COMMUNICATION DEVICE AND SCHEDULING NODE APPLYING RECONFIGURATION OF NETWORK-CONTROLLED REPEATER - Patent application

Abstract

A communications device, a scheduling node, and a communications method for the communications device and the scheduling node are provided. The communications device includes a transceiver unit that, in operation, receives control signaling indicating a relay transmission configuration and circuitry that, in operation, determines whether a radio link is operational. If the circuitry determines that the radio link is operational, the transceiver unit, in operation, receives a signal to be relayed using the relay transmission configuration and transmits the received signal. If the circuitry determines that a radio link failure has occurred, the circuitry, in operation, performs radio link recovery, and the transceiver unit, in operation, receives the signal to be relayed using the relay transmission configuration after the radio link recovery has successfully completed, and transmits the received signal.

Description

[Technical Field]

[0001] This disclosure relates to the transmission and reception of signals in communication systems, such as 3GPP® communication systems. In particular, this disclosure relates to methods and apparatus for such transmission and reception. [Background technology]

[0002] The 3rd Generation Partnership Project (3GPP) is working on technical specifications for next-generation cellular technology (also known as 5G), including New Radio (NR) access technology (RAT) operating in the frequency range up to 100 GHz. NR is the successor to technologies represented by Long Term Evolution (LTE) and LTE Advanced (LTE-A).

[0003] In systems such as LTE and NR, further improvements and options may facilitate efficient operation of the communication system and certain devices associated with the communication system. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 v15.6.0 [Non-patent document 2] 3GPP TS 38.211 [Non-patent document 3] ITU-R M.2083 [Non-patent document 4] 3GPP TR 38.913 [Non-Patent Document 5] 3GPP TS 23.501 v16.1.0 [Non-patent document 6] 3GPP TS 38.212 v15.6.0 [Non-Patent Document 7] “New SI: Study on NR Smart Repeaters,” 3GPP RP-213562, RAN#94e, December 2021 [Non-patent document 8] 3GPP TS 36.106 [Non-Patent Document 9] "Revised WID on NR network-controlled repeaters" (RP-22350, 3GPP TSG RAN Meeting #98-e, December 2022) [Non-Patent Document 10] 3GPP TR 38.867 [Non-Patent Document 11] 3GPP TR 38.867 [Non-Patent Document 12] 3GPP TS 36.106 17.0.0 version [Non-Patent Document 13] C. Johnson, 5G New Radio in Bullets, 1st edition Summary of the Invention

[0005] The non-limiting and exemplary embodiments contribute to efficient operation of relay nodes, and in particular to reducing signaling overhead associated with reconfiguration of communication devices that include relay nodes.

[0006] In one embodiment, the disclosed technology features an apparatus (e.g., a communications apparatus, particularly a relay apparatus). The apparatus includes a transceiver that, in operation, receives control signaling indicating a relay transmission configuration and a circuit that, in operation, determines whether a wireless link is operational. If the circuit determines that the wireless link is operational, the transceiver is operative to receive a signal to be relayed using the relay transmission configuration and transmit the received signal. If the circuit determines that a wireless link failure has occurred, the circuit is operative to perform wireless link recovery, and the transceiver is operative to receive the signal to be relayed using the relay transmission configuration and transmit the received signal after the wireless link recovery has successfully completed.

[0007] It should be noted that the general or specific embodiments may be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any combination thereof.

[0008] Further advantages and benefits of the disclosed embodiments and various implementations will become apparent from the specification and drawings. Such advantages and / or benefits may be obtained individually by the various embodiments and features described in the specification and drawings, and it is not necessary for all of them to be present in order to obtain one or more of such advantages and / or benefits. [Brief explanation of the drawings]

[0009] Exemplary embodiments will now be described in more detail with reference to the accompanying drawings. [Figure 1] FIG. 1 illustrates an example architecture of a 3GPP NR system. [Figure 2] Schematic diagram showing functional separation between NG-RAN and 5GC [Figure 3] Sequence diagram of RRC connection establishment / reconfiguration procedure [Figure 4]Schematic diagram showing the usage scenarios for enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC) [Figure 5] Block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario [Figure 6] A block diagram illustrating the functional communication structure of a relay node in a communication system in which the node relays signals between a base station and a UE. [Figure 7A] Diagram showing relay transmission setup before radio link recovery [Figure 7B] Diagram showing relay transmission setup after radio link recovery [Figure 8] Block diagram of a communication device and a scheduling node [Figure 9] Block diagram showing the circuitry of a communication device [Figure 10] 1 is a flowchart illustrating steps of a communication method for a communication device; [Figure 11] 1 is a flowchart illustrating steps of a scheduling node communication method. [Figure 12A] Diagram showing relay transmission setup before radio link recovery [Figure 12B] Diagram showing relay transmission setup after radio link recovery [Figure 13] 1 is a flowchart illustrating steps of a communication method for a communication device. [Figure 14] FIG. 1 illustrates time thresholds for radio link recovery. [Figure 15] Figure showing how to cancel relay transmission settings [Figure 16] Block diagram showing the circuitry of the scheduling node [Figure 17] 1 is a flowchart illustrating steps of a scheduling node communication method. DETAILED DESCRIPTION OF THE INVENTION

[0010] <5G NR system architecture and protocol stack> 3GPP is working on the next release of fifth-generation cellular technology (known simply as "5G"), which includes the development of New Radio Access Technology (NR), which will operate in frequencies up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, allowing for the testing and commercial deployment of smartphones compliant with the 5G NR standard.

[0011] In particular, the overall system architecture assumes an NG-RAN (Next Generation Radio Access Network) with gNBs, which provide termination of NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols for UEs. The gNBs are interconnected with each other via an Xn interface. The gNBs are also connected to an NGC (Next Generation Core) via a Next Generation (NG) interface, more specifically to an AMF (Access and Mobility Management Function) (e.g., a specific core entity that runs the AMF) via an NG-C interface, and to a UPF (User Plane Function) (e.g., a specific core entity that runs the UPF) via an NG-U interface. The NG-RAN architecture is shown in Figure 1 (see, for example, Non-Patent Document 1, Section 4).

[0012] The user plane protocol stack in NR (see, for example, 3GPP TS 36.100, Section 4.4.1) includes the PDCP (Packet Data Convergence Protocol) sublayer, the RLC (Radio Link Control) sublayer, and the MAC (Medium Access Control) sublayer, which are terminated at the gNB on the network side. In addition, a new access stratum (AS) sublayer (SDAP, Service Data Adaptation Protocol) is introduced on top of PDCP (see, for example, 3GPP TS 36.100, Section 6.5). A control plane protocol stack is also defined for NR (see, for example, 3GPP TS 36.100, Section 4.4.2). An overview of Layer 2 functions is provided in 3GPP TS 36.100, Section 6. The functions of the PDCP, RLC, and MAC sublayers are described in 3GPP TS 26.25.0, Section 6.4, Section 6.3, and Section 6.2, respectively. The functions of the RRC layer are described in 3GPP TS 26.25.0, Section 7.

[0013] For example, the Medium-Access-Control (MAC) layer handles multiplexing of logical channels, including handling various numerologies, as well as scheduling and scheduling-related functions.

[0014] The physical layer (PHY) is responsible for, for example, coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. The physical layer also handles mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmitting a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels are the PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel) for the uplink, and the PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel) for the downlink.

[0015] NR use cases / deployment scenarios include enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine-type communications (mMTC), which have diverse requirements for data rates, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps downlink and 10 Gbps uplink) and user-perceived data rates approximately three times higher than those offered by IMT-Advanced. In contrast, URLLC has more stringent requirements, including extremely low latency (user plane latency of 0.5 ms for both UL and DL) and high reliability (1-10 Mbps within 1 ms). -5) and mMTC requires high connection density (1 km in urban environments). 2 1,000,000 devices per second), wide coverage in harsh environments, and extremely long battery life (15 years) to lower device costs may preferably be required.

[0016] Therefore, an OFDM numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not work well for another use case. For example, low-latency services may preferably require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also referred to as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with small delay spreads. To maintain a similar CP overhead, the subcarrier spacing should be optimized depending on the delay spread. In NR, two or more values ​​of subcarrier spacing may be supported. Therefore, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, etc. are currently being considered. The symbol length T u and the subcarrier spacing Δf is given by the formula (Δf=1 / T u ) As in LTE systems, the term "resource element" can be used to denote the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0017] In the new radio system 5G-NR, for each numerology and carrier, a resource grid consisting of subcarriers and OFDM symbols is defined for both the uplink and the downlink. Each element within the resource grid is called a resource element and is identified based on a frequency index in the frequency domain and a symbol position in the time domain (see Non-Patent Document 2, v15.6.0, or, for example, v16.2.0, Section 4). For example, downlink transmission and uplink transmission are organized into frames with a duration of 10 ms, and each frame is composed of 10 subframes with a duration of 1 ms each. In the implementation of 5G NR, the number of consecutive OFDM symbols per subframe depends on the subcarrier spacing setting. For example, in the case of a 15 kHz subcarrier spacing, one subframe has 14 OFDM symbols (similar to an LTE-compliant implementation assuming a normal cyclic prefix). On the other hand, in the case of a 30 kHz subcarrier spacing, one subframe has two slots, and each slot contains 14 OFDM symbols.

[0018] NR supports multiple different types of subcarrier spacings labeled by the parameter μ compared to the numerology (subcarrier spacing and symbol length) of LTE (in LTE, only a 15 kHz subcarrier spacing, which corresponds to μ = 0 in NR). The types of NR numerology are summarized in Non-Patent Document 2, v15.7.0.

[0019] <5G NR Functional Separation between NG-RAN and 5GC> Figure 2 shows the functional separation between NG-RAN and NGC or 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. The logical nodes of 5GC are AMF, UPF, and SMF.

[0020] In particular, gNB and ng-eNB handle the following main functions: - Radio Resource Management functions, such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, and dynamic resource allocation (scheduling) to UEs in both uplink and downlink directions. - IP header compression, encryption, and integrity protection of data - AMF selection at UE attach time when routing to an AMF cannot be determined from information provided by the UE - Routing of user plane data to the UPF - Routing control plane information to AMF - Establishing and terminating connections - Scheduling and sending paging messages - Scheduling and transmission of system broadcast information (sent from AMF or OAM) - Configuring measurements and measurement reporting for mobility and scheduling - Transport-level packet marking in the uplink - Session Management - Network slicing support - QoS flow management and mapping to data radio bearers - Support for UEs in RRC_INACTIVE state - NAS message delivery function - Wireless Access Network Sharing - Dual Connectivity - Tight interworking between NR and E-UTRA

[0021] The Access and Mobility Management Function (AMF) handles the following main functions: - Termination of Non-Access Stratum (NAS) signaling - NAS signaling security - Access Stratum (AS) security control - Core Network (CN) inter-node signaling for mobility between 3GPP access networks - Reachability for idle mode UEs (including control and execution of paging retransmissions) - Registration Area Management - Support for intra-system and inter-system mobility - Access Authentication - Access authentication, including roaming rights checks - Mobility management controls (subscriptions and policies) - Network slicing support - Selection of Session Management Function (SMF)

[0022] Additionally, the User Plane Function (UPF) handles the following main functions: - Anchor points for intra-RAT / inter-RAT mobility (when applicable) - External PDU session points for interconnection with data networks - Packet routing and forwarding - User plane part of packet inspection and policy rule enforcement - Traffic usage reports - an uplink classifier to support routing of traffic flows to the data network; - Branching points to support multi-homed PDU sessions - User plane QoS processing (e.g., packet filtering, gating, UL / DL rate enforcement) - Verification of uplink traffic (mapping from SDF to QoS flow) - Downlink packet buffering and triggering of downlink data notification

[0023] Finally, the Session Management Function (SMF) processes the following main functions: - Session management - Allocation and management of UE IP addresses - Selection and control of the UP function - Configuration of traffic steering in the User Plane Function (UPF) to route traffic to the correct destination - Policy enforcement and QoS control part - Downlink data notification

[0024] <Procedures for establishment and reconfiguration of RRC connection> Figure 3 shows the interaction between the UE, gNB, and AMF (5GC entity) in the NAS part when the UE transitions from RRC_IDLE to RRC_CONNECTED (see, for example, Non-Patent Document 1).

[0025] RRC is a higher layer signaling protocol used to configure the UE and the gNB. Specifically, in this transition, the AMF creates UE context data (including, for example, PDU session context, security keys, UE radio capabilities, and UE security capabilities) and sends it to the gNB via an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security with the UE by sending a SecurityModeCommand message to the UE, and the UE responds with a SecurityModeComplete message. The gNB then performs reconfiguration to establish signaling radio bearer 2 (SRB2) and data radio bearers (DRBs) by sending an RRCReconfiguration message to the UE and receiving an RRCReconfigurationComplete message from the UE in response. In the case of a signaling-only connection, these steps related to RRCReconfiguration are skipped because SRB2 and DRBs are not established. Finally, the gNB notifies the AMF that the establishment procedure is complete via an INITIAL CONTEXT SETUP RESPONSE.

[0026] Thus, the present disclosure provides a fifth-generation core (5GC) entity (e.g., AMF, SMF, etc.) having a control circuit that, in operation, establishes a next-generation (NG) connection with a gNodeB such that a signaling radio bearer is established between the gNodeB and a user equipment (UE), and a transmitter that, in operation, transmits an initial context setup message to the gNodeB over the NG connection. In particular, the gNodeB transmits radio resource control (RRC) signaling including a resource allocation configuration information element to the UE over the signaling radio bearer. The UE then performs uplink transmission or downlink reception based on the resource allocation configuration.

[0027] <IMT usage scenarios after 2020> Figure 4 shows some use cases for 5G NR. The 3GPP NR (3rd Generation Partnership Project New Radio) is considering three use cases that are expected to support a wide variety of services and applications with IMT-2020. The first phase of specifications for enhanced mobile broadband (eMBB) has been completed. Current and future work includes standardization for ultra-reliable and low-latency communications (URLLC) and large-scale machine-type communications, in addition to further extending eMBB support. Figure 4 shows some example IMT usage scenarios expected beyond 2020 (see, for example, Figure 2 in Non-Patent Document 3).

[0028] URLLC use cases have stringent requirements for capabilities such as throughput, latency, and availability, and are envisioned as one of the means to realize future vertical applications, such as wireless control of industrial manufacturing or production processes, remote medical surgery, power distribution automation in smart grids, and transportation safety. URLLC's ultra-high reliability is supported by identifying technologies to meet the requirements set by [Non-Patent Document 4]. For NR URLLC in Release 15, key requirements include a user plane target latency of 0.5 ms for the uplink (UL) and 0.5 ms for the downlink (DL). A typical URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size with a user plane latency of 1 ms.

[0029] From a physical layer perspective, there are several ways to improve reliability. Current scope for reliability improvement includes defining a separate CQI table for URLLC, a more compact DCI format, PDCCH repetition, etc. However, as NR becomes more stable and developed (a key requirement for NR URLLC), the scope for achieving ultra-high reliability may increase. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0030] Furthermore, technology enhancements targeted at NR URLLC target latency improvement and reliability enhancement. Technology enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition of data channels, and downlink preemption. Preemption means that a transmission for which resources have already been allocated is aborted and the already allocated resources are used for another transmission requested later with smaller latency / higher priority requirements. Thus, an already granted transmission is preempted by a later transmission. Preemption applies regardless of the specific service type. For example, a transmission of service type A (URLLC) can be preempted by a transmission of service type B (e.g., eMBB). Technology enhancements for reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0031] The mMTC (Massive Machine Type Communication) use case is characterized by a very large number of connected devices transmitting relatively small amounts of data that are generally latency sensitive. The devices need to be low cost and have extremely long battery life. From an NR perspective, utilizing very narrow bandwidth portions is one possible solution to achieve power savings from the UE perspective, enabling long battery life.

[0032] As mentioned above, it is expected that the range of reliability in NR will expand. One key requirement for all cases, especially for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can be considered to improve reliability from a radio perspective and a network perspective. In general, there are several key areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity related to the frequency, time, and / or spatial domains. These areas are generally applicable to reliability, regardless of the specific communication scenario.

[0033] For NR URLLC, further use cases with more stringent requirements have been identified, e.g., in factory automation, the transport industry, and power supply. The more stringent requirements include higher reliability (up to 10 times faster) depending on the use case. -6 level), higher availability, packet size up to 256 bytes, time synchronization on the order of a few microseconds (values ​​range from 1 to a few microseconds depending on the frequency range), and short latency on the order of 0.5 to 1 ms (target latency for the user plane in particular is 0.5 ms).

[0034] Furthermore, for NR URLLC, several technical enhancements are possible from the perspective of the physical layer. In particular, enhancements related to the PDCCH (Physical Downlink Control Channel) include compact DCI, repetition of the PDCCH, and increased PDCCH monitoring. Also, enhancements related to UCI (Uplink Control Information) include enhancements of HARQ (Hybrid Automatic Repeat Request) and CSI feedback. In addition, enhancements of the PUSCH related to mini-slot level hopping and retransmission / repetition have also been recognized. The term "mini-slot" means a transmission time interval (TTI: Transmission Time Interval) that contains a smaller number of symbols than a slot (a slot contains, for example, 14 symbols).

[0035] <QoS Control> The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, the QoS flow is the finest granularity for QoS differentiation in a PDU session. The QoS flow is identified within the PDU session by a QoS flow ID (QFI) that is transmitted in the encapsulation header through the NG-U interface.

[0036] The 5GC establishes one or more PDU sessions for each UE. The NG-RAN establishes at least one Data Radio Bearer (DRB) for each UE along with the PDU session, and can then configure additional DRBs for the QoS flows of that PDU session (as determined by the NG-RAN, e.g., as described above with reference to Figure 3). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, and AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0037] Figure 5 shows the 5G NR non-roaming reference architecture (see 3GPP TS 36549-1, Section 4.23). Application Functions (AFs) (e.g., external application servers handling 5G services, as exemplarily illustrated in Figure 4) interact with the 3GPP Core Network to provide services. For example, they support application influence on traffic routing, access Network Exposure Functions (NEFs), or interact with a policy framework (see Policy Control Function (PCF)) for policy control (e.g., QoS control). Based on the operator's deployment, application functions deemed trusted by the operator can be allowed to interact directly with the relevant Network Functions. Application Functions not permitted by the operator to directly access Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0038] Figure 5 shows further functional units of the 5G architecture: Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN) (e.g., operator services, internet access, or third-party services). All or part of the core network functions and application services may be located and run in a cloud computing environment.

[0039] Therefore, the present disclosure provides an application server (e.g., an AF in a 5G architecture) having: a transmitter unit that, in operation, sends a request including QoS requirements for at least one of a URLLC service, an eMMB service, and an mMTC service to at least one of 5GC functions (e.g., an NEF, an AMF, an SMF, a PCF, an UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE in accordance with the QoS requirements; and a control circuit that, in operation, executes the service using the established PDU session.

[0040] <Control signal> In the present disclosure, the downlink control signal (information) according to the present disclosure may be a signal (information) transmitted via a PDCCH of a physical layer, or may be a signal (information) transmitted via a MAC Control Element (CE) of a higher layer or an RRC. The downlink control signal may be a predefined signal (information).

[0041] The uplink control signal (information) according to the present disclosure may be a signal (information) transmitted via a PUCCH of a physical layer, or may be a signal (information) transmitted via a MAC CE of a higher layer or RRC. The uplink control signal may also be a predefined signal (information). The uplink control signal may be uplink control information (UCI), first-stage sidelink control information (SCI), or second-stage SCI.

[0042] <Uplink / Downlink / Sidelink> The present disclosure may be applied to any of the uplink, downlink, and sidelink.

[0043] For example, the present disclosure may be applied to the uplink PUSCH, PUCCH, and PRACH, the downlink PDSCH, PDCCH, and PBCH, and the sidelink PSSCH (Physical Sidelink Shared Channel), PSCCH (Physical Sidelink Control Channel), and PSBCH (Physical Sidelink Broadcast Channel).

[0044] The PDCCH, PDSCH, PUSCH, and PUCCH are examples of a downlink control channel, a downlink data channel, an uplink data channel, and an uplink control channel, respectively. The PSCCH and PSSCH are examples of a sidelink control channel and a sidelink data channel, respectively. The PBCH and PSBCH are examples of a broadcast channel, and the PRACH is an example of a random access channel.

[0045] <Data channel / control channel> The present disclosure may be applied to both data channels and control channels. The channels in this disclosure may be replaced with data channels including PDSCH, PUSCH, and PSSCH, and / or control channels including PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0046] <Reference signal> In the present disclosure, a reference signal is a signal known to both a base station and a mobile station, and each reference signal may be referred to as a reference signal (RS) or a pilot signal. A reference signal may be any of a Demodulation Reference Signal (DMRS), a Channel State Information Reference Signal (CSI-RS), a Tracking Reference Signal (TRS), a Phase Tracking Reference Signal (PTRS), a Cell-specific Reference Signal (CRS), and a Sounding Reference Signal (SRS). A reference signal may be used for channel characteristic estimation and / or synchronization in a receiving device. One or more parameters of a reference signal may be used for transmitting data (control, payload), and one or more other parameters of the same reference signal may be used as a reference. For example, a reference signal may be used to compare a reference power with a received power. However, a reference signal may also be used for comparing phase and / or frequency, etc.

[0047] <time interval> In the present disclosure, the time resource unit is not limited to one or a combination of a slot and a symbol, and may be a time resource unit such as a frame, a superframe, a subframe, a slot, a subslot of a time slot, a minislot, or a symbol, an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier-Frequency Division Multiplexing Access (SC-FDMA) symbol, or other time resource unit. The number of symbols included in one slot is not limited to the number of symbols exemplified in the above-mentioned embodiment, and may be other numbers of symbols.

[0048] <Frequency band> The present disclosure may be applied to both licensed and unlicensed bands. While applicable to either frequency band, it may be particularly advantageous for high frequency bands because the benefits of beamforming are greater in higher frequency bands. In particular, the frequency band for 5G NR is divided into two different frequency ranges. First, FR1 (Frequency Range 1), which includes frequency bands below 6 GHz that were partially used in previous standards, has been expanded to potentially cover new spectrum offerings from 410 MHz to 7125 MHz. The other band is FR2 (Frequency Range 2), which includes the frequency band from 24.25 GHz to 52.6 GHz.

[0049] <Communication> The present disclosure may be applied to communication between a base station and a terminal (Uu link communication), communication between terminals (sidelink communication), and V2X (Vehicle to Everything) communication. The channels in the present disclosure may be rephrased as PSCCH, PSSCH, physical sidelink feedback channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0050] The present disclosure can be applied to both terrestrial networks and non-terrestrial networks (NTNs) using satellites or high altitude pseudo satellites (HAPSs). The present disclosure can also be applied to networks with large cell sizes and terrestrial networks with large delays compared to the symbol length or slot length, such as ultra-wideband transmission networks.

[0051] <Antenna port> An antenna port refers to a logical antenna (antenna group) formed from one or more physical antennas. That is, an antenna port does not necessarily refer to a single physical antenna, but may refer to an array antenna consisting of multiple antennas. For example, the number of physical antennas constituting an antenna port is not defined. Instead, an antenna port is defined as the smallest unit through which a terminal is permitted to transmit a reference signal. An antenna port may also be defined as the smallest unit for multiplication of precoding vector weights.

[0052] <Downlink control channel monitoring, PDCCH, DCI> Many of the functions performed by a UE involve monitoring a downlink control channel (eg, PDCCH, see 3GPP TS 26.210, section 5.2.3) to receive, for example, specific control information or data intended for the UE.

[0053] Below is a non-exhaustive list of such features: - Paging message monitoring function, - System information acquisition function, - signaling supervision operation in discontinuous reception (DRX) functionality; - inactivity monitoring behavior in the discontinuous reception (DRX) function; - receiving a random access response in a random access function; - Packet Data Convergence Protocol (PDCP) layer reordering function

[0054] As described above, the PDCCH is monitored by the UE to identify and receive information intended for the UE, such as control information and user traffic (e.g., DCI on the PDCCH, user data on the PDSCH indicated by the PDCCH).

[0055] The control information in the downlink (which can be called Downlink Control Information, DCI) has the same purpose in 5G NR as DCI in LTE, i.e. it is a set of special control information for scheduling, for example, a downlink data channel (e.g., PDSCH) or an uplink data channel (e.g., PUSCH). Many different DCI formats have already been defined for 5G NR (see 3GPP TS 26.110, Section 7.3.1).

[0056] These DCI formats represent the predetermined formats that the respective information is formed and transmitted in. In particular, DCI formats 0_1 and 1_1 are used for scheduling the PUSCH and PDSCH in one cell, respectively.

[0057] The PDCCH monitoring in each of these functions serves a specific purpose and is therefore initiated for that purpose. PDCCH monitoring is typically controlled at least based on a timer operated by the UE. The timer has the purpose of controlling PDCCH monitoring, for example, to limit the maximum length of time that the UE monitors the PDCCH. For example, the UE does not need to monitor the PDCCH indefinitely and can stop monitoring after a certain time to conserve power.

[0058] As mentioned above, one of the purposes of the DCI in the PDCCH is to dynamically schedule resources in the downlink, uplink, or sidelink. In particular, several formats of the DCI are provided to convey notification of resources allocated to a data channel for a particular user (resource allocation, RA). The resource allocation may include specifying resources in the frequency domain and / or the time domain.

[0059] <Physical resource block> In general, the term "Physical Resource Block" (PRB) refers to the smallest allocable resource unit available for the transmission of (user) data. In LTE and NR, a PRB has a predetermined number of consecutive subcarriers in the frequency domain (e.g., 12) and a predetermined number of symbols in the time domain (e.g., 14 OFDM symbols in LTE).

[0060] <Technical terms> The following describes UEs, relay nodes, base stations (network nodes), and procedures for new radio access technologies envisioned for 5G mobile communication systems, but these may also be used in LTE mobile communication systems or future mobile communication systems. Several different implementations and variations are also described. The following disclosure is facilitated by, and may be based, for example, at least in part on, the above-mentioned discussions and findings.

[0061] In general, it should be noted that many assumptions have been made herein to enable the principles underlying the present disclosure to be explained in a clear, concise, and understandable manner. However, it should be understood that these assumptions are merely exemplary for purposes of explanation herein, and are not necessarily required for the present disclosure, and therefore do not limit the scope of the disclosure. Those skilled in the art will understand that the principles described in the following disclosure and claims can be applied to different scenarios and in ways not explicitly described herein.

[0062] Furthermore, although specific terminology used in the context of new radio access technologies for upcoming communication systems has not yet been fully determined or may ultimately change, some of the terms used below, such as procedures, entities, and layers, are closely related to the terms used in LTE / LTE-A systems or in the current 3GPP 5G standardization. Therefore, the terminology may change in the future without affecting the functionality of the embodiments. Therefore, those skilled in the art will recognize that the embodiments and their scope of protection are not limited to the specific terminology illustratively used herein due to the absence of newer or ultimately agreed-upon terminology, but should be understood more broadly in terms of the functions and concepts underlying the functions and principles of the present disclosure.

[0063] <terminal> In LTE and NR, a terminal, user terminal, user device, mobile station, or mobile node is called user equipment (UE). It may be a mobile device or communication device with user equipment functionality, such as a wireless telephone, smartphone, tablet computer, or USB (Universal Serial Bus) stick. However, the term mobile device is not limited thereto. In general, a relay may also have such mobile device functionality or function as a relay. For example, a terminal is a physical entity (physical node) in a communication network. Furthermore, a communication device may be any machine-type communication device, such as an IoT device. A node may have several functional entities. A functional entity refers to a software or hardware module that realizes and / or provides a set of predetermined functions to other functional entities of the same or other nodes or networks. A node may have one or more interfaces that connect the node to communication facilities or media over which the node can communicate. Similarly, a network entity may have logical interfaces that connect functional entities to communication facilities or media over which it can communicate with other functional entities or correspondent nodes.

[0064] <Base station> In this disclosure, a base station may be, for example, a Transmission Reception Point (TRP), a cluster head, an access point, a Remote Radio Head (RRH), an eNodeB (eNB), a gNodeB (gNB), a Base Station (BS), a Base Transceiver Station (BTS), a base unit, or a gateway. Also, in sidelink communication, a terminal may be used instead of a base station. A base station may be a relay device that relays communication between an upper node and a terminal. A base station may be a roadside unit. A base station may be, for example, a scheduling node or a network node that forms part of a network for providing services to terminals. In particular, a base station may provide wireless access to terminals. Communication between a communication device (e.g., a UE, i.e., a terminal) and a scheduling device (e.g., a base station) is usually standardized and may be defined by different layers, such as PHY, MAC, and RRC (see also the discussion above). In LTE and NR, the air interface protocol stack includes a physical layer, a medium access (MAC) layer, and upper layers. The control plane is provided with a higher layer protocol, the Radio Resource Control Protocol. Through RRC, base stations can control the configuration of terminals, and terminals can communicate with base stations to perform control tasks such as establishing and modifying connections and bearers, measurements, and other functions. The terminology used in LTE is eNB (or eNodeB), while the terminology currently used in 5G NR is gNB. The term "base station" or "radio base station" as used herein refers to a physical entity in a communication network. A base station, like a mobile station, can have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a predetermined set of functions to other functional entities of the same or other nodes or networks. The physical entity performs several control tasks related to communication devices, including one or more of scheduling and configuration.It should be noted that the functions of the base station and the communication device may be integrated into one device. For example, a mobile terminal may also perform the functions of a base station for another terminal. The terminology used in LTE is eNB (or eNodeB), while the terminology currently used in 5G NR is gNB. In particular, the base station may be a gNB in ​​a Non-Terrestrial Network (NTN) NR system.

[0065] <Relay node> The term "repeater" or "relay node" refers to a general node or any communication device (in a communication system) used to receive a signal from one entity, amplify the signal, and transmit it to another entity.

[0066] In other words, a relay may be any device controlled by a first entity (hereinafter generally referred to as a base station / scheduling device / scheduling node / gNB) to relay signals between the first entity and a second entity (hereinafter generally referred to as a UE). Although a relay in this disclosure is described as amplifying signals between a base station (network node, scheduling device) and a user equipment, a relay in this disclosure may also be used to amplify signals between two user equipments, for example. In particular, a relay may be a UE, a base station (e.g., a gNB), an NCR, or an IAB (Integrated Access Backhaul).

[0067] For example, a relay may be an RF (radio frequency) repeater that simply receives, amplifies, and retransmits a signal without performing baseband L1 processing such as (H)ARQ demodulation and decoding. However, the present disclosure is not limited thereto, and a relay may be a smart repeater that performs demodulation, decoding, and / or error correction on the signal before relaying. In particular, a signal that a relay receives from an entity and relays to another entity and a corresponding signal that the relay transmits to the other entity may be identical (up to the amplification process) or may differ (e.g., by modulation and, e.g., by error correction). Note that in this disclosure, (i) a signal / transmission that a relay receives from an entity for relaying to another entity is also referred to as a “relayed signal / transmission,” and (ii) a signal / transmission of a relay node that a relay relays a relayed signal / transmission is also referred to as a “relayed signal / transmission.” In general, a relayed transmission may be (i) received from a gNB or (ii) received from another entity and relayed to a gNB. Also, a relay transmission may be (i) a transmission transmitted to a gNB or (ii) a transmission transmitted to another entity. Furthermore, it should be noted that the present disclosure is applicable to relays regardless of the layer (RF, L1, L2, L3, etc.) of the relay, the applicable frequency band, the multiplexing domain, etc.

[0068] In general, a relay node serves to extend coverage within a cell and / or improve performance at the cell edge, while enabling cost reduction compared to increasing the number of base stations (network nodes). In the downlink, the relay node may receive, amplify, and further transmit, for example, to one or more terminals, signals from a network node (e.g., a scheduling device or a base station) in the downlink. In the uplink, the relay node may receive, amplify, and further transmit, for example, signals from one or more terminals to a network node (e.g., a base station). To this end, the relay node may have multiple radio access interfaces, in particular the following radio access interfaces:

[0069] - Interface for wireless access to the UE (also called access link) - the interface for wireless access to the base station (also known as the backhaul link), and / or - An interface for transmitting and / or receiving control information to and from the base station (also called C-link)

[0070] A relay node can conceptually be implemented at any layer (e.g., RF, L1, L2, or L3), however, for efficiency and cost reasons, a simpler physical layer repeater may be desirable.

[0071] Relaying in LTE was not cost-effective because it differed from simply using a repeater to rebroadcast a signal (as an RF repeater does). For example, in LTE, an L2 repeater demodulates and decodes the received data, performs any error correction, and then retransmits it as a new signal. This avoids the degradation of the signal-to-noise ratio that would result from using a repeater; rather, an LTE repeater could improve signal quality. With an LTE repeater, a UE communicates with a relay node, which then communicates with a "donor" eNB. The links between the UE and the repeater and between the repeater and the BS could be time-division multiplexed or frequency-multiplexed. Several other repeater options were available, but none supported beamforming. The LTE repeater concept has not been widely adopted.

[0072] 3GPP recently defined a study item and work item on Network-Controlled Repeaters (NCRs) in NR Release 18 (Non-Patent Document 7, freely available at www.3gpp.org), which allows repeaters to extend the coverage of the network and are expected to be more cost-effective than the Integrated Access and Backhaul (IAB) introduced in Rel. 16.

[0073] One of the desirable features of a network-controlled repeater is the ability to perform beamforming. LTE repeaters were designed to operate in the sub-3 GHz band, where beamforming is not required (Non-Patent Document 8). This is one of the main differences between a network-controlled repeater and an LTE repeater. A network-controlled repeater should support both outdoor and indoor scenarios.

[0074] The goals of the work item on network-controlled repeaters, Non-Patent Document 9 (freely available at 3gpp.org), follow the recommendations of the specification: Non-Patent Document 10, and include the following features: The network-controlled repeater is an in-band RF repeater used to extend network coverage in the FR1 and FR2 bands. The repeater should be a single-hop, fixed smart repeater that is transparent to the UE. In other words, the signal path should be "gNB → sRelay → UE" or "UE → sRelay → gNB" only ("sRelay" in this specification refers to a smart relay, smart repeater, or network-controlled repeater, which are used interchangeably in each instance). The network-controlled repeater is required to be able to simultaneously maintain gNB-to-repeater and repeater-to-UE links. Cost efficiency should also be considered.

[0075] One concept that may need to be considered is identifying what side (control) information is necessary or desirable for the smart repeater to control the radio portion of the NCR, i.e., NCR-Fwd. Side information may include beamforming information, timing information for aligning transmit and receive boundaries, information about uplink and downlink TDD configuration and operation, ON-OFF information for efficient interference management and improved energy efficiency, and power control information for interference management. ON-OFF information indicates which instances should be relayed. Power control adjusts the transmit power of the relays in each instance.

[0076] Furthermore, control plane signaling and procedures need to be specified, narrowed down from the options described in Section 7.2 of NR Network-Controlled Repeaters, V18.0.0, September 2022, freely available at 3gpp.org. Regarding signaling configuration, the NCR-MT can obtain the necessary configuration to receive L1 / L2 signaling of side control information. The necessary configuration can be provided by RRC, provided by Operations Administration and Maintenance (OAM), hard-coded, or partially configured by RRC and partially configured or hard-coded by OAM.

[0077] The configuration obtained from RRC and / or OAM (or hard-coded) may include configuration of PHY channels carrying L1 / L2 signaling, including configuration for receiving PDCCH and PDSCH, and, if necessary, configuration for transmitting PUCCH and / or PUSCH. The configuration obtained from RRC and / or OAM (or hard-coded) may further include configuration of L1 / L2 signaling, including configuration of DCI and, if necessary, configuration of UCI (Uplink Control Information) and / or MAC CE (MAC Control Element). Parameters in the configuration required for L1 / L2 signaling may be based on existing parameters of PDCCH, PDSCH, PUCCH, PUSCH, DCI, UCI, and MAC CE, for example, parameters in Release 17.

[0078] As mentioned above, LTE also allows for the use of amplify-and-forward (AF) repeaters (RF repeaters). Such repeaters are transparent to the system and simply amplify and forward the received signal to the user. The repeaters themselves cannot determine whether the amplified signal is the desired signal received from the UE / gNB or simply interference or noise. Therefore, if the repeaters are not properly configured or deployed, they can increase inference in the system. LTE RF repeaters are designed to operate in the sub-3 GHz band, where beamforming is not required (see Non-Patent Document 12, “Evolved Universal Terrestrial Radio Access (E-UTRA); FDD repeater radio transmission and reception” (freely available at www.3gpp.org)). However, the network-controlled repeaters considered for Rel. 18 operate in both FR1 and FR2 bands and enable beamforming. Therefore, their design requires additional consideration.

[0079] 6 shows an exemplary design of a communication system 600 including a relay 650, which may be a network-controlled repeater (NCR) currently envisioned in NR. The relay 650 includes, as functional units, a mobile termination unit 640 (also referred to as a mobile terminal or MT) and a radio unit (RU) 660. The MT unit 640 may receive control signals / information from a network node (gNB) 610 and configure the RU unit 660 accordingly.

[0080] The relay 650 may transmit information to the gNB 610. Note that the MT unit 640 (which may be functionally similar to a UE) may communicate with the gNB using the channels described above (e.g., as described in the "Downlink Control Channel Monitoring, PDCCH, DCI" section, etc.). The RU unit 660 is responsible for receiving and amplifying signals (including data and / or control information) received from the gNB 610 and / or one or more (serving) UEs, such as the illustrated UE 690. In NR, the currently used term for the MT unit is NCR-MT, and the currently used term for the RU unit is NCR-Fwd (Fwd stands for forwarding).

[0081] 6, the repeater 650 includes a transmitter, illustrated as a first transceiver 630, that transmits signals / transmissions 620 toward or receives signals 620 from the gNB 610 (and possibly additional gNBs), and a second transceiver 670 that transmits signals 680 toward or receives signals 680 from one or more UEs 690. As illustrated, the transmissions / signals may be transmitted / received via beams (e.g., may be directional transmissions). However, the present disclosure is not limited in this regard.

[0082] As also shown in Figure 6, particularly in NR, the link between the gNB (i.e., the device that controls relaying) and the MT for receiving / transmitting control information is called a control link or C-link, the link between the gNB and the RU for receiving / forwarding signals is called a backhaul link, and the link between the RU and the UE for receiving / forwarding signals is called an access link.

[0083] Examples of NCR control information conveyed over the NCR control link are control signals for ON-OFF, power control, beam pattern or beam information, and TDD UL / DL configuration. Dynamic, periodic, and semi-static indication can be supported.

[0084] For TDD UL / DL configuration, flexible symbols may be supported by the NCR. For example, the gNB may dynamically or semi-statically configure the flexible slots / symbols (i.e., the gNB may send an indication to the NCR indicating dynamically or semi-statically whether the flexible symbol / slot is a DL symbol / slot or a UL symbol / slot). Both dynamic and semi-static indications may be supported. In general, the NCR may also be configured not to amplify the signal over the flexible slots / symbols.

[0085] Note that Figure 6 shows an example of a functional communication structure of a repeater. In general, there may be one transceiver unit that handles transmission and / or reception with any entity. Such a transceiver unit may include multiple antennas and amplifiers, and possibly additional circuitry to achieve signal transmission and reception. The transceiver unit may include multiple transmitters and / or receivers, thereby enabling simultaneous transmission and reception with one or more communication partners.

[0086] <Beam failure> Under normal operating conditions, a 5G NR UE can switch beams as radio conditions change over time. In particular, the UE can switch beams by reporting a CRI (CSI Reference Signal Resource Indicator) or SSBRI (SS (Synchronization Signal) / PBCH Block Resource Indicator), which provides the base station with information about the preferred beam at any given time.

[0087] However, if the radio conditions suddenly change, the UE may experience a beam failure. In an exemplary procedure for restoring the connection with minimal delay, the detection of the beam failure, the selection of a new beam, and the restoration of the connection are performed at the PHY and MAC layers without any higher layer signaling.

[0088] In particular, at the PHY layer, the quality threshold Q out_LR The failure notification to the MAC layer is triggered using the beamFailureDetectionTimer information. If the radio link quality corresponding to the monitored reference signal is worse than a threshold, the PHY layer notifies the beam failure instance. The MAC layer maintains a counter of reported beam failure instances and detects a beam failure if the beam failure instance counter exceeds a counter threshold, e.g., defined by beamFailureInstanceMaxCount, before the timer specified by beamFailureDetectionTimer information expires.

[0089] If a beam failure is detected, the UE recovers by initiating a random access procedure. Before selecting a beam for recovery, the UE measures the reference signal received power (RSRP) of candidate beams. For details about beam failure detection, see 3GPP TS 2013-01-10, Section 13.9.1.

[0090] For example, a UE or NCR detects a beam failure when the measured RSRP level of a connected beam falls below a threshold, and after a predetermined number of beam failures are detected, a beam failure recovery process using a physical random access channel (PRACH) is triggered using a candidate beam.

[0091] <Radio link failure> Under normal operating conditions, a 5G NR UE maintains connectivity to its primary serving cell and completes handovers to change the primary serving cell when necessary. If the handover procedure fails or is not initiated when needed, the UE may experience a Radio Link Failure. Possible reasons for a Radio Link Failure include congestion in the target cell, changing radio conditions, missing neighbor relations, a trigger threshold that initiates the handover procedure too late, or the inability to complete an inter-system handover (e.g., from 5G to LTE) when 5G coverage becomes weak.

[0092] In an exemplary procedure for detecting a radio link failure, the PHY layer generates Out-of-Sync and In-Sync notifications. In particular, the link quality corresponding to all monitored reference signals is checked against a quality threshold Q out An Out-of-Sync notification is generated if the signal quality of at least one monitored reference signal is worse than quality Q in If it is better than 1, an In-Sync notification is generated.

[0093] The In-Sync and Out-of-Sync notifications are forwarded to the RRC layer, where they are used in combination with timer T310 and counters N310 and N311. Timer T310 and counters N310 and N311 are configured by RRC and received in SIB1 (System Information Block 1). In particular, timer T310 is started when N310 consecutive Out-of-Sync notifications (without any In-Sync notifications in between) have been forwarded. For example, N310=3, N311=2. Timer T310 is stopped and reset when N311 consecutive In-Sync notifications have been forwarded. When timer T310 expires, a radio link failure is detected.

[0094] If a radio link failure is detected in the primary serving cell and a security mode procedure and a data radio bearer are set up, the UE initiates an RRC connection re-establishment procedure to restore the connection. This procedure includes initiating a random access procedure and sending a re-establishment request (RRCConnectionReestablishmentRequest or RRCReestablishmentRequest). If a radio link failure is detected in the primary serving cell and a security mode procedure or at least one data radio bearer is set up, the UE releases the connection itself and transitions to the RRC Idle state. For further details on radio link failure, see 3GPP TS 23.100, Section 13.9.2.

[0095] Similar to the link failure detection in the UE described above, link failure detection is also performed in the NCR device, for example, for links including the control link. Link failure detection can be performed by the NCR, for example, by counting instances of out-of-sync notification, instances of link failure, or, in beamforming operation, instances of beam failure, and comparing the counter with a configured threshold, such as beamFailureInstanceMaxCount.

[0096] In the event of a link failure, the NCR may need to be de-configured. "De-configuration" may include stopping relaying and notifying the serving gNB that the configuration has been de-configured. Once de-configured, the NCR will no longer relay. The gNB must re-configure the NCR. The NCR may be configured semi-statically by RRC signaling.

[0097] <Further improvements> As mentioned above, the gNB can configure the NCR via a control link in a periodic, semi-static, or dynamic manner. For example, a periodic configuration can be applied to a particular beam pattern (or can be appropriate for SSB transmission of CSI-RS transmission), and a dynamic configuration can be configured for UE scheduling.

[0098] However, the inventors have recognized that a failure may occur in the control link between the NCR and the gNB, which triggers a link recovery procedure in the NCR similar to the link recovery procedure described above for the UE. The parameters that trigger the link recovery procedure may be configured by the RRC and may be, for example, a beam failure instance (BFI), a radio link failure instance, and / or the number of out-of-sync measurements. These parameters, and possibly the ability of the NCR-MT to identify a new working beam, may determine the delay incurred to restore the control link after a failure occurs.

[0099] A control link failure may lead to the NCR releasing the (relay) transmission configuration, e.g., beam configuration. The NCR then needs to be reconfigured, resulting in increased signaling overhead. However, as the inventors point out, after the control link is restored by a link failure recovery mechanism, the NCR is likely to be configured with a portion of its previous configuration, e.g., a periodic beam pattern.

[0100] An example is shown in Figures 7A and 7B, where the NCR is initially served by a gNB on beam #i, as shown in Figure 7A. After the link recovery procedure, the NCR is served by the same gNB on beam #i+1, as shown in Figure 7B. The same periodic beam pattern is used for the NCR to serve the UE both before and after radio link recovery. The periodic time pattern is shown at the bottom of the figure, where the beams are provided, for example, within one or more symbols of a slot. Here, the NCR serves the UE on beams j-2 to j+2, while simultaneously being served by the gNB on beam i before recovery and beam i+1 after recovery.

[0101] <Embodiment> The present inventors have identified the possibility of obtaining a reconfiguration of an NCR device from an existing transmission configuration in the event of a control link failure between the NCR and a gNB, e.g., a control link failure due to a radio link failure. The present disclosure relates to various solutions and variations to such a procedure. Thus, the present disclosure provides techniques for improving the efficiency of a communication system comprising a relay node, e.g., by reducing signaling overhead associated with the reconfiguration.

[0102] The present disclosure provides, inter alia, a scheduling apparatus, a corresponding method of the scheduling apparatus, a communication apparatus (e.g., a communication apparatus adapted / configured to perform the functions of a relay node in a communication system), a corresponding method and (computer) program (e.g., a program stored in a memory) of the communication apparatus, a communication system comprising such a scheduling apparatus and communication apparatus, and an integrated circuit which, in operation, controls the processes of the scheduling apparatus / communication apparatus to perform the respective methods.

[0103] An example of such a communication system is shown in Figure 8. The communication system 800 may be a wireless communication system conforming to 5G technical specifications, particularly an NR communication system, although the present disclosure is not limited to a 3GPP NR terrestrial network (TN) and may also be applied to NTN, other wireless systems, or cellular systems.

[0104] FIG. 8 illustrates a general and simplified exemplary block diagram of a communication device 810 (exemplary here as a relay node) and a scheduling device 860 or scheduling node (exemplary here as assumed to be located in a base station, e.g., an eNB (also referred to as ng-eNB) in LTE or a gNB in ​​5G NR). Generally, however, the scheduling device may be a terminal in the case of a sidelink connection between two terminals. Furthermore, particularly with regard to URLLC, eMBB, and mMTC use cases, the communication device 810 may be a sensor device, a wearable device, or a controller for a connected vehicle or an automated machine in an industrial factory. The communication device 810 may function as a relay between a base station and other communication devices.

[0105] As shown in Figure 8, a communication device 810 and a scheduling device 860 (eNB / gNB) may communicate with each other over a (wireless) physical channel 850 using their respective transceivers 820 (relay node side) and 870 (base station side). The scheduling device 860 and the relay node 810 together constitute a communication system 800. The communication system 800 may further include other entities as shown in Figure 1, in particular other communication devices to which the relay node relays signals from the base station and / or other communication devices to which the relay node receives signals that the relay node relays to the base station.

[0106] <Transmitter / receiver and circuit> As shown in FIG. 8 (left side), the communication device may comprise a transceiver and a circuit (or processing circuit), and the scheduling device may comprise a transceiver and a (processing) circuit.

[0107] Note that the term "transceiver" refers to a front-end including one or more antennas (or multiple antennas if beamforming is used). The transceiver here may include an amplifier, several modulators for modulating baseband signals onto a system carrier, a possible digital-to-analog converter, and possible further signal-improvement circuitry. Generally, a transceiver may comprise and / or function as a receiver and / or a transmitter. In other words, in this disclosure, "transceiver" refers to hardware and software components that enable a communication device to transmit and / or receive wireless signals over a wireless channel. Thus, a transceiver corresponds to a receiver, a transmitter, or a combination of a receiver and a transmitter. Typically, base stations and communication devices are assumed to be capable of both transmitting and receiving wireless signals. However, for some applications, particularly eMBB, mMTC, and URLLC (e.g., smart home, smart city, industrial automation), devices such as sensors may only receive signals. The transmitter may be responsible for processing transmissions and other related processing. The receiver may be responsible for processing receptions and other related processing, such as channel monitoring. Generally, a transceiver may be controlled by a circuit to perform transmission and / or reception.

[0108] As used herein, the term "circuitry" refers to any hardware and / or software, including, for example, one or more processors (or processing units or any LSI), microcontrollers, programmable hardware such as FPGAs (field programmable gate arrays), and / or dedicated hardware such as ASICs (application-specific integrated circuits), and may further include digital or analog circuits.

[0109] Between the transceiver and the processing circuitry, there may be input / output points (or nodes) at which the processing circuitry, in operation, can control the transceiver, i.e., control the receiver and / or transmitter, and exchange receive and transmit data. The processing circuitry may perform control tasks such as transmitting user data and control data provided by the processing circuitry and / or controlling the transceiver to receive user data and control data that is further processed by the processing circuitry. The processing circuitry may also be responsible for performing other processes, such as judging, determining, calculating, measuring, etc.

[0110] According to one exemplary embodiment, a communications device 810 is provided as illustrated in FIG. 8 (left side). The communications device 810 includes a transceiver 820 and a circuit 830. The transceiver 820, in operation, receives control signaling indicating a relay transmission configuration. The circuit 830, in operation, determines whether a wireless link is operational. If the circuit 830 determines that the wireless link is operational, the communications device 810 relays a signal, and the transceiver 820, in operation, receives the relayed signal using the relay transmission configuration and transmits the received relayed signal. If the circuit 830 determines that a wireless link failure has occurred in determining whether the wireless link is operational, the circuit 830, in operation, performs wireless link recovery. After wireless link recovery is successfully completed, the transceiver 820, in operation, receives the relayed signal using the relay transmission configuration and transmits the received signal.

[0111] Circuitry 830 is illustratively thought of as including link status and configuration determination circuitry 835, which determines whether the wireless link is operational or whether a wireless link failure has occurred. Note, however, that circuitry 830 may implement more functionality than the relay transmission configuration determination and wireless link mobility determination discussed above, and may, for example, further control transceiver 820. In particular, circuitry 830 may control transceiver 820 to relay signals and to transmit and receive control signaling.

[0112] 9 illustrates an exemplary structure of the link state and configuration determination circuit 835. As shown, the exemplary link state and configuration determination circuit includes a relay configuration determination circuit 910, a link state determination circuit 920, and a link recovery circuit 930. The relay configuration determination circuit 910 may be responsible for determining a relay transmission configuration, for example, based on received control signaling. The link state determination circuit 920 may be responsible for determining whether a wireless link is operational, for example, a wireless link failure. The link recovery circuit 930 may be responsible for performing wireless link recovery when a wireless link failure is detected.

[0113] However, the circuits 830, 835, 910, 920, 930 may implement more functions than the above-described relay transmission configuration determination and radio link mobility determination, e.g., may further control the transceiver 820. In particular, the circuit 830 may control the transceiver 820 to perform relay transmission of signals and to perform transmission and reception of control signaling. For example, the circuit may be configured to determine resources for transmitting and receiving data, particularly resources for relay transmission and transmission of control signaling. In particular, the time (e.g., start, end, and / or length) of a transmission may be determined by the circuit. For example, the transceiver 820 may receive signaling including an indication indicating resources for transmission (e.g., of a scheduling DCI), the circuit may obtain the indication from the signaling, and the relay may determine resources based on the obtained indication.

[0114] Corresponding to the above-described communication device, a communication method executed by the communication device is provided. As shown in FIG. 10 , the method includes a step S1010 of receiving a transmission configuration. The method further includes a step S1020 of determining whether the wireless link is operational or whether a wireless link failure has occurred. If it is determined in step S1020 that the wireless link is operational, a relaying step S1030 is executed. Step S1030 includes receiving a signal to be relayed and transmitting the received signal using the relay transmission configuration. It should be noted that the step S1010 of checking the wireless link and the relaying step S1030 are repeatedly and continuously executed unless a wireless link failure occurs. Furthermore, the order is not limited to the order described above. If it is determined in step S1020 that a wireless link failure has occurred, the method proceeds to a step S1040 of performing wireless link recovery. After the wireless link recovery is successfully completed, the method proceeds to a relaying step S1030 of receiving a signal to be relayed and transmitting the relayed signal.

[0115] Also provided is a scheduling node 860 or scheduling device, e.g., a base station, as illustrated in Fig. 8 (right side). The scheduling node 860 comprises a transceiver 870 and a circuit 880. The transceiver 870, in operation, generates a relay transmission configuration. The transceiver 870, in operation, transmits control signaling including the relay transmission configuration.

[0116] The transceiver may transmit signals to be relayed and / or receive relayed signals according to the relay transmission configuration.

[0117] The scheduling node circuitry 880 is illustratively considered to include relay setup circuitry 885 as shown in FIG.

[0118] Corresponding to the scheduling node 860, a communication method performed by the scheduling node is provided. As shown in Figure 11, the method includes a step S1110 of generating a relay transmission configuration and a step S1120 of transmitting control signaling including the relay transmission configuration.

[0119] The communication method of the scheduling node may further include a step S1130 of transmitting a signal to be relayed and / or receiving a relayed signal according to the relay transmission configuration.

[0120] Hereinafter, to easily distinguish between the components of the communication device 810 and the scheduling node 850, or the above-described methods thereof, the terms "NCR" and "gNB" are used, for example, as "NCR transceiver unit 820," "gNB circuitry 880," or "NCR method." However, these terms and names are exemplary and do not limit the present disclosure to any standard or technology.

[0121] Furthermore, in this disclosure, details, embodiments, and examples, such as those described below, apply equally to both the communications device 810 and the scheduling node 860, as well as the apparatus and methods described above.

[0122] Thus, in step S1020, it is determined whether a radio link is operational, for example, by the NCR circuitry 830. Such a radio link may correspond to a link between the scheduling node 860 and the communication device 810 and may include a serving beam through which the communication device 810 is served by the scheduling node 860. For example, the radio link may include the control link shown in FIG.

[0123] Furthermore, determining whether a radio link is operational may be similar to the beam failure or radio link failure determination and detection described above, e.g., Beam Failure Detection (BFD) and Radio Link Monitoring (RLM). In particular, link failure may be detected if the number of link failures, beam failures, or out-of-sync measurements exceeds a threshold. Link recovery may also be performed similar to the link recovery and beam recovery mechanisms described above. In multi-beam operation, link recovery may include identifying a new communication beam or serving beam.

[0124] In addition, the reception and transmission of relayed signals corresponds to the relay function performed by a relay communication device such as an NCR, and includes, for example, receiving and amplifying signals between the gNB and the UE using, for example, an RU unit 660 (NCR-Fwd), as shown in Figure 6.

[0125] In this disclosure, "using a relay transmission setting" or "transmitting or receiving a signal according to a relay transmission setting" refers to applying at least one setting or parameter from the relay transmission setting when transmitting or receiving a relay signal or a signal to be relayed.

[0126] A "relayed signal" may include multiple signals transmitted and / or received at different time instances, for example, before and after radio link restoration, and may carry the same or different data.

[0127] The relayed signals may include one or both of uplink and downlink signals, and may also include sidelink signals. Furthermore, the relayed signals may carry control data and / or user data or payload data. In this disclosure, the term "relayed signals" is intended to include any data. The relay communication device 810 functions as a relay node for signals between, for example, the scheduling node and the UE, and therefore does not need to retrieve and process data from the signals it relays.

[0128] The relay transmission configuration may include or indicate one or more of the following settings:

[0129] -Beamforming settings - Configuring Time Division Duplex (TDD) operation in the uplink and downlink - On / off information indicating whether to turn on or off the relay transmission operation of the communication device -Power control information The beamforming information may indicate a time pattern that defines which beam is served at which time instance, such as a slot or symbol. For example, the beam pattern may be a periodic beam pattern. A beam or radio beam is a direction used in directional transmission in which transmit power is concentrated. For example, in 5G NR, different beams may be represented by a Transmission Configuration Indicator (TCI) state in control signaling.

[0130] The relay transmission configuration may be configured by the RRC. For example, the NCR may be configured with a semi-static configuration (e.g., semi-persistent scheduling (SPS) or configured grant (CG) transmission) for transmissions to and from the UE.

[0131] Configuration for TDD operation may include a slot configuration that associates symbols within a slot with the following symbol types: uplink symbols, downlink symbols, flexible symbols, and (in applicable communication systems) sidelink symbols.

[0132] As mentioned above, the ON-OFF information may be used for efficient interference management and improved energy efficiency, and the power control information may be used for interference management.

[0133] By using or reusing a relay transmission configuration after a radio link recovery has successfully completed, the present disclosure facilitates reducing signaling overhead in signaling new transmission configurations or parameters for new transmission configurations.

[0134] <settings defined for a set of cells> As described above, after the relay communication device 810 such as an NCR has successfully completed wireless link recovery, it relays signals using the same relay transmission settings as before the wireless link failure.

[0135] In some embodiments, a relay transmission configuration is defined for multiple scheduling nodes, e.g., base stations, gNBs, cells, or Transmission and Reception Points (TRPs), e.g., including settings for the parameters mentioned above, i.e., beamforming configuration, TDD, ON-OFF information, power, etc. After (successful completion of) the radio link recovery procedure, the existing (e.g., already in use before the radio link failure) relay transmission configuration is applied to the defined set of scheduling nodes, cells, etc.

[0136] After the radio link recovery is successfully completed, the relay communication device 810 may be connected to the same scheduling node as before the radio link failure, or may be connected to another scheduling node from the defined set.

[0137] For example, the set for which the configuration is defined may be a plurality of scheduling nodes, including a first scheduling node to which the communication device 810 was connected before the radio link failure and a second scheduling node to which the communication device connects during a radio link recovery procedure. When the communication device 810 connects to the second scheduling node during radio link recovery, the NCR transceiver 820, in operation, receives signals to be relayed and transmits the received signals using the relay transmission configuration after the radio link recovery is successfully completed. Correspondingly, in step S1030 of the NCR method, after connecting to the second scheduling node during radio link recovery, relaying is performed using the (existing) relay transmission configuration.

[0138] For example, transmission configurations for the NCR 810 (e.g., including beam ON-OFF information, power, and / or UL-DL TDD configurations) are defined for a set of serving gNBs, cells, and TRPs. When a radio link failure occurs, the NCR stops amplifying the signal and initiates a link recovery procedure. When the link is restored for the set of gNBs / cells, the NCR applies the existing defined transmission configurations.

[0139] In the case of multi-TRP communication, the relay communication device 810 may apply defined transmission configurations to the first plurality of TRPs and to the second plurality of TRPs before and after radio link recovery.

[0140] Returning to the example shown in Figures 7A and 7B, the NCR is configured with, for example, periodic beam settings or periodic beam patterns for SSB and / or RS transmissions that are periodically performed in time. A set of gNBs including the current serving gNB (the "first" scheduling node) is defined. If the current serving gNB fails, the NCR performs a link recovery procedure. If the recovered link is with one of the gNBs in the defined set (e.g., again with the first scheduling node or another "second" scheduling node), the beam settings configured similar to the beam settings before recovery are reapplied rather than reconfigured.

[0141] <offset> In connection with the above embodiments, an example has been described in which the same periodic beam pattern is applied without change before and after radio link recovery. According to some embodiments, an offset value is defined for each gNB, cell, or TRP. When the NCR connects to a new gNB, cell, or TRP, the offset value associated with it is applied to the transmission configuration.

[0142] For example, an NCR may be configured or defined with offset (e.g., resource offset for time, frequency, etc.) values ​​for each of multiple scheduling nodes (e.g., gNBs), cells, or TRPs. If a radio link failure occurs for the NCR, the NCR may initiate a link recovery procedure and connect to another gNB, cell, or TRP. In such a case, the offset value associated with the other, newly connected scheduling node is applied to the existing transmission configuration.

[0143] In some embodiments, the relay transmission configuration defined for the set or plurality of communication nodes includes a respective resource offset for each of the plurality of scheduling nodes. In performing radio link recovery, when the communication device 810 connects to a second scheduling node, the NCR transceiver 820, in operation, applies the resource offset for the second scheduling node to the beamforming configuration when transmitting signals received after the radio link recovery has been successfully completed.

[0144] Correspondingly, in step S1120 of the gNB method, a relay configuration may be generated including a resource offset for each of the multiple scheduling nodes.

[0145] In a corresponding communication method, the resource offset is applied in a relaying step S1030 after connecting to the second scheduling node upon successful recovery of the radio link.

[0146] An offset or resource offset may be defined for one or more portions or parameters of a configuration, such as a beam pattern configuration, a TDD configuration, etc. For example, in the example of beam pattern or TDD information, a time offset, e.g., in slots and / or symbols, may be applied to the time pattern. Other examples of offsets include frequency offsets, spatial / directional offsets (e.g., beams), etc., or transmit / receive power offsets, etc. Furthermore, for example, if an offset is defined for a beam configuration, other portions of the relay configuration, e.g., ON-OFF information or power information, may not be affected by the offset.

[0147] In the example shown in Figures 12A and 12B, before the radio link recovery procedure, NCR is served by scheduling node gNB1. NCR is configured with a periodic beam pattern, e.g., for SSB / RS transmission. An offset value for gNB2 is defined. When a link failure occurs at NCR, NCR performs a link recovery procedure and connects to gNB2. NCR applies the offset value of gNB2 to its beam pattern configuration.

[0148] As shown in Figures 12A and 12B, a UE may be served by gNB1 on beam #i before radio link recovery and then on beam #k after radio link recovery. In either case, NCR serves the UE on the configured beam patterns, beams j-2 to j+2. However, when served by gNB2 on beam #k, NCR applies a symbol offset (or other time offset) to the beam patterns of beams j-2 to j+2.

[0149] The offset configuration may facilitate seamless relaying upon radio link failure when relay nodes transparent to the UE are used. For example, a time offset may compensate for different locations of the gNB or TRP or their distance to the NCR, and a frequency offset may compensate for different channel conditions (e.g., when considering simultaneous transmission and reception by the NCR).

[0150] <Radio link recovery time threshold> In some embodiments, which may be combined with the above examples and embodiments, the relay transmission configuration is configured with a time threshold, and if the duration of the link failure is less than the time threshold or counter, the relay transmission configuration remains in effect for the NCR.

[0151] For example, the NCR may be configured to trigger link recovery procedures earlier than the UEs served by the NCR to avoid large-scale link failures by the UEs served by the NCR. For such earlier triggering, a parameter or count threshold used for link failure detection or beam failure detection, e.g., beamFailureInstanceMaxCount, may be configured for the NCR that is smaller than the value for the served UEs, as described below. If the link recovery procedure for the NCR is performed and the NCR recovers in a sufficiently short time instance, the transmission configuration and relay transmission configuration for the UE may still be used because the served UEs did not initiate the link recovery procedure.

[0152] To this end, a relay transmission configuration (e.g., associated with a UE served by an NCR) can be assigned a time threshold, and if the NCR identifies a link failure and successfully performs and completes a link recovery procedure within the time threshold, the transmission configuration remains valid after recovery.

[0153] Based on the above, in some embodiments, the NCR transceiver 820, in operation, performs relaying (e.g., receiving and transmitting relayed signals) using the (existing) relay transmission configuration if the circuit achieves radio link recovery within a time period equal to or less than the radio link recovery time threshold, and the NCR circuit 830, in operation, releases the relay transmission configuration if the circuit exceeds the radio link recovery time threshold when performing radio link recovery.

[0154] Correspondingly, as shown in FIG. 13, the NCR method may include step S1350, during radio link recovery, determining whether a time threshold for radio link recovery has been exceeded. For example, the NCR may maintain a timer that is started upon detection of the radio link failure and compared to the time threshold for radio link recovery. If radio link recovery is completed within the time threshold, the relay setting configured according to step S1030 is used to receive and transmit relayed signals, as before the radio link failure. If the time threshold has been exceeded, the NCR method proceeds to step S1360, where the relay transmission setting is released.

[0155] For example, the control signaling received by the relay communication device 810 from the scheduling node may include a configured time threshold, which may be included in or associated with the relay transmission configuration, and the NCR circuitry 830, in operation, may determine a time threshold for radio link recovery that is equal to or less than the configured time threshold.

[0156] For example, the set time threshold may be less than or equal to the UE's time threshold used in beam failure detection so that the NCR completes radio link recovery before the UE detects the link failure.

[0157] Furthermore, to initiate link recovery well before the UE detects the link failure, the count threshold for link failure instances used by the relay communication device 810 ("relay count threshold", e.g., count threshold for a maximum number of out-of-sync, link, or beam failures) may be assigned a value lower than the UE ("terminal count threshold") for the NCR. The NCR (e.g., NCR circuitry 830) may maintain a counter that counts instances of link failure and compare the number of instances of link failure that occur within a given time period to the count threshold.

[0158] In some embodiments, the control signaling received from the scheduling node 860 includes a relay count threshold for the number of radio link failure instances at which radio link recovery is triggered by the communications device, and the NCR circuitry 830, in operation, triggers radio link recovery when a counter value indicating the number of radio link failure instances reaches (or exceeds) the relay count threshold. For example, the determination of whether the counter value has reached or exceeded the relay count threshold may be made in step S1020 of the NCR method. For example, the relay count threshold may be set by the parameter beamFailureInstanceMaxCount described above.

[0159] When the NCR circuit 830 releases the relay transmission setting, the NCR transceiver 820 may transmit a signal indicating that the relay transmission setting has been released. For example, the signal may be transmitted to notify the gNB of the release. The gNB may then determine a new relay transmission setting for the NCR.

[0160] An example of the application of time thresholds to NCR radio link recovery is shown in Figure 14. NCR is configured with semi-static beam configuration for the UE's SPS or CG traffic. The beam configuration is associated with a time threshold and counter corresponding to the time period and counter for the UE's beam failure detection. For example, the time threshold corresponds to the UE's beam failure detection (BFD) threshold. NCR performs a link recovery procedure for the control link. Since NCR recovers the link within the configured threshold, the NCR beam configuration for the SPS / CG traffic remains valid after the NCR link recovery procedure.

[0161] By enabling radio links to be restored within a time threshold, this embodiment may, for example, facilitate reducing signaling overhead associated with reconfiguration and may reduce the likelihood of experiencing large scale UE link failures.

[0162] <Relay Setup Release in UE's BFD / RLF> In this embodiment, as in the previous section of this disclosure, a transmission setup is set together with a time threshold. When the duration of the interruption of the control link (e.g., interruption due to radio link failure (RLF) or beam failure recovery (BFR)) is longer than the time threshold, the transmission setup is released by the NCR. Optionally, the NCR notifies the gNB that the transmission setup has been released.

[0163] However, in this embodiment, the beam failure recovery or link recovery procedure of the control link may be triggered by the NCR_MT at a time later than the time when the recovery procedure is triggered by the served UE. For example, the UE has URLLC traffic, and the link recovery procedure of the UE may be set to be triggered quickly. In such a case, the served UE may start the link recovery procedure before the NCR detects the link failure. The UE may, for example, release the semi-static settings related to SPS / CG transmission. And even if the NCR does not start the link recovery procedure, it is desirable that the NCR can release the relevant (relay) transmission setup.

[0164] For this purpose, a time threshold and a timer or counter can be assigned to the transmission setup. If the NCR cannot recover the beam and / or link of the control link within the set time threshold, the relevant settings may be released. Optionally, the NCR may also notify the gNB that the transmission setup has been released.

[0165] In some embodiments, the control signaling indicates a terminal count threshold for the number of instances of radio link failure where the radio link recovery is triggered by the terminal communication device. The NCR circuit 830, during operation, releases the relay transmission setup when the counter value indicating the number of instances of radio link failure reaches or exceeds the terminal count threshold.

[0166] For example, the NCR circuit 830 may cancel the relay transmission setting when the counter value indicating the number of instances of radio link failure reaches or exceeds the terminal count threshold within the timer threshold of the terminal for determining radio link failure or beam failure.

[0167] Similar to the previous section, when the NCR circuit 830 cancels the relay transmission setting, the transceiver may transmit a signal indicating that the relay transmission setting has been cancelled to the scheduling node 860 during operation.

[0168] FIG. 15 is a diagram showing an example in which NCR is set with a semi-static beam setting and serves UE SPS / CG traffic. The beam setting is associated with a time threshold or a count threshold equal to the UE's time threshold and / or count threshold for BFD. However, the count threshold of NCR for triggering radio link recovery may be larger than the UE's count threshold. Therefore, NCR may detect beam failure instances over a period longer than the UE's time threshold, and may detect radio link or beam failure only after the UE has detected beam failure or radio link failure. NCR does not initiate the link recovery procedure but cancels the associated semi-static beam setting. For example, as shown in FIG. 15, NCR cancels the beam setting when the UE starts link recovery.

[0169] According to this embodiment, when NCR cancels the radio link setting in response to the trigger of radio link or beam recovery of the UE, NCR does not amplify the UE's signal when the UE is in the link recovery procedure. Thereby, interference in the communication system can be reduced.

[0170] <Threshold Signaling by gNB> In some embodiments, on the side of the scheduling node 860, in addition to generating the relay transmission setting, the gNB circuit 880 determines a plurality of count thresholds for the number of instances of radio link failure. The plurality of count thresholds include the following.

[0171] A relay count threshold applied by the relay communication device at which radio link recovery is triggered or relay transmission is de-configured. At least one terminal count threshold applied by the terminal communication device, at which radio link recovery is triggered In operation, the gNB transceiver 870 transmits a relay transmission configuration and multiple count thresholds, and transmits a signal to be relayed or receives a relayed signal according to the relay transmission configuration.

[0172] 16 shows an example structure of the scheduling node's relay configuration circuit 885. The example relay configuration circuit includes a relay configuration generation circuit 1510 responsible for generating relay transmission configurations, and a threshold determination circuit 1520 responsible for determining the time thresholds and the above-mentioned multiple count thresholds referred to in this disclosure.

[0173] Correspondingly, as shown in Figure 17, in addition to the steps described with reference to Figure 11, the method of the gNB may include a threshold determination step S1615 for determining a threshold comprising a plurality of count thresholds for the number of instances of radio link failure. The plurality of count thresholds include:

[0174] A relay count threshold applied by the relay communication device at which radio link recovery is triggered or relay transmission is de-configured. At least one terminal count threshold applied by the terminal communication device, at which radio link recovery is triggered Then, the method includes a step S1625 of transmitting the determined threshold value.

[0175] For example, a relay count threshold may be transmitted to the relay communication device 810 and a terminal count threshold may be transmitted to one or more UEs that transmit or receive signals relayed through the communication device 810 .

[0176] In some embodiments, the at least one terminal count threshold includes a first terminal count threshold that is greater than the relay count threshold, e.g., corresponding to the embodiment described above in the "Time Threshold for Radio Link Recovery" section with reference to FIG.

[0177] In addition to the multiple count thresholds, the above-mentioned time threshold for radio link recovery may be generated (e.g., by the gNB circuitry 870), transmitted (e.g., by the gNB transceiver unit 870), and used in combination with the relay count threshold by the relay communication device 810 (e.g., NCR) to enable rapid radio link recovery and reuse of existing relay transmission settings if radio link recovery is completed within the time threshold.

[0178] In some embodiments, the at least one terminal count threshold includes a second terminal count threshold that is equal to the relay count threshold for deactivating the transmission configuration, e.g., corresponding to the embodiment described above in the section "Deactivating Relay Configuration in UE BFD / RLF" with respect to Figure 15, in which the NCR deactivates the relay transmission configuration upon the UE detecting a beam or radio link failure.

[0179] The first and second terminal count thresholds may be provided to a first UE or multiple UEs and a second UE or multiple UEs, respectively, in combination with, for example, a single cell or a set of neighboring cells having a common relay configuration as described above. For example, the second UE or multiple UEs may include a URLLC device. Thus, the communication system can balance avoiding large-scale link failures with reducing interference.

[0180] Hardware and Software Implementations of the Disclosure The present disclosure can be implemented by software, hardware, or software operating in conjunction with hardware. Each functional block used in the above-described embodiments can be implemented, in whole or in part, by an LSI such as an integrated circuit. Each process described in each embodiment can be controlled, in whole or in part, by the same LSI or a combination of LSIs. The LSI can be formed as an individual chip, or a single chip can be formed to include some or all of the functional blocks. The LSI can include a data input / output unit coupled to it. Depending on the level of integration, the LSI can also be referred to as an IC (integrated circuit), system LSI, super LSI, or ultra LSI. However, the technology for implementing an integrated circuit is not limited to LSI, and can be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, FPGAs (field programmable gate arrays), which can be programmed after LSI fabrication, and reconfigurable processors, which can reconfigure the connections and settings of circuit cells arranged within the LSI, can also be used. The present disclosure can be implemented using digital or analog processing. If, as a result of advances in semiconductor technology or other derivative technologies, LSI is replaced by future integrated circuit technologies, these future integrated circuit technologies can be used to integrate functional blocks. Biotechnology can also be applied.

[0181] The present disclosure can be implemented by any type of apparatus, device, or system having a communication function, referred to as a communication apparatus. For example, relay nodes, network nodes, and scheduling apparatuses are considered as communication apparatuses.

[0182] The communication device may include a transceiver and a processing / control circuit. The transceiver may include a receiver and a transmitter and / or function as both a receiver and a transmitter. The transceiver as a transmitter and a receiver may include an RF (radio frequency) module including an amplifier, an RF modulator / demodulator, etc., and one or more antennas.

[0183] Some non-limiting examples of such communication devices include telephones (e.g., mobile phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices), game consoles, e-readers, telehealth / telemedicine devices, vehicles (e.g., cars, airplanes, ships) that provide communication capabilities, and various combinations thereof.

[0184] Communication devices are not limited to portable or mobile devices, but can also include any type of equipment, device, or system that is non-portable or fixed, such as smart home devices (e.g., appliances, lights, smart meters, control panels), vending machines, and any other "thing" in an "Internet of Things" (IoT) network.

[0185] Communication can include, for example, exchanging data through cellular systems, wireless LAN systems, satellite systems, etc., and various combinations thereof.

[0186] A communications device may include devices such as a controller or a sensor coupled to the communications device to perform the communications functions described in this disclosure. For example, a communications device may include a controller or a sensor that generates control or data signals used by the communications device to perform the communications functions of the communications device.

[0187] The communications apparatus may further include infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicate with or control apparatuses such as the apparatuses in the non-limiting examples above.

[0188] Furthermore, various embodiments may be implemented by software modules, which are executed by a processor or directly in hardware. A combination of software modules and hardware implementation is also possible. The software modules may be stored on any type of computer-readable storage medium. In particular, according to another implementation, a non-transitory computer-readable storage medium is provided. The storage medium stores a program that, when executed by one or more processors, causes the one or more processors to perform the steps of a method according to the present disclosure.

[0189] By way of non-limiting example, such computer-readable storage media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is referred to as a computer-readable medium, as appropriate. For example, if instructions are transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of medium. However, it should be understood that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transitory media, but instead cover non-transitory tangible storage media. As used herein, a disc includes a compact disc (CD), a laser disc, an optical disc, a digital versatile disc (DVD), a floppy disk, and a Blu-ray disc, where a "disk" typically reproduces data magnetically, while a "disc" reproduces data optically with a laser. Combinations of the above should also be included within the scope of computer-readable media.

[0190] Furthermore, it should be noted that individual features of different embodiments may be the subject of other embodiments, individually or in any combination. Those skilled in the art will appreciate that the present disclosure, as set forth in the specific embodiments, may be subject to various changes and / or modifications without departing from the concept or scope of the invention as broadly described. The embodiments described herein are therefore to be considered in all respects as illustrative and not restrictive.

[0191] <Aspect> According to a first aspect, there is provided a communications device comprising: a transceiver unit that, in operation, receives control signaling indicating a relay transmission configuration; and circuitry that, in operation, determines whether a wireless link is operational, wherein if the circuitry determines that the wireless link is operational, the transceiver unit, in operation, receives a signal to be relayed using the relay transmission configuration and transmits the received signal; if the circuitry determines that a wireless link failure has occurred, the circuitry, in operation, performs wireless link recovery, and after the wireless link recovery is successfully completed, the transceiver unit, in operation, receives the signal to be relayed using the relay transmission configuration and transmits the received signal.

[0192] A second aspect may be provided in conjunction with the first aspect, wherein the relay transmission configuration is defined for a plurality of scheduling nodes including a first scheduling node and a second scheduling node, the radio link is a first radio link between the communication device and the first scheduling node, and when the communication device connects to the second scheduling node when performing the radio link recovery, the transceiver unit, in operation, receives the signal to be relayed and transmits the received signal using the relay transmission configuration after the radio link recovery is successfully completed.

[0193] A third aspect may be provided in conjunction with the second aspect, wherein the relay transmission configuration includes: -Beamforming settings, -configuring time division duplex operation in uplink and downlink; - On / off information indicating the timing to turn on and off the relay transmission operation of the communication device, or - power control information, Contains one or more of the following:

[0194] A fourth aspect may be provided in conjunction with the third aspect, wherein the relay transmission configuration includes a resource offset for each of the plurality of scheduling nodes, and when the communication device connects to the second scheduling node when performing the radio link recovery, the transceiver unit, in operation, applies the resource offset for the second scheduling node to the beamforming configuration when transmitting the signal received after the radio link recovery has been successfully completed.

[0195] A fifth aspect may be provided in combination with any one of the first to fourth aspects, wherein the transceiver unit, in operation, receives the signal to be relayed using the relay transmission setting if the circuitry performs the radio link recovery within a time period equal to or less than a time threshold for the radio link recovery, and transmits the received signal, and the circuitry, in operation, releases the relay transmission setting if the circuitry exceeds the time threshold for the radio link recovery when performing the radio link recovery.

[0196] A sixth aspect may be provided in conjunction with the fifth aspect, wherein the control signaling includes a set time threshold, and wherein the circuit, in operation, determines the time threshold for the radio link recovery to be less than or equal to the set time threshold.

[0197] A seventh aspect may be provided in conjunction with the fifth or sixth aspect, wherein the control signaling includes a relay count threshold for the number of instances of radio link failure at which the radio link recovery is triggered by the communication device, and wherein, in operation, the circuit triggers the radio link recovery when a counter value indicating the number of instances of radio link failure reaches the relay count threshold.

[0198] An eighth aspect may be provided in combination with any one of the first to fifth aspects, wherein the control signaling indicates a terminal count threshold for the number of instances of radio link failure at which radio link recovery is triggered by the terminal communication device, and wherein the circuit, in operation, releases the relay transmission configuration when a counter value indicating the number of instances of radio link failure reaches the terminal count threshold.

[0199] A ninth aspect may be provided in combination with any one of the fifth to eighth aspects, wherein when the circuit cancels the relay transmission setting, the transceiver unit, when operating, transmits a signal indicating that the relay transmission setting has been canceled.

[0200] According to a tenth aspect, there is provided a scheduling node comprising: circuitry that, in operation, generates a relay transmission configuration and determines a plurality of count thresholds for a number of instances of radio link failure, the plurality of count thresholds including relay count thresholds applied by a relay communication device to trigger radio link recovery or release the relay transmission configuration, and at least one terminal count threshold applied by a terminal communication device to trigger radio link recovery, and a transceiver unit that, in operation, transmits control signaling including the relay transmission configuration and the plurality of count thresholds.

[0201] An eleventh aspect may be provided in conjunction with the tenth aspect, wherein the transceiver unit, when operating, transmits a signal to be relayed or receives a relayed signal in accordance with the relay transmission setting.

[0202] A twelfth aspect may be provided in conjunction with the tenth or eleventh aspects, wherein the at least one terminal count threshold comprises a first terminal count threshold that is greater than the relay count threshold.

[0203] A thirteenth aspect may be provided in conjunction with the twelfth aspect, wherein the circuit, in operation, determines a time threshold for the radio link recovery to be applied by the relay communication device, and the control signaling includes the time threshold for the radio link recovery.

[0204] A fourteenth aspect may be provided in combination with any one of the tenth to thirteenth aspects, wherein the at least one terminal count threshold includes a second terminal count threshold equal to the relay count threshold that releases the transmission setting.

[0205] A fifteenth aspect may be provided in conjunction with any one of the tenth to fourteenth aspects, wherein the relay transmission configuration is defined for a plurality of scheduling nodes including the scheduling node.

[0206] A sixteenth aspect may be provided in combination with any one of the tenth to fifteenth aspects, wherein the relay transmission setting is -Beamforming settings, -configuring time division duplex operation in uplink and downlink; - On / off information indicating the timing to turn on and off the relay transmission operation of the communication device, or - power control information, Contains one or more of the following:

[0207] A seventeenth aspect may be provided in conjunction with the sixteenth aspect, wherein the relay transmission configuration includes a resource offset for each of the plurality of scheduling nodes.

[0208] An 18th aspect may be provided in combination with any one of the 10th to 17th aspects, wherein when the transceiver unit receives a signal indicating that the transmission setting has been released, the circuit, in operation, generates a reset relay transmission setting, and the transceiver unit, in operation, transmits control signaling to reconfigure the relay setting device in accordance with the reset relay transmission setting, and transmits the signal to be relayed or receives the relayed signal in accordance with the relay transmission setting.

[0209] According to a nineteenth aspect, there is provided a communication method, the communication method comprising: receiving, performed by a communication device, control signaling indicating a relay transmission configuration and determining whether a radio link is operational, wherein if it is determined that the radio link is operational, the method comprises receiving a signal to be relayed using the relay transmission configuration and transmitting the received signal, and if it is determined that a radio link failure has occurred, the method comprises performing radio link recovery, and after the radio link recovery is successfully completed, receiving the signal to be relayed using the relay transmission configuration and transmitting the received signal.

[0210] A twentieth aspect may be provided in conjunction with the nineteenth aspect, wherein the relay transmission configuration is defined for a plurality of scheduling nodes including a first scheduling node and a second scheduling node, the radio link is a first radio link between the communication device and the first scheduling node, and when the communication device connects to the second scheduling node in the step of performing the radio link recovery, the method includes a step of receiving the signal to be relayed using the relay transmission configuration and transmitting the received signal after the radio link recovery is successfully completed.

[0211] A twenty-first aspect may be provided in combination with the twentieth aspect, wherein the relay transmission setting includes: -Beamforming settings, -configuring time division duplex operation in uplink and downlink; - On / off information indicating the timing to turn on and off the relay transmission operation of the communication device, or - power control information, Contains one or more of the following:

[0212] A 22nd aspect may be provided in conjunction with the 21st aspect, wherein the relay transmission configuration includes a resource offset for each of the plurality of scheduling nodes, and in the step of performing the radio link recovery, if the communication device connects to the second scheduling node, the method includes a step of applying the resource offset for the second scheduling node to the beamforming configuration when transmitting the signal received after the radio link recovery has been successfully completed.

[0213] A 23rd aspect may be provided in combination with any one of the 19th to 22nd aspects, wherein the steps of receiving the signal to be relayed using a relay transmission setting and transmitting the received signal are performed if the radio link recovery is performed within a time period equal to or less than a time threshold for the radio link recovery, and the method includes a step of releasing the relay transmission setting if the time threshold for the radio link recovery is exceeded in performing the radio link recovery.

[0214] A 24th aspect may be provided in conjunction with the 23rd aspect, wherein the control signaling includes a set time threshold, and the method includes determining the time threshold for the radio link recovery to be less than or equal to the set time threshold.

[0215] A 25th aspect may be provided in conjunction with the 23rd or 24th aspects, wherein the control signaling includes a relay count threshold for the number of instances of radio link failure at which the radio link recovery is triggered by the communication device, and the method includes a step of triggering the radio link recovery when a counter value indicating the number of instances of radio link failure reaches the relay count threshold.

[0216] A 26th aspect may be provided in conjunction with any one of the 19th to 23rd aspects, wherein the control signaling indicates a terminal count threshold for the number of instances of radio link failure at which radio link recovery is triggered by the terminal communication device, and the method includes a step of releasing the relay transmission configuration when a counter value indicating the number of instances of radio link failure reaches the terminal count threshold.

[0217] A 27th aspect may be provided in combination with any one of the 23rd to 26th aspects, wherein the method includes, when the relay transmission setting is canceled, transmitting a signal indicating that the relay transmission setting has been canceled.

[0218] According to a 28th aspect, there is provided a communication method, the communication method comprising: steps, executed by a scheduling node, of generating a relay transmission configuration, determining a plurality of count thresholds for a number of instances of radio link failure, the plurality of count thresholds including a relay count threshold, applied by a relay communication device, that triggers radio link recovery or releases the relay transmission configuration, and at least one terminal count threshold, applied by a terminal communication device, that triggers radio link recovery, and transmitting control signaling including the relay transmission configuration and the plurality of count thresholds.

[0219] A 29th aspect may be provided in conjunction with the 28th aspect, wherein the method includes a step of transmitting a signal to be relayed or receiving a relayed signal according to the relay transmission setting.

[0220] A thirtieth aspect may be provided in conjunction with the twenty-eighth or twenty-ninth aspects, wherein the at least one terminal count threshold includes a first terminal count threshold that is greater than the relay count threshold.

[0221] A 31st aspect may be provided in conjunction with the 30th aspect, wherein the method includes a step of determining a time threshold for the radio link recovery to be applied by the relay communication device, and in a step of transmitting control signaling, the control signaling includes the time threshold for the radio link recovery.

[0222] A 32nd aspect may be provided in conjunction with any one of the 28th to 31st aspects, wherein the at least one terminal count threshold includes a second terminal count threshold equal to the relay count threshold that releases the transmission setting.

[0223] A thirty-third aspect may be provided in conjunction with any one of the twenty-eighth to thirty-second aspects, wherein the relay transmission configuration is defined for a plurality of scheduling nodes including the scheduling node.

[0224] A 34th aspect may be provided in combination with any one of the 28th to 33rd aspects, and the relay transmission setting may include: -Beamforming settings, -configuring time division duplex operation in uplink and downlink; - On / off information indicating the timing to turn on and off the relay transmission operation of the communication device, or - power control information, Contains one or more of the following:

[0225] A thirty-fifth aspect may be provided in conjunction with the thirty-fourth aspect, wherein the relay transmission configuration includes a resource offset for each of the plurality of scheduling nodes.

[0226] A 36th aspect may be provided in combination with any one of the 28th to 35th aspects, wherein the method includes the steps of: when receiving a signal indicating that the transmission setting has been released, generating a reset relay transmission setting and transmitting control signaling to reconfigure the relay setting device in accordance with the reset relay transmission setting; and transmitting the signal to be relayed or receiving the relayed signal in accordance with the relay transmission setting.

[0227] According to a thirty-seventh aspect, there is provided an integrated circuit which, in operation, causes a communications device to perform the steps of the communications method according to any one of the nineteenth to twenty-seventh aspects.

[0228] According to a thirty-eighth aspect, there is provided an integrated circuit that, in operation, causes a scheduling node to perform the steps of the communication method according to any one of the twenty-eighth to thirty-sixth aspects.

[0229] According to a 39th aspect, there is provided a program recorded on a (non-transitory) recording medium and comprising code instructions which, when executed on one or more processors of a communication device, cause the one or more processors to perform the steps of any one of the 19th to 27th aspects.

[0230] According to a 40th aspect, there is provided a program recorded on a (non-transitory) recording medium and comprising code instructions which, when executed on one or more processors of a scheduling node, cause the one or more processors to perform the steps of the 28th to 36th aspects.

Claims

1. A communication device, a transceiver unit configured to receive control signaling indicative of a relay transmission configuration during operation; circuitry that, in operation, determines whether the wireless link is operational; If the circuit determines that the wireless link is operational, The transceiver unit, during operation, receives a signal to be relayed using the relay transmission setting and transmits the received signal; If the circuit determines that a radio link failure has occurred, The circuitry, in operation, performs wireless link recovery; In operation, after the radio link recovery is successfully completed, the transceiver receives the signal to be relayed using the relay transmission setting and transmits the received signal. Communication equipment.

2. the relay transmission configuration is defined for a plurality of scheduling nodes including a first scheduling node and a second scheduling node, and the wireless link is a first wireless link between the communication device and the first scheduling node; and if the communication device connects to the second scheduling node when performing the radio link recovery, the transceiver unit, in operation, receives the signal to be relayed using the relay transmission configuration and transmits the received signal after the radio link recovery is successfully completed. The communication device according to claim 1 .

3. The relay transmission setting is Beamforming settings, Configuring time division duplex operation in the uplink and downlink; On / off information indicating the timing to turn on and off the relay transmission operation of the communication device; or power control information, including one or more of: The communication device according to claim 2 .

4. the relay transmission configuration includes, for each of the plurality of scheduling nodes, a resource offset; and if the communication device connects to the second scheduling node when performing the radio link recovery, the transceiver unit, in operation, applies the resource offset for the second scheduling node to the beamforming configuration when transmitting the signal received after the radio link recovery is successfully completed. The communication device according to claim 3 .

5. the transceiver unit, in operation, receives the signal to be relayed and transmits the received signal using the relay transmission configuration if the circuitry recovers the radio link within a time period equal to or less than a time threshold for the radio link recovery; and wherein the circuit, in operation, when performing the radio link recovery, releases the relay transmission setting if the circuit exceeds the time threshold for the radio link recovery. A communication device according to any one of claims 1 to 4.

6. the control signaling includes a configured time threshold; the circuit, in operation, determines the time threshold for the radio link recovery to be less than or equal to the set time threshold. The communication device according to claim 5 .

7. the control signaling includes a relay count threshold for the number of instances of radio link failure at which the radio link restoration is triggered by the communication device; In operation, the circuitry triggers the radio link recovery when a counter value indicating the number of instances of the radio link failure reaches the relay count threshold. The communication device according to claim 1 .

8. the control signaling indicates a terminal count threshold for the number of instances of radio link failure at which radio link recovery is triggered by the terminal communication device; In operation, the circuitry cancels the relay transmission configuration when a counter value indicating the number of instances of the radio link failure reaches the terminal count threshold. The communication device according to claim 1 .

9. When the circuit cancels the relay transmission setting, the transceiver unit, during operation, transmits a signal indicating that the relay transmission setting has been canceled. The communication device according to claim 5 .

10. a scheduling node, A circuit that, in operation, generates a relay transmission configuration and determines a number of count thresholds for a number of instances of radio link failure, the number of count thresholds comprising: a relay count threshold applied by the relay communication device to trigger radio link recovery or to release the relay transmission setting; a circuit including at least one terminal count threshold applied by the terminal communication device to trigger radio link recovery; a transceiver unit that, in operation, transmits control signaling including the relay transmission configuration and the plurality of count thresholds; A scheduling node comprising:

11. the at least one terminal count threshold includes a first terminal count threshold greater than the relay count threshold; The scheduling node of claim 10.

12. The circuitry, in operation, determines a time threshold for the radio link recovery to be applied by the relay communication device; the control signaling includes the time threshold for the radio link recovery. The scheduling node of claim 11.

13. the at least one terminal count threshold includes a second terminal count threshold equal to the relay count threshold that cancels the transmission setting; A scheduling node according to any one of claims 10 to 12.

14. 1. A communication method comprising the steps of: receiving control signaling indicating a relay transmission configuration; determining whether the wireless link is operational; If the wireless link is determined to be operational, the method receiving a signal to be relayed using the relay transmission configuration and transmitting the received signal; If it is determined that a radio link failure has occurred, the method further comprises: performing radio link recovery; receiving the signal to be relayed and transmitting the received signal using the relay transmission configuration after the radio link recovery is successfully completed; A communication method, including:

15. A communication method comprising the steps executed by a scheduling node: generating a relay transmission configuration; determining a plurality of count thresholds for a number of instances of radio link failure, the plurality of count thresholds comprising: a relay count threshold applied by the relay communication device to trigger radio link recovery or to release the relay transmission setting; at least one terminal count threshold applied by the terminal communication device to trigger radio link recovery; transmitting control signaling including the relay transmission configuration and the plurality of count thresholds; A communication method, including:

16. In operation, the communication device: receiving control signaling indicating a relay transmission configuration; determining whether the wireless link is operational, If the wireless link is determined to be operational, the circuitry receiving a signal to be relayed using the relay transmission configuration and transmitting the received signal; If it is determined that a radio link failure has occurred, the circuitry performing radio link recovery; receiving the signal to be relayed and transmitting the received signal using the relay transmission configuration after the radio link recovery is successfully completed; An integrated circuit that performs the

17. During operation, the scheduling node: generating a relay transmission configuration; determining a plurality of count thresholds for a number of instances of radio link failure, the plurality of count thresholds comprising: a relay count threshold applied by the relay communication device to trigger radio link recovery or to release the relay transmission setting; at least one terminal count threshold applied by the terminal communication device to trigger radio link recovery; transmitting control signaling including the relay transmission configuration and the plurality of count thresholds; An integrated circuit that performs the

Images