Cross-scheduling for random access response

• US 20120287865A1
• Filed: 05/11/2011
• Published: 11/15/2012
• Est. Priority Date: 05/11/2011
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Wu, Chunli, Sebire, Benoist Pierre
• Granted Patent: US 9,642,161 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

In a random access procedure, a downlink random access response indicates at least a timing advance and an explicit indication identifying one component carrier or cell (CC/Cell) of a plurality of component carriers or cells, or a group of CCs/Cells, to which the timing advance applies. The eNB or UE then operate their radio on the indicated one CC/Cell synchronous with the timing advance. In various embodiments the random access response may also indicate an uplink resource granted to the user equipment, which lies on that same one or group of CCs/Cells. The explicit indication may be a single bit indicating a timing advance group; a CC/Cell/group index whose presence in the response is indicated by a flag bit; a CC/Cell/group index in the response is known from the response'"'"'s format whether it includes such an index, where the format indication can be via a bit in the response itself or RRC signaling or implicit from the RACH and cross-carrier scheduling being configured.

Claims

1. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

in which the at least one memory and the computer program code are configured with the at least one processor to cause the apparatus at least to;

perform a random access procedure in which a downlink random access response from a network node to a user equipment indicates a timing advance and an explicit indication identifying one component carrier or cell of a plurality of component carriers or cells, or a group of component carriers or cells, to which the timing advance applies; and

thereafter

operate a wireless radio on the indicated one or group of component carriers or cells synchronous with the timing advance.

2. The apparatus according to claim 1, in which

the downlink random access response further indicates an uplink resource granted to the user equipment, and

the at least one memory and the computer program code are configured with the at least one processor to cause the apparatus to operate the wireless radio to send or receive using the uplink resource on the indicated one or group of component carriers or cells to which the timing advance is applied.

3. The apparatus according to claim 2, in which the random access response indicates by an index the one component carrier or cell the uplink resource is on.

4. The apparatus according to claim 1, in which

the random access response identifies the group of component carriers or cells by a single bit indicating a timing advance group,

in which the timing advance applies to all component carriers or cells within the group.

5. The apparatus according to claim 1, in which the random access response identifies the one or group of component carriers or cells by an index, and the random access response further comprises a flag bit which indicates that the index is included in the random access response.

6. The apparatus according to claim 1, in which the random access response identifies the one or group of component carriers or cells by an index and a format of whether the random access response includes the index is identified by one of:

radio resource signaling between the network node and the user equipment; and

implicitly from a random access channel and cross carrier scheduling being configured.

7. The apparatus according to claim 1, in which the apparatus comprises the network node or one or more components therefore.

8. The apparatus according to claim 7, in which the random access response comprises a first random access response and the at least one memory and the computer program code are configured with the at least one processor to cause the apparatus at least further to:

schedule the first and other random access responses on a primary component carrier or primary cell of the plurality of component carriers or cells, regardless of which one or group of component carriers or cells the timing advance of the first and other random access responses applies.

9. The apparatus according to claim 7, in which the random access response comprises a first random access response and the at least one memory and the computer program code are configured with the at least one processor to cause the apparatus at least further to:

send to the user equipment and to other user equipments a medium access control protocol data unit comprising a plurality of random access responses, in which the first random access response is disposed within the protocol data unit following all other random access responses which lack an explicit indication identifying the one or group of component carriers or cells to which their respective timing advance applies.

10. The apparatus according to claim 1, in which the apparatus comprises the user equipment or one or more components therefore.

11. A method, comprising:

performing a random access procedure in which a downlink random access response from a network node to a user equipment indicates at least a timing advance, and an explicit indication identifying one component carrier or cell of a plurality of component carriers or cells, or a group of component carriers or cells, to which the timing advance applies; and

thereafter

operating a wireless radio on the indicated one or group of component carriers or cells synchronous with the timing advance.

12. The method according to claim 11, in which:

the downlink random access response further indicates an uplink resource granted to the user equipment, and

operating the wireless radio comprises sending or receiving using the uplink resource on the indicated one or group of component carriers or cells to which the timing advance is applied.

13. The method according to claim 12, in which the random access response indicates by an index the one component carrier or cell the uplink resource is on.

14. The method according to claim 11, in which the random access response identifies the group of component carriers or cells by a single bit indicating a timing advance group;

in which the timing advance applies to all component carriers or cells within the group.

15. The method according to claim 11, in which the random access response identifies the one or group of component carriers or cells by an index, and the random access response further comprises a flag bit which indicates that the index is included in the random access response.

16. The method according to claim 11, in which the random access response identifies the one or group of component carriers or cells by an index and a format of whether the random access response includes the index is identified by one of:

radio resource signaling between the network node and the user equipment; and

implicitly from a random access channel and cross carrier scheduling being configured.

17. The method according to claim 11, executed by the network node or one or more components therefore, and in which the random access response comprises a first random access response;

the method further comprising;

scheduling the first and other random access responses on a primary component carrier or primary cell of the plurality of component carriers or cells, regardless of which one or group of component carriers or cells the timing advance of the first and other random access responses applies.

18. The method according claim 11, executed by the network node or one or more components therefore, and in which the random access response comprises a first random access response;

the method further comprising;

sending to the user equipment and to other user equipments a medium access control protocol data unit comprising a plurality of random access responses, in which the first random access response is disposed within the protocol data unit following all other random access responses which lack an explicit indication identifying the one or group of component carriers or cells to which their respective timing advance applies.

19. The method according to claim 11, in which the user equipment is explicitly configured by the network node for a format of the downlink random access response via radio resource control signaling.

20. A computer readable memory storing a program of computer readable instructions that when executed by a processor result in actions comprising:

performing a random access procedure in which a downlink random access response from a network node to a user equipment indicates at least a timing advance, and an explicit indication identifying one component carrier or cell of a plurality of component carriers or cells, or a group of component carriers or cells, to which the timing advance applies; and

thereafter

operating a wireless radio on the indicated one or group of component carriers or cells synchronous with the timing advance.

21. (canceled)