Disclosed are a method, an apparatus, and a system for transmitting a signal using multiple carriers. In detail, provided are a wireless communication apparatus including a communication module; and a processor, wherein the processor obtains a common back-off counter for a carrier set on which data is to be transmitted, wherein the carrier set includes at least one component carrier, performs back-off of each of the component carriers using the obtained common back-off counter, and simultaneously transmits data through at least one component carrier in which the back-off is completed and a wireless communication method using the same.

An apparatus may determine whether to indicate a beam failure recovery request to a base station using a contention-free RACH procedure with a dedicated preamble when the UE is timing unsynchronized with the base station. The apparatus may perform, when the apparatus is timing unsynchronized with the base station, the contention-free RACH procedure with the dedicated preamble to indicate the beam failure recovery request when the beam failure recovery request is determined to be indicated to the base station using the contention-free RACH procedure with the dedicated preamble. The apparatus may perform, when the apparatus is timing unsynchronized with the base station, a contention-based RACH procedure to indicate the beam failure recovery request when the beam failure recovery request is undetermined to be sent to the base station using the contention-free RACH procedure with the dedicated preamble.

A method, a terminal, and a base station for asynchronous uplink transmission are provided, to reduce an uplink data transmission latency and signaling overheads when a terminal and a base station are in out-of-synchronization state. The method includes: obtaining asynchronous transmission parameter information that is the same as that of a base station, where asynchronous transmission parameter information includes physical resource information, modulation and coding scheme information, and physical resource frame format information, and the physical resource frame format information includes length information of a physical resource frame; determining a length of an asynchronous transmission frame according to the physical resource frame format information; and sending first uplink information to the base station according to the asynchronous transmission parameter information by using the asynchronous transmission frame.

Techniques, apparatus and methods are disclosed that enable reduced signaling overhead in a fifth generation (5G) wireless system. The system includes support for asynchronous uplink transmission, resource pool configuration, acknowledgement response and retransmission. For example, in a Type-1 transmission scheme, a user equipment (UE) selects one resource within the resource pool and transmits data in the uplink on the selected resource. In a Type-2 transmission scheme, a UE selects one resource within a scheduling request (SR) region in the resource pool, transmits the SR for the resource which contains the resource allocation for data transmission, and transmits the uplink data on the resource which is indicated in the SR information. In a Type-3 transmission scheme, a UE selects a resource within the SR region, transmits the SR on the selected resource with information on the resource selected for subsequent data transmission and transmits on the indicated resource if it receives an acknowledgment, in response to its transmitted SR.

An apparatus may determine whether to indicate a beam failure recovery request to a base station using a contention-free RACH procedure with a dedicated preamble when the UE is timing unsynchronized with the base station. The apparatus may perform, when the apparatus is timing unsynchronized with the base station, the contention-free RACH procedure with the dedicated preamble to indicate the beam failure recovery request when the beam failure recovery request is determined to be indicated to the base station using the contention-free RACH procedure with the dedicated preamble. The apparatus may perform, when the apparatus is timing unsynchronized with the base station, a contention-based RACH procedure to indicate the beam failure recovery request when the beam failure recovery request is undetermined to be sent to the base station using the contention-free RACH procedure with the dedicated preamble.

Certain aspects of the present disclosure provide techniques for supporting UL-based mobility without DL zone signals. A DL zone signal may refer to a zone synchronization signal or a zone measurement reference signal. As described herein, a UE may perform certain operations upon power-up or RLF recovery, perform operations in each DRx cycle, and/or perform inter-zone handovers without relying on DL zone signals. Thus, aspects create a more user-centric environment and reduce and/or avoid transmission DL zone signals.

The present disclosure provides a method and an apparatus for random access in a wireless communication system, as well as a user terminal. The method includes: receiving indication information transmitted from a radio base station, the indication information instructing a user terminal to initiate a random access; determining a target Physical Random Access Channel (PRACH) resource from available resources based on a current coverage level and resource information carried in the indication information, the target PRACH resource being used for transmitting a PRACH signal for initiating the random access; and re-determining, in response to a failure to initiate the random access over the target PRACH resource, the target PRACH resource from the available resources based on an updated coverage level and the resource information, and transmitting the PRACH signal over the re-determined target PRACH resource. The present disclosure can solve the technical problem in the related art associated with low success rate of random accesses initiated by radio base stations.

Disclosed are a method, an apparatus, and a system for transmitting a signal using multiple carriers. In detail, provided are a wireless communication apparatus including a communication module; and a processor, wherein the processor obtains a common back-off counter for a carrier set on which data is to be transmitted, wherein the carrier set includes at least one component carrier, performs back-off of each of the component carriers using the obtained common back-off counter, and simultaneously transmits data through at least one component carrier in which the back-off is completed and a wireless communication method using the same.

In a communications system which complies with LTE including a base station which transmits data by using an OFDM (Orthogonal Frequency Division Multiplexing) method as a downlink access method, and a mobile terminal, in a case in which an uplink scheduling request signal is transmitted by using an S-RACH when an Ack/Nack signal is being transmitted by using an Ack/Nack exclusive channel, the transmission of the Ack/Nack signal is stopped while the uplink scheduling request signal is transmitted.

The present disclosure provides an SP-ID indication method, an SP-ID indication device, a UE and an access device. The SP-ID indication method includes: transmitting, by a UE, an access request message to an access device through a PRACH, the access request message being at least used to indicate the quantity of PSP-IDs to be transmitted by the UE; and receiving, by the UE, resource information about uplink resources from the access device, the uplink resources being selected by the access device in accordance with the quantity of the PSP-IDs to be transmitted by the UE and used to transmit the PSP-IDs to be transmitted by the UE.