Method for handling small data transmission and multicast page and apparatus therefor

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. According to the disclosure, a method performed by a user equipment (UE) in a wireless communication system, the method comprising: receiving, from a base station, a radio resource control (RRC) release message including first configuration for a RRC inactive state, the first configuration including second configuration associated with multicast reception in the RRC inactive state; and performing the multicast reception in the RRC inactive state based on the second configuration.

Description

METHOD FOR HANDLING SMALL DATA TRANSMISSION AND MULTICAST PAGE AND APPARATUS THEREFOR

[0001] The proposed embodiments relates to telecommunication network system. More particularly present disclosure relates to handling small data transmission and multicast paging.

[0002] New Radio (NR) Multicast and Broadcast Services (MBS) services can refer to multicast services where intended common contents are targeted to a group of User Equipment (UE), which have joined the multicast group in the multicast coverage area and to broadcast services where intended contents may be targeted to all the UEs in the broadcast coverage area. This coverage area can be one radio cell or larger.

[0003] Specifically, multicast services refer to services being transmitted and availed by a set of UEs registered to a group for example, MCPTT (Mission Critical Push-To-Talk) service. Broadcast services refer to services being transmitted and available to all the UEs in a specific coverage area where the broadcast is performed and typically, the UE need not be registered. Therefore, effectively, both multicast and broadcast services are PTM (Point-To-MultiPoint) services, as there is one transmitter and multiple recipients. It is also possible to provide multicast and / or broadcast services in a PTP (Point-to-Point) manner, wherein there are multiple PTP connections to share the same MBS services with multiple recipients. Apart from multicast and broadcast services, there are another category of services termed as unicast services which is meant for one recipient only for this is one to one dedicated connection between the transmitter and the receiver.

[0004] It is possible to have PTM bearers, PTP bearers or a combination of PTM and PTP bearers (or reception paths) to carry the same MBS service. A combination of PTM and PTP bearers (or reception paths) may provide a lot of features with respect to increased reliability of reception of the MBS service packets, and efficient switching between these two modes of reception (when needed); for example, because of mobility, network loading conditions or based on the user request density for the reception of the MBS service and accordingly, the network may decide the delivery modes and / or switching across. Embodiments herein may refer to the bearer configuration, which has possibly both legs of PTM and PTP termed as MBS split bearer.

[0005] In the legacy system (i.e., 3GPP Release 17 MBS), the UEs could receive multicast service only in the RRC_CONNECTED state. For the purpose of informing the UEs in the RRC IDLE state or RRC INACTIVE state about multicast session "activation", a group notification or group paging mechanism is utilized. Based on reception of this paging, the UE transits to RRC CONNECTED state and starts receiving the multicast session. However, there may also be UEs which can receive multicast session(s) in the RRC INACTIVE state (e.g., 3GPP Release 18 MBS may consider such a scenario).

[0006] SDT is a procedure that allows data and / or signaling transmission while the UE is remaining in the RRC INACTIVE state (i.e., without transitioning to the RRC CONNECTED state). The SDT is enabled on a radio bearer basis and is initiated by the UE only if less than a configured amount of Uplink (UL) data awaits transmission across all radio bearers for which the SDT is enabled, the downlink (DL) Reference Signal Received Power (RSRP) is above a configured threshold, and a valid SDT resource is available. Logical channel restrictions configured by the network while in the RRC CONNECTED state and / or in RRC Release message for radio bearers enabled for the SDT, if any, are applied by the UE during the SDT procedure.

[0007] A potential issue relates to the UEs that are capable of receiving the MBS multicast service in the RRC INACTIVE state. In conventional method, service could be received only in the RRC CONNECTED state. When such UEs avail multicast services in the RRC INACTIVE state, the SDT procedure may be configured and initiated. At the UE the reception of multicast session activation notification while SDT procedure is ongoing is not clear. In conventional method, paging monitoring is not performed while the SDT procedure is on-going as the UE may transitioned if it were actually paged as part of the SDT procedure. However, when the MBS multicast session is to be provided in the RRC INACTIVE state (e.g. network is congested), there is an ambiguity as to how this is achieved.

[0008] Thus, it is desired to address the above-mentioned disadvantages or other shortcomings or at least provide a useful alternative.

[0009] 5th generation (5G) or new radio (NR) mobile communications is recently gathering increased momentum with all the worldwide technical activities on the various candidate technologies from industry and academia. The candidate enablers for the 5G / NR mobile communications include massive antenna technologies, from legacy cellular frequency bands up to high frequencies, to provide beamforming gain and support increased capacity, new waveform (e.g., a new radio access technology (RAT)) to flexibly accommodate various services / applications with different requirements, new multiple access schemes to support massive connections, and so on.

[0010] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in "Sub 6GHz" bands such as 3.5GHz, but also in "Above 6GHz" bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0011] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0012] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0013] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0014] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0015] The principal object of the embodiments herein is to handle small data transmission and multicast paging.

[0016] Another object of the invention is to handle SDT and multicast paging along with NR MBS multicast reception, where the UE can receive the multicast service in RRC INACTIVE state.

[0017] Another object of the invention is to notify the UE about activation of multicast session while an SDT procedure is ongoing in RRC INACTIVE state.

[0018] Another objective of the invention is to achieve at the UE concurrent multicast session activation notification and SDT operation in RRC INACTIVE.

[0019] A method performed by a user equipment (UE) in a wireless communication system, the method comprising: receiving, from a base station, a radio resource control (RRC) release message including first configuration for a RRC inactive state, the first configuration including second configuration associated with multicast reception in the RRC inactive state; and performing the multicast reception in the RRC inactive state based on the second configuration.

[0020] A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a user equipment (UE), a radio resource control (RRC) release message including first configuration for a RRC inactive state, the first configuration including second configuration associated with multicast reception in the RRC inactive state; and performing the multicast transmission to the UE in the RRC inactive state based on the second configuration.

[0021] A user equipment (UE) in a wireless communication system, the UE comprising: a transceiver; and a controller coupled with the transceiver and configured to: receive, from a base station, a radio resource control (RRC) release message including first configuration for a RRC inactive state, the first configuration including second configuration associated with multicast reception in the RRC inactive state, and perform the multicast reception in the RRC inactive state based on the second configuration.

[0022] A base station in a wireless communication system, the base station comprising: a transceiver; and a controller coupled with the transceiver and configured to: transmit, to a user equipment (UE), a radio resource control (RRC) release message including first configuration for a RRC inactive state, the first configuration including second configuration associated with multicast reception in the RRC inactive state, and perform the multicast transmission to the UE in the RRC inactive state based on the second configuration.

[0023] These and other features, aspects, and advantages of the present embodiments are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:

[0024] FIG. 1 is a block diagram that illustrates a User Equipment for handling SDT and multicast paging, according to the embodiment as disclosed herein;

[0025] FIG. 2 is a block diagram that illustrates a network apparatus for handling SDT and multicast paging, according to the embodiment as disclosed herein;

[0026] FIG. 3A and 3B are a sequence diagram that illustrates an interaction between UE and network apparatus for handling SDT and multicast paging, according to the embodiment as disclosed herein;

[0027] FIG. 4A and 4B are a flow diagram that illustrates a method for handling SDT and multicast paging, according to embodiments as disclosed herein;

[0028] FIG. 5 is a flow diagram that illustrates a method for handling SDT and multicast paging, according to embodiments as disclosed herein;

[0029] FIG. 6 is a flow diagram that illustrates a method for handling SDT and multicast paging, according to embodiments as disclosed herein;

[0030] FIG. 7 is a flow diagram that illustrates a method for handling SDT and multicast paging by UE, according to embodiments as disclosed herein;

[0031] FIG. 8 is a flow diagram that illustrates a method for handling SDT and multicast paging by network apparatus, according to embodiments as disclosed. herein;

[0032] It may be noted that to the extent possible, like reference numerals have been used to represent like elements in the drawing. Further, those of ordinary skill in the art will appreciate that elements in the drawing are illustrated for simplicity and may not have been necessarily drawn to scale. For example, the dimension of some of the elements in the drawing may be exaggerated relative to other elements to help to improve the understanding of aspects of the invention. Furthermore, the elements may have been represented in the drawing by conventional symbols, and the drawings may show only those specific details that are pertinent to the understanding the embodiments of the invention so as not to obscure the drawing with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

[0033] In one aspect, the objectives are achieved by providing a method for handling Small Data Transmission (SDT) and multicast paging. The method includes receiving, by a User Equipment (UE), while the UE is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate reception of at least one multicast session in RRC INACTIVE state. The RRC release with suspend configuration message comprises at least one of a multicast Point-To-Multipoint (PTM) configuration. Further, the method includes transiting, by the UE, from the RRC CONNECTED state to RRC INACTIVE state. Further, the method includes receiving, by the UE, the at least one multicast session, when the multicast session is activated. Further, the method includes determining, by the UE, whether a SDT procedure is initiated or ongoing. Further, the method includes continue receiving, by the UE, the at least one ongoing multicast session, when SDT procedure is initiated or ongoing. Further, the method includes skips monitoring, by the UE, a paging channel for group paging message that notifies regarding activation of the at least one new multicast session, when the SDT procedure is initiated or ongoing. Further, the method includes receiving, by the UE, while the UE in RRC INACTIVE state, a second RRC release with suspend configuration message that indicates activation of the at least one new multicast session while the SDT procedure is initiated or ongoing and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state. Further, the method includes, start receiving, by the UE, at least one new multicast session in the RRC INACTIVE state.

[0034] In an embodiment, the method includes applying, by the UE, PTM configuration received in the second RRC release with suspend configuration message. Further, the method includes monitoring, by the UE, multicast MBS Control Channel (MCCH) Radio Network Temporary Identifier (RNTI) and acquiring multicast MCCH. Further, the method includes starts receiving, by the UE, at least one new multicast session in the RRC INACTIVE state and while the SDT procedure is initiated or on-going; and skip monitoring, by the UE, a paging channel for group paging message that notifies regarding activation of the at least one new multicast session activation, when the SDT procedure is initiated or ongoing.

[0035] In an embodiment, the method includes receiving, by the UE, a RRC resume message, while the SDT procedure is initiated or ongoing and the UE is not capable of receiving the at least one multicast session in RRC INACTIVE state. Further, the method includes transiting, by the UE, from the RRC INACTIVE state to a RRC CONNECTED state. Further, the method includes receiving, by the UE, the at least one multicast session in the RRC CONNECTED state.

[0036] In an embodiment, the method includes receiving, by the UE, the second RRC release with suspend configuration message while the SDT procedure is completed and the UE is capable of receiving the at least one multicast session in RRC INACTIVE state. Further, the method includes resume monitoring, by the UE, paging channel for group paging message in the RRC INACTIVE state that notifies regarding activation of the at least one multicast session activation.

[0037] In an embodiment, the second RRC release with suspend configuration message comprises at least one multicast PTM configuration for the activated multicast session, an activation indication, or a TMGI or a multicast session identity of the activated multicast session.

[0038] In an embodiment, the at least one new multicast session is the at least one multicast session that is not activated before receiving the second RRC release with suspend configuration message.

[0039] Accordingly, the embodiment herein is to provide a method for handling Small Data Transmission (SDT) and multicast paging. The method includes transmitting, by a network apparatus, while UE is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate the reception of at least one multicast session in RRC INACTIVE state. The first RRC release with suspend configuration message comprises at least one of a multicast PTM configuration. Further, the method includes transiting, by the network apparatus, the UE from RRC CONNECTED state to a RRC INACTIVE state. Further, the method includes transmitting, by the network apparatus, the at least one multicast session, when the multicast session is determined to be activated. Further, the method includes transmitting, by the network apparatus, the at least one ongoing multicast session and a group paging message that notifies regarding activation of the at least one new multicast session. Further, the method includes determining, by the network apparatus, whether the SDT procedure is at least one initiated, ongoing or completed at the UE and UE is capable of receiving the at least one multicast session in RRC INACTIVE state and UE is in RRC INACTIVE state. Further, the method includes transmitting, by the network apparatus, a second RRC release with suspend configuration message to the UE to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is at least one of initiated or ongoing for the UE and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0040] In an embodiment, the method includes. transmitting, by the network apparatus, a RRC resume message to provide at least one new multicast session in RRC CONNECTED state and the UE is not capable of receiving the at least one multicast session in the RRC INACTIVE state. Further, the method includes transmitting, by the network apparatus, a second RRC release with suspend configuration message to the UE to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is completed and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0041] In an embodiment, the second RRC release with suspend configuration message comprises at least one multicast PTM configuration for the activated multicast session, an activation indication, or a TMGI or a multicast session identity of the activated multicast session.

[0042] Accordingly, the embodiment herein is to provide a UE for handling Small Data Transmission (SDT) and multicast paging. The UE comprises a processor and SDT and multicast session handler that is coupled to the processor. The SDT and multicast session handler receives while the UE is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate reception of at least one multicast session in RRC INACTIVE state. The RRC release with suspend configuration message comprises at least one of a multicast PTM configuration. Further, the SDT and multicast session handler transits the UE from the RRC CONNECTED state to RRC INACTIVE state. Further, the SDT and multicast session handler receives the at least one multicast session, when the multicast session is activated. Further, the SDT and multicast session handler determines whether a SDT procedure is initiated or ongoing. Further, the SDT and multicast session handler continues to receive the at least one ongoing multicast session, when SDT procedure is initiated or ongoing. Further, the SDT and multicast session handler skip to monitor a paging channel for group paging message that notifies regarding activation of the at least one new multicast session, when the SDT procedure is initiated or ongoing. Further, the SDT and multicast session handler receive while the UE in RRC INACTIVE state, a second RRC release with suspend configuration message that indicates activation of the at least one new multicast session while the SDT procedure is initiated or ongoing and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state. Further, the SDT and multicast session handler start to receive at least one new multicast session in the RRC INACTIVE state.

[0043] Accordingly, the embodiment herein is to provide a network apparatus for handling Small Data Transmission (SDT) and multicast paging. The network apparatus comprises a processor and a SDT and multicast session handler that is coupled to the processor. The SDT and multicast session handler transmits while UE is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate the reception of at least one multicast session in RRC INACTIVE state. The first RRC release with suspend configuration message comprises at least one of a multicast PTM configuration. Further, the SDT and multicast session handler transits the UE form RRC CONNECTED state to a RRC INACTIVE state. Further, the SDT and multicast session handler transmits the at least one multicast session, when the multicast session is determined to be activated. Further, the SDT and multicast session handler transmits the at least one ongoing multicast session and a group paging message that notifies regarding activation of the at least one new multicast session. Further, the SDT and multicast session handler determines whether the SDT procedure is at least one initiated, ongoing or completed at the UE and UE is capable of receiving the at least one multicast session in RRC INACTIVE state and UE is in RRC INACTIVE state. Further, the SDT and multicast session handler transmit a second RRC release with suspend configuration message to the UE to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is at least one of initiated or ongoing for the UE and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0044] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications be made within the scope of the embodiments herein.

[0045] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term "or" as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples are not be construed as limiting the scope of the embodiments herein.

[0046] As is traditional in the field, embodiments are described and illustrated in terms of blocks that carry out a described function or functions.　These blocks, which referred to herein as managers, units, modules, hardware components or the like, are physically implemented by analog and / or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and optionally be driven by firmware and software. The circuits, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like.　The circuits constituting a block be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block. Each block of the embodiments be physically separated into two or more interacting and discrete blocks without departing from the scope of the proposed method.　Likewise, the blocks of the embodiments be physically combined into more complex blocks without departing from the scope of the proposed method.

[0047] The accompanying drawings are used to help easily understand various technical features and it is understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the proposed method is construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. used herein to describe various elements, these elements are not be limited by these terms. These terms are generally used to distinguish one element from another.

[0048] Accordingly, the embodiments disclose a method for handling Small Data Transmission (SDT) and multicast paging. The method includes receiving, by the User Equipment (UE), while the UE is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate reception of at least one multicast session in RRC INACTIVE state. The RRC release with suspend configuration message comprises at least one of a multicast Point-To-Multipoint (PTM) configuration. Further, the method includes transiting, by the UE, from the RRC CONNECTED state to RRC INACTIVE state. Further, the method includes receiving, by the UE, the at least one multicast session, when the multicast session is activated. Further, the method includes determining, by the UE, whether a SDT procedure is initiated or ongoing. Further, the method includes continue receiving, by the UE, the at least one ongoing multicast session, when SDT procedure is initiated or ongoing. Further, the method includes skip monitoring, by the UE, a paging channel for group paging message that notifies regarding activation of the at least one new multicast session, when the SDT procedure is initiated or ongoing. Further, the method includes receiving, by the UE, while the UE in RRC INACTIVE state, a second RRC release with suspend configuration message that indicates activation of the at least one new multicast session while the SDT procedure is initiated or ongoing and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state. Further, the method includes starts receiving, by the UE, at least one new multicast session in the RRC INACTIVE state.

[0049] Accordingly, the embodiments disclose a method for handling Small Data Transmission (SDT) and multicast paging. The method includes transmitting, by a network apparatus, while UE is in Radio Resource Control (RRC) CONNECTED state, the first RRC release with suspend configuration message to indicate the reception of at least one multicast session in RRC INACTIVE state. The first RRC release with suspend configuration message comprises at least one of a multicast PTM configuration. Further, the method includes transiting, by the network apparatus, the UE from RRC CONNECTED state to a RRC INACTIVE state. Further, the method includes transmitting, by the network apparatus, the at least one multicast session, when the multicast session is determined to be activated. Further, the method includes transmitting, by the network apparatus, the at least one ongoing multicast session and a group paging message that notifies regarding activation of the at least one new multicast session. Further, the method includes determining, by the network apparatus, whether the SDT procedure is at least one initiated, ongoing or completed at the UE and UE is capable of receiving the at least one multicast session in RRC INACTIVE state and UE is in RRC INACTIVE state. Further, the method includes transmitting, by the network apparatus, a second RRC release with suspend configuration message to the UE to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is at least one of initiated or ongoing for the UE and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0050] Accordingly, the embodiments disclose a UE for handling Small Data Transmission (SDT) and multicast paging. The UE comprises a processor and a SDT and multicast session handler coupled to the processor. The SDT and multicast session handler receives while the UE is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate reception of at least one multicast session in RRC INACTIVE state. The RRC release with suspend configuration message comprises at least one of a multicast PTM configuration. Further, the SDT and multicast session handler transits from the RRC CONNECTED state to RRC INACTIVE state. Further, the SDT and multicast session handler receives the at least one multicast session, when the multicast session is activated. Further, the SDT and multicast session handler determines whether a SDT procedure is initiated or ongoing. Further, the SDT and multicast session handler continues to receive the at least one ongoing multicast session, when SDT procedure is initiated or ongoing. Further, the SDT and multicast session handler skip to monitor a paging channel for group paging message that notifies regarding activation of the at least one new multicast session, when the SDT procedure is initiated or ongoing. Further, the SDT and multicast session handler receives while the UE in RRC INACTIVE state, a second RRC release with suspend configuration message that indicates activation of the at least one new multicast session while the SDT procedure is initiated or ongoing and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state. Further, the SDT and multicast session handler start to receive at least one new multicast session in the RRC INACTIVE state.

[0051] Accordingly, the embodiments discloses a network apparatus for handling Small Data Transmission (SDT) and multicast paging. The network apparatus comprises a processor and a SDT and multicast session handler coupled to the processor. The SDT and multicast session handler transmit while UE is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate the reception of at least one multicast session in RRC INACTIVE state. The first RRC release with suspend configuration message comprises at least one of a multicast Point-To-Multipoint (PTM) configuration. Further, the SDT and multicast session handler transit the UE form RRC CONNECTED state to a RRC INACTIVE state. Further, the SDT and multicast session handler transmits the at least one multicast session, when the multicast session is determined to be activated. Further, the SDT and multicast session handler transmits the at least one ongoing multicast session and a group paging message that notifies regarding activation of the at least one new multicast session. Further, the SDT and multicast session handler determines whether the SDT procedure is at least one initiated, ongoing or completed at the UE and UE is capable of receiving the at least one multicast session in RRC INACTIVE state and UE is in RRC INACTIVE state. Further, the SDT and multicast session handler transmit a second RRC release with suspend configuration message to the UE to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is at least one of initiated or ongoing for the UE and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0052] The proposed solution provides a method for handling SDT and multicast paging. The proposed solution provides a method for notifying multicast session activation (i.e. group paging) when operating together with SDT in RRC INACTIVE. The proposed solution provides an efficient and effective approach for concurrent multicast session activation notification and SDT operation in RRC INACTIVE. Further, in the proposed solution the UE and network multicast data reception performance will gain significantly.

[0053] FIG. 1 is a block diagram that illustrates a User Equipment for handling SDT and multicast paging, according to the embodiment as disclosed herein.

[0054] The UE (101) includes a processor (103), a memory (107), an I / O interface (105) and a SDT and multicast session handler (109). The UE (101) communicates with a network apparatus for handling SDT and multicast paging. For example, the UE (101) can include, but not limited to a laptop, a palmtop, a desktop, a mobile phone, a smart phone, Personal Digital Assistant (PDA), a tablet, a wearable device, an Internet of Things (IoT) device, a virtual reality device, a television, a connected car, a foldable device, a flexible device, a display device and an immersive system. Further, the processor (103) of the UE (101) communicates with the memory (107), the I / O interface (105) and the SDT and multicast session handler (109). The processor (103) is configured to execute instructions stored in the memory (107) and to perform various processes. The processor (103) can include one or a plurality of processors, can be a general-purpose processor, such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and / or an Artificial intelligence (AI) dedicated processor such as a neural processing unit (NPU).

[0055] Further, the memory (107) of the UE (101) includes storage locations to be addressable through the processor (103). The memory (107) is not limited to a volatile memory and / or a non-volatile memory. Further, the memory (107) can include one or more computer-readable storage media. The memory (107) can include non-volatile storage elements. For example, non-volatile storage elements can include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. Also, the memory (107) of the UE (101) can store several information received from network apparatus. For example, the memory (107) can store several information such as a PTM configuration, TMGIs, multicast session activation indication and the like. Also, the UE (101) stores the data received in a RRC release message, group paging message that is received from the network apparatus.

[0056] The I / O interface (105) transmits the information between the memory (107) and external peripheral devices. The peripheral devices are the input-output devices associated with the network apparatus. The I / O interface (105) receives several information from the network apparatus. The several information received from the network apparatus can include but not limited to the list of PTM configuration, TMGIs, multicast session activation indication and the like.

[0057] The SDT and multicast session handler (109) communicates with the I / O interface (105) and memory (107) for handling SDT and multicast paging. The SDT and multicast session handler (109) while the UE (101) is in Radio Resource Control (RRC) CONNECTED state, the first RRC release with suspend configuration message to indicate reception of at least one multicast session in RRC INACTIVE state. The RRC release with suspend configuration message comprises at least one of a multicast Point-To-Multipoint (PTM) configuration. Further, the SDT and multicast session handler (109) transits from the UE (101) from the RRC CONNECTED state to RRC INACTIVE state. Further, the SDT and multicast session handler (109) receives the at least one multicast session, when the multicast session is activated. Further, the SDT and multicast session handler (109) determines whether a SDT procedure is initiated or ongoing. Further, the SDT and multicast session handler (109) continues to receive the at least one ongoing multicast session, when SDT procedure is initiated or ongoing. Further, the SDT and multicast session handler (109) skip to monitor a paging channel for group paging message that notifies regarding activation of the at least one new multicast session, when the SDT procedure is initiated or ongoing. Further, the SDT and multicast session handler (109) receives while the UE in RRC INACTIVE state, a second RRC release with suspend configuration message that indicates activation of the at least one new multicast session while the SDT procedure is ongoing and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state. Further, the SDT and multicast session handler (109) starts to receive at least one new multicast session in the RRC INACTIVE state.

[0058] FIG. 2 is a block diagram that illustrates a network apparatus for handling SDT and multicast paging, according to the embodiment as disclosed herein.

[0059] The network apparatus (201) includes a processor (203), a memory (207), an I / O interface (205) and a SDT and multicast session handler (209). The network apparatus (201) communicates with the UE (101) for handling SDT and multicast paging. For example, the network apparatus (101) can be, but not limited to a server, a base station, a gNodeB, a 6G NodeB and the like. Further, the processor (203) of the network apparatus (201) communicates with the memory (207), the I / O interface (205) and the SDT and multicast session handler (209). The processor (203) is configured to execute instructions stored in the memory (207) and to perform various processes. The processor (203) can include one or a plurality of processors, can be a general-purpose processor, such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and / or an Artificial intelligence (AI) dedicated processor such as a neural processing unit (NPU).

[0060] Further, the memory (207) of the network apparatus (201) includes storage locations to be addressable through the processor (203). The memory (207) is not limited to a volatile memory and / or a non-volatile memory. Further, the memory (207) can include one or more computer-readable storage media. The memory (207) can include non-volatile storage elements. For example, non-volatile storage elements can include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. Also, the memory (207) of the network apparatus (201) can store several information received from UE (101). For example, the memory (207) can store several information such as a PTM configuration, TMGIs, multicast session activation indication and the like.

[0061] The I / O interface (205) transmits the information between the memory (207) and external peripheral devices. The peripheral devices are the input-output devices associated with the UE (101). The I / O interface (205) receives several information from the UE e.g. the multicast session(s) the UE joins.

[0062] The SDT and multicast session handler (109) communicates with the I / O interface (205) and memory (207) for handling SDT and multicast paging. The SDT and multicast session handler (209) transmits while UE (101) is in Radio Resource Control (RRC) CONNECTED state, the first RRC release with suspend configuration message to indicate the reception of at least one multicast session in RRC INACTIVE state. The first RRC release with suspend configuration message comprises at least one of a multicast Point-To-Multipoint (PTM) configuration. Further, the SDT and multicast session handler (209) transits the UE (101) from RRC CONNECTED state to a RRC INACTIVE state. Further, the SDT and multicast session handler (209) transmits the at least one multicast session, when the multicast session is determined to be activated. Further, the SDT and multicast session handler (209) transmits the at least one ongoing multicast session and a group paging message that notifies regarding activation of the at least one new multicast session. Further, the SDT and multicast session handler (209) determines whether the SDT procedure is at least one initiated, ongoing or completed at the UE and UE is capable of receiving the at least one multicast session in RRC INACTIVE state and UE is in RRC INACTIVE state. Further, the SDT and multicast session handler (209) transmits a second RRC release with suspend configuration message to the UE to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is at least one of initiated or ongoing for the UE and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0063] In an embodiment, transmission and reception of data and / or signalling messages over radio bearers configured for SDT as well as reception of data over multicast MBS radio bearers (MRBs) that are configured for multicast reception in the RRC INACTIVE to the UE (101) (i.e. pertaining to the active MBS sessions), can happen whilst the UE (101) is in RRC INACTIVE state and SDT procedure is ongoing.

[0064] In an embodiment, the UE (101) in RRC INACTIVE state while SDT procedure is ongoing, is only required to acquire broadcastedSIB1andMIBand other MBS specific SIBs (e.g.SIB20 for MCCH configuration for broadcast and / or SIB21 for MBS frequency information and / or SIBxfor multicast MCCH configuration)if the UE (101) can acquire them without disrupting unicast data reception, i.e. the broadcast and unicast beams are quasi co-located.

[0065] In an embodiment, SDT and multicast paging reception in RRC INACTIVE are not configured and / or not operated together for the UE (101).

[0066] In an embodiment, if the cell reselection occurs while the SDT procedure is ongoing and the UE (101) is configured and / or indicated to receive multicast in RRC INACTIVE state and / or UE (101) is actively receiving at least one multicast session in RRC INACTIVE state, the UE (101) continues to be in RRC INACTIVE state. That is, the UE (101) does not go to RRC IDLE state. In an embodiment, an example of proposed specification is provided as follows:

[0067] Example:

[0068] The UE shall:

[0069] 1> if cell reselection occurs while T319 or T302 is running or while SDT procedure is ongoing; or

[0070] 1> if relay reselection occurs while T319 is running; or

[0071] 1> if cell changes due to relay reselection while T302 is running:

[0072] 2> if UE is configured to receive multicast in RRC INACTIVE and / or UE is actively receiving at least one multicast session in RRC INACTIVE:

[0073] 3> continue to stay in RRC INACTIVE;

[0074] 2> else:

[0075] 3> perform the actions upon going to RRC IDLE as specified in 5.3.11 with release cause 'RRC Resume failure'

[0076] In an embodiment, if the cell reselection occurs while the SDT procedure is ongoing and the UE (101) is configured and / or indicated to receive and / or receiving multicast in RRC INACTIVE state, the UE (101) goes to RRC IDLE state. Further, the UE (101) performs the actions upon going to RRC IDLE including release of suspendConfig, discard of the UE (101) Inactive AS context, stopping of all timers except T302, T320, T325, T330, T331, T400 and T430 and other actions typically performed when transiting to RRC IDLE.

[0077] In an embodiment, the UE (101) initiate a transmission of UE assistance information (UAI) message to indicate availability of data and / or signaling mapped to radio bearers which are not configured for the SDT. Further for MBS multicast MRBs, the availability of data and / or signaling may pertain to, for example, a paging response to group paging, a request for RRC state transition and a session release request. Further, the non-SDT-DataIndication or Multicast cause may be indicated in the UAI message. Further, a resumeCause as indicated by the upper layer may be included and set according to the information received from upper layer.

[0078] In an embodiment, when the UE (101) has initiated the SDT procedure and is receiving MBS broadcast and / or MBS multicast in RRC INACTIVE state, the UE continues to be in RRC INACTIVE state, upon successful completion of the SDT procedure. This is to ensure multicast reception in RRC INACTIVE remains intact.

[0079] In an embodiment, when the UE (101) has initiated the SDT procedure and is configured or capable to receive MBS multicast in RRC INACTIVE state and / or UE (101) is actively receiving at least one multicast session in RRC INACTIVE state, the network may direct the UE (101) to be in RRC INACTIVE state, upon successful completion of the SDT procedure (e.g. via RRC Release with suspendConfig or RRCReject). That is, network (201) avoids directing the UE (101) to transit to RRC IDLE and / or RRC CONNECTED state upon completion of SDT procedure. This is to ensure multicast reception in RRC INACTIVE remains intact.

[0080] In an embodiment, when the UE (101) has initiated the SDT procedure and is configured and / or capable to receive MBS multicast in RRC INACTIVE state, the UE (101) does not monitor for group paging for multicast session notification. While the SDT procedure is ongoing, if the at least one multicast session for the UE (101) is activated, the network may determine whether the activated multicast session is to be provided to the UE (101) in RRC INACTIVE state or in RRC CONNECTED state (e.g. on basis of congestion status, UE's reception quality, UE's capability or configuration to receive multicast (or a specific multicast session) in different RRC state). The Network apparatus (201) indicates to the UE (101) about multicast session activation and RRC state where to receive multicast session. RRC state is indicated by sending the kind of message in response e.g. RRC CONNECTED state is indicated to receive multicast session via sending a RRC Resume or a RRC Setup message and RRC INACTIVE state is indicated to receive multicast session via sending a RRC Release with suspendConfig or an RRCReject message. Multicast session activation is indicated by including at least one multicast PTM configuration and / or an activation and / or a corresponding TMGI or a multicast session identity in the pertinent RRC message. In another embodiment, the multicast session activation is indicated by adding a new PTM configuration and / or an activation and / or a corresponding TMGI or a multicast session identity in the pertinent RRC message, that is, the PTM configuration for the already active multicast session(s) for the UE is always provided and UE interprets activation of a multicast session if a new PTM configuration is added to the pertinent RRC message.

[0081] Example:

[0082]

[0083]

[0084] The sessionActivationList is the list of sessions to be activated and continue reception in RRC INACTIVE state. The UE uses the Multicast Configuration provided in inactivePTM-Config as the latest configuration for the activated session. If the latest configuration was not provided in the inactivePTM-Config, UE acquires the MCCH to receive the latest PTM configuration for receiving Multicast in INACTIVE state.

[0085] In an embodiment, the RRCRelease with SuspendConfig during and / or upon completion of SDT procedure carries the group paging records indicating activation of the session for TMGIs in the list and / or indication for whether reception is allowed in RRC INACTIVE state or UE needs to transit to RRC CONNECTED state.

[0086] Example:

[0087]

[0088] In an embodiment, the RRCRelease with SuspendConfig during and / or upon completion of SDT procedure carries inactivePTM-Config indicating latest configuration for TMGIs for the MBS multicast session(s) for the UE (101). UE (101) determines the activation of the TMGIs for the MBS session(s) present in the inactivePTM-Config which are not already activated (i.e. were deactivated sessions) and starts the reception of these multicast session(s) in the RRC INACTIVE state. The activation of multicast session can be indicated with indicating to not stop monitoring of the relevant G-RNTI. UE (101) determines the deactivation of the TMGIs for the MBS session(s) which are not present in the inactivePTM-Config and stops the reception of these multicast session(s) in the RRC INACTIVE state.

[0089] The deactivation of multicast session can be indicated with indicating to stop monitoring of the relevant G-RNTI.

[0090] Example:

[0091]

[0092] In an embodiment, the UE (101) upon receiving the RRCReject message from the network apparatus (201) as a response to the RRCResumeRequest / RRCResumeRequest1 triggered as part of the SDT procedure, and the UE (101) is configured to receive and / or receiving at least one multicast service in RRC INACTIVE state, the UE (101) indicates to upper layer about the failure to resume and / or the list of TMGIs configured / activated for reception in the RRC INACTIVE state. Further, the UE (101) may configure and start receiving the activated multicast sessions. A sample specification text to depict the embodiment is as follows:

[0093] >if RRCReject is received in response to an RRCSetupRequest:

[0094] 2> inform upper layers about the failure to setup the RRC connection, upon which the procedure ends;

[0095] 1> else if RRCReject is received in response to an RRCResumeRequest or an RRCResumeRequest1:

[0096] 2> if resume is triggered by upper layers:

[0097] 3> inform upper layers about the failure to resume the RRC connection;

[0098] 2> if resume is triggered due to an RNA update; or

[0099] 2> if resume is triggered for SDT and T380 has expired:

[0100] 3> set the variable pendingRNA-Update to true;

[0101] 3>if at least one MBS session is configured to be received in RRC INACTIVE state,

[0102] 4> inform upper layers about the failure to resume the RRC connection and / or the list of TMGIs which were configured / activated for reception in RRC INACTIVE state. Further, the UE may configure and start receiving the activated multicast sessions in RRC INACTIVE;

[0103] In an embodiment, upon receiving indication from lower layer that resume request was rejected, the upper layer can initiate a RRC Connection request to regain the multicast services.

[0104] In an embodiment, upon receiving multicast PTM configuration in the RRC Release with suspendConfig or a RRCReject message while the SDT procedure is ongoing, the UE (101) is not required to acquire multicast MCCH and / or validate the received PTM configuration with the configuration present in multicast MCCH message i.e. the multicast PTM configuration in the RRC Release with suspendConfig or a RRCReject message while the SDT procedure is ongoing is considered as latest PTM configuration by the UE (101).

[0105] In an embodiment, UE (101) avails MBS specific SIBs on demand when SDT procedure is on-going. In another embodiment, UE (101) skips availing MBS specific SIBs on demand when SDT procedure is on-going.

[0106] In an embodiment, when the UE (101) has initiated SDT procedure and isconfigured to receive multicast in RRC INACTIVE state and / or UE (101) is actively receiving at least one multicast session in RRC INACTIVE state, upon unsuccessful completion of the SDT procedure, the UE skips transiting to RRC IDLE state. That is, the UE (101) continues to remain in the RRC INACTIVE state. This is to ensure multicast reception in RRC INACTIVE remains intact. The unsuccessful completion of the SDT procedure can be due to at least one of the reasons including cell re-selection, expiry of the SDT failure detection timer, a MAC entity reaching a configured maximum PRACH preamble threshold, an RLC entity reaching a configured maximum retransmission threshold, or expiry of SDT-specific timing alignment timer while SDT procedure is ongoing over Configured Grant (CG) and the UE (101) has not received a response from the network after the initial PUSCH transmission. Further, UE (101) resumes monitoring for the paging channel (e.g. for group paging for the multicast session activation notification).

[0107] In an embodiment, examples of proposed specification is provided for handling of failure to resume RRC connection.

[0108] Example 1:

[0109] 5.3.13.5 Handling of failure to resume RRC Connection

[0110] The UE shall:

[0111] 1> if timer T319 expires:

[0112] <Omitted Text>

[0113] 2> perform the actions upon going to RRC IDLE as specified in 5.3.11 with release cause 'RRC Resume failure'.

[0114] 1> else if upon receiving integrity check failure indication from lower layers while T319 is running:

[0115] 2> perform the actions upon going to RRC IDLE as specified in 5.3.11 with release cause 'RRC Resume failure'.

[0116] 1> else if indication from the MCG RLC that the maximum number of retransmissions has been reached is received while SDT procedure is ongoing; or

[0117] 1> if random access problem indication is received from MCG MAC while SDT procedure is ongoing; or

[0118] 1> if the lower layers indicate that cg-SDT-TimeAlignmentTimer or the configuredGrantTimer expired before receiving network response for the UL CG-SDT transmission with CCCH message while SDT procedure is ongoing; or

[0119] 1> if integrity check failure indication is received from lower layers while SDT procedure is ongoing; or

[0120] 1> if T319a expires:

[0121] 2> consider SDT procedure is not ongoing;

[0122] 2> if UE is configured to receive multicast in RRC INACTIVE and / or UE is actively receiving at least one multicast session in RRC INACTIVE:

[0123] 3> continue to stay in RRC INACTIVE;

[0124] 3> resume monitoring a paging channel (e.g. for paging using TMGI)

[0125] 2> else:

[0126] 3> perform the actions upon going to RRC IDLE as specified In 5.3.11 with release cause 'RRC Resume failure';

[0127] Example 2:

[0128] 5.3.13.5 Handling of failure to resume RRC Connection

[0129] The UE shall:

[0130] <Omitted Text>

[0131] 1> if T319a expires:

[0132] 2> consider SDT procedure is not ongoing;

[0133] 2>if UE is not configured to receive any MBS Multicast session in RRC INACTIVE state,

[0134] 3>perform the actions upon going to RRC IDLE as specified in 5.3.11 with release cause 'RRC Resume failure'

[0135] In an embodiment, upon unsuccessful completion of SDT procedure, indicates to upper layer the RRC Connection resume failure and if configured to receive at least one Multicast session in RRC INACTIVE state, UE (101) AS layer reports the list of TMGIs of Multicast sessions configured for reception in RRC INACTIVE state and performs action upon transition to RRC IDLE.

[0136] In an embodiment, while the SDT procedure is ongoing, if UE (101) is receiving and / or interested to receive MBS multicast session in RRC INACTIVE state, the UE initiates a "multicast reception in RRC INACTIVE indication" using UEAssistanceInformation message to the network and may include the resume cause set as "multicastInRRCInactive"

[0137] In an embodiment, while the SDT procedure is ongoing, if UE (101) is no longer receiving and / or no longer interested to receive multicast session in RRC INACTIVE state, the UE (101) initiates a "no multicast reception in RRC INACTIVE indication" using UEAssistanceInformation message to the network and may include the resume cause set as "no-multicastInRRCInactive"

[0138] In an embodiment, while the SDT procedure is ongoing, if UE (101) intends to release the MBS multicast session(s) (e.g. UE is no longer receiving and / or no longer interested to receive multicast session(s) in RRC INACTIVE state), the UE (101) initiates a "release multicast session(s) indication" using UEAssistanceInformation message to the network and may include the resume cause set as "releasemulticast session". Further, UE (101) may include the TMGI(s) or session identity / identities pertaining to the multicast session(s) to be released. The network apparatus (201) may release the corresponding multicast MRBs and reconfigure the UE (101) accordingly e.g. with a RRCResume message (to move UE to RRC CONNECTED state) or a RRC Release with SuspendConfig message (to move UE to RRC INACTIVE state e.g. if there is at least one more multicast session active for the UE in RRC INACTIVE state) or RRC Release message (to move UE to RRC IDLE state e.g. if the last multicast session is to be released for the UE).

[0139] In an embodiment, while the SDT procedure is ongoing, if UE (101) which is receiving at least one active multicast session in RRC INACTIVE state, intends to move to RRC CONNECTED state (e.g. reception quality for multicast session is below a threshold value in RRC INACTIVE state, serving cell signal strength or signal quality measurement(s) is below a threshold value in RRC INACTIVE state), the UE (101) initiates a "move to RRC CONNECTED request" using UEAssistanceInformation message to the network apparatus (201) and may include the resume cause set as "receptionqualityTriggered". The network apparatus (201) may respond with a RRCResume message (to move UE to RRC CONNECTED state).

[0140] In an embodiment, while the SDT procedure is ongoing, if UE (101) which is receiving at least one active multicast session in RRC INACTIVE state, intends to move to RRC CONNECTED state (e.g. reception quality for multicast session is below a threshold value in RRC INACTIVE state, serving cell signal strength or signal quality measurement(s) is below a threshold value in RRC INACTIVE state), the UE (101) initiates a RRC connection resume procedure to the network apparatus (201) and may include the resume cause set as "receptionqualityTriggered". The network may respond with a RRCResume message (to move UE to RRC CONNECTED state).

[0141] In an embodiment, while the SDT procedure is not ongoing, if UE (101) which is receiving at least one active multicast session in RRC INACTIVE state, intends to move to RRC CONNECTED state (e.g. reception quality for multicast session is below a threshold value in RRC INACTIVE state, serving cell signal strength or signal quality measurement(s) is below a threshold value in RRC INACTIVE state), the UE initiates a RRC connection resume procedure to the network and may include the resume cause set as "receptionqualityTriggered". The network may respond with a RRCResume message (to move UE to RRC CONNECTED state).

[0142] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure the UE (101), which is configured or capable to receive multicast session only in RRC CONNECTED and having at least one non-activated multicast session or expecting data arrival for at least one activated multicast session, may monitor paging channels for RAN-initiated paging and CN-initiated paging for the group paging for multicast session notification e.g. session activation.

[0143] In an embodiment, while in RRCINACTIVE with an ongoing SDT procedure the UE (101), which is configured or capable to receive multicast session only in RRC CONNECTED and having at least one non-activated multicast session or expecting data arrival for at least one activated multicast session, skip monitoring paging channels for RAN-initiated paging and CN-initiated paging for the group paging for multicast session notification e.g. session activation. If group paging is received for relevant session for the UE (101) during the SDT procedure or upon completion of SDT procedure, UE (101) is provided with the RRCResume or RRCSetup message by the network and UE (101) transits to RRC CONNECTED state.

[0144] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure the UE (101), which is configured and / or indicated for multicast reception in RRC INACTIVE state, may monitor paging channels for RAN-initiated paging and CN-initiated paging for the group paging for multicast session notification e.g. session activation and / or an indication to continue reception in RRC INACTIVE, session activation and / or an explicit / implicit indication transition to RRC CONNECTED.

[0145] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure the UE (101), which is configured and / or indicated for multicast reception in RRC INACTIVE state, may monitor MBS control channel (MCCH) e.g. session deactivation, multicast configuration change, PTM configuration for the multicast session or any other notification included in the multicast MCCH message.

[0146] In an embodiment, while in RRCINACTIVE with an ongoing SDT procedure the UE (101), which is configured and / or indicated for multicast reception in RRC INACTIVE state, does not monitor paging channel (e.g. for session activation notification). Instead, UE (101) may monitor multicast MBS control channel (MCCH) and acquire multicast MCCH message for session activation notification. For example, UE (101) determines the activation of the multicast session by checking the presence of the multicast session configuration in the acquired multicast MCCH message.

[0147] In an embodiment, while in RRC INACTIVE with ongoing SDT procedure, the UE (101) which has joined a multicast session, monitors the paging channels in any Paging Occasion (PO) for group paging for multicast session related notification (e.g. session activation). Further, UE (101) may monitor the paging channels in any Paging Occasion at least once in the paging DRX cycle (e.g. RAN paging cycle or default paging cycle).

[0148] In an embodiment, while in RRC INACTIVE with ongoing SDT procedure, the UE (101) which has joined a multicast session, monitors the paging channels in its own Paging Occasion (PO) for group paging for multicast session related notification. The PO for the UE (101) is determined based on the UE ID.

[0149] In an embodiment, while in RRC INACTIVE with ongoing SDT procedure, the UE (101) which has joined a multicast session and is configured to receive multicast in RRC INACTIVE state, monitors the paging channels in any Paging Occasion (PO) which the UE (101) is also using to receive paging for SI change indication, and / or Public Warning System (PWS) indication (e.g. Earthquake Tsunami Warning System (ETWS) or CMAS). Wherein, paging occasion for monitoring group paging determined as the same as the UE (101) is monitoring for SI change indication in any paging occasion at least once per modification period, if the initial downlink BWP on which the SDT procedure is ongoing is associated with a CD-SSB. Wherein, paging occasion for monitoring group paging determined as the same as UE (101) monitor for indication about PWS notification in any paging occasion at least once every defaultPagingCycle, if the initial downlink BWP on which the SDT procedure is ongoing is associated with a CD-SSB.

[0150] In an embodiment, while in RRC INACTIVE with ongoing SDT procedure, the UE (101) which has joined a multicast session and is configured to receive multicast in RRC INACTIVE state, monitors the paging channels in its own Paging Occasion (PO) for group paging for multicast session related notification. The PO for the UE is determined based on the UE ID.

[0151] In an embodiment, while in RRC INACTIVE with ongoing SDT procedure, the UE (101) which has joined a multicast session and is interested to receive multicast in RRC INACTIVE state, monitors the paging channels in its own Paging Occasion (PO) for group paging for multicast session related notification. The PO for the UE (101) is determined based on the UE ID.

[0152] In an embodiment, upon completion of the SDT procedure, the UE (101) resumes monitoring the group paging for session activation if UE (101) has joined the multicast session and / or is configured to receive MBS multicast service in RRC INACTIVE state.

[0153] In an embodiment, if the UE (101) loses interest in or stop receiving a registered / joined multicast session, it can indicate the network to release the session during the ongoing SDT procedure as part of UlInformationTransfer Message.

[0154] In an embodiment, the network signals the release of a multicast session during the ongoing SDT procedure as part of DlInformationTransfer message.

[0155] In an embodiment, if the UE (101) is configured for MBS multicast reception in RRC INACTIVE state, the UE (101) monitors for a paging channel in the RRC INACTIVE state, irrespective of the SDT procedure is ongoing or not. An example specification text is provided as follows:

[0156] Example:

[0157] - RRC INACTIVE:

[0158] - The UE:

[0159] - If configured by upper layers for MBS multicast reception in the RRC INACTIVE, monitors a Paging channel for paging using TMGI, regardless of the SDT procedure is ongoing or not;

[0160] In an embodiment, while in RRC_INACTIVE with an ongoing SDT procedure the UE (101), which is configured or capable to receive multicast session in RRC INACTIVE and having at least one non-activated (or deactivated) multicast session or expecting data arrival for at least one activated multicast session, may monitor a paging channel for the group paging for multicast session notification e.g. session activation or data arrival.

[0161] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, if the UE (101) receives group paging notifying the MBS multicast session activation or data arrival (e.g. with an indication for TMGI(s) for multicast session and / or an Rel-18 indication for reception of multicast session in RRC INACTIVE state in the group paging) to be received in the RRC INACTIVE state, UE (101) stays in RRC INACTIVE and starts monitoring the G-RNTI(s) for multicast session reception for the relevant TMGI(s) as per Rel-18 indication.

[0162] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, if the UE (101) receives the group paging notifying the MBS multicast session notification (e.g. activation or data arrival) to be received in the RRC CONNECTED state (e.g. Rel-17 group paging notification including TMGI(s) for MBS multicast session to be received in the RRC CONNECTED state), the UE (101) ignores the session notification for the relevant TMGI(s). That is, the UE (101) skips the RRC Resumption procedure for relevant TMGI(s) as per Rel-17 message. The UE (101) may rather resume the RRC connection as part of the SDT procedure, based on the network signaling e.g. when RRC Resume message is received from the network.

[0163] In an embodiment, while in RRCINACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, if the UE (101) receives group paging simultaneously (i.e. in the same paging message) notifying the MBS multicast session activation or data arrival (e.g. with an indication for TMGI(s) for multicast session and / or an Rel-18 indication for reception of multicast session in RRC INACTIVE state in the group paging) to be received in the RRC INACTIVE state and notifying the MBS multicast session notification (e.g. activation or data arrival) to be received in the RRC CONNECTED state (e.g. Rel-17 group paging notification including TMGI(s) for MBS multicast session to be received in the RRC CONNECTED state i.e. there is no indication for RRC state), the UE stays in RRC INACTIVE and starts monitoring the G-RNTI(s) for multicast session reception for the relevant TMGI(s) as per Rel-18 indication and the UE skips the RRC Resumption procedure for relevant TMGI(s) as per Rel-17.

[0164] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, the UE (101) ignores or does not process the part of the paging message that is for RAN initiated unicast paging i.e. the paging records in the paging message. Further, UE (101) may not process the paging message that is for RAN initiated unicast paging even when theue-Identityincluded in thePagingRecordmatches the UE's (101) storedfullI-RNTI.That is, the UE (101) only reads and / or processes the group paging part of the paging message pertaining to the TMGI(s).

[0165] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, if the UE (101) receives the RAN paging message notifying a paging indication for the UE (101), the UE (101) ignores the paging message. That is, UE (101) may not process the paging message that is for RAN initiated unicast paging even when theue-Identityincluded in thePagingRecordmatches the UE's (101) storedfullI-RNTI.That is, the UE (101) skips the RRC Resumption procedure. The UE (101) may rather resume the RRC connection as part of the SDT procedure, based on the network signaling e.g. RRC Resume message received form the network apparatus (201).

[0166] In an embodiment, while in RRCINACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, if the UE (101) receives simulateneously (i.e. in the same message) the RAN paging message notifying a paging indication for the UE (101) i.e. theue-Identityincluded in thePagingRecordmatches the UE's (101) storedfullI-RNTIand the TMGI(s) for the multicast session, UE (101) does not process the paging message that is for RAN initiated unicast paging i.e., the UE (101) skips the RRC Resumption procedure and UE (101) process the group paging message that is for multicast reception in RRC INACTIVE state. The UE (101) stays in RRC INACTIVE and starts monitoring the G-RNTI(s) corresponding to theTMGI(s).

[0167] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, the UE (101) ignores or does not process the part of the paging message that is for CN initiated unicast paging i.e. the paging records in the paging message. Further, UE (101) may not process the paging message that is for CN initiated unicast paging even when theue-Identityincluded in thePagingRecordmatches the UE identity allocated by upper layers. That is, the UE (101) only reads and / or processes the group paging part of the paging message.

[0168] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, if the UE (101) receives the CN paging message notifying a paging indication for the UE (101) i.e. theue-Identityincluded in thePagingRecordmatches the UE identity allocated by upper layers, the UE (101) ignores the paging message. That is, the UE (101) skips the transition to the RRC IDLE state.

[0169] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, if the UE (101) receives the CN paging message notifying a paging indication for the UE (101) i.e. theue-Identityincluded in thePagingRecordmatches the UE (101) identity allocated by upper layers, the UE (101) transitions to the RRC IDLE state. Further, UE (101) informs the upper layers for the at least one of paging indication, TMGI(s), UE identity, access Type and paging cause.

[0170] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure and monitoring for group paging for the multicast reception in the RRC INACTIVE, if the UE (101) receives simultaneously (i.e. in the same message) the CN paging message notifying a paging indication for the UE (101) i.e. theue-Identityincluded in thePagingRecordmatches the UE identity allocated by upper layers and the TMGI(s) for the multicast session, the UE transitions to the RRC IDLE state. That is, UE (101) does not avail multicast session reception in the RRC INACTIVE state. Further, UE (101) informs the upper layers for the at least one of paging indication, TMGI(s), UE identity, access Type and paging cause.

[0171] In an embodiment, while in RRC INACTIVE with an ongoing SDT procedure the UE (101), which is configured and / or indicated for multicast reception in RRC INACTIVE state, can monitor MBS control channel (MCCH) e.g. for session deactivation, multicast configuration change, PTM configuration for the multicast session, neighbor cell information change or any other notification included in the multicast MCCH message. Further, UE (101) avoids any resume request that may be triggered due to handling of the multicast MCCH.

[0172] In an embodiment, while in RRC INACTIVE with ongoing SDT procedure, the UE which has joined a multicast session and is configured to receive multicast in RRC INACTIVE state, monitors the paging channels in any Paging Occasion (PO) which the UE (101) is also using to receive paging for SI change indication, and / or Public Warning System (PWS) indication (e.g. Earthquake Tsunami Warning System (ETWS) or Commercial Mobile Alert System (CMAS)). Wherein, paging occasion for monitoring group paging determined as the same as the UE (101) is monitoring for SI change indication in any paging occasion at least once per modification period, if the initial downlink BWP on which the SDT procedure is ongoing is associated with a CD-SSB. Wherein, paging occasion for monitoring group paging determined as the same as UE (101) monitor for indication about PWS notification in any paging occasion at least once everydefaultPagingCycle, if the initial downlink BWP on which the SDT procedure is ongoing is associated with a CD-SSB.

[0173] In an embodiment, while in RRC INACTIVE with ongoing SDT procedure, the UE (101) which has joined a multicast session and is configured to receive multicast in RRC INACTIVE state, monitors for SI change indication, and / or Public Warning System (PWS) indication (e.g. Earthquake Tsunami Warning System (ETWS) or CMAS) in the same paging occasion in which UE (101) monitors for the group paging for the multicast reception in the RRC INACTIVE state. That is, SI change indication and / or PWS notification reception can be allowed or performed along with group paging reception in the same paging occasion.

[0174] In an embodiment, while in RRC_INACTIVE with ongoing SDT procedure, the UE (101) which has joined a multicast session and is interested to receive multicast in RRC INACTIVE state, monitors the paging channels in its own Paging Occasion (PO) for group paging for multicast session related notification. The PO for the UE is determined based on the UE ID.

[0175] In an embodiment, examples of the specification is provided for handling of the paging procedure when the SDT procedure is initiated and / or ongoing for the UE (101) in RRC INACTIVE state.

[0176] Example 1:

[0177] 5.3.2.3 Reception of thePagingmessageby the UE orPagingRecordby the L2 U2N Remote UE

[0178] Upon receiving thePagingmessage by the UE or receivingPagingRecordfrom its connected L2 U2N Relay UE by a L2 U2N Remote UE, the UE shall:

[0179] 1> if in RRC IDLE, for each of thePagingRecord, if any, included in thePagingmessage, or

[0180] 1> if in RRC IDLE, for each of thePagingRecord, if any, included in theUuMessageTransferSidelinkmessage received from the connected L2 U2N Relay UE:

[0181] 2> if theue-Identityincluded in thePagingRecordmatches the UE identity allocated by upper layers:

[0182] 3> if upper layers indicate the support of paging cause:

[0183] 4> forward theue-Identity,accessType(if present) and paging cause (if determined) to the upper layers;

[0184] 3> else:

[0185] 4> forward theue-IdentityandaccessType(if present) to the upper layers;

[0186] 1> if in RRC INACTIVE, for each of thePagingRecord, if any, included in thePagingmessage, or

[0187] 1> if in RRC INACTIVE, for each of thePagingRecord, if any, included in theUuMessageTransferSidelinkmessage received from the connected L2 U2N Relay UE:

[0188] 2> if theue-Identityincluded in thePagingRecordmatches the UE's storedfullI-RNTI:

[0189] 3> if the UE is configured by upper layers with Access Identity 1:

[0190] 4> initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset tomps-PriorityAccess;

[0191] 3> else if the UE is configured by upper layers with Access Identity 2:

[0192] 4> initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset tomcs-PriorityAccess;

[0193] 3> else if the UE is configured by upper layers with one or more Access Identities equal to 11-15:

[0194] 4> initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset tohighPriorityAccess;

[0195] 3> else:

[0196] 4> initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset tomt-Access;

[0197] NOTE: A MUSIM UE may not initiate the RRC connection resumption procedure, e.g. when it decides not to respond to thePagingmessage due to UE implementation constraints as specified in TS 24.501

[0023] .

[0198] 2> else if theue-Identityincluded in thePagingRecordmatches the UE identity allocated by upper layers:

[0199] 3> if upper layers indicate the support of paging cause:

[0200] 4> forward theue-Identity,accessType(if present) and paging cause (if determined) to the upper layers;

[0201] 3> else:

[0202] 4> forward theue-IdentityandaccessType(if present) to the upper layers;

[0203] 3> perform the actions upon going to RRC IDLE as specified in 5.3.11 with release cause 'other';

[0204] 1> if in RRC IDLE, for eachTMGIincluded inpagingGroupList, if any, included in thePagingmessage:

[0205] 2> if the UE has joined an MBS session indicated by theTMGIincluded in thepagingGroupList:

[0206] 3> forward theTMGIto the upper layers;

[0207] 1> if in RRC INACTIVE and the UE has joined one or more MBS session(s) indicated by theTMGI(s)included in thepagingGroupList:

[0208] 2> if the UE is not configured with multicast reception in RRC INACTIVE or ifinactiveReceptionAllowedis not included for at least one of the MBS session (s) that the UE has joined:

[0209] 3>if SDT procedure is not ongoing:

[0210] 4> ifPagingRecordListis not included in thePagingmessage; or

[0211] 4> if none of theue-Identityincluded in any of thePagingRecordmatches the UE identity allocated by upper layers or the UE's storedfullI-RNTI:

[0212] 5> initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset as below:

[0213] 6> if the UE is configured by upper layers with Access Identity 1:

[0214] 7> resumeCause is set to mps-PriorityAccess;

[0215] 6> else if the UE is configured by upper layers with Access Identity 2:

[0216] 7> resumeCause is set to mcs-PriorityAccess;

[0217] 6> else if the UE is configured by upper layers with one or more Access Identities equal to 11-15:

[0218] 7> resumeCause is set to highPriorityAccess;

[0219] 6> else:

[0220] 7> resumeCause is set to mt-Access;

[0221] 4> else if theue-Identityincluded in any of thePagingRecordmatches the UE identity allocated by upper layers:

[0222] 5> forward the TMGI(s) to the upper layers;

[0223] 2> else:

[0224] 3> stay in RRC INACTIVE and start monitoring the G-RNTI(s) corresponding to theTMGI(s);

[0225] 1> if the UE is acting as a L2 U2N Relay UE, for each of thePagingRecord, if any, included in thePagingmessage:

[0226] 2> if theue-Identityincluded in thePagingRecordin thePagingmessage matches the UE identity insl-PagingIdentityRemoteUEincluded insl-PagingInfo-RemoteUEreceived inRemoteUEInformationSidelinkmessage from a L2 U2N Remote UE:

[0227] 3> inititate the Uu Message transfer in sidelink to that UE as specified in 5.8.9.9;

[0228] Example 2:

[0229] 5.3.2.3 Reception of thePagingmessageby the UE orPagingRecordby the L2 U2N Remote UE

[0230] Upon receiving thePagingmessage by the UE or receivingPagingRecordfrom its connected L2 U2N Relay UE by a L2 U2N Remote UE, the UE shall:

[0231] 1> if in RRC IDLE, for each of thePagingRecord, if any, included in thePagingmessage, or

[0232] 1> if in RRC IDLE, for each of thePagingRecord, if any, included in theUuMessageTransferSidelinkmessage received from the connected L2 U2N Relay UE:

[0233] 2> if theue-Identityincluded in thePagingRecordmatches the UE identity allocated by upper layers:

[0234] 3> if upper layers indicate the support of paging cause:

[0235] 4> forward theue-Identity,accessType(if present) and paging cause (if determined) to the upper layers;

[0236] 3> else:

[0237] 4> forward theue-IdentityandaccessType(if present) to the upper layers;

[0238] 1> if in RRC INACTIVE, for each of thePagingRecord, if any, included in thePagingmessage, or

[0239] 1> if in RRC INACTIVE, for each of thePagingRecord, if any, included in theUuMessageTransferSidelinkmessage received from the connected L2 U2N Relay UE:

[0240] 2> if theue-Identityincluded in thePagingRecordmatches the UE's storedfullI-RNTI:

[0241] 3> if the UE is configured by upper layers with Access Identity 1:

[0242] 4> initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset tomps-PriorityAccess;

[0243] 3> else if the UE is configured by upper layers with Access Identity 2:

[0244] 4> initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset tomcs-PriorityAccess;

[0245] 3> else if the UE is configured by upper layers with one or more Access Identities equal to 11-15:

[0246] 4> initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset tohighPriorityAccess;

[0247] 3> else:

[0248] 4> initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset tomt-Access;

[0249] NOTE: A MUSIM UE may not initiate the RRC connection resumption procedure, e.g. when it decides not to respond to thePagingmessage due to UE implementation constraints as specified in TS 24.501

[0023] .

[0250] 2> else if theue-Identityincluded in thePagingRecordmatches the UE identity allocated by upper layers:

[0251] 3> if upper layers indicate the support of paging cause:

[0252] 4> forward theue-Identity,accessType(if present) and paging cause (if determined) to the upper layers;

[0253] 3> else:

[0254] 4> forward theue-IdentityandaccessType(if present) to the upper layers;

[0255] 3> perform the actions upon going to RRC IDLE as specified in 5.3.11 with release cause 'other';

[0256] 1> if in RRC IDLE, for eachTMGIincluded inpagingGroupList, if any, included in thePagingmessage:

[0257] 2> if the UE has joined an MBS session indicated by theTMGIincluded in thepagingGroupList:

[0258] 3> forward theTMGIto the upper layers;

[0259] 1> if in RRC INACTIVE and the UE has joined one or more MBS session(s) indicated by theTMGI(s)included in thepagingGroupList:

[0260] 2> if the UE is not configured with multicast reception in RRC INACTIVE or ifinactiveReceptionAllowedis not included for at least one of the MBS session (s) that the UE has joined:

[0261] 3> ifPagingRecordListis not included in thePagingmessage; or

[0262] 3> if none of theue-Identityincluded in any of thePagingRecordmatches the UE identity allocated by upper layers or the UE's storedfullI-RNTI:

[0263] 4>if SDT procedure is not ongoing,initiate the RRC connection resumption procedure according to 5.3.13 withresumeCauseset as below:

[0264] 5> if the UE is configured by upper layers with Access Identity 1:

[0265] 6> resumeCause is set to mps-PriorityAccess;

[0266] 5> else if the UE is configured by upper layers with Access Identity 2:

[0267] 6> resumeCause is set to mcs-PriorityAccess;

[0268] 5> else if the UE is configured by upper layers with one or more Access Identities equal to 11-15:

[0269] 6> resumeCause is set to highPriorityAccess;

[0270] 5> else:

[0271] 6> resumeCause is set to mt-Access;

[0272] 3> else if theue-Identityincluded in any of thePagingRecordmatches the UE identity allocated by upper layers:

[0273] 4> forward the TMGI(s) to the upper layers;

[0274] 2> else:

[0275] 3> stay in RRC INACTIVE and start monitoring the G-RNTI(s) corresponding to theTMGI(s);

[0276] 1> if the UE is acting as a L2 U2N Relay UE, for each of thePagingRecord, if any, included in thePagingmessage:

[0277] 2> if theue-Identityincluded in thePagingRecordin thePagingmessage matches the UE identity insl-PagingIdentityRemoteUEincluded insl-PagingInfo-RemoteUEreceived inRemoteUEInformationSidelinkmessage from a L2 U2N Remote UE:

[0278] 3> inititate the Uu Message transfer in sidelink to that UE as specified in 5.8.9.9

[0279] FIG. 3A and 3B are a sequence diagram that illustrates an interaction between UE and network apparatus for handling SDT and multicast paging, according to the embodiment as disclosed herein.

[0280] At step S1, the UE (101) receives the RRC release with suspend configuration message from the network apparatus (201). The RRC release with suspend configuration message includes the multicast PTM configuration that indicates that the UE (101) must receive the at least one multicast session in the RRC INACTIVE state.

[0281] At step S2, upon receiving the RRC release with suspend configuration message, the UE (101) transits from the RRC CONNECTED state to the RRC INACTIVE state.

[0282] At step S3, the UE (101) start monitoring a paging channel for group paging message that notifies regarding activation of the at least one multicast session.

[0283] At step S4, the UE (101) receives the at least one multicast session, when the multicast session is activated.

[0284] At step S5, the UE (101) determines whether the SDT procedure is initiated or ongoing.

[0285] At step S6, the network apparatus (201) transmits group paging message while the UE (101) continues to receive the ongoing or initiated multicast session, when the SDT procedure is initiated or ongoing. However, at step S7, the UE (101) skips monitoring the paging channel for the group paging message that notifies regarding activation of the at least one multicast session.

[0286] At step S8, the network apparatus (201) determines whether the at least one multicast session is activated for the UE.

[0287] Also, at step S9, the network apparatus (201) determines whether the UE is capable to receive the multicast session in RRC INATIVE state.

[0288] Further, at step S10, the network apparatus (201) transmits the RRC release with suspend configuration message to indicate the activation of the at least one new multicast session. The new multicast session is the multicast session that is not activated before receiving the second RRC release with suspend configuration message.

[0289] Further, at step S11, upon receiving the UE (101) will at least one of apply PTM configuration, monitor multicast RNTI and acquires multicast MCCH.

[0290] Further, at step S12, the UE (101) receives the new multicast session in the RRC INACTIVE state while the SDT procedure ongoing or initiated. However, the UE (101) skip monitoring the paging channel for the group paging message that notifies regarding activation of the at least one multicast session while the SDT procedure ongoing or initiated. The UE (101) monitors the paging channel for the group paging message that notifies regarding activation of the at least one multicast session if the SDT procedure is completed.

[0291] FIG. 4A and 4B are a flow diagram that illustrates a method for handling SDT and multicast paging, according to embodiments as disclosed herein.

[0292] At block 401, the UE (101) receives RRC release with suspend configuration message and is configured with multicast PTM configuration for receiving multicast in RRC INACTIVE. Further, the UE (101) transits from the RRC CONNECTED state to the RRC INACTIVE state.

[0293] At block 403, the UE (101) receives at least one multicast session, if multicast session is activated and monitors for group paging for multicast session activation.

[0294] Further, at block 405, the UE (101) the UE determines whether SDT procedure is initiated or ongoing.

[0295] Further, at block 407, the UE (101) continues to receive multicast session if activated and also skip monitoring for the group paging while the SDT procedure is initiated or ongoing.

[0296] However, at block 409, the UE (101) continue to receive multicast session if activated and also monitors for group paging when the SDT procedure is not initiated or ongoing.

[0297] Further at block 411, the network apparatus (201) determines whether the multicast session is activated while the SDT procedure is initiated or ongoing, when the UE (101) skips to monitor for group paging message.

[0298] Further, at block 415, the network apparatus (201) determines whether the UE (101) is capable of receiving the multicast session in the RRC INACTIVE state.

[0299] At block 419, the UE (101) receives RRC release message with suspend configuration message with PTM configuration that indicates the activation of the new multicast session, when the multicast session is activated while the SDT procedure is initiated or ongoing and when the UE (101) is capable of receiving the multicast session in the RRC INACTIVE state.

[0300] Further, at block 425, the UE (101) start receiving at least one of the multicast session with PTM configuration, and activation indication. Further, the UE (101) resumes monitoring paging channel for group paging if SDT procedure is completed. The UE (101) skips monitoring paging channel for group paging if SDT procedure is ongoing or initiated.

[0301] At block 413, the network apparatus (201) determines whether the SDT procedure is completed.

[0302] Further, at block 417, the network apparatus (201) determines whether to provide multicast session in RRC INACTIVE state.

[0303] At block 421, the UE (101) receives RRC resume message, when the UE (101) is not capable of receiving the multicast session in the RRC INACTIVE state. Further, the UE (101) transits from the RRC INACTIVE state to the RRC CONNECTED state.

[0304] At block 423, the UE (101) receives RRC release with suspend configuration resume message, when the UE (101) is capable to receive the multicast session in the RRC INACTIVE state. Further, the UE (101) resumes monitoring paging channel for group paging as SDT procedure is completed.

[0305] FIG. 5 is a flow diagram that illustrates a method for handling SDT and multicast paging, according to embodiments as disclosed herein.

[0306] At block 501, while the UE (101) is in RRC INACTIVE state, the UE (101) has configured for SDT and to receive MBS multicast in RRC INACTIVE state.

[0307] Further, at block 503, the UE (101) monitors a paging channel for receiving group paging along with the unicast paging.

[0308] Further, at block 505, the UE (101) determine whether SDT procedure is initiated and / or ongoing.

[0309] At block 507, the UE (101) monitors only for group paging message with an indication to receive MBS multicast in RRC INACTIVE state, when the SDT procedure is initiated or ongoing.

[0310] At block 509, Further, if group paging with RRC INACTIVE reception indication for configured multicast session(s) addressed by TMGI(s) is received, the UE (101) starts reception of multicast session(s) in RRC INACTIVE state.

[0311] However, if the SDT procedure is completed, then the UE (101) monitors a paging channel for receiving group paging along with the unicast paging.

[0312] FIG. 6 is a flow diagram that illustrates a method for handling SDT and multicast paging, according to embodiments as disclosed herein.

[0313] As shown in FIG. 6, At block 601, determining, by the network apparatus (201) whether SDT procedure is initiated and / or ongoing at UE (101) in RRC INACTIVE state,

[0314] Further, when the UE (101) is configured for multicast reception in RRC INACTIVE, at block 603, the UE (101) monitors for paging channel for group paging message during SDT procedure.

[0315] Further, when the UE (101) is not configured for multicast reception in RRC INACTIVE, at block 605, the UE (101) does not monitor for paging channel during the SDT procedure.

[0316] Further, at block 607, if group paging with RRC INACTIVE reception indication for configured multicast session(s) addressed by TMGI(s) is received, the UE (101) starts reception of multicast session(s) in RRC INACTIVE state.

[0317] In an embodiment, at block 607, when a legacy group paging (i.e. no indication for RRC INACTIVE reception) is received, the UE (101) does not initiate a RRC Resume procedure.

[0318] In an embodiment, at block 607, when a unicast paging (e.g. RAN paging and / or CN paging) is received, the UE (101) ignores the UE specific paging and the UE (101) may continue the SDT procedure. However, while SDT procedure is initiated and / or ongoing at the UE (101) in RRC INACTIVE state, and when the UE (101) is not configured for multicast reception in RRC INACTIVE, the UE (101) does not monitor for paging message during SDT procedure (though UE may monitor paging for SI change indication, ETWS indication i.e. short message).

[0319] In an embodiment, the UE (101) monitors the paging channel for group paging for the multicast reception in RRC INACTIVE while SDT procedure is ongoing, wherein the SDT procedure was initiated ifmt-SDTindication was included in the paging message and if the conditions for initiating SDT for a resume procedure initiated in response to RAN paging according to 5.3.13.1b are fulfilled and UE initiated the RRC connection resumption procedure withresumeCauseset tomt-SDT.

[0320] In an embodiment, the UE (101) monitors the paging channel for group paging for the multicast reception in RRC INACTIVE while SDT procedure is ongoing, wherein the SDT procedure was initiated if the conditions for initiating MO-SDT are fulfilled and UE initiated the RRC connection resumption procedure.

[0321] FIG. 7 is a flow diagram that illustrates a method for handling SDT and multicast paging by UE, according to embodiments as disclosed herein.

[0322] At block 701, the method includes receiving, while the UE (101) is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate reception of at least one multicast session in RRC INACTIVE state. The RRC release with suspend configuration message comprises at least one of a multicast PTM configuration.

[0323] At block 703, the method includes transiting from the RRC CONNECTED state to RRC INACTIVE state.

[0324] At block 705, the method includes receiving the at least one multicast session, when the multicast session is activated.

[0325] At block 707, the method includes determining whether the SDT procedure is initiated or ongoing.

[0326] At block 709, the method includes continue receiving the at least one ongoing multicast session, when SDT procedure is initiated or ongoing.

[0327] At block 711, the method includes skips monitoring a paging channel for group paging message that notifies regarding activation of the at least one new multicast session, when the SDT procedure is initiated or ongoing.

[0328] At block 713, the method includes receiving while the UE in RRC INACTIVE state, a second RRC release with suspend configuration message that indicates activation of the at least one new multicast session while the SDT procedure is initiated or ongoing and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0329] At block 715, the method includes starts receiving at least one new multicast session in the RRC INACTIVE state and.

[0330] FIG. 8 is a flow diagram that illustrates a method for handling SDT and multicast paging by network apparatus, according to embodiments as disclosed herein.

[0331] At block 801, the method includes transmitting while UE (101) is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate the reception of at least one multicast session in RRC INACTIVE state. The first RRC release with suspend configuration message comprises at least one of a multicast PTM configuration.

[0332] At block 803, the method includes transiting the UE (101) from RRC CONNECTED state to a RRC INACTIVE state.

[0333] At block 805, the method includes transmitting the at least one multicast session, when the multicast session is determined to be activated.

[0334] At block 807, the method includes transmitting the at least one ongoing multicast session and a group paging message that notifies regarding activation of the at least one new multicast session.

[0335] At block 809, the method includes determining whether the SDT procedure is at least one initiated, ongoing or completed at the UE and UE is capable of receiving the at least one multicast session in RRC INACTIVE state and UE is in RRC INACTIVE state

[0336] At block 811, the method includes transmitting a second RRC release with suspend configuration message to the UE to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is at least one of initiated or ongoing for the UE and the UE is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0337] According to an embodiment of the disclosure, a method for handling Small Data Transmission (SDT) and multicast paging, comprising: receiving, by a User Equipment (UE) (101), while the UE (101) is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate reception of at least one multicast session in RRC INACTIVE state, wherein the RRC release with suspend configuration message comprises at least one of a multicast Point-To-Multipoint (PTM) configuration; transiting, by the UE (101), from the RRC CONNECTED state to RRC INACTIVE state; receiving, by the UE (101), the at least one multicast session, when the multicast session is activated; determining, by the UE (101), whether a SDT procedure is initiated or ongoing; performing at least one of, by the UE (101), continue receiving, by the UE (101), the at least one ongoing multicast session, when SDT procedure is initiated or ongoing; and skip monitoring, by the UE (101), a paging channel for group paging message that notifies regarding activation of the at least one new multicast session, when the SDT procedure is initiated or ongoing; receiving, by the UE (101), while the UE (101) in RRC INACTIVE state, a second RRC release with suspend configuration message that indicates activation of the at least one new multicast session while the SDT procedure is initiated or ongoing and the UE (101) is capable of receiving the at least one multicast session in the RRC INACTIVE state; and start receiving, by the UE (101), at least one new multicast session in the RRC INACTIVE state.

[0338] According to an embodiment of the disclosure, further comprises: performing, by the UE (101), at least one of applying, by the UE (101), PTM configuration received in the second RRC release with suspend configuration message; and monitoring, by the UE (101), multicast MBS Control Channel (MCCH) Radio Network Temporary Identifier (RNTI) and acquiring multicast MCCH; start receiving, by the UE (101), at least one new multicast session in the RRC INACTIVE state and while the SDT procedure is initiated or ongoing; and skip monitoring, by the UE (101), a paging channel for group paging message that notifies regarding activation of the at least one new multicast session activation, when the SDT procedure is initiated or ongoing.

[0339] According to an embodiment of the disclosure, comprises: receiving, by the UE (101), a RRC resume message, while the SDT procedure is initiated or ongoing and the UE (101) is not capable of receiving the at least one multicast session in RRC INACTIVE state; and transiting, by the UE (101), from the RRC INACTIVE state to a RRC CONNECTED state; and receiving, by the UE (101), the at least one multicast session in the RRC CONNECTED state.

[0340] According to an embodiment of the disclosure, further comprises: receiving, by the UE (101), the second RRC release with suspend configuration message while the SDT procedure is completed and the UE is capable of receiving the at least one multicast session in RRC INACTIVE state; and resume monitoring, by the UE (101), paging channel for group paging message in the RRC INACTIVE state that notifies regarding activation of the at least one multicast session activation.

[0341] According to an embodiment of the disclosure, wherein the second RRC release with suspend configuration message comprises at least one multicast PTM configuration for the activated multicast session, an activation indication, or a TMGI or a multicast session identity of the activated multicast session.

[0342] According to an embodiment of the disclosure, wherein the at least one new multicast session is the at least one multicast session that is not activated before receiving the second RRC release with suspend configuration message.

[0343] According to an embodiment of the disclosure, a method for handling Small Data Transmission (SDT) and multicast paging, comprising: transmitting, by a network apparatus (201), while UE (101) is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate the reception of at least one multicast session in RRC INACTIVE state, wherein the first RRC release with suspend configuration message comprises at least one of a multicast PTM configuration; transiting, by the network apparatus (201), the UE (101) from RRC CONNECTED state to a RRC INACTIVE state; transmitting, by the network apparatus (201), the at least one multicast session, when the multicast session is determined to be activated; transmitting, by the network apparatus (201), the at least one ongoing multicast session and a group paging message that notifies regarding activation of the at least one new multicast session; determining, by the network apparatus (201), whether the SDT procedure is at least one initiated, ongoing or completed at the UE (101) and UE (101) is capable of receiving the at least one multicast session in RRC INACTIVE state and UE (101) is in RRC INACTIVE state; transmitting, by the network apparatus (201), a second RRC release with suspend configuration message to the UE (101) to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is at least one of initiated or ongoing for the UE (101) and the UE (101) is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0344] According to an embodiment of the disclosure, comprises: performing, by the network apparatus (201), one of transmitting, by the network apparatus (201), a RRC resume message to provide at least one new multicast session in RRC CONNECTED state and the UE (101) is not capable of receiving the at least one multicast session in the RRC INACTIVE state; or transmitting, by the network apparatus (201), a second RRC release with suspend configuration message to the UE to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is completed and the UE (101) is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0345] According to an embodiment of the disclosure, wherein the second RRC release with suspend configuration message comprises at least one multicast PTM configuration for the activated multicast session, an activation indication, or a TMGI or a multicast session identity of the activated multicast session.

[0346] According to an embodiment of the disclosure, a UE (101) for handling Small Data Transmission (SDT) and multicast paging, comprising: a processor (103); and a SDT and multicast session handler (109) coupled to the processor (103), wherein the SDT and multicast session handler (109) is configured to: receive while the UE (101) is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate reception of at least one multicast session in RRC INACTIVE state, wherein the RRC release with suspend configuration message comprises at least one of a multicast Point-To-Multipoint (PTM) configuration; transit from the RRC CONNECTED state to RRC INACTIVE state; receive the at least one multicast session, when the multicast session is activated; determine whether a SDT procedure is initiated or ongoing;

[0347] perform at least one of continue to receive the at least one ongoing multicast session, when SDT procedure is initiated or ongoing; and skip to monitor a paging channel for group paging message that notifies regarding activation of the at least one new multicast session, when the SDT procedure is initiated or ongoing; receive while the UE (101) in RRC INACTIVE state, a second RRC release with suspend configuration message that indicates activation of the at least one new multicast session while the SDT procedure is initiated or ongoing and the UE (101) is capable of receiving the at least one multicast session in the RRC INACTIVE state; and start to receive at least one new multicast session in the RRC INACTIVE state.

[0348] According to an embodiment of the disclosure, comprises: perform at least one of: apply PTM configuration received in the second RRC release with suspend configuration message; and monitor multicast MBS Control Channel (MCCH) Radio Network Temporary Identifier (RNTI) and acquiring multicast MCCH; start to receive at least one new multicast session in the RRC INACTIVE state and while the SDT procedure is initiated or ongoing; and skip to monitor a paging channel for group paging message that notifies regarding activation of the at least one new multicast session activation, when the SDT procedure is initiated or ongoing.

[0349] According to an embodiment of the disclosure, comprises: receive a RRC resume message, while the SDT procedure is initiated or ongoing and the UE (101) is not capable of receiving the at least one multicast session in RRC INACTIVE state; and transit from the RRC INACTIVE state to a RRC CONNECTED state; and receive the at least one multicast session in the RRC CONNECTED state.

[0350] According to an embodiment of the disclosure, comprises: receive the second RRC release with suspend configuration message while the SDT procedure is completed and the UE (101) is capable of receiving the at least one multicast session in RRC INACTIVE state; and resume to monitor paging channel for group paging message in the RRC INACTIVE state that notifies regarding activation of the at least one multicast session activation.

[0351] According to an embodiment of the disclosure, wherein the second RRC release with suspend configuration message comprises at least one multicast PTM configuration for the activated multicast session, an activation indication, or a TMGI or a multicast session identity of the activated multicast session.

[0352] According to an embodiment of the disclosure, wherein the at least one new multicast session is the at least one multicast session that is not activated before receiving the second RRC release with suspend configuration message.

[0353] According to an embodiment of the disclosure, a network apparatus (201) for handling Small Data Transmission (SDT) and multicast paging, comprising: a processor (203); and a SDT and multicast session handler (209) coupled to the processor (203), wherein the SDT and multicast session handler (209) is configured to: transmit while UE (101) is in Radio Resource Control (RRC) CONNECTED state, a first RRC release with suspend configuration message to indicate the reception of at least one multicast session in RRC INACTIVE state, wherein the first RRC release with suspend configuration message comprises at least one of a multicast PTM configuration; transit the UE (101) form RRC CONNECTED state to a RRC INACTIVE state; transmit the at least one multicast session, when the multicast session is determined to be activated; transmit the at least one ongoing multicast session and a group paging message that notifies regarding activation of the at least one new multicast session; determine whether the SDT procedure is at least one initiated, ongoing or completed at the UE (101) and UE (101) is capable of receiving the at least one multicast session in RRC INACTIVE state and UE (101) is in RRC INACTIVE state; transmit a second RRC release with suspend configuration message to the UE (101) to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is at least one of initiated or ongoing for the UE (101) and the UE (101) is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0354] According to an embodiment of the disclosure, comprises: perform, one of transmit a RRC resume message to provide the at least one new multicast session in RRC CONNECTED state and the UE (101) is not capable of receiving the at least one multicast session in the RRC INACTIVE state; or transmit a second RRC release with suspend configuration message to the UE (101) to indicate the activation of the at least one new multicast session in RRC INACTIVE state when the SDT procedure is completed and the UE (101) is capable of receiving the at least one multicast session in the RRC INACTIVE state.

[0355] According to an embodiment of the disclosure, wherein the second RRC release with suspend configuration message comprises at least one multicast PTM configuration for the activated multicast session, an activation indication, or a TMGI or a multicast session identity of the activated multicast session.

[0356] The various actions, acts, blocks, steps, or the like in the method is performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some of the actions, acts, blocks, steps, or the like are omitted, added, modified, skipped, or the like without departing from the scope of the proposed method.

[0357] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.

[0358]

Claims

1.A method performed by a user equipment (UE) in a wireless communication system, the method comprising:receiving, from a base station, a radio resource control (RRC) release message including first configuration for a RRC inactive state, the first configuration including second configuration associated with multicast reception in the RRC inactive state; andperforming the multicast reception in the RRC inactive state based on the second configuration.2.The method of claim 1, wherein the second configuration includes information on point to multi point (PTM) configuration for the multicast reception in the RRC inactive, the information on the PTM configuration including control information for the multicast reception in the RRC inactive state.3.The method of claim 1, wherein the second configuration includes information on multicast / broadcast service (MBS) control channel (MCCH) configuration for the multicast reception in the RRC inactive.4.The method of claim 3, wherein, in case that information on PTM configuration for the multicast reception in the RRC inactive, which includes control information for the multicast reception in the RRC inactive state, is not included in the RRC release message, the control information for the multicast reception in the RRC inactive state is acquired on the MCCH.5.A method performed by a base station in a wireless communication system, the method comprising:transmitting, to a user equipment (UE), a radio resource control (RRC) release message including first configuration for a RRC inactive state, the first configuration including second configuration associated with multicast reception in the RRC inactive state; andperforming the multicast transmission to the UE in the RRC inactive state based on the second configuration.6.The method of claim 5, wherein the second configuration includes information on point to multi point (PTM) configuration for the multicast reception in the RRC inactive, the information on the PTM configuration including control information for the multicast reception in the RRC inactive state.7.The method of claim 5, wherein the second configuration includes information on multicast / broadcast service (MBS) control channel (MCCH) configuration for the multicast reception in the RRC inactive.8.The method of claim 7, wherein, in case that information on PTM configuration for the multicast reception in the RRC inactive, which includes control information for the multicast reception in the RRC inactive state, is not included in the RRC release message, the control information for the multicast reception in the RRC inactive state is acquired on the MCCH.9.A user equipment (UE) in a wireless communication system, the UE comprising:a transceiver; anda controller coupled with the transceiver and configured to:receive, from a base station, a radio resource control (RRC) release message including first configuration for a RRC inactive state, the first configuration including second configuration associated with multicast reception in the RRC inactive state, andperform the multicast reception in the RRC inactive state based on the second configuration.10.The UE of claim 9, wherein the second configuration includes information on point to multi point (PTM) configuration for the multicast reception in the RRC inactive, the information on the PTM configuration including control information for the multicast reception in the RRC inactive state.11.The UE of claim 9, wherein the second configuration includes information on multicast / broadcast service (MBS) control channel (MCCH) configuration for the multicast reception in the RRC inactive.12.The UE of claim 11, wherein, in case that information on PTM configuration for the multicast reception in the RRC inactive, which includes control information for the multicast reception in the RRC inactive state, is not included in the RRC release message, the control information for the multicast reception in the RRC inactive state is acquired on the MCCH13.A base station in a wireless communication system, the base station comprising:a transceiver; anda controller coupled with the transceiver and configured to:transmit, to a user equipment (UE), a radio resource control (RRC) release message including first configuration for a RRC inactive state, the first configuration including second configuration associated with multicast reception in the RRC inactive state, andperform the multicast transmission to the UE in the RRC inactive state based on the second configuration.14.The base station of claim 13, wherein the second configuration includes information on point to multi point (PTM) configuration for the multicast reception in the RRC inactive, the information on the PTM configuration including control information for the multicast reception in the RRC inactive state.15.The base station of claim 13, wherein the second configuration includes information on multicast / broadcast service (MBS) control channel (MCCH) configuration for the multicast reception in the RRC inactive.

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