Secondary cell activation and deactivation enhancements in new radio
Methods, systems, and devices for wireless communications are described. One method may include transmitting a first signal instructing a user equipment (UE) to transition a state of a secondary cell associated with the UE; determining an allocation of resources for the UE to communicate with the secondary cell; and transmitting a second signal including an indication of an active bandwidth part (BWP) used for the allocation of resources based on the determining. The active BWP and the first signal may indicate the transition of the state of the secondary cell.
1. A method for wireless communications, comprising:
configuring a state of a secondary cell associated with a group of secondary cells to be in a dormant state based at least in part on an active bandwidth part comprising a zero bandwidth part;
configuring in a message a bitmap comprising an indication of the state of the secondary cell; and
transmitting the message including the bitmap comprising the indication of the state of the secondary cell.
2. The method of claim 1 , wherein
a physical downlink control channel (PDCCH) on the zero bandwidth part is not monitored when the secondary cell is in the dormant state.
3. The method of claim 1 , wherein configuring the state of the secondary cell associated with the group of secondary cells comprises:
configuring the secondary cell associated with the group of secondary cells to switch to a fully activated state from the dormant state based at least in part on a second indication in the message.
4. The method of claim 1 , wherein configuring the state of the secondary cell associated with the group of secondary cells comprises:
configuring the secondary cell associated with the group of secondary cells to be in a fully activated state based at least in part on the active bandwidth part comprising a non-zero bandwidth part.
5. The method of claim 1 , further comprising:
transmitting, via the secondary cell, a second indication in the message to switch the secondary cell to the zero bandwidth part.
6. The method of claim 5 , wherein the second indication comprises a carrier indicator field.
7. The method of claim 1 , wherein configuring the state of the secondary cell associated with the group of secondary cells comprises:
configuring the secondary cell associated with the group of secondary cells to switch to a default bandwidth part comprising a zero-bandwidth part based at least in part on a bandwidth timer expiring.
8. The method of claim 1 , further comprising:
transmitting, via downlink control signaling, the message including the bitmap comprising the indication of the state of the secondary cell associated with the group of secondary cells,
wherein the message comprises a downlink control information message.
9. The method of claim 1 , further comprising:
transmitting, via higher layer signaling, the message including the bitmap comprising the indication of the state of the secondary cell associated with the group of secondary cells,
wherein the higher layer signaling comprises radio resource control signaling or medium access control-control element signaling.
10. The method of claim 1 , further comprising:
identifying a set of bits associated with the bitmap in the message, the bitmap comprising the set of bits to indicate states of secondary cells associated with the group of secondary cells,
wherein a presence of the bitmap in the message is determined based at least in part on a zero-resource assignment or a dummy grant for resource allocation.
11. The method of claim 10 , further comprising:
receiving a feedback message comprising an indication of a decoding result of the transmitted message, wherein the feedback message comprises an acknowledgement message or a non-acknowledgement message.
12. The method of claim 1 , wherein the message comprises a downlink control information message corresponding to a downlink control information format comprising a bandwidth part identifier indicating a target bandwidth part identifier associated with a primary cell and a number of fields for a downlink grant, wherein at least one field of the number of fields comprises the bitmap indicating the state of the secondary cell associated with the group of secondary cells.
13. The method of claim 1 , wherein the message comprises bandwidth part activation control information for the secondary cell associated with the group of secondary cells.
14. The method of claim 1 , further comprising:
receiving from a user equipment (UE) for the zero bandwidth part when the secondary cell is in the dormant state: a radio resource management (RRM) measurement, a channel state information (CSI) measurement, a sounding reference signal (SRS), a power headroom reporting (PHR) measurement, or communications for a contention-based Random Access Channel (RACH) procedure, or a combination thereof.
15. The method of claim 1 , wherein the message comprises a bandwidth part downlink control information message.
16. A method for wireless communications, comprising:
receiving a message including a bitmap comprising an indication of a state of a secondary cell associated with a group of secondary cells;
identifying a configuration of the state of the secondary cell based at least in part on the indication in the received message; and
switching the state of the secondary cell to be in a dormant state based at least in part on the identifying and on an active bandwidth part comprising a zero bandwidth part.
17. The method of claim 16 , further comprising:
refraining from monitoring a physical downlink control channel (PDCCH) on the zero bandwidth part when the secondary cell is in the dormant state.
18. The method of claim 16 , wherein switching the state of the secondary cell comprise:
switching the state of the secondary cell associated with the group of secondary cells to a fully activated state based at least in part on an active bandwidth part comprising a non-zero bandwidth part,
wherein the fully activated state comprises a non-dormant state.
19. The method of claim 16 , further comprising:
receiving, via the secondary cell, a second indication in the message to switch the secondary cell to the zero bandwidth part, the second indication comprising a carrier indicator field, wherein switching the state of the secondary cell comprises:
switching the state of the secondary cell associated with the group of secondary cells to a fully activated state from a partially activated state based at least in part on the second indication.
20. The method of claim 16 , wherein receiving the message comprises:
receiving, via downlink control signaling, the message including the bitmap comprising the indication of the state of the secondary cell associated with the group of secondary cells,
wherein the message comprises a downlink control information message.
21. The method of claim 16 , wherein receiving the message comprises:
receiving, via higher layer signaling, the message including the bitmap comprising the indication of the state of the secondary cell associated with the group of secondary cells,
wherein the higher layer signaling comprises radio resource control signaling or medium access control-control element signaling.
22. The method of claim 16 , further comprising:
determining a presence of the bitmap in the received message based at least in part on a zero-resource assignment or a dummy grant for resource allocation; and
identifying a set of bits associated with the bitmap in the message, the bitmap comprising the set of bits to indicate states of secondary cells associated with the group of secondary cells.
23. The method of claim 16 , further comprising:
determining that the state of the secondary cell is in the dormant state; and
refraining from monitoring a control channel on the secondary cell based at least in part on the state of the secondary cell being in the dormant state, wherein the control channel comprises a physical downlink control channel.
24. The method of claim 16 , further comprising:
transmitting a feedback message comprising an indication of a decoding result of the received message, wherein the feedback message comprises an acknowledgement message or a non-acknowledgement message.
25. The method of claim 16 , wherein the message comprises a downlink control information message corresponding to a downlink control information format comprising a bandwidth part identifier indicating a target bandwidth part identifier associated with a primary cell and a number of fields for a downlink grant, wherein at least one field of the number of fields comprises the bitmap indicating the state of the secondary cell associated with the group of secondary cells.
26. The method of claim 16 , wherein the message comprises bandwidth part activation control information for the secondary cell associated with the group of secondary cells.
27. The method of claim 16 , further comprising:
performing, for the zero bandwidth part when the secondary cell is in the dormant state, one or more of: a radio resource management (RRM) measurement, a channel state information (CSI) measurement, a sounding reference signal (SRS) transmission, a power headroom reporting (PHR) measurement, and communications for a contention-based Random Access Channel (RACH) procedure.
28. The method of claim 16 , wherein the message comprises a bandwidth part downlink control information message.
29. An apparatus for wireless communications, comprising:
a processor,
memory coupled with the processor; and
instructions stored in the memory and executable by the processor to cause the apparatus to:
configure a state of a secondary cell associated with a group of secondary cells to be in a dormant state based at least in part on an active bandwidth part comprising a zero bandwidth part;
configure in a message a bitmap comprising an indication of the state of the secondary cell; and
transmit the message including the bitmap comprising the indication of the state of the secondary cell.
30. An apparatus for wireless communications, comprising:
a processor,
memory coupled with the processor; and
instructions stored in the memory and executable by the processor to cause the apparatus to:
receive a message including a bitmap comprising an indication of a state of a secondary cell associated with a group of secondary cells;
identify a configuration of the state of the secondary cell based at least in part on the indication in the received message; and
switch the state of the secondary cell to be in a dormant state based at least in part on the identifying and on an active bandwidth part comprising a zero bandwidth part.