Patent Description:
The present disclosure relates generally to communication systems, and more particularly, to a wireless communication system between a user equipment (UE) and a base station.

<NUM> NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra -reliable low latency communications (URLLC).

<CIT> Aldescribes a method and system for reporting a secondary node failure in dual connectivity networks.

The scope of the protection is defined by the claims.

Multiple transmission reception points or Tx/Rx Points (TRPs) may operate to increase capacity and reliability of wireless communication systems. A TRP is typically a set of co-located TX/RX antennas providing coverage in the same sector. The set of TX/RX-points can either be at different locations or co-sited but providing coverage in different sectors, and can also belong to the same or different base stations. For example, a TRP may be a transmission panel of a base station, which generally has a single transmission element. Thus, a base station may comprise a single TRP. Alternatively, a base station may comprise multiple TRPs.

Different modes of multi-TRP (mTRP) operation may be supported in a wireless communication system. In a first mode (e.g. Mode <NUM>), a single PDCCH is used to schedule a single PDSCH transport block (TB) from multiple TRPs in a serving cell. In a second mode (e.g. Mode <NUM>), multiple PDCCHs are used to schedule separate PDSCH TBs from multiple TRPs in a serving cell. In Mode <NUM> multi-TRP operation, separate PDCCH and PSDCHs may be served using different beams. However, such beams may easily fail or be lost, for example, in response to UE movement or due to sudden presence of an obstacle interfering with the beam. As a result, UEs generally perform a beam failure detection (BFD) procedure and a beam failure recovery (BFR) procedure to keep track of possible failure of the PDCCH serving beam of each TRP.

When detecting beam failure and performing beam failure recovery in Mode <NUM> multi-TRP operation, the UE has to track the serving beam(s) of only one PDCCH in a serving cell. However, in Mode <NUM> multi-TRP operation, the UE generally has to track the serving beam(s) of two PDCCH in a serving cell (e.g. one from each TRP) for beam failure detection and recovery. For example, one or more base stations may configure dedicated PRACH resources and candidate beam sets for two TRPs in a serving cell, and the UE has to perform beam failure detection independently for each TRP based on beam failure reference signals associated with each TRP. Moreover, if strong candidate beams with sufficient link quality are unavailable to use for performing beam failure recovery, and the serving cell is a primary or special cell, the UE may be required to perform a contention-based random access procedure for each TRP to recover the PDCCH serving beam for each TRP. This process not only requires additional resources compared to Mode <NUM> multi-TRP operation, but a longer delay in beam failure recovery time may be incurred. Hence, it would be helpful to enhance Mode <NUM> multi-TRP operation.

The present disclosure enhances Mode <NUM> multi-TRP operation by allowing a UE to recover and reconfigure a failed PDCCH beam of a first TRP in a serving cell by using a second TRP which still has a working PDCCH in the same serving cell. For example, if the first TRP undergoes beam failure but the second TRP in the same cell has an operational beam, then rather than performing RACH on the first TRP, the UE may transmit a beam failure indication (e.g. a MAC CE) indicating a new beam for the PDCCH of the first TRP. The base station comprising the second TRP may then reconfigure the PDCCH serving beams of the first TRP based on the beam failure indication. As a result, the present disclosure may increase the reliability of a serving cell.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The apparatus receives data from a first transmission reception point (TRP) and a second TRP in a serving cell based on a physical downlink control channel (PDCCH) of the first TRP and the second TRP. The PDCCH of the first TRP and second TRP are each received over separate beams. Moreover, the apparatus detects beam failure of the PDCCH of the first TRP, and performs beam failure recovery for the first TRP by transmitting a beam failure indication indicating a new beam for the PDCCH of the first TRP.

In another aspect of the disclosure, methods and an apparatus are provided. The apparatus may be a base station comprising one or more TRPs. For instance, the apparatus may be a base station in communication with a first TRP in a serving cell, and the apparatus may comprise a second TRP in the serving cell. The apparatus transmits data to a user equipment (UE) based on a physical downlink control channel (PDCCH) of the second TRP. The PDCCH of the second TRP is transmitted to the UE over a separate beam than a PDCCH of the first TRP. The apparatus receives a beam failure indication from the UE in response to a beam failure of the PDCCH of the first TRP. The apparatus configures a new beam for the PDCCH of the first TRP based on the beam failure indication.

The base stations <NUM> configured for 5GNR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network <NUM> through second backhaul links <NUM>.

Frequency range bands include frequency range <NUM> (FR1), which includes frequency bands below <NUM>, and frequency range <NUM> (FR2), which includes frequency bands above <NUM>. Communications using the mmW / near mmW radio frequency (RF) band (e.g., <NUM> - <NUM>) has extremely high path loss and a short range. Base stations / UEs may operate within one or more frequency range bands.

Some of the UEs <NUM> may be referred to as loT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.).

Referring again to <FIG>, in certain aspects, the UE <NUM> may include a beam recovery component <NUM> which is configured to receive data from a first transmission reception point (TRP) and a second TRP in a serving cell based on a physical downlink control channel (PDCCH) of the first TRP and the second TRP, where the PDCCH of the first TRP and second TRP each received over separate beams. The beam recovery component <NUM> is also configured to detect beam failure of the PDCCH of the first TRP and to perform beam failure recovery for the first TRP by transmitting a beam failure indication indicating a new beam for the PDCCH of the first TRP.

Referring still to <FIG>, in certain aspects, the base station <NUM>/<NUM> may include a beam configuration component <NUM> which is configured to transmit data to a user equipment (UE) based on a physical downlink control channel (PDCCH) of the second TRP, where the PDCCH of the second TRP is transmitted to the UE over a separate beam than a PDCCH of the first TRP. The beam configuration component <NUM> is also configured to receive a beam failure indication from the UE in response to a beam failure of the PDCCH of the first TRP, and to configure a new beam for the PDCCH of the first TRP based on the beam failure indication.

The <NUM>/NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by <FIG>, the <NUM>/NR frame structure is assumed to be TDD, with subframe <NUM> being configured with slot format <NUM> (with mostly DL), where D is DL, U is UL, and F is flexible for use between DL/UL, and subframe <NUM> being configured with slot format <NUM> (with mostly UL).

For slot configuration <NUM>, different numerologies µ <NUM> to <NUM> allow for <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> slots, respectively, per subframe. <FIG> provide an example of slot configuration <NUM> with <NUM> symbols per slot and numerology µ=<NUM> with <NUM> slots per subframe. The slot duration is <NUM>, the subcarrier spacing is <NUM>, and the symbol duration is approximately <NUM>. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see 2B) that are frequency division multiplexed. Each BWP may have a particular numerology.

A PDCCH within one BWP may be referred to as a control resource set (CORESET). Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block (also referred to as SS block (SSB)).

Similarly, a serving cell can have multiple TRPs, with different TRPs for the same serving cell being located on different towers. For example, a serving cell may include a primary cell and any secondary cells, with each cell including one or more TRPs. A primary cell is a cell operating on a primary frequency in which the UE may perform an initial connection establishment procedure or initiates a connection re-establishment procedure with a base station. The primary cell may have a primary TRP for primarily receiving data from the UE and transmitting data to the UE. The primary cell may also have secondary TRPs for providing supplementary transmission and reception capability. Furthermore, a secondary cell may include its own primary and secondary TRPs which provide additional radio resources for a UE configured with carrier aggregation.

On top of secondary cells, a serving cell may include primary secondary cell group cells (PSCell) and special cells (SpCell) for dual connectivity operation. A primary secondary cell group cell is a cell in which a UE may perform random access with a base station when performing a reconfiguration with synchronization procedure. A special cell (SpCell) may be a primary cell (PCell) or a primary secondary cell group cell (PSCell). Thus, a serving cell may comprise a primary cell for UEs not configured with carrier aggregation or dual connectivity, while a serving cell may comprise any secondary cells or special cells for UEs configured with carrier aggregation or dual connectivity.

Different modes of multi-TRP (mTRP) operation may be supported in a wireless communication system. In a first mode (e.g. Mode <NUM>), a single PDCCH is used to schedule a single PDSCH transport block (TB) from multiple TRPs in a serving cell. <FIG> illustrates an example <NUM> of Mode <NUM> multi-TRP operation. In the example of <FIG>, a serving cell <NUM> may include multiple TRPs communicating with a UE <NUM> (e.g. TRP <NUM><NUM> and TRP <NUM><NUM>). TRP <NUM><NUM> may be a primary TRP, while TRP <NUM><NUM> may be a secondary TRP, or vice-versa. Both TRP <NUM><NUM> and TRP <NUM><NUM> may use a single PDCCH <NUM> (e.g. from the primary TRP) to coordinate their transmissions and schedule the same TB on their respective PDSCH <NUM> and <NUM> to UE <NUM>, thereby increasing data throughput. For example, the different TRPs may transmit the same data on PDSCH <NUM> and <NUM> using different spatial layers in overlapping resource blocks (RBs) or symbols (e.g. spatial division multiplexing [SDM], as illustrated in <FIG>), using different RBs in frequency (e.g. frequency division multiplexing [FDM]), or using different OFDM symbols (e.g. time division multiplexing [TDM]). Mode <NUM> multi-TRP operation generally requires ideal backhaul, or at least backhaul with small delay, between TRPs. Thus, TRP <NUM><NUM> and TRP <NUM><NUM> may be two sets of co-located TX/RX antennas (or two sets of one or more antenna arrays) of a single base station with ideal backhaul, or they may be from two different base stations with negligible or low latency in their coordination and transmission. Moreover, each TRP may communicate with the UE <NUM> using one or more beams. For example, TRP <NUM><NUM> may transmit PDCCH <NUM> to UE <NUM> using a PDCCH serving beam <NUM>.

In a second mode (e.g. Mode <NUM>), multiple PDCCHs are used to schedule separate PDSCH TBs from multiple TRPs in a serving cell. <FIG> illustrates an example <NUM> of Mode <NUM> multi-TRP operation. In the example of <FIG>, a serving cell <NUM> may include multiple TRPs in communication with a UE <NUM> (e.g. TRP <NUM><NUM> and TRP <NUM><NUM>). TRP <NUM><NUM> may be a primary TRP, while TRP <NUM><NUM> may be a secondary TRP, or vice-versa. TRPs <NUM>, <NUM> function independently by having their own PDCCH <NUM>, <NUM> for separately scheduling different TBs to UE <NUM> on different PDSCH <NUM>, <NUM>. Mode <NUM> multi-TRP operation may be supported for TRPs with both ideal and non-ideal backhaul (e.g. significant latency or delay in communications prohibiting synchronization of operation between TRPs). Thus, TRP <NUM><NUM> and TRP <NUM><NUM> may be two sets of co-located TX/RX antennas of a single base station, or antenna arrays of two different base stations. Moreover, each TRP may communicate with the UE <NUM> using one or more beams. For example, TRP <NUM><NUM> may transmit PDCCH <NUM> to UE <NUM> using a PDCCH serving beam <NUM>, while TRP <NUM><NUM> may transmit PDCCH <NUM> to UE <NUM> using another PDCCH serving beam <NUM>.

In Mode <NUM> multi-TRP operation, the separate PDCCH and PSDCHs may be served using different beams. For example, to support multiple PDCCH monitoring by the UE, multiple control resource set (CORESETs) may be configured per TRP (e.g. up to <NUM> CORESETs or some other number) up to a maximum number of CORESETS in total (e.g. up to <NUM> CORESETs or some other number), thus allowing each TRP to transmit their PDCCH using multiple beams. Moreover, with millimeter wave (mmW) beamforming, beams may be precisely configured to allow TRPs to send information to and receive information from the UE at high frequencies. However, such beams may easily fail or be lost, for example, in response to UE movement or due to sudden presence of an obstacle interfering with the beam. As a result, UEs generally perform a beam failure detection (BFD) procedure to keep track of possible failure of the PDCCH serving beam of each TRP.

<FIG> illustrates an example <NUM> of a BFD procedure performed by a UE <NUM> in communication with a TRP <NUM> of a base station. TRP <NUM> may correspond, for example, to TRP <NUM> of <FIG>. In operation, TRP <NUM> provides to UE <NUM> one or more BFD reference-signal (RS) resources <NUM> over one or more PDCCH serving beams. In some aspects, only one PDCCH serving beam is implemented; in other aspects, TRP <NUM> may be configured with a second, wider PDCCH beam to allow for communication between the TRP <NUM> and UE <NUM> if the first PDCCH serving beam fails. For example, TRP <NUM> may configure up to two BFD RS resources respectively associated with each of the one or more PDCCH serving beams, and provide those RS resources to UE <NUM>. In one aspect, the BFD RS resources <NUM> may comprise periodic CSI-RS resource configuration indexes configured by TRP <NUM> and transmitted to the UE <NUM> (e.g. in a higher layer parameter failureDetectionResources or some other name).

Using the BFD RS resources, at block <NUM>, the UE can periodically measure a link quality of the PDCCH serving beam(s) to detect whether beam failure occurs. Alternatively, if TRP <NUM> does not provide BFD RS resources <NUM> for the UE to measure for link quality, the UE may instead measure CSI-RS resources periodically communicated over the one or more PDCCH serving beams which have a quasi-colocation (QCI) relationship with a beam the UE may use to monitor PDCCH. Based on the BFD RS resources <NUM> (or periodic CSI-RS resources), the physical (PHY) layer of the UE measures the link quality of the beams by identifying a reference signal received power (RSRP) of the RS resources and determining whether they are below a RSRP threshold preconfigured by TRP <NUM>.

If the link quality is determined to be below the threshold, the PHY layer of the UE sends a beam failure indication (or BFD indication) to an upper layer (e.g. the medium access control (MAC) layer) of the UE <NUM>. The MAC layer maintains a dynamic BFD counter, which the UE increments by one (at block <NUM>) whenever a BFD indication is received from the PHY layer. The MAC layer also maintains a timer, which resets the BFD counter to zero whenever a BFD indication is not received after a pre-configured time. When the counter reaches a preconfigured maximum value, the UE detects beam failure <NUM> of the PDCCH serving beam(s) associated with the BFD RS resources <NUM>. The UE <NUM> may then perform beam failure recovery at block <NUM> based on a set of candidate beams from which the UE can select a new beam, the details of which are described immediately below.

<FIG> illustrates an example <NUM> of a beam failure recovery procedure (occurring after the beam failure detection procedure of <FIG>) which a UE <NUM> performs to recover its PDCCH serving beams. Initially prior to beam failure, a base station comprising TRP <NUM> configures a set of candidate beams at block <NUM> which the UE <NUM> may use to recover a PDCCH serving beam. The TRP <NUM> may correspond to TRP <NUM> of <FIG>. The set of candidate beams may be a subset of a total set of beams transmitted by TRP <NUM>. For example, the set of candidate beams may include a number of adjacent beams directed towards the location of the UE (e.g. where beam failure had occurred), with each beam having an identical beamwidth to the failed beam and/or a wider beamwidth than the failed beam. In one aspect, the set of candidate beams may comprise periodic CSI-RS resource configuration indexes and/or SS/PBCH block indexes configured for the TRP <NUM> and which are transmitted to the UE <NUM> (e.g. in a higher layer parameter candidateBeamRSList or some other name). After the candidate beams are configured, the TRP <NUM> provides the set of candidate beams <NUM> to the UE <NUM>.

At block <NUM>, the UE <NUM> may detect failure of a PDCCH serving beam as described above with respect to <FIG>. For example, the UE <NUM> may detect that the PDCCH serving beam for TRP <NUM> has failed. Accordingly, the UE selects at block <NUM> a new beam from the set of candidate beams <NUM> to recover the PDCCH serving beam. The beam selection is based on link quality. For example, the UE <NUM> may measure the RSRP for each beam in the set of candidate beams (for example, based on CSI-RS associated with each beam), and select a new beam having a RSRP over a pre-configured threshold. If the serving cell in which beam failure is detected is a secondary cell (e.g. TRP <NUM> is in a secondary cell), the UE may indicate its preferred new beam to a base station in a primary cell at block <NUM>. For example, the UE <NUM> may send a medium access control (MAC) control element (CE) to a base station in the primary cell to reconfigure the new PDCCH beam for TRP <NUM>. The MAC CE may include the index of the secondary cell in which beam failure was detected, and the index of the UE's selected beam from the set of candidate beams.

The TRP <NUM> may also configure, at block <NUM>, physical random access channel (PRACH) resources for beam failure recovery and provide the PRACH configuration <NUM> to the UE. For example, the PRACH configuration may include a unique preamble configured for the UE <NUM> to use when performing a contention-free random access (CFRA) procedure to reacquire a connection with TRP <NUM> in the event of beam failure. Alternatively, the TRP <NUM> may not configure any PRACH resources for beam failure recovery, and the UE may perform a contention-based random access (CBRA) procedure to reacquire the connection with TRP <NUM> in the event of beam failure. If the serving cell in which beam failure occurs is a primary cell or a special cell, the UE may perform a CFRA or CBRA RACH procedure <NUM> to indicate its preferred new beam for the PDCCH to TRP <NUM>. In either CFRA or CBRA, each PRACH occasion may be associated with a respective beam in the set of candidate beams, and the PRACH configuration <NUM> may indicate the transmission occasions associated with each beam to the UE <NUM>.

Thus, in one aspect, if the UE <NUM> is configured with dedicated PRACH resources and identifies a new beam from the set of candidate beams with sufficient link quality (e.g. having a RSRP over a pre-configured threshold), the UE may perform CFRA with TRP <NUM> by initially transmitting a preamble in the PRACH occasion corresponding to the identified beam. For example, if the set of candidate beams is comprised of three beams, and beam two is of sufficient link quality, the UE may select beam two and transmit the preamble in the second transmission occasion (e.g. associated with beam two) within a PRACH configuration period. Upon completion of the RACH procedure, the TRP <NUM> may subsequently reconfigure its PDCCH serving beam to correspond to the UE's selected beam two.

Alternatively, if the UE <NUM> is unable to select a new beam from the set of candidate beams (none of the candidate beams have sufficient link quality or RSRP exceeding the preconfigured threshold), or the base station comprising TRP <NUM> does not configure dedicated PRACH resources to the UE for beam failure recovery, the UE may perform CBRA with TRP <NUM> over common PRACH resources. In this aspect, the UE may select a beam among a total set of beams transmitted by TRP <NUM>, e.g., based on synchronization signal blocks (SSBs) transmitted in the serving cell, and the UE may transmit a preamble in the PRACH transmission occasion corresponding to the identified beam. For example, the UE may select beam three based on a SSB received from TRP <NUM> and transmit a preamble in the third transmission occasion (e.g. associated with beam three) within a PRACH configuration period. Upon completion of the RACH procedure, the TRP <NUM> may subsequently reconfigure its PDCCH serving beam to correspond to the UE's selected beam three.

Thus, when detecting beam failure and performing beam failure recovery in Mode <NUM> multi-TRP operation, the UE has to track the serving beam(s) of only one PDCCH in a serving cell. However, in Mode <NUM> multi-TRP operation, the UE generally has to track the serving beam(s) of two PDCCH in a serving cell (e.g. one from each TRP) for beam failure detection and recovery. For example, one or more base stations may configure dedicated BFR PRACH resources and candidate beam sets for both TRPs, and the UE has to perform beam failure detection independently for each TRP based on beam failure reference signals associated with each TRP. Moreover, if strong candidate beams with sufficient link quality are unavailable and the serving cell is a primary or special cell, the UE may be required to perform CBRA for each TRP to recover the PDCCH serving beam for each TRP. This process not only requires additional resources compared to Mode <NUM> multi-TRP operation, but a longer delay in beam failure recovery time may be incurred. Hence, it would be helpful to enhance Mode <NUM> multi-TRP operation.

Aspects of the present disclosure enhance Mode <NUM> multi-TRP operation by allowing a UE to recover and reconfigure a failed PDCCH beam of a first TRP in a serving cell by using a second TRP which still has a working PDCCH in the same serving cell. For example, if the first TRP undergoes beam failure but the second TRP in the same cell has an operational beam, then rather than performing RACH on the first TRP, the UE may transmit a beam failure indication (e.g. a MAC CE) indicating a new beam for the PDCCH of the first TRP. The base station comprising the second TRP may then reconfigure the PDCCH serving beams of the first TRP based on the beam failure indication.

However, if the second TRP also undergoes beam failure while beam failure recovery is being performed for the first TRP, and the serving cell is a primary cell or a special cell, the UE only performs RACH on the primary TRP rather than both the primary TRP and secondary TRP. For instance, the UE may perform CFRA with the primary TRP to indicate a new beam if one or more candidate beams have sufficient link quality. Alternatively, the UE may perform CBRA with the primary TRP to indicate a new beam if no candidate beams have sufficient link quality. After the UE performs beam failure recovery using RACH on the primary TRP, the UE may perform beam failure recovery for the second TRP by transmitting a beam failure indication (e.g. a MAC CE). The base station comprising the primary TRP may then reconfigure the PDCCH serving beams of the secondary TRP based on the beam failure indication. Alternatively, if the serving cell is a secondary cell, the UE may simply transmit a beam failure indication (e.g. a MAC CE) in another secondary cell to reconfigure the failed PDCCH serving beam. The beam failure indication may include the index of the SCell where beam failure has occurred and the index of a selected candidate beam by the UE. As a result, the reliability of a serving cell may be increased.

<FIG> illustrates an example <NUM> of a beam failure detection and recovery procedure performed by a UE <NUM> in communication with a TRP <NUM> and TRP <NUM> in Mode <NUM> multi-TRP operation. TRP <NUM> may correspond, for example, to TRP <NUM> of <FIG>, and TRP <NUM> may correspond, for example, to TRP <NUM> of <FIG> within the same serving cell. One or more base stations comprising TRP <NUM> and/or TRP <NUM> may configure the TRP <NUM> to transmit one set of BFD RS resources <NUM> and TRP <NUM> to transmit another set of BFD RS resources <NUM>. TRP <NUM> and <NUM> may provide UE <NUM> the RS resources <NUM>, <NUM> over different PDCCH serving beams (e.g. PDCCH serving beams <NUM> and <NUM>). In one aspect, the BFD RS resources <NUM>, <NUM> may comprise periodic CSI-RS resource configuration indexes configured by TRP <NUM>, <NUM> and transmitted to the UE <NUM> (e.g. in higher layer parameters failureDetectionResources or some other name).

The one or more base stations comprising TRP <NUM> and/or TRP <NUM> may also configure each TRP with a set of candidate beams <NUM>, <NUM> which the UE <NUM> may respectively use to recover the PDCCH serving beam of each TRP <NUM>, <NUM>. TRP <NUM> and TRP <NUM> may each provide a beam failure recovery configuration <NUM>, <NUM> to the UE <NUM> including their respective sets of candidate beams. Each set of candidate beams may be a subset of the total set of beams transmitted by the respective TRP <NUM>, <NUM>. In one aspect, each set of candidate beams may comprise periodic CSI-RS resource configuration indexes and/or SS/PBCH block indexes (e.g. in a higher layer parameter candidateBeamRSList or some other name).

TRPs <NUM>, <NUM> may also provide a BFD PRACH configuration to the UE <NUM>. For example, assuming TRP <NUM> is the primary TRP, the base station comprising TRP <NUM> may configure PRACH resources <NUM> for the UE <NUM> to use for beam failure recovery of the PDCCH for TRP <NUM>. For example, the PRACH resources may include a unique preamble configured for the UE <NUM> to use when performing a CFRA procedure to reacquire a connection with TRP <NUM>. Alternatively, the TRP <NUM> may not configure any PRACH resources for beam failure recovery, and the UE may instead perform a CBRA procedure to reacquire the connection with TRP <NUM> in the event of beam failure of the primary TRP. In either type of procedure, the PRACH configuration <NUM> transmitted to the UE may include RACH transmission occasions associated with each beam in the set of candidate beams. Additionally, the primary TRP may provide the PRACH configuration <NUM> to the UE in the beam failure recovery configuration <NUM> (along with the set of candidate beams), rather than in a separate message as illustrated for example in <FIG>.

At block <NUM>, the UE <NUM> detects beam failure for each TRP <NUM>, <NUM> independently. For example, using the BFD RS resources <NUM>, <NUM> from each TRP <NUM>, <NUM>, the UE may periodically measure a link quality of the PDCCH serving beam(s) from each TRP to detect whether beam failure occurs at each TRP. Based on the BFD RS resources, the UE may determine whether an RSRP associated with each beam is below a RSRP threshold preconfigured by the one or more base stations comprising TRP <NUM>, <NUM>. If the link quality of a beam is below the threshold, the UE increments a dynamic BFD counter associated with the TRP transmitting the beam. When the counter reaches a preconfigured maximum value for a particular TRP, the UE detects beam failure of the PDCCH serving beam(s) from that TRP.

In this example, a beam failure <NUM> may be detected for TRP <NUM> while the PDCCH serving beam of TRP <NUM> (in the same serving cell) is operational. Accordingly, in response to the beam failure detection, the UE <NUM> may perform beam failure recovery <NUM> to recover the PDCCH serving beam for the TRP <NUM> by transmitting a beam failure indication <NUM>. The beam failure indication <NUM> may be a MAC CE indicating a new beam which the UE <NUM> has selected based on link quality from the set of candidate beams received from TRP <NUM>. For example, when performing beam failure recovery <NUM> for the PDCCH of TRP <NUM>, the UE <NUM> may select at block <NUM> a new beam from TRP <NUM>'s set of candidate beams and transmit the beam failure indication <NUM>. For instance, the UE <NUM> may measure the RSRP of each beam in the set of candidate beams, identify a new beam having a RSRP over a pre-configured threshold, and subsequently transmit the index of that selected beam in the MAC CE.

The base station comprising TRP <NUM> may receive the beam failure indication <NUM> and then reconfigure the PDCCH as well as the PDSCH beam for TRP <NUM> using the PDCCH and PSDCH of TRP <NUM>. For example, TRP <NUM> may send to the UE <NUM> a transmission configuration indicator (TCI) state indication <NUM> for a UE-specific PDCCH MAC CE and a TCI state activation indicator <NUM> (activation/deactivation) for a UE-specific PDSCH MAC CE. Based on the TCI state indicator <NUM> and/or TCI state activation indicator <NUM>, the UE may communicate with TRP <NUM> using the new beam.

In certain aspects, another beam failure may be detected for TRP <NUM> at block <NUM> while the UE is still performing beam failure recovery <NUM> for the PDCCH of TRP <NUM>. In such case, the UE <NUM> may perform another beam failure recovery <NUM> to recover the PDCCH of TRP <NUM> at the same time as it performs beam failure recovery <NUM> to recover the PDCCH of TRP <NUM>. In one example, the serving cell in which beam failures are detected at blocks <NUM> and <NUM> may be a secondary cell. In such case, when performing beam failure recovery <NUM> for the PDCCH of TRP <NUM>, the UE <NUM> may select a new beam at block <NUM> from the set of candidate beams for TRP <NUM> and transmit a beam failure indication <NUM> (e.g. a MAC CE) in another secondary cell (e.g. including a third TRP <NUM> whose PDCCH beam is currently in operation). The MAC CE may include the index of the secondary cell in which beam failure was detected, and the index of the UE's selected beam from the set of candidate beams. The base station comprising TRP <NUM> may receive the beam failure indication <NUM> and then reconfigure the PDCCH as well as the PDSCH beam for TRP <NUM> (or TRP <NUM>) using the PDCCH and PSDCH of TRP <NUM> as described above.

In another example, the serving cell in which beam failures are detected at blocks <NUM> and <NUM> may be a primary cell or a special cell. In such case, the UE <NUM> may perform beam recovery for the PDCCH of the primary TRP as described above with respect to <FIG>. For example, if TRP <NUM> is the primary TRP, the UE may perform a CFRA or CBRA RACH procedure <NUM> with TRP <NUM> based on the beam failure recovery configuration <NUM> (or PRACH resources). In either procedure, the UE may transmit a preamble in the PRACH transmission occasion corresponding to the identified beam to indicate its preferred new beam for the PDCCH of the primary TRP. After successfully completing beam failure recovery on the primary TRP (e.g. TRP <NUM>), the UE may then transmit a beam failure indication <NUM> (e.g. a MAC CE) for the primary TRP to reconfigure the PDCCH beam for the secondary TRP (e.g. TRP <NUM>) using the PDCCH and PDSCH of TRP <NUM> as described above.

<FIG> is a flowchart <NUM> of a method of wireless communication. The method may be performed by a UE (e.g., the UE <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>; the apparatus <NUM>/<NUM>'; the processing system <NUM>, which may include the memory <NUM> and which may be the entire UE <NUM> or a component of the UE <NUM>, such as the TX processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>). Optional aspects are illustrated in dashed lines.

At <NUM>, the UE receives data from a first transmission reception point (TRP) and a second TRP in a serving cell based on a physical downlink control channel (PDCCH) of the first TRP and the second TRP, the PDCCH of the first TRP and second TRP each received over separate beams. For example, <NUM> may be performed by PDCCH component <NUM> in <FIG>. For instance, referring to <FIG>, a serving cell <NUM> may include multiple TRPs in communication with a UE <NUM> (e.g. TRP <NUM><NUM> and TRP <NUM><NUM>). Each TRP may communicate with the UE <NUM> using one or more beams. For example, TRP <NUM><NUM> may transmit PDCCH <NUM> to UE <NUM> using a PDCCH serving beam <NUM>, while TRP <NUM><NUM> may transmit PDCCH <NUM> to UE <NUM> using another PDCCH serving beam <NUM>.

At <NUM>, the UE detects beam failure of the PDCCH of the first TRP. For example, <NUM> may be performed by detection component <NUM> in <FIG>. The beam failure may be detected based on one or more reference signals received from the first TRP and the second TRP. The beam failure is detected for the first TRP independently from the second TRP. For example, referring to <FIG>, one or more base stations comprising TRP <NUM> and/or TRP <NUM> may configure the TRP <NUM> to transmit one set of BFD RS resources <NUM> and TRP <NUM> to transmit another set of BFD RS resources <NUM>. At block <NUM>, the UE <NUM> detects beam failure for each TRP <NUM>, <NUM> independently. For example, using the BFD RS resources <NUM>, <NUM> from each TRP <NUM>, <NUM>, the UE may periodically measure a link quality of the PDCCH serving beam(s) from each TRP to detect whether beam failure occurs at each TRP. Based on the BFD RS resources, the UE may determine whether an RSRP associated with each beam is below a RSRP threshold preconfigured by the one or more base stations comprising TRP <NUM>, <NUM>. If the link quality of a beam is below the threshold, the UE increments a dynamic BFD counter associated with the TRP transmitting the beam. When the counter reaches a preconfigured maximum value for a particular TRP, the UE detects beam failure of the PDCCH serving beam(s) from that TRP.

At <NUM>, the UE performs beam failure recovery for the first TRP by transmitting a beam failure indication indicating a new beam for the PDCCH of the first TRP. For example, <NUM> may be performed by recovery component <NUM> in <FIG>. The beam failure recovery may be performed based on a beam failure recovery configuration comprising a set of candidate beams for the first TRP and the second TRP. In one aspect, beam failure recovery may be performed for the PDCCH of the first TRP while the beam for the PDCCH of the second TRP is operational. In this aspect, the beam failure indication comprises a medium access control (MAC) control element (CE) indicating a new beam for the PDCCH of the first TRP. For example, referring to <FIG>, the one or more base stations comprising TRP <NUM> and/or TRP <NUM> may configure each TRP with a set of candidate beams <NUM>, <NUM> which the UE <NUM> may respectively use to recover the PDCCH serving beam of each TRP <NUM>, <NUM>. TRP <NUM> and TRP <NUM> may each provide a beam failure recovery configuration <NUM>, <NUM> to the UE <NUM> including their respective sets of candidate beams. In this example, a beam failure <NUM> may be detected for TRP <NUM> while the PDCCH serving beam of TRP <NUM> (in the same serving cell) is operational. Accordingly, in response to the beam failure detection, the UE <NUM> may perform beam failure recovery <NUM> to recover the PDCCH serving beam for the TRP <NUM> by transmitting a beam failure indication <NUM>. The beam failure indication <NUM> may be a MAC CE indicating a new beam which the UE <NUM> has selected based on link quality from the set of candidate beams received from TRP <NUM>.

Beam failure recovery may be performed for the PDCCH of the first TRP based on a transmission configuration indicator (TCI) state indication for a UE-specific PDCCH MAC CE received from the second TRP. Beam failure recovery may be further performed for a physical downlink shared channel (PDSCH) of the first TRP based on a transmission configuration indicator (TCI) state activation indication for a UE-specific PDSCH MAC CE received from the second TRP. For example, referring to <FIG>, the base station comprising TRP <NUM> may receive the beam failure indication <NUM> and then reconfigure the PDCCH as well as the PDSCH beam for TRP <NUM> using the PDCCH and PSDCH of TRP <NUM>. For example, TRP <NUM> may send to the UE <NUM> a transmission configuration indicator (TCI) state indication <NUM> for a UE-specific PDCCH MAC CE and a TCI state activation indicator <NUM> (activation/deactivation) for a UE-specific PDSCH MAC CE. Based on the TCI state indicator <NUM> and/or TCI state activation indicator <NUM>, the UE may communicate with TRP <NUM> using the new beam.

In another aspect, at <NUM>, the UE may detect beam failure of the PDCCH of the second TRP. For example, <NUM> may be performed by detection component <NUM> in <FIG>. For example, referring to <FIG>, another beam failure may be detected as described above, but for TRP <NUM> at block <NUM> while the UE is still performing beam failure recovery <NUM> for the PDCCH of TRP <NUM>.

Accordingly, at <NUM>, the UE may perform beam failure recovery for the PDCCH of the second TRP at the same time as the first TRP. For example, <NUM> may be performed by recovery component <NUM> in <FIG>. In one aspect, the serving cell comprises a secondary cell, and the beam failure recovery is performed for the PDCCH of the second TRP by transmitting a beam failure indication in a different secondary cell. The beam failure indication comprises a medium access control (MAC) control element (CE) indicating a new beam for the PDCCH of the second TRP. For example, referring to <FIG>, the UE <NUM> may perform another beam failure recovery <NUM> to recover the PDCCH of TRP <NUM> at the same time as it performs beam failure recovery <NUM> to recover the PDCCH of TRP <NUM>. In one example, the serving cell in which beam failures are detected at blocks <NUM> and <NUM> may be a secondary cell. In such case, when performing beam failure recovery <NUM> for the PDCCH of TRP <NUM>, the UE <NUM> may select a new beam at block <NUM> from the set of candidate beams for TRP <NUM> and transmit a beam failure indication <NUM> (e.g. a MAC CE) in another secondary cell (e.g. including a third TRP <NUM> whose PDCCH beam is currently in operation). The MAC CE may include the index of the secondary cell in which beam failure was detected, and the index of the UE's selected beam from the set of candidate beams. The base station comprising TRP <NUM> may receive the beam failure indication <NUM> and then reconfigure the PDCCH as well as the PDSCH beam for TRP <NUM> (or TRP <NUM>) using the PDCCH and PSDCH of TRP <NUM> as described above.

In another aspect, the serving cell comprises a special cell, and the special cell comprises one of a primary cell or a primary secondary cell group cell. In this aspect, at <NUM>, the UE may perform a random access channel (RACH) procedure indicating a new beam for a PDCCH of the primary TRP. For example, <NUM> may be performed by RACH component <NUM> in <FIG>. A physical RACH (PRACH) preamble is transmitted in a PRACH occasion associated with the new beam during the RACH procedure. The first TRP may comprise a primary TRP, and the second TRP may comprise a secondary TRP. For example, referring to <FIG>, the serving cell in which beam failures are detected at blocks <NUM> and <NUM> may be a primary cell or a special cell. In such case, the UE <NUM> may perform beam recovery for the PDCCH of the primary TRP as described above with respect to <FIG>. For example, if TRP <NUM> is the primary TRP, the UE may perform a CFRA or CBRA RACH procedure <NUM> with TRP <NUM> based on the beam failure recovery configuration <NUM> (or PRACH resources). In either procedure, the UE may transmit a preamble in the PRACH transmission occasion corresponding to the identified beam to indicate its preferred new beam for the PDCCH of the primary TRP.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different means/components in an example apparatus <NUM>. The apparatus may be a UE (e.g. the UE <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) in communication with one or more base stations <NUM>, <NUM> (e.g. base station <NUM>/<NUM>, <NUM>) comprising one or more TRPs (e.g. TRP <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>). The apparatus includes a reception component <NUM> that is configured to receive downlink communications from one or more TRPs. The apparatus includes a PDCCH component <NUM> that is configured to receive data from a first transmission reception point (TRP) and a second TRP in a serving cell based on a physical downlink control channel (PDCCH) of the first TRP and the second TRP, the PDCCH of the first TRP and second TRP each received over separate beams, e.g., as described in connection with <NUM> in <FIG>. The apparatus includes a detection component <NUM> that is configured to detecting beam failure of the PDCCH of the first TRP, e.g., as described in connection with <NUM> in <FIG>. The detection component <NUM> is also configured to detect beam failure of the PDCCH of the second TRP, e.g., as described in connection with <NUM> in <FIG>. The apparatus includes a recovery component <NUM> that is configured to perform beam failure recovery for the first TRP by transmitting a beam failure indication indicating a new beam for the PDCCH of the first TRP, e.g., as described in connection with <NUM> in <FIG>. The recovery component <NUM> is also configured to perform beam failure recovery for the PDCCH of the second TRP at the same time as the first TRP, e.g., as described in connection with <NUM> in <FIG>. The apparatus includes a transmission component <NUM> that is configured to transmit uplink communications to the one or more base stations. The apparatus includes a RACH component <NUM> that is configured to perform a random access channel (RACH) procedure indicating a new beam for a PDCCH of the primary TRP, e.g., as described in connection with <NUM> in <FIG>.

<FIG> is a diagram <NUM> illustrating an example of a hardware implementation for an apparatus <NUM>' employing a processing system <NUM>. The processing system <NUM> may be implemented with a bus architecture, represented generally by the bus <NUM>. The bus <NUM> may include any number of interconnecting buses and bridges depending on the specific application of the processing system <NUM> and the overall design constraints. The bus <NUM> links together various circuits including one or more processors and/or hardware components, represented by the processor <NUM>, the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and the computer-readable medium / memory <NUM>. The bus <NUM> may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processing system <NUM> may be coupled to a transceiver <NUM>. The transceiver <NUM> is coupled to one or more antennas <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatus over a transmission medium. The transceiver <NUM> receives a signal from the one or more antennas <NUM>, extracts information from the received signal, and provides the extracted information to the processing system <NUM>, specifically the reception component <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically the transmission component <NUM>, and based on the received information, generates a signal to be applied to the one or more antennas <NUM>. The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium / memory <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium / memory <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described supra for any particular apparatus. The computer-readable medium / memory <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system <NUM> further includes at least one of the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The components may be software components running in the processor <NUM>, resident/stored in the computer readable medium / memory <NUM>, one or more hardware components coupled to the processor <NUM>, or some combination thereof. The processing system <NUM> may be a component of the UE <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM>. Alternatively, the processing system <NUM> may be the entire UE (e.g., see <NUM> of <FIG>).

In one configuration, the apparatus <NUM>/<NUM>' for wireless communication includes means for receiving data from a first transmission reception point (TRP) and a second TRP in a serving cell based on a physical downlink control channel (PDCCH) of the first TRP and the second TRP, the PDCCH of the first TRP and second TRP each received over separate beams; means for detecting beam failure of the PDCCH of the first TRP; and means for performing beam failure recovery for the first TRP by transmitting a beam failure indication indicating a new beam for the PDCCH of the first TRP. In one configuration, the means for detecting may be further configured to detect beam failure of the PDCCH of the second TRP. In one configuration, the means for performing may be further configured to perform beam failure recovery for the PDCCH of the second TRP at the same time as the first TRP. In one configuration, the apparatus may also include means for performing a random access channel (RACH) procedure indicating a new beam for a PDCCH of the primary TRP.

<FIG> is a flowchart <NUM> of a method of wireless communication. The method may be performed by a base station (e.g., the base station <NUM>/<NUM>, <NUM>; the apparatus <NUM>/<NUM>'; the processing system <NUM>, which may include the memory <NUM> and which may be the entire base station <NUM> or a component of the base station <NUM>, such as the TX processor <NUM>, the RX processor <NUM>, and/or the controller/processor <NUM>). The base station may communicate with a first TRP in a serving cell (e.g., the TRPs <NUM>, <NUM>, <NUM>), and the base station may comprise a second TRP in the serving cell (e.g. the TRPs <NUM>, <NUM>, <NUM>). The base station may alternatively comprise the first TRP and second TRP. Optional aspects are illustrated in dashed lines.

At <NUM>, the base station transmits data to a user equipment (UE) based on a physical downlink control channel (PDCCH) of the second TRP, wherein the PDCCH of the second TRP is transmitted to the UE over a separate beam than a PDCCH of the first TRP. For example, <NUM> may be performed by beam component <NUM> in <FIG>. For instance, referring to <FIG>, a serving cell <NUM> may include multiple TRPs in communication with a UE <NUM> (e.g. TRP <NUM><NUM> and TRP <NUM><NUM>). Each TRP may communicate with the UE <NUM> using one or more beams. For example, TRP <NUM><NUM> may transmit PDCCH <NUM> to UE <NUM> using a PDCCH serving beam <NUM>, while TRP <NUM><NUM> may transmit PDCCH <NUM> to UE <NUM> using another PDCCH serving beam <NUM>.

At <NUM>, the base station receives a beam failure indication from the UE in response to a beam failure of the PDCCH of the first TRP. For example, <NUM> may be performed by beam failure component <NUM> in <FIG>. The beam failure indication may be received based on one or more reference signals of the first TRP and the second TRP. The beam failure indication may comprise a medium access control (MAC) control element (CE) indicating a new beam for the PDCCH of the first TRP. In one aspect, the new beam is configured for the PDCCH of the first TRP while the beam for the PDCCH of the second TRP is operational. For example, referring to <FIG>, one or more base stations comprising TRP <NUM> and/or TRP <NUM> may configure the TRP <NUM> to transmit one set of BFD RS resources <NUM> and TRP <NUM> to transmit another set of BFD RS resources <NUM>. At block <NUM>, the UE <NUM> detects beam failure for each TRP <NUM>, <NUM> independently. For example, using the BFD RS resources <NUM>, <NUM> from each TRP <NUM>, <NUM>, the UE may periodically measure a link quality of the PDCCH serving beam(s) from each TRP to detect whether beam failure occurs at each TRP. In this example, a beam failure <NUM> may be detected for TRP <NUM> while the PDCCH serving beam of TRP <NUM> (in the same serving cell) is operational. Accordingly, in response to the beam failure detection, the UE <NUM> may perform beam failure recovery <NUM> to recover the PDCCH serving beam for the TRP <NUM> by transmitting a beam failure indication <NUM>. The beam failure indication <NUM> may be a MAC CE indicating a new beam which the UE <NUM> has selected based on link quality from the set of candidate beams received from TRP <NUM>. The base station comprising TRP <NUM> may receive the beam failure indication <NUM>.

At <NUM>, the base station configures a new beam for the PDCCH of the first TRP based on the beam failure indication. For example, <NUM> may be performed by configuration component <NUM> in <FIG>. The new beam may be configured based on a beam failure recovery configuration comprising a set of candidate beams for the first TRP and the second TRP. The new beam may be configured for the PDCCH of the first TRP based on a transmission configuration indicator (TCI) state indication for a UE-specific PDCCH MAC CE transmitted from the second TRP. Another beam may also be configured for a physical downlink shared channel (PDSCH) of the first TRP based on a transmission configuration indicator (TCI) state activation indication for a UE-specific PDSCH MAC CE transmitted from the second TRP. For example, referring to <FIG>, the one or more base stations comprising TRP <NUM> and/or TRP <NUM> may configure each TRP with a set of candidate beams <NUM>, <NUM> which the UE <NUM> may respectively use to recover the PDCCH serving beam of each TRP <NUM>, <NUM>. TRP <NUM> and TRP <NUM> may each provide a beam failure recovery configuration <NUM>, <NUM> to the UE <NUM> including their respective sets of candidate beams. The base station comprising TRP <NUM> may receive the beam failure indication <NUM> and then reconfigure the PDCCH as well as the PDSCH beam for TRP <NUM> using the PDCCH and PSDCH of TRP <NUM>. For example, TRP <NUM> may send to the UE <NUM> a transmission configuration indicator (TCI) state indication <NUM> for a UE-specific PDCCH MAC CE and a TCI state activation indicator <NUM> (activation/deactivation) for a UE-specific PDSCH MAC CE. Based on the TCI state indicator <NUM> and/or TCI state activation indicator <NUM>, the UE may communicate with TRP <NUM> using the new beam.

In another aspect, at <NUM>, the base station receives a configuration of a new beam for the PDCCH of the second TRP in response to a beam failure of the PDCCH of the second TRP, the beam failure occurring before the new beam for the PDCCH of the first TRP is configured. For example, <NUM> may be performed by new beam component <NUM> in <FIG>. In one aspect, the serving cell comprises a secondary cell, and the configuration of the new beam is received from a third TRP in a different secondary cell. For example, referring to <FIG>, another beam failure may be detected as described above, but for TRP <NUM> at block <NUM> while the UE is still performing beam failure recovery <NUM> for the PDCCH of TRP <NUM>. In one example, the serving cell in which beam failures are detected at blocks <NUM> and <NUM> may be a secondary cell. In such case, when performing beam failure recovery <NUM> for the PDCCH of TRP <NUM>, the UE <NUM> may select a new beam at block <NUM> from the set of candidate beams for TRP <NUM> and transmit a beam failure indication <NUM> (e.g. a MAC CE) in another secondary cell (e.g. including a third TRP <NUM> whose PDCCH beam is currently in operation). The MAC CE may include the index of the secondary cell in which beam failure was detected, and the index of the UE's selected beam from the set of candidate beams. The base station comprising TRP <NUM> may receive the beam failure indication <NUM> and then reconfigure the PDCCH as well as the PDSCH beam for TRP <NUM> (or TRP <NUM>) using the PDCCH and PSDCH of TRP <NUM> as described above.

In another aspect, the serving cell comprises a special cell, and the special cell comprises one of a primary cell or a primary secondary cell group cell. In such case, the first TRP comprises a primary TRP, the second TRP comprises a secondary TRP, and the configuration of the new beam is received from the primary TRP. Alternatively, the second TRP may comprise the primary TRP, and the configuration of the new beam is based on a physical random access channel (PRACH) preamble received in a PRACH occasion associated with the new beam. For example, referring to <FIG>, the serving cell in which beam failures are detected at blocks <NUM> and <NUM> may be a primary cell or a special cell. In such case, the UE <NUM> may perform beam recovery for the PDCCH of the primary TRP as described above with respect to <FIG>. For example, if TRP <NUM> is the primary TRP, the UE may perform a CFRA or CBRA RACH procedure <NUM> with TRP <NUM> based on the beam failure recovery configuration <NUM> (or PRACH resources). In either procedure, the UE may transmit a preamble in the PRACH transmission occasion corresponding to the identified beam to indicate its preferred new beam for the PDCCH of the primary TRP. After successfully completing beam failure recovery on the primary TRP (e.g. TRP <NUM>), the UE may then transmit a beam failure indication <NUM> (e.g. a MAC CE) for the primary TRP to reconfigure the PDCCH beam for the secondary TRP (e.g. TRP <NUM>) using the PDCCH and PDSCH of TRP <NUM> as described above.

<FIG> is a conceptual data flow diagram <NUM> illustrating the data flow between different means/components in an example apparatus <NUM>. The apparatus may be a base station (e.g. base station <NUM>/<NUM>, <NUM>) which may communicate with a first TRP in a serving cell (e.g., the TRPs <NUM>, <NUM>, <NUM>), and may comprise a second TRP in the serving cell (e.g. the TRPs <NUM>, <NUM>, <NUM>). The base station may also comprise the first and second TRPs. The apparatus includes a reception component <NUM> that is configured to receive uplink communications from a UE <NUM> (e.g. UE <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) as well as communications from other base stations/TRPs <NUM>. The apparatus includes a transmission component <NUM> that is configured to transmit downlink communications to the UE as well as communications to other base stations/TRPs. The apparatus includes a beam component <NUM> that is configured to transmit data to a user equipment (UE) based on a physical downlink control channel (PDCCH) of the second TRP, where the PDCCH of the second TRP is transmitted to the UE over a separate beam than a PDCCH of the first TRP, e.g., as described in connection with <NUM> of <FIG>. The apparatus includes a beam failure component <NUM> which is configured to receive a beam failure indication from the UE in response to a beam failure of the PDCCH of the first TRP, e.g., as described in connection with <NUM> of <FIG>. The apparatus includes a configuration component <NUM> which configures a new beam for the PDCCH of the first TRP based on the beam failure indication, e.g., as described in connection with <NUM> of <FIG>. The apparatus includes a new beam component <NUM> that receives a configuration of a new beam for the PDCCH of the second TRP in response to a beam failure of the PDCCH of the second TRP, the beam failure occurring before the new beam for the PDCCH of the first TRP is configured, e.g., as described in connection with <NUM> of <FIG>.

The processing system <NUM> may be coupled to a transceiver <NUM>. The transceiver <NUM> is coupled to one or more antennas <NUM>. The transceiver <NUM> provides a means for communicating with various other apparatus over a transmission medium. The transceiver <NUM> receives a signal from the one or more antennas <NUM>, extracts information from the received signal, and provides the extracted information to the processing system <NUM>, specifically the reception component <NUM>. In addition, the transceiver <NUM> receives information from the processing system <NUM>, specifically the transmission component <NUM>, and based on the received information, generates a signal to be applied to the one or more antennas <NUM>. The processing system <NUM> includes a processor <NUM> coupled to a computer-readable medium / memory <NUM>. The processor <NUM> is responsible for general processing, including the execution of software stored on the computer-readable medium / memory <NUM>. The software, when executed by the processor <NUM>, causes the processing system <NUM> to perform the various functions described supra for any particular apparatus. The computer-readable medium / memory <NUM> may also be used for storing data that is manipulated by the processor <NUM> when executing software. The processing system <NUM> further includes at least one of the components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The components may be software components running in the processor <NUM>, resident/stored in the computer readable medium / memory <NUM>, one or more hardware components coupled to the processor <NUM>, or some combination thereof. The processing system <NUM> may be a component of the base station <NUM> and may include the memory <NUM> and/or at least one of the TX processor <NUM>, the RX processor <NUM>, and the controller/processor <NUM>. Alternatively, the processing system <NUM> may be the entire base station (e.g., see <NUM> of <FIG>).

In one configuration, the apparatus <NUM>/<NUM>' for wireless communication includes means for transmitting data to a user equipment (UE) based on a physical downlink control channel (PDCCH) of the second TRP, wherein the PDCCH of the second TRP is transmitted to the UE over a separate beam than a PDCCH of the first TRP; means for receiving a beam failure indication from the UE in response to a beam failure of the PDCCH of the first TRP; and means for configuring a new beam for the PDCCH of the first TRP based on the beam failure indication. In one configuration, the apparatus may also include means for receiving a configuration of a new beam for the PDCCH of the second TRP in response to a beam failure of the PDCCH of the second TRP, the beam failure occurring before the new beam for the PDCCH of the first TRP is configured.

Claim 1:
A method (<NUM>) of wireless communication at a User Equipment, UE, comprising:
receiving (<NUM>) data from a first transmission reception point, TRP and a second TRP in a serving cell based on a physical downlink control channel, PDCCH, of the first TRP and the second TRP, the PDCCH of the first TRP and second TRP each received over separate beams;
detecting (<NUM>) beam failure of the PDCCH of the first TRP or a beam failure of the PDCCH of the second TRP; and
if a beam failure of the PDCCH of the first TRP is detected performing (<NUM>) beam failure recovery for the first TRP by transmitting a beam failure indication indicating a new beam for the PDCCH of the first TRP and if a beam failure of the PDCCH of the second TRP is detected performing (<NUM>) beam failure recovery for the second TRP by transmitting a beam failure indication indicating a new beam for the PDCCH of the second TRP.