameters.

14. The media of claim 13, the operations further comprising:

reducing at least one of the second expected SINR threshold value associated with cell interior UE or the first expected SINR threshold value associated with cell edge UE if the central management entity determines that the second interference constraint is violated; and

repeating the calculating and the generating for the particular small cell radio until the central management entity determines that the second interference constraint is satisfied.

15. The media of claim 9, wherein for a particular small cell radio calculating sets of candidate power control parameters further comprises:

setting a first range of first expected Signal to Interference plus Noise Ratio (SINR) threshold values associated with cell edge UE served by the particular small cell radio for the first interference constraint;

setting a second range of second expected SINR threshold values associated with cell interior UE served by the particular small cell radio for the first interference constraint;

calculating sets of candidate power control parameters for the particular small cell radio using each of the first expected SINR threshold value of the first range and each of the second expected SINR threshold value of the second range for the first interference constraint; and

generating one or more messages toward the central management entity including the sets of candidate power control parameters.

16. A system, comprising:

at least one memory element for storing data; and

at least one processor that executes instructions associated with the data, wherein the at least one processor and the at least one memory element cooperate such that the system is configured for;

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;

receiving, at a central management entity, the one or more sets of candidate power control parameters from each of the one or more of the plurality of small cell radios;

determining, at the 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;

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; and

setting, by each small cell radio of the plurality of 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 particular sets of power control parameters.

17. The system of claim 16, wherein the first interference constraint is associated, at least in part, with interference generated towards each of the one or more of the plurality of small cell radios by one or more UE associated with at least one macro cell radio and wherein the second interference constraint is associated, at least in part, with interference generated by the UE associated with the plurality of small cell radios towards the at least one macro cell radio.

18. The system of claim 16, wherein for a particular small cell radio calculating a particular set of candidate power control parameters further comprises:

setting a first expected Signal to Interference plus Noise Ratio (SINR) threshold value associated with cell edge UE served by the particular small cell radio for the first interference constraint;

setting a second expected SINR threshold value associated with cell interior UE served by the particular small cell radio for the first interference constraint;

calculating the particular set of candidate power control parameters for the particular small cell radio using the first expected SINR threshold value and the second expected SINR threshold value for the first interference constraint; and

generating a message toward the central management entity including the particular set of candidate power control parameters.

19. The system of claim 18, wherein the system is further configured for:

reducing at least one of the second expected SINR threshold value associated with cell interior UE or the first expected SINR threshold value associated with cell edge UE if the central management entity determines that the second interference constraint is violated; and

repeating the calculating and the generating for the particular small cell radio until the central management entity determines that the second interference constraint is satisfied.

20. The system of claim 16, wherein for a particular small cell radio calculating sets of candidate power control parameters further comprises:

setting a first range of first expected Signal to Interference plus Noise Ratio (SINR) threshold values associated with cell edge UE served by the particular small cell radio for the first interference constraint;

setting a second range of second expected SINR threshold values associated with cell interior UE served by the particular small cell radio for the first interference constraint;

calculating sets of candidate power control parameters for the particular small cell radio using each of the first expected SINR threshold value of the first range and each of the second expected SINR threshold value of the second range for the first interference constraint; and

generating one or more messages toward the central management entity including the sets of candidate power control parameters.