Service continuity for broadcast services in ntn

Abstract

Methods and systems are described for receiving and providing MBS to UEs. Certain embodiments proposed include the introduction of additional signaling to the existing MBS control information to make a receiving UE aware, well in advance, of the upcoming satellites 5 that provide the same MBS service as the current satellite in the same geographical area. Certain embodiments include new signaling that indicates upcoming satellites which provide the same MBS service as the current satellite, together with the expected time when those satellites start covering the same cell / intended service area.

Description

SERVICE CONTINUITY FOR BROADCAST SERVICES IN NTNCROSS REFERENCE TO RELATED INFORMATION

[0001] This application claims the benefit of United States of America priority application No. 63 / 703,764 filed on October 4, 2024, titled “Service Continuity for Broadcast Services in NTN.”TECHNICAL FIELD

[0002] The present disclosure generally relates to systems and methods for receiving and transmitting a MBS in a NTN-based communication system, and more specifically to continuity of service of said MBS.BACKGROUNDMulticast and Broadcast Services (MBS) in 5G

[0003] As part of Rel-17 and Rel-18, 3GPP (3rdGeneration Partnership Project) introduced the support of multicast / broadcast services (MBS), which offer communication service providers (CSP) the ability to serve one-to-many use cases, such as mission-critical push-to-talk, using 3GPP mobile network infrastructures, in a better way. MBS solutions can offer improved communications efficiency, where a single downlink radio signal can be reached by multiple user equipments (UEs). This can also be referred to as point-to-multipoint (PTM) distribution. The 3GPP standardized functionalities allow for implementation of MBS features with little or no hardware impact on network and UEs. This means that CSPs can utilize the same spectrum band as used for unicast services and support implementations even without dedicated broadcast bands.

[0004] Rel-17 NR MBS specifies both:• a broadcast communication service, in which data is transmitted to all users in a broadcast service area, and• a multicast communication service, in which data is transmitted to a dedicated set of users (i.e., not all users within coverage of the multicast service are authorized to receive the data).

[0005] The broadcast service is received without the UE using the uplink, whichis always possible, as long as the UE is within coverage. To receive multicast, the UE needs to be “connected” and will therefore also need to use the uplink, as with unicast.

[0006] The 5G Core network (5GC) may provide IP (internet protocol) multicast data to UEs over MBS sessions, which are established and released, as per service requirements. An MBS session may be either a multicast session or a broadcast session and has associated Quality of Service (QoS) requirements. In the radio access network (RAN), each MBS session is carried to UEs over one or more MBS Radio Bearers (MRBs), which are set up to provide the needed IP multicast communication within the QoS requirements. These MRBs are the MBS counterpart to the Data Radio Bearers (DRBs) used to carry the unicast data of a PDU (packet data unit) session in the RAN. For MBS broadcast, a broadcast MRB is used. The UE is configured to receive the broadcast MBS session via two broadcast signaling means: system information block (SIB) and the logical channel MBS control channel (MCCH). The user data of the MBS session is transmitted over the logical channel MBS traffic channel (MTCH). To support such signaling needs of MBS broadcast, SIB has been extended in Rel- 17 to provide the configuration for MCCH and basic configurations of MTCH. MCCH provides information about the broadcast MBS sessions that are available and additional configurations to receive the MBS data on MTCH (see Figure 1, which illustrates sequential acquisition and use of SIB, MCCH and MTCH).Service Continuity for MBS Broadcast

[0007] One salient aspect of MBS is the same MBS service can be provided in multiple cells, i.e., and MBS service area may contain multiple cells. As a result, it is important to have MBS delivered to a UE smoothly when the UE moves from one cell to another, a feature often referred to as Service continuity. In 5G systems, service continuity for MBS broadcast for UEs in RRC IDLE (Radio Resource Control Idle) or RRC INACTIVE is ensured through a combination of the following mechanisms:• MCCH indicates a list of neighbour cells providing the same MBS broadcast services as provided in the serving cell.• Information about which frequency is providing which MBS broadcast services via point-to-multipoint (PTM) transmission is obtainable through User Service Description (USD) or through a combination of USD and SIB21. Specifically, SIB21 contains MBS Frequency Selection Area ID (FSAI) which identifies a preconfigured area within, and in proximity to, which the cell(s)announces the FSAI and the associating frequency.

[0008] The first mechanism allows a UE to request unicast reception of the service before moving to a cell not providing the MBS broadcast service(s) using point-to- multipoint (PTM) transmission. The second mechanism helps the UE avoid the need to read MBS broadcast related system information and potentially MCCH on neighbour frequencies. The UE can figure out the TMGI-Frequency (Temporary Mobile Group Identity) mapping from the USD or from the combination of USD and SIB21 and is allowed to make the frequency highest priority in cell reselection.

[0009] A UE in RRC CONNECTED can send MBS Interest Indication (Mil) to the gNB to indicate the UE’s interest in certain MBS broadcast services. The gNB can use the Mil to control the UE to allow the UE to receive the MBS services the UE is interested in.

[0010] The following excerpt from TS 38.300 specifies Service continuity for MBS broadcast.««««««««< Start of excerpt from TS 38.300 V18.2.0 »»»»»»>16.10.6.5 Service Continuity16.10.6.5.0 GeneralMobility principles build on existing functionality including functions described in clause 9.2.NR MBS supports MBS frequency layer prioritization for MBS broadcast sessions. The gNBs may be configured with the MBS FSA ID(s) supported by each of their cells. The gNBs may exchange this information with their neighbours within Xn Setup messages and subsequent Xn Configuration Update messages to help with frequency layer prioritization. The MBS FSA ID is described in TS 23.247

[0045] ,16.10.6.5.1 Service Continuity in RRC IDLE or RRC INACTIVEMobility procedures for MBS reception allow the UE to start or continue receiving MBS service(s) when changing cells. The gNB may indicate in the MCCH the list of neighbour cells providing the same MBS broadcast service(s) as provided in the serving cell. This allows the UE, e.g., to request unicast reception of the service before moving to a cell not providing the MBS broadcast service (s) using PTM transmission. To avoid the need to read MBS broadcast related system information and potentially MCCH on neighbour frequencies, the UE is made aware of which frequency is providing which MBS broadcast services via PTM, through User Service Description, as defined in TS26.517

[0046] , or the combination of the following:User Service Description (USD);SIB21, as defined in clause 7.3.1.NOTE: UE can request unicast reception of the service after moving to a cell not providing the MBS broadcast service(s) using PTM transmission.In RRC IDLE and RRC INACTIVE, the UE applies the normal cell reselection rules with the following modifications: the UE which is receiving or interested to receive MBS broadcast service(s) via PTM and can only receive these MBS broadcast service(s) via PTM while camping on the frequency providing these MBS broadcast service(s) is allowed to make this frequency highest priority when the conditions described in TS 38.304

[0010] are met; when the MBS broadcast service(s) which the UE is interested in are no longer available (after the end of the session) or the UE is no longer interested in receiving the service(s), the UE no longer prioritises the frequency providing these MBS broadcast service(s).16.10.6.5.2 Service Continuity in RRC CONNECTEDTo ensure service continuity of MBS broadcast, the UE in RRC CONNECTED state may send MBS Interest Indication to the gNB, consisting of the following information:List of MBS frequencies UE is receiving or interested to receive, sorted in decreasing order of interest;Priority between the reception of all listed MBS frequencies and the reception of any unicast bearer and multicast MRB;List of MBS broadcast services the UE is receiving or interested to receive, in case SIB 20 is provided for PCell or SCell.MBS Interest Indication information reporting can be implicitly enabled / disabled by the presence of SIB21.The gNB may use this information, together with the information about the UE's capabilities (e.g., supported band combinations), when providing an RRC configuration and / or downlink assignments to the UE or to release DRBs / multicast MRBs, to allow the UE to receive the MBS services the UE is interested in. MBS Interest Indication information can be exchanged between source gNB and target gNB during handover.««««««««< End of excerpt from TS 38.300 V18.2.0»»»»»»>Non-terrestrial Networks (NTN)

[0011] To benefit from the strong mobile ecosystem and economy of scale, the satellite network based on the terrestrial wireless access technologies including LTE (Long Term Evolution) and NR (New Radio) for satellite networks, is being specified in the 3GPP standard.

[0012] In 3GPP Release 15, the first release of the 5G system (5GS) was specified. This is a new generation’s radio access technology intended to serve use cases such as enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC) and massive machine type communication (mMTC). 5G includes the New Radio (NR) access stratum interface and the 5G Core Network (5GC). The NR physical and higher layers are reusing parts of the LTE specification, and additional components are introduced when motivated by the new use cases.

[0013] In Release 15 3GPP also started the work to prepare NR for operation in a Non-Terrestrial Network (NTN). The work was performed within the study item “NR to support Non-Terrestrial Networks” and resulted in TR 38.811. In Release 16 the work to prepare NR for operation in an NTN network continues with the study item “Solutions for NR to support Non-Terrestrial Network”, see TR 38.821. In parallel the interest to adapt LTE for operation in NTN is growing. As a consequence, 3GPP introduced support for NTN in both LTE (TR 36.763) and NR (RP-221806) in Release 17. After the basic functionality was established, NTN enhancements continued in Release 18 for both LTE (RP-220208) and NR (RP-223534).Satellite Communications

[0014] Some aspects of satellite communication include: terminology and components; architecture; beam patterns in satellite communications; and ephemeris data.

[0015] Terminology and components: A few notes on terminology and components. a. A satellite radio access network usually includes the following components: i. A satellite that refers to a space-home platform. ii. An earth-based gateway that connects the satellite to a base station or a core network, depending on the choice of architecture. iii. Feeder link that refers to the link between a gateway and a satelliteiv. Access link that refers to the link between a satellite and a UE. b. A satellite network or satellite based mobile network may also be called as nonterrestrial network (NTN). On the other hand, mobile network with base stations on the group may also be called as terrestrial network (TN) or non-NTN network. A satellite within NTN may be called as NTN node, NTN satellite or simply a satellite. c. Depending on the orbit altitude, a satellite may be categorized as low earth orbit (LEO), medium earth orbit (MEO), or geostationary earth orbit (GEO) satellite. i. LEO: typical heights ranging from 250 - 1,500 km, with orbital periods ranging from 90 - 120 minutes. ii. MEO: typical heights ranging from 5,000 - 25,000 km, with orbital periods ranging from 3 - 15 hours. iii. GEO: height at about 35,786 km, with an orbital period of 24 hours. d. The significant orbit height means that satellite systems are characterized by a path loss that is significantly higher than what is expected in terrestrial networks. To overcome the pathloss it is often required that the access and feeder links are operated in line-of-sight conditions, and that the UE is equipped with an antenna offering high beam directivity.

[0016] Architecture: A few notes on architecture. a. Two basic architectures can be distinguished for satellite communication networks, depending on the functionality of the satellites in the system: i. Transparent payload (also referred to as bent pipe architecture). The satellite forwards the received signal between the terminal and the network equipment on the ground with only amplification and a shift from uplink frequency to downlink frequency. When applied to general 3 GPP architecture and terminology, the transparent pay load architecture means that the gNB is located on the ground and the satellite forwards signals / data between the gNB and the UE ii. Regenerative payload. The satellite includes on-board processing to demodulate and decode the received signal and regenerate the signal before sending it back to the earth. When applied to general 3 GPP architecture and terminology, the regenerative payload architecture means that the gNB is located in the satellite. b. In the work item for NR NTN and loT NTN in 3GPP Release 17 and Release18, only the transparent payload architecture is considered (see, e.g., TR 36.763; RP-221806; RP -220208; RP-223534). Figure 2 shows an example architecture of a satellite network 200 with bent pipe transponders (i.e., the transparent payload architecture). The gNB (g node B) may be integrated in the gateway or connected to the gateway via a terrestrial connection (wire, optic fiber, wireless link).

[0017] Beam Patterns in Satellite Communications: A few notes on beam patterns. a. A communication satellite typically generates several beams over a given area. The footprint of a beam is usually in an elliptic shape, which has been traditionally considered as a cell. The footprint of a beam is also often referred to as a spotbeam. The spotbeam may move over the earth surface with the satellite movement or may be earth fixed with some beam pointing mechanism used by the satellite to compensate for its motion. The size of a spotbeam depends on the system design, which may range from tens of kilometers to a few thousands of kilometers. Figure 3 shows an example architecture of a satellite network 300 with bent pipe transponders. b. The NTN beam may in comparison to the beams observed in a terrestrial network be very wide and cover an area outside of the area defined by the served cell. Beam covering adjacent cells will overlap and cause significant levels of intercell interference. To overcome the large levels of interference a typical approach is an NTN to configure different cells with different carrier frequencies and polarization modes.

[0018] Ephemeris Data: A few notes on ephemeris data. a. In TR 38.821, it has been captured that ephemeris data should be provided to the UE, for example to assist with pointing a directional antenna (or an antenna beam) towards the satellite. A UE knowing its own position, e.g., thanks to GNSS (Global Navigation Satellite System) support, may also use the ephemeris data to calculate correct Timing Advance (TA) and Doppler shift. The contents of the ephemeris data and the procedures on how to provide and update such data have not yet been studied in detail. b. A satellite orbit can be fully described using 6 parameters. Exactly which set of parameters is used can be decided by the user; many different representations are possible. For example, a choice of parameters used often in astronomy is theset (a, e, i, Q. co, t). Here, the semi-major axis and the eccentricity e describe the shape and size of the orbit ellipse; the inclination i, the right ascension of the ascending node Q. and the argument of periapsis co determine its position in space, and the epoch t determines a reference time (e.g. the time when the satellites moves through periapsis). The set of these parameters is illustrated in Figure 4. c. A two-line element set (TLE) is a data format encoding a list of orbital elements of an Earth-orbiting object for a given point in time, the epoch. As an example of a different parametrization, TLEs use mean motion n and mean anomaly M instead of a and t. d. A completely different set of parameters is the position and velocity vector (x, y, z, vx, vy, vz) of a satellite. These are sometimes called orbital state vectors. They can be derived from the orbital elements and vice versa since the information they contain is equivalent. All these formulations (and many others) are possible choices for the format of ephemeris data to be used in NTN. e. It is important that a UE can determine the position of a satellite with accuracy of at least a few meters. However, several studies have shown that this might be hard to achieve when using the de-facto standard of TLEs. On the other hand, LEO satellites often have GNSS receivers and can determine their position with some meter level accuracy. f. Another aspect discussed during the study item and captured in TR 38.821, is the validity time of ephemeris data. Predictions of satellite positions in general degrade with increasing age of the ephemeris data used, due to atmospheric drag, maneuvering of the satellite, imperfections in the orbital models used, etc. Therefore, the publicly available TLE data are updated quite frequently, for example. The update frequency depends on the satellite and its orbit and ranges from weekly to multiple times a day for satellites on very low orbits which are exposed to strong atmospheric drag and need to perform correctional maneuvers often. So, while it seems possible to provide the satellite position with the required accuracy, care needs to be taken to meet these requirements, e.g., when choosing the ephemeris data format, or the orbital model to be used for the orbital propagation. g. Ephemeris data consists of at least 5 parameters describing the shape and position in space of the satellite orbit. It also comes with a timestamp, which isthe time when the other parameters describing the orbit ellipse were obtained. The position of the satellite at any given time in the nearer future can be predicted from this data using orbital mechanics. The accuracy of this prediction will however degrade as one projects further and further into the future. The validity time of a certain set of parameters depends on many factors like the type and altitude of the orbit, but also the desired accuracy, and ranges from the scale of a few days to a few years.Release 19 NTN Enhancements

[0019] The standardization of NTN technologies continues in 3GPP with another two work items for NR and LTE, respectively (see, e.g. RP-234077; RP-234078). The justification for these enhancements is the necessities of the commercial deployments that are ongoing at the moment of writing. Based on real deployment or deployment plans, further evolution of NR and loT (internet of things) NTN is required.

[0020] One of the objectives of the work on release 19 of the 3 GPP standard is to specify SIB signaling to indicate the intended service area of a broadcast service (e.g., MBS broadcast) via NR NTN, especially in case the satellite footprint covers a larger area. So far, RAN2 has agreed to consider at least the case where the indicated intended service area covers a portion of a NTN cell and that the intended service area can cover the area of more than one NTN cells (or portions thereof).Satellite Background

[0021] Starting in Release 15, 3 GPP began studying support for non-terrestrial networks (NTN). Normative work was introduced in Release 17 which comprised a radio frequency processing function (transceiver) on a satellite platform interconnected with a terrestrial base station, also known as transparent architecture, where the NTN payload is passed transparently, no unpacking. In Release 19 regenerative architecture may be supported, where part or all of the gNB can be in the satellite. Figure 5 illustrates a basic NTN architecture. Figure 6 illustrates different NTN Architecture Types.

[0022] Although the Transparent Architecture is the one most used in deployments today, the semi-transparent architecture, where the RU is on-board the satellite, shows some promise of providing improved network scalability and performance. An NTN base station system is also known as a Satellite Access Node (SAN) in 3GPP. In 3GPP Release 18 the SAN is depicted with the NTN payload RF as comprising 3 logical functions. Figure 7illustrates the SAN NTN payload RF functions.

[0023] 3GPP standards work is focused on providing support to adapted UEs (i.e., UEs which support NTN). Solutions which enable support for pre-existing handsets might not be the focus in 3GPP specs (i.e. no eNB / gNB only solutions) but should also be covered by any claims, where applicable. Implementation specific solutions are of interest. The current ORAN (Open RAN) considerations are also relevant for NTN. For example, in Release 17 transparent architecture point 7 below is on satellite and the rest are terrestrial based. In regenerative architecture any of these points could be on satellite: a. O-CU: O-RAN Central Unit: a logical node hosting RRC, SDAP (Service Data Adaptation Protocol) and PDCP (Packet Data Convergence Protocol) protocols b. O-CU-CP: O-RAN Central Unit - Control Plane: a logical node hosting the RRC and the control plane part of the PDCP protocol c. O-CU-UP: O-RAN Central Unit - User Plane: a logical node hosting the user plane part of the PDCP protocol and the SDAP protocol d. O-DU: O-RAN Distributed Unit: a logical node hosting RLC (Radio Link Control) / MAC (Medium Access Control) / High-PHY (high physical layer) layers based on a lower layer functional split. e. O-RU: O-RAN Radio Unit: a logical node hosting Low-PHY layer and RF (radio frequency) processing based on a lower layer functional split. This is similar to 3GPP’s “TRP” (transmission reception point) or “RRH” (remote radio head) but more specific in including the Low-PHY layer (FFT (Fast Fourier Transform) / iFFT (inverse FFT), PRACH (Physical Random Access Channel) extraction).

[0024] Certain ORAN architecture terms are derived from 3 GPP architecture terms. For example, the O-RU and O-DU are analogous to a 3GPP DU and the O-CU and near RT-RIC are analogous to a 3 GPP CU. Figure 8 graphically depicts the correspondence of terms and basic ORAN architecture and 3 GPP terminology.SUMMARY

[0025] One embodiment under the present disclosure comprises a method performed by a UE for receiving a MBS in a NTN-based communication system. The method includes: receiving an indication for service continuity between one or more current servingcells providing the MBS and a future NTN cell / footprint provided by a non-geostationary orbiting satellite.

[0026] Another possible method embodiment under the present disclosure is a method performed by a network node for indicating upcoming satellites to a UE. The method comprises transmitting an indication that informs the UE which upcoming satellites provide the same MBS services as a current satellite in the same geographical area.

[0027] Another embodiment under the present disclosure is a UE for receiving a MBS in a NTN-based communication system. The UE includes: processing circuitry; and a memory. The memory stores instructions whereby the processing circuitry is operable to perform the steps of: receiving an indication for service continuity between one or more current serving cells providing the MBS and a future NTN cell / footprint provided by a non- geostationary orbiting satellite.

[0028] Another embodiment under the present disclosure is a network node for indicating upcoming satellites to a UE. The network node includes: processing circuitry; and a memory. The memory stores instructions whereby the processing circuitry is operable to perform the steps of: transmitting an indication that informs the UE which upcoming satellites provide the same MBS services as a current satellite in the same geographical area.

[0029] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an indication of the scope of the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0030] For a more complete understanding of the present disclosure, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0031] Fig. 1 illustrates sequential acquisition and use of SIB, MCCH, and MTCH;

[0032] Fig. 2 illustrates an example of bent pipe architecture;

[0033] Fig. 3 illustrates an example of bent pipe architecture;

[0034] Fig. 4 illustrates orbital elements;

[0035] Fig. 5 illustrates basic NTN architecture;

[0036] Fig. 6 illustrates NTN architecture types;

[0037] Fig. 7 illustrates SAN NTN payload RF functions;

[0038] Fig. 8 illustrates basic ORAN architecture;

[0039] Fig. 9 illustrates a MBSBroadcastConfiguration IE;

[0040] Fig. 10 illustrates an example of an SSA definition;

[0041] Fig. 11 illustrates an example of a MBSBroadcastConfiguration IE;

[0042] Fig. 12 illustrates an example of a MBSBroadcastConfiguration IE;

[0043] Fig. 13 illustrates an example of a MBS-NeighbourCellList IE;

[0044] Fig. 14 illustrates a possible method embodiment under the present disclosure;

[0045] Fig. 15 illustrates a possible method embodiment under the present disclosure;

[0046] Fig. 16 shows a schematic of a communication system embodiment under the present disclosure;

[0047] Fig. 17 shows a schematic of a user equipment embodiment under the present disclosure;

[0048] Fig. 18 shows a schematic of a network node embodiment under the present disclosure;

[0049] Fig. 19 shows a schematic of a virtualization environment embodiment under the present disclosure.DETAILED DESCRIPTION

[0050] Before describing various embodiments of the present disclosure in detail, it is to be understood that this disclosure is not limited to the parameters of the particularly exemplified systems, methods, apparatus, products, processes, and / or kits, which may, of course, vary. Thus, while certain embodiments of the present disclosure will be described in detail, with reference to specific configurations, parameters, components, elements, etc., the descriptions are illustrative and are not to be construed as limiting the scope of the claimed embodiments. In addition, the terminology used herein is for the purpose of describing the embodiments and is not necessarily intended to limit the scope of the claimed embodiments. Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0051] A few notes on terminology. In this present description, the term NonTerrestrial Network (NTN) may, depending on the context, refer to either or both of NR NTN and loT NTN, and sometimes the term is used to refer to only loT NTN. The embodiments outlined below are described mainly in terms of LTE based NTNs, but they are equally applicable in an NTN based on NR technology. The term “network” is used in the solution description to refer to a network node, which typically will be a gNB (e.g. in a NR based NTN) or an eNB (e.g. in an LTE based NTN, such as an loT NTN), but which may also be a base station or an access point in another type of network based on communication via satellites or HAPS, or any other network node (in a network involving satellites or HAPS) with the ability to directly or indirectly communicate with a UE. In this section, the term “UE” is used to implicitly refer to a UE interested in MBS Broadcast service. The term MBS configuration is used freely in the present description to refers to the MBS content (sessions) provided in the serving cell. Nonetheless, the term can also include other relevant configuration parameters such as the scheduling, modification period, SSB (synchronization signal block) mapping window, MTCH configuration, etc.

[0052] As described above, there currently exist certain challenges. As described above, for RRC IDLE and RRC INACTIVE UEs, there are two service continuity mechanisms for MBS broadcast in legacy 5GNR systems: the list of neighbor cells providing the same MBS service (contained in MCCH) and the mapping between an MBS service and certain frequencies (contained in the USD or by a combination of USD and the FSAI in SIB21).

[0053] While the above mechanisms can be readily applied to provide service continuity for broadcast services in NTN, there are potential issues of such an approach. In particular, for NGSO (non-geostationary orbit) satellites (e.g., LEO), each satellite is expected to provide coverage to a geographical location for a short period of time in the order of a few minutes. Some challenges and aspects include: a. Frequent change of serving cell: A new satellite typically implies a new serving cell and requires the UE to perform mobility procedures (e.g., cell reselection). b. Short transition time: Despite satellite movements are deterministic, the incoming satellite / cell will not be available until a short time (e.g., few seconds) before the existing satellite / cell stops serving the area.

[0054] Updates to System Information broadcast and MCCH configuration are bound to modification periods and are not expected to have such dynamicity. Consequently, the existing service continuity mechanisms may not be suitable for this common NTN scenario when frequent changes and a short transition time caused by satellite movements. For example,even if the network is able to tune the MCCH modification period accordingly, a UE in RRC IDLE / RRC INACTIVE interested in an MBS broadcast service would need to frequently decode the MCCH to acquire an updated list of neighbor cells providing the same broadcast services which contain the target / incoming / replacing cell information. However, it has little time to do so since the UE needs time to acquire SIB1 and SIB20 of a cell before it can decode MCCH, see the description above. Overall, this leads to increased complexity and power consumption for both the UE and network.

[0055] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Leveraging the determinism of satellite movements, certain embodiments proposed in this disclosure include the introduction of additional signaling to the existing MBS control information to make a receiving UE aware, well in advance, of the upcoming satellites that provide the same MBS service as the current satellite in the same or current geographical area (the serving geographical area). Certain embodiments include new signaling that indicates upcoming satellites which provide the same MBS service as the current satellite, together with the expected time when those satellites start covering the same cell / intended service area.

[0056] Certain embodiments may provide one or more of the following technical advantages. The proposed solution helps achieve service continuity for MBS broadcast in NTN. In addition, the teachings of certain embodiments may improve the date rate, latency, and / or power consumption of described UEs and / or components.

[0057] Non-limiting examples of embodiments and / or features under the present disclosure include: satellite-specific solutions; satellite list associated with an area identifier; cell-specific solution; UE behaviours; signaling aspects; Earth moving cells deployments.Satellite-Specific Solution

[0058] In certain embodiments, a new indication is included in the MBS control information that informs the UEs which satellites provide the same MBS services as the serving cell. This information is complemented with the satellite assistance information provided in other System Information blocks (e.g., SIB19).

[0059] The indication may be also composed of the following types of information: a. Satellite service start time: The time instant when a satellite in the list starts serving the current cell or the service area or the intended service area associatedwith the MBS service. For example, a t-service parameter indicating when a certain satellite starts serving the same cell or service area as the current satellite / cell. b. Satellite ID: unique identifier for a satellite within a non-terrestrial network. c. Carrier frequency or PCI (physical cell identity). d. Validity duration: Information about the satellite trajectory, e.g., in the form of at least one of: satellite ephemeris, a reference time, a validity time that indicates the time duration during which the satellite trajectory information is valid. e. Figure 9 illustrates an example of how this new indication can be included in the MBSBroadcastConfiguration IE 900 provided in MCCH for MBS NTN (using the IE (information element) definition from 3GPP TS 38.331 version 18.3.0 as the baseline). For illustrative purposes, this example relates only to the indication using a single bit (other representations could also be used).Satellite List Associated with an Area Identifier

[0060] In a different embodiment, the previous satellite list can be associated with a geographic area, denominated hereon as Satellite Selection Area (SSA). The UE can be informed of the list of satellites that belong to the SSA and may also be provided with the geographical coordinates of the SSA. The UE can receive this information via Service Announcement (e.g., OTT means) or system information broadcast via its serving cell for both the serving cell and current and future neighbor cells. As long as any current or future neighbor cells share, or any upcoming satellites, belong to the same SSA, the UE can expect the provided MBS broadcast services and / or MBS broadcast configuration (e.g., scheduling) to not differ from that of the serving cell’s.

[0061] In an alternative, the SSA is associated with a unique identifier (e.g., represented with an INTEGER ASN.l parameter). In this case, the UE is not informed of the SSA geographic coordinates, nor the complete list of satellites in the SSA, but it is provided with the SSA’s identifier via the serving cell. As long as neighbor cells share the same SSA identifier, the UE can expect the provided MBS broadcast services and / or MBS broadcast configuration (e.g., scheduling) to not to differ from the serving cell’s.

[0062] Figure 10 illustrates an example of how the SSA (SSA definition 1000) can be defined and be associated with a list of satellites, current and future neighbor cells, and the SSA identifier. Figure 11 illustrates an example of how the SSA identifier can be included for the serving cell in a MBSBroadcastConfiguration IE 1100 embodiment provided in MCCHfor MBS NTN (using the IE definition from 3GPP TS 38.331 version 18.3.0 as the baseline).Cell-Specific Solution

[0063] In certain embodiments, a new indication is included in the MBS control information that informs the UEs that the same MBS configuration as the one used in the serving cell applies to the new cell served by the incoming satellite. This indication only considers the very next incoming satellite / cell, which substitutes the serving cell due to the satellite movements (e.g., after the time denoted by t-service in SIB19). In contrast with the previous section, this indication pertains the whole NTN cell covering a certain geographic area (e.g., (quasi)-Earth fixed cells).

[0064] Figure 12 illustrates an example of how this new indication can be included in a MBSBroadcastConfiguration IE 1200 embodiment provided in MCCH for MBS NTN (using the IE definition from 3GPP TS 38.331 version 18.3.0 as the baseline). For illustrative purposes, this example relates only to the indication using a single bit (other representations could also be used).UE Behaviors

[0065] In certain UE-related embodiments under the present disclosure, upon receiving the indication described in previous section in any of the described forms, for the cells or satellites included in the indication, the UE can assume that the target neighbor cell (i.e., served by one of the listed satellites in the indication) of a mobility procedure (e.g., cell reselection) provides the same MBS broadcast services and it can avoid read MBS broadcast related system information (e.g., SIB20) and MCCH configuration.

[0066] In one embodiment, a UE can be configured or preconfigured to skip acquiring the list of neighbor satellites / cells providing the same MBS service if at least one of the following conditions is fulfilled: a. The UE has acquired such a list in the last T seconds (where T can be predefined in specifications or pre-configured in the UE (e.g., in a SIM card) or configurable by the network). b. The list contains at least N satellites or cells (N is a pre-defined or (pre- )configurable parameter). This corresponds to the case when the list contains a significant number of future satellites that can assure the UE to maintain the same MBS service for a certain period of time.

[0067] Embodiments, such as those described above, can take advantage of various signaling embodiments. For example, the list of satellites providing the same MBS service in the previous embodiments described above can be signaled in e.g.,: a system information block (SIB); a MCCH; a MAC CE (control element); or in dedicated RRC signaling (e.g., in a RRCReconfiguration message). Similar means can be used for signaling parameters T and N in various embodiments under the present disclosure.Earth Moving Cells Deployments

[0068] Certain embodiments of the present disclosure are tailored for the scenario of NTN serving (quasi)-Earth fixed cells, where the cell switch entails a change of serving satellite. However, an NTN deployment using Earth moving cells is similarly possible. In this case, it is feasible that the UE performs a mobility procedure (e.g., cell reselection) to a different cell provided by the same satellite. Therefore, indication can adopt a simplified format similar to the one presented above regarding e.g., Cell-Specific Solutions. Note that the SSA concept is equally applicable to this scenario.

[0069] Figure 13 illustrates an example of how this new indication can be included in a MBS-NeighbourCellList IE 1300 embodiment provided in the MBSBroadcastConfiguration IE for MBS NTN (using the IE definition from 3GPP TS 38.331 version 18.3.0 as the baseline). The example extends the existing list and provides the service continuity indication per neighbor cell. For illustrative purposes, this example relates only to the indication using a single bit (other representations could also be used).Additional Embodiments

[0070] Another possible method embodiment under the present disclosure is shown in Figure 14. Method 2200 comprises a method performed by a UE for receiving a MBS in a NTN-based communication system. Step 2210 is receiving an indication for service continuity between one or more current serving cells providing the MBS and a future NTN cell / footprint provided by a non-geostationary orbiting satellite. Method 2200 can comprise a variety of additional, alternative, and / or optional steps. For example, in some variations, the indication is included in MBS control information. In some variations, the indication comprises a MBSBroadcastConfiguration IE. In some embodiments, the indication informs the UE that a MBS configuration of the one or more current serving cells applies to the future NTN cell / footprint. In some embodiments, the indication informs the UE which upcoming satellitesprovide the MBS services comprising the MBS configuration according to the current serving satellite in the current geographical area. In some variations, the indication is complemented with one or more satellite assistance information provided in one or more SIBs. In some embodiments, the indication comprises at least one of: a satellite service start time; a satellite identifier; a carrier frequency; a physical cell identity, PCI; a validity duration; a satellite ephemeris; a reference time; a validity timer; a message from a network node; a message from a satellite. In some embodiments, the indication only considers a very next incoming satellite or cell to substitute for the one or more current serving cells. Some embodiments can further comprise assuming, by the UE, that a target neighbor cell of a mobility procedure provides the same MBS broadcast services as the one or more current serving cells; and based on the assuming, avoiding reading one or more MBS broadcast related system information and one or more MCCH configurations. Some embodiments can further comprise skipping system information acquisition based on the received indication. Some embodiments can further comprise performing a mobility procedure to a different cell provided by a serving satellite or a different satellite. In some embodiments, the future NTN cell / footprint is associated with a SS A, wherein the indication identifies at least one of; one or more satellites associated with the SSA; and / or one or more geographical coordinates associated with the SSA. In some variations, any cell associated with the SSA has the same one or more MTCH configuration parameters as the one or more current serving cells. In some embodiments, the indication is received via at least one of: MBS control information; Non-access Stratum, NAS; a Service announcement. In some variations, the SSA is associated with a unique identifier. In some embodiments, the UE is provided with an identifier of the SSA via a serving cell. Some embodiments can further comprise acquiring a list of any of the one or more satellites that provide the same MBS services as the one or more current serving cells. In some variations, the UE is configured to skip acquiring a list of any of the one or more satellites that provide the same MBS services as the one or more current serving cells, if at least one of the following conditions is fulfilled: the UE has acquired such a list in the last T seconds, wherein T can be at least one of; pre-defined in specifications, pre-configured in the UE, or configurable by a network; or the list contains at least N satellites or cells, wherein N can be at least one of; pre-defined in specifications, preconfigured in the UE, or configurable by a network. In some embodiments, the list is received via at least one of: a SIB; a MCCH; a MAC CE; dedicated RRC signaling. Some embodiments can further comprise performing a mobility procedure to a different cell provided by a serving satellite or a different satellite.

[0071] Another possible method embodiment under the present disclosure is shown in Figure 15. Method 2600 comprises a method performed by a network node for indicating upcoming satellites to a UE. Step 2610 is transmitting an indication that informs the UE which upcoming satellites provide the same MBS services as a current satellite in the same geographical area. Method 2600 can comprise a variety of additional, alternative, and / or optional steps. For example, in some variations, the indication is included in an at least one of: an IE; MBS control information. In some variations, the IE comprises a MBSBroadcastConfiguration IE. In some embodiments, the indication informs the UE that a MBS configuration of the one or more current serving cells applies to the future NTN cell / footprint. In some embodiments, the indication comprises at least one of: a satellite service start time; a satellite identifier; a carrier frequency; a PCI; a validity duration; a satellite ephemeris; a reference time; a validity timer; a message from a network node; a message from a satellite. In some variations, the network node comprises a satellite-based access node of a non-terrestrial network, NTN. In some embodiments, the indication is for service continuity between one or more current serving cells providing MBS and a SSA, and the indication identifies at least one of; one or more satellites associated with the SSA; and / or one or more geographical coordinates associated with the SSA. In some embodiments, the indication is transmitted via at least one of: MBS control information; NAS; a Service Announcement. In some embodiments, any cell associated with the SSA has the same one or more MTCH configuration parameters as the one or more current serving cells. In some variations, the SSA is associated with a unique identifier. In some embodiments, the UE is provided with an identifier of the SSA via a serving cell.

[0072] Figure 16 shows an example of a communication system 3100 in accordance with some embodiments. In the example, the communication system 3100 includes a telecommunication network 3102 that includes an access network 3104, such as a radio access network (RAN), and a core network 3106, which includes one or more core network nodes 3108. The access network 3104 includes one or more access network nodes, such as network nodes 3110a and 3110b (one or more of which may be generally referred to as network nodes 3110), or any other similar 3rd Generation Partnership Project (3GPP) access nodes or non- 3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 3102 includes one or more Open-RAN (ORAN)network nodes. An ORAN network node is a node in the telecommunication network 3102 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 3102, including one or more network nodes 3110 and / or core network nodes 3108.

[0073] Examples of an ORAN network node include an open radio unit ORU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or anon-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies. The network nodes 3110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 3112a, 3112b, 3112c, and 3112d (one or more of which may be generally referred to as UEs 3112) to the core network 3106 over one or more wireless connections.

[0074] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 3100 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 3100 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0075] The UEs 3112 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 3110 and other communication devices. Similarly, the network nodes3110 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 3112 and / or with other network nodes or equipment in the telecommunication network 3102 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 3102.

[0076] In the depicted example, the core network 3106 connects the network nodes 3110 to one or more host computing systems, such as host 3116. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 3106 includes one more core network nodes (e.g., core network node 3108) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 3108. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0077] The host 3116 may be under the ownership or control of a service provider other than an operator or provider of the access network 3104 and / or the telecommunication network 3102. The host 3116 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0078] As a whole, the communication system 3100 of Figure 16 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or anyother appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0079] In some examples, the telecommunication network 3102 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 3102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 3102. For example, the telecommunications network 3102 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0080] In some examples, the UEs 3112 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 3104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 3104. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi -radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN- DC).

[0081] In the example, the hub 3114 communicates with the access network 3104 to facilitate indirect communication between one or more UEs (e.g., UE 3112c and / or 3112d) and network nodes (e.g., network node 3110b). In some examples, the hub 3114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 3114 may be a broadband router enabling access to the core network 3106 for the UEs. As another example, the hub 3114 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 3110, or by executable code, script, process, or other instructions in the hub 3114. As another example, the hub 3114 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 3114 may be a content source. For example, for a UE that is a VR device, display, loudspeaker, or other media delivery device, the hub 3114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 3114then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 3114 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0082] The hub 3114 may have a constant / persistent or intermittent connection to the network node 3110b. The hub 3114 may also allow for a different communication scheme and / or schedule between the hub 3114 and UEs (e.g., UE 3112c and / or 3112d), and between the hub 3114 and the core network 3106. In other examples, the hub 3114 is connected to the core network 3106 and / or one or more UEs via a wired connection. Moreover, the hub 3114 may be configured to connect to an M2M service provider over the access network 3104 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 3110 while still connected via the hub 3114 via a wired or wireless connection. In some embodiments, the hub 3114 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 3110b. In other embodiments, the hub 3114 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 3110b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0083] Figure 17 shows a UE 3200 in accordance with some embodiments. The UE 3200 presents additional details of some embodiments of the UE 3112 of Figure 16. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage / playback device, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptopmounted equipment (LME), an Augmented Reality (AR) or Virtual Reality (VR) device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0084] A UE may support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle- to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense ofa human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0085] The UE 3200 includes processing circuitry 3202 that is operatively coupled via a bus 3204 to an input / output interface 3206, a power source 3208, a memory 3210, a communication interface 3212, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 17. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0086] The processing circuitry 3202 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 3210. The processing circuitry 3202 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 3202 may include multiple central processing units (CPUs).

[0087] In the example, the input / output interface 3206 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 3200. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc.,or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0088] In some embodiments, the power source 3208 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 3208 may further include power circuitry for delivering power from the power source 3208 itself, and / or an external power source, to the various parts of the UE 3200 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 3208. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 3208 to make the power suitable for the respective components of the UE 3200 to which power is supplied.

[0089] The memory 3210 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 3210 includes one or more application programs 3214, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 3216. The memory 3210 may store, for use by the UE 3200, any of a variety of various operating systems or combinations of operating systems.

[0090] The memory 3210 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external microDIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 3210 may allow the UE 3200 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing acommunication system may be tangibly embodied as or in the memory 3210, which may be or comprise a device-readable storage medium.

[0091] The processing circuitry 3202 may be configured to communicate with an access network or other network using the communication interface 3212. The communication interface 3212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 3222. The communication interface 3212 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 3218 and / or a receiver 3220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 3218 and receiver 3220 may be coupled to one or more antennas (e.g., antenna 3222) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0092] In the illustrated embodiment, communication functions of the communication interface 3212 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / intemet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0093] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 3212, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0094] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0095] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 3200 shown in Figure 17.

[0096] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3 GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0097] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, thefirst UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0098] Figure 18 shows a network node 3300 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)), O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0099] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).[000100] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi- cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).[000101] The network node 3300 includes a processing circuitry 3302, a memory 3304, a communication interface 3306, and a power source 3308. The network node 3300 may be composed of multiple physically separate components (e.g., aNodeB component and aRNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 3300 comprisesmultiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 3300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 3304 for different RATs) and some components may be reused (e.g., a same antenna 3310 may be shared by different RATs). The network node 3300 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 3300, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 3300.[000102] The processing circuitry 3302 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 3300 components, such as the memory 3304, to provide network node 3300 functionality.[000103] In some embodiments, the processing circuitry 3302 includes a system on a chip (SOC). In some embodiments, the processing circuitry 3302 includes one or more of radio frequency (RF) transceiver circuitry 3312 and baseband processing circuitry 3314. In some embodiments, the radio frequency (RF) transceiver circuitry 3312 and the baseband processing circuitry 3314 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 3312 and baseband processing circuitry 3314 may be on the same chip or set of chips, boards, or units.[000104] The memory 3304 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that maybe used by the processing circuitry 3302. The memory 3304 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 3302 and utilized by the network node 3300. The memory 3304 may be used to store any calculations made by the processing circuitry 3302 and / or any data received via the communication interface 3306. In some embodiments, the processing circuitry 3302 and memory 3304 is integrated.[000105] The communication interface 3306 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 3306 comprises port(s) / terminal(s) 3316 to send and receive data, for example to and from a network over a wired connection. The communication interface 3306 also includes radio front-end circuitry 3318 that may be coupled to, or in certain embodiments a part of, the antenna 3310. Radio front-end circuitry 3318 comprises filters 3320 and amplifiers 3322. The radio front-end circuitry 3318 may be connected to an antenna 3310 and processing circuitry 3302. The radio front-end circuitry may be configured to condition signals communicated between antenna 3310 and processing circuitry 3302. The radio front-end circuitry 3318 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 3318 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 3320 and / or amplifiers 3322. The radio signal may then be transmitted via the antenna 3310. Similarly, when receiving data, the antenna 3310 may collect radio signals which are then converted into digital data by the radio front-end circuitry 3318. The digital data may be passed to the processing circuitry 3302. In other embodiments, the communication interface may comprise different components and / or different combinations of components.[000106] In certain alternative embodiments, the network node 3300 does not include separate radio front-end circuitry 3318, instead, the processing circuitry 3302 includes radio front-end circuitry and is connected to the antenna 3310. Similarly, in some embodiments, all or some of the RF transceiver circuitry 3312 is part of the communication interface 3306. In still other embodiments, the communication interface 3306 includes one or more ports or terminals 3316, the radio front-end circuitry 3318, and the RF transceiver circuitry 3312, as part of a radio unit (not shown), and the communication interface 3306 communicates with the baseband processing circuitry 3314, which is part of a digital unit (not shown).[000107] The antenna 3310 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 3310 may be coupled to the radio front-end circuitry 3318 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 3310 is separate from the network node 3300 and connectable to the network node 3300 through an interface or port.[000108] The antenna3310, communication interface 3306, and / orthe processing circuitry 3302 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 3310, the communication interface 3306, and / or the processing circuitry 3302 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.[000109] The power source 3308 provides power to the various components of network node 3300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 3308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 3300 with power for performing the functionality described herein. For example, the network node 3300 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 3308. As a further example, the power source 3308 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.[000110] Embodiments of the network node 3300 may include additional components beyond those shown in Figure 18 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 3300 may include user interface equipment to allow input of information into the network node 3300 and to allow output of information from the network node 3300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 3300. In some embodiments providing a core network node, such as corenetwork node 3108 of Figure 16 some components, such as the radio front-end circuitry 3318 and the RF transceiver circuitry 3312 may be omitted.[000111] Figure 19 is a block diagram illustrating a virtualization environment 3400 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 3400 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 3400 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface. Virtualization may facilitate distributed implementations of a network node, UE, core network node, or host.[000112] Applications 3402 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 3400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.[000113] Hardware 3404 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 3406 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 3408a and 3408b (one or more of which may be generally referred to as VMs 3408), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 3406 may present a virtual operating platform that appears like networking hardware to the VMs 3408.[000114] The VMs 3408 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 3406. Different embodiments of the instance of a virtual appliance 3402 may beimplemented on one or more of VMs 3408, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.[000115] In the context of NFV, a VM 3408 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, nonvirtualized machine. Each of the VMs 3408, and that part of hardware 3404 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 3408 on top of the hardware 3404 and corresponds to the application 3402.[000116] Hardware 3404 may be implemented in a standalone network node with generic or specific components. Hardware 3404 may implement some functions via virtualization. Alternatively, hardware 3404 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 3410, which, among others, oversees lifecycle management of applications 3402. In some embodiments, hardware 3404 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 3412 which may alternatively be used for communication between hardware nodes and radio units.[000117] Although the computing devices described herein (e.g., UEs, network nodes) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or moreoperations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.[000118] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.Example Embodiments[000119] Provided below are possible, and non-limiting, examples of possible embodiments under the present disclosure.[000120] In a first embodiment, there is a method performed by a UE for detecting upcoming satellites. The method comprises receiving a new indication included in MBS control information that informs the UE which upcoming satellites provide the same MBS services as a current satellite in the same geographical area.[000121] A second embodiment can comprise the method of the first embodiment, wherein the new indication includes an expected time when those satellites start covering the same cell / intended service area.[000122] A third embodiment can comprise the method of the first or second embodiment, wherein the new indication is complemented with the satellite assistance information provided in other System Information blocks (e.g., SIB19).[000123] A fourth embodiment can comprise the method of any of the first to third embodiments, wherein the new indication comprises at least one of: a. Satellite service start time: The time instant when a satellite in the list starts serving the current cell or the service area or the intended service area associated with the MBS service. For example, a t-service parameter indicating when a certain satellite starts serving the same cell or service area as the current satellite / cell. b. Satellite ID: unique identifier for a satellite within a non-terrestrial network. c. Carrier frequency or PCI. d. Validity duration: Information about the satellite trajectory, e.g., in the form of at least one of: satellite ephemeris, a reference time, a validity timer that indicates the time duration during which the satellite trajectory information is valid. e. A message from at least one of: a network node; a satellite.[000124] A fifth embodiment can comprise the method of any of the first to fourth embodiments, wherein the previous satellite list can be associated with a geographic area, denominated as SSA.[000125] A sixth embodiment can comprise the method of any of the first to fifth embodiments, wherein the UE is informed of the list of satellites that belong to the SSA and may also be provided with the geographical coordinates of the SSA.[000126] A seventh embodiment can comprise the method of any of the first to fifth embodiments, wherein the UE can receive this information via Service Announcement (e.g., OTT means) or system information broadcast via its serving cell for both the serving cell and current and future neighbor cells.[000127] An eighth embodiment can comprise the method of any of the first to seventh embodiments, wherein as long as any current or future neighbor cells share, or any upcoming satellites, belong to the same SSA, the UE can expect the provided MBS broadcast services and / or MBS broadcast configuration (e.g., scheduling) to not to differ from the serving cell’s.[000128] A ninth embodiment can comprise the method of any of embodiments one to eight, wherein the SSA is associated with a unique identifier (e.g., represented with an INTEGER ASN.1 parameter).[000129] A tenth embodiment can comprise the method of the ninth embodiment, wherein the UE is not informed of the SSA geographic coordinates, nor the complete list of satellites in the SSA, but it is provided with the SSA’s identifier via the serving cell.[000130] An eleventh embodiment can comprise the method of the tenth embodiment, wherein as long as neighbor cells share the same SSA identifier, the UE can expect the provided MBS broadcast services and / or MBS broadcast configuration (e.g., scheduling) to not to differ from the serving cell’s.[000131] A twelfth embodiment can comprise the method of any of the first to eleventh embodiments, wherein the new indication informs the UEs that the same MBS configuration as the one used in the serving cell applies to the new cell served by the incoming satellite.[000132] A thirteenth embodiment can comprise the method of the twelfth embodiment, wherein the new indication only considers the very next incoming satellite / cell, which substitutes the serving cell due to the satellite movements (e.g., after the time denoted by t-service in SIB 19).[000133] A fourteenth embodiment can comprise the method of the twelfth or thirteenth embodiment, wherein the new indication pertains the whole NTN cell covering a certain geographic area (e.g., (quasi)-Earth fixed cells).[000134] A fifteenth embodiment can comprise the method of any of the twelfth to fourteenth embodiments, wherein the new indication can be included in the MBSBroadcastConfiguration IE provided in MCCH for MBS NTN.[000135] A sixteenth embodiment can comprise the method of any of the first to fifteenth embodiments, further comprising, the UE assuming that the target neighbor cell (i.e., served by one of the listed satellites in the indication) of a mobility procedure (e.g., cell reselection) provides the same MBS broadcast services and it can avoid read MBS broadcast related system information (e.g., SIB20) and MCCH configuration.[000136] A seventeenth embodiment can comprise the method of any of the first to sixteenth embodiments, wherein a UE can be configured or preconfigured to skip acquiring the list of neighbor satellites / cells providing the same MBS service if at least one of the following conditions is fulfilled:f. The UE has acquired such a list in the last T seconds (where T can be predefined in specifications or pre-configured in the UE (e.g., in a SIM card) or configurable by the network). g. The list contains at least N satellites or cells (N is a pre-defined or (pre- )configurable parameter). This corresponds to the case when the list contains a significant number of future satellites that can assure the UE to maintain the same MBS service for a certain period of time.[000137] An eighteenth embodiment can comprise the method of any of the first to seventeenth embodiments, wherein the list of satellites providing the same MBS service in the previous embodiments can be signaled in a system information block (SIB), a MCCH, a MAC CE, or in dedicated RRC signaling (e.g., in a RRCReconfiguration message).[000138] A nineteenth embodiment can comprise the method of any of the first to eighteenth embodiments, further comprising performing a mobility procedure (e.g., cell reselection) to a different cell provided by the same satellite.[000139] A twentieth embodiment can comprise a method performed by a network node for indicating upcoming satellites to a user equipment, UE, the method comprising transmitting a new indication included in MBS control information that informs the UE which upcoming satellites provide the same MBS services as a current satellite in the same geographical area.[000140] A twenty-first embodiment can comprise the method of the twentieth embodiment, wherein the network node comprises a satellite-based access node of a nonterrestrial network, NTN.[000141] A twenty-second embodiment can comprise the method of the twentieth or twenty-first embodiment, wherein the new indication includes an expected time when those satellites start covering the same cell / intended service area.[000142] A twenty -third embodiment can comprise the method of any of the twentieth to twenty-second embodiments, wherein the new indication is complemented with the satellite assistance information provided in other System Information blocks (e.g., SIB19).[000143] A twenty-fourth embodiment can comprise the method of any of the twentieth to twenty -third embodiments, wherein the new indication comprises at least one of: h. Satellite service start time: The time instant when a satellite in the list starts serving the current cell or the service area or the intended service area associated with the MBS service. For example, a t-service parameter indicating when acertain satellite starts serving the same cell or service area as the current satellite / cell. i. Satellite ID: unique identifier for a satellite within a non-terrestrial network. j. Carrier frequency or PCI. k. Validity duration: Information about the satellite trajectory, e.g., in the form of at least one of: satellite ephemeris, a reference time, a validity timer that indicates the time duration during which the satellite trajectory information is valid.[000144] A twenty-fifth embodiment can comprise the method of any of the twentieth to twenty-fourth embodiments, wherein the previous satellite list can be associated with a geographic area, denominated as Satellite Selection Area (SSA).[000145] A twenty-sixth embodiment can comprise the method of any of the twentieth to twenty-fifth embodiments, wherein the UE is informed of the list of satellites that belong to the SSA and may also be provided with the geographical coordinates of the SSA.[000146] A twenty-seventh embodiment can comprise the method of any of the twentieth to twenty-fifth embodiments, wherein the UE can receive this information via Service Announcement (e.g., OTT means) or system information broadcast via its serving cell for both the serving cell and current and future neighbor cells.[000147] A twenty-eighth embodiment can comprise the method of any of the twentieth to twenty-seventh embodiments, wherein as long as any current or future neighbor cells share, or any upcoming satellites, belong to the same SSA, the UE can expect the provided MBS broadcast services and / or MBS broadcast configuration (e.g., scheduling) to not to differ from the serving cell’s.[000148] A twenty-ninth embodiment can comprise the method of any of the twentieth to twenty-eighth embodiments, wherein the SSA is associated with a unique identifier (e.g., represented with an INTEGER ASN.l parameter).[000149] A thirtieth embodiment can comprise the method of the twenty-ninth embodiment, wherein the UE is not informed of the SSA geographic coordinates, nor the complete list of satellites in the SSA, but it is provided with the SSA’s identifier via the serving cell.[000150] A thirty-first embodiment can comprise the method of the thirtieth embodiment, wherein as long as neighbor cells share the same SSA identifier, the UE can expect the provided MBS broadcast services and / or MBS broadcast configuration (e.g., scheduling) to not to differ from the serving cell’s.[000151] A thirty-second embodiment can comprise the method of any of the twentieth to thirty-first embodiments, wherein the new indication informs the UEs that the same MBS configuration as the one used in the serving cell applies to the new cell served by the incoming satellite.[000152] A thirty -third embodiment can comprise the method of the thirty-second embodiment, wherein the new indication only considers the very next incoming satellite / cell, which substitutes the serving cell due to the satellite movements (e.g., after the time denoted by t-service in SIB 19).[000153] A thirty-fourth embodiment can comprise the method of any of the thirty-second to thirty -third embodiments, wherein the new indication pertains the whole NTN cell covering a certain geographic area (e.g., (quasi)-Earth fixed cells).[000154] A thirty-fifth embodiment can comprise the method of any of the thirty- second to thirty-fourth embodiments, wherein the new indication can be included in the MBSBroadcastConfiguration IE provided in MCCH for MBS NTN.[000155] A thirty-sixth embodiment can comprise the method of any of the twentieth to thirty-fifth embodiments, wherein the UE assumes that the target neighbor cell (i.e. , served by one of the listed satellites in the indication) of a mobility procedure (e.g., cell reselection) provides the same MBS broadcast services and it can avoid read MBS broadcast related system information (e.g., SIB20) and MCCH configuration.[000156] A thirty-seventh embodiment can comprise the method of any of the twentieth to thirty-sixth embodiments, wherein a UE can be configured or preconfigured to skip acquiring the list of neighbor satellites / cells providing the same MBS service if at least one of the following conditions is fulfilled: l. The UE has acquired such a list in the last T seconds (where T can be predefined in specifications or pre-configured in the UE (e.g., in a SIM card) or configurable by the network). m. The list contains at least N satellites or cells (N is a pre-defined or (pre- )configurable parameter). This corresponds to the case when the list contains a significant number of future satellites that can assure the UE to maintain the same MBS service for a certain period of time.[000157] A thirty-eighth embodiment can comprise the method of any of the twentieth to thirty-seventh embodiments, wherein the list of satellites providing the same MBS service in the previous embodiments can be signaled in a system information block (SIB), a MCCH, a MAC CE, or in dedicated RRC signaling (e.g., in a RRCReconfiguration message).[000158] A thirty -ninth embodiment can comprise the method of any of the twentieth to thirty-eighth embodiments, wherein the UE performs a mobility procedure (e.g., cell reselection) to a different cell provided by the same satellite.[000159] A fortieth embodiment can comprise a method performed by a satellitebased access node of a non-terrestrial network, NTN, the method comprising: transmitting, for a wireless communication device when the wireless communication device is served by a satellite footprint or spot beam generated by the NTN, a new indication included in MBS control information that informs which upcoming satellites provide the same MBS services as a current satellite in the same geographical area.[000160] A forty-first embodiment can comprise a method performed by a satellite-based access node of a non-terrestrial network, NTN, the method comprising: transmitting to a wireless communication device served by a satellite footprint or spot beam comprised in the NTN a new indication of upcoming satellites.[000161] A forty-second embodiment can comprise a UE for detecting upcoming satellites, comprising: processing circuitry configured to perform any of the steps of any of the first to nineteenth embodiments; and power supply circuitry configured to supply power to the processing circuitry.[000162] A forty -third embodiment can comprise a network node for indicating upcoming satellites to a UE, the network node comprising: processing circuitry configured to perform any of the steps of any of the twentieth to forty-first embodiments; power supply circuitry configured to supply power to the processing circuitry.[000163] A forty-forth embodiment can comprise a UE for detecting upcoming satellites, the UE comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform any of the steps of any of the first to nineteenth embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE.[000164] A forty -fifth embodiment can comprise a satellite for indicating upcoming satellites to a UE, the network node comprising: processing circuitry configured toperform any of the steps of any of the twentieth to forty-first embodiments; power supply circuitry configured to supply power to the processing circuitry.

Claims

CLAIMSWhat is claimed is:

1. A method (2200) performed by a user equipment, UE (3200), for receiving a multimedia broadcast service, MBS in a non-terrestrial network, NTN (3100), based communication system, the method comprising: receiving (2210) an indication for service continuity between one or more current serving cells providing the MBS and a future NTN cell / footprint provided by a non-geostationary orbiting satellite.

2. The method according to claim 1, wherein the indication is included in MBS control information.

3. The method according to claim 1 or 2, wherein the indication comprises a MBSBroadcastConfiguration IE.

4. The method according to any of claims 1 to 3, wherein the indication informs the UE that a MBS configuration of the one or more current serving cells applies to the future NTN cell / footprint.

5. The method according to any of claims 1 to 4, wherein the indication informs the UE which upcoming satellites provide the MBS services comprising the MBS configuration according to the current serving satellite in the current geographical area.

6. The method according to any of claims 1 to 5, wherein the indication is complemented with one or more satellite assistance information provided in one or more System Information blocks, SIBs.

7. The method according to any of claims 1 to 6, wherein the indication comprises at least one of: a satellite service start time; a satellite identifier; a carrier frequency; a physical cell identity, PCI; a validity duration; a satellite ephemeris; a reference time; a validity time; a message from a network node; a message from a satellite.

428. The method according to any of claims 1 to 7, wherein the indication only considers a very next incoming satellite or cell to substitute for the one or more current serving cells.

9. The method according to any of claims 1 to 8, further comprising: skipping system information acquisition based on the received indication.

10. The method according to any of claims 1 to 9, wherein the future NTN cell / footprint is associated with a Satellite Selection Area, SSA, wherein the indication identifies at least one of; one or more satellites associated with the SSA; and / or one or more geographical coordinates associated with the SSA.

11. The method according to claim 10, wherein the indication is received via at least one of: MBS control information; Non-access Stratum, NAS; a Service announcement.

12. The method according to claim 10 or 11, wherein any cell associated with the SSA has the same one or more MBS traffic channel, MTCH, configuration parameters as the one or more current serving cells.

13. The method according to any of claims 10 to 12, wherein the SSA is associated with a unique identifier.

14. The method according to any of claims 10 to 13, wherein the UE is provided with an identifier of the SSA via a serving cell.

15. The method according to any of claims 10 to 14, further comprising: acquiring a list of any of the one or more satellites that provide the same MBS services as the one or more current serving cells.

16. The method according to any of claims 10 to 15, wherein the UE is configured to skip acquiring a list of any of the one or more satellites that provide the same MBS services as the one or more current serving cells, if at least one of the following conditions is fulfilled: the UE has acquired such a list in the last T seconds, wherein T can be at least one of; pre-defined in specifications, pre-configured in the UE, or configurable by a network; or43the list contains at least N satellites or cells, wherein N can be at least one of; pre-defined in specifications, pre-configured in the UE, or configurable by a network.

17. The method of claim 15, wherein the list is received via at least one of: a system information block, SIB; a MBS Control Channel, MCCH; a Medium Access Control, MAC CE; dedicated Radio Resource Control, RRC, signaling.

18. The method of any of embodiments 1 to 17, further comprising: performing a mobility procedure to a different cell provided by a serving satellite or a different satellite.

19. A method (2600) performed by a network node (3300) for indicating upcoming satellites to a user equipment, UE, the method comprising: transmitting (2610) an indication that informs the UE which upcoming satellites provide the same MBS services as a current satellite in the same geographical area.

20. The method according to claim 19, wherein the indication is included in at least one of: an information element, IE; MBS control information.

21. The method according to claim 19 or 20, wherein the indication comprises a MBSBroadcastConfiguration information element, IE.

22. The method according to any of claims 19 to 21, wherein the indication informs the UE that a MBS configuration of the one or more current serving cells applies to the future NTN cell / footprint.

23. The method according to any of claims 19 to 22, wherein the indication comprises at least one of: a satellite service start time; a satellite identifier; a carrier frequency; a physical cell identity, PCI; a validity duration; a satellite ephemeris; a reference time; a validity time; a message from a network node; a message from a satellite.

24. The method according to any of claims 19 to 23, wherein the network node comprises a satellite-based access node of a non-terrestrial network, NTN.4425. The method according to any of claims 19 to 24, wherein the indication is for service continuity between one or more current serving cells providing MBS and a Satellite Selection Area, SSA, and wherein the indication identifies at least one of; one or more satellites associated with the SSA; and / or one or more geographical coordinates associated with the SSA.

26. The method according to claim 25, wherein the indication is transmitted via at least one of: Multimedia Broadcast Service, MBS, control information; Non-access Stratum, NAS; a Service Announcement.

27. The method according to claim 25 or 26, wherein any cell associated with the SSA has the same one or more MBS traffic channel, MTCH, configuration parameters as the one or more current serving cells.

28. The method according to any of claims 25 to 27, wherein the SSA is associated with a unique identifier.

29. The method according to any of claims 25 to 28, wherein the UE is provided with an identifier of the SSA via a serving cell.

30. A user equipment, UE (3200), for detecting upcoming satellites, comprising: processing circuitry (3202) configured to perform any of the steps of any of embodiments 1 to 18; and power supply circuitry (3208) configured to supply power to the processing circuitry.

31. A network node (3300) for indicating upcoming satellites to a user equipment, UE, the network node comprising: processing circuitry (3302) configured to perform any of the steps of any of embodiments 19 to 29; power supply circuitry (3308) configured to supply power to the processing circuitry.

32. The network node of claim 31, wherein the network node comprises a satellite.

33. A user equipment, UE (3200), for receiving a multimedia broadcast service, MBS in a non-terrestrial network, NTN, based communication system, comprising: processing circuitry (3202); and a memory (3210) storing instructions whereby the processing circuitry is operable to perform the steps of: receiving an indication for service continuity between one or more current serving cells providing the MBS and a future NTN cell / footprint provided by a non-geostationary orbiting satellite.

34. A network node (3300) for indicating upcoming satellites to a user equipment, UE, comprising: processing circuitry (3302); and a memory (3304) storing instructions whereby the processing circuitry is operable to perform the steps of: transmitting an indication that informs the UE which upcoming satellites provide the same MBS services as a current satellite in the same geographical area.

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