Almost Blank Subframe Allocation

• US 20150131600A1
• Filed: 01/26/2015
• Published: 05/14/2015
• Est. Priority Date: 10/29/2011
• Status: Active Grant

• Current Assignee: Comcast Cable Communications LLC (Comcast Corporation)
• Original Assignee: Ofinno Technologies, LLC
• Inventors: Dinan, Esmael Hejazi
• Granted Patent: US 9,326,286 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04H 20/42 Arrangements for resource management
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A first base station provides overlapping coverage area with each of a plurality of second base stations. Each of the plurality of second base stations transmits a message comprising a subframe allocation bitmap indicating a plurality of subframes. The plurality of subframes comprises a plurality of almost blank subframes. Base stations in the plurality of second base stations configure the same set of subframes as the plurality of almost blank subframes.

Claims

1. A method comprising:

a) providing, by a first base station, an overlapping coverage area with each of a plurality of second base stations;

b) transmitting, by said first base station, a first message first message comprising;

i) a first subframe allocation repetition period;

ii) a first subframe allocation offset; and

iii) a first subframe allocation bitmap indicating a first plurality of subframes, said first plurality of subframes comprising a first plurality of almost blank subframes; and

c) transmitting, by each of said plurality of second base stations, a second message comprising;

i) said first subframe allocation repetition period;

ii) said first subframe allocation offset; and

iii) a second subframe allocation bitmap indicating a second plurality of subframes, said second plurality of subframes comprising a second plurality of almost blank subframes different from said first plurality of almost blank subframes; and

wherein;

i) base stations in said plurality of second base stations configure the same set of subframes as said second plurality of almost blank subframes; and

ii) said first plurality of almost blank subframes and said second plurality of almost blank subframes do not substantially overlap in time.

2. The method of claim 1, further comprising, transmitting in an almost blank subframe, a common reference signal only in a control region.

3. The method of claim 1, wherein said first message and said second message are broadcasted using physical downlink shared channel.

4. The method of claim 1, wherein during a majority of symbols of an almost blank subframe of a base station:

no signal is transmitted by said base station;

or signals are transmitted at an almost blank subframe power level that is substantially lower than a transmit power during a non-almost blank subframe.

5. The method of claim 1, wherein said first base station is of a different base station type than said plurality of second base stations.

6. The method of claim 5, wherein said base station type is one of the following:

a) a femto base station type;

b) a pico base station type;

c) a micro base station type; and

d) a macro base station type.

7. The method of claim 1, further comprising transmitting, by said first base station to a wireless device, a unicast message comprising:

a) measurement subframe configuration of a primary carrier; and

b) measurement subframe configuration of a plurality of neighboring carriers.

8. The method of claim 1, wherein said first message further comprises a second pattern bitmap indicating a subset of a first plurality of almost blank subframes, said second pattern bitmap being employed to configure measurement parameters for a wireless device.

9. The method of claim 1, wherein said first base station decreases a number of almost blank subframes in said first plurality of almost blank subframes in response to an increase in traffic load of said first base station by an amount greater than a load value.

10. The method of claim 1, wherein frame and subframe transmissions of said first base station and each of said second plurality of base stations are substantially synchronized.

11. The method of claim 1, wherein said first base station increases a number of almost blank subframes in said first plurality of almost blank subframes in response to a decrease in the traffic load of said first base station by an amount greater than a load value.

12. The method of claim 1, further comprising transmitting, by said first base station, a third message to a base station in said plurality of second base stations, said third message comprising a first pattern bitmap indicating said first plurality of almost blank subframes.

13. The method of claim 1, wherein said first message further comprises:

a) a first measurement subframe allocation bitmap identifying a first plurality of measurement subframes, said first plurality of measurement subframes excluding said first plurality of almost blank subframes;

b) a second measurement subframe allocation bitmap identifying a second plurality of measurement subframes, said second plurality of measurement subframes excluding subframes in said first plurality of measurement subframes.

14. The method of claim 1, wherein said second message further comprises:

a) a third measurement subframe allocation bitmap identifying a third plurality of measurement subframes, said third plurality of measurement subframes excluding said second plurality of almost blank subframes;

b) a fourth measurement subframe allocation bitmap identifying a fourth plurality of measurement subframes, said fourth plurality of measurement subframes excluding subframes in said third plurality of measurement subframes.

15. The method of claim 1, wherein a second base station in said plurality of second base stations configures at least one parameter in said second message different than other base stations in said second plurality of base stations.

16. A method for use in a wireless network comprising a plurality of base station, the method comprising:

a) providing, by a first base station in said plurality of base stations, an overlapping coverage area with each of a plurality of second base stations;

b) transmitting, by said first base station, a first message first message comprising;

i) a first subframe allocation repetition period;

ii) a first subframe allocation offset; and

iii) a first subframe allocation bitmap indicating a first plurality of subframes, said first plurality of subframes comprising a first plurality of almost blank subframes; and

c) transmitting, by each of said plurality of second base stations in said plurality of base stations, a second message comprising;

i) said first subframe allocation repetition period;

ii) said first subframe allocation offset; and

iii) a second subframe allocation bitmap indicating a second plurality of subframes, said second plurality of subframes comprising a second plurality of almost blank subframes different from said first plurality of almost blank subframes; and

wherein;

i) base stations in said plurality of second base stations configure the same set of subframes as said second plurality of almost blank subframes; and

ii) said first plurality of almost blank subframes and said second plurality of almost blank subframes do not substantially overlap in time.

17. The method of claim 16, wherein said first message further comprises:

a) a first measurement subframe allocation bitmap identifying a first plurality of measurement subframes, said first plurality of measurement subframes excluding said first plurality of almost blank subframes;

b) a second measurement subframe allocation bitmap identifying a second plurality of measurement subframes, said second plurality of measurement subframes excluding subframes in said first plurality of measurement subframes.

18. The method of claim 16, wherein during a majority of symbols of an almost blank subframe of a base station:

no signal is transmitted by said base station;

or signals are transmitted at an almost blank subframe power level that is substantially lower than a transmit power during a non-almost blank subframe.

19. The method of claim 16, further comprising, transmitting in an almost blank subframe, a common reference signal only in a control region.

20. The method of claim 16, wherein said first base station is of a different base station type than said plurality of second base stations.