Method, apparatus and computer readable medium for associating user equipment with a cell

• US 8,559,917 B1
• Filed: 03/30/2012
• Issued: 10/15/2013
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Deb, Supratim, Monogioudis, Pantelis
• Primary Examiner(s): LE, DANH C
• Application Number:
  US13/435,388
• Publication Number:
  US 20130260712A1
• Time in Patent Office: 564 Days
• Field of Search: 455/446, 455/405, 455/501, 455/450
• US Class Current: 455/405
• CPC Class Codes: H04M 15/80 Rating or billing plans; Tariff determination aspects
• CPC Class Codes: H04M 15/8033 location-dependent, e.g. business or home
• CPC Class Codes: H04W 4/24 Accounting or billing
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

The method includes determining one or more almost blank subframes (ABS) associated with a macro cell and associating a user equipment with one of the macro cell and a small cell using at least one of the one or more ABS based on one or more market prices associated with the small cell and the macro cell such that the determining and associating occurs jointly.

Claims

1. A method for wireless communication, comprising:

associating a user equipment with one of a macro cell and a small cell using one or more almost blank subframes (ABS) offered by the macro cell, one or more market prices related to associating with the macro cell and the small cell, and a utility that accounts for user equipment throughput based on potential associations.

2. The method of claim 1, prior to the associating step, further comprising:

offering, by one or more interfering macro cells of the small cell, a plurality of ABS based on the utility.

3. The method of claim 2, wherein the utility is based on a logarithm of data rates of a plurality of user equipment and user equipment location, a downlink Signal to Interference plus Noise Ratio (SINR) from macro cell transmission and a downlink SINR from small cell transmission over ABS and non-ABS subframes.

4. The method of claim 3, wherein

the logarithm is Σ

_u log(R_u);

u is the user equipment element of the plurality of user equipment being summed;

R_u is a throughput associated with user equipment (u);

the throughput is based on the user equipment location, the downlink SINR from macro cell transmission and the downlink SINR from small cell transmission over ABS and non-ABS subframes; and

Σ

_u log(R_u) is maximized over the plurality of user equipment.

5. The method of claim 2, wherein the utility is based on a solution minimizing a sum of backlogs of a plurality of user equipment.

6. The method of claim 1, wherein

the associating is iterated a number of times,

during each iteration the one or more market prices are updated based on a gradient descent plan, and

the associating uses the one or more market prices of the current iteration.

7. The method of claim 6, wherein the gradient decent plan reaches a global maxima for a given network configuration.

8. The method of claim 7, further comprising:

determining an average number of ABSs across all iterations,

determining an average throughput for each user equipment across all iterations, wherein the average number of ABSs and the average throughput for each user equipment converges based on a fractional solution.

9. The method of claim 8 wherein the fractional solution results in at least one of the plurality of user equipment being associated with both the macro cell and the small cell on a time-sharing basis.

10. The method of claim 9, wherein the fractional solution is rounded to an integral solution without violating a set of feasibility constraints and produces an integer ABS offering of user equipment associations to one of the small cell and the macro cell.

11. The method of claim 10, further comprising:

mapping the user equipment associations to one or more cell selection bias value such that a new set of user equipment associations obtained after applying the cell selection bias is approximates the user equipment associations.

12. The method of claim 1, wherein one of the one or more market prices includes a price the user equipment pays to associate with the small cell.

13. The method of claim 1, wherein one of the one or more market prices includes a price the user equipment pays to associate with the macro cell.

14. The method of claim 1, wherein one of the one or more market prices includes a price the user equipment pays to use the one or more ABS.

15. The method of claim 1, wherein one of the one or more market prices includes a price associated with one or more interfering macro cells.

16. The method of claim 1, wherein one of the one or more market prices includes a price the small cell pays for the macro cell to remain silent during a subframe period.

17. The method of claim 1, wherein one of the one or more market prices includes a price the user equipment is willing to pay for associating with one of the macro cell and the small cell.