Abstract: Methods and apparatus are described. A method, implemented in a wireless transmit/receive unit (WTRU) includes monitoring a first control channel search space (SS) associated with a first normal beam set comprising a first beam set. The WTRU initiates extended monitoring and monitors, subsequent to a trigger based on a measurement by the WTRU, a control channel SS associated with an extended beam set comprising the first beam set and one or more additional beam sets. The WTRU determines a second beam set from the extended beam set. The determination is based on a received control channel beam switch command or based on a control channel SS in which a beam switch command is received. The WTRU monitors a second control channel SS associated with a second normal beam set comprising the determined second beam set.

Abstract: A method performed by a base station may include transmitting a configuration message including at least information indicating a subset of a plurality of transmit beams to be used for transmitting a set of synchronization signals. The set of synchronization signals including a primary synchronization signal and a secondary synchronization signal may be transmitted. A random access channel (RACH) transmission may be received using a receive beam associated with one of the subset of the plurality of transmit beams used by the base station to transmit the set of synchronization signals. The transmitted set of synchronization signals transmitted may have a signal quality above a signal quality threshold. A reference signal may be transmitted along with a physical broadcast channel (PBCH) transmission. The reference signal may have a sequence derived from a beam index associated with the one of the subset of the plurality of transmit beams.

Abstract: Systems, procedures, and instrumentalities are disclosed for distributed control in wireless systems, such as 5G flexible radio access technology (RAT) (5gFLEX). Example procedures are provided for WTRU and network operation associated with a distributed control plane architecture, connectionless data transfer and dedicated system information acquisition. Distributed control may be provided, for example, by replicating a plurality of access control functions (ACFs) using a plurality of instances in a plurality of different transmission/reception points (TRPs) with multi-connectivity. The plurality of TRPs may concurrently provide control services to a WTRU. Centralized control functions may manage core network connectivity and/or a plurality of user plane instances for the WTRU and/or may facilitate coordination between the plurality of ACF instances for the WTRU in the plurality of different TRPs of the WTRU's configuration.

Abstract: A system and methods for beam failure recovery and management for multi-carrier communications with beamforming are disclosed herein. A wireless transmit/receive unit (WTRU) may monitor for and detect a beam failure of a beam associated with a secondary cell (Scell). The WTRU may select an Scell candidate beam. The WTRU may transmit using a selected uplink (UL) resource in a primary cell (SpCell) a medium access control (MAC) control element (CE) including an indication of Scell beam failure and identifying the selected candidate beam. The WTRU may receive an Scell beam failure indication response on the SpCell indicating an SCell index and a downlink (DL) quasi co-location (QCL) reference associated with the Scell. The WTRU may verify that the DL QCL reference matches with the candidate beam. The WTRU may perform random access on the SCell using the selected QCL reference and the selected candidate beam.

Abstract: A WTRU may be configured to perform logical channel prioritization. A WTRU may receive an indication (e.g., a mapping) that indicates an association between a first HARQ process ID and a first HARQ processing type and between a second HARQ process ID and a second HARQ processing type. The WTRU may receive an indication (e.g., a mapping) that indicates an association between a first logical channel and the first HARQ processing type and between a second logical channel and the second HARQ processing type. The WTRU may receive an a HARQ process ID indication. The WTRU may determine a HARQ processing type associated with the HARQ process ID. The WTRU may determine a logical channel available for a transmission. The logical channel available to be used may be determined based on the HARQ processing type associated with the HARQ process ID. The WTRU may send the transmission.

Abstract: Methods and apparatus are described. A method, implemented in a wireless transmit/receive unit (WTRU) includes monitoring a first control channel search space (SS) associated with a first normal beam set comprising a first beam set. The WTRU initiates extended monitoring and monitors, subsequent to a trigger based on a measurement by the WTRU, a control channel SS associated with an extended beam set comprising the first beam set and one or more additional beam sets. The WTRU determines a second beam set from the extended beam set. The determination is based on a received control channel beam switch command or based on a control channel SS in which a beam switch command is received. The WTRU monitors a second control channel SS associated with a second normal beam set comprising the determined second beam set.

Abstract: Methods, devices and systems are provided for performing a random access (RA) procedure. A wireless transmit/receive unit (WTRU) may be configured to receive RA resource sets, where each of the RA resource sets is associated with a node-B directional beam, select an RA resource set from among the RA resource sets, and initiate an RA procedure based on the selected RA resource set. The RA procedure may include selecting multiple preambles which include a preamble for each resource of a plurality of resources corresponding to the selected RA resource set. The WTRU may be configured to sequentially transmit the selected multiple preambles in sequential RA transmissions, and may be configured to receive, from a node-B, in response to the RA transmissions, at least one RA response (RAR), where each of the received at least one RAR corresponds to one of the transmitted multiple preambles.

Abstract: Systems, procedures, and instrumentalities are disclosed for distributed control in wireless systems, such as 5G flexible radio access technology (RAT) (5gFLEX). Example procedures are provided for WTRU and network operation associated with a distributed control plane architecture, connectionless data transfer and dedicated system information acquisition. Distributed control may be provided, for example, by replicating a plurality of access control functions (ACFs) using a plurality of instances in a plurality of different transmission/reception points (TRPs) with multi-connectivity. The plurality of TRPs may concurrently provide control services to a WTRU. Centralized control functions may manage core network connectivity and/or a plurality of user plane instances for the WTRU and/or may facilitate coordination between the plurality of ACF instances for the WTRU in the plurality of different TRPs of the WTRU's configuration.

Abstract: Methods and apparatus for initial cell search and selection using beamforming are described. An apparatus is configured with multiple receive beams and includes an antenna and a processor. The processor is operatively coupled to the antenna and sweeps a respective one of the multiple receive beams during each of multiple synchronization sub-frames, using a pre-defined sweep time and dwell period, to detect a synchronization signal. The processor also obtains symbol timing information and a synchronization signal index from the detected synchronization signal. The obtained synchronization signal index corresponds to a synchronization signal index of the set. The process decodes a first broadcast channel using the obtained symbol timing information, the obtained synchronization signal index and a predefined or blind-coded symbol distance between the detected synchronization signal and the first broadcast channel.

Abstract: Methods and apparatuses are described herein for monitoring radio links between wireless transmit/receive units (WTRUs) and determining of radio link failure, and may be used, among others, for New Radio (NR) vehicular communication (V2X); a mode whereby WTRUs can communicate with each other directly. A radio link between a WTRU and another WTRU may be monitored independently per ongoing unicast and/or multicast link, and radio link failure (RLF) may be determined as a function of the monitoring.

Abstract: A wireless transmit/receive unit (WTRU) is configured to receive an identifier of a beam. The WTRU is configured to measure a downlink quality associated with at least one beam. The WTRU is configured to determine whether the measured downlink quality is below a threshold value. The WTRU is configured to receive at least one control channel transmission using the beam of the identifier in response to a determination that the measured downlink quality is below the threshold value, wherein the beam used to receive the at least one control channel transmission is a same beam used to receive an associated data channel transmission.

Abstract: Methods and apparatuses for initial access are described herein. A method may comprise receiving a signal in associated time and frequency resources. The signal may have an associated subcarrier spacing and an associated beam, and the signal may include synchronization signals and bits of a master information block. The method may further comprise determining control channel characteristics based on the signal. The characteristics may include a beam of at least one control channel and a location of the at least one control channel. The method may further comprise receiving a transmission over the at least one control channel based on the determined control channel characteristics.

Abstract: One or more techniques for beamformed paging are disclosed. A transmission/reception point (TRP) may transmit a paging inquiry signal using beam sweeping in a paging inquiry (PI) block with a different time, frequency resource set and/or sequence configuration associated with the same paging occasion (PO), for example, to randomize and/or distribute WTRUs into different monitoring groups. A WTRU may transmit an uplink paging inquiry response indicating a downlink beam for a paging data transmission and/or a WTRU ID. A downlink control and/or a data channel transmission may be triggered by a paging inquiry response transmission. Paging downlink control information may be transmitted in a WTRU-specific control channel, which may contain CRC bits masked by a temporary paging identity, e.g., based on a WTRU ID that may be reported in a paging inquiry response transmission. A WTRU paging procedure may be based on a paging inquiry signal and/or response transmission.

Abstract: A wireless transmit/receive unit (WTRU) may communicate with a serving cell and monitor suitable non-serving cell(s) may be monitored. Uplink-based forward mobility may be performed. The WTRU may transmit control signaling that may indicate an ordered list of candidate target cell(s) using resources of the source cell. A resume procedure towards a non-serving cell may be initiated while in connected state with serving cell. Upon a successful resume in non-serving cell, the connection may be disconnected from the serving cell.

Abstract: A wireless transmit/receive unit (WTRU) may communicate in a non-terrestrial network (NTN) comprising a plurality of satellites. The WTRU may be preconfigured with a plurality of measurement configurations and a corresponding plurality of activation/deactivation criteria associated with the plurality of satellites. The activation/deactivation criteria includes at least activation timing information. The WTRU may activate and deactivate each of the plurality of measurement configurations over time in accordance with the activation/deactivation criteria. The WTRU may perform measurements on cell beams for satellites with active measurement configurations and report results based on the measurements to NTN.

Abstract: A wireless transmit/receive unit (WTRU) configured to perform wireless communications in higher frequency bands (e.g., above 6 GHz) using a fallback scheme is provided. The WTRU includes a receiver configured to receive, in a time transmission interval (TTI), at least one control signal and a first data signal using a first beam associated with a first beam identifier (ID) and a second data signal, subsequent to the first data signal, using a second beam associated with a second beam ID different from the first beam ID, such that one of the at least one control signal indicates the second beam ID; and a processor configured to switch a receive beam of the receiver from the first beam to the second beam based on the second beam ID to receive the second data signal.

Abstract: Methods and apparatuses are described herein for BWP and SUL operation in wireless systems, especially in systems using a shared spectrum. In one embodiment, a wireless transmit/receive unit (WTRU) may receive information related to an upcoming channel occupancy time (COT) and use the received information to determine at least one resource for the operation of the WTRU during the COT. In one embodiment, the WTRU operating in a wireless network may transmit data on a first uplink carrier. It may trigger a switch from the first uplink carrier to a second uplink carrier based on at least one condition of the network and transmit data on the second uplink carrier.

Abstract: Method, apparatus and systems are disclosed. In one representative embodiment, a method may be implemented by a wireless transmit/receive unit (WTRU) for communication via a network access point (NAP). The method may include the WTRU receiving from the NAP a set of preambles and corresponding propagation delay related thresholds and determining propagation delay related information associated with a distance between the WTRU and the NAP or a location in a coverage of the NAP. The method may further include selecting a subset of preambles from the set of preambles based on the determined propagation delay related information, randomly selecting a preamble from the selected subset of preambles, and sending the randomly selected preamble to the NAP.

Abstract: A method and apparatus for receiving a broadcast configuration indicating when a change in a RAN function termination occurs is provided, for example, by a timer value. The broadcast configuration may be received from a satellite, blimp or other moving transmitter. A dedicated configuration may also be received from the serving cell. The dedicated configuration may include a preamble, a transient configuration and an indication of a layer 2 behavior. If a WTRU detects a change in RAN function termination, the WTRU may suspend any uplink data transmissions, apply the transient configuration and transmit the preamble to a target cell. The WTRU may synchronize with the target cell and apply the layer 2 behavior.

Abstract: A wireless transmit/receive unit (WTRU) may identify a plurality of candidate satellite constellations. The WTRU may determine an elevation angle and/or an orbit associated with each of the plurality of candidate satellite constellations. The WTRU may select a satellite constellation from the plurality of candidate constellations for sell selection. The WTRU may identify a plurality of candidate beams associated with the selected satellite constellation. The WTRU may determine an RSRP/RSRQ for each of the plurality of candidate beams. The WTRU may determine a weighted ranking of the plurality of candidate beams. The WTRU may determine the weighted ranking using the determined RSRP/RSRQ, prevailing load intensities, elevation angle, dwelling duration, link switch probability, and/or a quality of service (QoS). The WTRU may select a beam from the plurality of candidate beams for cell selection. The WTRU may select the beam based on the weighted ranking.