Beam Obstruction Recovery for M-TRP URLLC Transmission Based on One DCI

Abstract

The present invention provides multiple mechanisms for enabling flexibility in M-TRP URLLC operation and reducing measurement effort and power consumption of a transceiver device, such as a UE. The transceiver unit, in operation, receives signals on at least a PDSCH from multiple transmission / reception points (M-TRPs) in a network. The circuit, in operation, performs beam failure recovery (BFR) by performing beam failure detection (BFD) and new beam candidate detection (CBD) evaluations on the signals from a first TRP among the M-TRPs. The signals from the first TRP among the M-TRPs include signals received on a PDCCH, and the circuit determines, in response to one or more conditions, to skip evaluation of one or both of the BFD and the CBD for one or more additional TRPs among the M-TRPs.

Description

Technical Field

[0001] The present invention relates to a communication device, and more particularly, to a mechanism for beam outage recovery for such a communication device.

Background Art

[0002] In modern society, communication devices are widespread in various forms. Examples include telephones, tablets, computers, cameras, digital audio / video players, wearable devices, game consoles, telehealth / telemedicine devices, vehicles with communication functions, and combinations of the above various devices. Communication includes data communication by cellular systems, wireless LAN (local area network) systems, communication satellite systems, etc., as well as data communication by combinations thereof.

[0003] As communication generations progress (e.g., 5G NR: 5G new Radio), ultra-reliable and low-latency communications (URLLC) are required for many applications (e.g., Augmented Reality / Virtual Reality (AR / VR), e-health, e-safety, mission-critical applications). URLLC has strict requirements for performance such as throughput, latency, and availability, and is envisioned as one of the enablers for future vertical applications such as wireless control of industrial production and manufacturing processes, remote medical surgery, power distribution automation in smart grids, and traffic safety. Also, 5G NR is equipped with multiple transmission and reception points (M-TRP) to improve reliability, coverage, and capacity performance through flexible deployment scenarios. For example, a user equipment (UE) (i.e., a communication device) is expected to access a network consisting of M-TRP (e.g., macrocell, small cell, picocell, femtocell, remote radio head, relay node) to cope with the rapid increase in mobile data traffic in 5G and expand coverage.

Summary of the Invention

Problems to be Solved by the Invention

[0004] During operation, the UE can access signals from the M-TRP. The UE determines that the signal from one of the M-TRPs has been lost by means of a beam failure detection (BFD) procedure. Then the UE attempts to restore communication through a process that includes new beam identification (NBI), also known as candidate new beam detection (CBD). Both BFD and CBD are essential UE processes for maintaining ultra-high reliability and low latency in URLLC communication. On the other hand, measurement effort and power consumption are essential for recovery from beam failure, including the BFD and CBD processes.

[0005] Therefore, there is a need for a communication device and system that can save power without losing the reliability of URLLC communication during recovery from a beam failure state. Further, other desirable features and characteristics will become apparent from the following detailed description and the appended claims in conjunction with the accompanying drawings and their background.

Means for Solving the Problem

[0006] Non-limiting and exemplary embodiments of the present disclosure contribute to providing multiple mechanisms that achieve flexibility in the operation of M-TRP URLLC (multiple transmission and reception point ultra-reliable low-latency communication) and reduce measurement effort and power consumption in a transceiver device such as a UE.

[0007] In one embodiment, the technology disclosed herein features a transceiver device having a transceiver unit and a circuit. The transceiver unit, during operation, receives signals at least via a physical downlink shared channel (PDSCH) from a plurality of transmission and reception points (M-TRP: multiple transmission and reception points) within a network. The circuit, during operation, performs beam failure recovery by evaluating beam failure detection (BFD) and candidate new beam detection (CBD) on the signals from a first TRP among the M-TRP. The signal from the first TRP among the M-TRP includes a signal received via a physical downlink control channel (PDCCH), and the circuit determines to skip the evaluation of one or both of the BFD and the CBD for one or more additional TRPs among the M-TRP according to one or more conditions.

[0008] Note that these general or specific aspects may be implemented in a system, method, integrated circuit, computer program, or recording medium, or may be implemented in any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium.

[0009] Further advantages and effects in an embodiment of the present disclosure will be clarified from the specification and the drawings. Such advantages and / or effects are respectively provided by some embodiments and the features described in the specification and the drawings, but not necessarily all are provided to obtain one or more identical features.

Brief Description of the Drawings

[0010] In the following, exemplary embodiments will be described in more detail with reference to the accompanying drawings.

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[0011] A person skilled in the art can understand that the elements in the figures are shown simply and clearly and are not necessarily drawn to a certain scale.

Embodiments for Carrying Out the Invention

[0012] The following detailed description is essentially merely exemplary and is not intended to limit the application and use of exemplary embodiments or exemplary embodiments. Furthermore, there is no intention to be bound by any theory presented in the foregoing background or the following detailed description. The present disclosure is intended to present exemplary embodiments of a communication device and a communication system that save power without losing the reliability of URLLC (ultra-reliable and low-latency communications) communication during recovery from a beam failure state, thereby reducing the measurement effort and power consumption during BFR while maintaining ultra-reliable and low-latency communication.

[0013] <5G NR System Architecture and Protocol Stack> The 3GPP (3rd Generation Partnership Project) is working on the next release of the 5th generation cellular technology (simply referred to as 5G), including the development of new radio access technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, enabling the trial and commercial deployment of smartphones compliant with the 5G NR standard.

[0014] Referring to FIG. 1, in particular, the overall system architecture assumes an NG-RAN (Next Generation-Radio Access Network) 102 with a gNB (gNodeB) 104. The gNB provides the UE-side termination of the user plane (SDAP / PDCP / RLC / MAC / PHY) and radio resource control (RRC: Radio Resource Control) protocol for NG radio access. The gNBs 104 are interconnected by an Xn interface 106. Also, the gNB is connected to a next-generation core (NGC: Next Generation Core) 112 via a next-generation (NG: Next Generation) interface, more specifically, to an access and mobility management function (AMF: Access and Mobility Management Function) 108 (e.g., a specific core entity that executes the AMF) via an NG-C interface 112a, and to a user plane function (UPF: User Plane Function) 110 (e.g., a specific core entity that executes the UPF) via an NG-U interface 112b. The NG-RAN architecture 100 is shown in FIG. 1 (see, for example, section 4 of 3GPP TS 38.300 v15.6.0).

[0015] The user plane protocol stack of NR (see, for example, section 4.4.1 of 3GPP TS 38.300) includes the PDCP (Packet Data Convergence Protocol; see section 6.4 of TS 38.300), RLC (Radio Link Control; see section 6.3 of TS 38.300), and MAC (Medium Access Control; see section 6.2 of TS 38.300) sublayers that are terminated on the network side at the gNB. Further, a new access stratum (AS) sublayer (SDAP: Service Data Adaptation Protocol) is introduced above PDCP (see, for example, sub-clause 6.5 of 3GPP TS 38.300). Also, the control plane protocol stack is defined in NR (see, for example, section 4.4.2 of TS 38.300). An overview of the layer 2 functions is described in sub-clause 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are described in sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are enumerated in sub-clause 7 of TS 38.300.

[0016] For example, the MAC layer is responsible for scheduling and scheduling-related functions, including multiplexing of logical channels and processing of various numerologies.

[0017] The physical layer (PHY) is responsible for, for example, encoding, PHY HARQ processing, modulation, multi-antenna processing, and the allocation of signals to appropriate physical time-frequency resources. It also performs the allocation 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 allocated to a corresponding physical channel. For example, the physical channels are PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel) in the uplink, and PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel) in the downlink.

[0018] The use cases / deployment scenarios of NR include eMBB (enhanced Mobile Broadband), URLLC (Ultra-Reliable Low-Latency Communications), mMTC (massive Machine Type Communication), etc., which have diverse requirements regarding data rate, latency, and coverage. For example, in eMBB, peak data rates (20 Gbps downlink, 10 Gbps uplink) and effective (user-experienced) data rates approximately three times those provided by IMT-Advanced are required. On the other hand, in URLLC, more stringent requirements are for ultra-low latency (user plane latency is 0.5 ms for both UL and DL) and high reliability (1 - 10 within 1 ms) -5) is imposed. Finally, mMTC preferably requires a high connection density (1 million devices per square kilometer in an urban environment), wide coverage in harsh environments, and an ultra-long-life battery (15 years) for low-cost devices.

[0019] 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 be effective for other use cases. For example, low-latency services may preferably require a shorter symbol length (and thus a larger subcarrier spacing) and / or fewer symbols per scheduling interval (in other words, TTI) than mMTC services. Furthermore, in a deployment scenario with a large channel delay spread, a longer CP length may preferably be required than in a scenario with a short delay spread. In order to maintain a similar CP overhead, the subcarrier spacing needs to be optimized as appropriate. In NR, multiple values of subcarrier spacing may be supported. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz,... are currently being considered. The symbol length T u and the subcarrier spacing Δf are directly related by the formula Δf = 1 / T u Similar to the LTE system, the term "resource element" can be used to indicate the smallest resource unit composed of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0020] In the new radio system 5G-NR, for each numerology and carrier, a resource grid of subcarriers and OFDM symbols is defined for each of the uplink and downlink. Each element in the resource grid is called a resource element and is identified based on the frequency index in the frequency domain and the symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0021] <Functional Split between NG-RAN and 5GC> (Control signal) In the present disclosure, the downlink control signal (information) related to the present disclosure may be a signal (information) transmitted on the physical layer PDCCH, or may be a signal (information) transmitted by the upper layer MAC CE (Control Element) or RRC. It may also be a signal (information) defined in advance.

[0022] The uplink control signal (information) related to the present disclosure may be a signal (information) transmitted on the physical layer PUCCH, or may be a signal (information) transmitted by the upper layer MAC CE or RRC. It may also be a signal (information) defined in advance. It may also be replaced with UCI (uplink control information), 1st stage SCI (sidelink control information), or 2nd stage SCI.

[0023] (Base station) In the present disclosure, the base station may be a TRP (Transmission Reception Point), cluster head, access point, RRH (Remote Radio Head), eNodeB (eNB), gNodeB (gNB), BS (Base Station), BTS (Base Transceiver Station), master unit, gateway, etc. In sidelink communication, it may also be a terminal instead of the base station. It may also be a relay device that relays communication between the upper node and the terminal. It may also be a roadside unit.

[0024] (Uplink / Downlink / Sidelink) The present disclosure may be applied to any of uplink, downlink, and sidelink.

[0025] For example, the present disclosure may be applied to PUSCH, PUCCH, PRACH in the uplink, PDSCH, PDCCH, PBCH in the downlink, and PSSCH (Physical Sidelink Shared Channel), PSCCH (Physical Sidelink Control Channel), PSBCH (Physical Sidelink Broadcast Channel) in the sidelink.

[0026] Note that 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. PSCCH and PSSCH are examples of a sidelink control channel and a sidelink data channel, respectively. PBCH and PSBCH are notification (broadcast) channels, and PRACH is an example of a random access channel.

[0027] (Data Channel / Control Channel) The present disclosure may be applied to either a data channel or a control channel. For example, the channels of the present disclosure may be replaced with PDSCH, PUSCH, PSSCH of the data channel and PDCCH, PUCCH, PBCH, PSCCH, PSBCH of the control channel.

[0028] (Reference Signal) In the present disclosure, the reference signal is a signal known to both the base station and the mobile station, and may also be called an RS (Reference Signal) or a pilot signal. The reference signal may be any one of DMRS, CSI-RS (Channel State Information-Reference Signal), TRS (Tracking Reference Signal), PTRS (Phase Tracking Reference Signal), CRS (Cell-specific Reference Signal), and SRS (Sounding Reference Signal).

[0029] (Time Interval) In the present disclosure, the unit of time resource is not limited to one or a combination of a slot and a symbol. For example, it may be a time resource unit such as a frame, a superframe, a subframe, a slot, a time slot sub-slot, a mini-slot, or a symbol, an OFDM (Orthogonal Frequency Division Multiplexing) symbol, an SC-FDMA (Single Carrier-Frequency Division Multiplexing) symbol, or other time resource units. Also, the number of symbols included in one slot is not limited to the number of symbols exemplified in the above-described embodiments, and other numbers of symbols may be used.

[0030] (Frequency band) The present disclosure may be applied to either a licensed band or an unlicensed band.

[0031] (Communication) The present disclosure may be applied to any of communication between a base station and a terminal (Uu link communication), communication between terminals (sidelink communication), and V2X (Vehicle to Everything) communication. For example, the channels of the present disclosure may be replaced with PSCCH, PSSCH, PSFCH (Physical Sidelink Feedback Channel), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, PBCH.

[0032] Further, the present disclosure may be applied to either a terrestrial network or a non-terrestrial network (NTN: Non-Terrestrial Network) using satellites or high-altitude pseudo satellites (HAPS: High Altitude Pseudo Satellite). Also, it may be applied to a terrestrial network with a large cell size or a very wideband transmission network where the transmission delay is large compared to the symbol length and slot length.

[0033] (Antenna port) An antenna port refers to a logical antenna (antenna group) composed of one or more physical antennas. That is, an antenna port does not necessarily refer to a single physical antenna, and may refer to an array antenna composed of multiple antennas. For example, it is not specified how many physical antennas an antenna port is composed of, and it is defined as the minimum unit by which a terminal can transmit a reference signal. Also, an antenna port may be defined as the minimum unit for multiplying the weights of a precoding vector.

[0034] Figure 2 shows the functional split between the NG-RAN 200 and the 5GC 250. The NG-RAN logical node is the gNB or ng-eNB 210. The 5GC 250 includes the logical nodes of the AMF 260, UPF 270, and SMF 280.

[0035] The gNB and ng-eNB 210 specifically provide the following main functions. · Radio resource management functions 212 such as radio bearer control 214, radio admission control 218, connection mobility control 216, and dynamic resource allocation (scheduling) 222 to the UE in both the uplink and downlink · IP header compression, encryption, and integrity protection of data · AMF selection at UE attachment when the routing to the AMF cannot be determined from the information provided by the UE · Routing of user plane data towards the UPF · Routing of control plane information towards the AMF · Establishment and release of connections · Scheduling and transmission of paging messages · Scheduling and transmission of system information messages (sent from the AMF or OAM) · Measurement and measurement report configuration 220 for mobility and scheduling · Transport level packet marking in the uplink · Session management · Support for network slicing · QoS flow management and mapping to data radio bearers · Support for UE in RRC_INACTIVE state · NAS message delivery function · Radio access network sharing · Dual connectivity · Tight cooperation between NR and E-UTRA

[0036] The Access and Mobility Management Function (AMF) 260 provides the following main functions. · Termination of non-access stratum (NAS) signaling · NAS signaling security 262 · Access stratum (AS) security control · Core network (CN) node - to - node signaling for mobility between 3GPP access networks · Reachability of idle mode UEs (including control and execution of paging retransmission) 264 · Registration area management · Support for in - system and inter - system mobility · Access authentication · Access authorization including roaming rights check · Mobility management control (subscription and policy) · Support for network slicing · Selection of Session Management Function (SMF)

[0037] Furthermore, the User Plane Function (UPF) provides the following main functions. · Anchor point for RAT - in / RAT - out mobility (when applicable) 272 · External PDU session point for interconnection with data networks 274 · Packet routing and forwarding · Packet inspection and enforcement of policy rules in the user plane part (Policy rule enforcement) · Reporting of traffic usage · Uplink classifier that supports routing of traffic flows to the data network · Branch point that supports multi-homed PDU sessions · QoS processing for the user plane such as packet filtering, gating, UL / DL (uplink / downlink) rate enhancement · Uplink traffic verification (placement for QoS flows of SDFs) · Downlink packet buffering and downlink data notification trigger

[0038] Finally, the Session Management Function (SMF) 280 provides the following main functions. · Session management 284 · Assignment and management of IP addresses for the UE 282 · Selection and control of the UPF · Configuration of traffic steering in the User Plane Function (UPF) for routing traffic to the appropriate destination · Enforcement of control part policies and QoS · Notification of downlink data

[0039] <RRC connection setup and reconfiguration procedures> Figure 3 shows a part of the interaction between the UE 310, the gNB 320, and the AMF 330 (5GC entity) when the UE moves from RRC_IDLE to RRC_CONNECTED in the NAS part (see TS 38.300 v15.6.0).

[0040] RRC is the upper layer signaling (protocol) used for the configuration of the UE and gNB. This transition specifically involves the AMF330 preparing UE context data (including, for example, PDU session context, security keys, UE Radio Capability, UE Security Capabilities, etc.) and sending it to the gNB320 together with an INITIAL CONTEXT SETUP REQUEST 340. Then, the gNB320 activates AS security with the UE310. This operation is carried out by the gNB sending a SecurityModeCommand message 342 to the UE and the UE310 responding to the gNB320 with a SecurityModeComplete message 344. After that, the gNB320 sends an RRCReconfiguration message 346 to the UE310, and upon receiving the RRCReconfigurationComplete 348 from the UE310 in response, it performs a reconfiguration to set up the Signaling Radio Bearer 2 (SRB2) and the Data Radio Bearer (DRB). In the case of a signaling-only connection, since the SRB2 and DRB are not set up, the steps related to RRC reconfiguration are omitted. Finally, the gNB320 notifies the AMF330 in an INITIAL CONTEXT SETUP RESPONSE 350 that the configuration procedure is complete.

[0041] Therefore, in the present disclosure, an entity (e.g., AMF, SMF, etc.) of a fifth-generation core (5GC) is provided, which includes a control circuit that establishes a next-generation (NG) connection with a gNodeB during operation, and a transmission unit that transmits an initial context setup message to the gNodeB via the NG connection during operation so that a signaling radio bearer between the gNodeB and a terminal (UE) is set. Specifically, the gNodeB transmits radio resource control (RRC) signaling including a resource allocation setting information element to the UE via the signaling radio bearer. Then, the UE performs uplink transmission or downlink reception based on the resource allocation setting.

[0042] <IMT Usage Scenarios After 2020> Figure 4 shows a part of the use cases of 5G NR. In the 3rd Generation Partnership Project NR (3GPP NR), three use cases that are expected to support a variety of services and applications by IMT-2020 are being considered. The formulation of the first-phase specifications for enhanced mobile broadband (eMBB) 410 has been completed. In addition to further expanding the support for eMBB 410, currently and in the future, research on the standardization of ultra-reliable low-latency (URLLC) 430 and massive machine-type communications (mMTC) 450 is also underway. Figure 4 shows an example of the usage scenarios assumed for IMT after 2020 (see, for example, Figure 2 of ITU-R M.2083).

[0043] The use case 430 of URLLC has strict requirements for performance such as throughput, latency, and availability, and is envisioned as one of the enablers for future vertical applications such as wireless control of industrial production and manufacturing processes, remote medical surgery, power distribution automation in smart grids, and traffic safety. The ultra-high reliability of URLLC 430 is supported by identifying technologies that meet the requirements set by TR 38.913. For NR URLLC in Release 15, the main requirement is to target a user plane latency of 0.5 ms for UL (uplink) and 0.5 ms for DL (downlink). The general requirement for URLLC 430 for a single packet transmission is that when the user plane latency is 1 ms, the block error rate (BLER) is 1E-5 for a packet size of 32 bytes.

[0044] From a physical layer perspective, there are various ways to improve reliability. Currently, to improve reliability, it is conceivable to define an independent CQI table for URLLC 430, a more compact DCI (downlink control information) format, repetition of PDCCH, etc. However, as NR becomes more stable and evolved (with respect to the main requirements of NR URLC), the range of methods considered for achieving ultra-high reliability can expand. The use cases specific to NR URLLC in Release 15 include extended reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0045] In addition, the technical enhancements targeted by NR URLLC 430 are delay improvement and reliability improvement. Technical enhancements for delay improvement include configurable numerology, non-slot-based scheduling by flexible mapping, grant-free uplink (of a configured grant), slot-level repetition of the data channel, and downlink pre-emption. Pre-emption means stopping a transmission for which resources have already been allocated and using the said resources that have already been allocated for another transmission that is requested later and requires less delay or higher priority. Therefore, a transmission that has already been permitted is replaced by a later transmission. Pre-emption can be applied regardless of the specific service type. For example, a transmission of service type A (URLLC) may be pre-empted by a transmission of service type B (e.g., eMBB). Technical enhancements for reliability improvement include a dedicated CQI / MCS table for a target BLER of 1E-5.

[0046] The characteristics of the use cases of mMTC (massive machine type communication) 450 are typically that there are an extremely large number of connected devices that transmit a relatively small amount of data and are not easily affected by delay. The devices are required to be low-cost and have a very long battery life. From the perspective of NR, using a very narrow bandwidth part is one measure that enables power saving for the UE and a long battery life.

[0047] As described above, the scope of reliability improvement in NR is expected to be broader. One of the important requirements common to all cases, especially those necessary for URLLC430 and mMTC450, is high reliability or ultra-high reliability. To improve reliability, several mechanisms can be considered from the wireless and network perspectives. Generally, there are several important areas that contribute to reliability improvement. These areas include compact control channel information, repetition of data / control channels, diversity in the frequency domain, time domain, and spatial domain. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0048] Regarding NR URLLC430, additional use cases with more stringent requirements have been identified, such as factory automation, the transportation industry, and power distribution. The more stringent requirements are high reliability (up to 10 -6 levels), high availability, a packet size of up to 256 bytes, time synchronization up to about a few microseconds (μs) (which can be 1 μs or several μs depending on the frequency range and a short delay of about 0.5 to 1 millisecond (ms), e.g., a 0.5 ms delay in the target user plane).

[0049] Furthermore, in NR URLLC430, several technical enhancements have been identified from the perspective of the physical layer. These include enhancements to the Physical Downlink Control Channel (PDCCH) related to compact DCI, repetition of the PDCCH, and increased monitoring of the PDCCH. Also, the enhancement of uplink control information (UCI) is related to the enhancement of extended Hybrid Automatic Repeat Request (HARQ) and CSI feedback. Enhancements to the Physical Uplink Shared Channel (PUSCH) related to mini-slot level hopping and retransmission / repetition have also been confirmed. A "mini-slot" represents a transmission time interval (TTI) that contains fewer symbols than a slot (a slot composed of 14 symbols).

[0050] <QoS Control> The 5G QoS (Quality of Service) model is based on QoS flows and caters to 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, a QoS flow is the finest-grained QoS classification in a PDU session. A QoS flow is identified within a PDU session by a QoS flow ID (QFI) that is carried in the encapsulation header via the NG-U interface.

[0051] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one data radio bearer (DRB) according to the PDU session, and additional DRBs for the QoS flows of that PDU session can be configured later (when to configure depends on the NG-RAN), for example, as described above with reference to Figure 3. The NG-RAN arranges packets belonging to different PDU sessions in different DRBs. NAS-level packet filters in the UE and the 5GC associate UL packets and DL packets with QoS flows, while AS-level mapping rules in the UE and the NG-RAN associate UL QoS flows and DL QoS flows with DRBs.

[0052] Figure 5 shows the non-roaming reference architecture of 5G NR (see TS 23.501 v16.1.0, Section 4.23). Application functions (AF) 500, such as external application servers that host 5G services, as illustrated in Figure 4, interact with the 3GPP core network to provide services. For example, accessing the Network Exposure Function (NEF) 505 to support applications that affect traffic routing, and interacting with the policy framework for policy control such as QoS control (see Policy Control Function (PCF)). Based on operator deployment, application functions 500 considered trusted by the operator can interact directly with the relevant network functions. Application functions 500 not permitted by the operator to directly access network functions use the external exposure framework via the NEF 505 to interact with the relevant network functions.

[0053] Figure 5 shows further functional units of the 5G architecture, namely, the Network Slice Selection Function (NSSF) 510, the Network Repository Function (NRF) 515, the Unified Data Management (UDM) 520, the Authentication Server Function (AUSF) 525, the Access and Mobility Management Function (AMF) 530, the Session Management Function (SMF) 535, and the Data Network (DN) 540 (operator services, Internet access, third-party services, etc.). All or some of the core network functions and application services may be deployed and operate on a cloud computing environment.

[0054] Therefore, in the present disclosure, in order to establish a PDU session including a radio bearer between a gNodeB and a UE according to QoS requirements, during operation, a request including QoS requirements for at least one of URLLC, eMBB, and mMTC services is transmitted to at least one of the functions of the 5GC (for example, NEF505, AMF530, SMF535, PCF545, UPF550, etc.), and during operation, a control circuit that executes a service using the established PDU session is provided. An application server (for example, AF500 of the 5G architecture) is provided.

[0055] FIG. 6 shows an example of a multi-transmission and reception point (M-TRP) ultra-reliable and low-latency (URLLC) network 600 based on one downlink control information (DCI). M-TRP transmission is used to overcome interference effects and improve the performance of the UE 602 at the edge of the cell. In M-TRP URLLC transmission based on one DCI, the network 600 schedules PDSCH transmissions 610, 612 from a plurality of TRPs (that is, TRP1 620 and TRP2 622), and the PDSCHs 610, 612 from different TRPs 620, 622 are transmitted on different layers (that is, layer 1 630 and layer 2 632).

[0056] To facilitate further downselection of one or more schemes in RAN1#96bis, the schemes for multi-TRP-based URLLC scheduled by at least one DCI are defined by the following schemes 2, 2a, and 2b for frequency division multiplexing (FDM) and schemes 3 and 4 for time division multiplexing (TDM).

[0057] Scheme 2 (FDM): In a single slot with non-overlapping frequency resource allocation, n (n ≦ N) f(number of) TCI states. Each non-overlapping frequency resource allocation is associated with one TCI state, and the same single / multiple DMRS ports are associated with all non-overlapping frequency resource allocations.

[0058] Scheme 2a (FDM): One codeword of one RV is used across all resource allocations. From the perspective of the UE, a common RB mapping (codeword for layer mapping such as Rel-15) is applied across the entire resource allocation.

[0059] Scheme 2b (FDM): One codeword of one RV is used for each non-overlapping frequency resource allocation. The RVs corresponding to each non-overlapping frequency resource allocation may be the same or different. It can be considered to apply different MCS / modulation orders for different non-overlapping frequency resource allocations.

[0060] Details of the FDM2a / 2b frequency resource allocation mechanism regarding the allocation granularity and time domain allocation can also be considered.

[0061] Scheme 3 (TDM): n (n ≦ Nt1) TCI states in a single slot with non-overlapping time resource allocations. Each transmission opportunity of the TB has one TCI and one RV at the time granularity of the mini-slot. Across all transmission opportunities in the slot, a common MCS including the same single or multiple DMRS ports is used. The RV / TCI states may be the same or different across transmission opportunities. Channel estimation interpolation (detailed consideration) is performed across mini-slots with the same TCI index.

[0062] Scheme 4 (TDM): n (n ≦ Nt2) TCI states in K (n ≦ K) different slots. Each transmission opportunity of the TB has one TCI and one RV. Across all transmission opportunities over the K slots, a common MCS including the same, single or multiple DMRS ports is used. The RV / TCI states may be the same or different between transmission opportunities. And channel estimation interpolation (detailed study) is performed across slots with the same TCI index.

[0063] Note that the M-TRP / panel-based URLLC schemes should be compared in terms of reliability improvement, efficiency, and impact on the specifications, and the support for the number of layers per TRP may be considered.

[0064] In the case of FDM, in Schemes 2a and 2b, according to Scheme 2a, the number of transmission configuration indication (TCI) states is set to 2, supporting a maximum of two transmission layers. Also in Schemes 3 and 4 in the case of TDM, the number of TCI states is set to 2. Resource allocation in the time domain supports the same number of consecutive symbols scheduled for each transmission opportunity. In the case of Scheme 3, with the network (NW) implementation, all transmission opportunities exist in one slot without being dropped, and the details of the downlink / uplink (DL / UL) switching within the slot are considered.

[0065] The UE can be configured to receive PDSCH from a maximum of two TRPs, depending on the number of configured TCI states. Figure 7 shows a general beam failure recovery procedure 700 that includes four main steps. The first step is beam failure detection (BFD) 702. The UE is provided with a list of reference signals (RS) for detecting beam failure by failureDetectionResources. Alternatively, if the RS is not provided by failureDetectionResources, the UE performs BFD 702 based on the TCI state for PDCCH / PDSCH reception (see Section 6 of TS 38.213 and Section 8.5 of TS 38.133).

[0066] The next step is new beam identification (NBI), also known as candidate new beam detection (CBD). The UE is provided with a list of CBD RS by candidateBeamRSList.

[0067] Steps 702 and 704 are performed at the UE 705. Once a new beam is identified, the UE 705 sends a beam failure recovery request (BFRQ) 706 to the associated gNB 710. In response, the gNB 710 sends a beam failure recovery response (BFRR) 708, and the BFR procedure 700 is complete.

[0068] As shown in FIG. 6, the UE 602 is configured to receive PDSCHs 610 and 612 from both the TRP#1 620 and the TRP#2 622, and the TRP configured to transmit the PDCCH 640 by upper layer signaling is called the TRP#1 620. FIG. 8 is a diagram 800 in which a user equipment (UE) simultaneously receives PDSCHs (physical downlink shared channels) 610 and 612 from a first TRP (TRP#1) 620 and a second TRP (TRP#2) 622, respectively. The UE 602 is configured to simultaneously receive the PDSCHs 610 and 612 from the TRP#1 620 and the TRP#2 622 during the operation time (T_state02) 802 according to two TCI states 810 shown by the TCI code point 820.

[0069] FIG. 9 is a diagram 900 showing the operation time lengths of beam failure detection (BFD) 910 and new beam candidate detection (CBD) 920 in the BFR procedure. The UE utilizes measurement effort and power consumption to evaluate the BFD and / or CBD regarding the TRP#2, while the performance is not improved when the operation time length 802 is not longer than the required BFD evaluation time 910 and / or CBD evaluation time 920. The BFD evaluation time 910 (T_evaluate_BFD) and CBD evaluation time 920 (T_evaluate_CBD) required by the UE are defined in section 8.5.3 of 38.133 and section 5.17 of 38.321, respectively.

[0070] According to this embodiment, during operation, the UE receives signals from the M-TRP and includes a circuit that performs BFR from two or more M-TRPs by (a) evaluating BFD and CBD for signals including a PDCCH (physical downlink control channel) from at least a first TRP, and (b) skipping the evaluation of one or both of BFD and CBD according to one or more operating conditions. In this way, the UE reduces measurement effort and power consumption. Furthermore, the adoption of measurement effort and power consumption by the UE within the network realizes the flexibility of M-TRP URLLC.

[0071] To evaluate the BFD of two or more M-TRPs, multiple sets of BFD reference signals (BFD-RS) may be explicitly or implicitly configured for the UE, and each set is configured for each of the multiple TRPs (i.e., a BFD-RS set for each TRP). In the explicit method, the BFD-RS set for each TRP can be configured as a set of periodic channel state information reference signals (CSI-RS) or synchronization signal blocks (SSB). In the implicit method, the BFD-RS set for each TRP can be implicitly configured as a quasi co-location (QCL) reference signal of the corresponding CORESET of that TRP based on its TCI state. Similarly, to evaluate the CBD of two or more M-TRPs, multiple sets of CBD reference signals (CBD-RS) (or NBI reference signals (NBI-RS)) can be explicitly or implicitly configured for each TRP. It should be understood that such independent configuration of the BFD-RS set for each TRP and / or the CBD-RS set for each TRP is applicable throughout all embodiments.

[0072] By setting up independent BFD-RS sets for each TRP, if a failure is identified in the BFD-RS set from one of the multiple TRPs (i.e., if a failure is identified in one beam of the multiple TRPs), the beam failure recovery procedure for this specific TRP can be triggered. This can be regarded as partial or TRP-specific beam failure recovery. Compared with the use case scenario that triggers the beam failure recovery procedure only when a failure is identified in all BFD-RS sets set for all TRPs (or if a failure is identified in all beams of all TRPs), it is beneficial in that it can reduce the overall delay of beam failure recovery and improve the transmission efficiency of multi-TRP / panel.

[0073] Furthermore, there may be several other BFR parameters set based on the TRP level. For example, assume that two TRPs (e.g., TRP#1 and TRP#2) are in operation. Therefore, two sets of thresholds such as the BFD threshold (Q_out) and the CBD threshold (Q_in), two sets of timers such as the BFD timer and the BFR timer, and the maximum numbers of two sets of beam failure instance (BFI) counters and their corresponding BFI indications (BFII) can be set independently for TRP#1 and TRP#2 respectively.

[0074] Figure 10 shows the first BFR procedure according to the present disclosure. As shown in Figure 9, the first BFR procedure queues off the operating time duration. Also, TRP#1 620 is one of the M-TRPs that transmit PDCCH 640 by upper layer signaling.

[0075] First, the UE receives (1002) configuration parameters that at least include a notification (e.g., T_state02 802) indicating an appropriate operating time duration of TRP#2 622 from upper layer signaling from the M-TRP (i.e., on the PDCCH 640 from TRP#1 620). The appropriate operating time duration can be a static value of the network (e.g., T_state02 can be defined based on a value obtained by adding an offset to the operating time duration of TRP#1 620), or can be dynamically determined by the network based on realistic environmental conditions or network configurations. An example of dynamically calculating the appropriate operating time using at least DCI, MAC CE, or RRC signaling is shown in Equation (1).

Number

[0076] The offset may be the active time or delay of TRP#2 (if any).

[0077] Furthermore, different from the above description, T_state02 may be set as an operating time duration or window in which both of the two TCI states are activated, or both TRP#1 and TRP#2 are activated during operation.

[0078] Next, the UE performs beam failure detection and recovery defined in Rel-15 / 16 for TRP#1 by performing BFD 1004 and CBD 1006 for TRP#1.

[0079] Specifically, the UE continuously monitors the set of BFD-RS configured for TRP#1 to detect beam failures (1004). If the link-level quality of all corresponding BFD-RS resources exceeds a threshold at a certain point in time (this BFD threshold Q_out is defined as the level at which the downlink radio link cannot be reliably received and corresponds to the block error rate outage (BLER_out) of virtual PDCCH transmission), a BFI can be identified. The physical layer (PHY) provides a BFI notification to the MAC (Media Access Control) layer. The BFD procedure 1004 in the MAC is directed by a timer and a counter that calculates the number of BFIIs. The timer is restarted every time a BFII is received, and when the timer expires, the counter is reset. On the other hand, when N max consecutive (beamFailureInstanceMaxCount) BFIIs are detected, the UE can declare that a beam failure has occurred for TRP#1. Subsequently, the CBD 1006 of TRP#1 is triggered. The UE monitors the link-level quality of a set of CBD-RS (e.g., a set of CSI-RS or SSB) to re-establish connectivity. The UE measures the L1 reference signal received power (L1-RSRP: reference signal received power) for a plurality of CBD-RS reference signals. When the measured value of L1-RSRP exceeds a predetermined value, a new beam can be identified.

[0080] The UE can skip or execute the evaluation of BFD and / or CBD based on the value of T_state02. If the UE determines that T_state02 is less than or equal to the time for evaluating the BFD of TRP#2 (e.g., T_evaluate_BFD 910 in FIG. 9) (1008), the UE skips both the BFD and the CBD (1010). If the UE determines that T_state02 is greater than T_evaluate_BFD (1008), the UE executes the BFD for TRP#2 (1012). Next, the UE compares the time duration of T_state02 with T_evaluate_CBD 920 to determine whether T_state02 is less than T_evaluate_CBD (1014). If the UE determines that T_state02 is less than or equal to the time for evaluating the CBD of TRP#2 (e.g., T_evaluate_CBD 920) (1014), the UE skips the CBD (1016). If the UE determines that T_state02 is greater than T_evaluate_CBD (1014), the UE executes the CBD for TRP#2 (1018).

[0081] When executing the BFD for TRP#2 (1012), similar to TRP#1, the UE maxIt is necessary to detect multiple consecutive BFIIs, and then it can be declared that a beam blockage has occurred based on the BFD-RS set of TRP#2. Next, the evaluation of CBD is triggered (1018), and the UE measures link-level quality such as the L1 reference signal received power (L1-RSRP) regarding the reference signal of the CBD-RS set of TRP#2. In this way, the BFD procedure (1012) of TRP#2 in the MAC layer indicated by the timer and counter is set independently compared to TRP#1. In step 1020, the UE declares a beam blockage event if a beam blockage of TRP#1 and / or TRP#2 is identified during BFRQ (step 706 in FIG. 7). Regarding TRP#2, if CBD is skipped, no action or new beam information due to no action as the default operation is reported. The UE reports beam blockage content including (a) beam blockage (BF) information of TRP#1 and / or TRP#2, (b) new beam information of TRP#1 (if any), and (c) new beam information for TRP#2, no action, or no new beam information due to no action (if any). Then, the UE receives BFRR from the network that provides the corresponding beam from TRP#1 and / or TRP#2 (1022).

[0082] The BFRQ generated in step 1020 may include beam blockage information for each TRP where the blockage occurred, such as the beam blockage index, TRP index, or configuration index of the corresponding TRP. The BFRQ transmitted in step 1020 also includes reporting content for TRP#1 and / or TRP#2 and is reported to the network via at least the UCI (uplink control information) message, MAC CE (medium access control layer control element) message, or RRC (radio resource control) message.

[0083] In this way, when the UE detects beam blockage of any TRP from a plurality of TRPs (here, for example, when TRP#2 has a fault), the UE can send a BFRQ containing the beam blockage information and new beam information of the faulty TRP to the operating TRP#1. Then, the operating TRP#1 can forward the BFRQ to the faulty TRP#2 via the backhaul. This is because the backhaul can have the latest available uplink resources for carrying the BFRQ. In other words, the BFRQ procedure for M-TRP operation should be transmitted via a link with good channel conditions. When the backhaul is optimal, i.e., when the delay of the backhaul meets the requirements or is assumed to be close to zero, the BFR procedure can function well. When the backhaul is not optimal, or when the new beam information of the faulty TRP#2 is not reported by the UE, the operating TRP#1 can decide to instruct the UE to switch from the multi-TRP operation mode to the single-TRP operation mode. This situation occurs when the delay of the backhaul is not suitable for the delay requirement of the BFR procedure set by the BFR timer, or when there is a possibility that the UE cannot reach the faulty TRP#2 due to being completely blocked. The TRP that transmits the PDCCH at a higher level can be set based on the RRC configuration. For example, assuming that two TRPs (TRP A and TRP B) are operating, in the first RRC configuration, TRP A may be set to transmit the PDCCH, so TRP A becomes the primary TRP or TRP#1, and TRP B becomes TRP#2. Also, in the second RRC configuration, TRP B may be set to transmit the PDCCH, in which case TRP B becomes the primary TRP or TRP#1, and TRP A becomes TRP#2. In this way, the flexibility of M-TRP URLLC operation can be realized.

[0084] In addition, the upper-layer parameters can be used to configure multiple TRPs to operate under the carrier aggregation (CA) framework. Specifically, it can be configured such that TRP A operates as a primary cell (PCell) or a primary TRP, and TRP B operates as a secondary cell (SCell) or a secondary TRP. In this way, either the BFR procedure proposed in this embodiment or Rel-16 BFR for multiple SCell with some extensions can be used.

[0085] Furthermore, to transmit the BFRQs of two TRPs, namely TRP#1 and TRP#2, up to two separate scheduling request (SR) settings can be allocated, each including a separate PUCCH resource (i.e., an SR-PUCCH resource). When a single common SR-PUCCH resource is allocated to both TRP#1 and TRP#2, if a failure occurs in either TRP, the UE can transmit the BFRQ of the failed TRP to the operating TRP based on this common SR-PUCCH resource. When two separate SR-PUCCH#1 and SR-PUCCH#2 are allocated to TRP#1 and TRP#2 respectively, if a failure occurs in TRP#2, the UE can transmit the BFRQ information of TRP#2 to the operating TRP#1 based on one of the allocated SR-PUCCH#1 and SR-PUCCH#2 resources. When more than three TRPs are operating, the multiple TRPs can be grouped into multiple groups, and an SR-PUCCH resource for transmitting BFRQ information can be allocated to each group. For example, if there are two TRP groups, with the first group including the primary TRP (or TRP#1) and the second group including the remaining TRPs (or secondary TRPs), the resources of SR-PUCCH#1 and SR-PUCCH#2 can be allocated to the first group and the second group respectively. However, as described above, a common SR-PUCCH resource may also be allocated to both groups for transmitting BFRQ information. This may be determined according to the network implementation or the provisions pre-set in the specification.

[0086] As shown in FIG. 8, the UE is configured to simultaneously receive an independent PDSCH 610 from TRP#1 and an independent PDSCH 612 from TRP#2 within the time of T_state02. FIG. 11 shows a second BFR procedure according to the present disclosure. First, the network sets parameters to transmit PDSCH from up to two TRPs (for example, TRP#1 and TRP#2) (1102). As seen in FIG. 10, the UE always performs both BFD and CBD for TRP#1. To assist the UE in saving power, the network determines whether the UE performs either or both of BFD and CBD for TRP#2 and sends an explicit notification to the UE.

[0087] The network first determines whether T_state02 is less than or equal to T_evaluate_BFD (1104) to determine whether the UE performs either or both of BFD and CBD for TRP#2. If T_state02 is greater than T_evaluate_BFD (1104), the network sets the parameter BFDTRP2 to enable (1106), indicating that the UE performs normal BFD / BFR for TRP#2. If T_state02 is less than or equal to T_evaluate_BFD (1104), the network sets the parameter BFDTRP2 to disable (1108), indicating that the UE does not perform either BFD or CBD for TRP#2.

[0088] Next, the network determines whether T_state02 is less than or equal to T_evaluate_CBD (1110). If T_state02 is greater than T_evaluate_CBD (1110), the network sets the parameter CBDTRP2 to enable (1112), indicating that the UE performs normal CBD for TRP#2. If T_state02 is less than or equal to T_evaluate_CBD (1110), the network sets the parameter CBDTRP2 to disable (1114), indicating that the UE does not perform CBD for TRP#2.

[0089] The decision criteria for steps 1104 and 1110 depend on the implementation of the gNB, and other criteria may be used. Then, the network transmits parameters BFDTRP2 and CBDTRP2, and the UE receives them (1116). The values of BFDTRP2 and CBDTRP2 can be set and updated by using at least DCI, MAC CE, or RRC signaling.

[0090] Also, the parameters of BFD and / or CBD can be implicitly set for the UE by the interpretation of the notification for setting the BFD-RS and / or NBI-RS sets. Here, as an example, assume that two sets of BFD-RS and two sets of CBD-RS are set for TRP#1 and TRP#2. The UE implicitly understands that it needs to perform the evaluation of BFD and CBD for both TRP#1 and TRP#2.

[0091] Next, similar to the procedures of BFD (1004) and CBD (1006) respectively, the UE performs BFD (1118) and CBD (1120) for TRP#1, thereby performing beam failure detection and recovery as defined in Rel-15 / 16 for TPR#1. The UE performs beam failure detection and recovery for TRP#2 according to the value of BFDTRP2 (1122) and the value of CBDTRP2 (1124). In step 1122, if the value of BFDTRP2 is "disable", the BFD action for TRP#2 is not performed; otherwise, BFD is performed for TRP#2. In step 1124, if the value of CBDTRP2 is "disable", the CBD action for TRP#2 is not performed; otherwise, CBD is performed for TRP#2.

[0092] If the UE identifies a beam obstruction of TRP#1 and / or TRP#2 during the BFRQ, it declares a BF event (1126). The UE reports BF content that may include the BF information of TRP#1 and / or TRP#2, the new beam information of TRP#1 (if any), and / or the new beam information for TRP#2, no action, or no new beam information due to no action (if any). Finally, in step 1128, the network generates and transmits a BFRR that includes the corresponding beam information from TRP#1 and / or TRP#2.

[0093] In this way, the network reduces the number of RSs for the UE by not setting the reference signal (RS) for BFD and / or CBD and by not transmitting T_state02 to the UE. Furthermore, the UE reduces the measurement effort and power consumption.

[0094] Since the operation in Figure 11 includes an explicit notification from the network determined for the TRP, the specific conditions based on the explicit notification from the network described above can be extended to three or more TRPs. That is, BFDTRP (disable / enable) and / or CBDTRP (disable / enable) can be determined individually for each TRP and sent to the UE for use in the corresponding TRP. Alternatively, a common BFDTRP value (i.e., disable / enable) and / or a common CBDTRP value (i.e., disable / enable) can be notified to all TRPs respectively.

[0095] Other operating conditions that enable reducing the measurement effort and power consumption of the UE according to the present disclosure are to define a new timer value (i.e., the active operating time length T_state02) for each individual TRP. The new timer is set for the UE. In this way, the TRP is activated for communication with the UE via the TCI state activation MAC CE and deactivated either when the UE receives the TCI state deactivation MAC CE or when the timer expires. The timer value is notified to the UE by using at least DCI (for each TCI state), MAC CE, or RRC signaling.

[0096] Since BFD and CBD for TRP#1 are always executed, the timer value for TRP#1 is set as a symbol value such as infinity so that timer-based deactivation does not occur. For TRP#2, the timer value (T_state02) is set as a finite value (i.e., TRP#2 becomes active based on a request). Since the timer value is finite, the evaluation of BFD / CBD for TRP#2 can be skipped as follows. When T_state02≤T_evaluate_BFD, the UE skips BFD and CBD. When T_state02>T_evaluate_BFD and T_state02≤T_evaluate_CBD, the UE executes BFD and skips CBD.

[0097] When the beam obstruction of TRP#2 is identified, it is reported that there is no action or no new beam information due to no action as the default operation. This enables further realization of the flexibility of M-TRP URLLC operation and reduces the measurement effort and power consumption of the UE. Furthermore, since TRP#2 is deactivated in response to the expiration of the timer, an explicit deactivation for TRP#2 (i.e., the TCI state deactivation MAC CE) is unnecessary.

[0098] The network uses one DCI for N maxis enabled to support the transmission of individual TRPs. N max is a value set (in advance) in the network specification. For high-level solutions, the evaluation of BFD and CBD is the maximum number of TRPs that the UE can be associated with, N UE and is skipped based on a flexible value of N UE The value of N is notified by using at least DCI, MAC CE, or RRC signaling.

[0099] N max >N UE If so, (N max -N UE ) the evaluation of BFD and CBD for individual TRPs is skipped. N UE The list of values of N can be selected according to set rules such as the list of TRPs with the strongest RSRP, ascending / descending order of indices, or other rules. N UE Since the set value of N depends on the UE capabilities, N UE the value of N is flexible, thereby realizing the flexibility of M-TRP URLLC operation and reducing the measurement effort and power consumption of the UE.

[0100] In another high-level solution, the evaluation of BFD and CBD is skipped based on a (pre-)fixed value of N min N is the number of TRPs that need to be evaluated by the UE. N min >N max If so, (N min ) the evaluation of BFD and CBD for (N max -N min ) individual TRPs is skipped. N min The list of N can be selected according to (pre-)set rules such as the list of TRPs with the strongest RSRP, ascending / descending order of indices, or other rules. N min By setting the value of N in this way, network-wide consistency is provided. Furthermore, N min since only the BFD and CBD of individual TRPs need to be evaluated, the BFD measurement effort of the UE can be reduced.

[0101] In addition, in the flowcharts of FIGS. 10 and 11 and their descriptions, as well as the description of timer setting, two TRP scenarios were discussed. However, the method proposed there is also directly applicable to the scenario of N TRPs (i.e., T_stateN, BFDTPRN, and CBDTRPN for supporting URLLC transmission of N TRPs using one DCI). The value of N can be (pre-)set by using at least DCI, MAC CE, or RRC signaling according to the UE capability, or can be notified flexibly.

[0102] Also, the description here focuses on the scenario of M-TRP transmission based on one DCI. However, the method discussed is applicable to the scenario of M-TRP transmission based on multiple DCIs with some modifications. In particular, the evaluation of BFD and / or CBD for each individual TRP can be skipped according to specific conditions based on one or a combination of (a) the operation time length for each individual TRP, (b) an explicit notification from the network, (c) timer setting (the active time length for each individual TRP), (d) UE capability, and (e) the minimum number of TRPs.

[0103] Thus, it can be seen that the exemplary embodiments provide a plurality of mechanisms for realizing the flexibility of M-TRP URLLC operation and reducing the measurement effort and power consumption of the UE.

[0104] The present disclosure can be implemented by software, hardware, or software in conjunction with hardware. Each functional block used in the description of each of the above embodiments can be partially or entirely implemented by LSI (Large Scale Integration) such as an integrated circuit, and each process described in each embodiment may be partially or entirely controlled by the same LSI or a combination of LSIs. The LSI may be formed as an individual chip, or alternatively, one chip may be formed to include part or all of the functional blocks. The LSI may include data input / output coupled thereto. Here, depending on the degree of integration, the LSI may be referred to as an IC, a system LSI, a super LSI, or an ultra LSI. However, the technology for implementing the integrated circuit is not limited to LSI and may be implemented using an application specific circuit, a general-purpose processor, or a processor for a specific application. Further, an FPGA (Field Programmable Gate Array) that can be programmed after manufacturing of an LSI or a reconfigurable processor in which the connection and setting of circuit cells arranged inside the LSI are reconfigurable may be used. The present disclosure can be implemented as digital processing or analog processing. As a result of the progress of semiconductor technology and other derivative technologies, when future integrated circuit technology replaces LSI, the functional blocks can be integrated using future integrated circuit technology. Biotechnology can also be applied.

[0105] The present disclosure can be implemented by any type of device, apparatus, or system having a communication function, referred to as a communication device. The communication device may have a transceiver and a processing / control circuit. The transceiver may have and / or function as 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. The processing / control circuit may include a power management circuit that may include instructions for power management control as either an application specific circuit, a processor, and instructions stored in firmware or a memory provided in the processor.

[0106] Some non-limiting examples of such communication devices include telephones (e.g., mobile (cell) phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital still / video cameras), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, remote health / telemedicine devices, and vehicles that provide communication functions (e.g., automobiles, airplanes, ships), as well as various combinations thereof.

[0107] The communication device is not limited to being portable or mobile, and may include any type of device, apparatus, or system that is non-portable or fixed, such as smart home devices (e.g., home appliances, lighting, smart meters, control panels), vending machines, and any other "things" in the network of the "Internet of Things (IoT)".

[0108] Communication may include, for example, exchanging data via cellular systems, wireless LAN systems, satellite systems, etc., and various combinations thereof. The communication device may include a device such as a controller or sensor coupled to a communication device that performs the communication functions described in the present disclosure. For example, the communication device may include a controller or sensor that generates a control signal or data signal used by a communication device that performs the communication functions of the communication device.

[0109] The communication device may also include an infrastructure facility such as a base station, access point, etc., and any other device, apparatus, or system that communicates or controls with a device such as those in the above non-limiting examples.

[0110] Although exemplary embodiments have been shown in the foregoing detailed description of the present invention, it should be understood that there are a vast number of variations. Furthermore, it should be understood that these embodiments are merely exemplary and are not intended to limit the scope, applicability, operation, or configuration of the present disclosure in any way. Rather, the foregoing detailed description provides a useful roadmap for those skilled in the art to implement the exemplary embodiments, and various changes can be made to the functions and arrangements of the network and / or UE transceiver devices described in the exemplary embodiments without departing from the spirit of the present disclosure defined in the appended claims.

[0111] 1. During operation, a transceiver unit that receives signals at least via a PDSCH (physical downlink shared channel) from a plurality of transmission and reception points (M-TRP: multiple transmission and reception points) in a network; During operation, a circuit that performs beam failure recovery (BFR) by evaluating beam failure detection (BFD) and candidate new beam detection (CBD) for the signal from a first TRP among the M-TRP. A transceiver device comprising: The signal from the first TRP among the M-TRP includes a signal received via a PDCCH (physical downlink control channel), and the circuit determines to skip the evaluation of one or both of the BFD and the CBD for one or more additional TRPs among the M-TRP according to one or more conditions. A transceiver device.

[0112] 2. The transceiver device according to claim 1, wherein the one or more conditions include the operation time lengths of the one or more additional TRPs among the M-TRP determined by the circuit according to the operation time length for performing BFR for the signals from the one or more additional TRPs among the M-TRP.

[0113] 3. The operation time length of the one or more additional TRPs among the M-TRPs is notified using at least one of a DCI (downlink control information) message, a MAC CE (medium access control layer control element) message, or an RRC (radio resource control) message from one of the M-TRPs. The transmitting and receiving apparatus according to claim 2.

[0114] 4. The one or more conditions include the operation time length of the one or more additional TRPs among the M-TRPs determined according to the operation time length and offset value for which the first TRP among the M-TRPs performs BFR. The transmitting and receiving apparatus according to claim 2.

[0115] 5. The one or more conditions include the operation time length of the one or more additional TRPs among the M-TRPs determined by the circuit further according to the PDCCH transmission time. The transmitting and receiving apparatus according to claim 4.

[0116] 6. The circuit skips the evaluation of both the BFD and the CBD of the one or more additional TRPs among the M-TRPs according to the fact that the operation time length of the one or more additional TRPs is not longer than the evaluation time of the BFD. The transmitting and receiving apparatus according to any one of claims 2 to 5.

[0117] 7. The circuit skips the evaluation of the CBD of the one or more additional TRPs among the M-TRPs and performs the evaluation of the BFD according to the fact that the operation time length of the one or more additional TRPs is longer than the evaluation time of the BFD and not longer than the evaluation time of the CBD. The transmitting and receiving apparatus according to any one of claims 2 to 5.

[0118] 8. The transceiver declares a beam failure event and transmits a Beam Failure Recovery Request (BFRQ) to one or more of the M-TRPs. The BFRQ identifies one or more of the beam failure (BF) events and reports content including BF information and CBD information to one or more of the M-TRPs. For each of the M-TRPs, the BF information includes a beam failure index, a TRP index, or a configuration index, and the CBD information includes corresponding new beam information (if any) and default information if there is no new beam information. The transceiver according to any one of claims 1 to 7.

[0119] 9. The circuit declares a beam failure event and generates report content on beam failure for one or more of the M-TRPs. The transceiver transmits the report content to the network via at least one of a UCI (uplink control information) message, a MAC CE (medium access control layer control element) message, or an RRC (radio resource control) message. The transceiver according to any one of claims 1 to 8.

[0120] 10. The report content generated by the circuit includes beam failure information (if identified) for one or more of the additional TRPs of the M-TRP and CBD information. The CBD information is composed of new beam information (if any) of the first TRP of the M-TRPs and default information if there is no new beam information for the one or more additional TRPs of the M-TRP. The transceiver according to claim 9.

[0121] 11. The one or more conditions further include the operating time duration of each independent TRP of the M-TRP. The transceiver according to any one of claims 1 to 10.

[0122] 12. The transmitting and receiving device according to claim 1, wherein the one or more conditions include information received by the transmitting and receiving device.

[0123] 13. The transmitting and receiving device according to claim 12, wherein the information is notified using at least one of a DCI (downlink control information) message, a MAC CE (medium access control layer control element) message, or an RRC (radio resource control) message.

[0124] 14. The information includes BFD parameters and / or CBD parameters corresponding to one or more of the additional TRPs of the M-TRP, and the circuit skips the evaluation of BFD according to the BFD parameters corresponding to one or more of the additional TRPs of the M-TRP, and / or skips the evaluation of CBD according to the CBD parameters corresponding to one or more of the additional TRPs of the M-TRP. The transmitting and receiving device according to claim 12 or 13.

[0125] 15. The one or more conditions include not receiving reference signals for BFD and / or CBD for one or more of the additional TRPs of the M-TRP, and instead receiving the BFD parameters and / or the CBD parameters. The transmitting and receiving device according to claim 14.

[0126] 16. Either or both of the BFD parameters and / or the CBD parameters are notified independently for each of the M-TRPs. The transmitting and receiving device according to claim 14 or 15.

[0127] 17. Either or both of the BFD parameters and / or the CBD parameters are common to all of the M-TRPs. The transmitting and receiving device according to claim 14 or 15.

[0128] 18. The information includes a timer value corresponding to one of the one or more additional TRPs of the M-TRP, and the circuit skips the evaluation of the BFD and / or the CBD for one of the one or more additional TRPs of the M-TRP according to the timer value corresponding to one of the M-TRP. The transceiver device according to claim 12 or 13.

[0129] 19. The timer value includes a finite value, and the transceiver device is deactivated when the timer expires. The transceiver device according to claim 18.

[0130] 20. The information includes a value corresponding to the maximum number of TRPs that the transceiver device can be associated with, and the circuit skips the evaluation of the BFD and / or the CBD for one or more of the M-TRP according to the value corresponding to the maximum number of TRPs that the transceiver device can be associated with. The transceiver device according to claim 12 or 13.

[0131] 21. The information includes a value corresponding to the number of TRPs that need to be evaluated by the transceiver device, and the circuit skips the evaluation of the BFD and / or the CBD for one or more of the M-TRP according to the value corresponding to the number of TRPs that need to be evaluated by the transceiver device. The transceiver device according to claim 12 or 13.

[0132] 22. The list of M-TRPs evaluated by the transceiver device is selected according to a set rule such as a list of TRPs having the strongest RSRP, ascending / descending order of indexes, or the implementation of the transceiver device. The transceiver device according to claim 20 or 21.

[0133] 23. The circuit identifies the first TRP among the M-TRP according to a signal received by PDCCH according to the RRC configuration of the network. The transceiver device according to any one of claims 1 to 22.

[0134] 24. The transmitting and receiving unit receives PDSCH from two or more of the M-TRPs simultaneously, and the PDSCH received from each of the two or more M-TRPs is received on different layers. The transmitting and receiving apparatus according to any one of claims 1 to 23.

[0135] 25. The transmitting and receiving unit receives a signal of M-TRP transmission based on one DCI. The transmitting and receiving apparatus according to any one of claims 1 to 24.

[0136] 26. The transmitting and receiving unit receives signals of M-TRP transmission based on a plurality of DCIs. The transmitting and receiving apparatus according to any one of claims 1 to 24.

[0137] 27. A network including a plurality of transmission and reception points (M-TRP: multiple transmission and reception points) for transmitting and receiving signals, a transmitting and receiving unit that receives signals from one or more of the M-TRPs during operation, and a circuit that performs beam failure recovery (BFR) by evaluating beam failure detection (BFD) and candidate new beam detection (CBD) for the signal from the first TRP among the M-TRPs during operation. A system including a transmitting and receiving apparatus, wherein the network generates one or more values for performing BFD and CBD for one or more of the M-TRPs and transmits the one or more values to the transmitting and receiving apparatus, and the circuit skips the evaluation of one or both of BFD and CBD for one or more additional TRPs among the M-TRPs according to one of the one or more values corresponding to the one or more additional TRPs among the M-TRPs.

[0138] 28. The system according to claim 27, wherein the one or more values corresponding to one or more of the M-TRPs can be notified using at least one of a DCI (downlink control information) message, a MAC CE (medium access control layer control element) message, or an RRC (radio resource control) message.

[0139] 29. The system according to claim 27 or 28, wherein the network generates the one or more values for performing BFD and CBD for one or more of the M-TRPs according to the network implementation.

[0140] 30. The system according to any one of claims 27 to 29, wherein the transceiver receives the signal from one or more of the M-TRPs as an M-TRP transmission based on one DCI.

[0141] 31. The system according to any one of claims 27 to 29, wherein the transceiver receives the signal from one or more of the M-TRPs as an M-TRP transmission based on a plurality of DCIs.

[0142] 32. The system according to claim 31, wherein the one or more values include the operation time length of each independent TRP or the information of each independent TRP received by the transceiver of the transceiver device.

Claims

Claim 1 A transceiver that receives a first set of beam failure detection (BFD) reference signal settings, a second set of BFD reference signal settings, a first set of candidate new beam detection (CBD) reference signal settings, and a second set of CBD reference signal settings, A circuit that performs both a first beam failure detection for a first transceiver point based on the first set of BFD reference signal settings and a candidate new beam detection for the first transceiver point based on the first set of CBD reference signal settings, and performs at least one of a second beam failure detection for a second transceiver point based on the second set of BFD reference signal settings and a candidate new beam detection for the second transceiver point based on the second set of CBD reference signal settings, Comprising, The transceiver transmits a signal including the result of the first beam failure detection and the result of the second beam failure detection to the first transceiver point, A communication device. Claim 2 The first set of BFD reference signal settings, the second set of BFD reference signal settings, the first set of CBD reference signal settings, and the second set of CBD reference signal settings are indicated by Medium Access Control Element (MAC CE) or Radio Resource Control (RRC) signaling, The communication device according to claim 1. Claim 3 The first set and the second set of the BFD reference signal settings, and / or the first set and the second set of the CBD reference signal settings are settings of channel state information (CSI) reference signals or settings of synchronization signal blocks, The communication device according to claim 1. Claim 4 Whether both the beam failure detection based on the first set of BFD reference signal settings and the beam failure detection based on the second set of BFD reference signal settings are performed is determined by a transmission configuration indication (TCI) of downlink control information, The communication device according to claim 1. Claim 5 Transmit a signal including the result of the first beam failure detection related to the first set of BFD reference signal settings or the result of the second beam failure detection related to the second set of BFD reference signal settings, and the result of candidate new beam detection related to the first set of CBD reference signal settings and the result of candidate new beam detection related to the second set of CBD reference signal settings to the first transceiver point. The communication device according to claim 1.

6. A communication device receives a first set of beam failure detection (BFD) reference signal settings, a second set of BFD reference signal settings, a first set of candidate new beam detection (CBD) reference signal settings, and a second set of CBD reference signal settings, performs both a first beam failure detection for the first transceiver point based on the first set of BFD reference signal settings and a candidate new beam detection for the first transceiver point based on the first set of CBD reference signal settings, and performs at least one of a second beam failure detection for the second transceiver point based on the second set of BFD reference signal settings and a candidate new beam detection for the second transceiver point based on the second set of CBD reference signal settings, transmits a signal including the result of the first beam failure detection and the result of the second beam failure detection to the first transceiver point, A communication method.

7. The first set of BFD reference signal settings, the second set of BFD reference signal settings, the first set of CBD reference signal settings, and the second set of CBD reference signal settings are indicated by Medium Access Control Element (MAC CE) or Radio Resource Control (RRC) signaling. The communication method according to claim 6.

8. The first set and the second set of BFD reference signal settings, and / or the first set and the second set of CBD reference signal settings are settings of channel state information (CSI) reference signals or settings of synchronization signal blocks. The communication method according to claim 6.

9. Whether both the beam failure detection based on the first set of the BFD reference signal settings and the beam failure detection based on the second set of the BFD reference signal settings are performed is determined by a transmission configuration indication (TCI) of downlink control information. The communication method according to claim 6.

10. Transmit a signal including the result of the first beam failure detection related to the first set of the BFD reference signal settings or the result of the second beam failure detection related to the second set of the BFD reference signal settings, and the result of the candidate new beam detection related to the first set of the CBD reference signal settings and the result of the candidate new beam detection related to the second set of the CBD reference signal settings to a base station. The communication method according to claim 6.

11. A process of receiving a first set of beam failure detection (BFD) reference signal settings, a second set of BFD reference signal settings, a first set of candidate new beam detection (CBD) reference signal settings, and a second set of CBD reference signal settings; A process of performing both the first beam failure detection related to the first transmission and reception point based on the first set of the BFD reference signal settings and the candidate new beam detection related to the first transmission and reception point based on the first set of the CBD reference signal settings, and performing at least one of the second beam failure detection related to the second transmission and reception point based on the second set of the BFD reference signal settings and the candidate new beam detection related to the second transmission and reception point based on the second set of the CBD reference signal settings; A process of transmitting a signal including the result of the first beam failure detection and the result of the second beam failure detection to the first transmission and reception point; To control; An integrated circuit.

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