Provided in the present disclosure are a spectrum management device and method, a geographic location database, a coexistence discovery device, and subsystems for use in a radio communication system comprising a main system and subsystems. The spectrum management device comprises: a processing circuit, which is configured to: acquire spectrum usage information and spectrum transition capability information of subsystems managed by the spectrum management device, the spectrum usage information corresponding to information related to used spectrums assigned to and used by each subsystem, the spectrum transition capability information corresponding to information related to whether the subsystems support a spectrum transition operation, and an transition of the spectrums of the subsystems managed by the spectrum management device is determined on the basis of the spectrum usage information and the spectrum transition capability information, thus the interference caused by the subsystems as a result of spectrum usage to the main system is limited within a permissible range of the main system. The spectrum management device and method, the geographic location database, the coexistence discovery device, and the subsystems of the present disclosure achieve highly efficient use of spectrum resources.

Provided in the present disclosure are a spectrum management device and method, a geographic location database, a coexistence discovery device, and subsystems for use in a radio communication system comprising a main system and subsystems. The spectrum management device comprises: a processing circuit, which is configured to: acquire spectrum usage information and spectrum transition capability information of subsystems managed by the spectrum management device, the spectrum usage information corresponding to information related to used spectrums assigned to and used by each subsystem, the spectrum transition capability information corresponding to information related to whether the subsystems support a spectrum transition operation, and an transition of the spectrums of the subsystems managed by the spectrum management device is determined on the basis of the spectrum usage information and the spectrum transition capability information, thus the interference caused by the subsystems as a result of spectrum usage to the main system is limited within a permissible range of the main system. The spectrum management device and method, the geographic location database, the coexistence discovery device, and the subsystems of the present disclosure achieve highly efficient use of spectrum resources.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify a gap period following a downlink portion of a time division duplexing (TDD) frame. The UE may selectively perform, based at least in part on the gap period, a clear channel assessment (CCA) on a channel of a radio frequency spectrum band. The UE may transmit at least one of a sounding reference signal (SRS) or a physical random access channel (PRACH) preamble in a set of initial symbols of an uplink portion of the TDD frame following the gap period, wherein the SRS or PRACH preamble is frequency-domain multiplexed during the set of initial symbols with one or more of: a demodulation reference signal (DMRS), an uplink data transmission, an uplink control transmission, or a random access transmission.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify a gap period following a downlink portion of a time division duplexing (TDD) frame. The UE may selectively perform, based at least in part on the gap period, a clear channel assessment (CCA) on a channel of a radio frequency spectrum band. The UE may transmit at least one of a sounding reference signal (SRS) or a physical random access channel (PRACH) preamble in a set of initial symbols of an uplink portion of the TDD frame following the gap period, wherein the SRS or PRACH preamble is frequency-domain multiplexed during the set of initial symbols with one or more of: a demodulation reference signal (DMRS), an uplink data transmission, an uplink control transmission, or a random access transmission.

A user equipment that includes a radio transceiver that performs wireless communication in an unlicensed band, and circuitry that performs RLM using downlink physical signals, measures a radio link quality, evaluates the radio link quality against thresholds Qout and Qin, indicates out-of-sync to higher layers from a physical layer, indicates in-sync to the higher layers from the physical layer, starts a first timer when the out-of-sync is consecutively indicated to the higher layers from the physical layer, and determines that a radio link failure occurs in a case where the first timer expires without consecutive in-sync indications, and the first timer is different from a second timer used to determine whether a radio link failure occurs in a wireless communication in one or more serving cells in a licensed band.

A user equipment that includes a radio transceiver that performs wireless communication in an unlicensed band, and circuitry that performs RLM using downlink physical signals, measures a radio link quality, evaluates the radio link quality against thresholds Qout and Qin, indicates out-of-sync to higher layers from a physical layer, indicates in-sync to the higher layers from the physical layer, starts a first timer when the out-of-sync is consecutively indicated to the higher layers from the physical layer, and determines that a radio link failure occurs in a case where the first timer expires without consecutive in-sync indications, and the first timer is different from a second timer used to determine whether a radio link failure occurs in a wireless communication in one or more serving cells in a licensed band.

Provided are a method and an apparatus for transmitting an uplink channel in an unlicensed band. The method includes configuring an interface for an uplink channel based on interlacing information determined according to subcarrier spacing (SCS) of an unlicensed band; and transmitting the uplink channel by applying the interlace.

A communication apparatus, terminal apparatus, system and method are provided for performing wireless communication. The communication apparatus supports a plurality of component carriers, wherein one of the plurality of component carriers is designated as a current primary component and at least one of the plurality of component carriers is designated as a current secondary component carrier providing at least downlink communication. The communication apparatus comprises control circuitry for controlling a component carrier testing procedure for one or more component carriers. The testing procedure comprises, for each component carrier: establishing an uplink connection from the terminal apparatus to the communication apparatus using the component carrier; and determining a quality of the uplink connection for the component carrier. The control circuitry is responsive to completion of the testing procedure to designate an updated primary component carrier on the basis of the qualities of the uplink connections determined for the component carriers.

A first group embodiments provide a method performed by a network node (NN) in a wireless network comprising responsive to a DL data intended for a user equipment (UE), transmitting a first short signal burst to the UE over a channel using a directional beam, and based on detecting a first response to the first short signal burst from the UE indicating that the channel is available, transmitting at least a portion of the DL data to the UE over the channel using the directional beam. A second group embodiments provide a method performed by a NN comprising determining availability of a channel between the network node and the UE using a directional beam, based on determining that the channel is available, transmitting a first resource grant for transmission of a UL data by the UE, and receiving the UL data from the UE over the channel using the directional beam.

A base station according to an embodiment of the present disclosure includes a generation unit (35) that generates a beacon including switching information (41) indicating whether to cooperatively use a frequency channel and a transmission unit (32) that transmits the beacon.