Methods, systems, and devices for updating timing advance values for deactivated cells are described. A user equipment (UE) may transmit, to a first cell that is deactivated, a random access message for a timing advance probing procedure. The UE may transmit the random access message to the first cell. In some examples, the UE may receive, from a second cell, an activation command that activates the first cell and an indication of a timing advance value for the first cell generated based on the random access message. In other examples, the UE may monitor for a random access response (RAR) message from the first cell, the RAR message including an activation command that activates the first cell and an indication of a timing advance value generated based on the random access message. The UE may communicate with the first cell based on the activation command and the timing advance value.

The present disclosure relates to methods and devices for wireless communication at an apparatus, e.g., a UE or a base station. The base station may be configured to configure one or more RACH resources for a FD RACH configuration and transmit, to at least one UE, an indication of the one or more RACH resources configured for the FD RACH configuration. The UE may be configured to receive the indication of the FD RACH configuration for the one or more RACH resources. The UE may further be configured to select, based on the received indication, at least one RACH resource of the one or more RACH resources for the FD RACH configuration and transmit, to the first base station via the selected at least one RACH resource, at least one message of a RACH procedure based on the FD RACH configuration.

The present disclosure relates to methods and devices for wireless communication at an apparatus, e.g., a UE or a base station. The base station may be configured to configure one or more RACH resources for a FD RACH configuration and transmit, to at least one UE, an indication of the one or more RACH resources configured for the FD RACH configuration. The UE may be configured to receive the indication of the FD RACH configuration for the one or more RACH resources. The UE may further be configured to select, based on the received indication, at least one RACH resource of the one or more RACH resources for the FD RACH configuration and transmit, to the first base station via the selected at least one RACH resource, at least one message of a RACH procedure based on the FD RACH configuration.

A user equipment (UE), baseband processor or other network device (e.g., base station, next generation NodeB, etc.) can operate to configure a hand over (HO) or a primary secondary cell (PSCell) addition based on a channel state information reference signal (CSI-RS) based contention free random access (CFRA) procedure. A CSI-RS rough timing of a CSI-RS position can be determined based on a synchronization signal block (SSB) associated with a CSI-RS or a serving cell timing. A CFRA transmit timing can be determined based on the CSI-RS rough timing or a CSI-RS fine timing that is derived from a timing and frequency (T/F) tracking operation on the CSI-RS. Reference signal receive power (RSRP) measurement(s) can be made on the CSI-RS for performing the CSI-RS based CFRA procedure with transmissions according to the CSI-RS transmit timing of the CSI-RS that satisfies an RSRP threshold.

A user equipment (UE), baseband processor or other network device (e.g., base station, next generation NodeB, etc.) can operate to configure a hand over (HO) or a primary secondary cell (PSCell) addition based on a channel state information reference signal (CSI-RS) based contention free random access (CFRA) procedure. A CSI-RS rough timing of a CSI-RS position can be determined based on a synchronization signal block (SSB) associated with a CSI-RS or a serving cell timing. A CFRA transmit timing can be determined based on the CSI-RS rough timing or a CSI-RS fine timing that is derived from a timing and frequency (T/F) tracking operation on the CSI-RS. Reference signal receive power (RSRP) measurement(s) can be made on the CSI-RS for performing the CSI-RS based CFRA procedure with transmissions according to the CSI-RS transmit timing of the CSI-RS that satisfies an RSRP threshold.

Systems and methods for determining a timing of a random access channel (RACH) occasion (RO) used to transmit a contention free random access (CFRA) preamble triggered by the receipt of an physical downlink control channel (PDCCH) order in a PDCCH are disclosed herein. A user equipment (UE) receives the PDCCH order and determines a timing offset value between the RO and a signal (e.g., a synchronization signal block (SSB), the PDCCH, a reference signal, etc.) to be used as a timing source. The UE also determines the arrival time of the signal to be used at the timing source. The UE then determines a time of the RO (during which the CFRA preamble will be transmitted) according to the arrival time and the timing offset value. Timing advance (TA) value(s) may also be accounted for as part of such a determination.

Systems and methods for determining a timing of a random access channel (RACH) occasion (RO) used to transmit a contention free random access (CFRA) preamble triggered by the receipt of an physical downlink control channel (PDCCH) order in a PDCCH are disclosed herein. A user equipment (UE) receives the PDCCH order and determines a timing offset value between the RO and a signal (e.g., a synchronization signal block (SSB), the PDCCH, a reference signal, etc.) to be used as a timing source. The UE also determines the arrival time of the signal to be used at the timing source. The UE then determines a time of the RO (during which the CFRA preamble will be transmitted) according to the arrival time and the timing offset value. Timing advance (TA) value(s) may also be accounted for as part of such a determination.

This application pertains to the field of communication technologies and discloses a random access resource selection method and apparatus, a random access resource configuration method and apparatus, a terminal, and a network side device. The random access resource selection method is performed by a terminal and includes: receiving configuration information sent by a network side device, where the configuration information is used to indicate an association relationship between a random access resource configured by the network side device and a first characteristic; and selecting a random access resource based on the configuration information and a second characteristic supported by the terminal, where the random access resource includes at least one of the following: a downlink reference signal, a carrier, a bandwidth part, a random access type, a random access preamble, a random access preamble group, and a random access occasion.

This application pertains to the field of communication technologies and discloses a random access resource selection method and apparatus, a random access resource configuration method and apparatus, a terminal, and a network side device. The random access resource selection method is performed by a terminal and includes: receiving configuration information sent by a network side device, where the configuration information is used to indicate an association relationship between a random access resource configured by the network side device and a first characteristic; and selecting a random access resource based on the configuration information and a second characteristic supported by the terminal, where the random access resource includes at least one of the following: a downlink reference signal, a carrier, a bandwidth part, a random access type, a random access preamble, a random access preamble group, and a random access occasion.

Disclosed is a user equipment (UE) configured to perform beam failure recovery with uplink antenna panel selection. In some embodiments, the UE determines a first UE antenna panel corresponding to a candidate beam detection (CBD) reference signal (RS); reports to a gNB a beam failure recovery request (BFRQ), the BFRQ including UE antenna panel information for the first UE antenna panel; and after receiving from the gNB a response to the BFRQ, changes from a second UE antenna panel to the first UE antenna panel and corresponding configuration for uplink transmission.