The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present disclosure provides method and apparatus of performing random access procedure.

Apparatuses and methods supporting uplink transmissions are disclosed. A method includes receiving signaling including information indicating a primary cell and at least one non-primary cell, receiving a message with scheduling information indicating an allocation of uplink resources and a HARQ process ID, and transmitting to at least the one non-primary cell an uplink transmission using a HARQ process indicated by the HARQ process ID and the allocation of uplink resources. Another method includes transmitting signaling including information indicating a primary cell and at least one non-primary cell, transmitting a message with scheduling information indicating an allocation of uplink resources and a HARQ process ID to a wireless transmit/receive unit (WTRU), and receiving an uplink transmission using a HARQ process indicated by the HARQ process ID and the allocation of uplink resources on at least the one non-primary cell.

Apparatuses and methods supporting uplink transmissions are disclosed. A method includes receiving signaling including information indicating a primary cell and at least one non-primary cell, receiving a message with scheduling information indicating an allocation of uplink resources and a HARQ process ID, and transmitting to at least the one non-primary cell an uplink transmission using a HARQ process indicated by the HARQ process ID and the allocation of uplink resources. Another method includes transmitting signaling including information indicating a primary cell and at least one non-primary cell, transmitting a message with scheduling information indicating an allocation of uplink resources and a HARQ process ID to a wireless transmit/receive unit (WTRU), and receiving an uplink transmission using a HARQ process indicated by the HARQ process ID and the allocation of uplink resources on at least the one non-primary cell.

In the present invention, a user equipment (UE) receives an UL grant that can be used while the UE is not in RRC_CONNECTED state. If the UE receives a message indicating to leave RRC_CONNECTED state, the UE starts a time alignment timer (I-TAT) when the UE leaves RRC_CONNECTED state. The UE transmits UL data using the UL grant if the UL data becomes available for transmission when the UE is not in RRC_CONNECTED state and if the I-TAT is running.

A user apparatus receives an instruction to execute a random access procedure from a base station apparatus and includes a reception unit that receives first information specifying an available random access channel from the base station apparatus; a control unit that identifies, on the basis of the first information, a resource of the available random access channel in a time domain or a frequency domain; and a transmission unit that transmits a random access preamble using the identified resource.

A user apparatus receives an instruction to execute a random access procedure from a base station apparatus and includes a reception unit that receives first information specifying an available random access channel from the base station apparatus; a control unit that identifies, on the basis of the first information, a resource of the available random access channel in a time domain or a frequency domain; and a transmission unit that transmits a random access preamble using the identified resource.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may detect a beam failure event associated with the UE. The UE may detect a first condition of the UE. The UE may perform one or more actions associated with beam failure recovery based at least in part on a measure of similarity between the first condition of the UE and a second condition of the UE associated with a past beam failure event. Numerous other aspects are described.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may detect a beam failure event associated with the UE. The UE may detect a first condition of the UE. The UE may perform one or more actions associated with beam failure recovery based at least in part on a measure of similarity between the first condition of the UE and a second condition of the UE associated with a past beam failure event. Numerous other aspects are described.

Methods, systems, and devices for wireless communications are described. In some examples, a base station may recover a UE from a Msg3 failure during an RA procedure. During the RA procedure, the base station may transmit a RAR message to the UE and in response to the RAR message the UE may transmit an uplink message (e.g., Msg3) to the base station over a first resource indicated in the RAR message. If the base station fails to decode or receive the uplink message over the first resource, the base station may transmit a grant to the UE indicating a second resource for retransmitting the uplink message and the UE may retransmit uplink message to the base station according to the grant.

Methods, systems, and devices for wireless communications are described. In some examples, a base station may recover a UE from a Msg3 failure during an RA procedure. During the RA procedure, the base station may transmit a RAR message to the UE and in response to the RAR message the UE may transmit an uplink message (e.g., Msg3) to the base station over a first resource indicated in the RAR message. If the base station fails to decode or receive the uplink message over the first resource, the base station may transmit a grant to the UE indicating a second resource for retransmitting the uplink message and the UE may retransmit uplink message to the base station according to the grant.