Almost blank subframe in carrier aggregation
Methods, apparatus, and systems are described relating to wireless communications. A base station may transmit a message comprising a subframe allocation bitmap indicating a plurality of subframes. The indicated subframes may correspond to Almost Blank Subframes transmitted by the base station. The base station may transmit a message to a wireless device indicating measurement subframe allocation bitmaps. A first measurement subframe allocation bitmap may exclude the plurality of subframes. A second measurement subframe allocation bitmap may exclude subframes of the first measurement subframe allocation bitmap. These and other features are described.
1. A base station comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the base station to:
transmit a first message comprising a subframe allocation bitmap indicating a plurality of Almost Blank Subframes, wherein the plurality of Almost Blank Subframes consists of second, fourth, seventh, and ninth subframes of each frame in a plurality of frames;
transmit, to a wireless device, a first measurement subframe allocation bitmap indicating a first plurality of measurement subframes, of a primary carrier, that are not the plurality of Almost Blank Subframes;
transmit, to the wireless device, a second measurement subframe allocation bitmap indicating a second plurality of measurement subframes, of the primary carrier, different from the first plurality of measurement subframes; and
transmit a first Almost Blank Subframe at a power level that is lower than during a subframe that is not an Almost Blank Subframe.
2. The base station of claim 1 , wherein the first Almost Blank Subframe consists essentially of a common reference signal in a control region.
3. The base station of claim 1 , wherein the second measurement subframe allocation bitmap excludes the plurality of Almost Blank Subframes.
4. The base station of claim 1 , wherein the base station periodically receives, from the wireless device, channel state information for one or both of:
one or more subframes indicated in the first measurement subframe allocation bitmap; or
one or more subframes indicated in the second measurement subframe allocation bitmap.
5. A base station comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the base station to:
transmit a first message comprising a subframe allocation bitmap indicating a plurality of Almost Blank Subframes, wherein the plurality of Almost Blank Subframes consists of third and eighth subframes of each frame in a plurality of frames;
transmit, to a wireless device, a first measurement subframe allocation bitmap indicating a first plurality of measurement subframes, of a primary carrier, that are not the plurality of Almost Blank Subframes;
transmit, to the wireless device, a second measurement subframe allocation bitmap indicating a second plurality of measurement subframes, of the primary carrier, different from the first plurality of measurement subframes; and
transmit a first Almost Blank Subframe at a power level that is lower than during a subframe that is not an Almost Blank Subframe.
6. The base station of claim 5 , wherein the first Almost Blank Subframe consists essentially of a common reference signal in a control region.
7. The base station of claim 5 , wherein the second measurement subframe allocation bitmap excludes the plurality of Almost Blank Subframes.
8. The base station of claim 5 , wherein the device base station periodically receives, from the wireless device, channel state information for one or both of:
one or more subframes indicated in the first measurement subframe allocation bitmap; or
one or more subframes indicated in the second measurement subframe allocation bitmap.
9. A base station comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the base station to:
transmit a first message comprising a subframe allocation bitmap indicating a plurality of Almost Blank Subframes, wherein the plurality of Almost Blank Subframes consists of second, fourth, and eighth subframes of each frame in a plurality of frames;
transmit, to a wireless device, a first measurement subframe allocation bitmap indicating a first plurality of measurement subframes, of a primary carrier, that are not the plurality of Almost Blank Subframes;
transmit, to the wireless device, a second measurement subframe allocation bitmap indicating a second plurality of measurement subframes, of the primary carrier, different from the first plurality of measurement subframes; and
transmit a first Almost Blank Subframe at a power level that is lower than during a subframe that is not an Almost Blank Subframe.
10. The base station of claim 9 , wherein the first Almost Blank Subframe consists essentially of a common reference signal in a control region.
11. The base station of claim 9 , wherein the second measurement subframe allocation bitmap excludes the plurality of Almost Blank Subframes.
12. The base station of claim 9 , wherein the base station periodically receives, from the wireless device, channel state information for:
one or more subframes indicated in the first measurement subframe allocation bitmap; or
one or more subframes indicated in the second measurement subframe allocation bitmap.
13. The base station of claim 9 , wherein the instructions, when executed by the one or more processors, further cause the base station to:
transmit, based on a decrease in traffic load by an amount greater than a first value, a third message comprising a second subframe allocation bitmap indicating a second plurality of Almost Blank Subframes, wherein the second plurality of Almost Blank Subframes consists of second, fourth, seventh, and ninth subframes of each frame in a second plurality of frames.
14. The base station of claim 9 , wherein the instructions, when executed by the one or more processors, further cause the base station to:
transmit, based on an increase in traffic load by an amount greater than a first value, a third message comprising a second subframe allocation bitmap indicating a second plurality of Almost Blank Subframes, wherein the second plurality of Almost Blank Subframes consists of third and eighth subframes of each frame in a second plurality of frames.
15. A base station comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the base station to:
transmit a first message comprising a subframe allocation bitmap indicating a plurality of Almost Blank Subframes, wherein the plurality of Almost Blank Subframes consists of third, seventh, and ninth subframes of each frame in a plurality of frames;
transmit, to a wireless device, a first measurement subframe allocation bitmap indicating a first plurality of measurement subframes, of a primary carrier, that are not the plurality of Almost Blank Subframes;
transmit, to the wireless device, a second measurement subframe allocation bitmap indicating a second plurality of measurement subframes, of the primary carrier, different from the first plurality of measurement subframes; and
transmit a first Almost Blank Subframe at a power level that is lower than during a subframe that is not an Almost Blank Subframe.
16. The base station of claim 15 , wherein the first Almost Blank Subframe consists essentially of a common reference signal in a control region.
17. The base station of claim 15 , wherein the second measurement subframe allocation bitmap excludes the plurality of Almost Blank Subframes.
18. The base station of claim 15 , wherein the base station periodically receives, from the wireless device, channel state information for one or both of:
one or more subframes indicated in the first measurement subframe allocation bitmap; or
one or more subframes indicated in the second measurement subframe allocation bitmap.
19. The base station of claim 15 , wherein the instructions, when executed by the one or more processors, further cause the base station to:
transmit, based on a decrease in traffic load of the base station by an amount greater than a first value, a third message comprising a second subframe allocation bitmap indicating a second plurality of Almost Blank Subframes, wherein the second plurality of Almost Blank Subframes consists of second, fourth, seventh, and ninth subframes of each frame in a second plurality of frames.
20. The base station of claim 15 , wherein the instructions, when executed by the one or more processors, further cause the base station to:
transmit, based on an increase in traffic load of the base station by an amount greater than a first value, a third message comprising a second subframe allocation bitmap indicating a second plurality of Almost Blank Subframes, wherein the second plurality of Almost Blank Subframes consists of third and eighth subframes of each frame in a second plurality of frames.
21. A method comprising:
transmitting, by a base station, a first message comprising a subframe allocation bitmap indicating a plurality of Almost Blank Subframes, wherein the plurality of Almost Blank Subframes consists of second, fourth, seventh, and ninth subframes of each frame in a plurality of frames;
transmitting, to a wireless device, a first measurement subframe allocation bitmap indicating a first plurality of measurement subframes, of a primary carrier, that are not the plurality of Almost Blank Subframes;
transmitting, to the wireless device, a second measurement subframe allocation bitmap indicating a second plurality of measurement subframes, of the primary carrier, different from the first plurality of measurement subframes; and
transmitting a first Almost Blank Subframe at a power level that is lower than during a subframe that is not an Almost Blank Subframe.
22. The method of claim 21 , wherein the first Almost Blank Subframe consists essentially of a common reference signal in a control region.
23. The method of claim 21 , wherein the second measurement subframe allocation bitmap excludes the plurality of Almost Blank Subframes.
24. The method of claim 21 , wherein the base station periodically receives, from the wireless device, channel state information for one or both of:
one or more subframes indicated in the first measurement subframe allocation bitmap; or
one or more subframes indicated in the second measurement subframe allocation bitmap.
25. A method comprising:
transmitting, by a base station, a first message comprising a subframe allocation bitmap indicating a plurality of Almost Blank Subframes, wherein the plurality of Almost Blank Subframes consists of third and eighth subframes of each frame in a plurality of frames;
transmitting, to a wireless device, a first measurement subframe allocation bitmap indicating a first plurality of measurement subframes, of a primary carrier, that are not the plurality of Almost Blank Subframes;
transmitting, to the wireless device, a second measurement subframe allocation bitmap indicating a second plurality of measurement subframes, of the primary carrier, different from the first plurality of measurement subframes; and
transmitting a first Almost Blank Subframe at a power level that is lower than during a subframe that is not an Almost Blank Subframe.
26. The method of claim 25 , wherein the first Almost Blank Subframe consists essentially of a common reference signal in a control region.
27. The method of claim 25 , wherein the second measurement subframe allocation bitmap excludes the plurality of Almost Blank Subframes.
28. The method of claim 25 , wherein the base station periodically receives, from the wireless device, channel state information for one or both of:
one or more subframes indicated in the first measurement subframe allocation bitmap; or
one or more subframes indicated in the second measurement subframe allocation bitmap.
29. A method comprising:
transmitting, by a base station, a first message comprising a subframe allocation bitmap indicating a plurality of Almost Blank Subframes, wherein the plurality of Almost Blank Subframes consists of second, fourth, and eighth subframes of each frame in a plurality of frames;
transmitting, to a wireless device, a first measurement subframe allocation bitmap indicating a first plurality of measurement subframes, of a primary carrier, that are not the plurality of Almost Blank Subframes;
transmitting, to the wireless device, a second measurement subframe allocation bitmap indicating a second plurality of measurement subframes, of the primary carrier, different from the first plurality of measurement subframes; and
transmitting a first Almost Blank Subframe at a power level that is lower than during a subframe that is not an Almost Blank Subframe.
30. The method of claim 29 , wherein the first Almost Blank Subframe consists essentially of a common reference signal in a control region.
31. The method of claim 29 , wherein the second measurement subframe allocation bitmap excludes the plurality of Almost Blank Subframes.
32. The method of claim 29 , wherein the base station periodically receives, from the wireless device, channel state information for:
one or more subframes indicated in the first measurement subframe allocation bitmap; or
one or more subframes indicated in the second measurement subframe allocation bitmap.
33. The method of claim 29 , further comprising:
transmitting, based on a decrease in traffic load by an amount greater than a first value, a third message comprising a second subframe allocation bitmap indicating a second plurality of Almost Blank Subframes, wherein the second plurality of Almost Blank Subframes consists of second, fourth, seventh, and ninth subframes of each frame in a second plurality of frames.
34. The method of claim 29 , further comprising:
transmitting, based on an increase in traffic load by an amount greater than a first value, a third message comprising a second subframe allocation bitmap indicating a second plurality of Almost Blank Subframes, wherein the second plurality of Almost Blank Subframes consists of third and eighth subframes of each frame in a second plurality of frames.
35. A method comprising:
transmitting, by a base station, a first message comprising a subframe allocation bitmap indicating a plurality of Almost Blank Subframes, wherein the plurality of Almost Blank Subframes consists of third, seventh, and ninth subframes of each frame in a plurality of frames;
transmitting, to a wireless device, a first measurement subframe allocation bitmap indicating a first plurality of measurement subframes, of a primary carrier, that are not the plurality of Almost Blank Subframes;
transmitting, to the wireless device, a second measurement subframe allocation bitmap indicating a second plurality of measurement subframes, of the primary carrier, different from the first plurality of measurement subframes; and
transmitting a first Almost Blank Subframe at a power level that is lower than during a subframe that is not an Almost Blank Subframe.
36. The method of claim 35 , wherein the first Almost Blank Subframe consists essentially of a common reference signal in a control region.
37. The method of claim 35 , wherein the second measurement subframe allocation bitmap excludes the plurality of Almost Blank Subframes.
38. The method of claim 35 , wherein the base station periodically receives, from the wireless device, channel state information for one or both of:
one or more subframes indicated in the first measurement subframe allocation bitmap; or
one or more subframes indicated in the second measurement subframe allocation bitmap.
39. The method of claim 35 , further comprising:
transmitting, based on a decrease in traffic load of the base station by an amount greater than a first value, a third message comprising a second subframe allocation bitmap indicating a second plurality of Almost Blank Subframes, wherein the second plurality of Almost Blank Subframes consists of second, fourth, seventh, and ninth subframes of each frame in a second plurality of frames.
40. The method of claim 35 , further comprising:
transmitting, based on an increase in traffic load of the base station by an amount greater than a first value, a third message comprising a second subframe allocation bitmap indicating a second plurality of Almost Blank Subframes, wherein the second plurality of Almost Blank Subframes consists of third and eighth subframes of each frame in a second plurality of frames.