System and method to provide small cell power control and load balancing for high mobility user equipment in a network environment

• US 9,813,970 B2
• Filed: 01/20/2016
• Issued: 11/07/2017
• Est. Priority Date: 01/20/2016
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Madan, Ritesh K., Haghani, Ehsan, Nabar, Rohit Umesh
• Primary Examiner(s): Kassim, Khaled
• Assistant Examiner(s): ALI, SYED
• Application Number:
  US15/002,187
• Publication Number:
  US 20170208526A1
• Time in Patent Office: 657 Days
• CPC Class Codes: H04W 36/008375 based on historical data
• CPC Class Codes: H04W 36/0094 Definition of hand-off measurement parameters
• CPC Class Codes: H04W 36/22 for handling the traffic
• CPC Class Codes: H04W 36/324 by mobility data, e.g. speed data
• CPC Class Codes: H04W 52/143 Downlink power control
• 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 52/285 taking into account the mobility of the user
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

A method is provided in one example embodiment and may include generating feedback information by a small cell radio and a macro cell radio; setting a high mobility handover threshold for the macro cell radio based, at least in part, on the feedback information, wherein the high mobility handover threshold is used to trigger handover of one or more high mobility user equipment (UE) associated with the macro cell radio to the small cell radio; and setting a maximum downlink transmit power for the small cell radio based, at least in part, on the feedback information and the high mobility handover threshold.

Claims

1. A method comprising:

generating feedback information by a small cell radio and a macro cell radio;

setting a high mobility handover threshold for the macro cell radio based, at least in part, on the feedback information, wherein the high mobility handover threshold is used to trigger handover of one or more high mobility user equipment (UE) associated with the macro cell radio to the small cell radio; and

setting a maximum downlink transmit power for the small cell radio based, at least in part, on the feedback information and the high mobility handover threshold, wherein setting the maximum downlink transmit power for the small cell radio further comprises;

evaluating the high mobility handover threshold for the macro cell radio in relation to a maximum Signal-to-Interference-Plus-Noise Ratio (SINR) and a minimum SINR expected for one or more UE associated with the macro cell radio;

evaluating a Radio Link Failure (RLF) failure rate for one or more low mobility UE associated with the small cell radio in relation to a maximum RLF failure rate for the small cell radio; and

setting the maximum downlink transmit power for the small cell radio to limit interference toward the one or more UE associated with the macro cell radio and to maintain the RLF failure rate of the one or more low mobility UE associated with the small cell radio below the maximum RLF failure rate, wherein based on the maximum downlink transmit power for the small cell radio being reduced, setting the high mobility handover threshold for the macro cell radio further comprises reducing the high mobility handover threshold in proportion to an amount that the maximum downlink transmit power for the small cell radio is reduced.

2. The method of claim 1, further comprising:

receiving the feedback information by a central management system, wherein the central management system performs setting the high mobility handover threshold for the macro cell radio and setting the maximum downlink transmit power for the small cell radio.

3. The method of claim 1, wherein setting the high mobility handover threshold for the macro cell radio further comprises:

evaluating a rate of undesirable handovers to the small cell radio of the one or more high mobility UE associated with the macro cell radio in relation to a maximum rate of undesirable handovers and a minimum rate of undesirable handovers for the macro cell radio;

evaluating a load of the macro cell radio in relation to a maximum load and a minimum load for the macro cell radio; and

setting the high mobility handover threshold for the macro cell radio to reduce the rate of undesirable handovers below the maximum rate of undesirable handovers when the load of the macro cell radio is below the maximum load for the macro cell radio.

4. The method of claim 1, wherein feedback information generated by the macro cell radio comprises one or more of:

mobility information for the one or more UE associated with the macro cell radio;

radio link failure (RLF) information for the one or more UE associated with the macro cell radio;

measurement report information for the one or more UE associated with the macro cell radio;

loading statistics for the macro cell radio;

a rate of undesirable handovers of the one or more UE associated with the macro cell radio;

a transmit power of the macro cell radio;

the high mobility handover threshold for the macro cell radio; and

a Fractional Frequency Reuse (FFR) pattern for the macro cell radio.

5. The method of claim 4, wherein mobility information for a particular UE comprises:

mobility history information for the particular UE, wherein the mobility history information includes a list one or more cell radios to which the particular UE has been previously connected and a time of stay associated with each of the one or more cell radios contained in the list.

6. The method of claim 1, wherein feedback information generated by the small cell radio comprises one or more of:

mobility information for one or more UE associated with the small cell radio;

radio link failure (RLF) information for the one or more UE associated with the small cell radio;

measurement report information for the one or more UE associated with the small cell radio;

a Radio Link Failure (RLF) failure rate for the one or more UE associated with the small cell radio;

a maximum downlink transmit power of the small cell radio; and

a Fractional Frequency Reuse (FFR) pattern for the small cell radio.

7. 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:

generating feedback information by a small cell radio and a macro cell radio;

setting a high mobility handover threshold for the macro cell radio based, at least in part, on the feedback information, wherein the high mobility handover threshold is used to trigger handover of one or more high mobility user equipment (UE) associated with the macro cell radio to the small cell radio; and

setting a maximum downlink transmit power for the small cell radio based, at least in part, on the feedback information and the high mobility handover threshold, wherein setting the maximum downlink transmit power for the small cell radio further comprises;

evaluating the high mobility handover threshold for the macro cell radio in relation to a maximum Signal-to-Interference-Plus-Noise Ratio (SINR) and a minimum SINR expected for one or more UE associated with the macro cell radio;

evaluating a Radio Link Failure (RLF) failure rate for one or more low mobility UE associated with the small cell radio in relation to a maximum RLF failure rate for the small cell radio; and

setting the maximum downlink transmit power for the small cell radio to limit interference toward the one or more UE associated with the macro cell radio and to maintain the RLF failure rate of the one or more low mobility UE associated with the small cell radio below the maximum RLF failure rate, wherein based on the maximum downlink transmit power for the small cell radio being reduced, setting the high mobility handover threshold for the macro cell radio further comprises reducing the high mobility handover threshold in proportion to an amount that the maximum downlink transmit power for the small cell radio is reduced.

8. The media of claim 7, the operations further comprising:

receiving the feedback information by a central management system, wherein the central management system performs setting the high mobility handover threshold for the macro cell radio and setting the maximum downlink transmit power for the small cell radio.

9. The media of claim 7, wherein setting the high mobility handover threshold for the macro cell radio further comprises:

evaluating a rate of undesirable handovers to the small cell radio of the one or more high mobility UE associated with the macro cell radio in relation to a maximum rate of undesirable handovers and a minimum rate of undesirable handovers for the macro cell radio;

evaluating a load of the macro cell radio in relation to a maximum load and a minimum load for the macro cell radio; and

setting the high mobility handover threshold for the macro cell radio to reduce the rate of undesirable handovers below the maximum rate of undesirable handovers when the load of the macro cell radio is below the maximum load for the macro cell radio.

10. The media of claim 7, wherein feedback information generated by the macro cell radio comprises one or more of:

mobility information for the one or more UE associated with the macro cell radio;

radio link failure (RLF) information for the one or more UE associated with the macro cell radio;

measurement report information for the one or more UE associated with the macro cell radio;

loading statistics for the macro cell radio;

a rate of undesirable handovers of the one or more UE associated with the macro cell radio;

a transmit power of the macro cell radio;

the high mobility handover threshold for the macro cell radio; and

a Fractional Frequency Reuse (FFR) pattern for the macro cell radio.

11. The media of claim 10, wherein mobility information for a particular UE comprises:

mobility history information for the particular UE, wherein the mobility history information includes a list one or more cell radios to which the particular UE has been previously connected and a time of stay associated with each of the one or more cell radios contained in the list.

12. The media of claim 7, wherein feedback information generated by the small cell radio comprises one or more of:

mobility information for one or more UE associated with the small cell radio;

radio link failure (RLF) information for the one or more UE associated with the small cell radio;

measurement report information for the one or more UE associated with the small cell radio;

a Radio Link Failure (RLF) failure rate for the one or more UE associated with the small cell radio;

a maximum downlink transmit power of the small cell radio; and

a Fractional Frequency Reuse (FFR) pattern for the small cell radio.

13. 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 processor and the memory element cooperate such that the system is configured for;

generating feedback information by a small cell radio and a macro cell radio;

setting a high mobility handover threshold for the macro cell radio based, at least in part, on the feedback information, wherein the high mobility handover threshold is used to trigger handover of one or more high mobility user equipment (UE) associated with the macro cell radio to the small cell radio; and

setting a maximum downlink transmit power for the small cell radio based, at least in part, on the feedback information and the high mobility handover threshold, wherein setting the maximum downlink transmit power for the small cell radio further comprises;

evaluating the high mobility handover threshold for the macro cell radio in relation to a maximum Signal-to-Interference-Plus-Noise Ratio (SINR) and a minimum SINR expected for one or more UE associated with the macro cell radio;

evaluating a Radio Link Failure (RLF) failure rate for one or more low mobility UE associated with the small cell radio in relation to a maximum RLF failure rate for the small cell radio; and

setting the maximum downlink transmit power for the small cell radio to limit interference toward the one or more UE associated with the macro cell radio and to maintain the RLF failure rate of the one or more low mobility UE associated with the small cell radio below the maximum RLF failure rate, wherein based on the maximum downlink transmit power for the small cell radio being reduced, setting the high mobility handover threshold for the macro cell radio further comprises reducing the high mobility handover threshold in proportion to an amount that the maximum downlink transmit power for the small cell radio is reduced.

14. The system of claim 13, wherein the system is further configured for:

receiving the feedback information by a central management system, wherein the central management system performs setting the high mobility handover threshold for the macro cell radio and setting the maximum downlink transmit power for the small cell radio.

15. The system of claim 13, wherein setting the high mobility handover threshold for the macro cell radio further comprises:

evaluating a rate of undesirable handovers to the small cell radio of the one or more high mobility UE associated with the macro cell radio in relation to a maximum rate of undesirable handovers and a minimum rate of undesirable handovers for the macro cell radio;

evaluating a load of the macro cell radio in relation to a maximum load and a minimum load for the macro cell radio; and

setting the high mobility handover threshold for the macro cell radio to reduce the rate of undesirable handovers below the maximum rate of undesirable handovers when the load of the macro cell radio is below the maximum load for the macro cell radio.

16. The system of claim 13, wherein feedback information generated by the macro cell radio comprises one or more of:

mobility information for the one or more UE associated with the macro cell radio;

radio link failure (RLF) information for the one or more UE associated with the macro cell radio;

measurement report information for the one or more UE associated with the macro cell radio;

loading statistics for the macro cell radio;

a rate of undesirable handovers of the one or more UE associated with the macro cell radio;

a transmit power of the macro cell radio;

the high mobility handover threshold for the macro cell radio; and

a Fractional Frequency Reuse (FFR) pattern for the macro cell radio.

17. The system of claim 16, wherein mobility information for a particular UE comprises:

mobility history information for the particular UE, wherein the mobility history information includes a list one or more cell radios to which the particular UE has been previously connected and a time of stay associated with each of the one or more cell radios contained in the list.

18. The system of claim 13, wherein feedback information generated by the small cell radio comprises one or more of:

mobility information for one or more UE associated with the small cell radio;

radio link failure (RLF) information for the one or more UE associated with the small cell radio;

measurement report information for the one or more UE associated with the small cell radio;

a Radio Link Failure (RLF) failure rate for the one or more UE associated with the small cell radio;

a maximum downlink transmit power of the small cell radio; and

a Fractional Frequency Reuse (FFR) pattern for the small cell radio.