Carrier indicator field usage and configuration in carrier aggregation
View Patent ↗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.
1. A computer-implemented method controlled by a programmed computer or data processor, said 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, in which changing the format of the downlink control channel is based on explicit signaling between a network and the user equipment; 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 computer-implemented 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 computer-implemented 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 computer-implemented 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 computer-implemented method according to claim 1 , 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.
6. The computer-implemented 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.
7. The computer-implemented 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 changed format on at least one serving cell of the user equipment's configured set of component carriers.
8. The computer-implemented method according to claim 1 , wherein 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;
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.
9. The computer-implemented 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;
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.
10. 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, with the at least one processor, to enable 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, in which changing the format of the downlink control channel is based on explicit signaling between a network and the user equipment; 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.
11. The apparatus according to claim 10 , 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.
12. The apparatus according to claim 10 , 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.
13. The apparatus according to claim 10 , 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.
14. The apparatus according to claim 10 , 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 10 , 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 10 , 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. The apparatus according to claim 10 , wherein 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;
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.
18. The apparatus according to claim 10 , wherein the apparatus comprises the user equipment which switches between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling;
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.
19. A non-transitory computer readable medium 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, in which changing the format of the downlink control channel is based on explicit signaling between a network and the user equipment; 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.
20. The non-transitory computer readable medium according to claim 19 , 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.
21. The non-transitory computer readable medium according to claim 19 , 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.
22. The non-transitory computer readable medium according to claim 19 , 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.
23. The non-transitory computer readable medium storing a program of computer readable instructions according to claim 19 that when executed by a processor in a network access node result in actions comprising:
switching the user equipment between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling;
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.
24. The non-transitory computer readable medium storing a program of computer readable instructions according to claim 19 that when executed by a processor in a user equipment result in actions comprising:
switching between being enabled for cross carrier scheduling and being disabled for cross carrier scheduling;
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.