Core network enhancements to enable MBS over ntn

Abstract

Embodiments of the present disclosure provide solutions for core network (CN) enhancements to enable multicast and broadcast services (MBS) over non-terrestrial network (NTN). In an example method, a network device transmits a request to create a MBS session comprising a service area of the MBS session and at least one of: an indication that the MBS session is to be provided via an NTN; an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell ID to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of the MBS session; a service area description of the MBS session including a small MBS service area list or a mapped cell ID; or a satellite ID.

Description

CORE NETWORK ENHANCEMENTS TO ENABLE MBS OVER NTNFIELD

[0001] Example embodiments of the present disclosure generally relate to the field of communication, and in particular, to network devices, methods, apparatuses, and computer readable media for core network (CN) enhancements to enable multicast and broadcast services (MBS) over non-terrestrial network (NTN).BACKGROUND

[0002] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network. Such communication networks operate in accordance with standards, such as those promulgated by 3 GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of such standards include the so-called 5G (5th Generation) standard or other standards promulgated by 3GPP.SUMMARY

[0003] In general, embodiments of the present disclosure provide solutions for core network (CN) enhancements to enable multicast and broadcast services (MBS) over nonterrestrial network (NTN).

[0004] In a first aspect, there is provided a first network device. The first network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the first network device at least to: transmit, to a second network device, a request to create a Multicast and Broadcast Services (MBS) session comprising a service area of the MBS session and at least one of: an indication that the MBS session is to be provided via a non-terrestrial network (NTN); an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell identity (ID) to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of the MBS session; a service area description of the MBS session, wherein the service area description includes a small MBS service area list; a service area descriptionof the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID.

[0005] In a second aspect, there is provided a second network device. The second network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the second network device at least to: receive, from a first network device, a request to create a Multicast and Broadcast Services (MBS) session that is to be provided via a non-terrestrial network (NTN) comprising a service area of the MBS session; and transmit, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: a small MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

[0006] In a third aspect, there is provided a third network device. The third network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the third network device at least to: receive, from a second network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising a small MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; select an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and send a request to start an MBS session to the selected AMF.

[0007] In a fourth aspect, there is provided a method comprising: transmitting, from a first network device and to a second network device, a request to create a Multicast and Broadcast Services (MBS) session comprising a service area of the MBS session and at least one of: an indication that the MBS session is to be provided via a non-terrestrial network (NTN); an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell identity (ID) to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of the MBS session; a service area description of the MBSsession, wherein the service area description includes a small MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID.

[0008] In a fifth aspect, there is provided a method comprising: receiving, from a first network device and at a second device, a request to create a Multicast and Broadcast Services (MBS) session that is to be provided via a non-terrestrial network (NTN) comprising a service area of the MBS session; and transmitting, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: a small MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

[0009] In a sixth aspect, there is provided a method comprising: receiving, from a second network device and a third network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising a small MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; selecting an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and sending a request to start an MBS session to the selected AMF.

[0010] In a seventh aspect, there is provided an apparatus comprising: means for means for transmitting, from a first network device and to a second network device, a request to create a Multicast and Broadcast Services (MBS) session comprising a service area of the MBS session and at least one of: an indication that the MBS session is to be provided via a nonterrestrial network (NTN); an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell identity (ID) to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of the MBS session; a service area description of the MBS session, wherein the service area description includesa small MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID.

[0011] In an eighth aspect, there is provided an apparatus comprising: means for receiving, from a first network device and at a second device, a request to create a Multicast and Broadcast Services (MBS) session that is to be provided via a non-terrestrial network (NTN) comprising a service area of the MBS session; and means for transmitting, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: a small MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

[0012] In an ninth aspect, there is provided an apparatus comprising: means for receiving, from a second network device and a third network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising a small MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; means for selecting an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and means for sending a request to start an MBS session to the selected AMF.

[0013] In a tenth aspect, there is provided a computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least: transmitting, from a first network device and to a second network device, a request to create a Multicast and Broadcast Services (MBS) session comprising a service area of the MBS session and at least one of: an indication that the MBS session is to be provided via a non-terrestrial network (NTN); an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell identity (ID) to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of the MBS session; a service area description of the MBS session, wherein the service area description includesa small MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID.

[0014] In a eleventh aspect, there is provided a computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least: receiving, from a first network device and at a second device, a request to create a Multicast and Broadcast Services (MBS) session that is to be provided via a non-terrestrial network (NTN) comprising a service area of the MBS session; and transmitting, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: a small MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

[0015] In a twelfth aspect, there is provided a computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least: receiving, from a second network device and a third network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising a small MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; selecting an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and sending a request to start an MBS session to the selected AMF.

[0016] In a thirteenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: transmitting, from a first network device and to a second network device, a request to create a Multicast and Broadcast Services (MBS) session comprising a service area of the MBS session and at least one of: an indication that the MBS session is to be provided via a non-terrestrial network (NTN); an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell identity (ID) to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of the MBS session; a service areadescription of the MBS session, wherein the service area description includes a small MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID.

[0017] In a fourteenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: receiving, from a first network device and at a second device, a request to create a Multicast and Broadcast Services (MBS) session that is to be provided via a non-terrestrial network (NTN) comprising a service area of the MBS session; and transmitting, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: a small MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

[0018] In a fifteenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: receiving, from a second network device and a third network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising a small MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; selecting an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and sending a request to start an MBS session to the selected AMF.

[0019] In a sixteenth aspect, there is provided a first network device. The first network device comprises: a transmitting circuitry configured to transmit, to a second network device, a request to create a Multicast and Broadcast Services (MBS) session comprising a service area of the MBS session and at least one of: an indication that the MBS session is to be provided via a non-terrestrial network (NTN); an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell identity (ID) to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of theMBS session; a service area description of the MBS session, wherein the service area description includes a small MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID.

[0020] In a seventeenth aspect, there is provided a second network device. The second network device comprises: a receiving circuitry configured to receive, from a first network device, a request to create a Multicast and Broadcast Services (MBS) session that is to be provided via a non-terrestrial network (NTN) comprising a service area of the MBS session; and a transmitting circuitry configured to transmit, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: a small MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

[0021] In an eighteenth aspect, there is provided a third network device. The third network device comprises: a receiving circuitry configured to receive, from a second network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising a small MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; a selecting circuitry configured to select an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and a transmitting circuitry configured to send a request to start an MBS session to the selected AMF.

[0022] It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Some embodiments will now be described with reference to the accompanying drawings, in which:

[0024] FIG. 1 illustrates an example network environment in which some embodiments of the present disclosure can be implemented;

[0025] FIG. 2 illustrates an example of a process flow in accordance with some embodiments of the present disclosure;

[0026] FIGS. 3 to 6 illustrate process flows of MBS session creation in accordance with some embodiments of the present disclosure;

[0027] FIG. 7 illustrates an example flowchart of a method implemented at a first network device according to embodiments of the present disclosure;

[0028] FIG. 8 illustrates an example flowchart of a method implemented at a second network device according to embodiments of the present disclosure;

[0029] FIG. 9 illustrates an example flowchart of a method implemented at a third network device according to embodiments of the present disclosure;

[0030] FIG. 10 illustrates an example simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure; and

[0031] FIG. 11 illustrates an example block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

[0032] Throughout the drawings, the same or similar reference numerals represent the same or similar elements.DETAILED DESCRIPTION

[0033] Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

[0034] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0035] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0036] It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0038] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) with software / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor s), that requires software (for example, firmware) for operation, but the software may not be present when it is not needed for operation.

[0039] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0040] As used herein, the term “network”, “communication network” or “data network” refers to a network following any suitable communication standards, such as long term evolution (LTE), LTE-advanced (LTE-A), wideband code division multiple access (WCDMA), high-speed packet access (HSPA), wireless fidelity (Wi-Fi), narrow band Internet of things (NB-IoT), satellite, enhanced machine-type communication (eMTC), nonterrestrial communication, terrestrial communication, and so on. Furthermore, the communications between a terminal device and a network device / element in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the fourth generation (4G), 4.5G, the fifth generation (5G), the sixth generation (6G), new radio (NR), IEEE 802.11 communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the presentdisclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0041] As used herein, the term “network device” may refer to a device comprising or performing a core network function. For instance, a network device may refer to a device comprising or performing network functions, including but not limited to, Access and Mobility Management Function (AMF), Session Management Function (SMF) such as a multicast and broadcast SMF (MB-SMF), Application Function (AF), Network Exposure Function (NEF), a Multicast and Broadcast Services Function (MBSF), a MBS Transport Function (MBSTF), Policy Control Function (PCF), Unified Data Managem ent / Repository (UDM / UDR), a Network Repository Function (NRF), a User Plane Function (UPF) such as multicast and broadcast UPF (MB-UPF), among others things.

[0042] It is understood that references in the above to various network functions (e.g., an SMF, an NEF, an MBSF, an AF etc.) may be implemented by apparatus (e.g., network apparatus) that performs at least some of the functionality associated with those network functions. Further, an apparatus configured to implement a network function may further be configured to implement a virtual network function instance of that network function.

[0043] In some embodiments, the apparatus may be or comprise a network function, such as an SMF, an NEF, an MBSF, an AF, etc. In the present disclosure, an apparatus being / comprising a network function refers to an apparatus / device configured to provide / perform at least part of functionalities of that network function.

[0044] The term “network device” may refer also to a network node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) or a transmission and reception point (TRP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR NB (also referred to as a gNB), a remote radio unit (RRU), a radio header (RH), a remote radio head (RRH), a WiFi (Wireless Fidelity) device, a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. In the following description, the terms “network device”, “AP device”, “AP” and “access point” may be used interchangeably.

[0045] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a subscriber station (SS), aportable subscriber station, a mobile station (MS), a station (STA) or station device, or an access terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (for example, remote surgery), an industrial device and applications (for example, a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. In the following description, the terms “station”, “station device”, “STA”, “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0046] The term “transceiver” may refer to any device that may be coupled to one or more antennas or antenna ports to wirelessly transmit and / or receive communication signals. The antennas or antenna ports may be the same or different types. The antennas or antenna ports may be located in different positions of an apparatus. One or more transceivers allow the apparatus to communicate with other devices that may be wired and / or wireless. The one or more transceivers may include processors, controllers, radios, sockets, plugs, buffers, or the like circuits to form one or more communication channels to one or more radio frequency units. The one or more transceivers may be integrated in an apparatus or a system, for example a cellular communication apparatus or system, a satellite communication apparatus or system, a WLAN system, or a short ranging system for example Bluetooth system.

[0047] FIG. 1 illustrates an example network environment in which some embodiments of the present disclosure can be implemented. As shown in FIG. 1, the network environment may include UE, a NG-RAN (e.g., a base station such as gNB), and core network (CN) entities including various Network Functions (NFs). The NFs include but not limited to: AMF, SMF, UDM, NRF, PCF, NEF, UPF, AF and Multicast and Broadcast Services (MBS) related NFs, including MB-SMF, MBSF, MB-UPF, and MBSTF.

[0048] The AMF is used for handling access and mobility management tasks related to the UE 110. This includes user registration, connection management, and mobility management as the user moves between different cells. The AMF can interact with other network functions, including the UDM for subscription data and the SMF for session management. The AMF may communicate with the NG-RAN node via N2 interface, and with the UE 110 via N1 interface using Non Access Stratum (NAS) messages.

[0049] The SMF is responsible for managing user sessions in the network. The SMF can interacts with the AMF for session setup requests and with the UPF via N4 interface for data forwarding.

[0050] The NRF serves to support the dynamic management and discovery of network functions (NFs) within the core network, including function registration, function discovery, dynamic management and others. The NEF is used to facilitate the exposure of network capabilities and services to third-party applications, ensuring secure and efficient interactions. The NEF can interface with various network functions, including the AF for specific application-related services, and the NRF for discovering available network services.

[0051] The UDM is responsible for managing subscriber-related data, including user profiles, authentication information, and subscription detail. The UDM may interact with the AMF for user authentication and the NEF for providing subscriber data. The UDR 185 may serve as a storage system for all types of subscriber data, including service-related information and other operational data.

[0052] The PCF can manage and enforce policy rules related to Quality of Service (QoS), resource allocation, and overall service delivery for users and applications. It may interact with the SMF to provide QoS parameters for session establishment and management, with the UDM to access subscriber-related information for policy decisions, and with the NEF to share policy information with external applications and services.

[0053] The UPF is responsible for handle user data traffic, enabling transmission of the flow of data between the UE and data network (DN) such as the Internet or private networks. The UPF may interface with the SMF for session-related commands and control, and with the DN to facilitate user data flow to external networks.

[0054] Among the MBS related NFs, the MB-SMF manages the setup, maintenance, and release of MBS sessions in network. It ensures that MB services are correctly configured, updated, and terminated, coordinating with other network functions like the MB-UPF tohandle user data flows. The MBSF is responsible for the overall management of MBS sessions. It coordinates with other network entities, particularly for managing the configuration and delivery of broadcast content to users. The MBSF handles the creation and distribution of the content to the appropriate networks and end users. The MB-UPF responsible for the actual data forwarding and delivery of multicast or broadcast content to end-users. The MBSTF manages tasks related to MBS delivery, including resource management and optimization, session monitoring, ensuring that multicast or broadcast content reaches end users with minimal delays and proper network conditions.

[0055] 3GPP has finalized a work item for support of Multicast and Broadcast Services (MBS) in Release 17 New Radio (NR). Herein, Point to Multi-Point (PTM) transmission is expected to efficiently provision MBS services to multiple users by using the same radio framework as unicast transmission. Rel-17 enabled the reception of a multicast service by the UEs in RRC CONNECTED state, only, and reception of a broadcast service by UEs in all RRC states.

[0056] The broadcast service is an alternative to the multicast service that does not consider UE locations to determine where to provide the service, but that enables the reception by UEs in all RRC states. Unlike for an MBS multicast session, the usage of a specific service announcement related to the MBS broadcast service and PLMN is required and only the Temporary Mobile Group Identity (TMGI) is supported as identifier of the MBS broadcast session.

[0057] In order for the UE to receive the MBS broadcast in the RRC IDLE / RRC INACTIVE mode, SIB20 includes the necessary information for the UE to receive the Multicast Control Channel (MCCH) information including the repetition period and configured transmission / reception window of MCCH.

[0058] The MCCH information, that is the control information for the UE to understand which broadcast services are provided in the cell and the scheduling information to receive the broadcasted data (see TS 38.331 Sec. 5.9), is transmitted periodically by a gNB using a configurable repetition period and within a configured transmission window. MCCH provides information about the Multicast Traffic Channels (MTCHs) (the data channels where the broadcast services are provided). This information includes search spaces, discontinuous reception (DRX) information, etc. for the UE to be able to receive the relevantMTCH(s). Each TMGI - which is an identifier of a specific broadcast service - is mapped to a specific MTCH.

[0059] The UE reads and decodes the SIB20 message and learns the MCCH configuration / scheduling details. Then the UE reads the MCCH to learn about which services are provided in the cell and their scheduling information. For the UEs in RRC CONNECTED mode, SIB reading is bypassed, as the UE is provided with the search space configuration to receive MCCH within PDCCH ConfigCommon.

[0060] For broadcast, a UE receives via service announcement of an MBS service (that can be transmitted via unicast or using another broadcast session) Frequency Selection Area ID(s) applicable to that MBS service, MBS service area and TMGI information. MBS service area can be provided as a list of T tracking area Identities (TAIs) and / or cell IDs or geographical area information.

[0061] 3GPP TS 38.300, Clause 16.14, describes principles for a Non-Terrestrial Network (NTN) radio network. A Non-Terrestrial Network (NTN) may provide non-terrestrial NR access to the UE by means of an NTN payload and an NTN Gateway, using a service link between the NTN payload and the UE, and a feeder link between the NTN Gateway and the NTN payload.

[0062] The NTN payload transparently forwards the radio protocol received from the UE (via the service link) to the NTN Gateway (via the feeder link) and vice-versa. The following connectivity is supported by the NTN payload: an NTN gateway may serve multiple NTN payloads and an NTN payload may be served by multiple NTN gateways. The NTN-payload may change the carrier frequency, before re-transmitting it on the service link, and vice versa (respectively on the feeder link).

[0063] For NTN, the following applies in addition to Network Identities as described in clause 8.2:A Tracking Area corresponds to a fixed geographical area. Any respective mapping is configured in the RAN;A Mapped Cell ID as specified in clause 16.14.5.

[0064] Three types of service links are supported:Earth-fixed: provisioned by beam(s) continuously covering the same geographical areas all the time (e.g., the case of GSO satellites);Quasi -Earth-fixed: provisioned by beam(s) covering one geographic area for a limited period and a different geographic area during another period (e.g., the case of NGSO satellites generating steerable beams);Earth-moving: provisioned by beam(s) whose coverage area slides over the Earth surface (e.g., the case of NGSO satellites generating fixed or non-steerable beams).

[0065] With NGSO satellites, the gNB can provide either quasi -Earth-fixed service link or Earth-moving service link, while gNB operating with GSO satellite can provide Earth fixed service link. The UE supporting NTN is GNSS-capable. In NTN, the distance refers to Euclidean distance.

[0066] It was suggested that the functionality of MBS is extended to include Release 19 NTN support, wherein the gNB is carried on the satellite. MBS feature provides an important add-value for NR NTN system, leveraging the large coverage of the NTN compared to TN. Terrestrial MBS features are equally available for NR NTN in the 5G specifications, but for some cases the intended service area is expected to be smaller than the coverage of a Uu cell, some enhancements need to be done to notify the service area of a Broadcast service.

[0067] It was suggested to specify signaling of the intended service area of a broadcast service (e.g. MBS broadcast) via NR NTN, including SIB signaling to indicate the intended service area in case the satellite footprint covers a larger area and the necessary signaling between CN and NG-RAN.

[0068] Since the NTN cell (satellite footprint) can be large in size (might be covering whole city or even a country), the UEs in this area needs to understand for which sub-area the MBS broadcast is intended a.k.a. ‘intended service area of a broadcast service’. The NR NTN may indicate the UE about the intended broadcast service area in case the satellite footprint covers a larger area. For example, the intended broadcast service area is a small geographical area of a Uu cell’s coverage. To accomplish this, it was agreed two options to provide intended broadcast service area to the UEs.

[0069] Option 1 : CN maps the intended service area to TAI, or / and cell ID, where Mapped Cell ID is used since Mapped Cell ID is associated with a fixed geographical area. The gNB translate the received TAI and / or Mapped Cell ID to the intended service area info and send to UE. This option does not change NGAP and CN.

[0070] Option 2: CN send the TAI and / or cell ID, and the new intended service area info to gNB. The gNB transparently forward the received intended service area info to UE. Theformat of the intended service area info aligns with RAN2 format. This option requires new IE in NGAP and affects CN nodes.

[0071] The intended service area may be in a form of cell ID list, TAI list, or the geographic area or any combination. The UE can be provided with intended service area in form of geographical location (e.g. GNSS etc). For Option 2, along with traditional TAI, or / and cell ID, the new intended service area is denoted as ‘MBS Service Area Small Area List. In this disclosure, the smaller intended service area of a broadcast service for option 2 may be referred to as a small MBS Service Area List.

[0072] In addition, a satellite broadcasts MBS session in whole cell area that it is serving. The UE should check the intended service area and receive MBS service if it in this area. UE outside the intended service area can still receive the MBS service being broadcasted which cannot be avoided. A specific geographical location may be mapped to multiple Mapped Cell ID(s), and such Mapped Cell IDs may be configured to indicate different geographical areas (e.g. overlapping and / or with different dimensions).

[0073] Currently NEF / MBSF translates (in case AF is not in trust domain and area provided in form of geographical area(s) or civic address(es)) or provides the MBS service area as a list of Tracking Area Identifier TAI(s) and / or cell ID(s). This information is provided by NEF / MBSF to MB-SMF and then to AMF which is finally given to NG RAN node. Based on the recent RAN3 agreements, in case the MBS service is now to be provided with NTN, the RAN nodes should be able to provide information towards the UEs, indicating that the “intended” service area is smaller than cell granularity in this cell for a specific service.

[0074] In this disclosure, the NEF / MBSF may translate or provide the received geographical area(s) or civic address(es) from AF. In Option 1, the NEF / MBSF translates the received geographical area(s) or civic address(es) to TAI, or / and cell ID, where cell ID is Mapped Cell ID (this is cell ID associated with a fixed geographical area). In option 2, the NEF / MBSF translates the received geographical area(s) or civic address(es) to, along with TAI and / or cell ID, small MBS Service Area List, where each small area is smaller than a cell and could be denoted for instance by a geographical description (e.g. in the form of a circle denoted by coordinates of the center plus radius).

[0075] The MB-SMF selects AMFs based on the service area information, and the AMFs in turn select NR-RAN nodes based on that information. The following related issues need to be considered.

[0076] One issue is that the MB-SMF and AMFs so far are not capable of using small area list for the selection and it seems desirable to avoid that they need new related extensive configured information.

[0077] Another issue is that normal Cell IDs contain NG RAN node IDs and the selection based on Cell IDs likely considers those contained NG RAN node IDs. However, mapped cell IDs do not contain such NG RAN node IDs as they can denote different physical cells (that can be handled by different RAN nodes) at different points in time. It should be avoided that MB-SMFs need to map mapped cell IDs to physical cell IDs. This is rather functionality expected in AMFs and / or NG RAN nodes. Thus, the MB-SMF should obtain TAIs together with mapped cell IDs to enable the MB-SMF to select appropriate AMFs and route related requests towards them. However, the existing semantics of TAIs in MB-SMF service areas are that the entire TAIs are in the MB-SMF service area, which likely is not appropriate if mapped cell IDs are included.

[0078] Furthermore, the signaling extensions described above are only applicable for NTN transport and shall otherwise not be used, and the determination which of Options 1 or 2 above to use is required.

[0079] According to embodiments of the present disclosure, for NTN, an MBS service area may be denoted in the 5GC and towards NG-RAN via mapped Cell IDs. If mapped cell IDs are provided, routing TAIs for the mapped cell IDs shall be provided for them to enable an MB-SMF to select AMFs and for an AMF to select NG-RAN nodes.

[0080] Additionally or alternatively, for NTN, an MBS service areas can also be denoted in the 5GC with a small area list that is provided in combination with TAIs and / or cell IDs, for instance to denote a MBS service area smaller than cells. The small area list may be used to further restrict the area denoted by TAIs and / or cell IDs. Then, the MB-SMF may select AMFs based on TAIs and / or cell IDs, and the AMF may in turn select NG-RAN nodes (gNBs) based TAIs and / or cell IDs. The mapped cell IDs, routing TAIs, small area list, TAIs and / or cell IDs are either provided by the AF or derived by the NEF / MBSF.

[0081] FIG. 2 illustrates an example of a process flow 200 in accordance with some embodiments of the present disclosure. For ease of understanding, the process flow 200 willbe described with reference to FIG. 1. It would be appreciated that the process flow 200 may be likewise applied to other similar communication scenarios.

[0082] The process flow 200 involves a first network device 210, a second network device 220 and a third network device 230. In some embodiments, the first network device 210 may be or comprise the AF in FIG. 1. The second network device 220 may be or comprise one or more of the NEF orthe MBSF in FIG. 1. The third network device 230 may be or comprise MB-SMF in FIG. 1. It is understood that more entities or devices can be involved in the process flow 200.

[0083] At 201, the first network device 210 transmits a request 202 to create a MBS session to the second network device 220. Correspondingly, the second network device 220 receives the request 202. The request 202 may comprise a service area of the MBS session. The MBS session may be a broadcast session.

[0084] It is assumed that the first network device 210 knows whether the MBS session will be delivered over TN or NTN (or both NTN and TN). The request 202 may further comprise at least one of: an indication that the MBS session is to be provided via a NTN; an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell identity (ID) to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of the MBS session; a service area description of the MBS session, wherein the service area description includes a small MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID.

[0085] In this way, the request 202 provides how to determine the service area description. The second network device 220 may determine the service area description of the MBS session using the received information information on how to determine the service area description.

[0086] In some embodiments, the first network device 110 may further send an MBS session announcement for the MBS session towards at least one UE. The session announcement may comprise one or more of: an indication that the MBS session is to be provided via the NTN; an indication that the service area of the MBS session is smaller than a cell level granularity; a service area description of the MBS session, wherein the servicearea description includes a small MBS service area list; or a service area description of the MBS session, wherein the service area description includes a mapped cell ID.

[0087] The first network device 210 may indicate that an MBS session is meant to be transported via NTN when requesting the creation of an MBS session and providing an MBS service area. The second network device 220 then uses the service area received from the first network device 210 to derive and provide service area description, including one or more of mapped cell IDs, routing TAIs, and or a small area list in signaling towards the 5GC based on that indication.

[0088] In some embodiments, the first network device 210 may indicate that an MBS session requires mapped cell IDs and / or a small area list when requesting the creation of an MBS session and providing an MBS service area. The second network device 220 then uses the service area received from the first network device to derive and provides mapped cell IDs, routing TAIs, and / or a small area list in signaling towards the 5GC based on that indication.

[0089] In some embodiments, when the second network device 220 receives the request 202 to create an MBS session for an MBS service area from the first network device 210, the second network device 220 may derive, based on configured information, that the MBS session is meant to be transported via NTN, and derive and provides mapped cell IDs, routing TAIs, and or a small area list in signaling towards the 5GC.

[0090] In some embodiments, the indication that MBS session is to be provided via the NTN also indicates that the MBS session is also to be provided via a terrestrial network (TN). When the MBS session is delivered over both NTN and TN, then the MBS service area can be translated by the second network device 220 to the service are description that contains both mapped cell IDs (associated with the NTN) and TAI list / cell Ids (associated with TN).

[0091] In some embodiments, the first network device, if in trusted domain, may indicate satellite ID(s) (e.g. GEO satellite) that provides the MBS service. Additionally or alternatively, the second network device 220 may derive the associated satellite ID(s) based on the MBS service area and the indication that MBS session is to be delivered via NTN only from the first network device 210.

[0092] At 204, the second network device 220 transmits a request 205 to create the MBS session to the third network device 230. Correspondingly, at 206, the third network device 230 receives the request 205 from the second network device 220.

[0093] The request 205 may comprise a service area description of the MBS session derived from the received service area of the MBS session. The service area description of the MBS session may include a small MBS service area list in combination with a related Cell Identifier or TAI, wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided. Additionally or alternatively, the service area description may include a mapped cell identity.

[0094] As mentioned, the request 202 from the first network device 210 may provide the information on how to determine the service area description. Therefore, the second network device 220 can determine the service area description based on the request 202 from the first network device 210.

[0095] In some embodiments, the second network device 220 may determine, based on the identity of the first network device or the received service area of the MBS session, that the MBS session is to be is to be provided via the NTN. Based the determination, the second network device 220 may include in the transmitted service area description at least one of the small MBS service area list in combination with the related Cell Identifier or TAI; or the mapped cell identity.

[0096] In some embodiments, the receive service area that includes a mapped cell ID may also include at least one routing TAI for the mapped cell ID, and the transmitted service area description that includes the mapped cell ID may also include the at least one routing TAI.

[0097] In some embodiments, the received indication that the MBS session is to be provided via a NTN may also indicate that the MBS session is to be provided via the TN, and the second network device 220 may include at least one of a TAI list and a cell ID list into the service area description for transmission to the third network device 230.

[0098] In some embodiments, the received service area of the MBS session may comprises at least one of a civic address, geographic coordinates, a radius of the area, a polygon with points denoted by geographic coordinates, cell identifiers, and TAI(s). The second network device 220 may map the received service area of the MBS session to the transmitted service area description.

[0099] In some embodiments, the second network device 220 may receive a satellite ID from the first network device 210, or derive a satellite ID based on the received service area of the MBS session.

[0100] In some embodiments, the second network device 220 determine based on the identity of the first network device 210 whether the first network device 210 is authorized to request the creation of an MBS session via an NTN. If not, the second network device 220 may send a reply to the first network device indicating the rejection of the request of the creation of the MBS session.

[0101] In some embodiments, the second network device 220 may have configuration on selection of the Option 1 (use mapped cell ID) and Option 2 (use small MBS service area list). This requires knowledge of options at the second network device 220. The second network device 220 has also have configuration on when to use mapped cell ID and when to additionally provide the small MBS service area list. It may always translates or provides the received geographical area(s) or civic address(es) from the first network device 210 to the small MBS service area list and a list of TAI(s) and / or cell ID(s) for every MBS session being created. The configuration at the second network device 220 could be per broadcast session configuration or a general configuration valid for all broadcast sessions. This could also be a geographic area based configuration, i.e., in case the service area provided by the first network device 210 falls under a specific region, it means that the new methods are to be enabled. This configuration can be provided by 0AM (Operations, Administration, and Maintenance).

[0102] As mentioned, the request 205 may include the service area description comprising the small MBS service area list in combination with a related Cell Identifier or TAI. At 207, the third network device 230 may select an AMF based on the related Cell Identifier or TAI within the service area description. At 208, the third network device 230 may send a request to start an MBS session to the selected AMF.

[0103] FIGS. 3 to 6 illustrate examples of process flows of MBS session creation in accordance with some embodiments of the present disclosure. The process flows in FIGS. 3 to 6 are example implementations of the process flow 200 illustrated in FIG. 2. These process flows 300, 400, 500 and 600 are based on the MBS session creation procedure illustrated in 3GPP technical specification (TS) 23.247, Release 18, Clause 7.1.1.2.

[0104] In the process flow 300 of FIG.3, the AF provides at least NTN indication flag to the NEF / MBSF. In particular, at step 8, the AF provides an NTN indication that denotes the MBS session will be delivered over NTN only (or both NTN and TN). If this new indication is not sent, then it implies the MBS session is delivered via TN only.

[0105] At step 9a, based on the information received at step 8, the NEF / MBSF may be configured to use mapped cell ID for NTN instead of usual cells ID (if MBS session is delivered over NTN only), and produce routing TAIs or include usual TAI list / Cell Ids, if MBS session delivered over both NTN and TN. Alternatively, the NEF / MBSF may produce a small MBS service area list in case of NTN only. Alternatively, the NEF / MBSF may provide satellite ID(s) associated with the mapped cell ID(s) related to MBS service area in case of NTN only. This configuration can be given to NEF / MBSF by PCF, 0AM, etc. At step 11, the NEF / MBSF relays the above data to the MB-SMF.

[0106] In the process flow 400 of FIG. 4, the AF provides an indication that the MBS session is meant to be transported over NTN. Alternatively, the AF can provide a ‘Mapped cell ID indication’ and / or a “small area list indication.”

[0107] Due to information received at step 8, at step 11, the NEF / MBSF uses the mapped cell IDs instead of usual cells ID and / or the NEF / MBSF provides a small area list. The NEF / MBSF provides routing TAI(s) along with the mapped cell IDs.

[0108] In the process flow 500 of FIG. 5, at step 8, the AF provides an indication that Option 1 is to be used. This requires knowledge of options at the NEF / AF. At step 9a, due to information received at step 8, the NEF / MBSF uses mapped cell IDs and produces routing TAIs. At step 11, the NEF / MBSF relays the above data to the MB-SMF.

[0109] In the process flow 600 of FIG. 6, at step 8, the AF provides an indication that Option 2 is to be used. This requires knowledge of options at NEF / AF. At step 9a, due to information received at step 8, the NEF / MBSF produces a small Area list. At step 11, the NEF / MBSF relays the above data to the MB-SMF.

[0110] FIG. 7 illustrates a flowchart of an example method 700 implemented at a first network device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 700 will be described from the perspective of the first network device 210 with reference to FIG. 2.

[0111] At block 710, the first network device 210 transmit, to a second network device, a request to create an MBS session comprising a service area of the MBS session and at least one of: an indication that the MBS session is to be provided via an NTN; an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell ID to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote theservice area of the MBS session; a service area description of the MBS session, wherein the service area description includes a small MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID.

[0112] In some embodiments, the indication that MBS session is to be provided via the NTN also indicates that the MBS session is also to be provided via a TN.

[0113] In some embodiments, the first network device 210 may further send an MBS session announcement for the MBS session towards at least one UE, wherein the session announcement comprises at least one of the following: an indication that the MBS session is to be provided via the NTN; an indication that the service area of the MBS session is smaller than a cell level granularity; a service area description of the MBS session, wherein the service area description includes a small MBS service area list; or a service area description of the MBS session, wherein the service area description includes a mapped cell ID.

[0114] In some embodiments, the first network device comprises an AF.

[0115] FIG. 8 illustrates a flowchart of an example method 800 implemented at a second network device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 800 will be described from the perspective of the second network device 220 with reference to FIG. 2.

[0116] At block 810, the second network device 220 receives, from a first network device, a request to create a MBS session that is to be provided via an NTN comprising a service area of the MBS session. At block 820, the second network device 220 transmits, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: a small MBS service area list in combination with a related Cell Identifier or TAI, wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

[0117] In some embodiments, the received request to create an MBS session comprises information on how to determine the service area description comprising at least one of: an indication that the MBS session is to be provided via the NTN; an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBSsession requires a mapped cell ID to denote a service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of the MBS session; a service area description of the MBS session, wherein the service area description includes a small MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID; and wherein the transmitted service area description of the MBS session is determined using the received information information on how to determine the service area description.

[0118] In some embodiments, the second network device 220 may determine based on the identity of the first network device or the received service area of the MBS session that the MBS session is to be is to be provided via the NTN; and based on the determination include in the transmitted service area description at least one of the small MBS service area list in combination with the related Cell Identifier or TAI; or the mapped cell identity.

[0119] In some embodiments, the received service area that includes a mapped cell ID also includes at least one routing TAI for the mapped cell ID; and and wherein the transmitted service area description that includes the mapped cell ID also includes the at least one routing TAI.

[0120] In some embodiments, the received indication that the MBS session is to be provided via a NTN also indicates that the MBS session is to be provided via a terrestrial network (TN), and the second network device 220 may include at least one of a TAI list and a cell ID list, into the service area description for transmission to the third network device.

[0121] In some embodiments, the received service area of the MBS session comprises at least one of a civic address, geographic coordinates, a radius of the area, a polygon with points denoted by geographic coordinates, cell identifiers, and tracking areas identifiers, and wherein the second network device 220 may map the received service area of the MBS session to the transmitted service area description.

[0122] In some embodiments, the second network device may receive a satellite ID from the first network device; and / or derive a satellite ID based on the received service area of the MBS session.

[0123] In some embodiments, the second network device 220 may determine based on the identity of the first network device whether the first network device is authorized to request the creation of an MBS session via an NTN; and if the first network device is not authorized to request the creation of an MBS session via an NTN, send a reply to the first networkdevice indicating the rejection of the request of the creation of the MBS session.

[0124] In some embodiments, the second network device comprises at least one of an NEF or an MBSF.

[0125] FIG. 9 illustrates a flowchart of an example method 900 implemented at a third network device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 900 will be described from the perspective of the third network device 230 with reference to FIG. 2.

[0126] At block 910, the third network device 230 receives, from a second network device, a request to create a MBS session including a service area description comprising a small MBS service area list in combination with a related Cell Identifier or TAI, wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided. At block 920, the third network device 230 selects an AMF based on the related Cell Identifier or TAI within the service area description. At block 930, the third network device 230 sends a request to start an MBS session to the selected AMF.

[0127] In some embodiments, the third network device 230 comprises an MB-SMF.

[0128] In some embodiments, an apparatus capable of performing the method 700 may comprise means for performing the respective steps of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0129] In some embodiments, the apparatus comprises: means for means for transmitting, from a first network device and to a second network device, a request to create a Multicast and Broadcast Services (MBS) session comprising a service area of the MBS session and at least one of: an indication that the MBS session is to be provided via a non-terrestrial network (NTN); an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires an mapped cell identity (ID) to denote the service area of the MBS session; an indication that the MBS session requires a small MBS service area list to denote the service area of the MBS session; a service area description of the MBS session, wherein the service area description includes a small MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID.

[0130] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 700. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0131] In some embodiments, an apparatus capable of performing the method 800 may comprise may comprise means for performing the respective steps of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0132] In some embodiments, the apparatus comprises: means for receiving, from a first network device and at a second device, a request to create a Multicast and Broadcast Services (MBS) session that is to be provided via a non-terrestrial network (NTN) comprising a service area of the MBS session; and means for transmitting, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: a small MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier (TAI), wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

[0133] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 800. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0134] In some embodiments, an apparatus capable of performing the method 900 may comprise may comprise means for performing the respective steps of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0135] In some embodiments, the apparatus comprises: means for receiving, from a second network device and a third network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising a small MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI),wherein the small MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; means for selecting an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and means for sending a request to start an MBS session to the selected AMF.

[0136] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 900. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0137] FIG. 10 illustrates a simplified block diagram of a device 1000 that is suitable for implementing some embodiments of the present disclosure. The device 1000 may be provided to implement a communication device, for example, the network devices, base stations, or the terminal devices. As shown, the device 1000 includes one or more processors 1010, one or more memories 1020 coupled to the processor 1010, and one or more communication modules 1040 coupled to the processor 1010.

[0138] The communication module 1040 is for bidirectional communications. The communication module 1040 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

[0139] The processor 1010 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1000 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0140] The memory 1020 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 1024, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 1022 and other volatile memoriesthat will not last in the power-down duration.

[0141] A computer program 1030 includes computer executable instructions that are executed by the associated processor 1010. The program 1030 may be stored in the ROM 1024. The processor 1010 may perform any suitable actions and processing by loading the program 1030 into the RAM 1022.

[0142] The embodiments of the present disclosure may be implemented by means of the program 1030 so that the device 1000 may perform any process of the disclosure as discussed with reference to FIGS. 7 to 9. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0143] In some embodiments, the program 1030 may be tangibly contained in a computer- readable medium which may be included in the device 1000 (such as in the memory 1020) or other storage devices that are accessible by the device 1000. The device 1000 may load the program 1030 from the computer-readable medium to the RAM 1022 for execution. The computer-readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like.

[0144] FIG. 11 illustrates a block diagram of an example of a computer-readable medium 1100 in accordance with some embodiments of the present disclosure. The computer- readable medium 1100 has the program 1030 stored thereon. It is noted that although the computer-readable medium 1100 is depicted in form of CD or DVD in FIG. 11, the computer-readable medium 1100 may be in any other form suitable for carry or hold the program 1030.

[0145] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0146]

[0147] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or methods 700 to 900 as described above with reference to FIGS. 7 to 9. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0148] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0149] In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer-readable medium, and the like.

[0150] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitablecombination of the foregoing. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0151] Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

[0152] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

WHAT IS CLAIMED IS:

1. A second network device, the second network device comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second network device at least to: receive, from a first network device, a request to create a Multicast and Broadcast Services (MBS) session that is to be provided via a non-terrestrial network (NTN) comprising a service area of the MBS session; and transmit, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: an MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier (TAI), wherein the MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

2. The second network device of claim 1, wherein the received request to create an MBS session comprises information on how to determine the service area description comprising at least one of: an indication that the MBS session is to be provided via the NTN; an indication that the service area of the MBS session is smaller than a cell level granularity; an indication that the MBS session requires a mapped cell identity (ID) to denote a service area of the MBS session; an indication that the MBS session requires an MBS service area list to denote the service area of the MBS session; a service area description of the MBS session, wherein the service area description includes an MBS service area list; a service area description of the MBS session, wherein the service area description includes a mapped cell ID; or a satellite ID;32and wherein the transmitted service area description of the MBS session is determined using the received information information on how to determine the service area description.

3. The second network device of claim 1, wherein the second network device is further caused to: determine based on the identity of the first network device or the received service area of the MBS session that the MBS session is to be is to be provided via the NTN; and based on the determination include in the transmitted service area description at least one of the MBS service area list in combination with the related Cell Identifier or TAI; or the mapped cell identity.

4. The second network device of claims 1, wherein the received service area that includes a mapped cell ID also includes at least one routing TAI for the mapped cell ID; and and wherein the transmitted service area description that includes the mapped cell ID also includes the at least one routing TAI.

5. The second network device of any of claims 1 to 4, wherein the received indication that the MBS session is to be provided via an NTN also indicates that the MBS session is to be provided via a terrestrial network (TN), and the second network device is further caused to: include at least one of a TAI list and a cell ID list, into the service area description for transmission to the third network device.

6. The second network device of any of claims 1 to 5, wherein the received service area of the MBS session comprises at least one of a civic address, geographic coordinates, a radius of the area, a polygon with points denoted by geographic coordinates, cell identifiers, and tracking areas identifiers, and wherein the second network device is further caused to: map the received service area of the MBS session to the transmitted service area description.

337. The second network device of any of claims 1 to 6, wherein the second network device is further caused to at least one of: receive a satellite ID from the first network device; or derive a satellite ID based on the received service area of the MBS session.

8. The second network device of any of claims 1 to 7, wherein the second network device is further caused to: determine based on the identity of the first network device whether the first network device is authorized to request the creation of an MBS session via an NTN; and if the first network device is not authorized to request the creation of an MBS session via an NTN, send a reply to the first network device indicating the rejection of the request of the creation of the MBS session.

9. The second network device of any of claims 1 to 8, wherein the second network device comprises at least one of a Network Exposure Function (NEF) or an MBS Function (MBSF).

10. A third network device, the third network device comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second network device at least to: receive, from a second network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising an MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI), wherein the MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; select an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and send a request to start an MBS session to the selected AMF.

11. The third network device of claim 10, wherein the third network device comprises a Multicast and Broadcast Session Management Function (MB-SMF).

12. A method comprising: receiving, from a first network device and at a second device, a request to create a Multicast and Broadcast Services, MBS, session that is to be provided via a non-terrestrial network, NTN, comprising a service area of the MBS session; and transmitting, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: an MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier, TAI, wherein the MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

13. A method comprising: receiving, from a second network device and a third network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising an MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI), wherein the MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; selecting an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and sending a request to start an MBS session to the selected AMF.

14. An apparatus comprising: means for receiving, from a first network device and at a second device, a request to create a Multicast and Broadcast Services (MBS) session that is to be provided via a nonterrestrial network (NTN) comprising a service area of the MBS session; and means for transmitting, to a third network device, a request to create the MBS session comprising a service area description of the MBS session derived from the received service area of the MBS session, wherein the service area description includes at least one of: an MBS service area list in combination with a related Cell Identifier or Tracking Area Identifier (TAI), wherein the MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; or a mapped cell identity.

15. An apparatus comprising: means for receiving, from a second network device and a third network device, a request to create a Multicast and Broadcast Services (MBS) session including a service area description comprising an MBS service area list in combination with a related Cell Identifier or tracking area identifier (TAI), wherein the MBS service area list denotes the area within the area identified by the Cell Identifier or TAI where the MBS session is to be provided; means for selecting an Access and Mobility Management Function (AMF) based on the related Cell Identifier or TAI within the service area description; and means for sending a request to start an MBS session to the selected AMF.36

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