System and method for providing uplink inter cell interference coordination in a network environment

• US 9,918,314 B2
• Filed: 04/14/2015
• Issued: 03/13/2018
• Est. Priority Date: 04/14/2015
• 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
• Primary Examiner(s): MATTIS, JASON E
• Application Number:
  US14/686,598
• Publication Number:
  US 20160309356A1
• Time in Patent Office: 1,064 Days
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 28/0236 radio quality, e.g. interference, losses or delay
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/1268 of uplink data flows
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

A method is provided in one example embodiment and may include determining one or more uplink inter cell interference coordination (ICIC) parameters for a plurality of cells based, at least in part, on feedback information associated with the plurality of cells; exchanging interference information between neighboring cells; and scheduling uplink transmissions for user equipment served by the neighboring cells based, at least in part, on the uplink ICIC parameters and the interference information exchanged between neighboring cells. A method is provided in another example embodiment and may include determining a ratio relating a first portion of a frequency spectrum for assigning fractional frequency re-use resources to a second portion of the frequency spectrum for assigning re-use one resources; and updating the ratio relating the first portion and the second portion of the frequency spectrum to optimize throughput rates for the plurality of user equipment across the plurality of cells.

Claims

1. A method comprising:

determining one or more uplink inter cell interference coordination (ICIC) parameters by a central management entity for a plurality of cells based, at least in part, on feedback information associated with the plurality of cells, wherein the feedback information is associated, at least in part, with signal strength information associated with the plurality of cells and wherein the uplink ICIC parameters include, at least in part, a low interference power spectral density (PSD) level and a medium interference PSD level, wherein the medium interference PSD level is based on an average interference level determined for the plurality of cells for user equipment served by each of the plurality of cells;

communicating the uplink ICIC parameters to each of the plurality of cells;

exchanging interference information between neighboring cells of the plurality of cells, wherein the interference information includes, at least in part, interference guarantees for certain transmissions between each neighboring cell of the plurality of cells based on the low interference PSD level and the medium interference PSD level; and

scheduling uplink transmissions for user equipment served by the neighboring cells based, at least in part, on the uplink ICIC parameters and the interference information exchanged between neighboring cells, wherein the uplink transmissions are scheduled in at least one of a re-use one portion and a fractional frequency re-use (FFR) portion of a frequency spectrum available for the uplink transmissions.

2. The method of claim 1, wherein determining the one or more uplink ICIC parameters further comprises:

setting the low interference PSD level, wherein the low interference PSD level is set to allow a certain percentage of cell edge user equipment served by each of the neighboring cells to achieve a Signal-to-Interference-plus-Noise Ratio of 7 decibels (dB).

3. The method of claim 1, wherein determining the one or more uplink ICIC parameters further comprises:

determining a number of neighboring cells for each of the plurality of cells based, at least in part, on the signal strength information, wherein one or more cells are determined to be neighboring another cell if their signal strength information is above a certain threshold;

determining a number of resources for uplink transmissions for the FFR portion of the frequency spectrum, wherein the number of resources for the uplink transmissions for the FFR portion of the frequency spectrum is inversely proportional to the number of neighboring cells for each of the plurality of cells; and

determining fractions of total resources for uplink transmissions for resource block regions of the re-use one portion and the FFR portion of the frequency spectrum.

4. The method of claim 3, wherein exchanging interference information between neighboring cells includes distributing High Interference Information (HII) messages over X2 interfaces between neighboring cells to coordinate high interference resource block (RB) guarantees and low interference RB guarantees for the FFR portion of the frequency spectrum based, at least in part, on the number of resources determined for uplink transmission for the FFR portion, the fractions of total resources for uplink transmissions, the low interference PSD level and the medium interference PSD level.

5. The method of claim 1, wherein the signal strength information includes Reference Signal Received Power (RSRP) information, the method further comprising:

receiving, by a particular cell of the plurality of cells, RSRP information from each of a plurality of user equipment (UE) served by the particular cell, wherein the RSRP information received from each UE includes, at least in part, a serving cell RSRP value for the particular cell and one or more neighboring cell RSRP values for one or more neighboring cells of the particular cell.

6. The method of claim 5, further comprising:

determining a number of UEs connected to the particular cell;

determining a number of UEs for which one or more neighboring cell RSRP values are above an RSRP threshold; and

including in the feedback information;

the number of UEs connected to the particular cell;

the number of UEs having one or more neighboring cell RSRP values above the RSRP threshold;

the serving cell RSRP value for each of the number of UEs having one or more neighboring cell RSRP values above the RSRP threshold; and

a cell identifier and a corresponding RSRP value for each of the one or neighboring cell RSRP values above the RSRP threshold.

7. The method of claim 5, further comprising:

determining one or more relative interference values for each of one or more neighboring cells of the particular cell for each of one or more UEs connected to the particular cell, wherein the each relative interference value is based on the serving cell RSRP value and a neighboring cell RSRP value for each of the one or more neighboring cells as received from each of the one or more UEs;

determining whether each relative interference value is above a relative interference threshold;

ordering each relative interference value that is above the relative interference threshold in a predetermined order;

determining a highest relative interference value for each of the one or more neighboring cells that is above the relative interference threshold; and

including in the feedback information the highest relative interference value and a cell identifier for each of the one or more neighboring cells that is above the relative interference threshold according to the predetermined order.

8. 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 one or more uplink inter cell interference coordination (ICIC) parameters for a plurality of cells based, at least in part, on feedback information associated with the plurality of cells, wherein the feedback information is associated, at least in part, with signal strength information associated with the plurality of cells and wherein the uplink ICIC parameters include, at least in part, a low interference power spectral density (PSD) level and a medium interference PSD level, wherein the medium interference PSD level is based on an average interference level determined for the plurality of cells for user equipment served by each of the plurality of cells;

communicating the uplink ICIC parameters to each of the plurality of cells;

exchanging interference information between neighboring cells of the plurality of cells, wherein the interference information includes, at least in part, interference guarantees for uplink transmissions to be scheduled between each neighboring cell of the plurality of cells according to the low interference PSD level and the medium interference PSD level; and

scheduling uplink transmissions for user equipment served by the neighboring cells based, at least in part, on the uplink ICIC parameters and the interference information exchanged between neighboring cells, wherein the uplink transmissions are scheduled in at least one of a re-use one portion and a fractional frequency re-use (FFR) portion of a frequency spectrum available for the uplink transmissions.

9. The media of claim 8, wherein determining the one or more uplink ICIC parameters further comprises:

setting the low interference PSD level, wherein the low interference PSD level is set to allow a certain percentage of cell edge user equipment served by each of the neighboring cells to achieve a Signal-to-Interference-plus-Noise Ratio of 7 decibels (dB).

10. The media of claim 8, wherein determining the one or more uplink ICIC parameters further comprises:

determining a number of neighboring cells for each of the plurality of cells based, at least in part, on the signal strength information, wherein one or more cells are determined to be neighboring another cell if their signal strength information is above a certain threshold;

determining a number of resources for uplink transmissions for the FFR portion of the frequency spectrum, wherein the number of resources for the uplink transmissions for the FFR portion of the frequency spectrum is inversely proportional the number of neighboring cells for each of the plurality of cells; and

determining a fraction of total resources to allocate for uplink transmissions for resource block regions of the re-use one portion and the FFR portion of the frequency spectrum.

11. The media of claim 8, wherein the signal strength information includes Reference Signal Received Power (RSRP) information, the operations further comprising:

receiving, by a particular cell of the plurality of cells, RSRP information from each of a plurality of user equipment (UE) served by the particular cell, wherein the RSRP information received from each UE includes, at least in part, a serving cell RSRP value for the particular cell and one or more neighboring cell RSRP values for one or more neighboring cells of the particular cell.

12. The media of claim 11, wherein the execution causes the processor to perform further operations comprising:

determining a number of UEs connected to the particular cell;

determining a number of UEs for which one or more neighboring cell RSRP values are above an RSRP threshold; and

including in the feedback information;

the number of UEs connected to the particular cell;

the number of UEs having one or more neighboring cell RSRP values above the RSRP threshold;

the serving cell RSRP value for each of the number of UEs having one or more neighboring cell RSRP values above the RSRP threshold; and

a cell identifier and a corresponding RSRP value for each of the one or neighboring cell RSRP values above the RSRP threshold.

13. The media of claim 11, wherein the execution causes the processor to perform further operations comprising:

determining one or more relative interference values for each of one or more neighboring cells of the particular cell for each of one or more UEs connected to the particular cell, wherein the each relative interference value is based on the serving cell RSRP value and a neighboring cell RSRP value for each of the one or more neighboring cells as received from each of the one or more UEs;

determining whether each relative interference value is above a relative interference threshold;

ordering each relative interference value that is above the relative interference threshold in a predetermined order;

determining a highest relative interference value for each of the one or more neighboring cells that is above the relative interference threshold; and

including in the feedback information the highest relative interference value and a cell identifier for each of the one or more neighboring cells that is above the relative interference threshold according to the predetermined order.

14. A system, comprising:

at least one memory element for storing data; and

at least one processor that executes instructions associated with the data, wherein executing the instructions causes the system to perform operations, comprising;

determining one or more uplink inter cell interference coordination (ICIC) parameters for a plurality of cells based, at least in part, on feedback information associated with the plurality of cells, wherein the feedback information is associated, at least in part, with signal strength information associated with the plurality of cells and wherein the uplink ICIC parameters include, at least in part, a low interference power spectral density (PSD) level and a medium interference PSD level, wherein the medium interference PSD level is based on an average interference level determined for the plurality of cells for user equipment served by each of the plurality of cells;

communicating the uplink ICIC parameters to each of the plurality of cells;

exchanging interference information between neighboring cells of the plurality of cells, wherein the interference information includes, at least in part, interference guarantees for certain transmissions between each neighboring cell of the plurality of cells based on the low interference PSD level and the medium interference PSD level; and

scheduling uplink transmissions for user equipment served by the neighboring cells based, at least in part, on the uplink ICIC parameters and the interference information exchanged between neighboring cells, wherein the uplink transmissions are scheduled in at least one of a re-use one portion and a fractional frequency re-use (FFR) portion of a frequency spectrum available for the uplink transmissions.

15. The system of claim 14, wherein determining the one or more uplink ICIC parameters further comprises at least one of:

setting the low interference PSD level, wherein the low interference PSD level is set to allow a certain percentage of cell edge user equipment served by each of the neighboring cells to achieve a Signal-to-Interference-plus-Noise Ratio of 7 decibels (dB).

16. The system of claim 15, wherein determining the one or more uplink ICIC parameters further comprises:

determining a number of neighboring cells for each of the plurality of cells based, at least in part, on the signal strength information, wherein one or more cells are determined to be neighboring another cell if their signal strength information is above a certain threshold;

determining a number of resources for uplink transmissions for the FFR portion of the frequency spectrum, wherein the number of resources for the uplink transmissions for the FFR portion of the frequency spectrum is inversely proportional to the number of neighboring cells for each of the plurality of cells; and

determining a fraction of total resources to allocate for uplink transmissions for resource block regions of the re-use one portion and the FFR portion of the frequency spectrum.

17. The system of claim 14, wherein exchanging interference information between neighboring cells includes distributing High Interference Information (HII) messages over X2 interfaces between neighboring cells to coordinate high interference resource block (RB) guarantees and low interference RB guarantees for the FFR portion of the frequency spectrum based, at least in part, on the number of resources determined for uplink transmission for the FFR portion, the fractions of total resources for uplink transmissions, the low interference PSD level and the medium interference PSD level.

18. The system of claim 14, wherein executing the instructions causes the system to perform further operations, comprising:

determining a number of UEs connected to the particular cell;

determining a number of UEs for which one or more neighboring cell RSRP values are above an RSRP threshold; and

including in the feedback information;

the number of UEs connected to the particular cell;

the number of UEs having one or more neighboring cell RSRP values above the RSRP threshold;

the serving cell RSRP value for each of the number of UEs having one or more neighboring cell RSRP values above the RSRP threshold; and

a cell identifier and a corresponding RSRP value for each of the one or neighboring cell RSRP values above the RSRP threshold.

19. The system of claim 18, wherein executing the instructions causes the system to perform further operations, comprising:

determining one or more relative interference values for each of one or more neighboring cells of the particular cell for each of one or more UEs connected to the particular cell, wherein the each relative interference value is based on the serving cell RSRP value and a neighboring cell RSRP value for each of the one or more neighboring cells as received from each of the one or more UEs;

determining whether each relative interference value is above a relative interference threshold;

ordering each relative interference value that is above the relative interference threshold in a predetermined order;

determining a highest relative interference value for each of the one or more neighboring cells that is above the relative interference threshold; and

including in the feedback information the highest relative interference value and a cell identifier for each of the one or more neighboring cells that is above the relative interference threshold according to the predetermined order.