A communication system, a data transmission method and a base station thereof are provided. The communication system includes a first base station and a second base station. The first base station includes a physical layer unit, a MAC layer unit and a PDCP layer unit. The physical layer unit is configured to transmit with a user equipment through a transmission channel. The MAC layer unit is configured to determine whether a retransmission ratio of the transmission channel is higher than a first threshold and to determine whether a transmission speed of the transmission channel is lower than a second threshold. If the retransmission ratio is higher than the first threshold and/or the transmission speed is lower than the second threshold, the first base station copy a packet and then transmits the copied packet to the second base station which accordingly transmits the copied packet to the user equipment.

A communication system, a data transmission method and a base station thereof are provided. The communication system includes a first base station and a second base station. The first base station includes a physical layer unit, a MAC layer unit and a PDCP layer unit. The physical layer unit is configured to transmit with a user equipment through a transmission channel. The MAC layer unit is configured to determine whether a retransmission ratio of the transmission channel is higher than a first threshold and to determine whether a transmission speed of the transmission channel is lower than a second threshold. If the retransmission ratio is higher than the first threshold and/or the transmission speed is lower than the second threshold, the first base station copy a packet and then transmits the copied packet to the second base station which accordingly transmits the copied packet to the user equipment.

According to an embodiment of the disclosure, provided are an operation method of a first user equipment (UE), and the first UE, in a wireless communication system. The operation method of the first UE includes: transmitting, to a second UE, UE sidelink capability information including out-of-order delivery capability information of a packet data convergence protocol (PDCP) layer of the first UE; and receiving, from the second UE, out-of-order delivery configuration information configured for a sidelink radio bearer, based on the out-of-order delivery capability information of the PDCP layer of the first UE. Also, the operation method of the first UE further includes processing sidelink data received from the second UE, based on the out-of-order delivery configuration information.

The UE includes higher layer circuitry configured to receive information including more than one transmission configuration indication (TCI) states. The UE also includes medium access control (MAC) circuitry configured to receive a first MAC control element (CE) and a second MAC CE. The UE further includes reception circuitry configured to receive first downlink control information (DCI) on a physical downlink control channel (PDCCH), and second DCI on a PDCCH. The first MAC CE selects one of more TCI states from the more than one TCI states and maps the selected one or more TCI states to the codepoints of a TCI field in the second DCI. The second MAC CE selects one of more TCI states from the more than one TCI states and maps the selected one or more TCI states to the codepoints of the TCI field in the second DCI.

Methods, systems, and devices for wireless communications are described. In some cases, a user equipment (UE) may transmit, to a base station, a report indicating a capability of the UE to support symbol level quantization, slot level quantization, or both. The UE may identify that the UE is to utilize the slot level quantization For instance, the UE may receive control signaling indicating that the UE is to utilize slot level quantization and may perform the identifying based on receiving the control signaling The UE may receive a first transmission via a first channel and may communicate, responsive to receiving the first transmission, a second transmission via a second channel at a quantized start timing determined in accordance with the slot level quantization.

A communication method includes determining, by a terminal side device, that a consistent uplink listen before talk (LBT) failure occurs in a first bandwidth part (BWP) of a cell. The communication method also includes canceling, by the terminal side device, a consistent uplink LBT failure status of the cell in response to a determination by the terminal side device to switch to a second BWP of the cell.

A data transmission method is provided. The method comprises: when a replication transmission state is deactivated, if a first condition is satisfied, a sending device transmits data on the basis of a separation transmission mode, or the sending device delivers the data to a main path or a separation auxiliary path. Also disclosed in the present application are another data transmission method, a sending device, and a storage medium.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may receive protocol data units (PDUs) in multiple TTIs (e.g., slots). The wireless communication device may generate, for each TTI of the multiple TTIs, a descriptor that identifies serial numbers (SNs) of PDUs that are received in the TTI. The wireless communication device may aggregate the descriptors for the multiple TTIs into an aggregated descriptor that identifies the SNs of the PDUs across the multiple TTIs. The wireless communication device may process the PDUs received in the multiple TTIs based at least in part on the aggregated descriptor. Numerous other aspects are described.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may receive protocol data units (PDUs) in multiple TTIs (e.g., slots). The wireless communication device may generate, for each TTI of the multiple TTIs, a descriptor that identifies serial numbers (SNs) of PDUs that are received in the TTI. The wireless communication device may aggregate the descriptors for the multiple TTIs into an aggregated descriptor that identifies the SNs of the PDUs across the multiple TTIs. The wireless communication device may process the PDUs received in the multiple TTIs based at least in part on the aggregated descriptor. Numerous other aspects are described.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may identify a base station capable of performing medium access control (MAC) based transmission configuration indication (TCI) switching. The UE may deactivate an autonomous beam switching mode based at least in part on the base station being capable of performing MAC based TCI switching. Numerous other aspects are described.