The present application provides a method for determining a random access resource by a terminal in a wireless communication system, the method comprising: receiving, from a base station, configuration information corresponding to a synchronization signal block (SSB) including a SSB index, a random access preamble index and a random access channel mask index; determining a random access resource based on the SSB index and the random access channel mask index; determining a random access preamble based on the random access preamble index; and transmitting, to the base station, the random access preamble on the random access resource.

Certain aspects of the present disclosure provide techniques for cross-carrier retransmission. A method that may be performed by a user equipment (UE) includes monitoring for an initial transmission of data from a network on a first entity, generating a negative acknowledgement message indicating that decoding of the initial transmission of the data was unsuccessful, transmitting the negative acknowledgement message, and monitoring for a retransmission of the data on a second entity after the transmission of the negative acknowledgement message, the second entity being different than the first entity.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a network node, downlink control information (DCI) that includes a request for a dropped hybrid automatic repeat request (HARQ) codebook, wherein the DCI indicates a codebook identifier (ID) associated with the dropped HARQ codebook. The UE may transmit, to the network node, the dropped HARQ codebook based at least in part on the codebook ID associated with the dropped HARQ codebook, as indicated in the DCI. Numerous other aspects are described.

Disclosed is the radio (wireless) communication system providing a radio communication service and the terminal, and more particularly, to a method of an uplink HARQ (Hybrid Automatic Repeat reQuest) operation at an expiry of time alignment timer in an Evolved Universal Mobile Telecommunications System (E-UMTS) evolved from the Universal Mobile Telecommunications System (UMTS) or a Long Term Evolution (LTE) system.

Techniques and apparatus for hybrid automatic retransmission request (HARQ) acknowledgement (ACK) bundling in half duplex frequency division duplexing (HD-FDD) systems are provided. One technique includes determining ACK parameter(s) to be used for acknowledging a bundled transmission that includes instance(s) of a channel across subframe(s). An indication of the ACK parameter(s) is signaled to a user equipment (UE). The ACK parameter(s) include a first ACK parameter that conveys a size of the bundled transmission and a second ACK parameter that conveys an amount of time for the UE to delay acknowledging a data transmission in an instance of the channel after receiving the data transmission. The UE may acknowledge the bundled transmission in accordance with the ACK parameter(s).

Methods and apparatuses are provided for generating a protocol data unit (PDU). An apparatus may comprise a processor configured to provide a medium access control (MAC) entity and a segmentation entity. The MAC entity may indicate an amount of data associated with the segmentation entity to be multiplexed by the MAC entity. The segmentation entity may segment, based on the indicated amount of data, a service data unit (SDU) into a segment, and the MAC entity may multiplex the segment into a MAC protocol data unit (PDU). The MAC PDU may include a field that indicates whether the segment is included and whether the segment is a last segment. The apparatus may further comprise a transmitter configured to transmit the MAC PDU.

Methods and apparatuses are provided in which it is determined to transmit a physical uplink control channel (PUCCH) with a positive scheduling request (SR) and one or more hybrid automatic repeat request acknowledgement (HARQ-ACK) information bits in a PUCCH resource of a PUCCH format 0. A value mcs for a cyclic shift for the PUCCH format 0 is identified based on the positive SR and the one or more HARQ-ACK information bits. The positive SR and the one or more HARQ-ACK information bits are transmitted to the base station in the PUCCH resource of the PUCCH format 0, based on the value mcs.

A method by a user equipment (UE) includes receiving a radio resource control (RRC) configuration carrying a configuration for a first downlink (DL) channel and an uplink (UL) channel, receiving the first DL channel and a second DL channel, and canceling the UL channel when a timing condition between the first DL channel and the second DL channel is satisfied.

A method and apparatus for sending uplink control information by a multi-mode wireless transmit/receive unit (WTRU) capable of operating on multiple component carriers of a plurality of radio access technologies (RATs) for multi-RAT operation are disclosed. The WTRU may generate uplink control information (UCI) pertaining to a first RAT and a second RAT, wherein the UCI may include a first plurality of hybrid automatic repeat request acknowledgements (HARQ-ACKs) pertaining to a plurality of downlink (DL) transmissions of the first RAT and a second plurality of HARQ-ACKs pertaining to a plurality of DL transmissions of the second RAT. The WTRU may multiplex at least part of the generated UCI pertaining to the first RAT and at least part of the generated UCI pertaining to the second RAT onto a physical channel on a component carrier of the second RAT.

A wireless device receives a downlink control information (DCI) comprising a first field indicating a transition of a cell to a dormant state and a second field indicating a hybrid automatic repeat request (HARQ) feedback timing. The wireless device transmits, in response to the DCI indicating the transition and via a physical uplink control channel resource, a positive acknowledgement of a reception of the DCI at a time interval based on the HARQ feedback timing.