Secondary cell beam failure recovery operation in new radio (NR)

1. A user equipment (UE), comprising:

radio front end circuitry; and

processor circuitry, coupled the radio front end circuitry, configured to:

detect a beam failure on a secondary cell (SCell);

generate a beam failure recovery request (BFRQ) for the SCell, wherein the BFRQ comprises a component carrier identifier for the SCell and a first plurality of candidate beam identifiers for a new beam to be used for recovery;

transmit, using the radio front end circuitry, the BFRQ for the SCell over a primary cell (PCell) to a base station;

receive, from the base station, a response for the BFRQ for the SCell over the SCell or the PCell, wherein the response includes a second plurality of candidate beams; and

select one beam from the second plurality of candidate beams and use as the new beam to receive downlink transmission over the SCell.

2. The UE of claim 1 , wherein to transmit the BFRQ for the SCell, the processor circuitry is further configured to:

transmit, using the radio front end circuitry, the BFRQ for the SCell over a Primary Uplink Control Chanel (PUCCH) or a Physical Random Access Channel (PRACH) over the PCell to the base station.

3. The UE of claim 1 , wherein to transmit the BFRQ for the SCell the processor circuitry is further configured to:

transmit, using the radio front end circuitry, the BFRQ for the SCell over a Primary Uplink Shared Channel (PUSCH) over the PCell to the base station.

4. The UE of claim 1 , wherein to receive the response for the BFRQ for the SCell the processor circuitry is further configured to:

receive, from the base station, the response for the BFRQ for the SCell over a control-resource set (CORESET) over the SCell.

5. The UE of claim 1 , wherein to receive the response for the BFRQ for the SCell the processor circuitry is further configured to:

receive, from the base station, the response for the BFRQ for the SCell over the PCell, wherein the response for the BFRQ for the SCell is a re-activation command.

6. The UE of claim 1 , wherein the BFRQ further comprises a layer 1 reference signal received power (L1-RSRP) for the new beam or a layer 1 signal-to-interference-plus-noise ratio (L1-SINR) for the new beam.

7. The UE of claim 1 , wherein the processor circuitry is further configured to:

determine there is no available Primary Uplink Shared Channel (PUSCH) over the PCell;

transmit, using the radio front end circuitry, a schedule request (SR) for allocating a PUSCH over the PCell to the base station; and

in response to transmitting the SR, receive, from the base station, an indication of an allocated PUSCH over the PCell; and

wherein to transmit the BFRQ for the SCell, the processor circuitry is further configured to:

transmit, using the radio front end circuitry, the BFRQ for the SCell using a media access control control element (MAC-CE) over the allocated PUSCH over the PCell to the base station.

8. The UE of claim 7 , wherein to transmit the SR, the processor circuitry is further configured to:

transmit, using the radio front end circuitry, the SR to the base station N milliseconds after detection of the beam failure on the SCell, wherein N is a configurable non-negative value or a predefined non-negative value.

9. The UE of claim 7 , wherein to transmit the SR the processor circuitry is further configured to:

transmit, using the radio front end circuitry, the BFRQ for the SCell using a buffer status report (BSR) over the allocated PUSCH over the PCell to the base station.

10. A method for performing beam failure recovery, comprising:

detecting a beam failure on a secondary cell (SCell);

generating a beam failure recovery request (BFRQ) for the SCell, wherein the BFRQ comprises a component carrier identifier for the SCell and a first plurality of candidate beam identifiers for a new beam to be used for recovery;

transmitting the BFRQ for the SCell over a primary cell (PCell) to a base station;

receiving, from the base station, a response for the BFRQ for the SCell over the SCell or the PCell, wherein the response includes a second plurality of candidate beams; and

selecting one beam from the second plurality of candidate beams and use as the new beam to receive downlink transmission over the SCell.

11. The method of claim 10 , wherein the transmitting the BFRQ for the SCell further comprises:

transmitting, to the base station, the BFRQ for the SCell over a Primary Uplink Control Channel (PUCCH) or a Physical Random Access Channel (PRACH) over the PCell.

12. The method of claim 10 , wherein the BFRQ further comprises a layer 1 reference signal received power (L1-RSRP) for the new beam or a layer 1 signal-to-interference-plus-noise ratio (L1-SINR) for the new beam.

13. The method of claim 10 , further comprising:

determining there is no available Primary Uplink Shared Channel (PUSCH) over the PCell;

transmitting, to the base station, a schedule request (SR) for allocating a PUSCH over the PCell; and

in response to transmitting the SR, receive, from the base station, an indication of an allocated PUSCH over the PCell; and

wherein the transmitting the BFRQ for the SCell further comprises:

transmitting, to the base station, the BFRQ for the SCell using a media access control control element (MAC-CE) over the allocated PUSCH over the PCell.

14. The method of claim 13 , wherein the transmitting the SR further comprises:

transmitting the SR to the base station N milliseconds after detection of the beam failure on the SCell, wherein N is a configurable non-negative value or a predefined non-negative value.

15. The method of claim 13 , wherein the transmitting the SR further comprises:

transmitting, to the base station, the BFRQ for the SCell using a buffer status report (BSR) over the allocated PUSCH over the PCell.

16. A non-transitory computer-readable medium having instructions stored thereon that, when executed by one or more processors, causes the one or more processors to perform operations comprising:

detecting a beam failure on a secondary cell (SCell);

generating a beam failure recovery request (BFRQ) for the SCell, wherein the BFRQ comprises a component carrier identifier for the SCell and a first plurality of candidate beam identifiers for a new beam to be used for recovery;

causing to transmit the BFRQ for the SCell over a primary cell (PCell) to a base station;

causing to receive from the base station a response for the BFRQ for the SCell over the SCell or the PCell, wherein the response includes a second plurality of candidate beams; and

selecting one beam from the second plurality of candidate beams and use as the new beam to receive downlink transmission over the SCell.

17. The non-transitory computer-readable device of claim 16 , wherein the causing to transmit the BFRQ for the SCell further comprises:

causing to transmit to the base station the BFRQ for the SCell over a Primary Uplink Control Channel (PUCCH) or a Physical Random Access Channel (PRACH) over the PCell.

18. The non-transitory computer-readable device of claim 16 , wherein the operations further comprise:

determining there is no available Primary Uplink Shared Channel (PUSCH) over the PCell;

causing to transmit to the base station a schedule request (SR) for allocating a PUSCH over the PCell; and

in response to transmitting the SR, causing to receive from the base station an indication of an allocated PUSCH over the PCell; and

wherein the causing to transmit the BFRQ for the SCell further comprises:

causing to transmit to the base station the BFRQ for the SCell using a media access control control element (MAC-CE) over the allocated PUSCH over the PCell.

19. The non-transitory computer-readable device of claim 16 , wherein the causing to transmit the SR further comprises:

causing to transmit the SR to the base station N milliseconds after detection of the beam failure on the SCell, wherein the N milliseconds is a configurable non-negative value or a predefined non-negative value.

20. The non-transitory computer-readable device of claim 16 , wherein the causing to transmit the SR further comprises:

causing to transmit to the base station the BFRQ for the SCell using a buffer status report (BSR) over the allocated PUSCH over the PCell.