WO2024113951A1 - Systèmes et procédés pour prendre en charge une réception de multidiffusion dans un état rrc_inactive - Google Patents

Systèmes et procédés pour prendre en charge une réception de multidiffusion dans un état rrc_inactive Download PDF

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Publication number
WO2024113951A1
WO2024113951A1 PCT/CN2023/112257 CN2023112257W WO2024113951A1 WO 2024113951 A1 WO2024113951 A1 WO 2024113951A1 CN 2023112257 W CN2023112257 W CN 2023112257W WO 2024113951 A1 WO2024113951 A1 WO 2024113951A1
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WIPO (PCT)
Prior art keywords
rrc
inactive state
configuration
wireless communication
session
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PCT/CN2023/112257
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English (en)
Inventor
Yang Li
Tao Qi
Lin Chen
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Zte Corporation
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Priority to PCT/CN2023/112257 priority Critical patent/WO2024113951A1/fr
Publication of WO2024113951A1 publication Critical patent/WO2024113951A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/20—Control channels or signalling for resource management
    • H04W72/23—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal
    • H04W72/231—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal the control data signalling from the layers above the physical layer, e.g. RRC or MAC-CE signalling

Definitions

  • the disclosure relates generally to wireless communications, including but not limited to systems and methods for supporting multicast reception in RRC_INACTIVE state.
  • the standardization organization Third Generation Partnership Project (3GPP) is currently in the process of specifying a new Radio Interface called 5G New Radio (5G NR) as well as a Next Generation Packet Core Network (NG-CN or NGC) .
  • the 5G NR will have three main components: a 5G Access Network (5G-AN) , a 5G Core Network (5GC) , and a User Equipment (UE) .
  • 5G-AN 5G Access Network
  • 5GC 5G Core Network
  • UE User Equipment
  • the elements of the 5GC also called Network Functions, have been simplified with some of them being software based, and some being hardware based, so that they could be adapted according to need.
  • example embodiments disclosed herein are directed to solving the issues relating to one or more of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings.
  • example systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and are not limiting, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments (e.g., including various combinations of features/elements across different examples/embodiments/implementations) can be made while remaining within the scope of this disclosure.
  • At least one aspect is directed to a system, method, apparatus, or a computer-readable medium of the following. At least one aspect is directed to a system, method, apparatus, or a computer-readable medium of the following.
  • a centralized unit (CU) of a wireless communication node e.g., a base station (BS)
  • BS base station
  • the first signaling may include information about multicast reception in RRC_INACTIVE state of at least a first wireless communication device (e.g., a user equipment (UE) ) .
  • the first signaling can be for the first wireless communication device (e.g., per UE or specific to the UE) .
  • the first signaling may comprise at least one of: indication information indicating that the first wireless communication device is to be configured for the multicast reception in RRC_INACTIVE state; a cause value, indicating that a reason for releasing the first wireless communication device to RRC_INACTIVE state is that the first wireless communication device is configured to receive multicast in RRC_INACTIVE state; point-to-multipoint (PTM) configuration information, which can be used for the multicast reception in RRC_INACTIVE state; or indication information.
  • the PTM configuration information may include PTM configuration of a lower layer (or any one or more specific layers) ; an identifier (ID) of a cell, is contained in the indication information.
  • the identifier (ID) of the cell may indicate which cell the configuration applies to.
  • the identifier (ID) of the cell may indicate which cell is configured for the multicast reception in RRC_INACTIVE state.
  • the PTM configuration information can be for a session (e.g., per session or specific to a session) .
  • the indication information may indicate that PTM configuration used in RRC_CONNECTED state is to continue to be used in RRC_INACTIVE state.
  • the indication information may indicate that the PTM configuration to be used in RRC_INACTIVE state is to be obtained/received via a multicast-broadcast service control channel (MCCH) .
  • the indication information can be for (e.g., specifically for) the session.
  • the CU may determine, according to the second signaling, to release the first wireless communication device to RRC_INACTIVE state.
  • the CU may send, to the first wireless communication device, a RRCRelease message including the indication information indicating the PTM configuration to be used in RRC_INACTIVE state.
  • a control plane of the CU e.g., CU-CP
  • the CU may send a confirm message for the multicast reception in RRC_INACTIVE state to the DU.
  • the confirm message may include first indication information indicating that corresponding multicast sessions are to be received in RRC_INACTIVE state in a certain cell.
  • the confirm message can be for the first wireless communication device.
  • the first signaling can be for a session.
  • the information may comprise (an indication of) at least one of: indication information indicating that the session is to be configured for the multicast reception in RRC_INACTIVE state; a list of wireless communication devices joined this session that are to be released to RRC_INACTIVE state for multicast reception; a list of cells that are to be triggered for multicast reception in RRC_INACTIVE state; a list of PTM configurations that are to be used in RRC_INACTIVE state; a list of indication information indicating that the PTM configurations to be used in RRC_CONNECTED state are to continue to be used in RRC_INACTIVE state; or a list of indication information indicating the PTM configurations to be used in RRC_INACTIVE state are to be obtained via a multicast-broadcast service control channel (MCCH) .
  • MCCH multicast-broadcast service control channel
  • the CU may determine, according to the first signaling, to release the first wireless communication device to RRC_INACTIVE state.
  • the CU may send, to the first wireless communication device, a RRCRelease message including the indication information indicating the PTM configuration to be used in RRC_INACTIVE state.
  • a control plane of the CU may send, to a user plane of the CU, the information about multicast reception in RRC_INACTIVE state, in an E1 signaling for the session.
  • the first signaling can be regarding interface management.
  • the information may comprise (an indication of) at least one of: a list of wireless communication devices that are to be released to RRC_INACTIVE state for multicast reception; an indication of resource usage for the first wireless communication device, the indication included in the list of wireless communication devices; a list of cells that are to be triggered for multicast reception in RRC_INACTIVE state; or a list of multicast sessions that are to be received in RRC_INACTIVE state.
  • the CU may determine, according to the first signaling, to release the first wireless communication device to RRC_INACTIVE state.
  • the CU may send, to the first wireless communication device, a RRCRelease message including the indication information indicating the PTM configuration to be used in RRC_INACTIVE state.
  • a control plane of the CU may send, to a user plane of the CU, the information about multicast reception in RRC_INACTIVE state, in an E1 signaling for a session.
  • the CU may incorporate/insert/include/carry/send the PTM configuration in the RRCRelease message. If the second signaling includes the indication information indicating that the PTM configuration used in RRC_CONNECTED state is to continue to be used in RRC_INACTIVE state, the CU may incorporate/insert/include/carry/send the indication information indicating that the PTM configuration used in RRC_CONNECTED state is to continue to be used in RRC_INACTIVE state in the RRCRelease message.
  • the CU may incorporate/insert/include/carry the indication information indicating that the PTM configuration used in RRC_INACTIVE state in the RRCRelease message.
  • the CU may incorporate/insert/include/carry/send, in the RRCRelease message, a first indication for the session, to indicate whether the wireless communication device is to (or can) monitor for a group radio network temporary identifier (G-RNTI) immediately after transitioning to RRC_INACTIVE state.
  • G-RNTI group radio network temporary identifier
  • the CU may incorporate/insert/include/carry/send, in the RRCRelease message, an identifier (ID) of a cell in the PTM configuration information.
  • ID identifier
  • the first indication may indicate whether a session state is inactive or active. If the session state is active, the wireless communication device is to (or can) monitor for the G-RNTI for multicast reception immediately after transitioning to RRC_INACTIVE state. If the session state is inactive, the first wireless communication device is not to (or cannot) monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the first indication may indicate the PTM configuration, the PTM configuration comprising at least one of: a pre-configuration which is used upon session activation, or an ongoing-configuration which is used to receive a corresponding active session immediately after transitioning to RRC_INACTIVE state. If the PTM configuration comprises the pre-configuration, the first wireless communication device is to (or can) store the pre-configuration and not use the pre-configuration to monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state. If the PTM configuration comprises the ongoing-configuration, the first wireless communication device is to (or can) use the ongoing-configuration to monitor for the G-RNTI immediately after transitioning to RRC_INACTIVE state.
  • the first indication may indicate a behavior of the first wireless communication device in RRC_INACTIVE state.
  • the behavior may include that the first wireless communication device is to (or can) monitor for the G-RNTI (e.g., immediately) after transitioning to the RRC_INACTIVE state.
  • the behavior may include that the first wireless communication device is not to (or may not) monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the CU may send, to the first wireless communication device, a RRCRelease message comprising a first indication for a session, the first indication to indicate whether the wireless communication device is to (or can) monitor for a group radio network temporary identifier (G-RNTI) immediately after transitioning to RRC_INACTIVE state.
  • the first indication may indicate whether a session state is inactive or active. If the session state is active, the wireless communication device is to (or can) monitor for the G-RNTI for multicast reception after transitioning to RRC_INACTIVE state. If the session state is inactive, the first wireless communication device is not to (or may not) monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the first indication may indicate a point-to-multipoint (PTM) configuration, the PTM configuration comprising at least one of: a pre-configuration which is used upon session activation, or an ongoing-configuration in which starts monitoring the session immediately after transitioning to RRC_INACTIVE state.
  • PTM configuration comprises the pre-configuration
  • the first wireless communication device is to (or can) store the pre-configuration and/or not use the pre-configuration to monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the PTM configuration comprises the ongoing-configuration
  • the first wireless communication device is to (or can) use the ongoing-configuration to monitor for the G-RNTI immediately after transitioning to RRC_INACTIVE state.
  • the first indication may indicate a behavior of the first wireless communication device in RRC_INACTIVE state.
  • the behavior may include that the first wireless communication device is to (or can) monitor for the G-RNTI immediately after transitioning to the RRC_INACTIVE state.
  • the behavior may include that the first wireless communication device is not to (or may not) monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the CU may incorporate/insert/include/carry/send, in the RRCRelease message, an identifier (ID) of a cell in the PTM configuration information.
  • ID an identifier
  • a control plane of the CU may send, to a user plane of the CU, at least one of session state or configuration state, in an E1 signaling for a session.
  • a distributed unit (DU) of a wireless communication node may send a first signaling to a centralized unit (CU) of the wireless communication node.
  • the first signaling may include information about multicast reception in RRC_INACTIVE state of at least a first wireless communication device.
  • FIG. 1 illustrates an example cellular communication network in which techniques disclosed herein may be implemented, in accordance with an embodiment of the present disclosure
  • FIG. 2 illustrates a block diagram of an example base station and a user equipment device, in accordance with some embodiments of the present disclosure.
  • FIG. 3 illustrates a flow diagram of an example method for supporting multicast reception in RRC_INACTIVE state, in accordance with an embodiment of the present disclosure.
  • FIG. 1 illustrates an example wireless communication network, and/or system, 100 in which techniques disclosed herein may be implemented, in accordance with an embodiment of the present disclosure.
  • the wireless communication network 100 may be any wireless network, such as a cellular network or a narrowband Internet of things (NB-IoT) network, and is herein referred to as “network 100.
  • NB-IoT narrowband Internet of things
  • Such an example network 100 includes a base station 102 (hereinafter “BS 102” ; also referred to as wireless communication node) and a user equipment device 104 (hereinafter “UE 104” ; also referred to as wireless communication device) that can communicate with each other via a communication link 110 (e.g., a wireless communication channel) , and a cluster of cells 126, 130, 132, 134, 136, 138 and 140 overlaying a geographical area 101.
  • the BS 102 and UE 104 are contained within a respective geographic boundary of cell 126.
  • Each of the other cells 130, 132, 134, 136, 138 and 140 may include at least one base station operating at its allocated bandwidth to provide adequate radio coverage to its intended users.
  • the BS 102 may operate at an allocated channel transmission bandwidth to provide adequate coverage to the UE 104.
  • the BS 102 and the UE 104 may communicate via a downlink radio frame 118, and an uplink radio frame 124 respectively.
  • Each radio frame 118/124 may be further divided into sub-frames 120/127 which may include data symbols 122/128.
  • the BS 102 and UE 104 are described herein as non-limiting examples of “communication nodes, ” generally, which can practice the methods disclosed herein. Such communication nodes may be capable of wireless and/or wired communications, in accordance with various embodiments of the present solution.
  • FIG. 2 illustrates a block diagram of an example wireless communication system 200 for transmitting and receiving wireless communication signals (e.g., OFDM/OFDMA signals) in accordance with some embodiments of the present solution.
  • the system 200 may include components and elements configured to support known or conventional operating features that need not be described in detail herein.
  • system 200 can be used to communicate (e.g., transmit and receive) data symbols in a wireless communication environment such as the wireless communication environment 100 of FIG. 1, as described above.
  • the System 200 generally includes a base station 202 (hereinafter “BS 202” ) and a user equipment device 204 (hereinafter “UE 204” ) .
  • the BS 202 includes a BS (base station) transceiver module 210, a BS antenna 212, a BS processor module 214, a BS memory module 216, and a network communication module 218, each module being coupled and interconnected with one another as necessary via a data communication bus 220.
  • the UE 204 includes a UE (user equipment) transceiver module 230, a UE antenna 232, a UE memory module 234, and a UE processor module 236, each module being coupled and interconnected with one another as necessary via a data communication bus 240.
  • the BS 202 communicates with the UE 204 via a communication channel 250, which can be any wireless channel or other medium suitable for transmission of data as described herein.
  • system 200 may further include any number of modules other than the modules shown in FIG. 2.
  • modules other than the modules shown in FIG. 2.
  • the various illustrative blocks, modules, circuits, and processing logic described in connection with the embodiments disclosed herein may be implemented in hardware, computer-readable software, firmware, or any practical combination thereof.
  • various illustrative components, blocks, modules, circuits, and steps are described generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software can depend upon the particular application and design constraints imposed on the overall system. Those familiar with the concepts described herein may implement such functionality in a suitable manner for each particular application, but such implementation decisions should not be interpreted as limiting the scope of the present disclosure.
  • the UE transceiver 230 may be referred to herein as an "uplink" transceiver 230 that includes a radio frequency (RF) transmitter and a RF receiver each comprising circuitry that is coupled to the antenna 232.
  • a duplex switch (not shown) may alternatively couple the uplink transmitter or receiver to the uplink antenna in time duplex fashion.
  • the BS transceiver 210 may be referred to herein as a "downlink" transceiver 210 that includes a RF transmitter and a RF receiver each comprising circuitry that is coupled to the antenna 212.
  • a downlink duplex switch may alternatively couple the downlink transmitter or receiver to the downlink antenna 212 in time duplex fashion.
  • the operations of the two transceiver modules 210 and 230 may be coordinated in time such that the uplink receiver circuitry is coupled to the uplink antenna 232 for reception of transmissions over the wireless transmission link 250 at the same time that the downlink transmitter is coupled to the downlink antenna 212. Conversely, the operations of the two transceivers 210 and 230 may be coordinated in time such that the downlink receiver is coupled to the downlink antenna 212 for reception of transmissions over the wireless transmission link 250 at the same time that the uplink transmitter is coupled to the uplink antenna 232. In some embodiments, there is close time synchronization with a minimal guard time between changes in duplex direction.
  • the UE transceiver 230 and the base station transceiver 210 are configured to communicate via the wireless data communication link 250, and cooperate with a suitably configured RF antenna arrangement 212/232 that can support a particular wireless communication protocol and modulation scheme.
  • the UE transceiver 210 and the base station transceiver 210 are configured to support industry standards such as the Long Term Evolution (LTE) and emerging 5G standards, and the like. It is understood, however, that the present disclosure is not necessarily limited in application to a particular standard and associated protocols. Rather, the UE transceiver 230 and the base station transceiver 210 may be configured to support alternate, or additional, wireless data communication protocols, including future standards or variations thereof.
  • LTE Long Term Evolution
  • 5G 5G
  • the BS 202 may be an evolved node B (eNB) , a serving eNB, a target eNB, a femto station, or a pico station, for example.
  • eNB evolved node B
  • the UE 204 may be embodied in various types of user devices such as a mobile phone, a smart phone, a personal digital assistant (PDA) , tablet, laptop computer, wearable computing device, etc.
  • PDA personal digital assistant
  • the processor modules 214 and 236 may be implemented, or realized, with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein.
  • a processor may be realized as a microprocessor, a controller, a microcontroller, a state machine, or the like.
  • a processor may also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration.
  • the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in firmware, in a software module executed by processor modules 214 and 236, respectively, or in any practical combination thereof.
  • the memory modules 216 and 234 may be realized as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
  • memory modules 216 and 234 may be coupled to the processor modules 210 and 230, respectively, such that the processors modules 210 and 230 can read information from, and write information to, memory modules 216 and 234, respectively.
  • the memory modules 216 and 234 may also be integrated into their respective processor modules 210 and 230.
  • the memory modules 216 and 234 may each include a cache memory for storing temporary variables or other intermediate information during execution of instructions to be executed by processor modules 210 and 230, respectively.
  • Memory modules 216 and 234 may also each include non-volatile memory for storing instructions to be executed by the processor modules 210 and 230, respectively.
  • the network communication module 218 generally represents the hardware, software, firmware, processing logic, and/or other components of the base station 202 that enable bi-directional communication between base station transceiver 210 and other network components and communication nodes configured to communication with the base station 202.
  • network communication module 218 may be configured to support internet or WiMAX traffic.
  • network communication module 218 provides an 802.3 Ethernet interface such that base station transceiver 210 can communicate with a conventional Ethernet based computer network.
  • the network communication module 218 may include a physical interface for connection to the computer network (e.g., Mobile Switching Center (MSC) ) .
  • MSC Mobile Switching Center
  • the Open Systems Interconnection (OSI) Model (referred to herein as, “open system interconnection model” ) is a conceptual and logical layout that defines network communication used by systems (e.g., wireless communication device, wireless communication node) open to interconnection and communication with other systems.
  • the model is broken into seven subcomponents, or layers, each of which represents a conceptual collection of services provided to the layers above and below it.
  • the OSI Model also defines a logical network and effectively describes computer packet transfer by using different layer protocols.
  • the OSI Model may also be referred to as the seven-layer OSI Model or the seven-layer model.
  • a first layer may be a physical layer.
  • a second layer may be a Medium Access Control (MAC) layer.
  • MAC Medium Access Control
  • a third layer may be a Radio Link Control (RLC) layer.
  • a fourth layer may be a Packet Data Convergence Protocol (PDCP) layer.
  • PDCP Packet Data Convergence Protocol
  • a fifth layer may be a Radio Resource Control (RRC) layer.
  • a sixth layer may be a Non Access Stratum (NAS) layer or an Internet Protocol (IP) layer, and the seventh layer being the other layer.
  • NAS Non Access Stratum
  • IP Internet Protocol
  • Multicast and Broadcast Services can provide reliable, low-latency, and resource-efficient transmission to multiple terminals simultaneously. These services can be used to support an extensive array of applications in crowded areas for instance, including in concerts, sports stadiums, and racing tracks. On one hand, there may be situations where the video may need to be synchronized to a terminal. On the other hand, there may be situations where multiple viewing angles are required/desired/beneficial. Additionally, MBS can facilitate large-scale VR live broadcasts where numerous users in the same cell can watch simultaneously and/or be disseminated essential information simultaneously, such as epidemic and disaster updates in a certain area, through applications or TVs.
  • NR new radio
  • a problem derived from this is how to deal with the issue of cell congestion. Considering that the number of UEs connected to the cell and the volume of services carried by the cell may be limited, the resulting congestion of the cell can lead to service rejection or reduction in the transmission of other services or UEs.
  • the UE may have three RRC states, including RRC_CONNECTED, RRC_IDLE, and RRC_INACTIVE.
  • RRC_INACTIVE is a state defined in 5G NR.
  • the UE may retain part of the context of the access network.
  • the core network side may not know or be aware that the UE has transitioned to RRC_INACTIVE state, that is, the state may be transparent to the core network.
  • the UE may need to transition to the RRC_CONNECTED state through a connection recovery process.
  • the introduction of the RRC_INACTIVE state not only saves energy but also ensures better control plane delay management.
  • the UE can quickly transition to the RRC_CONNECTED state with lower control plane delay as compared to the RRC_IDLE state.
  • One of the solutions to have or continue MBS multicast reception in cell congestion or power saving scenarios may be having state transition to RRC_INACTIVE for some UEs that support or have applied MBS multicast. Such UEs can be transitioned from RRC_CONNECTED state to RRC_INACTIVE state, to receive or continue to receive the multicast session.
  • point-to-multipoint (PTM) configuration delivery methods can be specified as follows: for multicast, a dedicated signaling may be used for multicast; for broadcast, a single cell (SC) -PTM like signaling may be used. For Broadcast reception in a secondary cell (SCell) , a dedicated signaling to deliver system information block (SIBx) may be used. An indication/confirmation to support multicast reception in the RRC_INACTIVE state can be provided in this manner, for example.
  • SIBx system information block
  • An indication/confirmation to support multicast reception in the RRC_INACTIVE state can be provided in this manner, for example.
  • the present disclosure provides solutions on how to enable a UE to receive and/or continue receiving MBS services in RRC_INACTIVE state.
  • Solution 1 Obtain a new PTM configuration from an RRCRelease message.
  • Solution 2 Continue to use a PTM configuration which is used in RRC_CONNECTED state.
  • Solution 3 Obtain an indication from RRCRelease message which indicates a UE to obtain a PTM configuration by monitoring a multicast control channel (MCCH) .
  • MCCH multicast control channel
  • RRC_INACTIVE There may be two states of multicast sessions which are allowed to be received in RRC_INACTIVE: active multicast sessions or inactive multicast sessions.
  • a UE may not monitor a MCCH and/or a MBS Traffic Channel (MTCH) until the corresponding activation indication is received from a gNB.
  • UEs e.g., in RRC_INACTIVE state
  • RRC_INACTIVE state may monitor a MCCH to obtain the updated PTM configuration and can start to receive data immediately.
  • some aspects are disclosed herein, including the content of PTM configuration and how the UE can be informed about the cells where this configuration can be applied.
  • a UE may receive, from a BS, a per session indication which indicates to the UE whether to monitor for a group radio network temporary identifier (G-RNTI) or not, in/using a RRCRelease message.
  • the indication can be a session state, e.g., inactive or active. If the session state is active, the UE may monitor the G-RNTI for multicast reception immediately after transitioning to the RRC_INACTIVE state. If the session state is inactive, the UE may not monitor the G-RNTI until the corresponding activation indication is received from the gNB for instance after transitioning to the RRC_INACTIVE state.
  • the indication may indicate a configuration state.
  • the state (or type) of a PTM configuration can be a pre-configuration which is used upon session activation or an ongoing-configuration in which the UE can start monitoring the session (e.g., immediately) after transitioning to the RRC_INACTIVE state.
  • the PTM configuration is a pre-configuration
  • the UE may store the PTM configuration and can not use the PTM configuration to monitor the G-RNTI for instance until receiving the corresponding activation indication from the gNB after transitioning to RRC_INACTIVE state.
  • the PTM configuration is an ongoing-configuration, the UE may use the PTM configuration to monitor the G-RNTI (e.g., immediately) after transitioning to RRC_INACTIVE state.
  • the indication may indicate a UE behavior in RRC_INACTIVE state.
  • the UE may monitor the G-RNTI (e.g., immediately) after transitioning to the RRC_INACTIVE state or the UE may not monitor the G-RNTI until for instance receiving the corresponding activation indication from the gNB after transitioning to the RRC_INACTIVE state.
  • a UE may receive a cell identifier (ID) in the PTM configuration carried in the RRCRelease message.
  • ID cell identifier
  • Solution 1 Obtain a new PTM configuration from a RRCRelease message.
  • Solution 2 Continue to use a PTM configuration which is used in RRC_CONNECTED.
  • Solution 3 Obtain an indication from RRCRelease message which indicates a UE to obtain PTM configuration by monitoring a MCCH.
  • RRC_INACTIVE state There may be two states of multicast sessions which are allowed to be received in RRC_INACTIVE state: active multicast sessions or inactive multicast sessions.
  • Solution 1 Apply to active multicast sessions and inactive multicast sessions.
  • Solution 2 Apply to active multicast sessions and inactive multicast sessions.
  • Solution 3 Apply (e.g., only) to active multicast sessions.
  • UE behaviors can be different for the two states of multicast sessions, as follows.
  • UE For active sessions, UE (e.g., in RRC_INACTIVE state) may monitor a G-RNTI for multicast reception (e.g., immediately) after transitioning to the RRC_INACTIVE state. If a MCCH exists, the UE may monitor MCCH to obtain/receive the updated PTM configuration. For inactive sessions, RRC_INACTIVE UEs may not monitor the G-RNTI until for instance receiving the corresponding activation indication from the gNB after transitioning to the RRC_INACTIVE state. If a MCCH exists, the UE may not monitor the MCCH until the corresponding activation indication is received from the gNB after transitioning to the RRC_INACTIVE state.
  • a behavior indication may be added per session for inactive multicast sessions in a RRCRelease message. According to this indication, the UE can distinguish that this session is inactive for instance. The UE may not monitor G-RNTI until receiving the corresponding activation indication from the gNB.
  • the content of this behavior indication can include a session state (e.g., inactive or not) , configuration state (e.g., pre-configuration or not) or UE behavior indication (e.g., G-RNTI monitoring or not) .
  • session state e.g., inactive or not
  • configuration state e.g., pre-configuration or not
  • UE behavior indication e.g., G-RNTI monitoring or not
  • Example Solution 1 Continue to use the configuration which is used in RRC_CONNECTED state.
  • the UE may suspend the corresponding PTM configuration used in RRC_CONNECTED state when transitioning to RRC_INACTIVE state. If the configuration used in RRC_CONNECTED and RRC_INACTIVE states are the same, there may be no need to perform configuration suspending and/or reestablishing.
  • the configuration used in RRC_CONNECTED can be indicated that the configuration may be used in RRC_INACTIVE state.
  • the UEs which are ready to receive multicast in RRC_INACTIVE state may be indicated a session state.
  • a behavior indication can be added per session for inactive multicast sessions in the RRCRelease message.
  • the content of this indication may include a session state (e.g., 1 bit in the RRCRelease message) .
  • This indication may indicate the corresponding multicast session is in an inactive state or not.
  • the content of this indication can be/include a configuration state (e.g., 1 bit in RRCRelease message) .
  • This indication may indicate the corresponding configuration is a pre-configuration or not, for the corresponding multicast session.
  • the content of this indication can be a UE behavior indication (e.g., 1 bit in RRCRelease message) . This indication may indicate whether the UE can or is to monitor G-RNTI immediately for the corresponding multicast session or not.
  • the UE may not suspend the PTM configuration for the corresponding MBS multicast session when the UE transitions to RRC_INACTIVE state, and may continue to receive the corresponding MBS multicast data in RRC_INACTIVE using this PTM configuration (e.g., immediately) . If a MCCH exists, the UE may start to monitor MCCH to obtain the updated PTM configuration after transitioning to the RRC_INACTIVE state.
  • the UE may not suspend the corresponding PTM configuration and may not monitor the G-RNTI immediately after transitioning to the RRC_INACTIVE state.
  • the UE may continue to use a previous PTM configuration to receive multicast data when receiving an activation indication from the gNB.
  • the UE may suspend the corresponding PTM configuration and may not monitor the G-RNTI immediately after transitioning to the RRC_INACTIVE state. The UE may resume this configuration to receive corresponding multicast session when receiving an activation indication from the gNB.
  • Example Solution 2 New configuration carried in a RRCRelease message.
  • a new configuration can be carried in a RRCRelease message.
  • the UE behavior may depend on the corresponding multicast session state.
  • UEs which are ready to receive multicast in RRC_INACTIVE can be indicated with a session state.
  • a behavior indication can be added per session for inactive multicast sessions in the RRCRelease message.
  • the content of this indication can be a session state (e.g., 1 bit in RRCRelease message) .
  • This indication may indicate whether the corresponding multicast session is in an inactive state or not.
  • the content of this indication can be a configuration state (e.g., 1 bit in RRCRelease message) .
  • This indication may indicate that the corresponding configuration is a pre-configuration or not, for the corresponding multicast session.
  • the content of this indication can be a UE behavior indication (e.g., 1 bit in RRCRelease message) .
  • This indication indicates that the UE may monitor G-RNTI immediately for the corresponding multicast session or not.
  • the UE may suspend the previous PTM configuration and can establish the new configuration according to the RRCRelease message.
  • the UE may start to monitor for a corresponding G-RNTI (e.g., immediately) after transitioning to RRC_INACTIVE state. If a MCCH exists, the UE may start to monitor MCCH to obtain the updated PTM configuration after transitioning to the RRC_INACTIVE state.
  • a corresponding G-RNTI e.g., immediately
  • the UE may start to monitor MCCH to obtain the updated PTM configuration after transitioning to the RRC_INACTIVE state.
  • the UE may suspend the previous PTM configuration, and may store the new PTM configuration carried in the RRCRelease message.
  • the UE may not monitor corresponding G-RNTI (e.g., immediately) after transitioning to RRC_INACTIVE state.
  • the UE may use the new configuration to receive multicast data in RRC_INACTIVE state when receiving an activation indication from the gNB.
  • the corresponding cell ID may be contained in the PTM configuration which is delivered by the RRCRelease message.
  • the cell ID indicating which cell the new configuration applies to, can be contained in the PTM configuration which is delivered by the RRCRelease message.
  • RRC_INACTIVE can be supported.
  • the impact/approach on F1 signaling is disclosed herein, such as, who can trigger multicast reception in RRC_INACTIVE (e.g., gNB-DU or gNB-CU-CP) .
  • Solution 1 Obtain a new PTM configuration from a RRCRelease message.
  • Solution 2 Continue to use a PTM configuration which is used in RRC_CONNECTED state.
  • Solution 3 Obtain an indication from a RRCRelease message which indicates to the UE to obtain PTM configuration by monitoring a MCCH.
  • the impact on the signaling interaction between gNB-CU and gNB-DU can be discussed, such as who can decide the PTM configuration delivery method (e.g., gNB-DU or gNB-CU-CP) , who can trigger generation of the PTM configuration in the RRCRelease message (e.g., gNB-DU, gNB-CU-CP) .
  • the PTM configuration delivery method e.g., gNB-DU or gNB-CU-CP
  • RRCRelease message e.gNB-DU, gNB-CU-CP
  • a gNB-DU may send information about triggering multicast reception in RRC_INACTIVE by a F1 signaling.
  • the signaling can be per UE.
  • the information may include at least one of:
  • the indication information indicating that the UE is released to RRC_INACTIVE state to receive multicast.
  • the configuration information may include at least lower layer PTM configuration.
  • the configuration information can be per session.
  • the indication information can be per session.
  • the indication information, indicating the PTM configuration used in RRC_INACTIVE can be obtained from MCCH.
  • the indication information can be per session.
  • the cause value, indicating that the reason indicating that a reason for releasing the first wireless communication device to RRC_INACTIVE state is that the first wireless communication device is configured to receive multicast in RRC_INACTIVE state.
  • an identifier (ID) of a cell which indicates which cell is to be triggered for multicast reception in RRC_INACTIVE state, is contained in the indication information.
  • the UE can be released to RRC_INACTIVE state.
  • An indication information indicating that the corresponding multicast sessions can be received in RRC_INACTIVE state in which cell, can be delivered to the DU.
  • the DU may have a requirement to always release the UE to RRC_INACTIVE state.
  • the CU may deliver the indication information about PTM configuration used in RRC_INACTIVE state, in a RRCRelease message.
  • the CU may deliver the PTM configuration to the UE by a RRCRelease message.
  • the CU may deliver the corresponding indication information to the UE by a RRCRelease message.
  • the CU may deliver the corresponding indication information to the UE by RRCRelease message.
  • the signaling can be per session.
  • the information may include at least one of:
  • the resource usage per UE can be included.
  • An indication information list indicating that the PTM configuration used in RRC_CONNECTED can continue to be used in RRC_INACTIVE state.
  • the cell ID indicating which cell the indication applies to, can be
  • An indication information list indicating that the PTM configuration used in RRC_INACTIVE state, can be (or is to be) obtained from a MCCH.
  • the cell ID indicating which cell the indication applies to, can be included in the indication information.
  • the UE may be released to RRC_INACTIVE state.
  • An indication information indicating that the corresponding multicast sessions are received in RRC_INACTIVE in which cells, can be delivered to the DU.
  • the DU may have a requirement to always release the UE to RRC_INACTIVE state.
  • the CU may deliver the indication information about PTM configuration used in RRC_INACTIVE in a RRCRelease message.
  • CU can deliver the PTM configuration to the UE by a RRCRelease message.
  • the CU can deliver the corresponding indication information to the UE by a RRCRelease message.
  • the CU may deliver the corresponding indication information to the UE by a RRCRelease message.
  • the information may include at least one of:
  • a UE list where UEs in this list can be released to RRC_INACTIVE state to receive multicast.
  • the resource usage per UE can be included.
  • a cell list where cells in this list may be triggered to perform/support multicast reception in RRC_INACTIVE.
  • An indication information indicating that the corresponding multicast sessions can be received in RRC_INACTIVE in which cell, can be delivered to the DU.
  • the DU may have a requirement to always release the UE to RRC_INACTIVE state.
  • a gNB-CU-control plane may send information about triggering multicast reception in RRC_INACTIVE state, by/using a F1 signaling (e.g., to the wireless communication device) .
  • the signaling can be per UE.
  • the information may include at least one of:
  • An indication information indicating that the UE is configured to receive multicast in RRC_INACTIVE state.
  • the cell ID which can indicate which cell the configuration applies to, can be included in the indication information.
  • a response message to the gNB-CU-CP which may include at least one of:
  • the PTM configuration information which can be used to receive multicast in the RRC_INACTIVE state.
  • the configuration information may include at least lower layer PTM configuration.
  • the configuration information can be per session.
  • the indication information indicating that the PTM configuration used in RRC_CONNECTED can continue to be used in RRC_INACTIVE.
  • the indication information can be per session.
  • the indication information indicating that the PTM configuration used in RRC_INACTIVE can be obtained from MCCH.
  • the indication information can be per session.
  • the wireless communication device can release the UE to RRC_INACTIVE state.
  • the CU may deliver/send the indication information about PTM configuration used in RRC_INACTIVE state, in RRCRelease message.
  • DU response, if none of the MRBs were established successfully, the CU may not release UE to RRC_INACTIVE state.
  • DU response, if at least one of MRBs were established successfully, the CU may release UE to RRC_INACTIVE state.
  • DU if a lower layer configuration is carried in DU’s response message, the CU may include the lower layer configuration in the RRCRelease message.
  • the CU can deliver the PTM configuration to the UE by/in a RRCRelease message.
  • the CU can deliver the corresponding indication information to the UE by a RRCRelease message.
  • the CU can deliver the corresponding indication information to the UE by/using a RRCRelease message.
  • the signaling can be per session.
  • the information may include at least one of:
  • indication information indicating that the session is to be configured for the multicast reception in RRC_INACTIVE state.
  • a MRB configuration list where MRB configurations in this list can be used in RRC_INACTIVE state.
  • the cell ID indicating which cell the configuration applies to, can be contained in the indication information.
  • response message to gNB-CU-CP may include at least one of:
  • the configuration information may include at least lower layer PTM configuration.
  • the configuration information can be per session.
  • the indication information indicating that the PTM configuration used in RRC_CONNECTED state can continue to be used in RRC_INACTIVE state.
  • the indication information can be per session.
  • the indication information, indicating the PTM configuration used in RRC_INACTIVE state can be obtained from MCCH.
  • the indication information can be per session.
  • the CU may determine to release the UE to RRC_INACTIVE state.
  • the CU may determine to always release the UE to RRC_INACTIVE state.
  • the CU may deliver the indication information about PTM configuration used in RRC_INACTIVE in a RRCRelease message.
  • DU response, if none of the MRBs were established successfully, the CU may not release UE to RRC_INACTIVE state.
  • DU response, if at least one of MRBs were established successfully, the CU may release the UE to RRC_INACTIVE state.
  • DU if a lower layer configuration is carried in DU’s response message, the CU may include the lower layer configuration in a RRCRelease message.
  • the CU may deliver the PTM configuration to the UE by a RRCRelease message.
  • the CU may deliver the corresponding indication information to the UE by a RRCRelease message.
  • the CU may deliver the corresponding indication information to the UE by a RRCRelease message.
  • gNB-DU trigger multicast reception in RRC_INACTIVE
  • a gNB-DU may trigger multicast reception in RRC_INACTIVE.
  • RRC_INACTIVE To address cell congestion caused by a large number of UEs, multicast reception in RRC_INACTIVE can be supported.
  • the impact on F1 signaling is disclosed herein, such as, who can trigger multicast reception in RRC_INACTIVE in CU-DU split scenario (e.g., gNB-DU or gNB-CU-CP) .
  • the gNB-DU can be aware of the resource usage of cells.
  • the gNB-DU may trigger multicast reception in RRC_INACTIVE state.
  • the gNB-DU may send the information about triggering multicast reception in RRC_INACTIVE state by a UE-associated F1 signaling.
  • the example approach (es) can be as follows.
  • ⁇ Define a new UE-associated F1 signaling (gNB-DU initiated/trigger/driven) .
  • an indication information indicating that the UE is (to be) released to RRC_INACTIVE state to receive multicast, can be carried in a UE-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the gNB-DU may send it to the gNB-CU.
  • the PTM configuration which can be used to receive multicast in the RRC_INACTIVE state, can be carried in a UE-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the configuration may include at least lower layer PTM configuration.
  • the configuration can be per session.
  • an indication information indicating that the PTM configuration used in RRC_CONNECTED state can continue to be used in RRC_INACTIVE state, can be carried in a UE-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the indication can be per session.
  • an indication information indicating the PTM configuration used in RRC_INACTIVE state can be obtained from MCCH, can be carried in a UE-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the gNB-CU can consider whether to release UE to RRC_INACTIVE state to receive multicast.
  • Option 1 Accept DU’s suggestion, release UE to RRC_INACTIVE state to receive multicast.
  • Option 2 Reject DU’s suggestion, keep UE in RRC_CONNECTED state to receive multicast.
  • gNB-CU may always release UE to RRC_INACTIVE state to receive multicast.
  • the gNB-CU may deliver the related information about PTM configuration used in RRC_INACTIVE state in a RRCRelease message, in which three example options are provided as follows.
  • the CU can deliver the PTM configuration to the UE by a RRCRelease message.
  • the CU may deliver the corresponding indication information to the UE by a RRCRelease message.
  • the CU may deliver the corresponding indication information to the UE by a RRCRelease message.
  • the gNB-DU may send the information about triggering multicast reception in RRC_INACTIVE by a session-associated F1 signaling.
  • the example forms are as follows.
  • ⁇ Define a new multicast session-associated F1 signaling (gNB-DU initiated) .
  • indication information indicating that the session is to be configured for the multicast reception in RRC_INACTIVE state can be carried in a session-associated F1 signaling from the gNB- DU to the gNB-CU-CP.
  • a cell list where cells in this list are triggered to multicast reception in RRC_INACTIVE, can be carried in a session-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the gNB-DU may send it to gNB-CU.
  • a PTM configuration list where PTM configurations in this list can be used to receive multicast in the RRC_INACTIVE state, can be carried in a session-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the configuration may include at least lower layer PTM configuration.
  • a cell ID indicating which cell the new configuration applies to, can be included in the PTM configuration.
  • an indication information list indicating that the PTM configuration used in RRC_CONNECTED can continue to be used in RRC_INACTIVE, can be carried in a session-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the cell ID indicating which cell the indication applies to, can be included in the indication information.
  • an indication information list indicating that the PTM configuration used in RRC_INACTIVE can be obtained from MCCH, can be carried in a session-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • a cell ID which can indicate which cell the indication applies to, can be included in the indication information.
  • the gNB-CU may consider whether to release the UE to RRC_INACTIVE state to receive multicast. There can be multiple options, such as the following two example options for the gNB-CU.
  • Option 1 Accept DU’s suggestion, release UE to RRC_INACTIVE state to receive multicast.
  • Option 2 Reject DU’s suggestion, keep UE in RRC_CONNECTED state to receive multicast.
  • an indication information indicating that the corresponding multicast sessions are received in RRC_INACTIVE state in which cells, can be delivered to the DU.
  • the gNB-CU may always release the UEs which are in the list to RRC_INACTIVE state to receive multicast.
  • the gNB-CU can deliver the related information about PTM configuration used in a RRC_INACTIVE state, in RRCRelease message, according to one or more of the following options.
  • the CU can deliver the PTM configuration to the UE by a RRCRelease message.
  • the CU can deliver the corresponding indication information to the UE by a RRCRelease message.
  • the CU can deliver the corresponding indication information to the UE by a RRCRelease message.
  • the gNB-DU may send the information about triggering multicast reception in RRC_INACTIVE by an interface management F1 signaling (e.g., adding a new IE in RESOURCE STATUS RESPONSE) .
  • an interface management F1 signaling e.g., adding a new IE in RESOURCE STATUS RESPONSE
  • a new bit in Report Characteristics IE which is in RESOURCE STATUS REQUEST from gNB-CU is added. If the new bit is set to 1, gNB-DU can send the information about triggering multicast reception in RRC_INACTIVE by an interface management F1 signaling.
  • a UE list where the UEs in this list are released to RRC_INACTIVE state to receive multicast, can be carried in an interface management F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the resource usage of each UE can be included in the UE list.
  • a cell list where the cells in this list are triggered to multicast reception in RRC_INACTIVE, can be carried in an interface management F1 signaling from the gNB-DU to the gNB-CU-CP.
  • a session list where the sessions in this list are triggered to multicast reception in RRC_INACTIVE, can be carried in an interface management F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the gNB-CU may consider whether to release UE to RRC_INACTIVE state to receive multicast.
  • the gNB-CU may consider whether to release UE to RRC_INACTIVE state to receive multicast.
  • Option 1 Accept DU’s suggestion, release UE to RRC_INACTIVE state to receive multicast.
  • Option 2 Reject DU’s suggestion, keep UE in RRC_CONNECTED state to receive multicast.
  • an indication information indicating which multicast sessions are received in RRC_INACTIVE state in which cells, can be delivered to the DU.
  • the gNB-CU may always release the UEs which are in the list to RRC_INACTIVE state to receive multicast.
  • gNB-CU trigger multicast reception in RRC_INACTIVE
  • the gNB-CU may send the information about triggering multicast reception in RRC_INACTIVE state, in/by a UE-associated F1 signaling.
  • the example approach (es) can include the following.
  • ⁇ Define a new UE-associated F1 signaling (gNB-CU initiated) .
  • an indication information indicating that the UE is released to RRC_INACTIVE state to receive multicast, can be carried in a UE-associated F1 signaling from the gNB-CU to the gNB-DU.
  • the MRB configuration which is used for multicast reception in RRC_INACTIVE, can be carried in a UE-associated F1 signaling from the gNB-CU to the gNB-DU.
  • the cell ID can be included in the MRB configuration information.
  • the identifier (ID) of the cell may indicate which cell the configuration applies to.
  • the identifier (ID) of the cell may indicate which cell is configured for the multicast reception in RRC_INACTIVE state.
  • a response for MRB configuration establishment can be sent back to the gNB-CU.
  • a response for MRB configuration establishment can be sent back to the gNB-CU.
  • the gNB-DU may send it to the gNB-CU.
  • the PTM configuration which is used to receive multicast in the RRC_INACTIVE state, can be carried in a UE-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the configuration may include at least a lower layer PTM configuration. The configuration can be per session.
  • an indication information indicating that the PTM configuration used in RRC_CONNECTED can continue to be used in RRC_INACTIVE state, can be carried in a UE-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the indication can be per session.
  • an indication information indicating that the PTM configuration used in RRC_INACTIVE can be obtained from MCCH, can be carried in a UE-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the gNB-CU may consider whether to release UE to RRC_INACTIVE state to receive multicast.
  • Option 1 Accept DU’s suggestion, release UE to RRC_INACTIVE state to receive multicast.
  • Option 2 Reject DU’s suggestion, keep UE in RRC_CONNECTED state to receive multicast.
  • the gNB-CU may always release UE to RRC_INACTIVE state to receive multicast.
  • the gNB-CU may deliver the related information about PTM configuration used in RRC_INACTIVE in a RRCRelease message, where there can be various (e.g., three) options as follows.
  • the CU may deliver the PTM configuration to the UE by a RRCRelease message.
  • the CU can deliver the corresponding indication information to the UE by RRCRelease message.
  • the CU can deliver the corresponding indication information to the UE by RRCRelease message.
  • the gNB-CU may send the information about triggering multicast reception in RRC_INACTIVE by session-associated F1 signaling.
  • the example approaches can including one or more of the following.
  • ⁇ Define a new multicast session-associated F1 signaling (gNB-CU initiated) .
  • indication information indicating that the session is to be configured for the multicast reception in RRC_INACTIVE state can be carried in a session-associated F1 signaling from the gNB-CU to the gNB-DU.
  • a UE list where UEs in this list are released to RRC_INACTIVE state to receive multicast, can be carried in a session-associated F1 signaling from the gNB-CU to the gNB-DU.
  • a cell list where cells in this list are triggered to multicast reception in RRC_INACTIVE, can be carried in a session-associated F1 signaling from the gNB-CU to the gNB-DU.
  • the MRB configuration list where MRB configurations in this list can be used for multicast reception in RRC_INACTIVE state
  • the cell ID indicating which cell the MRB configuration applies to, can be included in the MRB configuration information.
  • a response for accepting or rejecting some/all/none of the UEs of the UE list can be sent back to the gNB-CU.
  • a response for MRB configuration establishment (e.g., accepting or rejecting some/all/none of the MRB configurations of the MRB configurationlist) , can be sent back to the gNB-CU.
  • MRB configuration establishment e.g., accepting or rejecting some/all/none of the MRB configurations of the MRB configurationlist.
  • gNB-DU may send it to gNB-CU.
  • the PTM configuration list which is used to receive multicast in the RRC_INACTIVE state, can be carried in a session-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • the configuration may include at least a lower layer PTM configuration.
  • a cell ID indicating which cell the new configuration applies to, can be included in the PTM configuration.
  • an indication information list indicating that the PTM configuration used in RRC_CONNECTED can continue to be used in RRC_INACTIVE state, can be carried in a session-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • a cell ID indicating which cell the new configuration applies to, can be included in the PTM configuration.
  • an indication information indicating the PTM configuration used in RRC_INACTIVE can be obtained from MCCH, may be carried in a session-associated F1 signaling from the gNB-DU to the gNB-CU-CP.
  • a cell ID indicating which cell the new configuration applies to, can be included in the PTM configuration.
  • the gNB-CU may consider whether to release UE to RRC_INACTIVE state to receive multicast.
  • gNB-CU may consider whether to release UE to RRC_INACTIVE state to receive multicast.
  • Option 1 Accept DU’s suggestion, release UE to RRC_INACTIVE state to receive multicast.
  • Option 2 Reject DU’s suggestion, keep UE in RRC_CONNECTED state to receive multicast.
  • the gNB-CU may (always) release UE to RRC_INACTIVE state to receive multicast.
  • the gNB-CU may deliver the related information about PTM configuration used in RRC_INACTIVE in a RRCRelease message, where there can be various options, for instance three options as follows.
  • the CU can deliver the PTM configuration to the UE by RRCRelease message.
  • the CU can deliver the corresponding indication information to the UE by RRCRelease message.
  • the CU can deliver the corresponding indication information to the UE by a RRCRelease message.
  • the CU-control plane may notify CU-user plane (UP) of the session state/configuration state.
  • the CU-CP may send a session state/configuration state, by per session E1 signaling, to the CU-UP.
  • the gNB-CU-CP may establish the multicast bearer context at the gNB-CU-UP. Whether the gNB-CU-UP can be provided with the session state is discussed herein.
  • the gNB-CU-UP can distinguish/identify configurations which are/is pre-configuration (s) for the non-ongoing multicast session (s) , there can be a better control of multicast session resources:
  • the gNB-CU-UP may not release these pre-configurations when there is no data transmission for a long time.
  • an indication per session can be added in E1 signaling (e.g., 1 bit in MC BEARER CONTEXT SETUP REQUEST/MC BEARER CONTEXT MODIFICATION REQUEST) from the gNB-CU-CP.
  • This indication can be used to notify gNB-CU-UP that the multicast session is non-ongoing and a certain configuration is a pre-configuration.
  • the context/content of the indication can be session state (ongoing/non-ongoing/active/inactive) or the configuration state (pre-configuration or not) .
  • FIG. 3 illustrates a flow diagram of a method 300 for supporting multicast reception in RRC_INACTIVE state.
  • the method 300 may be implemented using any one or more of the components and devices detailed herein in conjunction with FIGs. 1–2.
  • the method 300 may be performed by a centralized unit (CU) or a distributed unit (DU) of a wireless communication node (e.g., a BS) , in some embodiments. Additional, fewer, or different operations may be performed in the method 300 depending on the embodiment. At least one aspect of the operations is directed to a system, method, apparatus, or a computer-readable medium.
  • a centralized unit (CU) of a wireless communication node may receive a first signaling from a distributed unit (DU) of the wireless communication node.
  • the first signaling may include information about multicast reception in RRC_INACTIVE state of at least a first wireless communication device (e.g., a user equipment (UE) ) .
  • the first signaling can be for the first wireless communication device (e.g., per UE or specific to the UE) .
  • the first signaling may comprise at least one of: indication information indicating that the first wireless communication device is to be configured for the multicast reception in RRC_INACTIVE state; a cause value, indicating that a reason for releasing the first wireless communication device to RRC_INACTIVE state is that the first wireless communication device is configured to receive multicast in RRC_INACTIVE state; an identifier (ID) of a cell, which indicates which cell is to be triggered for multicast reception in RRC_INACTIVE state, is contained in the indication information; point-to-multipoint (PTM) configuration information, which can be used for the multicast reception in RRC_INACTIVE state; or indication information.
  • the PTM configuration information may include PTM configuration of a lower layer (or any one or more specific layers) .
  • the PTM configuration information can be for a session (e.g., per session or specific to a session) .
  • the indication information may indicate that PTM configuration used in RRC_CONNECTED state is to continue to be used in RRC_INACTIVE state.
  • the indication information may indicate that the PTM configuration to be used in RRC_INACTIVE state is to be obtained/received via a multicast-broadcast service control channel (MCCH) .
  • MCCH multicast-broadcast service control channel
  • the indication information can be for (e.g., specifically for) the session.
  • the CU may determine, according to the second signaling, to release the first wireless communication device to RRC_INACTIVE state.
  • the CU may send, to the first wireless communication device, a RRCRelease message including the indication information indicating the PTM configuration to be used in RRC_INACTIVE state.
  • a control plane of the CU e.g., CU-CP
  • the CU may send a confirm message for the multicast reception in RRC_INACTIVE state to the DU.
  • the confirm message may include first indication information indicating that corresponding multicast sessions are to be received in RRC_INACTIVE state in a certain cell.
  • the confirm message can be for the first wireless communication device.
  • the first signaling can be for a session.
  • the information may comprise (an indication of) at least one of: indication information indicating that the session is to be configured for the multicast reception in RRC_INACTIVE state; a list of wireless communication devices that are to be released to RRC_INACTIVE state for multicast reception; a list of cells that are to be triggered for multicast reception in RRC_INACTIVE state; a list of PTM configurations that are to be used in RRC_INACTIVE state; a list of indication information indicating that the PTM configurations to be used in RRC_CONNECTED state are to continue to be used in RRC_INACTIVE state; or a list of indication information indicating the PTM configurations to be used in RRC_INACTIVE state are to be obtained via a multicast-broadcast service control channel (MCCH) .
  • MCCH multicast-broadcast service control channel
  • the CU may determine, according to the first signaling, to release the first wireless communication device to RRC_INACTIVE state.
  • the CU may send, to the first wireless communication device, a RRCRelease message including the indication information indicating the PTM configuration to be used in RRC_INACTIVE state.
  • a control plane of the CU may send, to a user plane of the CU, the information about multicast reception in RRC_INACTIVE state, in an E1 signaling for the session.
  • the CU may send a confirm message for the multicast reception in RRC_INACTIVE state to the DU.
  • the confirm message may include first indication information indicating that corresponding multicast session is to be received in RRC_INACTIVE state in some certain cells. The confirm message can be for a session.
  • the first signaling can be regarding interface management.
  • the information may comprise (an indication of) at least one of: a list of wireless communication devices that are to be released to RRC_INACTIVE state for multicast reception; an indication of resource usage for the first wireless communication device, the indication included in the list of wireless communication devices; a list of cells that are to be triggered for multicast reception in RRC_INACTIVE state; or a list of multicast sessions that are to be received in RRC_INACTIVE state.
  • the CU may determine, according to the first signaling, to release the first wireless communication device to RRC_INACTIVE state.
  • the CU may send, to the first wireless communication device, a RRCRelease message including the indication information indicating the PTM configuration to be used in RRC_INACTIVE state.
  • a control plane of the CU may send, to a user plane of the CU, the information about multicast reception in RRC_INACTIVE state, in an E1 signaling for a session.
  • the CU may incorporate/insert/include/carry/send the PTM configuration in the RRCRelease message. If the second signaling includes the indication information indicating that the PTM configuration used in RRC_CONNECTED state is to continue to be used in RRC_INACTIVE state, the CU may incorporate/insert/include/carry/send the indication information indicating that the PTM configuration used in RRC_CONNECTED state is to continue to be used in RRC_INACTIVE state in the RRCRelease message.
  • the CU may incorporate/insert/include/carry the indication information indicating that the PTM configuration used in RRC_INACTIVE state is to be obtained via the MCCH in the RRCRelease message.
  • the CU may incorporate/insert/include/carry/send, in the RRCRelease message, a first indication for the session, to indicate whether the wireless communication device is to (or can) monitor for a group radio network temporary identifier (G-RNTI) immediately after transitioning to RRC_INACTIVE state.
  • G-RNTI group radio network temporary identifier
  • the CU may incorporate/insert/include/carry/send, in the RRCRelease message, an identifier (ID) of a cell in the PTM configuration information.
  • the first indication may indicate whether a session state is inactive or active. If the session state is active, the wireless communication device is to (or can) monitor for the G-RNTI for multicast reception after transitioning to RRC_INACTIVE state. If the session state is inactive, the first wireless communication device is not to (or cannot) monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the first indication may indicate the PTM configuration, the PTM configuration comprising at least one of: a pre-configuration which is used upon session activation, or an ongoing-configuration which is used to receive a corresponding active session immediately after transitioning to RRC_INACTIVE state. If the PTM configuration comprises the pre-configuration, the first wireless communication device is to (or can) store the pre-configuration and not use the pre-configuration to monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state. If the PTM configuration comprises the ongoing-configuration, the first wireless communication device is to (or can) use the ongoing-configuration to monitor for the G-RNTI immediately after transitioning to RRC_INACTIVE state.
  • the first indication may indicate a behavior of the first wireless communication device in RRC_INACTIVE state.
  • the behavior may include that the first wireless communication device is to (or can) monitor for the G-RNTI (e.g., immediately) after transitioning to the RRC_INACTIVE state.
  • the behavior may include that the first wireless communication device is not to (or may not) monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the CU may send, to the first wireless communication device, a RRCRelease message comprising a first indication for a session, the first indication to indicate whether the wireless communication device is to (or can) monitor for a group radio network temporary identifier (G-RNTI) .
  • the first indication may indicate whether a session state is inactive or active. If the session state is active, the wireless communication device is to (or can) monitor for the G-RNTI for multicast reception after transitioning to RRC_INACTIVE state. If the session state is inactive, the first wireless communication device is not to (or may not) monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the first indication may indicate a point-to-multipoint (PTM) configuration, the PTM configuration comprising at least one of: a pre-configuration which is used upon session activation, or an ongoing-configuration in which starts monitoring the session immediately after transitioning to RRC_INACTIVE state.
  • PTM configuration comprises the pre-configuration
  • the first wireless communication device is to (or can) store the pre-configuration and/or not use the pre-configuration to monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the PTM configuration comprises the ongoing-configuration
  • the first wireless communication device is to (or can) use the ongoing-configuration to monitor for the G-RNTI immediately after transitioning to RRC_INACTIVE state.
  • the first indication may indicate a behavior of the first wireless communication device in RRC_INACTIVE state.
  • the behavior may include that the first wireless communication device is to (or can) monitor for the G-RNTI immediately after transitioning to the RRC_INACTIVE state.
  • the behavior may include that the first wireless communication device is not to (or may not) monitor for the G-RNTI until a corresponding activation indication is received from the wireless communication node after transitioning to RRC_INACTIVE state.
  • the CU may incorporate/insert/include/carry/send, in the RRCRelease message, an identifier (ID) of a cell in the PTM configuration information.
  • ID an identifier
  • a control plane of the CU may send, to a user plane of the CU, at least one of session state or configuration state, in an E1 signaling for a session.
  • a distributed unit (DU) of a wireless communication node may send a first signaling to a centralized unit (CU) of the wireless communication node.
  • the first signaling may include information about multicast reception in RRC_INACTIVE state of at least a first wireless communication device.
  • any reference to an element herein using a designation such as “first, “ “second, “ and so forth does not generally limit the quantity or order of those elements. Rather, these designations can be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements can be employed, or that the first element must precede the second element in some manner.
  • any of the various illustrative logical blocks, modules, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two) , firmware, various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as "software” or a "software module) , or any combination of these techniques.
  • firmware e.g., a digital implementation, an analog implementation, or a combination of the two
  • firmware various forms of program or design code incorporating instructions
  • software or a “software module”
  • IC integrated circuit
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • the logical blocks, modules, and circuits can further include antennas and/or transceivers to communicate with various components within the network or within the device.
  • a general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine.
  • a processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein.
  • Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program or code from one place to another.
  • a storage media can be any available media that can be accessed by a computer.
  • such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.
  • module refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various modules are described as discrete modules; however, as would be apparent to one of ordinary skill in the art, two or more modules may be combined to form a single module that performs the associated functions according embodiments of the present solution.
  • memory or other storage may be employed in embodiments of the present solution.
  • memory or other storage may be employed in embodiments of the present solution.
  • any suitable distribution of functionality between different functional units, processing logic elements or domains may be used without detracting from the present solution.
  • functionality illustrated to be performed by separate processing logic elements, or controllers may be performed by the same processing logic element, or controller.
  • references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne des systèmes et des procédés pour prendre en charge une réception de multidiffusion dans un état RRC_INACTIVE. Une unité centralisée (CU) d'un nœud de communication sans fil peut recevoir une première signalisation provenant d'une unité distribuée (DU) du nœud de communication sans fil. La première signalisation peut comprendre des informations concernant une réception de multidiffusion dans un état RRC_INACTIVE d'au moins un premier dispositif de communication sans fil.
PCT/CN2023/112257 2023-08-10 2023-08-10 Systèmes et procédés pour prendre en charge une réception de multidiffusion dans un état rrc_inactive WO2024113951A1 (fr)

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PCT/CN2023/112257 WO2024113951A1 (fr) 2023-08-10 2023-08-10 Systèmes et procédés pour prendre en charge une réception de multidiffusion dans un état rrc_inactive

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Citations (3)

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US20230007444A1 (en) * 2020-01-23 2023-01-05 Lg Electronics Inc. Switching between unicast and multicast by considering degraded user experience in a wireless communication system
WO2023013605A1 (fr) * 2021-08-02 2023-02-09 京セラ株式会社 Procédé de communication, dispositif de réseau et dispositif utilisateur
CN116326004A (zh) * 2020-10-10 2023-06-23 联想(北京)有限公司 用于控制信号的发射的方法及设备

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US20230007444A1 (en) * 2020-01-23 2023-01-05 Lg Electronics Inc. Switching between unicast and multicast by considering degraded user experience in a wireless communication system
CN116326004A (zh) * 2020-10-10 2023-06-23 联想(北京)有限公司 用于控制信号的发射的方法及设备
WO2023013605A1 (fr) * 2021-08-02 2023-02-09 京セラ株式会社 Procédé de communication, dispositif de réseau et dispositif utilisateur

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ZTE: "Multicast reception in RRC_INACTIVE", 3GPP DRAFT; R3-225854, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, vol. RAN WG3, no. Online; 20221010 - 20221018, 28 September 2022 (2022-09-28), Mobile Competence Centre ; 650, route des Lucioles ; F-06921 Sophia-Antipolis Cedex ; France, XP052265994 *

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