Carrier Indicator Field Usage and Configuration in Carrier Aggregation

• US 20120076088A1
• Filed: 09/28/2011
• Published: 03/29/2012
• Est. Priority Date: 09/28/2010
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Hwang, Woonhee, Koskela, Jarkko, Malkamaki, Esa
• Granted Patent: US 8,902,770 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

Format of a downlink control channel for a user equipment UE is changed in conjunction with switching the UE between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling. The changed format is used on at least one serving cell of the UE'"'"'s configured set of component carriers CCs. In one embodiment the changed format comprises an explicit carrier indicator field CIF for the case in which the switching is from disabled to enabled; and the changed format has no explicit CIF when the switching is from enabled to disabled. In another embodiment switching from disabled to enabled comprises the UE'"'"'s configured set of CCs being changed from one to multiple cells; and switching from enabled to disabled comprises the UE'"'"'s configured set of CCs being changed from multiple cells to one cell. In one embodiment the changed format is implicit.

Claims

1. A method, comprising:

changing format of a downlink control channel for a user equipment in conjunction with switching the user equipment between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling; and

thereafter using the changed format of the downlink control channel at least on one serving cell of the user equipment'"'"'s configured set of component carriers.

2. The method according to claim 1, in which:

the changed format comprises an explicit carrier indicator field for the case in which the switching is from disabled for cross carrier scheduling to enabled for cross carrier scheduling; and

the changed format comprises a format which has no explicit carrier indicator field for the case in which the switching is from enabled for cross carrier scheduling to disabled for cross carrier scheduling.

3. The method according to claim 1, in which switching between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling comprises:

the user equipment'"'"'s configured set of component carriers is changed from only a primary cell to multiple cells for the case in which the switching is from disabled for cross carrier scheduling to enabled for cross carrier scheduling; and

the user equipment'"'"'s configured set of component carriers is changed from multiple cells to only a primary cell for the case in which the switching is from enabled for cross carrier scheduling to disabled for cross carrier scheduling.

4. The method according to claim 1, in which changing the format of the downlink control channel is implicit based on the switch between the user equipment being enabled for cross carrier scheduling and being disabled for cross carrier scheduling.

5. The method according to claim 1, in which changing the format of the downlink control channel is based on explicit signaling between a network and the user equipment.

6. The method according to claim 5, in which for the case where the user equipment is switched from being disabled for cross carrier scheduling to being enabled for cross carrier scheduling, the changed format is indicated on each cell of the user equipment'"'"'s configured set of component carriers.

7. The method according to claim 1, in which the method is executed by a network access node which switches the user equipment between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling by sending to the user equipment a Connection Reconfiguration message;

and wherein using the changed format of the downlink control channel on the user equipment'"'"'s configured set of component carriers comprises transmitting the downlink control channel in the changed format on at least one serving cell of the user equipment'"'"'s configured set of component carriers.

8. The method according to claim 1, in which the method is executed by the user equipment which switches between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling by adding or removing a component carrier from its configured set according to a Connection Reconfiguration message received from a network;

and wherein using the changed format of the downlink control channel on the user equipment'"'"'s configured set of component carriers comprises decoding the downlink control channel using only the change format on at least one serving cell of the user equipment'"'"'s configured set of component carriers.

9. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform;

changing format of a downlink control channel for a user equipment in conjunction with switching the user equipment between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling; and

thereafter using the changed format of the downlink control channel on at least one serving cell of the user equipment'"'"'s configured set of component carriers.

10. The apparatus according to claim 9, in which:

the changed format comprises an explicit carrier indicator field for the case in which the switching is from disabled for cross carrier scheduling to enabled for cross carrier scheduling; and

the changed format comprises a format which has no explicit carrier indicator field for the case in which the switching is from enabled for cross carrier scheduling to disabled for cross carrier scheduling.

11. The apparatus according to claim 9, in which switching between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling comprises:

the user equipment'"'"'s configured set of component carriers is changed from only a primary cell to multiple cells for the case in which the switching is from disabled for cross carrier scheduling to enabled for cross carrier scheduling; and

the user equipment'"'"'s configured set of component carriers is changed from multiple cells to only a primary cell for the case in which the switching is from enabled for cross carrier scheduling to disabled for cross carrier scheduling.

12. The apparatus according to claim 9, in which changing the format of the downlink control channel is implicit based on the switch between the user equipment being enabled for cross carrier scheduling and being disabled for cross carrier scheduling.

13. The apparatus according to claim 9, in which changing the format of the downlink control channel is based on explicit signaling between a network and the user equipment.

14. The apparatus according to claim 13, in which for the case where the user equipment is switched from being disabled for cross carrier scheduling to being enabled for cross carrier scheduling, the changed format is indicated on each cell of the user equipment'"'"'s configured set of component carriers.

15. The apparatus according to claim 9, in which the apparatus comprises a network access node which switches the user equipment between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling by sending to the user equipment a Connection Reconfiguration message;

and wherein using the changed format of the downlink control channel on the user equipment'"'"'s configured set of component carriers comprises transmitting the downlink control channel in the changed format on at least one serving cell of the user equipment'"'"'s configured set of component carriers.

16. The apparatus according to claim 9, in which the apparatus comprises the user equipment which switches between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling by adding or removing a component carrier from its configured set according to a Connection Reconfiguration message received from a network;

and wherein using the changed format of the downlink control channel on the user equipment'"'"'s configured set of component carriers comprises decoding the downlink control channel using only the changed format on at least one serving cell of the user equipment'"'"'s configured set of component carriers.

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

changing format of a downlink control channel for a user equipment in conjunction with switching the user equipment between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling; and

thereafter using the changed format of the downlink control channel on at least one serving cell of the user equipment'"'"'s configured set of component carriers.

18. The computer readable memory according to claim 17, in which:

the changed format comprises an explicit carrier indicator field for the case in which the switching is from disabled for cross carrier scheduling to enabled for cross carrier scheduling; and

the changed format comprises a format which has no explicit carrier indicator field for the case in which the switching is from enabled for cross carrier scheduling to disabled for cross carrier scheduling.

19. The computer readable memory according to claim 17, in which switching between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling comprises:

the user equipment'"'"'s configured set of component carriers is changed from only a primary cell to multiple cells for the case in which the switching is from disabled for cross carrier scheduling to enabled for cross carrier scheduling; and

the user equipment'"'"'s configured set of component carriers is changed from multiple cells to only a primary cell for the case in which the switching is from enabled for cross carrier scheduling to disabled for cross carrier scheduling.

20. The computer readable memory according to claim 17, in which changing the format of the downlink control channel is implicit based on the switch between the user equipment being enabled for cross carrier scheduling and being disabled for cross carrier scheduling.

21. A method, comprising:

changing format of a downlink control channel for a user equipment from a format which has no explicit carrier indicator field to a format that which has an explicit carrier indicator field; and

thereafter

switching the user equipment from being disabled for cross carrier scheduling to being enabled for cross carrier scheduling.

22. The method according to claim 21, in which changing the format of the downlink control channel is based on explicit signaling between a network and the user equipment.

23. The method according to claim 21, in which switching the user equipment from being disabled for cross carrier scheduling to being enabled for cross carrier scheduling comprises:

changing the user equipment'"'"'s configured set of component carriers from only a primary cell to multiple cells configured to use cross carrier scheduling.

24. The method according to claim 21, in which switching the user equipment from being disabled for cross carrier scheduling to being enabled for cross carrier scheduling comprises:

adding to the user equipment'"'"'s configured set of component carriers a secondary cell configured to use cross carrier scheduling.

25. The method according to claim 24, in which changing the format of the downlink control channel is based on explicit signaling between a network and the user equipment.