A wireless communication device that transmits data to another wireless communication device that performs wireless connection using a packet including a transmission number, the wireless communication device includes, a controller configured to classify the data as first data when a transmission condition indicating a condition related to transmission of the data is a first transmission condition and classifies the data as second data when the transmission condition of the data is a second transmission condition different from the first transmission condition, and a transmitter configured to transmit the data in a first transmission mode in a layer related to the wireless connection when the data is the first data and transmits the data in a second transmission mode in a layer related to the wireless connection when the second data is second data.

The present disclosure provide a method and terminal for counting preamble retransmission in a random access procedure. The method includes: in a random access procedure, when detecting that no Random Access Response (RAR) is received or contention resolution fails, counting a number of times of retransmission of a preamble and/or a number of times of power ramping of transmission of the preamble according to a configured counter/counters.

The present disclosure provide a method and terminal for counting preamble retransmission in a random access procedure. The method includes: in a random access procedure, when detecting that no Random Access Response (RAR) is received or contention resolution fails, counting a number of times of retransmission of a preamble and/or a number of times of power ramping of transmission of the preamble according to a configured counter/counters.

A method performed by a user equipment (UE) in a wireless communication system, the method including: selecting to create a configured sidelink grant corresponding to transmissions of at least one media access control (MAC) protocol data unit (PDU); and triggering a transmission carrier selection procedure based on (i) data being available in a sidelink traffic channel (STCH) associated with one or more carriers, and (ii) there being no configured sidelink grant on any carrier, among the one or more carriers, that is allowed for the STCH.

A method performed by a user equipment (UE) in a wireless communication system, the method including: selecting to create a configured sidelink grant corresponding to transmissions of at least one media access control (MAC) protocol data unit (PDU); and triggering a transmission carrier selection procedure based on (i) data being available in a sidelink traffic channel (STCH) associated with one or more carriers, and (ii) there being no configured sidelink grant on any carrier, among the one or more carriers, that is allowed for the STCH.

A control method for User Equipment (UE) comprising: performing communication with a master cell group (MCG) and a secondary cell group (SCG); detecting whether a failure occurred in the MCG transmission; if it is detected that the failure has occurred in the MCG transmission, executing an MCG failure processing operation; and sending a message to a base station, the message indicating information related to the failure.

A control method for User Equipment (UE) comprising: performing communication with a master cell group (MCG) and a secondary cell group (SCG); detecting whether a failure occurred in the MCG transmission; if it is detected that the failure has occurred in the MCG transmission, executing an MCG failure processing operation; and sending a message to a base station, the message indicating information related to the failure.

An apparatus and method for transmitting data of vehicle communication (V2X) services and a communication system. The apparatus includes: a first generating unit configured in a media access control (MAC) layer of the terminal equipment and configured to generate at least one protocol data unit (PDU) in a mode identical to a transmission mode to which a service data unit (SDU) contained in a PDU corresponds; and a first transmitting unit configured in the MAC layer and configured to transmit the PDU to a physical layer of the terminal equipment, and notify the transmission mode to which the PDU corresponds to the physical layer. This disclosure facilitates the physical layer to transmit data in a corresponding transmission mode. The terminal equipment may determine the transmission mode or set the transmission mode according to the indication information, and layers of the terminal equipment perform corresponding processing.

An apparatus and method for transmitting data of vehicle communication (V2X) services and a communication system. The apparatus includes: a first generating unit configured in a media access control (MAC) layer of the terminal equipment and configured to generate at least one protocol data unit (PDU) in a mode identical to a transmission mode to which a service data unit (SDU) contained in a PDU corresponds; and a first transmitting unit configured in the MAC layer and configured to transmit the PDU to a physical layer of the terminal equipment, and notify the transmission mode to which the PDU corresponds to the physical layer. This disclosure facilitates the physical layer to transmit data in a corresponding transmission mode. The terminal equipment may determine the transmission mode or set the transmission mode according to the indication information, and layers of the terminal equipment perform corresponding processing.

The present disclosure relates to transmission prioritization in wireless communications. According to an embodiment of the present disclosure, a method performed by a wireless device in a wireless communication system comprises: configuring a threshold; creating a media access control (MAC) protocol data unit (MAC PDU) for sidelink comprising a MAC control element (CE); setting a priority value to the MAC CE; identifying a transmission of the MAC PDU for sidelink and an uplink transmission to be performed; determining that the transmission of the MAC PDU for sidelink and the uplink transmission are not able to be performed simultaneously; determining that the priority value of the MAC CE is lower than the threshold; prioritizing the transmission of the MAC PDU for sidelink over the uplink transmission; and performing the transmission of the MAC PDU for sidelink that is prioritized over the UL transmission.