WO2022052989A1

WO2022052989A1 - Method and user equipment in non-terrestrial network

Info

Publication number: WO2022052989A1
Application number: PCT/CN2021/117461
Authority: WO
Inventors: Hsinhsi TSAI; Chienchun CHENG; Hengli CHIN
Original assignee: FG Innovation Company Limited
Priority date: 2020-09-09
Filing date: 2021-09-09
Publication date: 2022-03-17

Abstract

A method and a user equipment are provided. The method includes: receiving a Hybrid Automatic Repeat Request (HARQ) configuration from a Base Station (BS), the HARQ configuration indicating a state of a HARQ process; performing a new transmission using the HARQ process based on an Uplink (UL) grant; and selecting a logical channel for the UL grant based on an indication received from the BS, the indication indicating whether data from the logical channel can be transmitted using the HARQ process based on the state of the HARQ process.

Description

METHOD AND USER EQUIPMENT IN NON-TERRESTRIAL NETWORK

CROSS-REFERENCE TO RELATED APPLICATION (S)

The present disclosure claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 63/077,450, filed on September 11, 2020, entitled “DETERMINATION OF RANDOM ACCESS TYPE” ( “the ’450 provisional” ) and U.S. Provisional Patent Application Serial No. 63/076,299, filed on September 9, 2020, entitled “HARQ PROCESS ID SELECTION” ( “the ’299 provisional” ) . The content of the ’450 provisional and the ’ 299 provisional are hereby incorporated fully by reference into the present disclosure for all purposes.

FIELD

The present disclosure is related to wireless communication, and more particularly, to a method and a user equipment (UE) in a non-terrestrial network (NTN) in next generation wireless communication networks.

BACKGROUND

Various efforts have been made to improve different aspects of wireless communication for cellular wireless communication systems, such as 5G New Radio (NR) , by improving data rate, latency, reliability, and mobility. The 5G NR system is designed to provide flexibility and configurability to optimize the network services and types, accommodating various use cases such as enhanced Mobile Broadband (eMBB) , massive Machine-Type Communication (mMTC) , and Ultra-Reliable and Low-Latency Communication (URLLC) . However, as the demand for radio access continues to increase, there exists a need for further improvements in the art.

SUMMARY

The present disclosure is related to a method and a user equipment in non-terrestrial network (NTN) in the next generation wireless communication networks.

In a first aspect of the present disclosure, a method performed by a user equipment (UE) is provided. The method includes: receiving a Hybrid Automatic Repeat Request (HARQ) configuration from a Base Station (BS) , the HARQ configuration indicating a state of a HARQ process; performing a new transmission using the HARQ process based on an Uplink (UL) grant; and selecting a logical channel for the UL grant based on an indication received from the BS, the indication indicating whether data from the logical channel can be transmitted using the HARQ process based on the state of the HARQ process.

In an implementation of the first aspect of the present disclosure, the method further includes: selecting the logical channel for the UL grant without considering the indication if the UE is not configured with the HARQ configuration.

In an implementation of the first aspect of the present disclosure, the method further includes: determining whether to disable HARQ retransmission for the HARQ process based on the state of the HARQ process.

In an implementation of the first aspect of the present disclosure, the method further includes: enabling the HARQ retransmission for the HARQ process in a case that the state of the HARQ process indicates a first value; and disabling the HARQ retransmission for the HARQ process in a case that the state of the HARQ process indicates a second value.

In an implementation of the first aspect of the present disclosure, the method further includes: determining whether to start a DRX timer for the HARQ process after a UL transmission based on the state of the HARQ process.

In an implementation of the first aspect of the present disclosure, the method further includes: starting the DRX timer for the HARQ process after the UL transmission in a case that the state of the HARQ process indicates a first value; and not starting the DRX timer for the HARQ process after the UL transmission in a case that the state of the HARQ process indicates a second value.

In an implementation of the first aspect of the present disclosure, the UL grant is one of a dynamic grant and a configured grant.

In an implementation of the first aspect of the present disclosure, the indication is one of a list, a flag, an offset, and a threshold.

In an implementation of the first aspect of the present disclosure, the indication is configured by a logical channel configuration.

In an implementation of the first aspect of the present disclosure, the HARQ configuration is configured by a Radio Resource Control (RRC) message.

In a second aspect of the present disclosure, a UE is provided. The UE includes one or more non-transitory computer-readable media having computer-executable instructions embodied thereon; and at least one processor coupled to the one or more non-transitory computer-readable media. The at least one processor is configured to execute the computer-executable instructions to: receive a Hybrid Automatic Repeat Request (HARQ) configuration from a Base Station (BS) , the HARQ configuration indicating a state of a HARQ process; perform a new transmission using the HARQ process based on an Uplink (UL) grant; and select a logical channel for the UL grant based on an indication received from the BS, the indication indicating whether data from the logical channel can be transmitted using the HARQ process based on the state of the HARQ process.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the disclosure are best understood from the following detailed disclosure when read with the accompanying drawings. Various features are not drawn to scale. Dimensions of various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a schematic diagram illustrating a non-terrestrial network (NTN) that provides access to a user equipment (UE) according to an example implementation of the present disclosure.

FIG. 2 is a schematic diagram illustrating that an NTN that provides access to a UE according to another example implementation of the present disclosure.

FIG. 3 is a schematic diagram illustrating an Air-to-Ground (ATG) network according to an example implementation of the present disclosure.

FIG. 4 is a schematic diagram illustrating Timing Advance (TA) in an NTN according to an example implementation of the present disclosure.

FIG. 5 is a schematic diagram illustrating that the reference point (RP) is located at the next generation Node B (gNB) according to an example implementation of the present disclosure.

FIG. 6 is a schematic diagram illustrating that the RP is located at the satellite according to an example implementation of the present disclosure.

FIG. 7 is a schematic diagram illustrating that the RP localization is not specified according to an example implementation of the present disclosure.

FIG. 8 is a schematic diagram illustrating the scheduling of UE transmission according to an example implementation of the present disclosure.

FIG. 9 is a schematic diagram illustrating the impact of elevation angles and the corresponding Reference Signal Received Power (RSRP) in a cell according to an example implementation of the present disclosure.

FIG. 10 is a flowchart illustrating a method performed by a UE for hybrid automatic repeat request (HARQ) process operation in an NTN according to an example implementation of the present disclosure.

FIG. 11 is a block diagram illustrating a node for wireless communication according to an example implementation of the present disclosure.

DESCRIPTION

The following contains specific information related to implementations of the present disclosure. The drawings and their accompanying detailed disclosure are merely directed to implementations. However, the present disclosure is not limited to these implementations. Other variations and implementations of the present disclosure will be obvious to those skilled in the art. Unless noted otherwise, like or corresponding elements among the drawings may be indicated by like or corresponding reference numerals. Moreover, the drawings and illustrations in the present disclosure are generally not to scale and are not intended to correspond to actual relative dimensions.

For the purposes of consistency and ease of understanding, like features may be identified (although, in some examples, not illustrated) by the same numerals in the drawings. However, the features in different implementations may be different in other respects and shall not be narrowly confined to what is illustrated in the drawings.

The phrases “in one implementation, ” or “in some implementations, ” may each refer to one or more of the same or different implementations. The term “coupled” is defined as connected whether directly or indirectly via intervening components and is not necessarily limited to physical connections. The term “comprising” means “including, but not necessarily limited to” and specifically indicates open-ended inclusion or membership in the so-disclosed combination, group, series or equivalent. The expression “at least one of A, B and C” or “at least one of the following: A, B and C” means “only A, or only B, or only C, or any combination of A, B and C. ”

For the purposes of explanation and non-limitation, specific details such as functional entities, techniques, protocols, and standards are set forth for providing an understanding of the disclosed technology. In other examples, detailed disclosure of well-known methods, technologies, systems, and architectures are omitted so as not to obscure the present disclosure with unnecessary details.

Persons skilled in the art will immediately recognize that any network function (s) or algorithm (s) disclosed may be implemented by hardware, software or a combination of software and hardware. Disclosed functions may correspond to modules which may be software, hardware, firmware, or any combination thereof. A software implementation may include computer executable instructions stored on a computer readable medium such as memory or other type of storage devices. One or more microprocessors or general-purpose computers with communication processing capability may be programmed with corresponding executable instructions and perform the disclosed network function (s) or algorithm (s) . The microprocessors or general-purpose computers may include Application Specific Integrated Circuitry (ASIC) , programmable logic arrays, and/or using one or more Digital Signal Processor (DSPs) . Although some of the disclosed implementations are oriented to software installed and executing on computer hardware, alternative implementations implemented as firmware or as hardware or as a combination of hardware and software are well within the scope of the present disclosure.

The computer-readable medium includes but is not limited to Random Access Memory (RAM) , Read Only Memory (ROM) , Erasable Programmable Read-Only Memory (EPROM) , Electrically Erasable Programmable Read-Only Memory (EEPROM) , flash memory, Compact Disc Read-Only Memory (CD-ROM) , magnetic cassettes, magnetic tape, magnetic disk storage, or any other equivalent medium capable of storing computer-readable instructions.

A radio communication network architecture such as a Long-Term Evolution (LTE) system, an LTE-Advanced (LTE-A) system, an LTE-Advanced Pro system, or a 5G NR Radio Access Network (RAN) typically includes at least one base station (BS) , at least one UE, and one or more optional network elements that provide connection within a network. The UE communicates with the network such as a Core Network (CN) , an Evolved Packet Core (EPC) network, an Evolved Universal Terrestrial RAN (E-UTRAN) , a 5G Core (5GC) , or an internet via a RAN established by one or more BSs.

A UE may include but is not limited to a mobile station, a mobile terminal or device, or a user communication radio terminal. The UE may be a portable radio equipment that includes but is not limited to a mobile phone, a tablet, a wearable device, a sensor, a vehicle, or a Personal Digital Assistant (PDA) with wireless communication capability. The UE is configured to receive and transmit signals over an air interface to one or more cells in a RAN.

A BS may be configured to provide communication services according to at least a Radio Access Technology (RAT) such as Worldwide Interoperability for Microwave Access (WiMAX) , Global System for Mobile communications (GSM) that is often referred to as 2G, GSM Enhanced Data rates for GSM Evolution (EDGE) RAN (GERAN) , General Packet Radio Service (GPRS) , Universal Mobile Telecommunication System (UMTS) that is often referred to as 3G based on basic wideband-code division multiple access (W-CDMA) , high-speed packet access (HSPA) , LTE, LTE-A, evolved LTE (eLTE) that is LTE connected to 5GC, NR (often referred to as 5G) , and/or LTE-APro. However, the scope of the present disclosure is not limited to these protocols.

The BS may include but is not limited to a node B (NB) in the UMTS, an evolved node B (eNB) in LTE or LTE-A, a radio network controller (RNC) in UMTS, a BS controller (BSC) in the GSM/GERAN, an ng-eNB in an Evolved Universal Terrestrial Radio Access (E-UTRA) BS in connection with 5GC, a next generation Node B (gNB) in the 5G-RAN, or any other apparatus capable of controlling radio communication and managing radio resources within a cell. The BS may serve one or more UEs via a radio interface.

The BS is operable to provide radio coverage to a specific geographical area using a plurality of cells forming the RAN. The BS supports the operations of the cells. Each cell is operable to provide services to at least one UE within its radio coverage. Each cell (often referred to as a serving cell) may provide services to serve one or more UEs within its radio coverage such that each cell schedules the DL and optionally UL resources to at least one UE within its radio coverage for DL and optionally UL packet transmissions. The BS can communicate with one or more UEs in the radio communication system via the plurality of cells. A cell may allocate sidelink (SL) resources for supporting Proximity Service (ProSe) or Vehicle to Everything (V2X) service. Each cell may have overlapped coverage areas with other cells.

As discussed above, the frame structure for NR supports flexible configurations for accommodating various next generation (e.g., 5G) communication requirements such as Enhanced Mobile Broadband (eMBB) , Massive Machine Type Communication (mMTC) , and Ultra-Reliable and Low-Latency Communication (URLLC) , while fulfilling high reliability, high data rate and low latency requirements. The Orthogonal Frequency-Division Multiplexing (OFDM) technology in the 3rd Generation Partnership Project (3GPP) may serve as a baseline for an NR waveform. The scalable OFDM numerology such as adaptive sub-carrier spacing, channel bandwidth, and Cyclic Prefix (CP) may also be used. Additionally, two coding schemes are considered for NR, specifically Low-Density Parity-Check (LDPC) code and Polar Code. The coding scheme adaption may be configured based on channel conditions and/or service applications.

Moreover, it is also considered that in a transmission time interval TX of a single NR frame, downlink (DL) transmission data, a guard period, and uplink (UL) transmission data should at least be included, where the respective portions of the DL transmission data, the guard period, and the UL transmission data should also be configurable, for example, based on the network dynamics of NR. In addition, sidelink resources may also be provided in an NR frame to support ProSe services.

In addition, the terms “system” and “network” herein may be used interchangeably. The term “and/or” herein is only an association relationship for describing associated objects and represents that these relationships may exist. For example, A and/or B may indicate that: A exists alone, A and B exist at the same time, or B exists alone. In addition, the character “/” herein generally represents that the former and latter associated objects are in an “or” relationship.

Examples of some selected terms are provided as follows.

Random Access (RA) Procedure: The random access procedure may be triggered by the following events:

- Initial access from RRC_IDLE

- RRC Connection Re-establishment procedure

- DL or UL data arrival during RRC_CONNECTED when UL synchronization status is "non-synchronized"

- UL data arrival during RRC_CONNECTED when there are no PUCCH resources for SR available

- SR failure

- Request by RRC upon synchronous reconfiguration (e.g., handover)

- Transition from RRC_INACTIVE

- To establish time alignment for a secondary TAG

- Request for Other SI

- Beam failure recovery

- Consistent UL LBT failure on SpCell

Two types of random access procedure may be supported: 4-step RA type with Msg1 and 2-step RA type with MsgA. Both types of RA procedure support contention-based random access (CBRA) and contention-free random access (CFRA) . The UE may select the type of random access at initiation of the random access procedure based on network configuration:

- when CFRA resources are not configured, an RSRP threshold is used by the UE to select between 2-step RA type and 4-step RA type.

- when CFRA resources for 4-step RA type are configured, UE performs random access with 4-step RA type.

- when CFRA resources for 2-step RA type are configured, UE performs random access with 2-step RA type.

The network may not configure CFRA resources for 4-step and 2-step RA types at the same time for a Bandwidth Part (BWP) . CFRA with 2-step RA type may be only supported for handover. The Msg1 of the 4-step RA type may consist of a preamble on PRACH. After Msg1 transmission, the UE may monitor for a response from the network within a configured window. For CFRA, dedicated preamble for Msg1 transmission may be assigned by the network and upon receiving random access response from the network, the UE may end the random access procedure. For CBRA, upon reception of the random access response, the UE may send Msg3 using the UL grant scheduled in the response and may monitor contention resolution. If contention resolution is not successful after Msg3 (re) transmission (s) , the UE may go back to MSG1 transmission.

The MsgA of the 2-step RA type includes a preamble on PRACH and a payload on PUSCH. After MsgA transmission, the UE may monitor for a response from the network within a configured window. For CFRA, dedicated preamble and PUSCH resource are configured for MsgA transmission and upon receiving the network response, the UE may end the random access procedure. For CBRA, if contention resolution is successful upon receiving the network response, the UE may end the random access procedure; while if fallback indication is received in MsgB, the UE may perform Msg3 transmission using the UL grant scheduled in the fallback indication and may monitor contention resolution. If contention resolution is not successful after Msg3 (re) transmission (s) , the UE may go back to MsgA transmission.

If the random access procedure with 2-step RA type is not completed after a number of MsgA transmissions, the UE may be configured to switch to CBRA with 4-step RA type. For random access in a cell configured with SUL, the network may explicitly signal which carrier to use (UL or SUL) . Otherwise, the UE may select the SUL carrier if and only if the measured quality of the DL is less than a broadcast threshold. UE may perform carrier selection before selecting between 2-step and 4-step RA type. The RSRP threshold for selecting between 2-step and 4-step RA type may be configured separately for UL and SUL. Once started, all uplink transmissions of the random access procedure may remain on the selected carrier.

When CA is configured, random access procedure with 2-step RA type may be only performed on PCell while contention resolution may be cross-scheduled by the PCell. When CA is configured, for random access procedure with 4-step RA type, the first three steps of CBRA may always occur on the PCell while contention resolution (step 4) may be cross-scheduled by the PCell. The three steps of a CFRA started on the PCell remain on the PCell. CFRA on SCell may only be initiated by the gNB to establish timing advance for a secondary TAG: the procedure may initiated by the gNB with a PDCCH order (step 0) that is sent on a scheduling cell of an activated SCell of the secondary TAG, preamble transmission (step 1) may take place on the indicated SCell, and Random Access Response (step 2) may take place on PCell.

Uplink Scheduling: In the uplink, the gNB may dynamically allocate resources to UEs via the Cell-Radio Network Temporary Identifier (C-RNTI) on PDCCH (s) . A UE may monitor the PDCCH (s) in order to find possible grants for uplink transmission when its downlink reception is enabled (activity governed by DRX when configured) . When Carrier Aggregation (CA) is configured, the same C-RNTI may apply to all serving cells. The UE may be configured with up to 12 active configured uplink grants for a given Bandwidth Part (BWP) of a serving cell. When more than one is configured, the network may decide which of these configured uplink grants are active at a time (including all of them) . Each configured uplink grant may either be of Type 1 or Type 2. For Type 2, activation and deactivation of configured uplink grants may be independent among the serving cells. When more than one Type 2 configured grant is configured, each configured grant may be activated separately using a Downlink Control Information (DCI) command and deactivation of Type 2 configured grants may be done using a DCI command, which can either deactivate a single configured grant configuration or multiple configured grant configurations jointly.

Non-Terrestrial Network (NTN) : An NTN may refer to a network, or segment of networks using Radio Frequency (RF) resources on board a satellite (or Unmanned Aircraft System (UAS) platform) . A Non-Terrestrial Network typically may feature the following elements.

One or several satellite gateways (sat-gateways) that connect the NTN to a public data network. A Geostationary Earth Orbit (GEO) satellite may be fed by one or several sat-gateways which are deployed across the satellite targeted coverage (e.g., regional or even continental coverage) . A UE in a cell may be served by only one sat-gateway. A Non-GEO satellite may be served successively by one or several sat-gateways at a time. The system may ensure service and feeder link continuity between the successive serving sat-gateways with sufficient time duration to proceed with mobility anchoring and handover. A feeder link or radio link may be provided between a sat-gateway and the satellite (or UAS platform) . A service link or radio link may be provided between the user equipment and the satellite (or UAS platform) . A satellite (or UAS platform) which may implement either a transparent or a regenerative (with onboard processing) payload. The satellite (or UAS platform) may generate several beams over a given service area bounded by its field of view. The footprints of the beams may be typically of elliptic shape. The field of view of a satellite (or UAS platform) may depend on the onboard antenna diagram and minimum elevation angle.

Transparent payload: Radio Frequency filtering, Frequency conversion and amplification. The waveform signal repeated by the payload may be unchanged.

Regenerative payload: Radio Frequency filtering, Frequency conversion and amplification as well as demodulation/decoding, switching and/or routing, coding/modulation. This may be effectively equivalent to having all or part of the functions of a base station (e.g., gNB) onboard the satellite (or UAS platform) .

Inter-satellite links (ISL) optionally in case of a constellation of satellites. This may require regenerative payloads onboard the satellites. ISL may operate in RF frequency or optical bands. The UE may be served by the satellite (or UAS platform) within the targeted service area.

User Equipment (UE) : The UE may be referred to as a Physical (PHY) /Medium Access Control (MAC) /Radio Link Control (RLC) /Packet Data Convergence Protocol (PDCP) /Service Data Adaptation Protocol (SDAP) entity. The PHY/MAC/RLC/PDCP/SDAP entity may be referred to as the UE.

Network (NW) : The NW may be a network node, a Transmission Reception Point (TRP) , a cell (e.g., Special Cell (SpCell) , Primary Cell (PCell) , Primary Secondary Cell (PSCell) , and/or Secondary Cell (SCell) ) , an eNB, a gNB, a core network, and/or a base station.

Serving Cell: A SpCell, a PCell, a PSCell, or an SCell. The serving cell may be an activated or a deactivated serving cell.

Special Cell (SpCell) : For Dual Connectivity (DC) operation, the SpCell may refer to the PCell of the Master Cell Group (MCG) or the PSCell of the Secondary Cell Group (SCG) depending on if the MAC entity is associated to the MCG or the SCG, respectively. Otherwise, the SpCell may refer to the PCell. A SpCell may support Physical Uplink Control Channel (PUCCH) transmission and contention-based Random Access (RA) and may be always activated.

Configured Grant (CG) : The gNB may allocate/configure uplink resources for the initial HARQ transmissions and/or the HARQ retransmissions to UEs. Two types of configured uplink grants may be provided. With CG type 1, RRC/gNB may directly provide the configured uplink grant (e.g., including the periodicity) . With CG type 2, RRC/gNB may define the periodicity of the configured uplink grant while the Physical Downlink Control Channel (PDCCH) addressed to Configured Scheduling-Radio Network Temporary Identifier (CS-RNTI) can either activate the configured uplink grant, and/or deactivate it (e.g., a PDCCH addressed to CS-RNTI may indicate that the uplink grant is implicitly used according to the periodicity defined by RRC/gNB, until deactivated) .

Dynamic Grant (DG) : The gNB can dynamically allocate UL resources to UEs via the C-RNTI on PDCCH.

Random Access Response (RAR) grant: A UL grant may be provided via Message 2 (Msg2) /RAR and/or Message B (MsgB) during the 4-step/2-step Random Access (RA) procedure. The UL grant may be included in MAC payload for RAR and/or MsgB (e.g., MAC RAR and/or fallback RAR) . The UL grant may be provided by an Uplink Grant field that indicates the resources to be used on the UL channel (e.g., PUSCH) . The size of the UL Grant field may be but is not limited to 27 bits. The UL transmission based on the RAR grant may be transmitted via Message 3 (Msg3) .

Message A (MsgA) : MsgA may include a Physical Random Access Channel (PRACH) preamble and a Physical Uplink Shared Channel (PUSCH) transmission, known as MsgA PRACH and MsgA PUSCH, respectively. MsgA may be transmitted during a 2-step RA procedure.

MsgA PRACH: The MsgA PRACH preambles may be separated from the 4-step Random Access Channel (RACH) preambles but may be transmitted in the same PRACH Occasions (ROs) as the preambles of 4-step RACH, or in separate ROs.

MsgA PUSCH: The PUSCH transmissions may be organized into PUSCH Occasions (POs) which may span multiple symbols and Physical Resource Blocks (PRBs) with optional guard periods and guard bands between consecutive POs. Each PO may include multiple Demodulation Reference Signal (DMRS) ports and/or DMRS sequences, with each DMRS port/DMRS sequence pair known as PUSCH resource unit (PRU) . 2-step RA procedure may support at least one-to-one and multiple-to-one mapping between the preambles and PRUs.

FIG. 1 is a schematic diagram illustrating a non-terrestrial network (NTN) that provides access to a user equipment (UE) 107 according to an example implementation of the present disclosure. As illustrated in FIG. 1, a satellite (or UAS platform) 101 may be connected to a data network 103 based on a sat-gateway 105. A feeder link (or radio link) 102 may be provided between the sat-gateway 105 and the satellite (or UAS platform) 101. A service link (or radio link) 104 may be provided between a UE 107 and the satellite (or UAS platform) 101. The satellite (or UAS platform) 101 may implement a transparent payload. The satellite (or UAS platform) may generate several beams over a given service area bounded by its field of view 106. The footprints of the beams 108 may be typically of elliptic shape. The field of view 106 of the satellite (or UAS platform) 101 may depend on the onboard antenna diagram and minimum elevation angle. The UE 107 may be served by the satellite (or UAS platform) 101 within the targeted service area.

FIG. 2 is a schematic diagram illustrating an NTN that provides access to a UE 207 according to another example implementation of the present disclosure. As illustrated in FIG. 2, a first satellite (or UAS platform) 201 and a second satellite (or UAS platform) 209 may be connected to a data network 203 based on a sat-gateway 205. A first feeder link (or radio link) 202 may be provided between the sat-gateway 205 and the first satellite (or UAS platform) 201. A second feeder link (or radio link) 210 may be provided between the sat-gateway 205 and the second satellite (or UAS platform) 209. A service link (or radio link) 204 may be provided between a UE 207 and the first satellite (or UAS platform) 201. Each of the first satellite (or UAS platform) 201 and the second satellite (or UAS platform) 209 may implement a regenerative payload. The satellite (or UAS platform) may generate several beams over a given service area bounded by its field of view 206. The footprints of the beams 208 may be typically of elliptic shape. The field of view 206 of the first satellite (or UAS platform) 201 may depend on the onboard antenna diagram and minimum elevation angle. The UE 207 may be served by the satellite (or UAS platform) 201 within the targeted service area. ISL 211 may be provided between the first satellite (or UAS platform) 201 and the second satellite (or UAS platform) 209. If the ISL 211 is provided, it may be required the regenerative payloads onboard the first satellite (or UAS platform) 201 and the second satellite (or UAS platform) 209. ISL 211 may operate in RF frequency or optical bands. If the ISL 211 is not provided, the first feeder link (or radio link) 202 may be mandatory.

Table 1 below includes an example of different types of satellites (or UAS platforms) .

Table 1

An Air-to-Ground (ATG) network may be included in the NTN framework that refers to in-flight connectivity techniques, using ground-based cell towers that send signals up to an aircraft’s antenna (s) of an onboard ATG terminal. As a plane (or aircraft) travels into different sections of airspace, the onboard ATG terminal may automatically connect to the cell with the strongest received signal power, just as a mobile phone does on the ground. An ATG gNB may be deployed on the ground, with antennas pointing upward to form an aerial cell, while an aircraft performs as a special UE. An ATG air interface may refer to the connection between the ATG gNB and the aircraft, while the connections between the aircraft and the passenger’s devices may be based on Wi-Fi technology.

Like the satellites described in FIG. 1 and FIG. 2, the ATG may handle an extremely large cell coverage range (e.g., up to 300 km) and high speed (e.g., up to 1200km/h) . FIG. 3 is a schematic diagram illustrating an ATG network according to an example implementation of the present disclosure. Each ATG gNB 301 to 304 deployed on the ground 305 may be provided with antennas pointing upward to form aerial cells 306 to 309, and an aircraft 310 may perform as a special UE. An ATG air interface may connect ATG gNBs 301 to 304 and the aircraft 310, while Wi-Fi may connect the aircraft 310 and the passenger’s devices.

With consideration on the larger cell coverage, long round trip time (RTT) and high Doppler, enhancements may be considered to ensure the performance for timing and frequency synchronization for uplink (UL) transmission. The Timing Advance (TA) (or referred to full TA) applied by an UE in RRC_IDLE, RRC_INACTIVE, and/or RRC_CONNECTED state may be given by following equation:

TA = N_TA + UE-specific TA + Common TA + TA_offset

Where N_TA may be defined as 0 (zero) for Physical Random Access Channel (PRACH) and updated based on TA command field in Message 2 (Msg2) /Message B (MsgB) and/or TA command Medium Access control (MAC) Control Element (CE) . UE-specific TA may be a UE self-estimated TA to pre-compensate for the service link delay. UE-specific TA may be autonomously acquired at UE with UE known location and satellite ephemeris. Common TA may be a NW-controlled common TA and may include any timing offset considered necessary by the NW. Common TA with value 0 may be supported. Common TA may be broadcasted by the NW to the UE. TA_offset may be a fixed offset used to calculate the timing advance.

FIG. 4 is a schematic diagram illustrating TA in an NTN according to an example implementation of the present disclosure. In some implementations, NW may broadcast the real-time position of a satellite 401 (e.g., satellite ephemeris) via a System Information Block (SIB) to the UE 402. The UE 402 may derive the current satellite position based on its last acquisition of the satellite ephemeris and some basic propagator model. Then the UE 402 may acquire the propagation delay between the satellite 401 and the UE 402. That is, the UE-specific TA 403 may be acquired by UE 402’s Global Navigation Satellite System (GNSS) receiver and satellite’s position provided by NW. On the other hand, the common TA 404 may be defined as the common component of propagation delay shared by all UEs within the cell coverage and corresponds to the Real Time Difference (RTD) between the reference point (RP) 405 and the satellite 401. (Note that the common TA 404 may be zero if the RP 405 is located at the satellite 401, or equal to NTN Gateway (GW) 406 to satellite RTD if RP 405 is located at the NTN GW 406 depending on the implementation) . The RTD experienced between the gNB 407 and the RP 405 may be compensated by the network, which may be transparent to the UE 402.

The required TA value for UL transmission including PRACH may be calculated by the UE. The corresponding adjustment may be done, either with UE-specific TA or full TA (consisting of UE-specific TA and common TA) . With respect to the full TA compensation at the UE side, both the alignment on the UL timing among UEs and downlink (DL) and UL frame timing at network side may be achieved. With respect to UE-specific TA only, additional indication on a single reference point may be signalled to UEs per beam/cell for achieving the UL timing alignment among UEs within the coverage of the same beam/cell. Timing offset between DL and UL frame timing at the network side may also be managed by the network regardless of the satellite payload type.

The common TA, which refers to the common component of propagation delay shared by all UEs within the coverage of same satellite beam/cell, may be broadcasted by the network (per satellite beam/cell) . The calculation of this common TA may be conducted by the network with the assumption on at least a single reference point per satellite beam/cell. For satisfying the larger coverage of NTN, the extension of the value range for TA indication in RAR, either explicitly or implicitly, may be identified. A negative TA value in the corresponding indication may be supported. Moreover, the indication of the timing drift rate, from the network to UE, may also be supported to enable the TA adjustment at the UE side. For calculation of common TA, a single reference point per beam may be considered as the baseline.

In NTN, it may assume that a transparent or “bent-pipe” configuration will be deployed, where the gNB may be located on the ground and a satellite relays signalling between the gNB and the UE. This configuration may be comprised of two portions of propagation delay that are associated with the connection between the gNB and satellite, defined as the “feeder link” and that between the UE and satellite, e.g., service link. The feeder link delay component may be common to all UEs served by the cell, whereas the delay between the UE and satellite (e.g., service-link) may be further broken down into the following two components:

- Common delay: The common delay may represent the minimum delay from the satellite to the ground (i.e., the propagation delay between the satellite and a reference point such as the cell centre) .

- UE specific delay: The UE specific delay may be based on the UE-specific distance to the reference point.

When the TA is autonomously acquired by UE. The reference point may be defined differently. This makes impacts on how to define the common delay and the UE-specific delay. In NTN, it is proposed to consider the reference point for UL timing synchronization at the satellite. It means that Timing Advance acquisition and updates may be computed considering the satellite position as the reference for UL timing synchronization. As a result, the UL and DL frames may be aligned only at the satellite. The gNB may be able to deal with a time shift of two times the gNB-Satellite common propagation delay between UL and DL frames. This gNB-Satellite common delay may be going to change continuously with time due to satellite mobility. Note that this common delay may be broadcasted within the NTN SIB if needed. Some other variations on the time reference or reference point (RP) may be also provided to achieve similar benefits.

FIG. 5 is a schematic diagram illustrating that the RP 501 is located at the gNB 504 according to an example implementation of the present disclosure. As illustrated in FIG. 5, the RP 501 may be located at the gNB 504. The initial TA acquisition (before PRACH transmission) may be computed as the sum of the two distinct contributions:

- The UE specific TA which is autonomously acquired by the UE 503 based on its GNSS capabilities and additional network indications (e.g., satellite ephemeris or timestamp) . It may correspond to the service link RTD T_51. The UE specific TA may be given by the following equation:

UE specific TA = 2xT_51

- The Common TA which is indicated by the network. It may correspond to the RTD T_50 experienced between the RP 501 and the satellite 502. The Common TA may be given by the following equation:

Common TA = 2xT_50

The initial TA may be given by the following equation:

TA = UE specific TA + Common TA = 2xT_51 + 2xT_50

FIG. 6 is a schematic diagram illustrating that the RP 601 is located at the satellite 602 according to an example implementation of the present disclosure. As illustrated in FIG. 6, the RP 601 may be located at the satellite 602. The initial TA acquisition (before PRACH transmission) may be computed as the sum of two distinct contributions:

- The UE specific TA which is autonomously acquired by the UE 603 based on its GNSS capabilities and additional network indications (e.g., satellite ephemeris or timestamp) . It may correspond to the service link RTD T_61. The UE specific TA may be given by the following equation:

UE specific TA = 2xT_61

- The Common TA which corresponds to the RTD experienced between the RP 601 and the satellite 602 may be equal to zero. The common TA indication may not be needed. The Common TA may be given by the following equation:

Common TA = 0

The initial TA may be given by the following equation:

TA = UE specific TA + Common TA = 2xT_61 + 0

FIG. 7 is a schematic diagram illustrating that the RP 701 localization is not specified according to an example implementation of the present disclosure. As illustrated in FIG. 7, the RP 701 localization may not be specified and left to the implementation. The initial TA acquisition (before PRACH transmission) may be computed as the sum of two distinct contributions:

The UE specific TA which is autonomously acquired by the UE 703 based on its GNSS capabilities and additional network indications (e.g., satellite ephemeris or timestamp) . It may correspond to the service link RTD T_71. The UE specific TA may be given by the following equation:

UE specific TA = 2xT_71

The Common TA which is indicated by the network. It may correspond to the RTD T_70 experienced between the RP 701 and the satellite 702. The common TA may be either positive or negative. Therefore, the RP 701 may be located either on the feeder link or the service link. The Common TA may be given by the following equation:

Common TA = 2xT_70

The initial TA may be given by the following equation:

TA = UE specific TA + Common TA = 2xT_71 + 2xT_70

Common TA and UE-specific TA may have different definitions based on following cases:

Case 1: For NW-based TA (NW broadcasts cell-specific reference TA) . Common TA may be the minimum RTT from the satellite to a reference point in a serving cell. UE-specific TA may be the minimum RTT from a UE to a reference point in a serving cell.

Case 2: For UE-autonomous TA (UE estimations TA based on GNSS and ephemeris) . Common TA may be the minimum RTT from a satellite to a reference point on gNB, satellite, feeder link and/or service link. UE-specific TA may be the minimum RTT from a UE to a satellite.

The (MAC sublayer of) UE may support error correction and/or repetition through Hybrid Automatic Repeat Request (HARQ) . The HARQ functionality may ensure delivery between peer entities at Layer 1 (e.g., physical layer) .

For the NTN, the network may disable HARQ feedback for downlink (DL) transmission at the UE receiver, e.g., to cope with long propagation delays. Even if the HARQ feedback is disabled, the HARQ processes may be still configured. Enabling/disabling of the HARQ feedback may be a network decision signaled semi-statically to the UE by Radio Resource Control (RRC) signaling. The enabling/disabling of the HARQ feedback for downlink transmission may be configurable on a per UE and/or per HARQ process basis via RRC signaling.

For the NTN, the network may disable HARQ retransmission for uplink transmission at the UE transmitter. Even if the HARQ retransmissions are disabled, the HARQ processes may be still configured. The enabling/disabling of the HARQ retransmission for uplink (UL) transmission may be configured per UE, per HARQ process and/or per logical channel (LCH) basis.

Multiple transmissions of the same Transport Block (TB) in a bundle (e.g., MAC schedules packets in a bundle with pdsch-AggregationFactor > 1 in downlink and/or pusch-AggregationFactor > 1 in the uplink) may be possible and may be useful to lower the residual Block Error Rate (BLER) , particularly in case HARQ feedback and/or HARQ retransmission is disabled. Soft combining of multiple transmissions may be supported in the receiver of the UE. Multiple transmissions of the same TB (e.g., MAC schedules the same TB on the same HARQ process without the New Data Indicator (NDI) being toggled) are possible and may also be useful to lower the residual BLER, particularly in case the HARQ feedback and/or HARQ retransmission is disabled.

If the HARQ feedback and/or the HARQ retransmission is disabled for a selective number (e.g., not all) of HARQ processes, the configured parameters/Information Elements (IEs) for different HARQ processes may be different.

In the NTN, the HARQ process (es) for DL transmission and/or the HARQ process (es) for UL transmission may be disabled/enabled, by NW configuration and/or UE itself. In some implementations, the HARQ process (es) for DL and/or the HARQ process (es) for UL may be disabled/enabled per UE. In some implementations, the HARQ process (es) for DL and/or the HARQ process (es) for UL may be disabled/enabled per HARQ process.

For per UE basis, in a DL aspect, all the (configured) HARQ processes (of the UE) for DL transmission may be disabled/enabled at the same time, e.g., when receiving the NW configuration for disabling/enabling the HARQ process (es) . In a UL aspect, all the (configured) HARQ processes (of the UE) for UL transmission may be disabled/enabled at the same time, e.g., when receiving the NW configuration for disabling/enabling the HARQ process (es) .

For per HARQ process basis, in a DL aspect, one or multiple of the HARQ process (es) for DL transmission may be disabled/enabled, e.g., based on configuration. For example, assuming that a UE has 16 HARQ processes for DL transmission, HARQ processes 0 to 3 for DL transmission may be enabled, while HARQ processes 4 to 15 for DL transmission may be disabled. In a UL aspect, one or multiple HARQ process (es) for UL transmission may be disabled/enabled, e.g., based on configuration. For example, assuming that a UE has 16 HARQ processes for UL transmission, HARQ processes 0 to 3 for UL transmission may be enabled, while HARQ processes 4 to 15 for UL transmission may be disabled.

I. Trigger/Determination of 2-step/4-step RA type

FIG. 8 is a schematic diagram illustrating the scheduling of UE transmission according to an example implementation of the present disclosure. The typical procedure when data arrives in the buffer 801 is to trigger a Buffer Status Report (BSR) and if the UE 802 does not have any uplink resources for transmitting the BSR, the UE may go on to do a Scheduling Request (SR) 803 to ask for resources. Since the scheduling request 803 is only an indication telling the network (e.g., gNB) 804 that the UE 802 requires scheduling, the network 804 may not know the full extent of the resources required to schedule the UE 802, thus the network 804 may typically schedule the UE 802 with a grant large enough to send a BSR 805 so that the network 804 may schedule the UE 802, as illustrated in FIG. 8.

In non-terrestrial networks, the drawback of this procedure is that it would take at least 2 Round-trip times from data arriving in the buffer at the UE side until it can be properly scheduled with resources that would fit the data and the required Quality of Service (QoS) . Due to the large propagation delays, this may become prohibitively large. Table 2 below includes an example of scheduling enhancement options. For this issue, there are some options as shown in Table 2.

Table 2

For option 5, the BSR over 2-step RA may imply that the BSR MAC CE should be transmitted via MsgA PUSCH. However, a RA procedure may only be triggered by the following events:

- Initial access from RRC_IDLE

- RRC Connection Re-establishment procedure

- SR failure

- Request by RRC upon synchronous reconfiguration (e.g., handover)

- Transition from RRC_INACTIVE

- To establish time alignment for a secondary Timing Advance Group (TAG)

- Request for Other SI

- Beam failure recovery

- Consistent UL Listen Before Talk (LBT) failure on SpCell

That is, when a BSR is triggered, and/or a BSR MAC CE is generated, it may not be guaranteed that the BSR MAC CE would be transmitted via 2-step RACH (e.g., MsgA PUSCH) since the UE may not trigger any RA procedure at that time. Furthermore, even if the UE triggers a RA procedure, the UE may not select the 2-step RA type for the RA procedure, i.e., the UE may perform 4-step RA procedure. The UE may only select/set the 2-step RA type based on Reference Signal Received Power (RSRP) of the DL pathloss reference, e.g., if RSRP of the DL pathloss reference is above msgA-RSRP-Threshold (in a case that the Bandwidth Part (BWP) selected for Random Access procedure is configured with both 2-step and 4-step RA type Random Access Resources) . Consequently, some methods may be introduced to support the BSR over 2-step RA in NTN.

On the other hand, except for BSR MAC CE, some MAC CEs (e.g., Beam Failure Recovery (BFR) MAC CE and/or LBT failure MAC CE) may also be delay-sensitive, which means the UE may need to transmit these MAC CEs to NW as soon as possible. For these MAC CEs, if there is no available UL resource for transmitting the MAC CE, the UE may trigger a specific SR based on the current mechanism. However, due to long propagation delay in NTN, may be beneficial to transmit these MAC CEs via 2-step RA. In this sense, some methods may be introduced to support some MAC CE(s) transmitted over 2-step RA.

In some implementations, a new criterion (s) for triggering/initiating a RA procedure and/or a new criterion (s) to set 2-step RA type for the RA procedure may be provided. The criteria may be one or more of the following. The combination of multiple criteria may be possible.

When a BSR is triggered and/or when a BSR MAC CE is generated, the UE may trigger (e.g., initiate) a RA procedure (for the BSR) and/or set 2-step RA type for the RA procedure. When a BSR is triggered and/or when a BSR MAC CE is generated, the UE may or may not trigger an SR (e.g., even if the UE has valid PUCCH resources for the SR) , the UE may directly trigger a RA procedure (for the BSR) and/or set 2-step RA type for the RA procedure. The BSR may be triggered for a specific LCH (e.g., an LCH configured with an indication, restriction, and/or a mask) . The indication used to indicate that when the BSR is triggered by the specific LCH, the UE may (directly) trigger the RA procedure. (e.g., skip triggering and/or transmitting SR) and/or set 2-step RA type for the RA procedure. The BSR may be a specific BSR (e.g., a regular BSR, a periodic BSR, a long BSR, a short BSR, and/or a padding BSR) . The BSR may be triggered by a specific BSR configuration. The specific BSR configuration may co-exist with the current BSR configuration. The specific BSR configuration may be configured in NTN.

When a UE-specific TA (and/or a specific UE information) is triggered and/or a UE-specific TA (and/or a specific UE information) MAC CE is generated, the UE may trigger a RA procedure (for the UE-specific TA (and/or the specific UE information) ) and/or set 2-step RA type for the RA procedure. When a UE-specific TA (and/or a specific UE information) is triggered and/or when a UE-specific TA (and/or a specific UE information) MAC CE is generated, the UE may or may not trigger a SR (e.g., even if the UE has valid PUCCH resources for SR) , the UE may directly trigger a RA procedure (for the UE-specific TA (and/or a specific UE information) ) and/or set 2-step RA type for the RA procedure. The UE-specific TA (and/or a specific UE information) may include one or more of the following information:

- UE-specific TA value/offset calculated by the UE (e.g., based on GNSS, satellite-specific characteristics such as location, the direction of movement, and speed via ephemeris data, etc. )

- TA (including UE specific TA and common TA)

- Propagation delay between UE and satellite (e.g., RTT between UE and satellite)

- Full propagation delay (e.g., RTT between UE and gNB)

- Common delay, representing the minimum delay from the satellite to the ground (i.e., the propagation delay between the satellite and a reference point such as the cell centre)

- UE specific delay, based on the UE-specific distance to the reference point

- Common delay compensation, where the delay includes the feeder link delay + delay from the satellite to a reference point (for example, the center of a beam/cell) . This delay is broadcasted by the network, and the UE may use this value for timing pre-compensation.

- UE-specific delay compensation, where the delay includes the feeder-link delay + UE specific delay calculated by the UE via e.g., distance from the UE to the satellite. The feeder link delay will be broadcasted, and the UE may add the calculated UE-specific value to obtain the full RTD for timing pre-compensation

- UE-specific frequency offset

- Full frequency offset

When a BFR is triggered and/or a BFR MAC CE is generated, the UE may trigger a RA procedure (for BFR) and/or set 2-step RA type for the RA procedure. When a BFR is triggered and/or when a BSR MAC CE is generated, the UE may or may not trigger an SR (for the BFR) (e.g., even if the UE has valid PUCCH resources for SR) , the UE may directly trigger a RA procedure (for the BFR) and/or set 2-step RA type for the RA procedure. The BFR may be a BFR for SpCell and/or a BFR for SCell. The BFR MAC CE may be BFR MAC CE and/or truncated BFR MAC CE.

When a consistent LBT failure is triggered and/or when a BSR MAC CE is generated, the UE may trigger a RA procedure (for consistent LBT failure) and/or set 2-step RA type for the RA procedure. When a consistent LBT failure is triggered and/or when an LBT failure MAC CE is generated, the UE may or may not trigger an SR (for consistent LBT failure) (e.g., even if the UE has valid PUCCH resources for SR) , the UE may directly trigger a RA procedure (for consistent LBT failure) and/or set 2-step RA type for the RA procedure. The RA procedure may (only) be triggered/initiated when the UE is operating in NTN (e.g., LEO and/or GEO) . An NTN UE or a UE operating in NTN may report a specific UE capability.

When a BSR is triggered and/or when a BSR MAC CE is generated, an NTN UE may trigger/initiate a RA procedure (for the BSR) and/or set 2-step RA type for the RA procedure if the NTN UE has been configured with a specific dedicated/common RRC IE by the network. A UE may be regarded as an NTN UE if the UE has reported a specific UE capability.

The RA procedure may be triggered/initiated by a UE with a specific access identity and/or access category. The RA procedure may be initiated on a Spell and/or an SCell. The RA procedure may be a 2-step RA type and/or a 4-step RA type. The UE may set the RA_TYPE to 2-stepRA for the RA procedure. The UE may not set the RA TYPE to 4-step RA for the RA procedure. The RA procedure may be a contention-free and/or contention-based RA procedure. The RA procedure may be initiated/triggered by one or more of the following events:

- Initial access from RRC_IDLE

- RRC Connection Re-establishment procedure

- SR failure

- Request by RRC upon synchronous reconfiguration (e.g., handover)

- Transition from RRC_INACTIVE

- To establish time alignment for a secondary TAG

- Request for Other SI

- Beam failure recovery

- Consistent UL Listen Before Talk (LBT) failure on SpCell

The UE may transmit a specific preamble and/or transit the specific preamble on a specific PRACH resource for the RA procedure. The specific preamble and/or the specific PRACH resource may be configured for NTN. When the UE initiates the RA procedure, the UE may not have any configured resource (e.g., type 1 and/or type 2 CG) . The NW may indicate whether the UE applies the above the criteria/conditions, e.g., via a configuration. Such an indication may be indicated via a dedicated RRC IE. (e.g., indicated in MAC-CellGroupConfig or in BSR-Config) or indicated via a broadcast system information (e.g., SIB) . When a BSR is triggered and/or when a BSR MAC CE is generated, a UE may trigger/initiate a RA procedure (for BSR) and/or set 2-step RA type for the RA procedure if the UE has been indicated/configured by the network.

The UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure in one or more of the following conditions:

- Based on satellite location information (e.g., ephemeris) , based on GNSS, and/or based on TA value: When/after the UE receives satellite location information (from the NW) , the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. When/after the UE receives satellite location information, the UE may calculate the propagation delay/RTT between the UE and the satellite. When the value of the propagation delay/RTT is greater than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. When the difference between the new calculated propagation delay/RTT and the original propagation delay/RTT is greater than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. When/after the UE receives satellite location information, the UE may calculate the UE-specific TA. When the value of the UE-specific TA is greater than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. When the difference between the new calculated UE-specific TA and the original UE-specific TA is greater than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. The UE may determine the TA value (e.g., based on a TA command) . When the value of the TA is greater than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. When the difference between the new TA value and the original TA value is greater than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. The satellite location information may be transmitted via PDCCH, Downlink Control Information (DCI) , MAC CE, and/or RRC message. The satellite location information may be transmitted via short message and/or paging message. The satellite location information may be transmitted via system information (e.g., SIB) . The satellite location information may be transmitted when the UE is in RRC_IDLE, RRC_INACTIVE, and/or RRC_CONNECTED state.

- Based on UE information (e.g., GNSS, location, the direction of movement, speed, etc. ) : When the value of UE information is greater than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. When the difference between the new UE information and the original UE information is greater than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. The UE information may be UE’s GNSS, location, the direction of movement, and/or speed, etc.

- Based on DL channel quality: The UE may detect the DL channel quality based on a DL RS (e.g., Synchronization Signal Block (SSB) and/or Channel Status Information-Reference Signal (CSI-RS) ) (e.g., based on Radio Resource Management (RRM) measurement, beam measurement, cell quality measurement, etc. ) . When the DL channel quality is less than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. When the difference between the current DL channel quality and the previous DL channel quality is greater than a threshold, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. The UE may determine whether to trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure based on UE estimates and established channel estimation techniques. The UE may determine whether to trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure based on receiving power (e.g., RSRP/Reference Signal Receiving Quality (RSRQ) ) and cell quality. The measurement may be an RRM measurement. The DL channel quality may be detected/assessed based on RSRP, RSRQ, and/or Signal to Interference plus Noise Ratio (SINR) .

- TA timer expires (and/or when TA becomes invalid) : When a TA timer expires (and/or TA is not valid) , the UE may trigger the report of UE-specific TA. The TA timer may be a specific timer for UE-specific TA. The TA timer may be timeAlignmentTimer. The TA timer may be a TA timer used for small data transmission (e.g., used in RRC_INACTIVE state) . The UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure when the UE triggers the report of UE-specific TA/and/or when the TA timer expires (and/or when TA is not valid) .

- UE leaves the source cell/gNB and camps on a new cell/gNB: The UE may move to another cell/gNB. When the UE leaves the source cell/gNB and camp on another cell/gNB, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. The source cell and the target cell may be related to different TAG.

- UL transmission (e.g., via a specific UL resource) is failed: If a UL transmission (e.g., via a specific UL resource) is failed to transmit for a number of times, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. The number may be counted by a counter. The counter may be reset when the UE successfully transmits a UL transmission (which may include the report of the UE autonomous TA/UE information/BSR) .

- A Radio Link Failure (RLF) and/or a physical layer problem is detected: When a RLC and/or a physical problem is detected, the UE may trigger/initiate a RA procedure and/or set 2-step RA type for the RA procedure. The physical layer problem may be detected, if any Dual Active Protocol Stack (DAPS) bearer is configured, upon receiving parameter N310 consecutive "out-of-sync" indications for the source SpCell from lower layers while timer T304 is running, or upon receiving parameter N310 consecutive "out-of-sync" indications for the SpCell from lower layers while neither timer T300, T301, T304, T311, T316 nor T319 are running. The RLF may be detected, upon timer T310 expires in PCell or upon timer T312 expires in PCell, or upon random access problem indication from MCG MAC while neither timer T300, T301, T304, T311 nor T319 are running, or upon indication from MCG RLC that the maximum number of retransmissions has been reached.

When the UE triggers BSR, the UE may trigger a specific SR in a case that there is no Uplink-Shared Channel (UL-SCH) resources are available for a new transmission and/or if the UL-SCH resources cannot accommodate the specific MAC CE plus its subheader as a result of LCP. After triggering the specific SR, the specific SR may be considered as pending until it is cancelled. As long as at least one SR is pending, if the UE has no valid PUCCH resources for the specific SR, the UE may initiate a RA procedure (for the BSR) . However, due to the high propagation delay/RTT, the specific SR may not be needed.

The UE may initiate the (2-step) RA procedure (e.g., the UE may skip triggering SR and/or skip transmitting SR) when one or more of the following conditions/criteria (a) - (i) are satisfied. The UE may determine not to trigger a specific SR (or use the specific SR resource for transmitting the specific SR) when one or more of the following conditions/criteria (a) - (i) are satisfied. The UE may trigger a specific SR and the UE may consider there is no valid PUCCH resources configured for the pending SR when one or more of the following conditions/criteria (a) - (i) are satisfied. The MAC entity of the UE may not instruct the physical layer of the UE to signal the SR (on one valid PUCCH resource for SR) when one or more of the following conditions/criteria (a) - (i) are satisfied. The UE may release the SR configuration and/or PUCCH resource for SR when one or more of the following conditions/criteria (a) - (i) are satisfied. The NW may not configure any SR resource (e.g., PUCCH resource for SR) to the UE when one or more of the following conditions/criteria (a) - (i) are satisfied.

(a) When a specific indication is received/configured (from NW) . The specific indication may indicate the UE could directly trigger a RA procedure (for a specific MAC CE, e.g., BSR MAC CE) without triggering an SR. The specific indication may indicate the UE not to trigger the SR or use the SR resource (for a specific MAC CE) . The specific indication may be a flag and/or a mask. The specific indication may be transmitted via DCI, MAC CE, and/or RRC message. The specific indication may be transmitted via short message and/or paging message. The specific indication may be transmitted via system information (e.g., SIB) . The specific indication may be transmitted when the UE is in RRC_IDLE, RRC_INACTIVE, and/or RRC_CONNECTED state.

(b) When the value of the (UE calculated) propagation delay/RTT is greater than a threshold.

(c) When the difference between the new calculated propagation delay/RTT and the original propagation delay/RTT is greater than a threshold.

(d) When the value of the UE-specific TA is greater than a threshold.

(e) When the difference between the new calculated UE-specific TA and the original UE- specific TA is greater than a threshold.

(f) When the DL channel quality is less than a threshold,

(g) When the difference between the current DL channel quality and the previous DL channel quality is greater than a threshold.

(h) When the UE is operating in NTN (e.g., LEO and/or GEO) . When the UE is a NTN UE. A NTN UE or a UE operating in NTN may report a specific UE capability.

(i) When the UE is configured with 2-step RA resource.

In some implementations, the specific SR may be an SR for BSR, the specific SR may be an SR for (SCell) BFR (MAC CE) . The specific SR may be an SR for LBT failure (MAC CE) . The specific SR may be an SR for UE-specific TA. The specific SR may correspond to a specific SR configuration. The specific SR may be mapped to a specific LCH.

For example, a SR configuration with a specific SchedulingRequestId and/or schedulingRequestResourceId. Such a SR configuration may be explicitly indicated by the network (e.g., indicated in SchedulingRequestToAddMod and/or SchedulingRequestResourceConfig. The MAC CE mentioned in the present disclosure may be one or more of the following MAC CE (s) :

- C-RNTI MAC CE

- Configured Grant Confirmation MAC CE

- BFR MAC CE

- Multiple Entry Configured Grant Confirmation MAC CE

- Sidelink Configured Grant Confirmation MAC CE

- LBT failure MAC CE

- MAC CE for SL-BSR prioritized

- MAC CE for BSR, with exception of BSR included for padding

- Single Entry Power Headroom Report (PHR) MAC CE or Multiple Entry PHR MAC CE

- MAC CE for the number of Desired Guard Symbols

- MAC CE for Pre-emptive BSR

- MAC CE for SL-BSR, with exception of SL-BSR prioritized and SL-BSR included for padding

- MAC CE for Recommended bit rate query

- MAC CE for BSR included for padding

- MAC CE for SL-BSR included for padding

- UE autonomous TA report

The UE may cancel the pending SR when/after the UE (successfully) transmits the BSR and/or some MAC CE (s) , e.g., over 2-step RA and/or MsgA PUSCH and/or when the corresponding RA procedure is successfully completed.

The UE-specific TA may be referred to UE autonomous TA and/or (UE) pre-compensation TA. The UE-specific TA (and/or UE information) may be reported via an RRC signalling (e.g., RRC message) , a MAC signalling (e.g., MAC CE) , and/or a PHY signalling (e.g., via Uplink Control Information (UCI) ) . The report of UE-specific TA (and/or UE information) may be transmitted via PRACH, PUCCH, PUSCH. The report of UE-specificTA (and/or UE information) may include one or more of (but not limited to) the following information:

- TA (including UE specific TA and common TA)

- Full propagation delay (e.g., RTT between UE and gNB)

- UE specific delay, based on the UE-specific distance to the reference point

- Common delay compensation, where the delay includes the feeder link delay + delay from the satellite to a reference point (for example, the center of a beam/cell) . This delay may be broadcasted by the network, and the UE may use this value for timing pre-compensation.

- UE-specific delay compensation, where the delay includes the feeder-link delay + UE specific delay calculated by the UE via e.g., distance from the UE to the satellite. The feeder link delay may be broadcasted, and the UE may add the calculated UE-specific value to obtain the full RTD for timing pre-compensation

- UE-specific frequency offset

- Full frequency offset

- UE’s location, the direction of movement, and/or speed, etc.

- The UE may report the absolute value for UE-specificTA (and/or UE information) . The UE may report a delta value (comparing to the previous reports) for UE-specificTA (and/or UE information)

The report of UE-specific TA (and/or UE information) may be a UE capability and/or UE assistance information. When the report of UE-specific TA (and/or UE information) is triggered and there is no available UL resource (and/or the UL resource could not accommodate the report of UE autonomous TA/UE information) , the UE may trigger a specific SR and/or trigger a RA procedure. When the report of UE-specific TA (and/or UE information) is transmitted, the UE may cancel the triggered report of UE-specific TA (and/or UE information) , cancel the pending SR (triggered by the report of UE autonomous TA) , and/or stop the RA procedure (initiated for the report of UE autonomous TA/UE information) . When the UE triggers the report of UE-specific TA (and/or UE information) , generates the report/MAC CE of UE-specific TA (and/or UE information) , and/or transmits the report of UE-specific TA (and/or UE information) to the NW, the UE may consider the TA is valid (e.g., start/restart the TA timer) or invalid (e.g., consider the TA timer expires) . The new criterion (s) for triggering/initiating a RA procedure and/or a new criterion (s) to set 2-step RA type for the RA procedure may be applied to terrestrial network (TN) and/or NTN.

Table 5 below includes an example of a selection of a RA type. RA types may be 2-step or 4-step RA and how to select a RA type in Rel-16 is provided in Table 5.

Table 5

In NR, it may be possible to only configure with 2-step RA resource in a serving cell or a UE (e.g., 4-step RA resource is not configured) . However, considering the MsgA PUSCH resource requirement on top of Preamble index, the 2-step RA capacity may be less than the 4-step RA capacity. For NTN with the typical cell size up to 1000 km in GEO and 200km in LEO, the 2-Step RA capability may not achieve the required UE density without 4-step RA resources. If both 2-step and 4-step RA type Random Access Resources are configured in a cell, the legacy RA type selection may be determined by UE based on the RSRP measurement and the threshold configured by the NW. However, since no near-far effect in NTN, all UEs in an NTN cell may have similar RSRP levels. Hence, all UEs in a cell may select 2-step RACH RA type or select 4-step RACH RA type only. In some cases, an NTN cell may have limited RSRP difference amount UEs. It implies that even if NW intends to configure both 2-step RACH RA and 4-step RACH RA types, it may lead to a single RA type in an NTN cell. The worst-case could be when NW only configures 2-step RACH RA (i.e., no 4-step RACH RA) in a cell, there might be no UE could have RSRP above the msgA-RSRP-Threshold to trigger a RA.

FIG. 9 is a schematic diagram illustrating the impact of elevation angles and the corresponding RSRP in a cell according to an example implementation of the present disclosure. Strong RSRP 904 occurs when a satellite 901 is on top of a UE 902, and weak RSRP 905 happens when the satellite 901 has a small elevation angle. There are two reasons behind. First, the propagation distance gets longer when the elevation angle decreases, that weakens signal strength due to transmission distance. Second, Line-Of-Sight (LOS) probability is smaller as the elevation angle decreases, that weakens signal due to possible blocking on earth 903. Especially, for an earth-fixed cell, the RSRP level varies in time and UEs would experience the best (90 degrees of elevation) and the worst (10 degrees of elevation) RSRP quality during the service. In other words, the NW would experience a burst request from the UEs for either 2-step or 4-step RACH RA type.

To make NW scheduling easy, the NW may provide new guidelines, i.e., on top of the RSRP determination for 2-step RA type, for example, when the elevation angle equal to 90 degrees with a good quality of RSRP such that all served UEs may support 2-step RACH RA type, i.e., no UE would select 4-step RACH RA type, NW may provide a new indication in system information, e.g., SIB1, to force some of the UEs to select between 2-step RACH RA type and 4-step RACH RA type randomly. A probability of P may be configured by the network via dedicated signalling (e.g., RRC signaling) or broadcast system information (e.g., SIB1) . Subsequently, a UE may select 4-step (or 2-step) RA type with a probability of P, and select 2-step (or 4-step) RA type with a probability of 1-P. For example, if a configured P value is 0.3, a UE may select 4-step (or 2-step) RA type with a probability of 30%and select 2-step (or 4-step) RA type with a probability of 70% (i.e., 1-P is 0.7 in this example) .

If a BWP selected for RA procedure is configured with both 2-step RA resource and 4-stpe RA resource (and/or the RSRP is above msgA-RSRP-Threshold) , the UE may randomly select the 2-step RA type or 4-step RA type. Whether the UE randomly selects the 2-step RA type or 4-stpe RA type may be configured by the NW (e.g., based on an NW indication) . The NW indication for random selection between 2-step and 4-step RA types may be configured in system information. A first value (e.g., “0” ) may indicate no random selection and a second value (e.g., “1” ) may indicate random selection between 2-step and 4-step RA types. The NW indication may be configured via a UE-specific/dedicated configuration (e.g., an RRC configuration) . The NW indication may be a flag. The NW indication may be transmitted via DCI, MAC CE, and/or RRC.

If a BWP selected for RA procedure is configured with both 2-step RA resource and 4-stpe RA resource (and/or the RSRP is above msgA-RSRP-Threshold) , the UE may only set the RA_TYPE to 4-step and/or 2-step based on an NW indication. The NW indication may indicate that the UE may set the RA_TYPE to 4-step and/or 2-step. The NW indication may be a flag. The NW indication may be transmitted via DCI, MAC CE, and/or RRC.

If a BWP selected for RA procedure is configured with both 2-step RA resource and 4-stpe RA resource (and/or the RSRP is above msgA-RSRP-Threshold) , the UE may be configured with a criterion, a scaling factor, and/or a probability for the selection between the 2-step RA type and 4-step RA type.

The UE may ignore and/or not consider the RARP threshold for MsgA (e.g., for 2-step RA type selection) to set the RA type when the UE is operating in NTN. The NW may not configure the RSRP threshold for MsgA (e.g., msgA-RSRP-Threshold) to NTN UE. An NTN UE and/or a UE operates in NTN may set the RA_TYPE to 2-stepRA or 4-stepRA randomly if it has been configured with both 2-step RA and 4-step RA. An NTN UE and/or a UE operates in NTN may report a specific UE capability.

II. HARQ process ID selection for CG and/or SPS

The HARQ process ID used for UL CG transmission and/or DL Semi-Persistent Scheduling (SPS) reception may be derived/selected based on an equation without an offset, an equation with an offset, or UE implementation to select a HARQ Process ID among the HARQ process IDs available for the configured grant configuration.

The HARQ Process ID for UL CG may be provided in the following. For configured uplink grants neither configured with harq-ProcID-Offset2 nor with cg-RetransmissionTimer, the HARQ Process ID associated with the first symbol of a UL transmission may be derived from the following equation:

HARQ Process ID = [floor (CURRENT_symbol /periodicity) ] modulo nrofHARQ-Processes

For configured uplink grants with harq-ProcID-Offset2, the HARQ Process ID associated with the first symbol of a UL transmission may be derived from the following equation.

HARQ Process ID = [floor (CURRENT_symbol /periodicity) ] modulo nrofHARQ-Processes + harq-ProcID-Offset2,

Where CURRENT_symbol = (SFN × numberOfSlotsPerFrame ×numberOfSymbolsPerSlot + slot number in the frame × numberOfSymbolsPerSlot + symbol number in the slot) , and numberOfSlotsPerFrame and numberOfSymbolsPerSlot refer to the number of consecutive slots per frame and the number of consecutive symbols per slot, respectively as specified in the 3GPP TS 38.211. Also, SFN refers to the System Frame Number.

For configured uplink grants configured with cg-RetransmissionTimer, the UE implementation selects a HARQ Process ID among the HARQ process IDs available for the configured grant configuration. The UE may prioritize retransmissions before initial transmissions. The UE may toggle the NDI in the CG-Uplink Control Information (UCI) for new transmissions and may not toggle the NDI in the CG-UCI in retransmissions.

The HARQ Process ID for DL SPS may be provided in the following. For configured downlink assignments without harq-ProcID-Offset, the HARQ Process ID associated with the slot where the DL transmission starts may be derived from the following equation:

HARQ Process ID = [floor (CURRENT_slot × 10 / (numberOfSlotsPerFrame ×periodicity) ) ] modulo nrofHARQ-Processes,

Where CURRENT_slot = [ (SFN × numberOfSlotsPerFrame) + slot number in the frame] and numberOfSlotsPerFrame refers to the number of consecutive slots per frame as specified in the 3GPP TS 38.211.

For configured downlink assignments with harq-ProcID-Offset, the HARQ Process ID associated with the slot where the DL transmission starts may be derived from the following equation.

HARQ Process ID = [floor (CURRENT_slot /periodicity) ] modulo nrofHARQ-Processes + harq-ProcID-Offset,

Assuming that the HARQ feedback/HARQ retransmission for some of the HARQ processes are disabled and the HARQ feedback/HARQ retransmission for the other HARQ processes are enabled, there may be problems if the HARQ process ID for CG/SPS transmission is also derived based on the formula as specified in the 3GPP TS 38.321. For example, for a CG/SPS configuration, it may not be guaranteed that each transmission via the resource configured by the CG/SPS configuration is transmitted via a UL/DL HARQ process ID with enabled or disabled HARQ feedback/HARQ retransmission. In a case that the UE needs to derive a HARQ process ID for an SPS/CG transmission, the UE may derive a HARQ process ID for which HARQ feedback/HARQ retransmission is enabled/disabled for the SPS/CG transmission.

In some implementations, a parameter/IE (e.g., a flag) may be configured by the NW to indicate whether the SPS/CG configuration is allowed to be mapped to a HARQ process with enabled and/or disabled HARQ feedback/HARQ retransmission. For example, the UE may be configured with a HARQ process 0 to 3 (e.g., the first set/group of HARQ processes) with enabled HARQ feedback/HARQ retransmission and HARQ process 4 to 15 (e.g., the second set/group of HARQ processes) with disabled HARQ feedback/HARQ retransmission. The UE may be configured with an SPS/CG configuration. If the parameter/IE indicates that the SPS/CG configuration is allowed to be mapped to a HARQ process with enabled HARQ feedback/HARQ retransmission, the UE may select the HARQ process ID 0 to 3 (e.g., the first set of HARQ processes) to perform the SPS/CG transmission for the SPS/CG configuration. If the parameter/IE indicates that the SPS/CG configuration is not allowed to be mapped to a HARQ process with disabled HARQ feedback/HARQ retransmission, the UE may use the HARQ process ID 4 to 15 (e.g., the second set of HARQ processes) to perform the SPS/CG transmission for the SPS/CG configuration. If the parameter/IE indicates that the SPS/CG configuration is allowed to be mapped to a HARQ process with both enabled and disabled HARQ feedback/HARQ retransmission (or if there is no restriction or if the parameter/IE is not configured) , the UE may use all of the HARQ process IDs to perform the SPS/CG transmission for the SPS/CG configuration. If the parameter is not configured, the UE may select any of the HARQ process IDs (e.g., by UE implementation) , select the HARQ process IDs based on a formula, and/or select a default HARQ process ID (e.g., configured by the NW) .

In some implementations, a parameter/IE (e.g., a list) may be configured by the NW to indicate whether a HARQ process or a set of HARQ processes supports SPS/CG transmission. For example, the UE may be configured with HARQ processes 0 to 3 (e.g., the first set/group of HARQ processes) with enabled HARQ feedback/HARQ retransmission and HARQ processes 4 to15 (e.g., the second set of HARQ processes) with disabled HARQ feedback/HARQ retransmission. The UE may be configured with an SPS/CG configuration. If the parameter/IE indicates a HARQ process or a set of HARQ processes supports SPS/CG transmission, the UE may select/derive the HARQ process ID for the SPS/CG transmission from the HARQ process or the set of HARQ processes to perform the SPS/CG transmission. The UE may not select the HARQ process ID (s) and/or another set of HARQ processes which does not support SPS/CG transmission to perform the SPS/CG transmission. If the parameter/IE is not configured, the UE may select any of the HARQ process IDs (e.g., by UE implementation) , select the HARQ process IDs based on a formula, and/or select a default HARQ process ID (e.g., configured by the NW) .

In some implementations, a parameter/IE (e.g., an offset and/or a threshold) may be configured by the NW to be used for (the formula of) the HARQ process ID derivation for SPS/CG. For example, the parameter/IE may indicate a value, and the UE may select/derive the HARQ process ID which is equal to or greater than the value to be used for SPS/CG transmission. Otherwise, the UE may select/derive the HARQ process ID which is equal to or less than the value to be used for SPS/CG transmission. For example, the parameter/IE may be used for a new formula for HARQ process ID derivation for SPS/CG. The parameter may not be the harq-ProcID-Offset and/or harq-ProcID-Offset2 as specified in the 3GPP TS 38.321.

The new formula may be provided as follows:

HARQ Process ID = [floor (CURRENT_symbol /periodicity) ] modulo (nrofHARQ-Processes +/-a value indicated by the parameter/IE) , or

HARQ Process ID = [floor (CURRENT_symbol /periodicity) ] modulo a value indicated by the parameter/IE

In some circumstances (e.g., for the NTN) , the formula for HARQ process ID derivation for SPS/CG (e.g., as specified in the 3GPP TS 38.321) may not be applied. The UE may apply the method for HARQ process ID derivation described in the present disclosure. If the UE operates in the NTN, the formula for HARQ process ID derivation for SPS/CG may not be applied. The UE may apply the method for HARQ process ID derivation described in the present disclosure. If the UE connects with an NTN beam, cell, and/or BS, the formula for HARQ process ID derivation for SPS/CG may not be applied. The UE may apply the method for HARQ process ID derivation described in the present disclosure. If the UE reports a capability for NTN, the formula for HARQ process ID derivation for SPS/CG may not be applied. The UE may apply the method for HARQ process ID derivation described in the present disclosure. If the UE has a HARQ process (s) which HARQ feedback/HARQ retransmission is disabled, the formula for HARQ process ID derivation for SPS/CG may not be applied. The UE may apply the method for HARQ process ID derivation described in the present disclosure. If the UE is configured with the parameter/IE mentioned in the present disclosure, the formula for HARQ process ID derivation for SPS/CG may not be applied. The UE may apply the method for HARQ process ID derivation described in the present disclosure.

The parameter may be used to indicate whether the SPS/CG configuration is allowed to be mapped to a HARQ process with enabled and/or disabled HARQ feedback/HARQ retransmission. The parameter may be used to indicate whether a HARQ process or a set of HARQ processes supports SPS/CG transmission The parameter may be an offset and/or a threshold used for (the formula of) the HARQ process ID derivation for SPS/CG.

Assuming that a CG is configured to support HARQ process (es) with enabled/disabled HARQ feedback/HARQ retransmission (e.g., the CG transmission may be transmitted using a HARQ process with enabled/disabled HARQ feedback/HARQ retransmission) . If there is a (UL) data (e.g., MAC PDU, TB) to be transmitted, the UE may determine whether to use the CG associated with the HARQ process (es) with enabled/disabled HARQ feedback/HARQ retransmission based on some criteria. If the UE determines not to use the CG for transmitting the data, the UE may skip the CG transmission.

The UE may determine whether to use the CG associated with the HARQ process (es) with enabled/disabled HARQ feedback/HARQ retransmission based on the content included in the data. The content may be a specific RRC message, a specific MAC CE, and/or etc. If the data includes a specific RRC message and/or a specific MAC CE, the UE may select a HARQ process ID which is enabled for HARQ feedback/HARQ retransmission. If the data does not include a specific RRC message and/or a specific MAC CE, the UE may select a HARQ process ID which is disabled for HARQ feedback/HARQ retransmission.

In some implementations, the UE may determine whether to use the CG associated with the HARQ process (es) with enabled/disabled HARQ retransmission based on the LCH/Data Radio Bearer (DRB) /Signaling Radio Bearer (SRB) from which the data comes. For example, if the data comes from a first LCH/DRB/SRB, the UE may select a HARQ process ID which is enabled for HARQ retransmission to transmit the data from the first LCH/DRB/SRB. If the data comes from a second LCH/DRB/SRB, the UE may select a HARQ process ID which is disabled for HARQ retransmission to transmit the data from the second LCH/DRB/SRB. How to map/associate the LCH/DRB/SRB to the HARQ process may be configured by the NW.

How to select the HARQ process ID from a set of HARQ processes with enabled/disabled HARQ feedback/HARQ retransmission may be based on the time occasion (e.g., symbol, slot) for the SPS/CG transmission, based on periodicity (of the SPS/CG) , and/or based on a number of HARQ processes of the set. How to select the HARQ process ID from a set of HARQ processes with enabled/disabled HARQ feedback/HARQ retransmission may be based on UE implementation. If at least one HARQ process ID has had its HARQ feedback/HARQ retransmission disabled at a UE, an HARQ ID for each UL resource that corresponds to a CG configuration may be selected based on UE implementation. The UE may select an enabled/disabled HARQ ID. The parameter/IE may be configured in an SPS/CG configuration.

The parameter/IE may be a flag (e.g., 1 bit) . A first value (e.g., 0) of the flag may indicate the SPS/CG configuration is allowed to be mapped to a HARQ process with enabled HARQ feedback/HARQ retransmission. A second value (e.g., 1) of the flag may indicate the SPS/CG configuration is allowed to be mapped to a HARQ process with disabled HARQ feedback/HARQ retransmission. If a specific parameter/IE has been configured for a CG configuration, a HARQ ID for each UL resource that corresponds to this CG configuration may be selected based on UE implementation. In some implementations, if a flag indicates a CG is allowed to be mapped to a HARQ process with enabled HARQ feedback/HARQ retransmission, a HARQ ID for each UL resource that corresponds to this CG configuration may be selected based on UE implementation. If a flag indicates a CG is allowed to be mapped to a HARQ process with enabled HARQ feedback/HARQ retransmission, the UE may only select a HARQ process ID with enabled HARQ feedback/HARQ retransmission. In some implementations, if a flag indicates a CG is allowed to be mapped to a HARQ process with disabled HARQ feedback/HARQ retransmission, a HARQ ID for each UL resource that corresponds to this CG configuration may be selected based on UE implementation. If a flag indicates a CG is allowed to be mapped to a HARQ process with enabled HARQ feedback/HARQ retransmission, the UE may only select a HARQ process ID with disabled HARQ feedback/HARQ retransmission. It may be noted that a UE may indicate (via UCI) the HARQ process ID of a UL resource that corresponds to a CG configuration if the UE selects the HARQ process ID of the UL resource by itself.

The set of HARQ processes may be configured by a list. The HARQ processes IDs in the set may be continuous or not continuous. The set of HARQ processes may be (or configured to be) available or not available for SPS/CG configuration. The HARQ process related to an enabled HARQ feedback/HARQ retransmission or related to a disabled HARQ feedback/HARQ retransmission may be configured by the NW. The parameter/IE may be configured when the UE is operated in the NTN. The parameter may be configured when at least one HARQ process for the UE is disabled for its HARQ feedback/HARQ retransmission. The parameter/IE may not be configured when all of the HARQ process are enabled for HARQ feedback/HARQ retransmission. A parameter/IE configured for SPS and a parameter/IE configured for CG may be the same (value) or different (values) . The parameter/IE may be configured on a per LCH, per HARQ process, per UE, per BWP, and/or per cell basis. The parameter/IE configured for different SPS/CG configurations may be different (values) . The parameter/IE may only be configured if the HARQ process has had its HARQ feedback/HARQ retransmission enabled/disabled on a per HARQ basis. The parameter/IE may not be configured if the HARQ process has had its HARQ feedback/HARQ retransmission enabled/disabled on a per UE basis. When the UE selects a HARQ process (ID) for CG transmission based on methods in the present disclosure, the UE may report/indicate the CG transmission using which HARQ process (ID) to the NW, e.g., by UCI.

III. LCH and/or MAC CE mapping to a HARQ process

In MAC layer, to perform multiplexing and assembly procedure for generating a MAC Protocol Data Unit (PDU) for (UL) transmission, the UE may perform a Logical Channel Prioritization (LCP) , which includes a selection of an LCH and allocation of resources. Furthermore, the UE may perform multiplexing of MAC Control Elements (MAC CEs) and MAC Service Data Units (SDUs) to a MAC PDU.

In LCP, when a new transmission is performed (e.g., based on CG, DG, RAR grant, and/or MsgA PUSCH) , the UE may select the logical channels for each UL grant that satisfy (all) the following conditions (noted that the parameters/IEs for the conditions may be configured in LogicalChannelConfig, which means the parameters may be configured on a per-LCH basis) :

-The set of allowed Subcarrier Spacing index values in allowedSCS-List, if configured, includes the Subcarrier Spacing index associated to the UL grant.

- maxPUSCH-Duration, if configured, is greater than or equal to the PUSCH transmission duration associated to the UL grant.

- configuredGrantType1Allowed, if configured, is set to true in case the UL grant is a Configured Grant Type 1.

- allowedServingCells, if configured, includes the Cell information associated with the UL grant. Does not apply to logical channels associated with a Data Radio Bearer (DRB) configured with PDCP duplication within the same MAC entity (i.e., CA duplication) for which PDCP duplication is deactivated.

- allowedCG-List, if configured, includes the configured grant index associated with the UL grant; and

- allowedPHY-PriorityIndex, if configured, includes the priority index (as specified in the 3GPP TS 38.213) associated to the dynamic UL grant.

In allocation of resources, when a new transmission is performed, the UE may allocate resources to the logical channels selected based on LCP (for each UL grant that satisfy (all) the following conditions mentioned in the present disclosure) . Additionally, data from LCHs (e.g., MAC SDU) and/or MAC CEs may be prioritized in accordance with the following order.

- C-RNTI MAC CE or data from UL-Common Control Channel (CCCH)

- Configured Grant Confirmation MAC CE or Beam Failure Recovery (BFR) MAC CE or Multiple Entry Configured Grant Confirmation MAC CE

- Sidelink Configured Grant Confirmation MAC CE

- Listen Before Talk (LBT) failure MAC CE

- MAC CE for Sidelink-Buffer Status Report (SL-BSR) prioritized

- MAC CE for BSR, with exception of BSR included for padding

- Single Entry Power Headroom Report (PHR) MAC CE or Multiple Entry PHR MAC CE

- MAC CE for the number of Desired Guard Symbols

- MAC CE for Pre-emptive BSR

- Data from any Logical Channel, except data from UL-CCCH

- MAC CE for Recommended bit rate query

- MAC CE for BSR included for padding

- MAC CE for SL-BSR included for padding

- Prioritization among Configured Grant Confirmation MAC CE, Multiple Entry Configured Grant Confirmation MAC CE, and BFR MAC CE may be up to UE implementation.

How to map a data from an LCH to a UL grant could be controlled by LCP restriction/operation (e.g., based on the parameters/IEs configured by NW for LCP conditions to select the LCHs) . How to map a MAC CE to a UL grant may follow the priority order as mentioned in the present disclosure.

For a DL transmission based on a DL assignment which is transmitted via a disabled HARQ process (e.g., a HARQ process without HARQ feedback) , some specific UE behaviors may need to be performed, e.g., when/after receiving an indication (e.g., RRC configuration) to disable the HARQ feedback of a HARQ process which is used for the DL transmission. For a UL transmission based on a UL grant (e.g., CG, DG, RAR grant, MsgA PUSCH) which is transmitted via a disabled HARQ process (e.g., a HARQ process without HARQ retransmission) , some specific UE behaviors may need to be performed, e.g., when/after receiving an indication (e.g., RRC configuration) to disable the HARQ retransmission of a HARQ process which is used for the UL transmission.

The UE may receive one or more of the following (RRC) configurations to indicate the states of the HARQ process from the network (NW) .

The states of HARQ feedback for a HARQ process (for DL) are described as follows:

- First state of HARQ feedback for a HARQ process (for DL) : Enable HARQ feedback for a HARQ process (es) . HARQ feedback (Acknowledgement (ACK) /Negative Acknowledgement (NACK) ) for a HARQ process may be enabled by the NW. The UE may need to send the HARQ feedback (ACK/NACK) for a HARQ process if the HARQ feedback for the HARQ process is enabled. The UE may (re) start a DRX timer (e.g., drx-HARQ-RTT-TimerDL) for the HARQ process if the HARQ feedback for the HARQ process is enabled.

- Second state of HARQ feedback for a HARQ process (for DL) : Disable HARQ feedback for a HARQ process (es) . HARQ feedback (ACK/NACK) for a HARQ process may be disabled by the NW.The UE may not send the HARQ feedback (ACK/NACK) for a HARQ process if the HARQ feedback for the HARQ process is disabled. The UE may not (re) start a DRX timer (e.g., drx-HARQ-RTT-TimerDL) for the HARQ process if the HARQ feedback for the HARQ process is disabled.

The states of HARQ retransmission for a HARQ process (for UL) are described as follows:

- First state of HARQ retransmission for a HARQ process (for UL) : Enable HARQ retransmission for a HARQ process (es) . HARQ retransmission for a HARQ process may be enabled by the NW. The UE may (re) start a DRX timer (e.g., drx-HARQ-RTT-TimerUL) for the HARQ process if the HARQ retransmission for the HARQ process is enabled. The UE may extend the length of a DRX timer (e.g., drx-HARQ-RTT-TimerUL) , e.g., by UE-gNB RTT, if the HARQ retransmission for the HARQ process is enabled.

- Second state of HARQ retransmission for a HARQ process (for UL) : Disable HARQ retransmission for a HARQ process (es) . The UE may not (re) start a DRX timer (e.g., drx-HARQ-RTT-TimerUL) for the HARQ process if the HARQ retransmission for the HARQ process is disabled. The UE may not extend the length of a DRX timer (e.g., drx-HARQ-RTT-TimerUL) , e.g., by UE-gNB RTT, if the HARQ retransmission for the HARQ process is disabled.

For UL transmission, when there is a new transmission based on a UL grant, the UE may select the LCH (s) (based on LCP) and multiplex the data from the selected LCH (s) to the UL grant. If the UL grant is a configured grant (CG) , the UE may select/derive a HARQ process (ID) to perform the new transmission based on a formula. If the UL grant is a DG, the NW may indicate which HARQ process (ID) should be used for the new transmission, e.g., via a DCI field to (explicitly) indicate the HARQ process ID. When there is a UL grant (e.g., CG and/or DG) , the UE may use a HARQ process for the UL transmission based on the UL grant. However, which data (e.g., from which LCH (s) ) may be multiplexed in the MAC PDU for the UL transmission may be based on LCP conditions. That is, it is possible that data from one or more than one LCH (s) may be multiplexed into a MAC PDU and may be transmitted via a UL resource using a specific HARQ process.

It is noted that the data from different LCHs may be associated with different requirements (e.g., Quality of Service (QoS) requirements) . Also, the priorities of transmission for different LCHs may be different. For example, the data from some LCHs may need higher reliability. It is beneficial to multiplex data from LCHs which need higher reliability to a UL transmission via the HARQ process (es) with an enabled HARQ process (i.e., the HARQ process is enabled HARQ retransmission) , and multiplex data from LCHs which may not need higher reliability to a UL transmission via the HARQ process (es) with a disabled HARQ process (i.e., the HARQ process is disabled HARQ retransmission) .

How to map a MAC CE to a UL transmission may follow the priority order as mentioned in the present disclosure. However, some important MAC CEs may include important information, e.g., C-RNTI MAC CE or data from UL-CCCH, Configured Grant Confirmation MAC CE, BFR MAC CE, and/or LBT failure MAC CE, etc. The reliability of the transmission of the MAC PDU which includes these MAC CE (s) may be critical. Therefore, it may be beneficial to multiplex some important MAC CE (s) to a UL transmission via the HARQ process (es) with an enabled HARQ process (i.e., the HARQ process is enabled HARQ retransmission) .

In some implementations, an indication (e.g., indicated/configured by the NW) may be used to indicate whether a specific LCH (s) and/or MAC CE (s) is allowed to be selected for a (new) transmission using a specific HARQ process based on a state of the HARQ process (e.g., whether HARQ retransmission is enabled/disabled for the HARQ process) . The UE may select one or multiple LCH(s) and/or MAC CE (s) for the UL transmission using the specific HARQ process based on the indication/configuration.

If the UL grant is a DG, the UE may know the UL transmission based on the DG could be transmitted via which HARQ process (e.g., based on a DCI field of the DG) . The UE may select one or more LCH (s) and/or MAC CE (s) to allocate the resource of the DG based on the state, the indication and/or the information of the HARQ process (e.g., HARQ process ID/list and/or whether the HARQ retransmission is enabled/disabled) . If the UL grant is a CG, the UE may derive/select a HARQ process ID based on a formula for the transmission of the CG. The UE may select one or more LCH (s) and/or MAC CE (s) to allocate the resource of the CG based on the state, the indication and/or the information of the HARQ process (e.g., HARQ process ID/list and/or whether the HARQ retransmission is enabled/disabled) . If the UL grant is a RAR grant, the HARQ process ID for the transmission of the RAR grant may be a specific HARQ process (e.g., HARQ process 0) . The UE may select one or more LCH (s) and/or MAC CE (s) to allocate the resource of the RAR grant based on the indication to determine whether the LCH (s) and/or MAC CE (s) could be selected for the specific HARQ process (e.g., HARQ process 0 and/or with a first state/asecond state) .

The indication may be a list (e.g., allowedHARQ-List) to include the HARQ process ID (s) . The indication may indicate whether one or multiple HARQ process (es) (which is used for transmission of the UL grant) could be used for a specific LCH and/or MAC CE (s) based on a state of the HARQ process. The indication may include the HARQ process information (e.g., HARQ process IDs) . For example, the indication may include HARQ process 1 and HARQ process 2 for an LCH (s) and/or MAC CE (s) . When the UE performs a (new) transmission based on a UL grant, the UE may (only) select the indicated LCH (s) and/or MAC CE (s) to allocate the resource of the UL grant if the transmission based on the UL grant is transmitted via HARQ process 1 and/or HARQ process 2. The UE may not select the LCH (s) and/or MAC CE (s) to allocate the resource of the UL grant if the transmission based on the UL grant is transmitted via HARQ process 3. For example, if the indication (e.g., the list) is configured for an LCH and none of the HARQ process ID (s) are disabled, UL data from this LCH may be mapped to a UL resource (of a CG or DG) that corresponds to any HARQ process ID. More specifically, the UE may ignore the indication if the UE is not configured with disabled HARQ process.

The indication may be a flag (e.g., allowedHARQenable and/or allowedHARQdisable) to indicate whether the LCH (s) and/or MAC CE (s) is allowed to be associated to a HARQ process based on a state of the HARQ process (e.g., whether the HARQ retransmission for the HARQ process is enabled/disabled) . If the indication indicates the LCH (s) and/or MAC CE (s) is allowed to be mapped to a first state of HARQ process (e.g., with enabled HARQ retransmission) , the UE may select this LCH (s) and/or MAC CE (s) for the UL transmission via a HARQ process with the first state (e.g., with enabled HARQ retransmission) . If the indication indicates the LCH (s) and/or MAC CE (s) is allowed to be mapped to a second state of a HARQ process (e.g., with disabled HARQ retransmission) , the UE may select this LCH (s) and/or MAC CE (s) for the UL grant which is transmitted via a HARQ process with the second state (e.g., with disabled HARQ retransmission) . If the indication indicates the LCH (s) and/or MAC CE (s) is allowed to be mapped to a HARQ process with the first state and the second state, the UE may select this LCH (s) and/or MAC CE (s) for the UL transmission via a HARQ process with the first state or a HARQ process with the second state.

The indication may indicate one of two values (e.g., 0/1, allowed/disallowed, and/or enable/disable) . If the indication indicates a first value (e.g., 0, allowed, and/or enable) for an LCH (s) and/or MAC CE (s) , when the UE performs a (new) transmission based on a UL grant, the UE may select the LCH (s) and/or MAC CE (s) for the UL transmission via a HARQ process with a first state (e.g., with enabled HARQ retransmission) . The UE may not select the LCH (s) and/or MAC CE (s) for the UL transmission via a HARQ process with a second state (e.g., with disabled HARQ retransmission) . If the indication indicates a second value (e.g., 1, disallowed, and/or disable) for an LCH (s) and/or MAC CE (s) , when the UE performs a (new) transmission based on a UL grant, the UE may select the LCH (s) and/or MAC CE (s) for the UL transmission via a HARQ process with a second state (e.g., with disabled HARQ retransmission) . The UE may not select the LCH (s) and/or MAC CE (s) for the UL transmission via a HARQ process with a first state (e.g., with enabled HARQ retransmission) . The indication (e.g., a flag) may be configured for an LCH to associate the LCH to (aset of) disabled HARQ (s) process. UL data from this LCH may be mapped to a UL resource with any HARQ process ID in the case that the state of the HARQ process is not configured and/or none of the HARQ process ID (s) are disabled) . More specifically, the UE may ignore the indication if the UE is not configured with disabled HARQ process and/or if the UE is not configured with the state of the HARQ process.

The indication may be a threshold (e.g., to indicate a value) for the selection of LCH and/or MAC CE for a UL transmission using a HARQ process. The LCH (s) ID and/or MAC CE (and/or its priority index) which is higher or less than the threshold may be selected for a (new) transmission (based on a UL grant) which is transmitted via a specific HARQ process with a first state (e.g., enabled HARQ retransmission) and/or a second state (e.g., disabled HARQ retransmission) . The priority index may be based on an IE priority configured in LogicalChannelConfig. The priority (index) may be configured per LCH and/or MAC CE. The priority may be used for comparison of the priority between LCHs and MAC CEs. For example, assuming that the indication indicates a threshold/value, when the UE performs a (new) transmission based on a UL grant, the UE may (only) select the LCH and/or MAC CE whose ID and/or priority (index) is greater than the indicated threshold/value for a UL transmission via a HARQ process with a first state (e.g., enabled HARQ retransmission) . The UE may not select the LCH and/or MAC CE whose ID and/or priority (index) is less than the indicated threshold/value for the UL transmission via a HARQ process with a second state (e.g., disabled HARQ retransmission) .

The indication may indicate one or more LCHs and/or MAC CEs (e.g., via a list) that may be selected for a (new) transmission of a UL transmission via a specific HARQ process (ID) with a first state (e.g., enabled HARQ retransmission) and/or a second state (e.g., disabled HARQ retransmission) . The indication may include LCH ID (s) . The indication may indicate one or more kinds of MAC CE (s) . For example, assuming that the indication indicates LCH 1 and LCH 2 and/or indicates that the LCH 1 and LCH2 are allowed to be mapped to a HARQ process with a first state (e.g., enabled HARQ retransmission) , when the UE performs a (new) transmission for a UL transmission, the UE may select the LCH 1 and/or LCH 2 to allocate the resource of the UL transmission for the HARQ process with the first state. The UE may not select the LCH 3 to allocate the resource for the UL transmission for the HARQ process with the first state. For example, assuming that the indication indicates a first MAC CE and a second MAC CE are allowed to be mapped to a HARQ process with a first state (e.g., enabled HARQ retransmission) , when the UE performs a (new) transmission for a UL transmission, the UE may select the first MAC CE and the second MAC CE to allocate the resource of the UL transmission for the HARQ process with the first state. The UE may not select the third MAC CE to allocate the resource for the UL transmission for the HARQ process with the first state.

In some implementations, one or more, or all, LCH (s) and/or MAC CEs may (only) be allowed to be transmitted on a UL transmission via a specific HARQ process (ID) with a first state (e.g., with enabled HARQ retransmission) . One or more, or all, LCH (s) and/or MAC CEs may (only) be allowed to be transmitted via a specific HARQ process with a first state (e.g., a specific HARQ process with enabled HARQ retransmission, and/or the specific HARQ process is HARQ process 0) . One or more, or all, LCH (s) and/or MAC CEs may (only) be allowed to be transmitted via a UL transmission scheduled by a specific UL grant (e.g., CG, DG, RAR grant, and/or MsgA PUSCH) .

In some implementations, data from UL-CCCH may (only) be mapped to a HARQ process with a first state (e.g., with enabled HARQ retransmission) . Data from UL-CCCH may not be mapped to a HARQ process with a second state (e.g., with disabled HARQ retransmission) . In some implementations, a specific HARQ process (e.g., the HARQ process 0) may be configured as a HARQ process with a first state (e.g., with enabled HARQ retransmission) . The specific HARQ process (e.g., the HARQ process 0) may not be configured as a HARQ process with a second state (e.g., with disabled HARQ retransmission) . The specific HARQ process (e.g., the HARQ process 0) may not be allowed to disable its HARQ retransmission or set as the second state.

The indication may be configured by a configuration included in LogicalChannelConfig. The indication may be a parameter/IE for LCP. The indication may be configured by a configuration for the NTN. The indication may be configured per LCH, per HARQ process, per Bandwidth Part (BWP) , per serving cell, and/or per UE. The indication may be configured by the NW. The indication may be configured when the UE is operated in the NTN. The parameter/IE may be configured when at least one HARQ process has had its HARQ feedback and/or HARQ retransmission disabled. The parameter/IE may not be configured when all the HARQ process have had its HARQ feedback and/or HARQ retransmission enabled. The indication may be configured if the HARQ process has had its HARQ feedback and/or HARQ retransmission enabled/disabled on a per HARQ basis. The indication may be applied for a UL transmission scheduled by a specific UL grant (e.g., DG and/or CG) . The indication may not be applied for a UL transmission scheduled by a specific UL grant (e.g., RAR grant and/or MsgA PUSCH) .

The MAC CE (s) mentioned in the present disclosure may refer to one or more of the following MAC CE (s) :

- C-RNTI MAC CE or data from UL-CCCH

- Configured Grant Confirmation MAC CE or BFR MAC CE or Multiple Entry Configured Grant Confirmation MAC CE

- Sidelink Configured Grant Confirmation MAC CE

- LBT failure MAC CE

- MAC CE for SL-BSR prioritized

- MAC CE for BSR, with exception of BSR included for padding

- Single Entry PHR MAC CE or Multiple Entry PHR MAC CE

- MAC CE for the number of Desired Guard Symbols

- MAC CE for Pre-emptive BSR

- Data from any Logical Channel, except data from UL-CCCH

- MAC CE for Recommended bit rate query

- MAC CE for BSR included for padding

- MAC CE for SL-BSR included for padding

FIG. 10 is a flowchart illustrating a method 1000 performed by a UE for HARQ process operation in an NTN according to an example implementation of the present disclosure. Although

actions

1002, 1004 and 1006 are illustrated as separate actions represented as independent blocks in FIG. 10, these separately illustrated actions should not be construed as necessarily order dependent. The order in which the actions are performed in FIG. 10 is not intended to be construed as a limitation, and any number of the disclosed blocks may be combined in any order to implement the method, or an alternate method. Moreover, each of

actions

1002, 1004 and 1006 may be performed independent of other actions and can be omitted in some implementations of the present disclosure.

In action 1002, the UE may receive a Hybrid Automatic Repeat Request (HARQ) configuration from a Base Station (BS) . The HARQ configuration may indicate a state of a HARQ process. The UE may determine whether disabling HARQ retransmission for the HARQ process based on the state of the HARQ process. In a case that the state of the HARQ process indicates a first value, the UE may enable the HARQ retransmission for the HARQ process. In a case that the state of the HARQ process indicates a second value, the UE may disable the HARQ retransmission for the HARQ process. The UE may determine whether starting a DRX timer for the HARQ process after a UL transmission based on the state of the HARQ process. In a case that the state of the HARQ process indicates a first value, the UE may start the DRX timer for the HARQ process after the UL transmission. In a case that the state of the HARQ process indicates a second value, the UE may not start the DRX timer for the HARQ process after the UL transmission. The HARQ configuration may be configured by a Radio Resource Control (RRC) message. The DRX timer may be a DRX RTT timer (for UL) and/or a DRX retransmission timer (for UL) .

In action 1004, the UE may perform a new transmission using the HARQ process based on an Uplink (UL) grant. The UL grant may be one of a dynamic grant and a configured grant. The configured grant may be a type 1 configured grant and/or a type 2 configured grant.

In action 1006, the UE may select a logical channel for the UL grant based on an indication received from the BS. The indication may indicate whether data from the logical channel can be transmitted using the HARQ process based on the state of the HARQ process. The UE may select the logical channel for the UL grant without considering the indication if the UE is not configured with the HARQ configuration. The indication may be one of a list, a flag, an offset, and a threshold. The indication may be configured by a logical channel configuration.

The method 1000 provided in the present disclosure, when the UE is performing a new transmission using a HARQ process based on a UL grant, the UE can select one or more LCHs for the UL grant based on the configured state of a HARQ process (e.g., based on whether the HARQ process supports the retransmission function) . Therefore, the UE can transmit the data from the LCH (s) via a suitable HARQ process and/or on a suitable UL resource. The benefits are increasing the resource efficiency and scheduling efficiency.

FIG. 11 is a block diagram illustrating a node 1100 for wireless communication according to an example implementation of the present disclosure. As illustrated in FIG. 11, a node 1100 may include a transceiver 1120, a processor 1128, a memory 1134, one or more presentation components 1138, and at least one antenna 1136. The node 1100 may also include a radio frequency (RF) spectrum band module, a BS communications module, a network communications module, and a system communications management module, Input /Output (I/O) ports, I/O components, and a power supply (not illustrated in FIG. 11) .

Each of the components may directly or indirectly communicate with each other over one or more buses 1140. The node 1100 may be a UE or a BS that performs various functions disclosed with reference to FIG. 10.

The transceiver 1120 has a transmitter 1122 (e.g., transmitting/transmission circuitry) and a receiver 1124 (e.g., receiving/reception circuitry) and may be configured to transmit and/or receive time and/or frequency resource partitioning information. The transceiver 1120 may be configured to transmit in different types of subframes and slots including but not limited to usable, non-usable and flexibly usable subframes and slot formats. The transceiver 1120 may be configured to receive data and control channels.

The node 1100 may include a variety of computer-readable media. Computer-readable media may be any available media that may be accessed by the node 1100 and include volatile (and/or non-volatile) media and removable (and/or non-removable) media.

The computer-readable media may include computer-storage media and communication media. Computer-storage media may include both volatile (and/or non-volatile media) , and removable (and/or non-removable) media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or data.

Computer-storage media may include RAM, ROM, EPROM, EEPROM, flash memory (or other memory technology) , CD-ROM, Digital Versatile Disks (DVD) (or other optical disk storage) , magnetic cassettes, magnetic tape, magnetic disk storage (or other magnetic storage devices) , etc. Computer-storage media may not include a propagated data signal. Communication media may typically embody computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanisms and include any information delivery media.

The term “modulated data signal” may mean a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. Communication media may include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the previously listed components should also be included within the scope of computer-readable media.

The memory 1134 may include computer-storage media in the form of volatile and/or non-volatile memory. The memory 1134 may be removable, non-removable, or a combination thereof. Example memory may include solid-state memory, hard drives, optical-disc drives, etc. As illustrated in FIG. 11, the memory 1134 may store a computer-readable and/or computer-executable program 1132 (e.g., software codes) that are configured to, when executed, cause the processor 1128 to perform various functions disclosed herein, for example, with reference to FIG. 10. Alternatively, the program 1132 may not be directly executable by the processor 1128 but may be configured to cause the node 500 (e.g., when compiled and executed) to perform various functions disclosed herein.

The processor 1128 (e.g., having processing circuitry) may include an intelligent hardware device, e.g., a Central Processing Unit (CPU) , a microcontroller, an ASIC, etc. The processor 1128 may include memory. The processor 1128 may process the data 1130 and the program 1132 received from the memory 1134, and information transmitted and received via the transceiver 1120, the base band communications module, and/or the network communications module. The processor 1128 may also process information to send to the transceiver 1120 for transmission via the antenna 1136 to the network communications module for transmission to a CN.

One or more presentation components 1138 may present data indications to a person or another device. Examples of presentation components 1138 may include a display device, a speaker, a printing component, a vibrating component, etc.

In view of the present disclosure, it is obvious that various techniques may be used for implementing the disclosed concepts without departing from the scope of those concepts. Moreover, while the concepts have been disclosed with specific reference to certain implementations, a person of ordinary skill in the art may recognize that changes may be made in form and detail without departing from the scope of those concepts. As such, the disclosed implementations are to be considered in all respects as illustrative and not restrictive. It should also be understood that the present disclosure is not limited to the particular implementations disclosed and many rearrangements, modifications, and substitutions are possible without departing from the scope of the present disclosure.

Claims

A method performed by a User Equipment (UE) , the method comprising:

receiving a Hybrid Automatic Repeat Request (HARQ) configuration from a Base Station (BS) , the HARQ configuration indicating a state of a HARQ process;

performing a new transmission using the HARQ process based on an Uplink (UL) grant; and

selecting a logical channel for the UL grant based on an indication received from the BS, the indication indicating whether data from the logical channel can be transmitted using the HARQ process based on the state of the HARQ process.
The method of claim 1, further comprising:

selecting the logical channel for the UL grant without considering the indication if the UE is not configured with the HARQ configuration.
The method of claim 1, further comprising:

determining whether to disable HARQ retransmission for the HARQ process based on the state of the HARQ process.
The method of claim 3, further comprising:

enabling the HARQ retransmission for the HARQ process in a case that the state of the HARQ process indicates a first value; and

disabling the HARQ retransmission for the HARQ process in a case that the state of the HARQ process indicates a second value.
The method of claim 1, further comprising:

determining whether to start a DRX timer for the HARQ process after a UL transmission based on the state of the HARQ process.
The method of claim 5, further comprising:

starting the DRX timer for the HARQ process after the UL transmission in a case that the state of the HARQ process indicates a first value; and

not starting the DRX timer for the HARQ process after the UL transmission in a case that the state of the HARQ process indicates a second value.
The method of claim 1, wherein the UL grant is one of a dynamic grant and a configured grant.
The method of claim 1, wherein the indication is one of a list, a flag, an offset, and a threshold.
The method of claim 1, wherein the indication is configured by a logical channel configuration.
The method of claim 1, wherein the HARQ configuration is configured by a Radio Resource Control (RRC) message.
A user equipment (UE) , comprising:

one or more non-transitory computer-readable media having computer-executable instructions embodied thereon; and

at least one processor coupled to the one or more non-transitory computer-readable media, the at least one processor configured to execute the computer-executable instructions to:

receive a Hybrid Automatic Repeat Request (HARQ) configuration from a Base Station (BS) , the HARQ configuration indicating a state of a HARQ process;

perform a new transmission using the HARQ process based on an Uplink (UL) grant; and

select a logical channel for the UL grant based on an indication received from the BS, the indication indicating whether data from the logical channel can be transmitted using the HARQ process based on the state of the HARQ process.
The UE of claim 11, wherein the at least one processor is further configured to execute the computer-executable instructions to:

select the logical channel for the UL grant without considering the indication if the UE is not configured with the HARQ configuration.
The UE of claim 11, wherein the at least one processor is further configured to execute the computer-executable instructions to:

determine whether to disable HARQ retransmission for the HARQ process based on the state of the HARQ process.
The UE of claim 13, wherein the at least one processor is further configured to execute the computer-executable instructions to:

enable the HARQ retransmission for the HARQ process in a case that the state of the HARQ process indicates a first value; and

disable the HARQ retransmission for the HARQ process in a case that the state of the HARQ process indicates a second value.
The UE of claim 11, wherein the at least one processor is further configured to execute the computer-executable instructions to:

determine whether to start a DRX timer for the HARQ process after a UL transmission based on the state of the HARQ process.
The UE of claim 15, wherein the at least one processor is further configured to execute the computer-executable instructions to:

start the DRX timer for the HARQ process after the UL transmission in a case that the state of the HARQ process indicates a first value; and

not start the DRX timer for the HARQ process after the UL transmission in a case that the state of the HARQ process indicates a second value.
The UE of claim 11, wherein the UL grant is one of a dynamic grant and a configured grant.
The UE of claim 11, wherein the indication is one of a list, a flag, an offset, and a threshold.
The UE of claim 11, wherein the indication is configured by a logical channel configuration.
The UE of claim 11, wherein the HARQ configuration is configured by a Radio Resource Control (RRC) message.