WO2025048585A1 - Method and apparatus for performing multi-path-based communication in wireless communication system - Google Patents

Abstract

A method and a device for performing communication in a wireless communication system are disclosed. The method performed by a first terminal, according to one embodiment of the present disclosure, comprises the steps of: receiving, from a base station, first configuration information related to a direct path and at least one indirect path; and activating or deactivating the direct path or the at least one indirect path on the basis that at least one measurement value acquired by means of the first terminal satisfies at least one condition, wherein the first configuration information can include first information related to whether activation or deactivation of the direct path or the at least one indirect path is permitted on the basis of the at least one measurement value.

Description

Method and device for performing multipath-based communication in a wireless communication system

The present disclosure relates to a wireless communication system, and more particularly, to a method and device for performing multi-path based communication in a wireless communication system.

Mobile communication systems were developed to provide voice services while ensuring user activity. However, mobile communication systems have expanded their scope to include data services as well as voice, and currently, due to the explosive increase in traffic, resource shortages are occurring and users are demanding higher-speed services, so more advanced mobile communication systems are required.

The requirements for the next generation mobile communication system are that it should be able to accommodate explosive data traffic, dramatically increase the data rate per user, accommodate a greatly increased number of connected devices, support very low end-to-end latency, and support high energy efficiency. To this end, various technologies are being studied, including dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, and device networking.

The technical problem of the present disclosure relates to a method and device for performing multipath-based communication in a wireless communication system.

The technical problem of the present disclosure relates to a method and device for transmitting and receiving data through one or more indirect paths and/or one or more direct paths.

The technical problem of the present disclosure relates to a method and a device for activating or deactivating one or more indirect paths and/or direct paths depending on a measurement result.

The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

In one embodiment of the present disclosure, a method performed by a first terminal in a wireless communication system includes the steps of: receiving, from a base station, first configuration information related to a direct path and at least one indirect path; and activating or deactivating the direct path or the at least one indirect path based on at least one measurement value acquired by the first terminal satisfying at least one condition, wherein the first configuration information may include first information related to whether activation or deactivation of the direct path or the at least one indirect path is permitted based on the at least one measurement value.

In another embodiment of the present disclosure, a method performed by a base station in a wireless communication system includes the steps of: transmitting first configuration information related to a direct path and at least one indirect path to a first terminal; and receiving information about activation or deactivation of the direct path or the at least one indirect path from the first terminal based on at least one measurement value acquired by the first terminal satisfying at least one condition, wherein the first configuration information may include first information related to whether activation or deactivation of the direct path or the at least one indirect path is allowed based on the at least one measurement value.

According to various embodiments of the present disclosure, a method and apparatus for performing multipath-based communication in a wireless communication system can be provided.

According to various embodiments of the present disclosure, methods and devices for transmitting and receiving data via one or more indirect paths and/or one or more direct paths can be provided.

According to various embodiments of the present disclosure, establishment and activation/deactivation of multiple indirect paths can be supported, and various forms of multi-paths can be established/supported depending on the channel environment.

The effects obtainable from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by a person skilled in the art to which the present disclosure belongs from the description below.

The accompanying drawings, which are incorporated in and are incorporated in and are intended to provide an understanding of the present disclosure, illustrate embodiments of the present disclosure and together with the description serve to explain the technical features of the present disclosure.

Figure 1 illustrates the structure of a wireless communication system to which the present disclosure can be applied.

FIG. 2 illustrates a frame structure in a wireless communication system to which the present disclosure can be applied.

FIG. 3 illustrates a resource grid in a wireless communication system to which the present disclosure can be applied.

FIG. 4 illustrates a physical resource block in a wireless communication system to which the present disclosure can be applied.

FIG. 5 illustrates a slot structure in a wireless communication system to which the present disclosure can be applied.

FIG. 6 illustrates physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the same.

FIG. 7 illustrates a procedure for performing V2X or SL communication according to a transmission mode in a wireless communication system to which the present disclosure can be applied.

FIG. 8 illustrates a user plane protocol stack for a U2N (UE-to-network) relay procedure in a wireless communication system to which the present disclosure can be applied.

FIG. 9 illustrates a control plane protocol stack for a U2N relay procedure in a wireless communication system to which the present disclosure can be applied.

FIG. 10 is a diagram for explaining a process in which a first terminal performs communication according to one embodiment of the present disclosure.

FIG. 11 is a diagram for explaining a process in which a base station performs communication according to one embodiment of the present disclosure.

FIG. 12 is a diagram for explaining a multi-path scenario according to one embodiment of the present disclosure.

FIG. 13 is a diagram for explaining the configuration of a MAC CE according to one embodiment of the present disclosure.

FIG. 14 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below together with the accompanying drawings is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

In some cases, to avoid obscuring the concepts of the present disclosure, well-known structures and devices may be omitted or illustrated in block diagram format focusing on the core functions of each structure and device.

In the present disclosure, when a component is said to be "connected", "coupled" or "connected" to another component, this may include not only a direct connection relationship, but also an indirect connection relationship in which another component exists between them. Also, the terms "comprises" or "has" in the present disclosure specify the presence of the mentioned features, steps, operations, elements and/or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and/or groups thereof.

In this disclosure, the terms “first,” “second,” etc. are used only to distinguish one component from other components and are not used to limit the components, and do not limit the order or importance among the components unless specifically stated otherwise. Accordingly, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The term "and/or" as used herein may refer to any one of the associated enumerated items or is meant to refer to and encompass any and all possible combinations of two or more of them. Furthermore, the word "/" used between words in this disclosure has the same meaning as "and/or" unless otherwise stated.

The present disclosure describes a wireless communication network or a wireless communication system, and an operation performed in a wireless communication network may be performed in a process of controlling the network and transmitting or receiving a signal from a device (e.g., a base station) that manages the wireless communication network, or in a process of transmitting or receiving a signal with or between terminals connected to the wireless network.

In the present disclosure, transmitting or receiving a channel means transmitting or receiving information or a signal through the channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal through the data channel.

Hereinafter, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In the downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In the uplink, a transmitter may be part of a terminal, and a receiver may be part of a base station. The base station may be expressed as a first communication device, and the terminal may be expressed as a second communication device. A base station (BS) may be replaced by terms such as a fixed station, a Node B, an evolved-NodeB (eNB), a Next Generation NodeB (gNB), a base transceiver system (BTS), an Access Point (AP), a network (5G network), an Artificial Intelligence (AI) system/module, a road side unit (RSU), a robot, a drone (UAV: Unmanned Aerial Vehicle), an Augmented Reality (AR) device, and a Virtual Reality (VR) device. In addition, the terminal may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, RSU (road side unit), robot, AI (Artificial Intelligence) module, UAV (Unmanned Aerial Vehicle), AR (Augmented Reality) device, and VR (Virtual Reality) device.

The technology below can be used in various wireless access systems, such as CDMA, FDMA, TDMA, OFDMA, and SC-FDMA. CDMA can be implemented with wireless technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (Global System for Mobile communications)/GPRS (General Packet Radio Service)/EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented with wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (Evolved UTRA). UTRA is a part of UMTS (Universal Mobile Telecommunications System). 3GPP(3rd Generation Partnership Project) LTE(Long Term Evolution) is a part of E-UMTS(Evolved UMTS) that uses E-UTRA, and LTE-A(Advanced)/LTE-A pro is an evolved version of 3GPP LTE. 3GPP NR(New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE/LTE-A/LTE-A pro.

For the sake of clarity, the description is based on a 3GPP communication system (e.g., LTE-A, NR), but the technical idea of the present disclosure is not limited thereto. LTE refers to technology after 3GPP TS (Technical Specification) 36.xxx Release 8. Specifically, LTE technology after 3GPP TS 36.xxx Release 10 is referred to as LTE-A, and LTE technology after 3GPP TS 36.xxx Release 13 is referred to as LTE-A pro. 3GPP NR refers to technology after TS 38.xxx Release 15. LTE/NR may be referred to as a 3GPP system. “xxx” refers to a standard document detail number. LTE/NR may be collectively referred to as a 3GPP system. With respect to background technologies, terms, abbreviations, etc. used in the description of the present disclosure, reference may be made to matters described in standard documents published prior to the present disclosure. For example, reference may be made to the following documents:

For 3GPP LTE, see TS 36.211 (Physical channels and modulation), TS 36.212 (Multiplexing and channel coding), TS 36.213 (Physical layer procedures), TS 36.300 (General description), and TS 36.331 (Radio resource control).

For 3GPP NR, see TS 38.211 (Physical channels and modulation), TS 38.212 (Multiplexing and channel coding), TS 38.213 (Physical layer procedures for control), TS 38.214 (Physical layer procedures for data), TS 38.300 (Overall description of NR and New Generation-Radio Access Network (NG-RAN)), and TS 38.331 (Radio Resource Control protocol specification).

The abbreviations of terms that may be used in this disclosure are defined as follows.

- BM: beam management

- CQI: channel quality indicator

- CRI: Channel state information - reference signal resource indicator

- CSI: channel state information

- CSI-IM: Channel state information - interference measurement

- CSI-RS: Channel state information - reference signal

- DMRS: Demodulation reference signal

- FDM: Frequency division multiplexing

- FFT: fast Fourier transform

- IFDMA: interleaved frequency division multiple access

- IFFT: inverse fast Fourier transform

- L1-RSRP: Layer 1 reference signal received power

- L1-RSRQ: Layer 1 reference signal received quality

- MAC: Medium Access Control

- NZP: non-zero power

- OFDM: Orthogonal frequency division multiplexing

- PDCCH: physical downlink control channel

- PDSCH: physical downlink shared channel

- PMI: precoding matrix indicator

- RE: resource element

- RI: Rank indicator

- RRC: radio resource control

- RSSI: received signal strength indicator

- Rx: Reception

- QCL: quasi co-location

- SINR: signal to interference and noise ratio

- SSB (or SS/PBCH block): Synchronization signal block (including primary synchronization signal (PSS), secondary synchronization signal (SSS), and physical broadcast channel (PBCH))

- TDM: time division multiplexing

- TRP: transmission and reception point

- TRS: Tracking reference signal

- Tx: transmission

- UE: user equipment

- ZP: zero power

System General

As more and more communication devices require greater communication capacity, there is a growing need for improved mobile broadband communication over existing radio access technology (RAT). In addition, massive MTC (machine type communications), which connects a large number of devices and objects to provide various services anytime and anywhere, is also one of the major issues to be considered in next-generation communications. In addition, a communication system design that considers services/terminals that are sensitive to reliability and latency is being discussed. The introduction of next-generation RATs that consider eMBB (enhanced mobile broadband communication), Mmtc (massive MTC), URLLC (utra-reliable and low latency communication), etc. is being discussed, and in this disclosure, the technology is referred to as NR for convenience. NR is an expression indicating an example of 5G RAT.

The new RAT system including NR uses OFDM transmission scheme or similar transmission scheme. The new RAT system may follow OFDM parameters different from those of LTE. Or, the new RAT system may follow the existing LTE/LTE-A numerology but support a larger system bandwidth (e.g., 100MHz). Or, a single cell may support multiple numerologies. That is, terminals operating with different numerologies may coexist in a single cell.

A numerology corresponds to one subcarrier spacing in the frequency domain. Different numerologies can be defined by scaling the reference subcarrier spacing by an integer N.

Figure 1 illustrates the structure of a wireless communication system to which the present disclosure can be applied.

Referring to Fig. 1, the NG-RAN consists of gNBs providing NG-RA (NG-Radio Access) user plane (i.e., new AS (access stratum) sublayer/PDCP (packet data convergence protocol)/RLC (radio link control)/MAC/PHY) and control plane (RRC) protocol termination for UE. The gNBs are interconnected via Xn interface. The gNBs are also connected to NGC (New Generation Core) via NG interface. More specifically, the gNBs are connected to AMF (Access and Mobility Management Function) via N2 interface and to UPF (User Plane Function) via N3 interface.

FIG. 2 illustrates a frame structure in a wireless communication system to which the present disclosure can be applied.

NR system can support multiple numerologies, where the numerology can be defined by subcarrier spacing and cyclic prefix (CP) overhead. Here, multiple subcarrier spacings can be derived by scaling the base (reference) subcarrier spacing by an integer N (or μ). Also, even if it is assumed that very low subcarrier spacing is not used at very high carrier frequencies, the numerology used can be selected independently of the frequency band. Also, NR system can support various frame structures according to multiple numerologies.

Below, we examine OFDM numerologies and frame structures that can be considered in NR systems. A number of OFDM numerologies supported in NR systems can be defined as shown in Table 1 below.

μ Δf=2 ^μ ·15 [kHz] CP 0 15 Normal 1 30 common 2 60 General, Extended 3 120 common 4 240 common

NR supports multiple numerologies (or subcarrier spacing (SCS)) to support various 5G services. For example, when the SCS is 15 kHz, it supports a wide area in traditional cellular bands, when the SCS is 30 kHz/60 kHz, it supports dense-urban, lower latency, and wider carrier bandwidth, and when the SCS is 60 kHz or higher, it supports a bandwidth larger than 24.25 GHz to overcome phase noise. The NR frequency band is defined by two types of frequency ranges (FR1, FR2). FR1 and FR2 can be configured as shown in Table 2 below. In addition, FR2 can mean millimeter wave (mmW).

Frequency Range designation Corresponding frequency range Subcarrier Spacing FR1 410MHz - 7125MHz 15, 30, 60kHz FR2 24250MHz - 52600MHz 60, 120, 240kHz

With respect to the frame structure in an NR system, the sizes of various fields in the time domain are expressed in multiples of a time unit of T _c = 1/(Δf _max ·N _f ). Here, Δf _max = 480 · 10 ³ Hz and N _f = 4096. Downlink and uplink transmissions are organized into radio frames having a duration of T _f = 1/(Δf _max N _f /100) · T _c = 10 ms. Here, the radio frame consists of 10 subframes, each having a duration of T _sf = (Δf _max N _f /1000) · T _c = 1 ms. In this case, there can be one set of frames for uplink and one set of frames for downlink. In addition, transmission in uplink frame number i from a terminal must start before the start of the corresponding downlink frame at the terminal T _TA =(N _TA +N _TA,offset )T _c . For a subcarrier spacing configuration μ , slots are numbered in increasing order of n _s ^μ ∈{0,..., N _slot ^subframe,μ -1} within a subframe, and in increasing order of n _s,f ^μ ∈{0,..., N _slot ^frame,μ -1} within a radio frame. One slot consists of consecutive OFDM symbols of N _symb ^slot , where N _symb ^slot is determined according to a CP. The start of slot n _s ^μ in a subframe is temporally aligned with the start of OFDM symbol n _s ^μ N _symb ^slot in the same subframe. Not all terminals can transmit and receive simultaneously, which means that not all OFDM symbols in a downlink slot or uplink slot can be utilized.

Table 3 shows the number of OFDM symbols per slot (N _symb ^slot ), the number of slots per radio frame (N _slot ^frame,μ ), and the number of slots per subframe (N _slot ^subframe,μ ) in the general CP, and Table 4 shows the number of OFDM symbols per slot, the number of slots per radio frame, and the number of slots per subframe in the extended CP.

μ N _symb ^slot N _slot ^frame,μ N _slot ^subframe,μ 0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

μ N _symb ^slot N _slot ^frame,μ N _slot ^subframe,μ 2 12 40 4

FIG. 2 is an example when μ=2 (SCS is 60 kHz), and referring to Table 3, 1 subframe can include 4 slots. 1 subframe={1,2,4} slot illustrated in FIG. 2 is an example, and the number of slot(s) that can be included in 1 subframe is defined as in Table 3 or Table 4. In addition, a mini-slot can include 2, 4, or 7 symbols, or more or fewer symbols. With respect to physical resources in an NR system, an antenna port, a resource grid, a resource element, a resource block, a carrier part, etc. can be considered.

Hereinafter, the physical resources that can be considered in the NR system will be specifically described. First, with respect to an antenna port, an antenna port is defined such that a channel on which a symbol on the antenna port is carried can be inferred from a channel on which another symbol on the same antenna port is carried. If a large-scale property of a channel on which a symbol on one antenna port is carried can be inferred from a channel on which a symbol on another antenna port is carried, the two antenna ports can be said to be in a QC/QCL (quasi co-located or quasi co-location) relationship. Here, the large-scale property includes one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing. FIG. 3 illustrates a resource grid in a wireless communication system to which the present disclosure can be applied. Referring to FIG. 3, a resource grid is exemplarily described as consisting of N _RB ^μ N _sc ^RB subcarriers in the frequency domain and one subframe consisting of 14·2 ^μ OFDM symbols, but is not limited thereto. In an NR system, a transmitted signal is described by one or more resource grids consisting of N _RB ^μ N _sc ^RB subcarriers and OFDM symbols of 2 ^μ N _symb ^(μ) . Here, N _RB ^μ ≤ _{N RB} ^max,μ . The N _RB ^max,μ represents a maximum transmission bandwidth, which may vary between uplink and downlink as well as numerologies. In this case, one resource grid may be configured for μ and each antenna port p. Each element of the resource grid for μ and each antenna port p is referred to as a resource element and is uniquely identified by an index pair (k,l').

Here, k=0,...,N _RB ^μ N _sc ^RB -1 is an index on the frequency domain, and l'=0,...,2 ^μ N _symb ^(μ) -1 designates the position of a symbol within a subframe. When designating a resource element in a slot, an index pair (k,l) is used. Here, l=0,...,N _symb ^μ -1. The resource element (k,l') for μ and antenna port p corresponds to a complex value a _k,l' ^(p,μ) . If there is no risk of confusion or if a particular antenna port or numerology is not specified, the indices p and μ can be dropped, resulting in a complex value a _k,l' ^(p) or a _k,l' . Furthermore, a resource block (RB) is defined as N _sc ^RB =12 consecutive subcarriers on the frequency domain.

Point A serves as a common reference point of the resource block grid and is obtained as follows.

- offsetToPointA for Primary Cell (PCell) downlink indicates the frequency offset between point A and the lowest subcarrier of the lowest resource block overlapping with the SS/PBCH block used by the UE for initial cell selection. It is expressed in resource block units assuming 15 kHz subcarrier spacing for FR1 and 60 kHz subcarrier spacing for FR2.

- absoluteFrequencyPointA represents the frequency-position of point A expressed as ARFCN (absolute radio-frequency channel number).

Common resource blocks (CRBs) are numbered from 0 upward in the frequency domain for the subcarrier spacing setting μ. The center of subcarrier 0 of common resource block 0 for the subcarrier spacing setting μ coincides with 'point A'. The relationship between common resource block number n _CRB ^μ in the frequency domain and resource elements (k, l) for the subcarrier spacing setting μ is given by the following mathematical expression 1.

In Equation 1, k is defined relative to point A such that k = 0 corresponds to the subcarrier centered at point A. The physical resource blocks are numbered from 0 to N _BWP,i ^size,μ -1 within a bandwidth part (BWP), where i is the number of the BWP. The relationship between a physical resource block n _PRB and a common resource block n _CRB in a BWP i is given by Equation 2 below.

N _BWP,i ^start,μ is the common resource block where the BWP starts relative to common resource block 0.

FIG. 4 illustrates a physical resource block in a wireless communication system to which the present disclosure can be applied. FIG. 5 illustrates a slot structure in a wireless communication system to which the present disclosure can be applied.

Referring to FIGS. 4 and 5, a slot includes multiple symbols in the time domain. For example, in the case of normal CP, one slot includes 7 symbols, but in the case of extended CP, one slot includes 6 symbols.

A carrier includes multiple subcarriers in the frequency domain. An RB (Resource Block) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) is defined as multiple consecutive (physical) resource blocks in the frequency domain, and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for one terminal. Each element in the resource grid is referred to as a Resource Element (RE), and one complex symbol can be mapped.

The NR system can support up to 400 MHz per component carrier (CC). If a terminal operating in such a wideband CC always operates with the radio frequency (RF) chip for the entire CC turned on, the terminal battery consumption may increase. Or, when considering multiple use cases (e.g., eMBB, URLLC, Mmtc, V2X, etc.) operating in a single wideband CC, different numerologies (e.g., subcarrier spacing, etc.) may be supported for each frequency band within the CC. Or, the capability for maximum bandwidth may be different for each terminal. Considering this, the base station may instruct the terminal to operate only in a part of the bandwidth rather than the entire bandwidth of the wideband CC, and the part of the bandwidth is conveniently defined as the bandwidth part (BWP). A BWP can be composed of consecutive RBs on the frequency axis and can correspond to one numerology (e.g., subcarrier spacing, CP length, slot/mini-slot interval).

Meanwhile, the base station can set multiple BWPs even within one CC set for the terminal. For example, in the PDCCH monitoring slot, a BWP that occupies a relatively small frequency domain can be set, and the PDSCH indicated by the PDCCH can be scheduled on a larger BWP.

Alternatively, when UEs are concentrated in a specific BWP, some terminals can be set to a different BWP for load balancing. Alternatively, considering frequency domain inter-cell interference cancellation between neighboring cells, some spectrum in the middle of the entire bandwidth can be excluded and both BWPs can be set within the same slot. That is, the base station can set at least one DL/UL BWP for a terminal associated with a wideband CC.

The base station can activate (by L1 signaling or MAC CE (Control Element) or RRC signaling, etc.) at least one DL/UL BWP among the DL/UL BWP(s) configured at a specific point in time. In addition, the base station can instruct switching to another configured DL/UL BWP (by L1 signaling or MAC CE or RRC signaling, etc.). Or, switching to a determined DL/UL BWP may be performed when a timer value expires based on a timer. In this case, the activated DL/UL BWP is defined as an active DL/UL BWP. However, since the UE may not receive the configuration for the DL/UL BWP when the UE is performing an initial access procedure or before the RRC connection is set up, the DL/UL BWP assumed by the UE in such a situation is defined as an initially active DL/UL BWP.

FIG. 6 illustrates physical channels used in a wireless communication system to which the present disclosure can be applied and a general signal transmission and reception method using the same.

In a wireless communication system, a terminal receives information from a base station through a downlink, and the terminal transmits information to the base station through an uplink. The information transmitted and received by the base station and the terminal includes data and various control information, and various physical channels exist depending on the type/purpose of the information they transmit and receive.

When the terminal is powered on or enters a new cell, it performs an initial cell search operation such as synchronizing with the base station (S601). To this end, the terminal can receive a primary synchronization signal (PSS) and a secondary synchronization signal (PSS) from the base station to synchronize with the base station and obtain information such as a cell identifier (ID). Thereafter, the terminal can receive a physical broadcast channel (PBCH) from the base station to obtain broadcast information within the cell. Meanwhile, the terminal can receive a downlink reference signal (DL RS) in the initial cell search phase to check the downlink channel status.

A terminal that has completed an initial cell search can obtain more specific system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information carried on the PDCCH (S602).

Meanwhile, when accessing a base station for the first time or when there is no radio resource for signal transmission, the terminal may perform a random access procedure (RACH) for the base station (steps S603 to S606). To this end, the terminal may transmit a specific sequence as a preamble through a random access channel (RACH) (S603 and S605), and receive a response message to the preamble through a PDCCH and a corresponding PDSCH (S604 and S606). In case of a collision-based RACH, a contention resolution procedure may additionally be performed.

The terminal that has performed the procedure as described above can then perform PDCCH/PDSCH reception (S607) and physical uplink shared channel (PUSCH)/physical uplink control channel (PUCCH) transmission (S608) as general uplink/downlink signal transmission procedures. In particular, the terminal receives downlink control information (DCI) through the PDCCH. Here, the DCI includes control information such as resource allocation information for the terminal, and its format is different depending on the purpose of use.

Meanwhile, the control information that the terminal transmits to the base station via uplink or that the terminal receives from the base station includes downlink/uplink ACK/NACK (Acknowledgement/Non-Acknowledgement) signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Indicator), RI (Rank Indicator), etc. In the case of the 3GPP LTE system, the terminal can transmit the above-described control information such as CQI/PMI/RI via PUSCH and/or PUCCH.

Table 5 shows an example of DCI format in the NR system.

DCI format conjugation 0_0 Scheduling of PUSCH within a cell 0_1 Scheduling of one or multiple PUSCHs within a cell, or indicating cell group (CG) downlink feedback information to the UE. 0_2 Scheduling of PUSCH within a cell 1_0 Scheduling of PDSCH within a DL cell 1_1 Scheduling of PDSCH within a cell 1_2 Scheduling of PDSCH within a cell

Referring to Table 5, DCI formats 0_0, 0_1, and 0_2 may include resource information related to PUSCH scheduling (e.g., UL/SUL (Supplementary UL), frequency resource allocation, time resource allocation, frequency hopping, etc.), transport block (TB) related information (e.g., MCS (Modulation Coding and Scheme), NDI (New Data Indicator), RV (Redundancy Version), etc.), HARQ (Hybrid - Automatic Repeat and request) related information (e.g., process number, DAI (Downlink Assignment Index), PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., DMRS sequence initialization information, antenna port, CSI request, etc.), power control information (e.g., PUSCH power control, etc.), and the control information included in each DCI format may be predefined.

DCI format 0_0 is used for scheduling PUSCH in a cell. Information included in DCI format 0_0 is transmitted with CRC (cyclic redundancy check) scrambled by C-RNTI (cell radio network temporary identifier, Cell RNTI) or CS-RNTI (Configured Scheduling RNTI) or MCS-C-RNTI (Modulation Coding Scheme Cell RNTI).

DCI format 0_1 is used to indicate scheduling of one or more PUSCHs in a cell, or configure grant (CG) downlink feedback information to the UE. The information included in DCI format 0_1 is transmitted by CRC scrambled by C-RNTI or CS-RNTI or SP-CSI-RNTI (Semi-Persistent CSI RNTI) or MCS-C-RNTI.

DCI format 0_2 is used for scheduling PUSCH in a cell. Information included in DCI format 0_2 is transmitted by CRC scrambled by C-RNTI or CS-RNTI or SP-CSI-RNTI or MCS-C-RNTI.

Next, DCI formats 1_0, 1_1, and 1_2 may include resource information related to scheduling of PDSCH (e.g., frequency resource allocation, time resource allocation, virtual resource block (VRB)-physical resource block (PRB) mapping, etc.), transport block (TB) related information (e.g., MCS, NDI, RV, etc.), HARQ related information (e.g., process number, DAI, PDSCH-HARQ feedback timing, etc.), multi-antenna related information (e.g., antenna port, transmission configuration indicator (TCI), sounding reference signal (SRS) request, etc.), PUCCH related information (e.g., PUCCH power control, PUCCH resource indicator, etc.), and control information included in each DCI format may be predefined.

DCI format 1_0 is used for scheduling PDSCH in one DL cell. Information included in DCI format 1_0 is transmitted CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI.

DCI format 1_1 is used for scheduling PDSCH in one cell. Information included in DCI format 1_1 is transmitted by CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI.

DCI format 1_2 is used for scheduling PDSCH in a cell. Information included in DCI format 1_2 is transmitted by CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI.

V2X (vehicle-to-everything)/side link (SL: sidelink) communication

FIG. 7 illustrates a procedure for performing V2X or SL communication according to a transmission mode in a wireless communication system to which the present disclosure can be applied.

The embodiment of FIG. 7 can be combined with various embodiments of the present disclosure. In various embodiments of the present disclosure, the transmission mode can be referred to as a mode or a resource allocation mode. Hereinafter, for convenience of explanation, the transmission mode in LTE can be referred to as an LTE transmission mode, and the transmission mode in NR can be referred to as an NR resource allocation mode.

For example, Fig. 7(a) illustrates the operation of a UE related to LTE transmission mode 1 or LTE transmission mode 3. Or, for example, Fig. 7(a) illustrates the operation of a UE related to NR resource allocation mode 1. For example, LTE transmission mode 1 can be applied to general SL communication, and LTE transmission mode 3 can be applied to V2X communication.

For example, Fig. 7(b) illustrates the operation of a UE associated with LTE transmission mode 2 or LTE transmission mode 4. Or, for example, Fig. 7(b) illustrates the operation of a UE associated with NR resource allocation mode 2.

Referring to Fig. 7(a), in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the base station can schedule SL resources to be used by the UE for SL transmission (S8000). For example, the base station can transmit information related to SL resources and/or information related to UL resources to the first UE. For example, the UL resources can include PUCCH resources and/or PUSCH resources. For example, the UL resources can be resources for reporting SL HARQ feedback to the base station.

For example, the first UE may receive information related to a dynamic grant (DG) resource and/or information related to a configured grant (CG) resource from the base station. For example, the CG resource may include a CG type 1 resource or a CG type 2 resource. In the present disclosure, the DG resource may be a resource that the base station configures/allocates to the first UE via DCI. In the present disclosure, the CG resource may be a (periodic) resource that the base station configures/allocates to the first UE via DCI and/or an RRC message. For example, in the case of a CG type 1 resource, the base station may transmit an RRC message including information related to the CG resource to the first UE. For example, in the case of a CG type 2 resource, the base station may transmit an RRC message including information related to the CG resource to the first UE, and the base station may transmit DCI related to activation or release of the CG resource to the first UE.

The first UE may transmit PSCCH (e.g., Sidelink Control Information (SCI) or 1st-stage SCI) to the second UE based on the resource scheduling (S8010).

The first UE can transmit a PSSCH (e.g., a 2nd-stage SCI, a MAC protocol data unit (PDU), data, etc.) related to the PSCCH to the second UE (S8020).

The first UE can receive a PSFCH related to the PSCCH/PSSCH from the second UE (S8030). For example, HARQ feedback information (e.g., NACK information or ACK information) can be received from the second UE via the PSFCH.

The first UE can transmit/report HARQ feedback information to the base station via PUCCH or PUSCH (S8040). For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on HARQ feedback information received from the second UE. For example, the HARQ feedback information reported to the base station may be information generated by the first UE based on a rule set in advance. For example, the DCI may be DCI for scheduling of SL. For example, the format of the DCI may be DCI format 3_0 or DCI format 3_1.

Referring to FIG. 7(b), in LTE transmission mode 2, LTE transmission mode 4 or NR resource allocation mode 2, the UE can determine SL transmission resources within SL resources configured by a base station/network or preset SL resources. For example, the configured SL resources or preset SL resources may be a resource pool. For example, the UE can autonomously select or schedule resources for SL transmission. For example, the UE can perform SL communication by selecting resources by itself within the configured resource pool. For example, the UE can perform sensing and resource (re)selection procedures to select resources by itself within a selection window. For example, the sensing may be performed on a sub-channel basis.

A first UE that has selected a resource within a resource pool can transmit a PSCCH (e.g., SCI or 1st-stage SCI) to a second UE using the resource (S8010).

The first UE can transmit a PSSCH (e.g., 2nd-stage SCI, MAC PDU, data, etc.) related to the PSCCH to the second UE (S8020).

The first UE can receive a PSFCH related to the PSCCH/PSSCH from the second UE (S8030).

Referring to FIG. 7(a) or FIG. 7(b), for example, a first UE may transmit an SCI to a second UE on a PSCCH. Or, for example, the first UE may transmit two consecutive SCIs (e.g., 2-stage SCIs) to the second UE on the PSCCH and/or the PSSCH. In this case, the second UE may decode the two consecutive SCIs (e.g., 2-stage SCIs) to receive the PSSCH from the first UE. In the present disclosure, the SCI transmitted on the PSCCH may be referred to as a first (1st) SCI, a first SCI, a first-stage SCI, or a 1st-stage SCI format, and the SCI transmitted on the PSSCH may be referred to as a second (2 ^nd ) SCI, a second SCI, a second-stage (2nd-stage) SCI, or a 2nd-stage SCI format. For example, a 1st-stage SCI format may include SCI format 1-A, and a 2nd-stage SCI format may include SCI format 2-A and/or SCI format 2-B.

Referring to FIG. 7(a) or FIG. 7(b), in step S8030, the first UE may receive a PSFCH based on the description to be described below. For example, the first UE and the second UE may determine a PSFCH resource based on the description to be described below, and the second UE may transmit HARQ feedback to the first UE using the PSFCH resource.

SL Relay Procedure

The SL Relay procedure is introduced to support 5G ProSe U2N relay functionality to provide network connectivity for U2N (UE-to-network) remote terminals. That is, both L2 and L3 U2N relay architectures can be supported.

A U2N relay terminal may be in RRC_CONNECTED state to perform relaying of unicast data. For L2 U2N relay operation, the following RRC state combinations may be supported:

- Both the U2N relay terminal and the U2N remote terminal must be in the RRC_CONNECTED state to transmit/receive relayed unicast data.

- If all U2N remote terminals connected to the U2N relay terminal are in RRC_INACTIVE or RRC_IDLE state, the U2N relay terminal can be in RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state.

For L2 U2N relay procedures, the U2N remote terminal may be configured to use only resource allocation mode 2 for data to be relayed.

A single unicast link can be established between a L2 U2N relay terminal and a L2 U2N remote terminal. The traffic of a U2N remote terminal through a specific U2N relay terminal and the traffic of the U2N relay terminal must be separated into different Uu RLC channels through Uu.

When the U2N relay function is set for a relay terminal and a remote terminal, the relay terminal can provide network connection to the U2N remote terminal(s). In this case, the remote terminal may not have a direct connection to the network while maintaining an indirect connection based on the U2N relay function.

The protocol stacks for the user plane and the control plane of the L2 U2N relay architecture can be configured as shown in FIG. 8 and FIG. 9, respectively. The sidelink relay adaptation protocol (SRAP) sublayer can be placed above the RLC sublayer for both the control plane (CP) and the user plane (UP) on both the PC5 interface and the Uu interface. Between the L2 U2N remote terminal and the base station, the Uu SDAP (service data adaptation protocol), PDCP (packet data convergence protocol), and RRC are terminated, and at each hop (i.e., the link between the L2 U2N remote terminal and the L2 U2N relay terminal, and the link between the L2 U2N relay terminal and the base station), SRAP, RLC, MAC, and PHY can be terminated.

For L2 U2N relay, SRAP sublayer over PC5 hop can be used only for bearer mapping purpose. SRAP sublayer for relaying messages of L2 U2N remote terminal over BCCH and PCCH may not exist over PC5 hop. For L2 U2N remote terminal messages on signaling radio bearer (SRB)0, SRAP sublayer does not exist over PC5 hop, but SRAP sublayer may exist over Uu hop for both DL and UL. Here, SRB0 can be used for transmission of RRC messages associated with common control channel (CCCH) logical channel.

As an example of the present disclosure, in the uplink in a L2 U2N relay procedure, the Uu SRAP sublayer can support UL bearer mapping between a receiving PC5 relay RLC channel and a transmitting Uu relay RLC channel for relaying over a L2 U2N relay terminal Uu interface. For uplink relay traffic, different end-to-end RBs (e.g., SRBs or data radio bearers (DRBs)) of the same remote terminal and/or different remote terminals can be multiplexed over the same Uu relay RLC channel. Here, the Uu SRAP sublayer can support L2 U2N remote terminal identification for UL traffic.

The identification information of the L2 U2N remote terminal Uu radio bearer and the local remote terminal ID may be included in the Uu SRAP header in UL for the base station to correlate received packets for a particular PDCP entity associated with the correct Uu radio bearer of the remote terminal. The PC5 SRAP sublayer of the L2 U2N remote terminal may support UL bearer mapping between the remote terminal Uu radio bearer and the egress PC5 relay RLC channel.

As an example of the present disclosure, in the downlink in the L2 U2N relay procedure, the Uu SRAP lower layer can support DL bearer mapping at the base station to map SRBs, DRBs (i.e., end-to-end radio bearers) of remote terminals to Uu relay RLC channels via the relay terminal Uu interface.

The Uu SRAP sublayer may support DL bearer mapping and data multiplexing between multiple end-to-end radio bearers (i.e., SRBs or DRBs) of L2 U2N remote terminals and/or between one Uu relay RLC channel over a relay terminal Uu interface.

The Uu SRAP sublayer may support remote UE identification for DL traffic. In order to map packets received from the relay terminal and the remote terminal Uu radio bearer to the relevant PC5 relay RLC channel, the identification information of the remote terminal Uu radio bearer and the local remote terminal ID may be included in the Uu SRAP header by the base station in the DL. The PC5 SRAP sublayer of the relay terminal may support DL bearer mapping between the ingress Uu relay RLC channel and the egress PC5 relay RLC channel.

The PC5 SRAP sublayer of the remote terminal can correlate the received packet to a specific PDCP entity associated with the correct Uu radio bearer of the remote terminal based on the identification information contained in the Uu SRAP header.

The local remote terminal ID can be included in both the PC5 SRAP header and the Uu SRAP header. The L2 U2N relay terminal can be configured by the base station with a local remote terminal ID to be used in the SRAP header. The remote terminal can obtain the local remote ID from the base station via Uu RRC messages including RRCSetup, RRCReconfiguration, RRCResume and RRCRefoundment. Uu DRB(s) and Uu SRB(s) can be mapped to different PC5 relay RLC channels and Uu relay RLC channels in both PC5 hop and Uu hop.

It is the responsibility of the base station to avoid collisions when using local remote terminal IDs. The base station can update the local remote terminal ID by sending the updated local remote ID to the relay terminal via the RRCReconfiguration message. The serving base station can perform the local remote terminal ID update independently of the PC5 unicast link L2 ID update procedure.

Multi-path based communication operation

In a basic wireless communication system, when the U2N relay function is set for a relay terminal and a remote terminal, the relay terminal can provide a network connection to the U2N remote terminal(s). At this time, the remote terminal may not have a direct connection with the network while maintaining an indirect connection based on the U2N relay function.

It may be advantageous for a remote terminal to support multi-path operation by maintaining direct connections only to Uu, as well as indirect connections based on PC5 and Uu. For more reliable transmission and/or higher throughput, a remote terminal configured for multi-path operation may select at least one of the multiple connections for data transmission toward the network.

In a basic wireless communication system, a remote terminal must maintain both paths regardless of which path is used for actual data transmission, which may require a large amount of power consumption and terminal complexity. In an improved wireless communication system, for multipath operation, a remote terminal can establish an indirect path and a direct path.

For example, if a relay terminal is available on the vehicle while the remote terminal is in a moving or flying vehicle, the remote terminal on the vehicle does not need to maintain both paths (i.e., the indirect path and the direct path).

Below, we describe operations related to direct paths and indirect paths for multipath operation in a wireless communication system.

FIG. 10 is a diagram for explaining a process in which a first terminal performs communication according to one embodiment of the present disclosure. In FIG. 10 and FIG. 11, the first terminal may be a remote terminal and the second terminal may be a relay terminal. However, this is only one embodiment, and the first terminal may be a relay terminal and the second terminal may be a remote terminal.

A first terminal (e.g., a remote terminal) can perform a communication connection with a base station via a second terminal (e.g., a relay terminal) using an indirect path. In other words, an indirect path can be a general term for a path between a remote terminal and a base station that passes through a relay terminal.

And, the second terminal (or remote terminal) can be replaced with a relay node or/and a satellite node, etc. In addition, the first terminal and the second terminal can be connected with a side link, a N3C (non-3GPP connection) (e.g., Wi-Fi, Bluetooth, etc.), a NTN (non-terrestrial network)-based connection, etc. In addition, the base station can be replaced with a TN (terrestrial network) node or/and a NTN-based satellite node.

The first terminal can receive first configuration information related to a direct path and at least one indirect path from the base station (S1010).

As an example of the present disclosure, the terminal may receive first configuration information from the base station via upper layer signaling (e.g., RRC message and/or SIB, etc.). A direct path and at least one indirect path may be established for the terminal by the first configuration information.

For example, the first configuration information may include first information related to whether activation or deactivation of a direct path or at least one indirect path is permitted based on at least one measurement value acquired by the first terminal.

That is, the first information may include information on whether the first terminal is allowed to activate/deactivate the direct/indirect path using the measurement value measured/acquired by the first terminal. The base station may set, through the first information, whether to allow the first terminal to autonomously activate/deactivate the direct/indirect path.

However, this is only an example, and the first information may not be included in the first configuration information. That is, the terminal may receive the first information from the base station through separate configuration information. For example, the first information may be included in the second configuration information, and the second configuration information may be transmitted and received through upper layer signaling separate from the first configuration information.

In FIG. 10 and FIG. 11, it is assumed that autonomous direct/indirect path activation/deactivation of the first terminal based on the measurement value measured/acquired by the first terminal is permitted by the first information. If autonomous direct/indirect path activation/deactivation of the first terminal is not permitted, the terminal can activate/deactivate the direct/indirect path according to the control information received from the base station.

Additionally or alternatively, the first configuration information may include second information related to whether the direct path and the at least one indirect path are initially activated. That is, the second information may indicate/set whether only the direct path is initially activated, only the at least one indirect path is activated, or both the direct path and the at least one indirect path are activated. Of the direct path and the at least one indirect path, the remaining paths except those indicated/set to be initially activated by the second information may be deactivated.

Based on at least one measurement value acquired by the first terminal satisfying at least one condition, the first terminal can activate or deactivate a direct path or at least one indirect path (S1020).

As an example of the present disclosure, at least one measurement value acquired by the first terminal may include at least one of an altitude of the first terminal, a velocity of the first terminal, a cell quality value of a direct path, or a quality value associated with at least one indirect path (e.g., an SL quality value, etc.).

And, at least one condition may include at least one of a first condition related to whether an altitude of the first terminal is equal to or greater than (or greater than) or less than (or less than) a first threshold value, a second condition related to whether a speed of the first terminal is equal to or greater than (or greater than) or less than (or less than) a second threshold value, a third condition related to whether a cell quality value of a direct path is equal to or greater than (or greater than) or less than (or less than) a third threshold value, or a fourth condition related to whether a quality value associated with at least one indirect path is equal to or greater than (or greater than) or less than (or less than) a fourth threshold value. And, each of the first threshold value, the second threshold value, the third threshold value and/or the fourth threshold value may be set/instructed by the base station or may be defined in advance.

That is, the first terminal can monitor whether at least one measurement value satisfies at least one condition described above. If at least one measurement value satisfies at least one condition described above, the first terminal can activate/deactivate the direct path or at least one indirect path.

For example, assume that the first condition is a condition on whether the altitude of the first terminal is equal to or greater than a first threshold value. If the altitude of the first terminal satisfies the first condition (i.e., the altitude of the first terminal is equal to or greater than the first threshold value), the first terminal can deactivate a direct path and/or activate at least one indirect path.

Additionally or alternatively, assume that the first condition is a condition on whether the altitude of the first terminal is less than (or below) a first threshold value. If the altitude of the first terminal satisfies the first condition (i.e., the altitude of the first terminal is less than (or below) the first threshold value), the first terminal can activate the direct path and/or deactivate at least one indirect path.

Additionally or alternatively, assume that the second condition is a condition on whether the speed of the first terminal is equal to or greater than a first threshold value. If the speed of the first terminal satisfies the second condition (i.e., the speed of the first terminal is equal to or greater than the second threshold value), the first terminal can deactivate the direct path and/or activate at least one indirect path.

Additionally or alternatively, assume that the second condition is a condition on whether the speed of the first terminal is less than (or below) a first threshold. If the speed of the first terminal satisfies the second condition (i.e., the speed of the first terminal is less than (or below) the second threshold), the first terminal can activate the direct path and/or deactivate at least one indirect path.

Additionally or alternatively, assume that the third condition is a condition on whether the cell quality value of the direct path is equal to or greater than a third threshold value. If the cell quality value of the direct path satisfies the third condition (i.e., the cell quality value is equal to or greater than the third threshold value), the first terminal can activate the direct path and/or deactivate at least one indirect path.

Additionally or alternatively, assume that the third condition is a condition on whether the cell quality value of the direct path is less than or equal to a third threshold. If the cell quality value of the direct path satisfies the third condition (i.e., the cell quality value is less than or equal to the third threshold), the first terminal can deactivate the direct path and/or activate at least one indirect path.

Additionally or alternatively, assume that the fourth condition is a condition on whether a quality value associated with at least one indirect path is equal to or greater than a fourth threshold. If the quality value associated with at least one indirect path satisfies the fourth condition (i.e., the quality value is equal to or greater than the fourth threshold), the first terminal can deactivate the direct path and/or activate at least one indirect path.

Additionally or alternatively, assume that the fourth condition is a condition on whether a quality value associated with at least one indirect path is less than or equal to a fourth threshold. If the quality value associated with at least one indirect path satisfies the fourth condition (i.e., the quality value is less than or equal to the fourth threshold), the first terminal can activate the direct path and/or deactivate the at least one indirect path.

As an example of the present disclosure, based on the activation or deactivation of a direct path or at least one indirect path, the first terminal may transmit information related to the activation or deactivation to the base station or the second terminal. For example, the information related to the activation or deactivation may include information about the activated or deactivated path, at least one measurement value, or/and a condition/measurement value associated with the activation or deactivation of the path.

For example, the first terminal may transmit information related to activation or deactivation to the base station and/or the second terminal via uplink control information (UCI), a medium access control (MAC) control element (CE), or a radio resource control (RRC) message.

For example, based on at least one indirect path being disabled, at least one of a sidelink (SL) bandwidth part (BWP) or a SL configured grant (CG) setting on at least one indirect path may be disabled or released.

As another example, based on the direct path being disabled, at least one of a semi-persistence scheduling (SPS) setting, a BWP setting, a CG setting, a sounding reference signal (SRS) setting, and a physical uplink control channel (PUCCH) setting related to the direct path may be disabled or released.

As another example, based on the activation of the direct path, the first terminal may perform a random access procedure related to the direct path to transmit information related to the activation to the base station.

As another example, based on at least one indirect path being activated, the first terminal can transmit information related to the activation to the base station and/or the second terminal via the at least one indirect path.

The method described in the example of FIG. 10 can be performed by the first device (100) of FIG. 14. That is, the first terminal of FIG. 10 can be implemented as the first device (100). For example, one or more processors (102) of the first device (100) of FIG. 14 can receive first configuration information related to a direct path and at least one indirect path from a base station through one or more transceivers (106).

Furthermore, one or more memories (104) of the first device (100) may store instructions for performing the method described in the example of FIG. 14 or the examples described below when executed by one or more processors (102).

FIG. 11 is a diagram for explaining a process in which a base station performs communication according to one embodiment of the present disclosure.

The base station can transmit first configuration information related to a direct path and at least one indirect path to the terminal (1110).

The configuration related to the first setting information has been described with reference to Fig. 10, so any duplicate description will be omitted.

Based on at least one measurement value acquired by the first terminal satisfying at least one condition, the base station can receive information related to activation or deactivation of a direct path or at least one indirect path from the first terminal (S1120).

For example, when at least one measurement value acquired by the first terminal satisfies at least one condition, the direct path or at least one indirect path can be activated or deactivated by the first terminal. Then, the base station can receive information related to the activation or deactivation of the direct path or the at least one indirect path from the first terminal.

The method described in the example of FIG. 11 can be performed by the second device (200) of FIG. 14. That is, the base station of FIG. 11 can be implemented by the second device (200). For example, one or more processors (202) of the second device (200) of FIG. 14 can transmit first configuration information related to a direct path and at least one indirect path to a terminal through one or more transceivers (206). The one or more processors (202) can receive information related to activation or deactivation of the direct path or at least one indirect path through one or more transceivers (206).

Furthermore, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of FIG. 11 or the examples described below when executed by one or more processors (202).

FIG. 12 is a diagram for explaining a multi-path scenario according to one embodiment of the present disclosure.

As an example of the present disclosure, as illustrated in FIG. 12, the first terminal is a terminal device used by a user boarding a specific means of transportation (e.g., an airplane, a ship, a plane, etc.), and the second terminal may be mounted on UAM (unmanned aerial mobility). For example, the first terminal and the second terminal may be connected via sidelink or/Wi-Fi-based communication, but is not limited thereto. The first terminal and the second terminal may perform NTN-based communication.

For example, the direct path of a multipath relay may provide RRC signals, while the indirect path of a multipath relay via UAM may provide passenger user data.

Hereinafter, operations related to direct paths and indirect paths for multi-path operations described with reference to FIGS. 10 to 12 will be specifically described. The first terminal, the second terminal, and the base station of FIGS. 10 to 12 can perform operations according to the embodiments described below and combinations of the embodiments described above.

Example 1

In one embodiment of the present disclosure, the base station can transmit an RRC message to the relay terminal and/or the remote terminal for configuring one or more cells. Additionally, one or more indirect paths and/or direct paths for the relay terminal can be configured in the one or more cells, and the one or more indirect paths and/or direct paths can be transmitted from the base station via the RRC message. Here, one serving cell can correspond to one direct cell.

When direct path(s) are established for multiple serving cells, different direct paths or a single direct path can be established for different serving cells by RRC messages. Different serving cells can be addressed by different serving cell indices in the RRC message.

When an indirect path is established for multiple relay terminals, all or a subset of different relay terminals can be established for different indirect paths or a single indirect path by RRC messages. Different direct paths and indirect paths can be addressed with different path indices, and different relay terminals can be addressed with different relay terminal indices in the RRC messages.

When multiple carriers (e.g., multiple sidelink carriers) are established for an indirect path between a remote terminal and a relay terminal, different carriers or a subset of carriers for different indirect paths or a single indirect path can be established by RRC messages. Different carriers can be addressed by different carrier indices in the RRC messages.

As an example of the present disclosure, a terminal receiving an RRC message can initially set each path to be activated or deactivated as follows.

- Each configured direct cell can be initially set as an activated cell (or a deactivated cell).

- Each configured relay terminal can be initially set as an activated relay (or a deactivated relay).

- Each direct path established can be initially set as an active path (or a disabled path).

- Each established indirect path can be initially set as an active path (or a disabled path).

As an example of the present disclosure, control information (e.g., MAC CE or DCI) received by a terminal from a base station may indicate at least one of the following information/statuses:

- Each configured direct cell can be activated or deactivated depending on its serving cell index.

- Each configured relay terminal can be activated or deactivated depending on its relay terminal index.

- Each direct route established can be activated or deactivated depending on its route index.

- Each established indirect path can be activated or deactivated using its path index.

As an example of the present disclosure, a terminal that has received the control information may perform at least one of the following operations.

- If the control information indicates that a specific configured direct cell is activated or deactivated, the terminal may activate or deactivate the direct cell corresponding to the serving cell index as indicated.

- If the control information indicates that a specific configured relay terminal is activated or deactivated, the terminal may activate or deactivate the relay terminal corresponding to the relay terminal index as indicated.

- If the control information indicates that a specific configured direct path is activated or deactivated, the terminal may activate or deactivate the direct path corresponding to the path index as indicated.

- If the control information indicates that a specific configured indirect path is activated or deactivated, the terminal may activate or deactivate the indirect path corresponding to the path index as indicated.

Example 1-1

Example 1-1 relates to a method for activating/deactivating an indirect path/direct path depending on a measurement result.

If autonomous activation/deactivation is set by the base station based on detection of altitude or speed of the remote terminal or detection of Uu/SL measurement results above or below a threshold set by the base station, the remote terminal may autonomously activate, deactivate or release the direct path or the indirect path of the multipath relay to the remote terminal as described below, before/after notifying the base station and/or the relay terminal about the detected event and/or the measured Uu cell quality of the direct path and/or the measured SL quality of the indirect path.

- If the altitude of the remote terminal is equal to or higher than the altitude threshold set by the base station, the remote terminal may disable the direct path and enable the indirect path. As another example, if the altitude of the remote terminal is equal to or higher than the altitude threshold set by the base station, the remote terminal may disable the direct path or enable the indirect path.

- If the altitude of the remote terminal is lower than the altitude threshold set by the base station, the remote terminal can activate the direct path and deactivate the indirect path. As another example, if the altitude of the remote terminal is lower than the altitude threshold set by the base station, the remote terminal can activate the direct path or deactivate the indirect path.

- If the measured Uu cell quality of the direct path at the remote terminal is equal to or higher than a threshold set by the base station, the remote terminal may activate the direct path and deactivate the indirect path. As another example, if the measured Uu cell quality of the direct path at the remote terminal is equal to or higher than a threshold set by the base station, the remote terminal may activate the direct path or deactivate the indirect path.

- If the measured Uu cell quality of the direct path from the remote terminal is lower than the threshold set by the base station, the remote terminal may disable the direct path and enable the indirect path. As another example, if the measured Uu cell quality of the direct path from the remote terminal is lower than the threshold set by the base station, the remote terminal may disable the direct path or enable the indirect path.

- If the measured SL quality of the indirect path at the remote terminal or relay terminal is equal to or higher than the threshold set by the base station, the remote terminal may deactivate the direct path and activate the indirect path.

- If the measured SL quality of the indirect path of the remote terminal or relay terminal is lower than the threshold set by the base station, the remote terminal may activate the direct path and deactivate the indirect path. If the measured SL quality of the indirect path of the remote terminal or relay terminal is lower than the threshold set by the base station, the remote terminal may activate the direct path or deactivate the indirect path.

As an example of the present disclosure, when the indirect path is activated upon detection of an event as described above (e.g., an event related to a comparison between altitude and/or cell quality and a threshold set by a base station), the relay terminal may activate the indirect path based on a measured SL quality of an indirect path of the remote or relay terminal exceeding the threshold, or/and based on a measured Uu cell quality of a direct path of the remote terminal exceeding the threshold, or/and based on a measured Uu cell quality of an indirect path of the relay terminal exceeding the threshold, or/and upon receiving information from the remote terminal (e.g., information related to the event, etc.).

Additionally or alternatively, if the indirect path is deactivated upon detection of an event as described above (e.g., an event related to a comparison between altitude and/or cell quality and a threshold set by the base station), the relay terminal may deactivate the indirect path based on a measured SL quality of the indirect path from a remote or relay UE below the threshold, or/and based on a measured Uu cell quality of the direct path from a remote UE above the threshold, or/and based on a measured Uu cell quality of the indirect path from a relay UE below the threshold, or/and upon receiving information from the remote terminal (e.g., information related to the above event, etc.).

Additionally or alternatively, if the base station has not configured autonomous activation/deactivation, the remote terminal may receive control information (e.g., MAC CE or DCI) indicating one or more of the following:

- Each configured direct cell can be activated or deactivated with its serving cell index.

- Each configured relay terminal can be activated or deactivated with its corresponding relay terminal index.

- Each direct path configured can be activated or deactivated with its path index.

- Each configured indirect path can be activated or deactivated with its path index.

Example 1-2

Embodiment 1-2 relates to the actions performed by the remote terminal after the direct path is deactivated or released. That is, when the direct path is deactivated due to autonomous activation/deactivation or reception of control information from the base station, the remote terminal may deactivate or release the direct path (and the PCell of the direct path) and perform one of the options described below.

Option 1

A remote terminal may regard the PCell of a relay terminal in an indirect path as the PCell of the remote terminal. That is, the PCell of the remote terminal may be changed to the PCell of the relay terminal as described below.

For option 1, the base station may provide a conditional reset to the remote UE and/or the relay terminal for the PCell change before the deactivation of the direct path. Therefore, when the direct path is deactivated, the remote terminal may consider that the condition of the conditional reset is satisfied and may apply the conditional reset to the direct path and the indirect path to perform the PCell change of the remote terminal. When the direct path is deactivated or information is received from the remote terminal, the relay terminal may also consider that the condition of the conditional reset is satisfied and may apply the conditional reset to the indirect path to perform the PCell change of the remote UE.

Option 2

The PCell of the remote terminal is maintained but may be deactivated. That is, the PCell is not changed but may be deactivated as described below.

For option 2, the base station may provide a conditional reset to the remote terminal and/or the relay terminal for the deactivation prior to the deactivation of the direct path. Accordingly, when the direct path is deactivated, the remote terminal may consider that the condition of the conditional reset is satisfied and apply the conditional reset to the direct path and the indirect path. When the direct path is deactivated or information is received from the remote terminal, the relay terminal may also consider that the condition of the conditional reset is satisfied and apply the conditional reset to the indirect path.

For example, when direct path is disabled, the remote terminal can change the default path of all split SRBs from the direct path to the indirect path. If the default path of a split DRB is set to the direct path, the default path of the DRB can also be changed to the indirect path.

Additionally or alternatively, when direct path is disabled, the remote terminal may change from direct SRB to indirect SRB upon conditional reset. If direct path DRB is established, the direct DRB may also change to indirect DRB or be released upon conditional reset.

Additionally or alternatively, when direct path is disabled, the remote terminal may not perform one or some or all of the following actions:

- Uu RLM (radio link monitoring) on direct path

- PDCCH monitoring on direct path

- Receive broadcast system information from direct path

- Paging monitoring on direct path

Additionally or alternatively, if the remote terminal does not perform Uu RLM on the direct path, upon detecting an indirect path failure, the remote terminal may activate the direct path and report the indirect path failure to the base station. If the remote terminal fails to activate the direct path or fails to report the indirect path failure to the base station, the remote terminal may initiate an RRC connection re-establishment procedure.

Additionally or alternatively, if the remote terminal does not perform Uu RLM on the direct path, upon detecting an indirect path failure, the remote terminal may initiate an RRC connection re-establishment procedure without activating the direct path.

For example, when the direct path is disabled, the remote terminal may disable or release the SPS configuration, the CG configuration, the SRS configuration, the active BWP of the direct path, the PUCCH configuration, or/and the supplemental UL carrier.

For example, if a direct path becomes disabled, the remote terminal may stop or suspend any timers associated with the direct path.

Example 1-3

In one embodiment of the present disclosure, when autonomous activation/deactivation or reception of control information from a base station is applied, the remote terminal may still consider the PCell of the direct path as activated but deactivate the uplink of the direct path according to at least one of the examples described below.

As an example of the present disclosure, the base station can provide a conditional reset to the remote terminal and/or the relay terminal before the uplink deactivation of the direct path. Accordingly, when the uplink of the direct path is deactivated, the remote terminal can consider that the condition of the conditional reset is satisfied and apply the conditional reset to the direct path and the indirect path. When the uplink of the direct path is deactivated or information is received from the remote terminal, the relay terminal can also consider that the condition of the conditional reset is satisfied and apply the conditional reset to the indirect path.

As an example of the present disclosure, when the uplink of the direct path is disabled, the remote terminal can change the default path of all split SRBs from the direct path to only the indirect path of the uplink. If the default path of the split DRB is set to the direct path, the default path of the DRB can also be changed to only the indirect path of the uplink.

As an example of the present disclosure, when the uplink of the direct path is disabled, the remote terminal can change from a direct SRB to an indirect SRB only for the uplink according to a conditional reset. When a direct path DRB is set, the direct DRB can also be changed to an indirect DRB or released only for the uplink according to a conditional reset.

As an example of the present disclosure, even when the uplink of the direct path is disabled, the remote terminal may perform one, some, or all of the following actions:

- Uu RLM (radio link monitoring) on direct path

- PDCCH monitoring on direct path

- Receive broadcast system information from direct path

- Paging monitoring on direct path

As an example of the present disclosure, if an indirect path failure or a direct path failure is detected, the remote terminal may activate the uplink of the direct path and report the indirect path failure or the direct path failure to the base station. If the remote terminal fails to activate the uplink of the direct path or fails to report the path failure to the base station, the remote terminal may initiate an RRC connection re-establishment procedure.

Additionally or alternatively, if the remote terminal does not perform Uu RLM on the direct path, upon detecting a path failure, the remote terminal may initiate an RRC connection re-establishment procedure without activating the uplink of the direct path.

As an example of the present disclosure, when the uplink of the direct path is disabled, the remote terminal can disable or release at least one of the SPS setting, the CG setting, the SRS setting, the active BWP of the direct path, the PUCCH setting, or/and the supplemental UL carrier.

As an example of the present disclosure, when a direct path becomes inactive, the remote terminal may stop or suspend all timers associated with the direct path.

Example 1-4

In one embodiment of the present disclosure, when the indirect path is disabled by autonomous activation/deactivation or reception of control information from the base station, the remote terminal can disable the indirect path and perform at least one of the examples described below.

As an example of the present disclosure, before disabling an indirect path, the base station can provide a conditional reset to the remote terminal and/or the relay terminal for the disabling. Accordingly, when disabling the indirect path, the remote terminal can consider that the condition of the conditional reset is satisfied and apply the conditional reset to the direct path and the indirect path. When disabling the indirect path or receiving information from the remote terminal, the relay terminal can also consider that the condition of the conditional reset is satisfied and deactivate or release the indirect path according to the conditional reset.

As an example of the present disclosure, when the PCell of the direct path is deactivated, the remote terminal can activate the direct path and the PCell of the direct path and trigger a random access procedure for the PCell when the indirect path is deactivated.

Additionally or alternatively, if the direct path is disabled, the remote terminal may activate the direct path (or the PCell of the direct path if disabled), perform cell selection or reselection, and trigger a random access procedure for the selected cell. If the random access procedure for the selected cell is successful, the remote terminal may consider the selected cell as the new PCell of the remote terminal and apply a conditional reset.

As an example of the present disclosure, when the PCell of the remote terminal is in the indirect path, when the indirect path is deactivated, the remote terminal can perform cell selection or reselection and trigger a random access procedure for the selected cell. If the random access procedure for the selected cell is successful, the remote terminal can regard the selected cell as the PCell of the remote UE. That is, the PCell of the remote UE is changed to the selected cell, and a conditional reset can be applied to the direct path and/or the indirect path. The remote terminal can deactivate or release the indirect path according to the conditional reset for the indirect path.

As an example of the present disclosure, when the uplink of the direct path is disabled, when the indirect path is disabled, the remote terminal can activate the uplink of the direct path and trigger a random access procedure for the PCell.

As an example of the present disclosure, when an indirect path is disabled, if the default path of a split SRB or split DRB is set to a direct path, the default path of the SRB or DRB may also be changed to an indirect path.

As an example of the present disclosure, when a direct path is disabled, a remote terminal can change from an indirect SRB to a direct SRB based on a conditional reconfiguration. When an indirect path DRB is established, the indirect DRB can also be changed to a direct DRB or released based on a conditional reconfiguration.

As an example of the present disclosure, when an indirect path is disabled, the remote terminal may not perform one, some, or all of the following actions:

- SL RLF detection in indirect path

- SCI monitoring on SL carriers in indirect paths

- Receiving broadcast SL-BCH from SL carrier in indirect path

As an example of the present disclosure, if the remote terminal does not perform SL RLF detection on the indirect path, when a direct path failure is detected, the remote terminal may activate the indirect path and report the direct path failure to the base station. If the remote terminal fails to activate the indirect path or fails to report the direct path failure to the base station, the remote terminal may initiate an RRC connection re-establishment procedure.

Additionally or alternatively, if the remote terminal does not perform SL RLF detection on the indirect path, when a direct path failure is detected, the remote terminal may initiate an RRC connection re-establishment procedure without activating the indirect path.

As an example of the present disclosure, when an indirect path is deactivated, the remote terminal may deactivate or release the SL CG setting and/or the activated SL BWP on the indirect path.

As an example of the present disclosure, when an indirect path is disabled, the remote terminal may stop or suspend all timers associated with the indirect path (e.g., all timers associated with SL transmission and reception of the indirect path).

Example 2

In one embodiment of the present disclosure, a terminal for which a direct path and/or an indirect path is established may measure at least one of its altitude, speed, Uu cell quality of the direct path or SL quality of the indirect path, and perform at least one of the operations described below according to the measurement result.

- If the altitude or/and speed of the terminal is higher than the preset/defined altitude or/and speed, the terminal may deactivate the direct route. In addition, the terminal may report information related to the deactivation of the direct route (e.g., information related to the event that deactivated the direct route, information about the deactivated route, etc.) to the base station.

- If the altitude or/and speed of the terminal is lower than or equal to a preset/defined altitude or/and speed, the terminal may activate a direct route. In addition, the terminal may report information related to the activation of the direct route (e.g., information related to the event that activated the direct route, information about the activated route, etc.) to the base station.

- If the altitude and/or speed of the terminal is higher than the preset/defined designated altitude and/or speed, the terminal may activate the indirect path. In addition, the terminal may report information related to the activation of the indirect path (e.g., information related to the event that activated the indirect path, information about the activated path, etc.) to the base station.

- If the altitude or/and speed of the terminal is lower than the preset/defined altitude or/and speed, the terminal may deactivate the indirect path. In addition, the terminal may report information related to the deactivation of the indirect path (e.g., information related to the event that deactivated the indirect path, information about the activated path, etc.) to the base station.

- If the Uu cell quality value (measured by the terminal) is lower than or equal to a preset/defined Uu threshold, the terminal may deactivate the direct path. In addition, the terminal may report information related to the deactivation of the direct path (e.g., information related to the event that deactivated the direct path, information about the deactivated path, etc.) to the base station.

- If the Uu cell quality value (measured by the terminal) is greater than or equal to a preset/defined Uu threshold, the terminal may activate a direct path. In addition, the terminal may report information related to the activation of the direct path (e.g., information related to the event that activated the direct path, information about the activated path, etc.) to the base station.

- If the Uu cell quality value (measured by the terminal) is less than or equal to a preset/defined Uu threshold, the terminal may activate an indirect path. Then, the terminal may report information related to the activation of the indirect path (e.g., information related to the event that activated the indirect path, information about the activated path, etc.) to the base station.

- If the Uu cell quality value (measured by the terminal) is greater than or equal to a preset/defined Uu threshold, the terminal may deactivate the indirect path. In addition, the terminal may report information related to the deactivation of the indirect path (e.g., information related to the event that deactivated the indirect path, information about the activated path, etc.) to the base station.

- If the SL quality value (measured by the terminal) is higher than the preset/defined SL threshold, the terminal may deactivate the direct path. In addition, the terminal may report information related to the deactivation of the direct path (e.g., information related to the event that deactivated the direct path, information about the activated path, etc.) to the base station.

- If the SL quality value (measured by the terminal) is lower than or equal to a preset/defined SL threshold, the terminal may activate a direct path. In addition, the terminal may report information related to the activation of the direct path (e.g., information related to the event that activated the direct path, information about the activated path, etc.) to the base station.

- If the SL quality value (measured by the terminal) is greater than or equal to the preset/defined SL threshold, the terminal may activate the direct path. In addition, the terminal may report information related to the activation of the indirect path (e.g., information related to the event that activated the indirect path, information about the activated path, etc.) to the base station.

- If the SL quality value (measured by the terminal) is lower than or equal to a preset/defined SL threshold, the terminal may deactivate the indirect path. In addition, the terminal may report information related to the deactivation of the indirect path (e.g., information related to the event that deactivated the indirect path, information about the activated path, etc.) to the base station.

Example 3

Example 3 relates to a set of at least two indirect paths through different relay terminals without (or with) a direct link to a remote terminal.

One or more indirect paths may be established for the remote terminal through the same or different relay terminals. Additionally, one or more direct paths may be established for the remote terminal, or no direct path may be established. Different indirect paths may be established on different sidelink carriers between the remote terminal and the same relay terminal. Alternatively, different indirect paths may be established using different relay terminals on the same or different sidelink carriers between the remote terminal and different relay terminals.

A remote terminal can be configured as multiple candidate U2N relay terminals. Only one configured relay terminal can be activated for a remote terminal, or more than one configured relay terminal can be activated for a remote terminal by RRC message, MAC CE or DCI.

A remote terminal may be configured with one or more sidelink carriers having identical or multiple configured U2N relay terminals. Only one sidelink carrier may be activated for each relay terminal or remote terminal, or more than one configured relay terminal may be activated for each relay terminal or remote terminal by RRC message or MAC CE or DCI.

The base station can transmit the path activation/deactivation MAC CE to the remote terminal via the direct path and/or the indirect path. In Case 2, the relay terminal can receive the MAC CE from the base station (i.e., the DL MAC CE in the indirect path from the base station to the relay terminal), and then relay the MAC CE to the remote terminal. The relay terminal can generate the relayed MAC CE (i.e., the DL MAC CE in the direct path from the base station to the remote terminal or the SL MAC CE in the indirect path from the relay terminal to the remote terminal) to be transmitted to the remote terminal based on Case 1. As another example, the relay terminal can relay the MAC CE received from the base station to the remote terminal without changing the MAC CE, as in Case 2.

As one embodiment of the present disclosure, FIG. 13 illustrates a path activation/deactivation MAC CE. A MAC CE according to Case 1 (e.g., a MAC CE of FIG. 13 (a)) may correspond to a MAC CE of a direct path from a base station to a remote terminal, or may correspond to a MAC CE of an indirect path from a relay terminal to a remote terminal. A MAC CE according to Case 2 (e.g., a MAC CE of FIG. 13 (b)) may correspond to a MAC CE of an indirect path from a base station to a relay terminal.

The D _i field of the MAC CE according to Case 1 and 2 may indicate whether the corresponding path with index i is activated or deactivated for the remote terminal. For the MAC CE, a specific index i may be set to a specific direct path or a specific indirect path by an RRC message from the base station to the terminal. If the index is not set, the corresponding D _i field is invalid and thus the terminal may ignore the field. If the index 0 is not set, the corresponding D ₀ field may indicate activation or deactivation of the direct path in the PCell. The D _i field of the MAC CE set to a value of '0' indicates deactivation of the corresponding path with index i, and the D _i field of the MAC CE set to a value of '1' indicates activation of the corresponding path with index i, and vice versa.

The UE ID field of the MAC CE according to Case 2 may indicate the UE ID of the remote terminal. When the relay terminal receives the MAC CE according to Case 2, the relay terminal may transmit the MAC CE according to Case 1 or Case 2 to the remote terminal corresponding to the UE ID included in the MAC CE received from the base station. In the case of the MAC CE according to Case 2 transmitted to the remote terminal, the MAC CE according to Case 2 received from the base station may be copied to the MAC CE according to Case 2 generated by the relay terminal. In the case of the MAC CE according to Case 1 transmitted to the remote terminal, the first octet of the MAC CE according to Case 2 received from the base station may be copied to the MAC CE according to Case 1 generated by the relay terminal. The UE ID field may be N bits in size of one or more octets depending on which UE ID is used in the MAC CE.

The base station can determine/set the type of MAC CE used for each of the remote terminal and the relay terminal. That is, the base station can set which case/MAC CE among the MAC CE of (a) of Fig. 13 (e.g., the MAC CE according to Case 1) or the MAC CE of (b) (e.g., the MAC CE according to Case 2) is used for the remote terminal and the relay terminal. Additionally or alternatively, the relay terminal or the remote terminal can set which case/MAC CE among the MAC CEs illustrated in Fig. 13 is used for the MAC CE from the relay terminal to the remote terminal. The relay terminal (or the remote terminal) can indicate the case of the set format to the remote terminal (or the relay terminal).

The base station can transmit MAC CE to the remote terminal/relay terminal via direct path or indirect path depending on one or more of the following options.

- Option 1: The base station can transmit MAC CE-based enable/disable status either directly (i.e., if enabled) or indirectly (i.e., if direct path is not enabled/established).

- Option 2: The base station can transmit MAC CE based on the measured results.

For example, if the measured quality is higher than a threshold or the measured quality on the indirect path is lower than the threshold, the base station may transmit MAC CE on the direct path.

As another example, if the measured quality is lower than the threshold and the measured quality on the indirect path exceeds the threshold, the base station may transmit MAC CE on the indirect path.

For example, the quality measured on the direct path may be Uu RSRP, Uu RSRQ or Uu RSSI, and the quality measured on the indirect path may be SL-RSRP, SL-RSRQ, SL-RSSI or CBR (channel utilization).

- Option 3: The base station can transmit MAC CE based on the primary path. For example, if the direct path corresponds to the primary path, the base station can transmit MAC CE based on the direct path. If the indirect path corresponds to the primary path, the base station can transmit MAC CE based on the indirect path.

When a MAC CE is received, if configured by the base station, the relay terminal can activate or deactivate a specific path belonging only to the relay terminal according to the MAC CE. The configuration can be provided on a path-by-path basis, on a remote-by-terminal basis or on a relay-by-terminal basis for activation-only or deactivation-only or both. If not configured by the base station, the relay terminal may not deactivate a specific activated path belonging to the relay terminal according to the MAC CE even if the remote terminal deactivates the corresponding path. If not configured by the base station, the relay terminal may not activate a specific disabled path belonging to the relay terminal according to the MAC CE even if the remote terminal activates the corresponding path.

After receiving a DL MAC CE, if configured by the base station, the relay terminal may transmit a SL MAC CE or SCI indicating activation or deactivation of a specific path depending on the MAC CE received from the base station.

When SCI is enabled/configured, an SCI specifying an address of a remote terminal may be transmitted to the remote terminal over a unicast sidelink. The SCI may include a bitmap where each bit indicates activation or deactivation of the corresponding path with index i. If the SCI indicates SL HARQ-ACK, the remote terminal may transmit ACK or NACK to the relay terminal upon receiving the SCI. The SL slot used for SL HARQ-ACK transmission may be determined based on the application time upon SCI reception or the SCI indicating an explicit slot. In the case of the SCI indicating an explicit slot, the relay terminal may set an explicit slot based on the DL MAC CE transmission time or the RRC configuration by the base station.

When SL MAC CE is used/configured, SL MAC CE based on Case 1 can be transmitted to the remote UE over unicast sidelink. If the SCI scheduling the SL MAC CE indicates SL HARQ-ACK, the remote UE can transmit ACK or NACK to the relay UE as soon as it receives the SL MAC CE. The SL slot used for SL HARQ-ACK transmission can be determined based on the application time according to SCI/SL MAC CE reception or the SCI indicating an explicit slot. In case of the SCI indicating an explicit slot, the relay UE can set an explicit slot based on the DL/SL MAC CE transmission time or the RRC configuration by gNB.

A remote terminal that has received a DL MAC CE or SL MAC CE or SCI indicating UE activation or deactivation may activate or deactivate a specific path according to the DL MAC CE or SL MAC CE or SCI indicating UE activation or deactivation after the application time.

Example 3-1

When one or more indirect paths becomes disabled, the remote terminal may perform one or more of the following options for the indirect path from the start of the first step of the disabled state of the indirect path:

Option 1: The remote terminal may not monitor SCI on the sidelink of the indirect path.

- Upon receiving an RRC message, Path Activation/Deactivation MAC CE or DCI indicating activation of the indirect path, the remote terminal can activate the indirect path and start monitoring SCI on the sidelink of the indirect path.

Option 1A: The relay terminal of the indirect path may not monitor the SCI of the remote terminal. At this time, when the relay terminal receives a Uu RRC message indicating activation of the indirect path, a path activation/deactivation MAC CE or DCI from the base station, the relay terminal may activate the indirect path and start monitoring SCI on the sidelink of the indirect path.

- Option 1B: The relay terminal of the indirect path can monitor the SCI of the remote terminal.

At this time, if a sidelink RRC message, path activation/deactivation MAC CE or DCI is received from a remote terminal indicating activation of an indirect path, or if a sidelink RRC message, path activation/deactivation MAC CE or DCI is received from a base station indicating activation of an indirect path, the relay terminal can activate the indirect path and start monitoring SCI on the sidelink of the indirect path.

Option 2: Short SL DRX cycle or no SL DRX cycle can be changed to long SL DRX cycle according to the periodic generation/transmission time of Keep-Alive message when SCI monitoring is performed. Here, Keep-alive message can be PC5-S signal for PC5 unicast link maintenance. SCI (e.g., SCI scheduling keep-alive message) or keep-alive message of one UE can indicate activation of indirect path or maintenance of indirect path in disabled state to another UE.

- Upon receiving an RRC message, MAC CE or DCI indicating activation of an indirect path from a base station, if the indirect path is deactivated, the relay terminal may transmit an SCI or a connection keep-alive message indicating activation of the indirect path to the remote terminal.

- Upon receiving an RRC message, MAC CE or DCI from the base station indicating deactivation of the indirect path, if the indirect path is activated, the relay terminal may send an SCI or keep-alive message indicating deactivation of the indirect path to the remote terminal.

- Upon receiving an RRC message, MAC CE or DCI indicating activation of an indirect path from a base station, if the indirect path is deactivated, the remote terminal may transmit an SCI or connection keep-alive message indicating activation of the indirect path to the relay terminal.

- Upon receiving an RRC message, MAC CE or DCI indicating deactivation of the indirect path from the base station, if the indirect path is activated, the remote terminal may transmit an SCI or a keep-alive message indicating deactivation of the indirect path to the relay UE.

- Upon receiving an SCI or Keep-alive message from a relay terminal indicating activation of an indirect path, the remote terminal can activate the indirect path if it is inactive.

- Upon receiving an SCI or Keep-alive message from a relay terminal indicating deactivation of an indirect path, the remote terminal may deactivate the indirect path if it is activated.

- Upon receiving an SCI or Keep-Alive message indicating indirect path activation from a remote terminal, the relay terminal can activate the indirect path if it is disabled.

- Upon receiving an SCI or Keep-Alive message indicating deactivation of the indirect path from a remote UE, the relay terminal may deactivate the indirect path if it is activated.

Option 3: Short SL DRX cycle or no SL DRX cycle can be changed to long SL DRX cycle when SCI monitoring situation matches periodic or aperiodic SL-CSI reporting trigger.

- When a SCI monitoring situation occurs due to a long DRX cycle, aperiodic or periodic reports can be triggered and/or transmitted on the sidelink.

- Upon receiving an SCI that triggers an SL-SCI report from a relay terminal, the remote terminal can activate (or deactivate) the indirect path if it is deactivated (or activated).

- A remote terminal that receives an SL-SCI report from a relay terminal and an SCI that triggers indirect path activation (or deactivation) can activate (or deactivate) the indirect path if the indirect path is deactivated (or activated).

- After receiving an SCI that triggers an SL-SCI report from a remote terminal, the relay terminal can activate (or deactivate) the indirect path if it is deactivated (or activated).

- A relay terminal that receives an SCI triggering SL-SCI reporting and activation (or deactivation) of an indirect path from a remote terminal can activate (or deactivate) the indirect path if it is deactivated (or activated).

- After activation, the remote terminal can start PC5-RSRP measurement on the relay terminal. Or, in the deactivated state, the remote terminal can measure PC5-RSRP on the relay terminal.

Option 4: Discovery message-based activation

- The discovery message from another terminal can activate the indirect path if it is disabled, and deactivate the indirect path if it is enabled.

- All activity on the PC5 unicast link may be suspended (or behave almost as if it were disabled).

- At this time, when the indirect path is disabled, the remote terminal does not perform SL RLM and does not maintain the PC5 unicast link so that the SL RLF of the indirect path is not declared in the disabled state of the indirect path, but the remote terminal can continue to monitor the discovery message from the relay UE.

- Also, when the indirect path is disabled, the relay terminal does not maintain the PC5 unicast link and does not perform SL RLM, so the SL RLF of the indirect path is not declared in the indirect path disabled state, but the remote terminal can continue to monitor the discovery message of the relay terminal.

Option 4A: The relay terminal of the indirect path may not monitor the SCI of the remote terminal.

- Upon receiving an RRC message, MAC CE or DCI notifying indirect path activation from the base station, the relay terminal may transmit a discovery message notifying indirect path activation to the remote terminal if the indirect path is deactivated.

- Upon receiving an RRC message, MAC CE or DCI from the base station notifying deactivation of the indirect path, the relay terminal may transmit a discovery message notifying the deactivation of the indirect path to the remote terminal if the indirect path is activated.

- Upon receiving an RRC message, MAC CE or DCI notifying indirect path activation from the base station, the remote terminal may transmit a discovery message notifying indirect path activation to the relay terminal if the indirect path is deactivated.

- Upon receiving an RRC message, MAC CE or DCI notifying indirect path deactivation from the base station, the remote terminal may transmit a discovery message notifying indirect path deactivation to the relay terminal if the indirect path is activated.

- Upon receiving an SCI or discovery message indicating indirect path activation from a relay terminal, the remote terminal may activate the indirect path if it is disabled.

- Upon receiving an SCI or discovery message from a relay terminal instructing deactivation of an indirect path, the remote terminal may deactivate the indirect path if it is activated.

- Upon receiving an SCI or discovery message indicating indirect path activation from a remote terminal, the relay terminal may activate the indirect path if it is disabled.

- Upon receiving an SCI or discovery message from a remote terminal instructing deactivation of an indirect path, the relay terminal may deactivate the indirect path if it is enabled.

Option 4B: The relay terminal of the indirect path can monitor the SCI of the remote UE.

- Upon receiving a discovery message from a remote terminal indicating activation of an indirect path, or a Uu RRC message, path activation/deactivation MAC CE or DCI from a base station indicating activation of an indirect path, the relay terminal may activate the indirect path and start monitoring SCI on the sidelink of the indirect path.

Option 5: DL MAC CE or DCI of the direct path or SL MAC CE or SCI of the first indirect path can indicate activation or deactivation of the second indirect path. At this time, the terminal can receive SCI or SL MAC CE in the first indirect path, and the first indirect path can be the same as or different from the second indirect path.

- As an example of the present disclosure, DL MAC CE and SL MAC CE can be configured as shown in FIG. 13.

- The first indirect path can be any activated indirect path. Alternatively, the first indirect path can be a primary indirect path established by a base station or a remote terminal or a relay terminal. The primary indirect path can be activated or deactivated (semi-statically or dynamically) by the base station or the relay terminal or the remote terminal. Alternatively, the primary indirect path can be always activated.

- Below, the operation in case of activation or deactivation of the second indirect path is described.

When receiving an RRC message, DL MAC CE or DCI indicating activation of an indirect path from a base station, if the indirect path is deactivated, the relay terminal may transmit an SCI or SL MAC CE indicating activation of the indirect path to the remote terminal.

When receiving an RRC message, DL MAC CE or DCI indicating deactivation of the indirect path from the base station, if the indirect path is activated, an SCI or SL MAC CE indicating deactivation of the indirect path can be transmitted to the relay terminal.

When receiving an RRC message, DL MAC CE or DCI indicating activation of an indirect path from a base station, if the indirect path is deactivated, the remote terminal may transmit an SCI or SL MAC CE indicating activation of the indirect path to the relay terminal.

When receiving an RRC message, DL MAC CE or DCI indicating deactivation of the indirect path from the base station, if the indirect path is activated, the remote terminal may transmit an SCI or SL MAC CE indicating activation of the indirect path to the relay terminal.

Upon receiving an SCI or SL MAC CE indicating indirect path activation from a relay terminal, the remote terminal can activate the indirect path if it is disabled.

Upon receiving an SCI or SL MAC CE from a relay terminal indicating deactivation of an indirect path, the remote terminal may deactivate the indirect path if it is enabled.

Upon receiving an SCI or SL MAC CE indicating indirect path activation from a remote terminal, the relay terminal can activate the indirect path if it is disabled.

Upon receiving an SCI or SL MAC CE from a remote terminal indicating deactivation of an indirect path, the relay terminal may deactivate the indirect path if it is enabled.

Option 5B: The DL MAC CE or DCI of the direct path or the SL MAC CE or SCI of the indirect path can indicate activation or deactivation of the direct path.

- As an example of the present disclosure, DL MAC CE and SL MAC CE can be configured as shown in FIG. 13.

Below we describe the actions involved in activating or deactivating a direct path.

Upon receiving an RRC message, DL MAC CE or DCI indicating activation of the direct path from the base station, if the direct path is deactivated, the relay terminal may transmit an SCI or SL MAC CE indicating activation of the direct path to the remote terminal.

Upon receiving an RRC message, DL MAC CE or DCI from the base station indicating deactivation of the direct path, if the direct path is activated, the relay terminal may transmit an SCI or SL MAC CE indicating deactivation of the direct path to the remote terminal.

Upon receiving an RRC message, DL MAC CE or DCI indicating activation of a direct path from a base station, the remote terminal can activate the direct path if it is disabled.

Upon receiving an RRC message, DL MAC CE or DCI from the base station indicating deactivation of the direct path, the remote terminal may deactivate the direct path if it is disabled.

Upon receiving an SCI or SL MAC CE indicating direct path activation from a relay terminal, the remote terminal can activate the direct path if it is disabled.

Upon receiving an SCI or SL MAC CE from a relay terminal indicating deactivation of the direct path, the remote terminal may deactivate the direct path if it is enabled.

Example 3-2

If one or more of the direct paths is disabled, the remote terminal may disable only uplink transmission, or disable both uplink transmission and downlink reception for the disabled direct path, as follows:

To disable uplink transmission regardless of whether downlink reception is disabled, the remote terminal may perform one or more of the following options for the direct path in the disabled state:

Option 1: One or more or all of PUCCH, SRS, and PUSCH may not be transmitted on the direct path.

- Option 1A-1: The terminal may not perform PDCCH monitoring on the direct path.

- Option 1A-2: The terminal can perform PDCCH monitoring on the direct path.

- In Option 1A-2, PDCCH can activate RACH, PUCCH or SRS. As another example, in Option 1A-2, PDCCH can activate direct path.

- Option 1B-1: The terminal cannot trigger or perform RACH on the direct path.

If the direct path is disabled and there is an ongoing RACH, the UE may stop the ongoing RACH procedure on the direct path. Alternatively, the UE may continue performing the ongoing RACH procedure on the direct path but may not trigger a new RACH on the direct path.

- Option 1B-2: If triggered, the terminal can perform RACH on the direct path.

Option 2: HARQ-ACK/CSI report/SRS are transmitted, but PUSCH may not be transmitted on the direct path.

- If uplink transmission of the direct path is disabled, the primary path can be set as an indirect path per remote terminal, per DRB, per SRB, per cell, per radio bearer, per logical channel, per priority, or per QoS indicator. Or, only PUSCH may not be transmitted on the direct path.

PUSCH transmissions can be configured to be disallowed on a per remote terminal, per cell, per radio bearer, per logical channel, per priority, or per QoS indicator basis.

For example, indirect UL transmission may be allowed for delay tolerant packets, but direct UL transmission may be allowed for delay sensitive packets when the remote terminal is at the cell edge. Accordingly, PUSCH may be allowed for direct UL deactivation for the first bearer/logical channel/priority/QoS indicator, but PUSCH may not be allowed for direct UL deactivation for the second bearer/logical channel/priority/QoS indicator. In that option, the remote terminal may not monitor the DCI format scheduling PUSCH on the downlink of the direct path.

Option 3: HARQ-ACK/CSI reports are transmitted, but PUSCH and SRS may not be transmitted on the direct path.

Option 4: HARQ-ACK and aperiodic CSI reporting are transmitted, but PUSCH, SRS and periodic CSI reporting may not be transmitted on the direct path.

Option 5: HARQ-ACK is transmitted, but PUSCH, SRS and all CSI reports may not be transmitted on the direct path.

Option 6: For a direct path in the disabled state, HARQ-ACK enable/disable can be indicated by DCI, but for a direct path in the enabled state, HARQ-ACK enable/disable cannot be indicated by DCI.

Option 7: The terminal may consider HARQ-ACK as disabled for the direct path in the inactive state, but may consider HARQ-ACK as enabled for the direct path in the active state, or the enabling/disabling of HARQ-ACK for the direct path in the active state may be indicated by DCI.

Example 3-3

In one embodiment of the present disclosure, when the direct path is disabled (when the remote terminal is a reduced capability (RedCap) terminal and/or a normal UE with power saving mode), the remote terminal and the base station may disable the direct UL (i.e., UL of the direct path) but enable the direct DL (i.e., DL of the direct path).

As an example of the present disclosure, assume a case where direct UL is disabled. In this case, if the indirect path is disabled, the remote terminal may stop direct UL for uplink data of the remote terminal and activate the indirect path, or may still monitor PDCCH and receive PDSCH on the direct path.

As another example of the present disclosure, the remote terminal and the base station can optionally also disable indirect DL (i.e., downlink of the relay UE and/or SL transmission from the relay UE) for SL TX/RX power saving.

As another example of the present disclosure, the base station can activate or deactivate UL/DL of direct path by DCI or MAC CE, RRC. The DCI can be DCI scheduling DL PDSCH, UL PUSCH or SL PSSCH.

As another example of the present disclosure, if HARQ-ACK, CSI reporting and/or SR for the direct path is not allowed while the direct path is disabled by RRC configuration, the remote terminal can transmit HARQ-ACK, CSI reporting and/or SR through the indirect path as follows.

Upon receiving a DCI scheduling PDSCH with PUCCH allocation for HARQ-ACK, the remote terminal may indicate the following information to the relay terminal via SCI or SL MAC CE, if configured:

- K1 value and/or PUCCH resource indicator indicated by DCI

- HARQ-ACK information for TB of PDSCH received by remote terminal on direct path

If configured, aperiodic/periodic CSI reporting and/or SR (Scheduling Request) triggered by remote terminals may initiate sidelink transmissions to the relay UE.

- At startup, the remote terminal may allocate SL resources and transmit aperiodic/periodic CSI reporting and/or scheduling requests to the relay terminal via SCI and/or SL MAC CE and/or PC5-RRC messages.

Upon receiving the SCI and/or SL MAC CE and/or PC5-RRC message, the relay terminal can transmit the HARQ-ACK, CSI report and/or SR of the remote UE to the base station through the Uplink Control Information of PUCCH or PUSCH, UL MAC CE or UL RRC message.

- The relay terminal can receive PUCCH settings for the remote terminal from the base station for the above purpose.

As an example of the present disclosure, upon detection of an indirect path failure, a remote terminal may trigger a RACH for direct UL, resume direct UL, and suspend indirect UL.

As an example of the present disclosure, a base station can dynamically activate direct UL (and optionally direct DL PDCCH monitoring) (optionally deactivate indirect UL) in good coverage by DCI or MAC CE or RRC.

By the various embodiments described above, the network can establish direct paths and indirect paths for multi-path operation. In particular, if the terminal can support U2N relay function via SL, one of the paths according to the present disclosure can be dynamically activated or deactivated.

Previously, no mechanism was defined to provide multipath operation within a sidelink relay procedure. Various embodiments of the present disclosure enable a system to dynamically provide multipath operation including direct link and indirect link via U2N relay.

General description of devices to which the present disclosure may be applied

FIG. 14 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

Referring to FIG. 14, the first device (100) and the second device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR).

A first device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and/or one or more antennas (108). The processor (102) controls the memories (104) and/or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this disclosure.

For example, the processor (102) may process information in the memory (104) to generate first information/signal, and then transmit a wireless signal including the first information/signal through the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information/signal through the transceiver (106), and then store information obtained from signal processing of the second information/signal in the memory (104).

The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software codes including commands for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. Here, the processor (102) and the memory (104) may be part of a communication modem/circuit/chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and/or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and/or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present disclosure, a device may also mean a communication modem/circuit/chip.

The second device (200) includes one or more processors (202), one or more memories (204), and may additionally include one or more transceivers (206) and/or one or more antennas (208). The processor (202) may control the memories (204) and/or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this disclosure. For example, the processor (202) may process information in the memory (204) to generate third information/signal, and then transmit a wireless signal including the third information/signal via the transceiver (206). Additionally, the processor (202) may receive a wireless signal including fourth information/signal via the transceiver (206), and then store information obtained from signal processing of the fourth information/signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software codes including commands for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. Here, the processor (202) and the memory (204) may be part of a communication modem/circuit/chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and/or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and/or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present disclosure, a device may also mean a communication modem/circuit/chip.

Hereinafter, hardware elements of the device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, suggestions and/or methodologies disclosed in this disclosure, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this disclosure.

The one or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The one or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software configured to perform one or more of the following: included in one or more processors (102, 202), or stored in one or more memories (104, 204) and driven by one or more of the processors (102, 202). The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software in the form of codes, instructions and/or sets of instructions.

One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions and/or commands. The one or more memories (104, 204) may be comprised of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer readable storage media and/or combinations thereof. The one or more memories (104, 204) may be located internally and/or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

One or more transceivers (106, 206) can transmit user data, control information, wireless signals/channels, etc., as mentioned in the methods and/or flowcharts of the present disclosure, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals/channels, etc., as mentioned in the descriptions, functions, procedures, suggestions, methods and/or flowcharts of the present disclosure, from one or more other devices. For example, one or more transceivers (106, 206) can be coupled to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals/channels, and the like, as referred to in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this disclosure, via one or more antennas (108, 208). In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) may convert received user data, control information, wireless signals/channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals/channels, etc. using one or more processors (102, 202). One or more transceivers (106, 206) may convert processed user data, control information, wireless signals/channels, etc. from baseband signals to RF band signals using one or more processors (102, 202). For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and/or filter.

The embodiments described above are combinations of components and features of the present disclosure in a given form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented in a form that is not combined with other components or features. In addition, it is also possible to combine some components and/or features to form an embodiment of the present disclosure. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is obvious that claims that do not have an explicit citation relationship in the scope of the patent may be combined to form an embodiment or may be included as a new claim by post-application amendment.

It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics of the present disclosure. Accordingly, the above detailed description should not be construed as limiting in all respects but should be considered as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present disclosure are intended to be included in the scope of the present disclosure.

The scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on/in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure. The storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices, and can include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices remotely located from the processor(s). The memory or alternatively the non-volatile memory device(s) within the memory comprises a non-transitory computer readable storage medium. The features described in this disclosure may be incorporated into software and/or firmware stored on any one of the machine readable media to control the hardware of the processing system and to allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments/containers.

Here, the wireless communication technology implemented in the device (100, 200) of the present disclosure may include LTE, NR, and 6G, as well as Narrowband Internet of Things for low-power communication. At this time, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and/or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure may perform communication based on LTE-M technology. At this time, for example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, the LTE-M technology may be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, the ZigBee technology can create PAN (personal area networks) related to small/low-power digital communication based on various standards such as IEEE 802.15.4, and may be called by various names.

The method proposed in this disclosure has been described with a focus on examples applied to 3GPP LTE/LTE-A and 5G systems, but it can be applied to various wireless communication systems in addition to 3GPP LTE/LTE-A and 5G systems.

Claims (17)

A method performed by a first terminal in a wireless communication system, the method comprising: A step of receiving first configuration information related to a direct path and at least one indirect path from a base station; and A step of activating or deactivating the direct path or the at least one indirect path based on at least one measurement value acquired by the first terminal satisfying at least one condition, A method wherein the first configuration information includes first information related to whether activation or deactivation of the direct path or the at least one indirect path is permitted based on the at least one measurement value. In the first paragraph, A method according to claim 1, wherein the at least one measurement value comprises at least one of an altitude of the first terminal, a velocity of the first terminal, a cell quality value of the direct path, or a quality value associated with the at least one indirect path. In the second paragraph, At least one of the above conditions is: A first condition relating to whether the altitude of the first terminal is above or below a first threshold value; A second condition relating to whether the speed of the first terminal is greater than or less than a second threshold value; A third condition relating to whether the cell quality value of the above direct path is greater than or less than a third threshold value; or A method comprising at least one of a fourth condition relating to whether a quality value associated with at least one indirect path is greater than or less than a fourth threshold value. In the third paragraph, A method wherein each of the first threshold, the second threshold, the third threshold and the fourth threshold is set or predefined by the base station. In the first paragraph, A method wherein information related to the activation or deactivation is transmitted to the base station or the second terminal based on the activation or deactivation of the direct path or at least one indirect path. In the first paragraph, A method wherein at least one of a sidelink (SL) bandwidth part (BWP) or a SL CG (configured grant) setting on the at least one indirect path is disabled or released based on the at least one indirect path being disabled. In the first paragraph, A method wherein at least one of a semi-persistence scheduling (SPS) setting, a BWP setting, a CG setting, a sounding reference signal (SRS) setting, and a physical uplink control channel (PUCCH) setting related to the direct path is disabled or released based on the direct path being disabled. In paragraph 5, A method wherein, based on the activation of the direct path, a random access procedure related to the direct path is performed by the first terminal to transmit information related to the activation to the base station. In paragraph 5, A method wherein, based on the activation of at least one indirect path, information related to the activation is transmitted to the base station or the second terminal through the at least one indirect path. In paragraph 5, A method in which information related to the above activation or deactivation is transmitted to the base station or the second terminal through uplink control information (UCI), a medium access control (MAC) control element (CE) or a radio resource control (RRC) message. In the first paragraph, A method wherein the first configuration information includes second information related to whether the direct path and the at least one indirect path are initially activated. In paragraph 5, A method wherein the first terminal is a remote terminal and the second terminal is a relay terminal. In a first terminal performing communication in a wireless communication system, the first terminal: one or more transceivers; and comprising one or more processors coupled to said one or more transceivers; One or more of the above processors: Receiving first configuration information related to a direct path and at least one indirect path from a base station via said one or more transceivers; and Based on at least one measurement value acquired by the first terminal satisfying at least one condition, the direct path or the at least one indirect path is set to be activated or deactivated, A first terminal, wherein the first configuration information includes first information related to whether activation or deactivation of the direct path or the at least one indirect path is permitted based on the at least one measurement value. A method performed by a base station in a wireless communication system, the method comprising: A step of transmitting first configuration information related to a direct path and at least one indirect path to a first terminal; and A step of receiving information about activation or deactivation of the direct path or the at least one indirect path from the first terminal based on at least one measurement value acquired by the first terminal satisfying at least one condition, A method wherein the first configuration information includes first information related to whether activation or deactivation of the direct path or the at least one indirect path is permitted based on the at least one measurement value. In a base station performing communication in a wireless communication system, the base station: one or more transceivers; and comprising one or more processors coupled to said one or more transceivers; One or more of the above processors: Transmitting first configuration information related to a direct path and at least one indirect path to a first terminal via said one or more transceivers; and Based on at least one measurement value acquired by the first terminal satisfying at least one condition, information on activation or deactivation of the direct path or the at least one indirect path is set to be received from the first terminal through the one or more transceivers, A base station, wherein the first configuration information includes first information related to whether activation or deactivation of the direct path or the at least one indirect path is permitted based on the at least one measurement value. A processing device configured to control a first terminal to perform communication in a wireless communication system, the processing device comprising: one or more processors; and One or more computer memories operatively connected to said one or more processors and storing instructions that perform operations based on execution by said one or more processors, The above actions are: An operation of receiving first configuration information related to a direct path and at least one indirect path from a base station; and An operation of activating or deactivating the direct path or the at least one indirect path based on at least one measurement value acquired by the first terminal satisfying at least one condition, A processing device, wherein the first configuration information includes first information related to whether activation or deactivation of the direct path or the at least one indirect path is permitted based on the at least one measurement value. One or more non-transitory computer-readable media storing one or more instructions, The above one or more commands are executed by one or more processors, so that the device performing communication in a wireless communication system: Receiving first configuration information related to a direct path and at least one indirect path from a base station; and Based on at least one measurement value acquired by said device satisfying at least one condition, said direct path or said at least one indirect path is controlled to be activated or deactivated, A computer-readable medium, wherein the first configuration information includes first information related to whether activation or deactivation of the direct path or the at least one indirect path is permitted based on the at least one measurement value.

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