WO2024262510A1 - 通信方法及びユーザ装置 - Google Patents

通信方法及びユーザ装置 Download PDF

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Publication number
WO2024262510A1
WO2024262510A1 PCT/JP2024/022147 JP2024022147W WO2024262510A1 WO 2024262510 A1 WO2024262510 A1 WO 2024262510A1 JP 2024022147 W JP2024022147 W JP 2024022147W WO 2024262510 A1 WO2024262510 A1 WO 2024262510A1
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Prior art keywords
multicast
multicast reception
rrc
resume
reception quality
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English (en)
French (fr)
Japanese (ja)
Inventor
真人 藤代
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Kyocera Corp
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Kyocera Corp
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Priority to JP2025528075A priority Critical patent/JPWO2024262510A1/ja
Publication of WO2024262510A1 publication Critical patent/WO2024262510A1/ja
Priority to US19/419,636 priority patent/US20260107345A1/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/40—Connection management for selective distribution or broadcast
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/06—Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/27—Transitions between radio resource control [RRC] states

Definitions

  • This disclosure relates to a communication method and user device for use in a mobile communication system.
  • 3GPP (3rd Generation Partnership Project) (registered trademark; the same applies below) defines the technical specifications for NR (New Radio), a fifth-generation (5G) wireless access technology. Compared to LTE (Long Term Evolution), a fourth-generation (4G) wireless access technology, NR has features such as high speed, large capacity, high reliability, and low latency. 3GPP defines the technical specifications for 5G/NR multicast/broadcast service (MBS).
  • MBS multicast/broadcast service
  • Radio Resource Control In 3GPP Release 17, only user equipment in a Radio Resource Control (RRC) connected state can receive MBS multicast (i.e., multicast reception) (see, for example, Non-Patent Document 1). In contrast, in 3GPP Release 18, the technical specifications are scheduled to be extended so that user equipment in an RRC inactive state can receive multicast.
  • RRC Radio Resource Control
  • the communication method is a communication method executed by a user device in a mobile communication system that provides a multicast/broadcast service (MBS), and includes the steps of: receiving information from a network, which is a condition for initiating RRC connection resume when receiving multicast in a radio resource control (RRC) inactive state, and which is for setting a resume condition related to multicast reception quality; evaluating whether the multicast reception quality satisfies the resume condition when receiving multicast in the RRC inactive state; retaining log information related to the multicast reception based on the fact that the multicast reception quality satisfies the resume condition; and transmitting the log information to the network after transitioning from the RRC inactive state to an RRC connected state.
  • MCS multicast/broadcast service
  • the user device is a user device used in a mobile communication system that provides a multicast/broadcast service (MBS), and includes a receiving unit that receives information from a network, which is a condition for initiating RRC connection resume when receiving multicast in a radio resource control (RRC) inactive state, and is used to set a resume condition related to multicast reception quality; a control unit that evaluates whether the multicast reception quality satisfies the resume condition when receiving multicast in the RRC inactive state, and stores log information related to the multicast reception based on whether the multicast reception quality satisfies the resume condition; and a transmitting unit that transmits the log information to the network after transitioning from the RRC inactive state to an RRC connected state.
  • MCS multicast/broadcast service
  • FIG. 1 is a diagram illustrating a configuration example of a mobile communication system according to an embodiment.
  • FIG. 2 is a diagram illustrating a configuration example of a UE (user equipment) according to an embodiment.
  • FIG. 2 is a diagram for explaining the operation of the mobile communication system according to the embodiment.
  • 1A to 1C are diagrams illustrating an example of a first operation pattern or a second operation pattern of a mobile communication system according to an embodiment.
  • FIG. 11 is a diagram showing an example of a third operation pattern of the mobile communication system according to the embodiment.
  • FIG. 11 is a diagram showing an example of a fourth operation pattern of the mobile communication system according to the embodiment.
  • 3GPP is considering extending the specifications so that a user device receiving multicast data in an RRC inactive state will resume the RRC connection if the reception quality of the multicast data deteriorates below a set threshold. This will allow the user device to spontaneously transition to an RRC connected state by resuming the RRC connection when the quality of service (QoS) required for multicast reception is no longer met, making it easier to meet the QoS required for multicast reception.
  • QoS quality of service
  • the purpose of this disclosure is to make it possible to improve the QoS of MBS.
  • FIG. 1 is a diagram showing a configuration example of a mobile communication system 1 according to an embodiment.
  • the mobile communication system 1 complies with the 3GPP standard 5th generation system (5GS: 5th Generation System).
  • 5GS will be described as an example, but the LTE (Long Term Evolution) system may be applied at least in part to the mobile communication system.
  • the sixth generation (6G) system may be applied at least in part to the mobile communication system.
  • the mobile communication system 1 has a user equipment (UE) 100, a 5G radio access network (NG-RAN: Next Generation Radio Access Network) 10, and a 5G core network (5GC: 5G Core Network) 20.
  • UE user equipment
  • NG-RAN Next Generation Radio Access Network
  • 5GC 5G Core Network
  • the NG-RAN 10 may be simply referred to as the RAN 10.
  • the 5GC 20 may be simply referred to as the core network (CN) 20.
  • the RAN 10 and the CN 20 constitute the network of the mobile communication system 1.
  • UE100 is a mobile wireless communication device.
  • UE100 may be any device that is used by a user.
  • UE100 is a mobile phone terminal (including a smartphone) and/or a tablet terminal, a notebook PC, a communication module (including a communication card or chipset), a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle (Vehicle UE), or an aircraft or a device provided in an aircraft (Aerial UE).
  • NG-RAN10 includes base station (referred to as "gNB” in the 5G system) 200.
  • gNB200 are connected to each other via an Xn interface, which is an interface between base stations.
  • gNB200 manages one or more cells.
  • gNB200 performs wireless communication with UE100 that has established a connection with its own cell.
  • gNB200 has a radio resource management (RRM) function, a routing function for user data (hereinafter simply referred to as “data”), a measurement control function for mobility control and scheduling, etc.
  • RRM radio resource management
  • Cell is used as a term indicating the smallest unit of a wireless communication area.
  • Cell is also used as a term indicating a function or resource for performing wireless communication with UE100.
  • One cell belongs to one carrier frequency (hereinafter simply referred to as "frequency").
  • gNBs can also be connected to the Evolved Packet Core (EPC), which is the core network of LTE.
  • EPC Evolved Packet Core
  • LTE base stations can also be connected to 5GC.
  • LTE base stations and gNBs can also be connected via a base station-to-base station interface.
  • 5GC20 includes AMF (Access and Mobility Management Function) and UPF (User Plane Function) 300.
  • AMF performs various mobility controls for UE100.
  • AMF manages the mobility of UE100 by communicating with UE100 using NAS (Non-Access Stratum) signaling.
  • UPF controls data forwarding.
  • AMF and UPF are connected to gNB200 via the NG interface, which is an interface between a base station and a core network.
  • FIG. 2 is a diagram showing an example of the configuration of a UE 100 (user equipment) according to an embodiment.
  • the UE 100 has a receiving unit 110, a transmitting unit 120, and a control unit 130.
  • the receiving unit 110 and the transmitting unit 120 constitute a wireless communication unit that performs wireless communication with the gNB 200.
  • the receiving unit 110 performs various types of reception under the control of the control unit 130.
  • the receiving unit 110 includes an antenna and a receiver.
  • the receiver converts the radio signal received by the antenna into a baseband signal (received signal) and outputs it to the control unit 130.
  • the transmitting unit 120 performs various transmissions under the control of the control unit 130.
  • the transmitting unit 120 includes an antenna and a transmitter.
  • the transmitter converts the baseband signal (transmission signal) output by the control unit 130 into a radio signal and transmits it from the antenna.
  • the control unit 130 performs various controls and processes in the UE 100. Such processes include the processes of each layer described below. The operations of the UE 100 described above and below may be operations under the control of the control unit 230.
  • the control unit 130 includes at least one processor and at least one memory.
  • the memory stores programs executed by the processor and information used in the processing by the processor.
  • the processor may include a baseband processor and a CPU (Central Processing Unit).
  • the baseband processor performs modulation/demodulation and encoding/decoding of baseband signals.
  • the CPU executes programs stored in the memory to perform various processes.
  • the UE 100 may also have a positioning unit, such as a Global Navigation Satellite System (GNSS) receiver, for acquiring location information indicating the geographical position (latitude, longitude, altitude) of the UE 100.
  • GNSS Global Navigation Satellite System
  • FIG. 3 is a diagram showing an example of the configuration of a gNB 200 (base station) according to an embodiment.
  • the gNB 200 has a transmitting unit 210, a receiving unit 220, a control unit 230, and a backhaul communication unit 240.
  • the transmitting unit 210 and the receiving unit 220 constitute a wireless communication unit that performs wireless communication with the UE 100.
  • the backhaul communication unit 240 constitutes a network communication unit that performs communication with the CN 20.
  • the transmitting unit 210 performs various transmissions under the control of the control unit 230.
  • the transmitting unit 210 includes an antenna and a transmitter.
  • the transmitter converts the baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna.
  • the receiving unit 220 performs various types of reception under the control of the control unit 230.
  • the receiving unit 220 includes an antenna and a receiver.
  • the receiver converts the radio signal received by the antenna into a baseband signal (received signal) and outputs it to the control unit 230.
  • the control unit 230 performs various controls and processes in the gNB 200. Such processes include the processes of each layer described below.
  • the operations of the gNB 200 described above and below may be operations under the control of the control unit 230.
  • the control unit 230 includes at least one processor and at least one memory.
  • the memory stores programs executed by the processor and information used in the processing by the processor.
  • the processor may include a baseband processor and a CPU.
  • the baseband processor performs modulation/demodulation and encoding/decoding of baseband signals.
  • the CPU executes programs stored in the memory to perform various processes.
  • the backhaul communication unit 240 is connected to adjacent base stations via an Xn interface, which is an interface between base stations.
  • the backhaul communication unit 240 is connected to the AMF/UPF 300 via an NG interface, which is an interface between a base station and a core network.
  • the gNB 200 may be composed of a CU (Central Unit) and a DU (Distributed Unit) (i.e., functionally divided), and the two units may be connected via an F1 interface, which is a fronthaul interface.
  • Figure 4 shows the protocol stack configuration of the wireless interface of the user plane that handles data.
  • the user plane radio interface protocol has a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer.
  • PHY physical
  • MAC medium access control
  • RLC radio link control
  • PDCP packet data convergence protocol
  • SDAP service data adaptation protocol
  • the PHY layer performs encoding/decoding, modulation/demodulation, antenna mapping/demapping, and resource mapping/demapping.
  • Data and control information are transmitted between the PHY layer of UE100 and the PHY layer of gNB200 via a physical channel.
  • the PHY layer of UE100 receives downlink control information (DCI) transmitted from gNB200 on a physical downlink control channel (PDCCH).
  • DCI downlink control information
  • PDCCH physical downlink control channel
  • RNTI radio network temporary identifier
  • the DCI transmitted from gNB200 has CRC parity bits scrambled by the RNTI added.
  • the MAC layer performs data priority control, retransmission processing using Hybrid Automatic Repeat reQuest (HARQ), and random access procedures. Data and control information are transmitted between the MAC layer of UE100 and the MAC layer of gNB200 via a transport channel.
  • the MAC layer of gNB200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be assigned to UE100.
  • MCS modulation and coding scheme
  • the RLC layer uses the functions of the MAC layer and PHY layer to transmit data to the RLC layer on the receiving side. Data and control information are transmitted between the RLC layer of UE100 and the RLC layer of gNB200 via logical channels.
  • the PDCP layer performs header compression/decompression, encryption/decryption, etc.
  • the SDAP layer maps IP flows, which are the units for which the core network controls QoS (Quality of Service), to radio bearers, which are the units for which the AS (Access Stratum) controls QoS. Note that if the RAN is connected to the EPC, SDAP is not necessary.
  • Figure 5 shows the configuration of the protocol stack for the wireless interface of the control plane that handles signaling (control signals).
  • the protocol stack of the radio interface of the control plane has an RRC (Radio Resource Control) layer and a NAS (Non-Access Stratum) layer instead of the SDAP layer shown in Figure 4.
  • RRC Radio Resource Control
  • NAS Non-Access Stratum
  • RRC signaling for various settings is transmitted between the RRC layer of UE100 and the RRC layer of gNB200.
  • the RRC layer controls logical channels, transport channels, and physical channels in response to the establishment, re-establishment, and release of radio bearers.
  • RRC connection connection between the RRC of UE100 and the RRC of gNB200
  • UE100 is in an RRC connected state.
  • RRC connection no connection between the RRC of UE100 and the RRC of gNB200
  • UE100 is in an RRC idle state.
  • UE100 is in an RRC inactive state.
  • the NAS layer (also simply referred to as "NAS") located above the RRC layer performs session management, mobility management, etc.
  • NAS signaling is transmitted between the NAS layer of UE100 and the NAS layer of AMF300A.
  • UE100 also has an application layer, etc.
  • AS layer also simply referred to as "AS”
  • the mobile communication system 1 can perform resource-efficient distribution by using a multicast/broadcast service (MBS).
  • MBS multicast/broadcast service
  • MBS Broadcast In the case of a broadcast communication service (also referred to as "MBS Broadcast"), the same service and the same specific content data are provided simultaneously to all UEs 100 in a geographical area. That is, all UEs 100 in the broadcast service area are allowed to receive the data.
  • the broadcast communication service is delivered to the UEs 100 using a broadcast session, which is a type of MBS session.
  • the UEs 100 can receive the broadcast session in any of the following states: RRC idle state, RRC inactive state, and RRC connected state.
  • the MBS session can be identified by an MBS session ID (e.g., TMGI (Temporary Mobile Group Identity)).
  • Point-to-Multipoint (PTM) delivery is applied to the broadcast communication service.
  • the gNB 200 delivers a single copy of an MBS packet to a set (group) of multiple UEs 100.
  • the gNB 200 schedules a group-common PDSCH scrambled by the G-RNTI (Group RNTI), which is a group-common RNTI, using a group-common PDCCH having a CRC (Cyclic Redundancy Code) scrambled by the G-RNTI.
  • G-RNTI Group RNTI
  • CRC Cyclic Redundancy Code
  • the UE 100 receives a broadcast session in the following procedure.
  • SIB20 system information block type 20
  • the SIB20 includes a configuration of a multicast control channel (MCCH), which is a type of logical channel.
  • MCCH multicast control channel
  • the UE 100 receives the MCCH from the gNB 200 based on the SIB20.
  • the MCCH includes a PTM configuration.
  • the PTM configuration transmits a configuration for a multicast traffic channel (MTCH), which is a type of logical channel, and a broadcast MRB, which is a multicast radio bearer (MRB) for the broadcast session.
  • MTCH multicast traffic channel
  • MRB multicast radio bearer
  • the information transmitted by the MCCH is sometimes referred to as MBS broadcast control information.
  • the UE 100 receives the MTCH based on the MCCH.
  • the MTCH transmits the broadcast session (specifically, the MBS data belonging to the broadcast session).
  • the MCCH is a PTM downlink channel for transmitting MBS broadcast control information associated with one or more MTCHs from the network 10 to the UE 100.
  • the MTCH is a PTM downlink channel for transmitting MBS data of either a multicast session or a broadcast session from the network 10 to the UE 100.
  • MBS Multicast In the case of a multicast communication service (also called "MBS multicast"), the same service and the same specific content data are provided simultaneously to a specific set of UEs, i.e., not all UEs 100 within a multicast service area are allowed to receive the data.
  • the multicast communication service is delivered to the UEs 100 using a multicast session, which is a type of MBS session.
  • UE 100 can receive a multicast session only after joining the multicast session.
  • Joining a multicast session may mean being registered in network 5 (CN 20) as UE 100 capable of receiving the multicast session.
  • 3GPP Release 17 In the case of multicast communication services, in 3GPP Release 17, only UEs 100 in an RRC connected state can receive multicast sessions. On the other hand, in 3GPP Release 18, this is expected to be expanded so that UEs 100 in an RRC inactive state can also receive multicast sessions.
  • Multicast Reception in RRC Connected State UE 100 in the RRC connected state can receive a multicast session (specifically, MBS data belonging to a multicast session) using mechanisms such as PTP (Point-to-Point) and/or PTM (Point-to-Multipoint) delivery.
  • a multicast session specifically, MBS data belonging to a multicast session
  • PTP Point-to-Point
  • PTM Point-to-Multipoint
  • UE100 in an RRC connected state receives a multicast session in the following procedure.
  • UE100 receives an RRC Reconfiguration message from gNB200.
  • the RRC Reconfiguration message is a message transmitted on a Dedicated Control Channel (DCCH).
  • the RRC Reconfiguration message transmits settings regarding the MTCH for receiving a multicast session and settings of the multicast MRB, which is the MRB for the multicast session.
  • UE100 receives the MTCH based on the RRC Reconfiguration message.
  • the MTCH transmits the multicast session (specifically, the MBS data belonging to the multicast session).
  • the settings related to MTCH are settings related to MTCH reception, and include at least one of the following: group identifier (G-RNTI), discontinuous reception settings (DRX settings or scheduling information: MTCH transmission ON time, MTCH transmission period, reference time and time offset, HARQ retransmission settings), Layer 2 settings (PDCP settings, RLC settings), and physical channel settings (PDCCH settings, PDSCH settings, SSB mapping settings).
  • G-RNTI group identifier
  • DRX settings or scheduling information MTCH transmission ON time, MTCH transmission period, reference time and time offset, HARQ retransmission settings
  • Layer 2 settings PDCP settings, RLC settings
  • PDCCH settings Physical channel settings
  • PDSCH settings SSB mapping settings
  • the UE 100 in the RRC inactive state can receive a multicast session (specifically, MBS data belonging to a multicast session) by using a PTM distribution mechanism.
  • a multicast session specifically, MBS data belonging to a multicast session
  • the UE 100 in the RRC inactive state can receive a multicast session in the following procedure.
  • the UE 100 in the RRC inactive state receives a newly introduced system information block (also referred to as a "new SIB") from the gNB 200.
  • the new SIB includes a setting for a newly introduced MCCH (also referred to as a "multicast MCCH").
  • the UE 100 in the RRC inactive state receives a multicast MCCH from the gNB 200 based on the new SIB.
  • the multicast MCCH includes a PTM setting.
  • the PTM setting transmits a setting related to the MTCH for receiving the multicast session and a setting for the multicast MRB, which is an MRB for the multicast session.
  • the UE 100 in the RRC inactive state receives the MTCH based on the multicast MCCH.
  • the MTCH transmits the multicast session (specifically, the MBS data belonging to the multicast session).
  • gNB200 When gNB200 configures UE100 to receive multicast in the RRC inactive state, it can send PTM settings to UE100 using an RRC Release message including suspend settings. In this case, when UE100 receives an RRC Release message including PTM settings from gNB200, it transitions to the RRC inactive state and receives the multicast session in the RRC inactive state.
  • the load on network 5 and UE100 can be reduced compared to when multicast reception is performed in the RRC connected state.
  • FIG. 6 is a diagram for explaining the operation of the mobile communication system 1 according to the embodiment.
  • gNB 200 transmits a resume condition setting for setting a resume condition to UE 100.
  • UE 100 receives the resume condition setting from gNB 200.
  • gNB 200 transmits the resume condition setting to UE 100 in an RRC connected state by dedicated signaling, for example, an RRC Release message or an RRC Reconfiguration message.
  • gNB 200 may transmit the resume condition setting to UE 100 by broadcast signaling, for example, an MCCH or SIB, for UE 100 in an RRC connected state or an RRC inactive state.
  • the resume condition includes a threshold value that is compared with the reception quality of the multicast data.
  • the reception quality of the multicast data may be at least one of RSRP (Reference Signals Received Power), RSRQ (Reference Signal Received Quality), SINR (Signal-to-interference-plus-noise ratio), BER (Bit Error Rate), BLER (Block Error Rate), and PER (Packet Error Rate).
  • RSRP Reference Signals Received Power
  • RSRQ Reference Signal Received Quality
  • SINR Signal-to-interference-plus-noise ratio
  • BER Bit Error Rate
  • BLER Block Error Rate
  • PER Packet Error Rate
  • These reception qualities are preferably reception qualities for the MTCH carrying the multicast session (i.e., the reception quality of the multicast data).
  • the resume condition may be set for UE100 for each multicast session (for each MBS session ID).
  • UE 100 in an RRC inactive state receives a multicast session (multicast data) from gNB 200 on MTCH.
  • UE100 transitions to an RRC inactive state by receiving an RRC Release message including a suspend setting from gNB200 after receiving the RRC Reconfiguration message, and performs multicast reception in the RRC inactive state.
  • the resume condition setting is transmitted from gNB200 to UE100 in an RRC Release message
  • UE100 transitions to an RRC inactive state by receiving an RRC Release message from gNB200, and performs multicast reception in the RRC inactive state.
  • UE100 performing multicast reception in the RRC inactive state measures the reception quality of the multicast data (also referred to as "multicast reception quality") and evaluates whether the multicast reception quality satisfies the resume condition.
  • the resume condition is set as an RSRP threshold, an RSRQ threshold, or an SINR threshold, if the multicast reception quality (RSRP, RSRQ, or SINR) falls below the threshold, UE100 considers that the multicast reception quality has deteriorated below the threshold, and determines that the multicast reception quality satisfies the resume condition.
  • the resume condition is set as a BER threshold, a BLER threshold, or a PER threshold
  • the multicast reception quality (BER, BLER, or PER) exceeds the threshold
  • the UE 100 considers that the multicast reception quality has deteriorated below the threshold, and determines that the multicast reception quality satisfies the resume condition.
  • UE100 in the RRC inactive state starts RRC connection resume in response to determining that the multicast reception quality satisfies the resume condition. Specifically, UE100 transmits an RRC resume request message to gNB200 (current serving cell).
  • gNB200 normally accepts the RRC Resume Request message and transmits an RRC Resume message to UE100.
  • UE100 resumes the RRC connection in response to receiving the RRC Resume message, and transitions from the RRC inactive state to the RRC connected state.
  • UE100 in the RRC connected state can use link adaptation and retransmission control, and can perform high-quality multicast reception.
  • UE 100 can spontaneously transition to the RRC connected state by resuming the RRC connection, making it easier to satisfy the QoS required for multicast reception.
  • network 5 cannot grasp the situation when the QoS required for multicast reception is no longer satisfied, making it difficult to perform network optimization to prevent the recurrence of such an event.
  • the following operation allows the network 5 to grasp the situation when the QoS required for multicast reception is no longer met, making it possible to improve the QoS of the MBS.
  • UE100 receives information (resume condition setting) from network 5 (gNB200) that is a condition for initiating RRC connection resume when receiving multicast in an RRC inactive state and is for setting a resume condition related to multicast reception quality.
  • Network 5 (gNB200) may transmit to UE100 setting information on whether or not log information related to multicast reception should be retained together with the resume condition setting.
  • UE100 may retain log information only when it is configured to retain log information. Alternatively, UE100 may voluntarily retain log information based on the fact that multicast reception quality satisfies the resume condition, even without such an explicit setting.
  • UE100 when UE100 performs multicast reception in the RRC inactive state, it evaluates whether the multicast reception quality satisfies the resume condition.
  • UE 100 retains log information related to multicast reception based on the fact that the multicast reception quality satisfies the resume condition.
  • First movement pattern The UE 100 holds the log information when the multicast reception quality satisfies the resume condition.
  • Second movement pattern The UE 100 holds the log information when starting the RRC connection resume after the multicast reception quality satisfies the resume condition.
  • the UE 100 holds the log information when the RRC connection resume is successful after the multicast reception quality satisfies the resume condition.
  • the UE 100 holds log information when the RRC connection resume fails after the multicast reception quality satisfies the resume condition.
  • the log information includes at least one of the following items of information 1) to 7): 1) Measurement results of multicast reception quality; 2) identification information for identifying the resume condition that was satisfied; 3) Session identification information for identifying a multicast session whose multicast reception quality satisfies the resume condition; 4) Cell identification information for identifying a serving cell of UE 100 when the multicast reception quality satisfies the resume condition; 5) Location information for identifying the geographical location of the UE 100 when the multicast reception quality satisfies the resume condition; 6) Time information for identifying the timing at which the multicast reception quality satisfies the resume condition; 7) Identification information for identifying whether the RRC connection resume has failed or succeeded.
  • UE100 After UE100 transitions from the RRC inactive state to the RRC connected state, it transmits log information to network 5 (gNB200).
  • FIG. 7 is a diagram showing an example of the first operation pattern or the second operation pattern of the mobile communication system 1 according to the embodiment.
  • step S101 gNB200 sets resume conditions in UE100.
  • UE100 receives information (resume condition setting) from gNB200, which is a condition for starting RRC connection resume when receiving multicast in the RRC inactive state and is for setting resume conditions related to multicast reception quality.
  • step S102 UE 100 receives a multicast session in the RRC inactive state.
  • UE 100 measures the multicast reception quality, and when performing multicast reception in the RRC inactive state, evaluates whether the multicast reception quality satisfies the resume condition.
  • step S104 UE100 retains log information related to multicast reception. Furthermore, UE100 starts RRC connection resume. UE100 may retain log information before starting RRC connection resume. UE100 may retain log information when starting RRC connection resume.
  • UE100 may include in the log information, for example, the multicast reception quality (RSRP, RSRQ, SINR, BER, BLER, PER) measured in step S102.
  • UE100 may include in the log information only those items of these reception quality indicators (RSRP, RSRQ, SINR, BER, BLER, PER) for which a threshold is set in the resume condition.
  • UE100 may include all items in the log information. If multiple resume conditions (multiple thresholds) are set in UE100, UE100 may include in the log information cause information indicating which resume condition (which threshold) was satisfied. For example, if the cause is that RSRP fell below the threshold, UE100 records that fact.
  • UE100 may include in the log information the MBS session ID of the multicast session being received in the RRC inactive state.
  • UE100 may include in the log information only the MBS session ID of the multicast session that satisfies the resume condition.
  • UE100 may include in the log information the MBS session ID of each of the multiple multicast sessions.
  • UE100 may include in the log information a cell ID indicating the serving cell of UE100 when the multicast reception quality satisfies the resume condition.
  • UE100 may include location information indicating the geographical location of UE100 when the multicast reception quality satisfies the resume condition in the log information.
  • time information e.g., a timestamp
  • time information e.g., a timestamp
  • step S105 UE100 transitions to the RRC connected state by resuming the RRC connection.
  • step S106 UE100 transmits the retained log information to network 5 (gNB200). For example, UE100 transmits a log retention indication (Availability Indication) indicating that the log information is being retained to network 5. After transmitting the log retention indication, UE100 transmits a message (UE Information Response) including the retained log information to network 5 in response to receiving a log transmission request (UE Information Request) from network 5.
  • Availability Indication a log retention indication
  • UE100 transmits a message (UE Information Response) including the retained log information to network 5 in response to receiving a log transmission request (UE Information Request) from network 5.
  • the network 5 may identify the location and situation of the problem based on the log information from the UE 100, and optimize the coverage area.
  • the network 5 may change the resume condition (threshold) set for the UE 100 based on the log information from the UE 100.
  • the network 5 may transition other UEs 100 receiving multicast in the RRC inactive state to the RRC connected state by paging (RAN Paging) based on the log information from the UE 100.
  • RAN Paging paging
  • FIG. 8 is a diagram showing an example of a third operation pattern of the mobile communication system 1 according to the embodiment. Here, differences from the operation in FIG. 7 are explained.
  • steps S201 to S203 are the same as those in FIG. 7.
  • step S203 If UE100 determines that the multicast reception quality satisfies the resume condition (step S203: YES), it starts RRC connection resume in step S204.
  • step S205 UE100 determines whether the RRC connection resume has been successful. For example, if UE100 receives an RRC Resume Request message from gNB200 after transmitting an RRC Resume Request message to gNB200, UE100 determines that the RRC connection resume has been successful; otherwise, UE100 determines that the RRC connection resume has failed.
  • step S206 the UE 100 retains the log information as described above.
  • the UE 100 may include in the log information information indicating that the RRC connection resume has been successful due to the multicast reception quality satisfying the resume condition.
  • step S207 UE100 transitions to the RRC connected state by resuming the RRC connection.
  • step S208 UE100 transmits the log information it holds to network 5 (gNB200).
  • FIG. 9 is a diagram showing an example of a fourth operation pattern of the mobile communication system 1 according to the embodiment. Here, differences from the operations in FIGS. 7 and 8 are described.
  • steps S301 to S303 are the same as those in Figures 7 and 8.
  • step S303 If UE100 determines that the multicast reception quality satisfies the resume condition (step S303: YES), it starts RRC connection resume in step S304.
  • step S305 UE100 determines whether or not the RRC connection resume was successful.
  • step S306 the UE 100 transitions to the RRC connected state. Then, in step S307, if the UE 100 holds log information, it transmits the log information to the network 5 (gNB 200).
  • step S308 UE 100 retains the log information as described above.
  • UE 100 may include information indicating that the RRC connection resume has failed due to the multicast reception quality satisfying the resume condition in the log information. Thereafter, UE 100 continues to retain the log information.
  • UE 100 may transmit the retained log information to network 5.
  • the resume condition may be set from the gNB 200 to the UE 100 in association with each of the serving cell and the neighboring cell.
  • the UE 100 may perform RRC resume only when these two resume conditions are satisfied, and may not perform RRC resume otherwise.
  • the RSRP threshold is set as the resume condition, if the RSRP of the serving cell falls below the threshold and the RSRP of the neighboring cell falls below the threshold, the RRC resume is performed. Note that different values may be set for these RSRP thresholds.
  • the combination of the two resume conditions may be a set that targets the serving cell and all neighboring cells, or a different combination may be set for each neighboring cell.
  • multicast reception in the RRC inactive state has been mainly described, but the operation according to the above embodiment may be applied to multicast reception in the RRC idle state.
  • the above-mentioned RRC resume is replaced with RRC establishment.
  • Each of the above-mentioned operation flows can be implemented not only separately but also by combining two or more operation flows. For example, some steps of one operation flow can be added to another operation flow, or some steps of one operation flow can be replaced with some steps of another operation flow. In each flow, it is not necessary to execute all steps, and only some of the steps can be executed.
  • the base station is an NR base station (gNB)
  • the base station may be an LTE base station (eNB) or a 6G base station.
  • the base station may also be a relay node such as an IAB (Integrated Access and Backhaul) node.
  • the base station may be a DU of an IAB node.
  • the UE 100 may also be an MT (Mobile Termination) of an IAB node.
  • UE100 may be a terminal function unit (a type of communication module) that allows a base station to control a repeater that relays signals.
  • a terminal function unit is called an MT.
  • Examples of MT include, in addition to IAB-MT, NCR (Network Controlled Repeater)-MT and RIS (Reconfigurable Intelligent Surface)-MT.
  • network node primarily refers to a base station, but may also refer to a core network device or part of a base station (CU, DU, or RU).
  • a network node may also be composed of a combination of at least a part of a core network device and at least a part of a base station.
  • a program may be provided that causes a computer to execute each process performed by UE100 or gNB200.
  • the program may be recorded on a computer-readable medium.
  • the computer-readable medium on which the program is recorded may be a non-transient recording medium.
  • the non-transient recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.
  • circuits that execute each process performed by UE100 or gNB200 may be integrated, and at least a part of UE100 or gNB200 may be configured as a semiconductor integrated circuit (chip set, SoC: System on a chip).
  • UE100 or gNB200 network node
  • a processor includes transistors and other circuits and is considered to be circuitry or processing circuitry.
  • a processor may be a programmed processor that executes a program stored in a memory.
  • circuitry, unit, and means are hardware that is programmed to realize the described functions or hardware that executes them.
  • the hardware may be any hardware disclosed herein or any hardware known to be programmed or capable of performing the described functions. If the hardware is a processor considered to be a type of circuitry, the circuitry, means, or unit is a combination of hardware and software used to configure the hardware and/or processor.
  • the terms “based on” and “depending on/in response to” do not mean “based only on” or “only in response to,” unless otherwise specified.
  • the term “based on” means both “based only on” and “based at least in part on.”
  • the term “in response to” means both “only in response to” and “at least in part on.”
  • the terms “include,” “comprise,” and variations thereof do not mean including only the items listed, but may include only the items listed, or may include additional items in addition to the items listed.
  • the term “or” as used in this disclosure is not intended to mean an exclusive or.
  • any reference to elements using designations such as “first,” “second,” etc., as used in this disclosure is not intended to generally limit the quantity or order of those elements. These designations may be used herein as a convenient way to distinguish between two or more elements. Thus, a reference to a first and second element does not imply that only two elements may be employed therein, or that the first element must precede the second element in some manner.
  • articles are added by translation such as, for example, a, an, and the in English, these articles are intended to include the plural unless the context clearly indicates otherwise.
  • RRC radio resource control
  • a user equipment for use in a mobile communication system providing a multicast/broadcast service comprising: A receiving unit that receives, from a network, information for setting a condition for initiating RRC connection resume during multicast reception in a radio resource control (RRC) inactive state and for setting a resume condition related to multicast reception quality; a control unit that evaluates whether the multicast reception quality satisfies the resume condition when multicast reception is performed in the RRC inactive state, and stores log information related to the multicast reception based on whether the multicast reception quality satisfies the resume condition; a transmitter configured to transmit the log information to the network after transitioning from the RRC inactive state to an RRC connected state.
  • RRC radio resource control
  • Mobile communication system 5 Network 10: RAN 20: C.N. 100: UE (user equipment) 110: Receiving unit 120: Transmitting unit 130: Control unit 200: gNB (base station) 210: Transmitter 220: Receiver 230: Controller 240: Backhaul Communication Unit

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016509814A (ja) * 2013-02-14 2016-03-31 エルジー エレクトロニクス インコーポレイティド 無線通信システムにおけるｍｂｍｓ情報報告方法及びそれをサポートする装置
WO2023014683A1 (en) * 2021-08-03 2023-02-09 Idac Holdings, Inc. Multicast and broadcast services reliability indication
US20230164636A1 (en) * 2021-11-22 2023-05-25 Parsa Wireless Communications Llc Mbs configuration optimization based on quality of experience feedback

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016509814A (ja) * 2013-02-14 2016-03-31 エルジー エレクトロニクス インコーポレイティド 無線通信システムにおけるｍｂｍｓ情報報告方法及びそれをサポートする装置
WO2023014683A1 (en) * 2021-08-03 2023-02-09 Idac Holdings, Inc. Multicast and broadcast services reliability indication
US20230164636A1 (en) * 2021-11-22 2023-05-25 Parsa Wireless Communications Llc Mbs configuration optimization based on quality of experience feedback

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