Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may communicate with a network entity using one or more directional beams. The UE may detect a beam failure associated with at least one of the one or more directional beams, and the UE may calculate a duration between a detected beam failure and a subsequent random access occasion. The UE may transmit a beam failure recovery (BFR) message indicating the detected beam failure to the network entity or to a second UE based on whether the calculated duration satisfies a threshold duration. For example, the UE may transmit the BFR message to the second UE when the calculated duration is greater than or equal to the threshold duration. Alternatively, the UE may transmit the BFR message to the network entity when the calculated duration is less than the threshold duration.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a primary cell (PCell), a radio resource control (RRC) message that indicates an inter-cell mobility cell set and a measurement configuration. The UE may transmit, to the PCell, a measurement report that indicates one or more measurements of one or more cells indicated in the inter-cell mobility cell set, wherein the one or more measurements are derived based at least in part on the measurement configuration. The UE may receive, from the PCell, a joint cell activation and timing advance command medium access control control element (MAC-CE), wherein the joint cell activation and timing advance command MAC-CE indicates an activation of a new cell, of the one or more cells, and timing advance information associated with the new cell. Numerous other aspects are described.

Abstract: A method of wireless communication at a UE is disclosed herein. The method includes transmitting, at a first time instance, an indication of a first measurement on at least one DL-RS associated with a first cell, where the first cell is included in a L1 mobility configured cell set or a L2 mobility configured cell set. The method includes receiving, at a second time instance after the first time instance, an estimated TA associated with the first cell. The method includes performing a second measurement on the at least one DL-RS. The method includes accepting or rejecting the estimated TA for communication with the first cell based on at least one of the first measurement or the second measurement.

Abstract: An apparatus for wireless communication at a UE is provided. The apparatus is configured to receive a layer 1 (L1) or layer 2 (L2) mobility cell configuration for a set of cells for L1 or L2 inter-cell mobility. The set of cells include multiple cells, and each cell in the set of cells is able to be activated or deactivated for data and/or control transfer using L1 or L2 signaling. The apparatus is further configured to receive L1 or L2 signaling indicating multiple activated cells, and activate one or more cells in the multiple activated cells in the priority order for the data and/or control transfer using L1 or L2 signaling. The apparatus provides configuration, cell activation or deactivation in an optimized order, and associated signaling to enable L1/L2 mobility for more efficient and robust mobility management.

Abstract: A method of wireless communication at a UE is disclosed herein. The method includes receiving a L1 mobility cell configuration or a L2 mobility cell configuration for a set of cell groups, where each cell group in the set of cell groups includes a plurality of cells, where a first cell group in the set of cell groups is associated with a pTAG and a second cell group in the set of cell groups is associated with a sTAG, where the pTAG is associated with a first TA and the sTAG is associated with a second TA. The method further includes receiving L1 signaling or L2 signaling that associates the second cell group with the pTAG and the first cell group with the sTAG.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive configuration information indicative of one or more random access channel (RACH) resources for transmitting a RACH message to maintain timing advance (TA) associated with at least one deactivated cell corresponding to a TA group. The UE may transmit a RACH message to a network node corresponding to the at least one deactivated cell, wherein the RACH message is indicative of first TA information associated with the at least one deactivated cell. Numerous other aspects are described.

Abstract: This disclosure provides systems, methods, and apparatuses for supporting network transmissions using unicast sidelink communications. A base station (BS) may transmit a set of encoded packets to a number of user equipment (UEs) and receive feedback messages from the UEs that indicate sets of decoded packets. Based on the feedback messages, the BS may transmit an updated set of encoded packets based on a difference between the set of encoded packets and the union of decoded packets. The BS may transmit an instruction to a first UE to transmit a unicast sidelink communication to a second UE that includes a set of missed packets that includes one or more decoded packets that were decoded by the first UE but were not decoded by the second UE. The first UE may transmit the unicast sidelink communication to the second UE.

Abstract: A method for wireless communication by a user equipment (UE) includes receiving an indication of a mobility configured cell set having a number of cells. The method also includes receiving signaling to release a selected cell from the mobility configured cell set. The method further includes releasing the selected cell from the mobility configured cell set in response to receiving the signaling. In some aspects, releasing the selected cell comprises removing the selected cell from a carrier aggregation configuration. In other aspects, releasing the selected cell comprises removing a mobility configuration for the selected cell.

Abstract: Certain aspects of the present disclosure provide a method of wireless communication. An example method, performed at a first network entity, includes receiving a measurement report from a user equipment (UE) that supports dynamic mobility signaling via physical (PHY) layer or medium access control (MAC) layer signaling, wherein the measurement report includes at least one of PHY layer or MAC layer measurements, and transmitting the measurement report to a second network entity, based on an event trigger.

Abstract: A method of wireless communication at a UE is disclosed herein. The method includes receiving a L1 or L2 mobility cell configuration for a set of multiple cell groups comprising. Each cell group comprises multiple cells. Cell groups within the set of multiple cell groups are able to be activated or deactivated for L1 or L2 mobility. The method further includes receiving L1 or L2 signaling indicating a PCG from one or more activated cell groups, the PCG including a cell that serves as a SpCell.

Abstract: Methods, systems, and devices for wireless communications are described. In some systems, a network entity may configure a user equipment (UE) with a set of cells supporting Layer 1 (L1) mobility, Layer 2 (L2) mobility, or both for special cells (SpCells). The network entity may transmit a control signal, such as a medium access control (MAC) control element (CE) or a downlink control information (DCI) message, to the UE to update an SpCell. The control signal may include a cell identifier (ID) indicating which cell to set as the SpCell. Additionally, the control signal may include a transmission/reception point (TRP) ID indicating which TRP to set as the primary TRP (pTRP) for the SpCell. In response to the control signal, the UE may switch from a current SpCell to the cell indicated by the control signal and may communicate with the network via the pTRP of the new SpCell.

Abstract: Certain aspects of the present disclosure provide techniques for beam failure detection and recovery. An example method of wireless communication by a user equipment generally includes detecting a beam failure associated with a reference signal from a network entity and transmitting, to the network entity before initiating a beam failure recovery procedure, a request for a beam switch in response to the detected beam failure. The method also includes receiving, from the network entity, an indication to communicate via a beam in response to the request and communicating with the network entity via the beam based on the indication.

Abstract: Methods, systems, and devices for wireless communications are described. In some wireless communications systems, a base station may transmit sets of network coding encoded packets user equipments (UEs), and each set of network coding encoded packets may be associated with a redundancy overhead. The base station may dynamically identify the redundancy overhead for transmitting sets of network coding encoded packets to each UE based on a failure rate associated with a previous transmission of network coding encoded packets to that UE. For example, the base station may determine a failure rate associated with a transmission of a first set of network coding encoded packets and may identify a redundancy overhead associated with one or more second sets of network coding encoded packets based on the determined failure rate. In some cases, the base station may identify different redundancy overheads for transmissions of network coding encoded packets to different UEs.

Abstract: Methods, systems, and devices for wireless communications are described. A transmitter may identify a set of one or more packets for broadcast to a set of one or more user equipments (UEs) and transmit a set of one or more network encoded packets based on the set of one or more packets. The UEs may each rebroadcast one or more successfully received network encoded packets via sidelink communications. Each UE may report to the original transmitter via feedback indicating the one or more successfully received packets at each UE. The transmitter may generate an updated set of one or more network encoded packets based on the feedback from the UEs. The transmitter may continue to update and transmit the updated set of one or more network encoded packets based on feedback until the transmitter determines that each UE has recovered the set of one or more packets.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive configuration information corresponding to a Layer 1 or Layer 2 (L1/L2) inter-cell mobility operation associated with an L1/L2 mobility configured cell set. The UE may receive, based on the configuration information, a joint timing advance (TA) and cell activation medium access control control element (MAC CE), wherein the joint TA and cell activation MAC CE comprises a TA command and a cell activation command. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. The network may configure a set of cells including one or more active cells and one or more deactivated cell for a user equipment (UE). The network may indicate a triggering condition and communication resources for the UE to transmit a sounding reference signal (SRS) to the deactivated cell. Based on identifying that the triggering condition has been satisfied, the UE may transmit the SRS to the deactivated cell using the indicated communication resource. The network may decode the SRS and identify updated timing advance information. The network may indicate the updated timing advance information to the UE, and accordingly, when the deactivated cell is activated, the UE may have updated timing advance information to apply to uplink transmissions to the newly activated (previously deactivated) cell.

Abstract: Methods, systems, and devices for wireless communications are described. A network entity may configure one or more user equipments (UEs) with cell group configuration information for a single cell group or multiple cell groups. The configuration information may include parameters for each cell in the one or more cell groups. The configuration information may include a set of parameters for multiple candidate roles for each cell in the cell group. The network may then dynamically switch, update, or activate, cell groups, and may dynamically switch transmission reception points (TRPs) in a cell group from one role to another via dynamic signaling (e.g., level 1 (L1) or level 2 (L2) signaling). Additionally, or alternatively, the network may activate, deactivate, add, or remove, individual cells or cell groups from a set of configured cells via Ll or L2 signaling.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may monitor for reference signals from a first, reference cell and a second, deactivated cell, and the UE may report a timing difference between a first timing advance of the first cell and a second timing advance of the second cell. In some cases, the UE may report a timing difference periodically, and, in other cases, the UE may report a timing difference aperiodically. Once a network entity receives the timing difference, the network entity may determine the second timing difference for the UE to use to communicate with the second cell. The network entity may then signal the second timing difference to the UE when the second cell is activated for communications with the UE, and the UE may use the second timing advance to communicate with the second cell.

Abstract: Methods, systems, and devices for wireless communications are described. A network entity may configure a set of cells for communications with a user equipment (UE). The set of cells may include a first cell configured as a special cell (SpCell) and a second cell configured as a secondary cell (SCell). The network entity may indicate an SpCell configuration and an SCell configuration for communications with the first cell and an SCell configuration and a SpCell configuration for communications with the second cell. As such, if the network entity reconfigures the first cell as an SCell and reconfigures the second cell as a SpCell, the UE may communicate with the first cell using the SCell configuration, and the UE may communicate with the second cell using the SpCell configuration. The described techniques also include cell index management to support dynamic reconfiguration of a cell as a SpCell or an SCell.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, from a base station, control signaling indicating an activation of a beam failure detection (BFD) procedure for detecting beam failure on a per-beam basis for a set of beams. The UE may receive control signaling indicating BFD parameters for each beam to use in accordance with the BFD procedure. The UE may monitor for a set of reference signals via the set of beams and maintain, at a medium access control (MAC) layer, a separate beam failure indication (BFI) counter and a BFD timer for each beam. The MAC layer may receive the BFIs from a physical layer at the UE such that if the BFI counter for a beam satisfies a configured BFI threshold count before a configured BFD timing duration, the UE may transmit a beam failure recovery request to the base station for the beam.