Random access mechanism for a wireless device and base station
Wireless communications are described. Cells may be grouped into a plurality of cell groups, wherein each cell group of the plurality of cell groups may comprise a downlink-uplink cell assigned to the cell group. A wireless device may transmit an uplink signal via a downlink-uplink cell based on a timing advance command.
1. A wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the wireless device to:
receive a timing advance command for a first cell group of a plurality of cell groups, wherein each cell group of the plurality of cell groups comprises a downlink-uplink cell, and wherein each of a plurality of downlink-only cells is assigned to a cell group of the plurality of cell groups; and
transmit an uplink signal via a downlink-uplink cell of the first cell group, wherein timing of the uplink signal is based on the timing advance command.
2. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, cause the wireless device to receive a time alignment timer parameter for each cell group of the plurality of cell groups.
3. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to receive a control command configured to cause a transmission of a random access preamble via random access resources of a first secondary cell of a secondary cell group of the plurality of cell groups.
4. The wireless device of claim 1 , wherein:
the plurality of cell groups comprises a primary cell group and a secondary cell group;
uplink signals, transmitted by the wireless device via the primary cell group, use a first synchronization signal, transmitted via a primary cell, as a first timing reference; and
uplink signals, transmitted by the wireless device via the secondary cell group, use a second synchronization signal, transmitted via one of at least one activated cell of the secondary cell group, as a second timing reference.
5. The wireless device of claim 1 , wherein the timing advance command is configured to cause alignment of reception timing of uplink signals at a base station, and wherein the instructions, when executed by the one or more processors, further cause the wireless device to transmit the uplink signals in frames and subframes of one or more activated downlink-uplink cells of the first cell group.
6. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to start or restart a first time alignment timer corresponding to the first cell group based on the wireless device receiving the timing advance command.
7. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to determine that the first cell group is:
out-of-sync, if a first time alignment timer has expired or is not running; and
in-sync, if the first time alignment timer is running.
8. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, cause the wireless device to receive a plurality of radio dedicated parameters for each one of a plurality of secondary cells, and wherein one secondary cell is assigned to:
a secondary cell group indicated by a cell group index, if the plurality of radio dedicated parameters comprises the cell group index for the one secondary cell; or
a primary cell group.
9. The wireless device of claim 1 , wherein each downlink-only cell of the plurality of downlink-only cells is assigned to a cell group, of the plurality of cell groups, comprising a downlink-uplink cell in a same frequency band as the each downlink-only cell of the plurality of downlink-only cells.
10. 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 timing advance command for a first cell group of a plurality of cell groups, wherein each cell group of the plurality of cell groups comprises a downlink-uplink cell, and wherein each of a plurality of downlink-only cells is assigned to a cell group of the plurality of cell groups; and
receive an uplink signal via a downlink-uplink cell of the first cell group, wherein timing of the uplink signal is based on the timing advance command.
11. The base station of claim 10 , wherein the instructions, when executed by the one or more processors, further cause the base station to transmit a time alignment timer parameter for each cell group of the plurality of cell groups.
12. The base station of claim 10 , wherein the instructions, when executed by the one or more processors, further cause the base station to transmit a control command configured to cause a transmission of a random access preamble via random access resources of a first secondary cell of a secondary cell group of the plurality of cell groups.
13. The base station of claim 10 , wherein the timing advance command is configured to cause alignment of reception timing of uplink signals at the base station, and wherein the instructions, when executed by the one or more processors, further cause the base station to receive the uplink signals in frames and subframes of one or more activated downlink-uplink cells of the first cell group.
14. The base station of claim 10 , wherein the timing advance command is configured to cause a wireless device to start or restart a first time alignment timer corresponding to the first cell group.
15. The base station of claim 10 , wherein the instructions, when executed by the one or more processors, cause the base station to transmit a plurality of radio dedicated parameters for each one of a plurality of secondary cells, and wherein one secondary cell is assigned to:
a secondary cell group indicated by a cell group index, if the plurality of radio dedicated parameters comprises the cell group index for the one secondary cell; or
a primary cell group.
16. The base station of claim 10 , wherein each downlink-only cell of the plurality of downlink-only cells is assigned to a cell group, of the plurality of cell groups, comprising a downlink-uplink cell in a same frequency band as the each downlink-only cell of the plurality of downlink-only cells.
17. A system comprising:
a base station comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors of the base station, cause the base station to:
transmit a timing advance command for a first cell group of a plurality of cell groups, wherein each cell group of the plurality of cell groups comprises a downlink-uplink cell, and wherein each of a plurality of downlink-only cells is assigned to a cell group of the plurality of cell groups; and
a wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors of the wireless device, cause the wireless device to:
transmit an uplink signal via a downlink-uplink cell of the first cell group, wherein timing of the uplink signal is based on the timing advance command.
18. The system of claim 17 , wherein the instructions stored in the memory of the base station, when executed by the one or more processors of the base station, further cause the base station to transmit a time alignment timer parameter for each cell group of the plurality of cell groups.
19. The system of claim 17 , wherein the instructions stored in the memory of the base station, when executed by the one or more processors of the base station, further cause the base station to transmit a control command configured to cause a transmission of a random access preamble via random access resources of a first secondary cell of a secondary cell group of the plurality of cell groups.
20. The system of claim 17 , wherein:
the plurality of cell groups comprises a primary cell group and a secondary cell group;
uplink signals, transmitted by the wireless device via the primary cell group, use a first synchronization signal, transmitted via a primary cell, as a first timing reference; and
uplink signals, transmitted by the wireless device via the secondary cell group, use a second synchronization signal, transmitted via one of at least one activated cell of the secondary cell group, as a second timing reference.
21. The system of claim 17 , wherein the timing advance command is configured to cause alignment of reception timing of uplink signals at the base station, and wherein the instructions stored in the memory of the wireless device, when executed by the one or more processors of the wireless device, further cause the wireless device to transmit the uplink signals in frames and subframes of one or more activated downlink-uplink cells of the first cell group.
22. The system of claim 17 , wherein the timing advance command is configured to cause the wireless device to start or restart a first time alignment timer corresponding to the first cell group.
23. The system of claim 17 , wherein the instructions stored in the memory of the wireless device, when executed by the one or more processors of the wireless device, further cause the wireless device to determine that the first cell group is:
out-of-sync, if a first time alignment timer has expired or is not running; and
in-sync, if the first time alignment timer is running.
24. The system of claim 17 , wherein the instructions stored in the memory of the base station, when executed by the one or more processors of the base station, cause the base station to transmit a plurality of radio dedicated parameters for each one of a plurality of secondary cells, and wherein one secondary cell is assigned to:
a secondary cell group indicated by a cell group index, if the plurality of radio dedicated parameters comprises the cell group index for the one secondary cell; or
a primary cell group.
25. The system of claim 17 , wherein each downlink-only cell of the plurality of downlink-only cells is assigned to a cell group, of the plurality of cell groups, comprising a downlink-uplink cell in a same frequency band as the each downlink-only cell of the plurality of downlink-only cells.
26. A method comprising:
receiving, by a wireless device, a timing advance command for a first cell group of a plurality of cell groups, wherein each cell group of the plurality of cell groups comprises a downlink-uplink cell, and wherein each of a plurality of downlink-only cells is assigned to a cell group of the plurality of cell groups; and
transmitting an uplink signal via a downlink-uplink cell of the first cell group, wherein timing of the uplink signal is based on the timing advance command.
27. The method of claim 26 , further comprising:
receiving a time alignment timer parameter for each cell group of the plurality of cell groups.
28. The method of claim 26 , further comprising:
receiving a control command configured to cause a transmission of a random access preamble via random access resources of a first secondary cell of a secondary cell group of the plurality of cell groups.
29. The method of claim 26 , wherein the plurality of cell groups comprises a primary cell group and a secondary cell group, and wherein the method further comprises:
transmitting, via the primary cell group, first uplink signals, wherein the transmitting the first uplink signals comprising using a first synchronization signal, transmitted via a primary cell, as a first timing reference; and
transmitting, via the secondary cell group, second uplink signals, wherein the transmitting the second uplink signals comprises using a second synchronization signal, transmitted via one of at least one activated cell of the secondary cell group, as a second timing reference.
30. The method of claim 26 , wherein the timing advance command is configured to cause alignment of reception timing of uplink signals at a base station, and wherein the method further comprises transmitting the uplink signals in frames and subframes of one or more activated downlink-uplink cells of the first cell group.
31. The method of claim 26 , further comprising:
based on the wireless device receiving the timing advance command, starting or restarting a first time alignment timer corresponding to the first cell group.
32. The method of claim 26 , further comprising determining that the first cell group is:
out-of-sync, if a first time alignment timer has expired or is not running; and
in-sync, if the first time alignment timer is running.
33. The method of claim 26 , further comprising:
receiving a plurality of radio dedicated parameters for each one of a plurality of secondary cells, wherein one secondary cell is assigned to:
a secondary cell group indicated by a cell group index, if the plurality of radio dedicated parameters comprises the cell group index for the one secondary cell; or
a primary cell group.
34. The method of claim 26 , wherein each downlink-only cell of the plurality of downlink-only cells is assigned to a cell group, of the plurality of cell groups, comprising a downlink-uplink cell in a same frequency band as the each downlink-only cell of the plurality of downlink-only cells.
35. A method comprising:
transmitting, by a base station, a timing advance command for a first cell group of a plurality of cell groups, wherein each cell group of the plurality of cell groups comprises a downlink-uplink cell, and wherein each of a plurality of downlink-only cells is assigned to a cell group of the plurality of cell groups; and
receiving an uplink signal via a downlink-uplink cell of the first cell group, wherein timing of the uplink signal is based on the timing advance command.
36. The method of claim 35 , further comprising:
transmitting a time alignment timer parameter for each cell group of the plurality of cell groups.
37. The method of claim 35 , further comprising:
transmitting a control command configured to cause a transmission of a random access preamble via random access resources of a first secondary cell of a secondary cell group of the plurality of cell groups.
38. The method of claim 35 , wherein the timing advance command is configured to cause alignment of reception timing of uplink signals at the base station, and wherein the method further comprises receiving the uplink signals in frames and subframes of one or more activated downlink-uplink cells of the first cell group.
39. The method of claim 35 , wherein the timing advance command is configured to cause a wireless device to start or restart a first time alignment timer corresponding to the first cell group.
40. The method of claim 35 , further comprising:
transmitting a plurality of radio dedicated parameters for each one of a plurality of secondary cells, wherein one secondary cell is assigned to:
a secondary cell group indicated by a cell group index, if the plurality of radio dedicated parameters comprises the cell group index for the one secondary cell; or
a primary cell group.
41. The method of claim 35 , wherein each downlink-only cell of the plurality of downlink-only cells is assigned to a cell group, of the plurality of cell groups, comprising a downlink-uplink cell in a same frequency band as the each downlink-only cell of the plurality of downlink-only cells.