Methods for idle and inactive mode operation in store and forward networks

Abstract

A method of a user equipment (UE) for operating in a wireless communications network, the wireless communications network including one or more non-terrestrial network (NTN) store and forward (S&F) ce

Description

BACKGROUND Field

[0001] The present disclosure relates to methods and apparatus for idle and inactive mode operation in store and forward networks. Description of Related Art

[0002] The content of the following documents is referred to below and / or their content provides background information and context that the following disclosure should be considered in view of: 3GPP TS 36.331 V18.2.0 July 2024 3GPP TS 36.304 V18.2.0 July 2024 RP-202689, RAN Meeting #90 December 2020 RP-211557, RAN Meeting #91-e March 2021 RP-220953, RAN Meeting #95-e March 2022 RP-223519, RAN Meeting #98-e December 2022 RP-234077 RAN Meeting #102 December 2023 (Note: the example versions shown for each TS are non-limiting, other versions of the TS may be considered also)

[0003] Wireless or mobile (cellular) communications networks in which a mobile terminal (e.g., user equipment (UE), such as a mobile handset) communicates via a radio link with a network of base stations, or other wireless access points or nodes, have undergone rapid development through a number of generations. The 3rd Generation Partnership Project (3GPP) design, specify and standardise technologies for mobile wireless communication networks. Fourth Generation (4G) and Fifth Generation (5G) systems are now widely deployed, and development of Sixth Generation (6G) Systems is in progress.

[0004] 3GPP standards for 4G systems include an Evolved Packet Core (EPC) and an Enhanced-UTRAN (E-UTRAN: an Enhanced Universal Terrestrial Radio Access Network). The E-UTRAN uses Long Term Evolution (LTE) radio technology. LTE is commonly used to refer to the whole system including both the EPC and the E-UTRAN, and LTE is used in this sense in the remainder of this document. LTE should also be taken to include LTE enhancements such as LTE Advanced and LTE Pro, which offer enhanced data rates compared to LTE.

[0005] In 5G systems a new air interface has been developed, which may be referred to as 5G New Radio (5G NR) or simply NR. NR is designed to support the wide variety of services and use case scenarios envisaged for 5G networks, though builds upon established LTE technologies. New frameworks and architectures are also being developed as part of 5G networks in order to increase the range of functionality and use cases available through 5G networks.

[0006] In recent years, Non-Terrestrial Network (NTN) networks have been considered and their operation integrated into 3GPP systems in order to enhance coverage and / or provide alternative coverage mechanisms. The adaptation of Internet of Things (loT) devices for operation with NTNs is also being considered. Internet of Things (loT) Non-Terrestrial Networks (NTNs)

[0007] Internet of Things (loT) NTN was a 3GPP study and work item in 3GPP release 17 to provide NTN access for E-UTRAN loT devices (NB-loT and LTE-M / eMTC) [RP-202689], NR NTN was a work item in Rel-17 to specify adaptation to allow NR to function over NTN [RP-211557], NTN access may be through Lower Earth Orbit (LEO), Medium Earth Orbit (MEO) and Geostationary Orbit (GEO), as well as through High-Altitude Platform Systems (HAPS).

[0008] Following the Work items in Release 17 there were work items to enhance NR NTN [RP-220953] and loT NTN [RP-220979] in Release 18.

[0009] The work item description for loT NTN Rel-19 is the following [RP-234077]: • Support of Store&Forward (S&F) satellite operation with full eNB as regenerative payload, therefore: o Define the necessary enhancements into E-UTRAN (network &UE) to support S&F operation for delay-tolerant services [RAN3, RAN2, RAN4] ■ At least specify necessary enhancements e.g. related to SI protocol, especially to address the feeder link switch over as needed [RAN3] Note: Strive to minimise UE impact. Note: Coordination with SA2 (Rel-19 SA2 led Sat-Arch ph3 SI) is needed on the detail requirements (e.g. traffic type, or QoS parameters for S&F), network architecture (e.g. whether consider (partial) core network on satellite) etc.; further coordination with CT1 might be required • Support of Capacity enhancements for uplink o Study then specify, if beneficial, enhancements to enable multiplexing of multiple UEs (e.g. up to the min of 4 and the maximum allowed by the existing UE and DE signalling) in a single 3.75 kHz or 15 kHz subcarrier via orthogonal cover codes (OCC) for NPUSCH format 1 and NPRACH [RANI, RAN2] ■ Multi-tone support for 15 kHz SCS should also be considered Note: Impact of impairment shall be taken into account o Study and specify, if beneficial the following enhancements to reduce the necessary uplink and downlink signaling to complete an EDT transaction [RAN2]: ■ Msg3 transmission without msgl / RAR ■ Efficient delivery (reduced overhead) ofmsg4 / RRCEarlyDataComplete

[0010] Figure 1 provides an illustration of an example NTN where a gateway (GW) 106 provides a feeder link 108 to a satellite 110 and the satellite provides an NTN cell 114 and an access link 116 to a device, such as a UE, within the NTN cell. The gateway may be connected to a gNB / eNB 104 which in turn is connected to a core network 102. The gateway 106 may be part of the gNB / eNB 104, separate to or partially integrated. Some of the functions of the gNB / eNB may also be implemented in the satellite 110 in some examples. Narrowband Internet of Things and LTE-M

[0011] Narrowband Internet of Things (NB-loT) is a 3GPP-defined network based on 4G E-UTRAN that supports ultra-low complexity devices with very narrow bandwidth that was introduced in 3GPP Release 13. The use case of NB-loT is to serve massive loT application, where requirements for instance are to support enhanced coverage, power-efficient operation and a massive number of devices. Some of the features introduced are: Support for enhanced coverage through low bandwidth and extreme amounts of repetitions. Power efficient operation by allowing the UE to sleep for very long times, relaxed requirements and more efficient signal to establish with a cell.

[0012] LTE-M (LTE-Machine) or eMTC (enhanced Machine Type Communication) is a 3GPP-defined network that is an extension of 4G E-UTRAN that supports low-complexity devices with more narrow bandwidths compared to normal LTE and further simplifications of procedures. Similarly to NB-loT, the use case is to serve massive loT, but with more capabilities. Instead of being an entirely new type of device with major air interface changes as in NB-loT, the LTE-M inherits most features of a regular LTE device, but with some adaptations for low complexity considerations. Idle and Inactive Mode Operation

[0013] RRC Idle mode (i.e. idle mode) and / or RRC inactive mode (i.e. inactive mode) mobility are based on a UE autonomously performing measurements and deciding according to some rules whether a UE shall re-select to another cell or not to camp on.

[0014] During cell selection, the UE identifies suitable cells, which is according to a cell suitability criteria based on signal strength and signal quality measurements. After identifying one or several suitable cells, the UE can choose any of them. For instance the UE can select the cell with the strongest signal strength and signal quality within a PLMN. Cell selection can be performed following PLMN selection (which may be after a UE is turned on), after being released by a network, or during the RRC re-establishment procedure and a number of other cases.

[0015] A cell may be classified into a number of different types of cells with respect to a UE. A suitable cell is a cell that fulfils the cell selection criteria, the cell is not barred etc. and is part of the tracking area of the UE - thus a normal type of cell. An acceptable cell is a cell on which the UE is only allowed to camp for specific reasons such as emergency cases, but the cell cannot be barred and the cell selection criteria need to be fulfilled. A UE only camps on such a cell if it cannot find a suitable cell. A reserved cell is a reserved cell if the system information indicates that it is reserved.

[0016] When camped on a cell, the UE shall perform the cell reselection procedures which includes searching and detecting cells and camping on a better or more suitable cell. In the cell reselection procedure, the UE searches intra-frequency cells, interfrequencies cells and inter-RAT cells following the signalling by the serving cell. Each frequency (inter-RAT or intra-RAT) may have a specific cell reselection priority. The cell reselection algorithm is designed to ensure that the UE chooses a cell with highest priority, given that it is not barred or not not allowed to camp on. A UE shall always select an inter-frequency or inter-RAT cell with a higher priority over a lower priority cell. If frequencies of equal priority are detected, then the UE shall rank all of the cells, where the ranking metric is based on signal strength and signal quality measurements and then choose the best candidate. The UE then camps on the newly re-selected cell.

[0017] There are also certain rules on for how long a new cell shall be better than the serving cell before camping on the new cell. This parameter is called Treselection and can be specific for a RAT or for other cases. There are also thresholds for the signal strength and / or signal quality that may need to be fulfilled before selecting a new cell to camp on, which may depend on whether the cell is lower or higher priority, and depend on whether the cell is inter-frequency or inter-RAT.

[0018] As part of the idle mode and inactive mode procedures, the UE also checks whether a cell is barred or not. If a cell is barred, the UE is not allowed to connect to the cell, not allowed to camp or consider the cell for cell reselection. In 4G, the barring bit is signalled in SIB1 while in 5G NR, the barring bit is signalled in MIB.

[0019] Inter-RAT may be considered any other than the current RAT. As an example for 4G E-LITRA UE, the following may be considered inter-RAT: 2G, 3G, 4G NB-loT, 5G NR or6G. Discontinuous Coverage

[0020] Discontinuous coverage is the scenario in which a LEO or MEO satellite network is not able to provide continuous coverage due to not having enough satellites to cover the whole earth and / or the coverage area of a satellite moving. As the coverage moves, this means that coverage will be on and off from the point of view of a UE. This is illustrated in Figures 2a and 2b where the reference signal received power (RSRP) of the UE 202 of satellite #1 204 that provides sat cell #1 and satellite #2 206 that provides sat cell #2 goes below a required threshold 208 thus not being able provide coverage to the UE 202 (i.e. the UE goes out of coverage). As an example, if there is only a single LEO satellite, the UE may see coverage as seldom as once every 24 hours for several minutes depending on the satellite coverage characteristics.

[0021] To allow for power saving when there is no coverage, the UE is allowed to power down and not perform any Access Stratum (AS) functionality, such as measuring and trying to detect cells, also known as idle mode tasks. For the UE to be able to know when there is coverage or not, the network signals long-term ephemeris parameters that allow the UE to predict future satellite passes up to several days in the future. This is then used when the UE stops perform idle mode tasks on NTNs. This ephemeris information is signalled in a new System information block (SIB) SIB32. In addition to ephemeris parameters, the network also signals coverage parameters that tells the UE how large the coverage is to better be able to estimate whether a satellite will provide coverage or not.

[0022] The SIB32 consists of the following: - System lnformationBlockType32 The IE SystemInformationBlockType32 contains satellite assistance information for prediction of discontinuous coverage. SystemlnformationBlockType32 is only signalled in a NTN cell. SystemlnformationBlockType32 information element — ASN1START SystemInformationBlockType32-rl7 ::= SEQUENCE { satelliteInfoList-rl7 lateNonCriticalExtension [ [ satellitelnfoList-vlSOO J J } SatelliteInfoList-rl7 ::= SEQUENCE SatellitelnfoList-vlSOO ::= SEQUENCE SatelliteInfoList-rl7 OPTIONAL, — Need OR OCTET STRING OPTIONAL, SatellitelnfoList-vlSOO OPTIONAL — Need OR (SIZE (1..maxSat-rl7)) OF Satellitelnfo-rl7 (SIZE (1..maxSat-rl7)) OF CarrierFreqList-vl800 Satellitelnfo-rl7 ::= satelliteld-rl7 servicelnfo-rl7 SEQUENCE { INTEGER (0..255), SEQUENCE { tie-Ephemeris Parameters-r17 TLE-EphemerisParameters-r17 OPTIONAL, t-ServiceStart-rl7 TimeOffsetUTC-rl7 OPTIONAL -- Need OR -- Need OR b footprintlnfo-rl7 SEQUENCE { referencePoint-rl7 SEQUENCE { longitude-rl7 INTEGER (-131072..131071), latitude-rl7 INTEGER (-131072..131071) } OPTIONAL, — Need OR elevationAngles-rl7 SEQUENCE { elevationAngleRight-rl7 INTEGER (-14..14), elevationAngleLeft-rl7 INTEGER (-14..14) } OPTIONAL, — Need OR radius-rl7 INTEGER (1..256) OPTIONAL OPTIONAL -- Need OP -- Need OR CarrierFreqList-vl800 ::= SEQUENCE (SIZE (1..maxFreq)) OF ARFCN-ValueEUTRA — ASN1STOP [ System lnformationBlockType32 field descriptions i carrierFreqList ) ( Includes a list of E-UTRAfrequencies, see TS 36.304 [4], i elevationAngleLeft, elevationAngleRight I Leftmost and rightmost (with reference to the satellite direction) elevation angle. Unit in degree. I Step of 5 degree. Actual value = field value * 5. i If the field elevationAngleLeft is absent, the leftmost elevation angle is equal to the value of field [ elevationAngleRight. i i fooiprintinfo I Satellite footprint. i E-UTRAN may configure elevationAngles and / or radius for earth moving cell. I E-UTRAN may configure referencePoint and radius for quasi-earth fixed cell. i latitude I Latitude of the reference point. Unit in degree. I Step of 3601262144 degree. Actual value = field value * (3601262144). I longitude I Longitude of the reference point. Unit in degree. i Step of 3601262144 degree. Actual value = field value * (3601262144). i radius i Distance between the reference point and the edge of the satellite or beam coverage. Unit in km. I Step of 10 km. Actual value = field value * 10. i satellitelnfoList I List of satellite information. If E-UTRAN includes satellitelnfoList-v1800, it includes the same number of entries, i and listed in the same order, as in satellitelnfoList-r17. I serviceinfo i Information on when the satellite will provide coverage. I E-UTRAN always configures tle-EphemerisParameters for a satellite with earth moving cell(s) and always i configures t-ServiceStart for a quasi-earth fixed cell. I tle-EphemerisParameters i Mean values of the satellite orbital parameters based on the TLE set format for estimating in-coverage and out- I of-coverage periods for a satellite with earth moving cell(s), see TS 36.304 [4], i i-ServiceSiari I Time information on when the incoming satellite is going to start serving the area for quasi-earth fixed cell. Store and Forward Non-Terrestrial Networks

[0023] Store &Forward (S&F) allows satellites to store UE data and transmit it when connected to ground stations or UE. Therefore, S&F means a satellite providing an NTN cell does not require a simultaneous service link and feeder link in order to provide communications to a UE.

[0024] Although the concepts of NTN, S&F, RRC idle and inactive modes have previously been defined, their integration with one another and optimisation of their integrated operation requires further definition. SUMMARY

[0025] The present disclosure provides approaches for RRC idle and RRC inactive mode operation in Store and Forward networks.

[0026] In accordance with an aspect of the present disclosure, there is provided a method of a user equipment (UE) for operating in a wireless communications network, the wireless communications network including one or more non-terrestrial network (NTN) store and forward (S&F) cells, the method comprising: receiving an indication of one or more satellites providing the NTN S&F cells; receiving, from the network, satellite assistance information on the one or more of the indicated satellites; and performing an idle mode operation based on the received satellite assistance information.

[0027] In an example, performing an idle mode operation based on the received satellite assistance information includes performing an idle mode operation when in coverage of the one or more satellites providing the NTN S&F cells.

[0028] In an example, performing an idle mode operation based on the received satellite assistance information includes not performing an idle mode operation when not in coverage of the one or more satellite providing the NTN S&F cells.

[0029] In an example, the UE enters a reduced power mode (e.g. a sleep mode or a discontinuous coverage mode) outside coverage of the one or more satellites providing the NTN S&F cells.

[0030] In an example, the UE wakes up from a reduced power mode when in coverage of the one or more satellite providing the NTN S&F cells.

[0031] In an example, the receiving an indication of one or more satellites providing the NTN S&F cells includes receiving a non-access stratum (NAS) message from the network including an indication of the one or more satellites providing the NTN S&F cells.

[0032] In an example, the NAS message is received from a mobility management entity (MME) of the network.

[0033] In an example, the satellite assistance information is received in broadcast information from the network.

[0034] In an example, the satellite assistance information is received in system information broadcast by the network.

[0035] In an example, the satellite assistance information includes ephemeris information and service start time information.

[0036] In an example, the method further includes determining a coverage of the one or more NTN S&F cells based on the satellite assistance information.

[0037] In an example, the satellite assistance information is received from an S&F eNB.

[0038] In an example, the receiving, from the network, satellite assistance information on the one or more of the indicated satellites includes receiving satellite assistance information for the indicated satellites the UE lacks satellite assistance information on.

[0039] In an example, the method further comprises transmitting, to the network, an indication of the satellite(s) the UE lacks satellite assistance information on.

[0040] In an example, the indication of the satellite(s) the UE lacks satellite assistance information on includes satellite ID(s) of the satellite(s) the UE lacks satellite assistance information on.

[0041] In an example, the indication of the satellite(s) the UE lacks satellite assistance information on is sent via a radio resource control (RRC) message.

[0042] In an example, the method further comprises: receiving, from the network, a request to check if the UE lacks satellite assistance information on the one or more satellites providing the NTN S&F cells; checking if the UE lacks satellite assistance information on the one or more satellites providing the NTN S&F cells; and if the UE lacks satellite assistance information on the one or more satellites providing the NTN S&F cells, transmitting, to the network, the indication of the satellites the UE lacks satellite assistance information on.

[0043] In an example, the indication of one or more satellites providing the NTN S&F cells includes a list of one or more satellite IDs.

[0044] In an example, the UE is a Internet of Things (loT) device.

[0045] In an example, the idle mode operation includes performing measurements on an NTN cell for cell selection.

[0046] In accordance with a second aspect of the present disclosure, there is provided a user equipment (UE) for operating in a wireless communications network, the wireless communications network including one or more non-terrestrial network (NTN) store and forward (S&F) cells, wherein the UE is configured to perform the method of any preceding claim.

[0047] Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Embodiments / examples of the present disclosure are further described hereinafter with reference to the accompanying drawings, in which: Figure 1 provides a diagram of an example non-terrestrial network (NTN); Figures 2a and 2b provide diagrams illustrating discontinuous coverage in an NTN network; Figures 3a, 3b, and 3c provide diagrams illustrating examples of a full coverage NTN network, a discontinuous coverage NTN network, and a store and forward (S&F) discontinuous coverage NTN network; Figure 4 provides a flow diagram illustrating an example of cell barring in an S&F network; Figure 5 provides a diagram illustrating enhancements to idle mode operation in an S&F network; Figure 6 provides a diagram illustrating an example provision of satellite information in an S&F network; Figure 7 provides a diagram illustrating an example provision of satellite information in an S&F network; and Figure 8 provides a block diagram of an exemplary network entity / function that may be used in certain examples of the present disclosure. DETAILED DESCRIPTION

[0049] The following description of examples of the present disclosure, with reference to the accompanying drawings, is provided to assist in a comprehensive understanding of certain examples of the present disclosure. The description includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the examples described herein can be made without departing from the scope of the invention or disclosure.

[0050] The same or similar components may be designated by the same or similar reference numerals, although they may be illustrated in different drawings.

[0051] Detailed descriptions of techniques, structures, constructions, functions or processes known in the art may be omitted for clarity and conciseness, and to avoid obscuring the subject matter of the present disclosure.

[0052] The terms and words used herein are not limited to the bibliographical or standard meanings, but are merely used to enable a clear and consistent understanding of the disclosure.

[0053] Throughout the description of this specification, the words “comprise”, “include” and “contain” and variations of the words, for example “comprising” and “comprises”, means “including but not limited to”, and is not intended to (and does not) exclude other features, elements, components, integers, steps, processes, operations, functions, characteristics, properties and / or groups thereof.

[0054] Throughout the description of this specification, the singular form, for example “a”, “an” and “the”, encompasses the plural unless the context otherwise requires. For example, reference to “an object” includes reference to one or more of such objects.

[0055] Throughout the description, the expression “at least one of A, B and / or C” (or the like) and the expression “one or more of A, B and / or C” (or the like) should be seen to separately include all possible combinations, for example: A, B, C, A and B, A and C, A and B and C.

[0056] Throughout the description of this specification, language in the general form of “X for Y” (where Y is some action, process, operation, function, activity or step and X is some means for carrying out that action, process, operation, function, activity or step) encompasses means X adapted, configured or arranged specifically, but not necessarily exclusively, to do Y.

[0057] Features, elements, components, integers, steps, processes, operations, functions, characteristics, properties and / or groups thereof described or disclosed in conjunction with a particular aspect, embodiment or example are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

[0058] The following examples are applicable to, and use terminology associated with, 3GPP 4G (e.g., LTE) and / or 5G (e.g., NR). However, the skilled person will appreciate that the techniques disclosed herein are not limited to these examples or to 3GPP 4G (e.g., LTE) and / or 5G (e.g., NR), and may be applied in any suitable system or standard, for example one or more existing and / or future generation wireless communication systems or standards (e.g., B5G, 5G-Advanced, 6G etc.). The skilled person will appreciate that the 1 lechniquees disclosed herein may be applied in any existing or future releases of 3GPP 4G (e.g., LTE) and / or 5G (e.g., NR) and / or 5G Advanced and / or 6G, and / or (3GPP Release 17, 18, 19, 20, etc.) or any other relevant standard. For example, the functionality of the various network entities and other features disclosed herein may be applied to corresponding or equivalent entities or features in other communication systems or standards. Corresponding or equivalent entities or features may be regarded as entities or features that perform the same or similar role, function, operation or purpose within the network.

[0059] Furthermore, the following also applies to the present disclosure: • The terms functionality / use-case / configuration / scenario / site may be used interchangeably. • The terms model and model functionality may be used interchangeably. • This disclosure also apply to non-3GPP entities. • The concepts, proposals, solutions, methods, embodiments, figures, and / or examples, presented in this disclosure, would apply to various type of communication systems, such as 4G, 4G-Advanced, 5G, 5G-Advanced, and 6G.

[0060] A particular network entity may be implemented as a network element on dedicated hardware, as a software instance running on a dedicated hardware, and / or as a virtualised function instantiated on an appropriate platform, e.g. on a cloud infrastructure.

[0061] The skilled person will appreciate that the present disclosure is not limited to the specific examples disclosed herein. For example: • The techniques disclosed herein are not limited to 3GPP 4G or 5G or 5G-Advanced and also apply to B5G and 6G systems. • One or more entities in the examples disclosed herein may be replaced with one or more alternative entities performing equivalent or corresponding functions, processes or operations. • One or more of the messages in the examples disclosed herein may be replaced with one or more alternative messages, signals or other type of information carriers that communicate equivalent or corresponding information. • One or more further elements, entities and / or messages may be added to the examples disclosed herein. • One or more non-essential elements, entities and / or messages may be omitted in certain examples. • The functions, processes or operations of a particular entity in one example may be divided between two or more separate entities in an alternative example. • The functions, processes or operations of two or more separate entities in one example may be performed by a single entity in an alternative example. • Information carried by a particular message in one example may be carried by two or more separate messages in an alternative example. • Information carried by two or more separate messages in one example may be carried by a single message in an alternative example. • The order in which operations are performed may be modified, if possible, in alternative examples. • The transmission of information between network entities is not limited to the specific form, type and / or order of messages described in relation to the examples disclosed herein.

[0062] Certain examples of the present disclosure may be provided in the form of an apparatus / device / network entity configured to perform one or more defined network functions and / or a method therefor. Such an apparatus / device / network entity may comprise one or more elements, for example one or more of receivers, transmitters, transceivers, processors, controllers, modules, units, and the like, each element configured to perform one or more corresponding processes, operations and / or method steps for implementing the techniques described herein. For example, an operation / function of X may be performed by a module configured to perform X (or an X-module). Certain examples of the present disclosure may be provided in the form of a system (e.g., a network) comprising one or more such apparatuses / devices / network entities, and / or a method therefor.

[0063] It will be appreciated that examples of the present disclosure may be realized in the form of hardware, software or a combination of hardware and software. Certain examples of the present disclosure may provide a computer program comprising instructions or code which, when executed, implement a method, system and / or apparatus in accordance with any aspect, example and / or embodiment disclosed herein. Certain embodiments of the present disclosure provide a machine-readable storage storing such a program. Non-Terrestrial and Store and Forward Networks

[0064] In Release 17 loT NTN Wl, the concept of discontinuous coverage was introduced. While discontinuous coverage allows for UE power savings in deployments where there are not enough satellites to cover the whole earth, there are still some basic issues in order to provide cost-effective loT NTN solutions. The main issue is that the satellites providing discontinuous coverage still need to have connectivity with a ground gateway in order to perform any type of communication. If one only considers coverage, the amount of ground stations are still the same for a discontinuous coverage satellite network as a fully continuous coverage network. This can be seen in Figures 3a, 3b, and 3c.

[0065] Figure 3a shows a case of continuous coverage, where each satellite 307 is connected to one of the three ground stations (or ground gateways) 301, 303, 305 (note: numeral 307 is used for each of the twelve satellites illustrated in Figure 3a, but alternatively these satellites could be individually numbered 307-1, 307-2, ..., 307-n, where n is equal to the total number of satellites). A corresponding cell or coverage is shown for each satellite 307.

[0066] In Figure 3b, a case of discontinuous coverage is shown with only four satellites 317 (this number is arbitrarily chosen to demonstrate discontinuous coverage); however, three ground stations (or ground gateways) 311, 313, 315 are still provided, with each satellite 317 connected to one of the three base stations 311, 313, 315 (note: numeral 317 is used for each of the four satellites illustrated in Figure 3b, but alternatively these satellites could be individually numbered 317-1, 317-2, ..., 317-m, where m is equal to the total number of satellites). A corresponding cell or coverage is again shown for each satellite 317

[0067] In Figure 3c, a case of discontinuous coverage with store and forwarding (S&F) is shown, where the satellites 327 that are providing the discontinuous coverage only temporarily connect with a ground station / network, during which time data may communicated between the satellite and the ground station 321. For instance, the satellites may only be connected with a ground station when they are in certain regions and / or within range for example. In other words, S&F refers to providing a communication service for UEs under satellite coverage without a simultaneous active feeder link between the satellite and a ground station.

[0068] Among others, two notable aspects of an S&F cell or a satellite operating with S&F are as follows. One aspect is that the full base station, i.e. a regenerative architecture, is on the satellite. This means that the eNB or gNB is in the satellite, which is different from the first release of NTN, which introduced transparent payload. Another aspect is that either the full core network, or part of the core network is in the satellite to enable some type of communication. Altogether, since the cell does not have connectivity to the outer world, this would mean that communication with a server or application on earth would naturally be very slow or only suitable to single messages being reported, such as loT applications.

[0069] Accordingly, one issue with an S&F cell is that among all options of different cells, such as terrestrial cells, NTN cells, discontinuous coverage NTN cell and S&F cells, it is likely that S&F cells will offer the lowest QoS. This is because NTN is already expected to provide lower QoS, and an S&F cell does not have full network connectivity. Therefore, an S&F cell should preferably be the cell of lowest priority. Due to these aspects of S&F cells, in this disclosure approaches for idle and inactive mode methods to allow an S&F cell to be well-integrated into a network given its characteristics.

[0070] Accordingly, the present disclosure provides approaches for idle mode and inactive mode operation in store and forward networks.

[0071] Terms including S&F Cell, Non-S&F Cell, NTN Cell, and TN Cell used in the present disclosure should taken in the following context.

[0072] S&F Cell: In the present disclosure, an S&F cell is a cell that either is capable of S&F operation with other network nodes and UEs, or temporarily operates as an S&F cell. While in the present disclosure the S&F cell may be seen as a permanent condition, it may also be that the S&F cell is something temporary when the S&F cell or any cell does not have ground network and / or full core network connectivity. This may imply that the S&F status changes. A cell may also be considered an S&F cell if the cell does not have ground network and / or full core network connectivity. In this instance, the condition “If the cell is an S&F cell”, may taken as “if the cell does not have ground connectivity” or “if the S&F cell does not have full core network connectivity”. This may imply that there is information that indicates when a cell may or may not have ground connectivity, which the UE may compute on its own. For instance the network may indicate times when the cell may be considered to operate and not operate (e.g. an end time) as an S&F cell. An S&F-cell may also be a cell that signals an indication that it is an S&F-cell. This may for instance be that it signals the barring indication (which may be barred, notBarred or any other indication).

[0073] Non-S&F Cell: Any cell that is not an S&F cell, or a cell that has ground connectivity, or full core network connectivity. This can be an NTN cell, a terrestrial cell, an ATG cell or similar and of any radio access technology.

[0074] NTN Cell: A cell that operates over NTN. This can also be defined as a cell that indicates the field cellBarred-NTN. This can be a 4G loT NTN, 5G NR or 6G NTN cell. This category may also encompass S&F cells.

[0075] TN Cell: A non-NTN cell.

[0076] Further information on a number of concepts 4G and 5G and potential equivalents in 6G are set out below: - 4G and 5G RRC connected state - UE having established a connection with a RAN, i.e. a cell, gNB or similar identity. Cell - This may be also be a different concept in a 6G system. For instance in a cellless case a UE may attach, connect and be associated with a beam or other similar identity. RRC idle - UE not in a RRC connected state, i.e. not having established a connection. RRC idle also means that UE will be camping on a cell or similar identity and then performing measurements and evaluating to find a better cell or similar identity. 5G RRC inactive - UE in a state similar to RRC idle where the UE stores the RRC configuration and resumes the RRC connection using the configuration. The network also stores the UE context and uses it to restore the UE connection. 5G RRC procedures (RRC Setup, RRC Resume, RRC Re-establishment, RRC Reconfiguration) - Any procedure that aims to establish a connection with a cell, a gNB or similar identity. For instance a procedure that aims to establish a 5G-6G Dual Connectivity setting with a 5G and 6G cell. Random access - The process of synchronizing the MAC layer via sending a preamble and receiving a message that synchronizes the uplink, as well as following messages to resolve any contention. Radio Link Failure - Failure of the radio link, which may be a failure based on measured radio signals, or based on operation in the cell, such as a number of retransmissions, random access failures, the radio beams failing etc. After the radio link failure the UE may try to reselect to another cell and re-establish the RRC connection. Handover - Performing active mobility to another cell, gNB or similar identity. Releasing RRC connection - The UE is released via a messages such as RRC Release that releases the RRC connection the UE has to one or more cells. This may also include the UE S&F Cell Barring and De-Prioritization

[0077] In some instance it may be beneficial to bar a “legacy” UE from connecting to a non-terrestrial Store and Forward cell. Such a legacy UE may be a UE not capable of performing Store and Forward operation due to not implementing the feature, or a UE choosing not to operate as such a UE. It can be considered known that barring a non-capable S&F UE is done by utilizing a barring operation that is understood by all legacy UEs, for instance in cellBarred in MIB (for 5G NR), cellBarred in SIB1 and SIB-NB (in E-UTRAN, eMTC and NB-loT).

[0078] In an example of the present disclosure, a further condition is added to the possible barring conditions, by making the barring conditioned on whether the UE is able to detect other non-S&F cells. A motivation for this is that S&F cells are expected to deliver a single message (or a limited number of messages) and if there is the possibility to connect to any other cell (i.e. non-S&F cell), then such a cell should be selected. The other non-S&F cells can be other NTN cells, but may also be terrestrial cells. This other non-S&F cell may be within the same frequency, within the same RAT, or within a same PLMN. Whether this barring condition shall be used can be configured by the network but may also be configured by the UE. A number of examples of the condition during which a detected S&F cell (or S&F cells) may be considered barred (where each condition may be taken alone or in any combination) are as follows: UE considers the S&F cell barred if a non-S&F cell has been detected. UE considers the S&F cell barred if a non-S&F cell has been detected and the non-S&F cell is considered a suitable cell. o This may be important as a non-S&F cell shall not only be detected, but it shall also be considered a suitable cell, i.e. it needs to fulfill the suitability requirements which includes whether the cell selection criteria is fulfilled. The cell selection criteria may include determining whether the signal strength and signal quality is good enough according to some configured parameters. o The condition may also include whether the other non-S&F cells are barred or not. In other words, the UE may consider the S&F cell barred if a non-S&F cell has been detected that is a suitable cell and is not barred. UE considers the S&F cell barred if a non-S&F cell has been detected on the same frequency UE considers the S&F cell barred if a non-S&F cell has been detected in the same PLMN UE considers the S&F cell barred if cellBarred-S&F (or other appropriate indicator, field, or information) is set to ‘condition’ (or other appropriate predetermined value) and if a non-S&F cell has been detected o There may be an option to set a value condition in the cellBarred-S&F that indicates that the cell may be considered based on any of the conditions above or other non-specified conditions. This option may be in addition to other values of cellBarred-S&F, i.e. the values barred and notBarred. UE considers the S&F cell barred if a terrestrial cell has been detected in the same PLMN o A cell can be terrestrial if the cell does not broadcast cellBarred-NTN or another appropriate indicator. UE considers a cell broadcasting cellBarred-S&F barred if a cell has been detected that does not broadcast cellBarred-S&F.

[0079] Here and throughout this disclosure, content received from the network providing an indication or information may be referred to as indicators, information, fields, bits, information elements or any other suitable term. Furthermore, such content may be referred to as being included in a signal, information, or message received from the network. The term network may also be considered to include any non-UE entity, such as an eNB, base station, satellite, core network entity, RAN entity etc.

[0080] Figure 4 provides an example method at a UE for determining whether a detected S&F cell is barred.

[0081] In step 402, the UE searches and measures one or more cells as part of a cell selection and / or cell reselection procedure, which may for example be performed when the UE is an idle mode.

[0082] In step 404 the UE detects an S&F cell. If an S&F cell is not detected, the method may end and / or a conventional cell selection / reselection method performed.

[0083] In step 406, the UE determines whether it has detected any other non-S&F cells.

[0084] If one or more non-S&F cells have been detected at step 406, the UE considers the detected S&F cells barred at step 408.

[0085] If no non-S&F cells have been detected at step 406, the UE checks one or more further conditions to see whether the detected S&F cell(s) are barred at step 408.

[0086] Although a primary barring condition of detecting a non-S&F cell is shown in Figure 4, the method is not limited to this and any of the conditions discussed herein may be used. For example, the other non-S&F cells may have to satisfy one or more other conditions in order for the S&F cell(s) to be barred. One or more further steps may also be introduced in the method of Figure 4 and / or steps combined and / or omitted, possible depending on the nature of the barring conditions being implemented.

[0087] If a condition to bar an S&F cell is based on whether there is a terrestrial network detected, the UE may consider the S&F cell to be barred temporarily, i.e. for a limited amount of time. This can for instance be 300 seconds, or may also be any time configured by the UE or network.

[0088] In some examples, even if one or more of the above barring conditions are not fulfilled, the UE may still consider whether the S&F cell is barred to be UE based on other factors, such as whether the S&F cell itself is signaling to be a barred cell, and / or whether the S&F is suitable. In other words, the S&F cell not being barred by the above conditions, does not necessarily mean that the S&F cell still not barred.

[0089] In some examples, an S&F cell may be deprioritized (i.e. as opposed to barred) in idle mode cell selection and / or cell reselection procedures. This deprioritization may operate by deprioritizing a specific S&F cell or the whole or part of the frequency on which an S&F cell is operating on.

[0090] In another example, the deprioritization may be implemented by deprioritizing a frequency if an S&F cell has been detected on the frequency. This means that if a UE detects an S&F cell, the UE considers the frequency to be deprioritized. Another way of expressing this is that a UE capable of S&F considers the frequency to be of the lowest priority if the UE detects an S&F cell on the frequency.

[0091] In another example, the UE may consider whether to deprioritize a S&F cell depending on whether a non-S&F cell has been detected. In other words, the UE may consider an S&F cell to be of the lowest (or lower) priority if the UE is able to detect other non-S&F cells. These non-S&F cells may be cells on the same frequency, on inter-frequencies, inter-RAT frequencies, or within the same PLMN. The non-S&F cells may be other non-terrestrial cells that do not operate S&F, or terrestrial cells. Such an approach can assist in preventing an S&F cell being selected if there ever is a better alternative.

[0092] In another example, the UE may also consider whether to deprioritize a frequency if an S&F cell is detected on the frequency and a non-S&F cell is detected on other intra-RAT frequencies and / or inter-RAT frequencies.

[0093] This deprioritization, i.e. the deprioritization of an S&F cell or a frequency with S&F cells detected, may be active for a certain time, such as 300 seconds or be configurable to any suitable time by the network or UE.

[0094] The prioritization may be specifically configured by the UE and / or the network. This can be a configuration prioritizeNonSF (or any other suitable information or indicator), which is signalled or configured either by the S&F cell, configured by other non-S&F cells, or configured by NAS (higher / upper layers). Examples of this can be: A UE capable of S&F shall consider an S&F cell configured prioritizeNonSF to be of the lowest priority if the UE is able to detect other non-S&F cells on the same frequency, on inter-frequencies or inter-RAT frequencies. o In this case, each S&F cell may need to configure the prioritizeNonSF. This can allow for more flexibility whereby only certain S&F cells uses this mechanism. For instance if there are more capable S&F cells, then this allows for better differentiation. A UE capable of S&F and configured by upper layers to deprioritize S&F shall consider an S&F cell to be of the lowest priority if the UE is able to detect other non-S&F cells on the same frequency, on inter-frequencies or inter-RAT frequencies. A UE capable of S&F shall consider an S&F cell to be of the lowest priority if the UE is able to detect other non-S&F cells on the same frequency, on inter-frequencies or inter-RAT frequencies, if the UE has been configured with prioritizeNonSF (or other suitable indicator or information). o This can be configured with dedicated signalling from the previous cell, or it can be configured with dedicated signalling from a previous non-S&F cell.

[0095] The UE may also be configured to not be required to measure a frequency if the UE detects an S&F cell on a frequency. In this case, if the UE detects an S&F cell on a frequency, then instead of deprioritizing the frequency (or in addition), the UE is configured to not be required to measure the frequency.

[0096] In another example, one or more new parameters to select an S&F network are introduced. This can for instance be an S&F cell-specific: Cell reselection priority T-reselection RAT. For instance the UE would need to fulfill the reselection criteria for an S&F cell-specific amount of time in order to select an S&F cell to camp on. Srxlev (strength level) threshold for S&F measurements

[0097] The above may also apply to inter-RAT cell reselection. For instance if the UE has camped on a 5G NR terrestrial network and performs cell reselection and detects a 4G loT S&F cell, then the above methods may apply. Similarly it may also apply if the UE camps on a 4G network and detects a 5G NR or 6G S&F cell. Furthermore, barring may be considered a specific type of prioritization, such that barring may be considered to fall within the scope of prioritization. More generally, any combination of cell types, frequencies, capabilities may be considered when determining S&F cell barrings and / or priorities. Discontinuous Coverage and S&F Operation

[0098] Discontinuous coverage may be employed together with so-called S&F operation. There may for instance be an instances where some cells are operating as S&F with discontinuous coverage and some cells operate as non-S&F cells but with discontinuous coverage. For example, the non-S&F cells with discontinuous coverage may support legacy Release 17 UEs and S&F capable UEs, while the S&F cells support only S&F capable UEs.

[0099] In one example, the S&F-capable UEs may take into account the S&F cells in the discontinuous coverage operation. For instance, an S&F-capable UE may need to wake up to perform idle mode tasks when an S&F cell approaches. This could be different from legacy UEs, that may not have the ability to gain knowledge about S&F cells. Thus in some examples only S&F-capable UEs acquire S&F information and use the information in the discontinuous coverage operation.

[00100] Taking into account the S&F cells in the discontinuous coverage operation may comprise one or more actions.

[00101] In one example, a UE may determine whether it is in or out-of-coverage based on the coverage provided by S&F cells. In turn, based on such a determination, in some instances the UE may be allowed to not wake up from not performing any idle mode tasks, or be considered out-of-coverage based on the S&F cells (i.e. even if an S&F cell is available, the UE does not wake up). Such an example may occur when a UE has been provided information, such as information on specific satellites that the UE can connect to. This information can be from the upper layers, or from the RAN layers (for instance in an RRC connection release message) comprising satellite information. This satellite information may be satellite!Ds, which indicate the IDs of satellites, which may or may not be S&F satellites (however further information may also be provided such as an indication of whether a satellite is an S&F satellite). This may mean that even though there are satellites or cells, which may or may not be S&F satellites or cells, that pass over the UE, in which the UE may or may not normally be required to wake up to, the UE may not be required to wake up to perform idle mode tasks for these indicated satellites. The information from upper layers may be from MME or AMF or other entity in a NAS message. An example of this can be found in Example E and in Figure 5.

[00102] This may mean that the RAN broadcasts discontinuous coverage-related information, and the upper layers, for instance from MME via NAS, sends information that the UE uses to select certain elements of what RAN broadcasts and determines how to operate discontinuous coverage, i.e. how to determine when the UE shall perform idle mode tasks or to be considered out-of-coverage.

[00103] The idle mode tasks may be only the NTN idle mode tasks, i.e. performing measurements or similar on NTN cells, frequencies and RATs.

[00104] In Figure 5, a UE is signalled that it is to perform idle mode task only during coverage provided by S&F satellites 1 and 6 (Satellite! D=1 &Satellite! D=6), whereas otherwise the UE may also perform idle mode tasks during the coverage provided by S&F satellite 3 (Satellite! D=3). Consequently, by being provided by information on satellite coverage and / or information on satellites to ignore and / or a time range to ignore satellites, the UE may reduce the tasks it performs in idle mode, potentially reducing power consumption. In other words, the idle mode operations of the UE are not only determined by whether there is coverage but also (or alternatively) by the identity / functionality of the satellite that is providing the coverage. Although S&F satellites are considered in Figure 5, one or more of the satellites may non-S&F satellites.

[00105] With respect to signalling (e.g. broadcasting) the S&F-capable satellites, an indication of their identities may be provided in a separate list of satellites or cells, and not in the same list of satellites that provides the discontinuous coverage satellites. Thus the network may signal two lists of discontinuous coverage. One list consists of non-S&F cells or satellites, that are readable by a Release-17 discontinuous coverage-capable UE, and one list of cells or satellites that are readable by a S&F-capable UE, and also potentially discontinuous coverage-capable UEs. This can be seen in Example F. The benefit of this is that a UE that is not S&F-capable and should not connect nor camp on a S&F cell, such a UE will not be able to see the satellite info giving the ephemeris and coverage information of S&F satellites.

[00106] The satellite assistance information on the S&F-capable satellites may also be sent in a dedicated manner. This information and also other information concerning assistance information on S&F satellites may also be termed S&F (satellite) assistance information.

[00107] A list of satellite IDs for S&F satellites may also be provided via RRC connection release message. This can be useful if the core network is unable to send the suitable S&F satellites. It can be provided as part of a redirection message or as a message to just release the UE. This information is then saved by the UE in idle mode and then used to determine how long the UE will not perform any idle mode tasks, or stay out-of-coverage.

[00108] With the information on each satellite, the network may signal the time when the S&F-capable satellite does or does not have ground network or full core network connectivity. This may be provided when the satellite information for S&F satellites is broadcast or as part of RRC Release message. It may additionally or alternatively be useful to provide the information in a dedicated RRC release information. It can for instance be provided for one or two satellite IDs that are expected to pass by the UE earliest. In another example, the broadcast information or the dedicated information in an RRC connection release message may be provided to all UEs, and then the upper layer (for instance via NAS, which is signalling sent transparently from MME to UE) provides the satellite ID that is then used to determine when a UE is to wake up given the traffic requirements etc. Missing S&F Satellite Assistance Information

[00109] If the upper layers, e.g. via NAS signalling, send a message containing one or more satellite IDs that the UE cannot identify as part of broadcasted or other received information, then there may be one or more different actions the UE may take. Such a situation may occur as the UE is about to be released to RRC idle or RRC inactive but is not only limited to these situations.

[00110] In one example, the UE may request satellite information from the network by sending a request with one or more satellite IDs. This request can be sent to the cell (or eNB / gNB), for instance via RRC, upon which the cell (or eNB / gNB) responds with the requested information, i.e. the satellite information. The trigger for this request may be that upper layers have configured or sent UEs satellite IDs for which the UE does not have complete satellite information. It may also be triggered if the UE has no information on any satellite IDs. The condition for requesting the information may thus be that if the UE has received satellite IDs or satellite information from upper layers and the UE does not have the associated satellite assistance information. The network may also or alternatively poll the UE to check if the UE has sufficient information on the satellite!Ds that the UE has been configured with from upper layers, i.e. network sends a request querying whether a UE has satellite assistance information on the satellite!Ds it has been configured with, and the UE replies with the status. This may be important as it can be difficult to ensure that the information sent by the eNB and the MME are synchronized. This approach is illustrated by Figure 6.

[00111] Figure 6 illustrates example signalling between a UE 602, S&F eNB 604 and an MME 606 in accordance with an example of the present disclosure where the UE determines whether it has (or lacks) information on indicated satellites.

[00112] At step 610, the S&F eNB 604 broadcasts satellite assistance information for discontinuous coverage information and information on one or more S&F satellites, which is received by the UE. The satellite assistance information may include any form of information required for the UE to operate with a satellite.

[00113] At step 612, the MME 606 transmits to the UE 602 a NAS message including one or more Satellite! Ds indicating satellites for one or more S&F cells. The indicated satellites may be satellites that the UE is to consider for coverage, to bar, to adapt idle operation based upon etc.

[00114] At step 614, the UE 602 determines whether it lacks information on any of the one or more satellites indicated in the NAS message.

[00115] At step 616, the UE 602 transmits a request to the S&F eNB 604 for information on the one or more satellites (e.g. by including satellite!Ds) that the UE 602 is lacking information on.

[00116] At step 618, the S&F eNB 604 responds to the request by transmitting to the UE 602 information on the satellites indicated in the request. In some examples, only the information that the UE lacks may be transmitted, for instance, if the S&F eNB is aware of specific information the UE lacks (e.g. due to such information being signalled by the UE at step 616).

[00117] At step 620, the UE 602 utilises the satellite information obtained from steps 610 and / or 618 to determine out of coverage information or other parameters / conditions associated with the S&F satellites. For example, the UE may perform any of the operations described by this disclosure based on the satellite information.

[00118] The request (e.g. the request of step 616) may be done through any RRC message, such as UEAssistanceinformation, UElnformationResponse, ULInformationTransfer or sent in an RRC -Complete message (RRC Setup Complete, RRC Connection Resume Complete, RRC Reestablishment Complete, RRC connection reconfiguration complete). The response (e.g. the response of step 618) may be done via RRC Reconfiguration, DLlnformationTransfer or similar. The response may also be sent in an RRC Connection Release message. This can be useful if the UE is about to be released. The response may also be sent in a dedicated system information delivery. The response may also be in the form of updated system information, thus the network will not specifically send dedicated response information, but rather just update the currently broadcasted system information.

[00119] Figure 6 is based upon the UE determining and requesting satellite information that it lacks. However, steps 614-618 may be based on the above described polling implementation. For example, between steps 612 and 614 the network may poll the UE of whether it lack information on any the satellites indicated at step 612. In response the UE may perform step 614 and then in place of 616, send a polling response indicating the information the UE lacks.

[00120] Although specific implementations have been described with reference to Figure 6, the underlying approach of identifying a lack of satellite (assistance) information on indicated satellites at the UE, indicating such a lack of information to the network (e.g. via a poll response or a request), and receiving the required satellite information from the network may be implemented using any suitable procedure.

[00121] In another example, the MME or AMF indicates to the S&F eNB which of the satellite!Ds that were indicated in a NAS message. The S&F eNB can then use this to send the missing satellite assistance information to the UE. The S&F eNB can do this as it is the S&F eNB that potentially broadcasts the S&F satellite assistance information, for instance in SIB32. In an alternative, the S&F eNB may not broadcast any information on S&F satellites, and thus the S&F eNB would send the information on all of the satellitelDs sent from MME or AMF. Sending the missing satellite assistance information can be sent via RRC Reconfiguration, or for instance via RRC Connection Release. This approach is illustrated by Figure 7.

[00122] Figure 7 illustrates example signalling between a UE 702, S&F eNB 704 and an MME 706 in accordance with an example of the present disclosure where the S&F eNB determines satellite information the UE is lacking and transmits such information to the UE.

[00123] At step 710, the S&F eNB 704 broadcasts satellite assistance information for discontinuous coverage information and information on one or more S&F satellites, which is received by the UE. The satellite assistance information may include any form of information required for the UE to operate with a satellite.

[00124] At step 712, the MME 706 transmits to the UE 702 a NAS message including one or more SatellitelDs indicating satellites for one or more S&F cells. The indicated satellites may be satellites that the UE is to consider for coverage, to bar, to adapt idle operation based upon etc.

[00125] At step 714, the MME transmits to the S&F eNB an indication of the satellites indicated to the UE 702 in step 712 (i.e. the satellitelDs for S&F cells transmitted to the UE 702).

[00126] At step 716, the S7F eNB 704 determines whether the UE 702 lacks information on any of the one or more satellites indicated in the NAS message. This determining step may be based on the information broadcast in step 710 or other information indicating what information has previously been provided to the UE from any network entity.

[00127] At step 718, the S&F eNB 704 transmits to the UE 702 information on the satellites that it has been determined that the UE 702 lacks information on.

[00128] At step 720, the UE 702 utilises the satellite information obtained from steps 710 and / or 718 to determine out of coverage information or other parameters / conditions associated with the S&F satellites. For example, the UE may perform any of the operations described by this disclosure based on the satellite information.

[00129] The indication from MME or AMF on the satellitelDs that were indicated for S&F cells can be sent in a message that releases the UE. For instance UE context suspend, UE context release or similar.

[00130] In another example similar to that illustrated in Figure 7, the MME sends the full satellite assistance information to S&F eNB, which is then delivered to the UE, i.e. sent from the S&F eNB to the UE. Thus the MME first sends the satellite!Ds to UE, and then sends the full satellite assistance information to the S&F eNB, which then delivers this to the UE, for instance in an RRC release message.

[00131] In another example, the UE may assume that the satellite is upcoming and will thus try to acquire more system information from a cell, either from the current satellite it is connected or camping on, or on cells associated with upcoming satellite passes. Other Idle Mode Operations

[00132] In another example, the UE shall not camp or shall deprioritize an S&F cell in case of emergency situations or other high priority situations. This may be important as the S&F cell may for instance not be able to serve a UE adequately during emergency situations, because the S&F cell does not have any ground connectivity. In these situations the UE shall prioritize any other type of cell, for instance an NTN cell with worse signal quality or cell or frequency priority. Such deprioritization may also be manually configured (i.e. turned and off) at the UE.

[00133] In another example, a UE shall consider an S&F cell to not support any emergency services. An example of this can be that if a cell indicates that it is an S&F cell, the UE assumes that IMS emergency services are not supported.

[00134] The above may for instance be achieved if the UE does not consider to camp on an S&F cell if the S&F cell is an acceptable cell.

[00135] In another example, an S&F cell or network shall indicate that it does not support IMS emergency services. This can for instance be done by not setting the IMS emergencysupport bit (i.e. indicator) in system information such as SIB1. This means that an S&F cell may not include or set the ims-EmergencySupport. An S&F cell may also be required to indicate that it does not support eCell over IMS in a similar manner.

[00136] In another example, if an S&F cell have some type of signaling to indicate when it has ground connectivity or full core network connectivity, the UE may use this information to compute whether the S&F cell supports IMS emergency services.

[00137] If for instance the S&F cell indicates via a single bit that it does not have ground connectivity or full core network connectivity, the UE will use this to consider the cell to not support IMS emergency services. And when the single bit indicates that ground connectivity or full network connectivity is restored, the UE considers the cell to support IMS emergency services.

[00138] In another example, if the S&F cell broadcasted more advanced information, such as time when cell has or does not have ground connectivity or full core network connectivity, the UE uses this time to determine when the cell supports IMS emergency services. If similarly any assistance information such as geometrical information is provided to determine whether the S&F cell has ground connectivity or full core network connectivity, the UE uses this information to do the determination.

[00139] The broadcast of the S&F barring bit may also be used. For instance if the barring bit is set with notBarred, the UE may still consider the IMS emergency services to not be supported, if the presence of the barring bit is used to indicate the S&F cell, or if the S&F cell has ground connectivity or full core network connectivity.

[00140] If the UE initiates a call, for instance an IMS call, the UE shall not camp on an S&F cell, and if a call is initiated, then UE shall reselect to a non-S&F cell. Example 3GPP Specification Modification

[00141] In view of the examples set out above, the following provides example additions / adaptations that may be introduced into the 3GPP specification, where the highlighted parts represent some of the additions / adaptations. Example A -----------------36.331 Example----------------- - SystemlnformationBlockTypel SystemlnformationBlockType 1 contains information relevant when evaluating if a UE is allowed to access a cell and defines the scheduling of other system information. SystemlnformationBlockType 1-BR uses the same structure as SystemlnformationBlockType!. Signalling radio bearer: N / A RLC-SAP: TM Logical channels: BCCH and BR-BCCH Direction: E-UTRAN to UE SystemlnformationBlockTypel message — ASN1START SystemInformationBlockTypel-BR-rl3 ::= SystemlnformationBlockTypel SystemlnformationBlockTypel ::= SEQUENCE { cellAccessRelatedlnfo SEQUENCE { p1mn-Identit yL1st trackingAreaCode cellldentity cellBarred intraFreqReselection csg-Indication csg-Identity b cellSelectioninfo q-RxLevMin q-RxLevMinOffset b p-Max Need OP freqBandlndicator schedulinglnfoList tdd-Config si-WindowLength PLMN-IdentityList, TrackingAreaCode, Cellldentity, ENUMERATED {barred, notBarred}, ENUMERATED {allowed, notAllowed}, BOOLEAN, CSG-Identity OPTIONAL SEQUENCE { Q-RxLevMin, INTEGER (1..8) -- Need OR OPTIONAL — Need OP P-Max OPTIONAL, systemlnfoValueTag nonCriticalExtension FreqBandlndicator, SchedulinglnfoList, TDD-Config OPTIONAL, ENUMERATED { msl, ms2, ms5, mslO, msl5, ms20, ms40}, INTEGER (0..31), SystemlnformationBlockTypel-v8 90-IEs — Cond TDD OPTIONAL SystemInformationBlockTypel-vl700-IEs ::= cellAccessRelatedlnfo-NTN-rl7 cellBarred-NTN-rl7 plmn-IdentityList-vl7 0 0 Need OR } OPTIONAL, — Need OR nonCriticalExtension } SEQUENCE { SEQUENCE { ENUMERATED {barred, notBarred}, PLMN-IdentityList-vl700 OPTIONAL SystemlnformationBlockTypel-vl8 0 0-IEs OPTIONAL SystemlnformationBlockTypel-vl8 0 0-IEs freqBandlndicatorAerial-rl8 OR freqBandlnfoAerial-rl8 OR multiBandlnfoListAerial-rl8 OR nonCriticalExtension SEQUENCE { FreqBandlndicator-rll OPTIONAL, -- Need NS-PmaxListAerial-rl8 OPTIONAL, — Need MultiBandInfoListAerial-rl8 OPTIONAL, -- Need SystemlnformationBlockTypel-vl900-IEs OPTIONAL 3Q t—mlnf imati nEl ; OPTIONAL — ASN1STOP SystemlnformationBlockTypel field descriptions I bandwiihReducedAccessReiaiedinfo i Access related information for BL UEs and UEs in CE. NOTE 3. I cam pingAllowedlnCE i Indicates whether non-BL UE is allowed to camp in the non-standalone BL cell in enhanced coverage mode when S- I criterion for normal coverage is fulfilled. The field is not applicable for standalone BL cell. i caiegoryOAIIowed I The presence of this field indicates category 0 UEs are allowed to access the cell. i ceilAccessReiaiedinfoList I This field contains a list allowing signalling of access related information per PLMN. One PLMN can be included in i only one entry of this list. NOTE 4. I cellAccessRelatedlnfoList-5GC I This field contains a PLMN list and a list allowing signalling of access related information per PLMN for PLMNs that i provides connectivity to 5GC. One PLMN can be included in only one entry of this list. NOTE4 i ceUBarred, ceilBarred-CRS i barred means the cell is barred, as defined in TS 36.304 [4], i ceiiBarred-5GC, ceiiBarred-5GC-CRS i barred means the cell is barred for connectivity to 5GC, as defined in TS 36.304 [4], ceUBarred-NfN................................................................................................................................................................................................................... I barred means the cell is barred for connectivity to NTN, as defined in TS 36.304 [4], I E-UTRAN always includes cellBarred-NTN and sets ceUBarred to 'barred' in an NTN cell. i cellBarred-SF i cellldentiiy ( Indica^ cell identity. N OTE 2. i cellld-lndex I The index of the cell ID in the PLMN lists for EPC, indicates UE the corresponding cell ID is used for 5GC. Value 1 i indicates the cell ID of the 1st PLMN list for EPC in the SIB1. Value 2 indicates the cell ID of the 2nd PLMN list for I EPC, and so on. -----------------36.331 Example----------------- Example B -----------------36.304 Example----------------- 5.3.1 Cell status and cell reservations Cell status and cell reservations are indicated in the SystemlnformationBlockType 1 message (or SystemlnformationBlockTypel-BR message or SystemlnformationBlockType 1-NB message) TS 36.331 [3] by means of the following fields: ceUBarred (IE type: "barred" or "not barred") This field indicates if the cell is barred for connectivity to EPC. This field is ignored by the UEs supporting crs-IntfMitig while crs-IntJMitigEnabled is included in SIB1. This field is ignored by the BL UEs or UEs in CE supporting ce-CRS-IntfMitig while crs-IntfMigitNumPRBs is included in SIB1-BR. This field is ignored by UEs supporting NTN while cellBarred-NTN is included in SIB1-BR or SIB1-NB. In case of multiple EPC PLMNs indicated in SIB1 / SIB1-BR, this field is common for all EPC PLMNs NOTE 1: IAB-MT ignores the ceUBarred, cellReservedForOperatorUse, intraFreqReselection and csg-Indication (i.e. treats intraFreqReselection as if it was set to allowed and the csg-Indication as if it was set to FALSE) as defined in TS 36.331 [3], - cellBarred-5GC (IE type: "barred" or "not barred") This field indicates if the cell is barred for connectivity to 5GC. This field is ignored if the UE does not support E-UTRA connected to 5GC or if the UE supports network-based CRS interference mitigation and nw-BasedCRS-InterferenceMitigation is included in SystemlnformationBlockType 1. In case of multiple 5GC PLMNs indicated in SIB1, this field is common for all 5GC PLMNs. cellReservedForOperatorUse (IE type: "reserved" or "not reserved") This field indicates if the cell is reserved for operator use. This field is ignored by the UEs supporting crs-IntfMitig while crs-IntJMitigEnabled is included in SIB1. This field is ignored by the BL UEs or UEs in CE supporting ce-CRS-IntjMitig while crs-IntfMigitNumPRBs is included in SIB1-BR. In case of multiple EPC or 5GC PLMNs indicated in SIB1 / SIB1-BR, this field is specified per EPC or 5GC PLMN. - cellBarred-CRS (IE type: "barred" or "not barred") This field indicates if the cell is barred for connectivity to EPC for UEs supporting network-based CRS interference mitigation. barred means the cell is barred for UEs supporting crs-IntfMitig while crs-IntfMitigEnabled is included in SIB1. For BL UEs or UEs in CE capable of ce-CRS-IntjMitig, barred means the cell is barred while crs-IntflditigNumPRBs is included in SIB 1 -BR. This field is ignored by the UE if the UE does not support CRS interference mitigation or while crs-IntfMitigConfig is not included in SIB1 (SIB1-BR for BL UEs or UEs in CE). In case of multiple PLMNs indicated in SIB1 / SIB1-BR, this field is common for all PLMNs. cellBarred-5GC-CRS (IE type: "barred" or "not barred") This field indicates if the cell is barred for connectivity to 5GC for UEs supporting network-based CRS interference mitigation. This field is ignored if the UE does not support E-UTRA connected to 5GC or network-based CRS interference mitigation. In case of multiple 5GC PLMNs indicated in SIB1, this field is common for all 5GC PLMNs. cellReservedForOperatorUse-CRS (IE type: "reserved" or "not reserved") This field indicates if the cell is reserved for operator use for UEs supporting network-based CRS interference mitigation. reserved means the cell is "reserved" for operator use for UEs supporting crs-IntfMitig while crs-IntjMitigEnabled is included in SIB 1. For BL UEs or UEs in CE capable of ce-CRS-IntjMitig, reserved means the cell is "reserved" for operator use while crs-IntfKditigNumPRBs is included in SIB1-BR. This field is ignored if the UE does not support CRS interference mitigation or while crs-IntfMitigConfig is not included in SIB1 (SIB1-BR for BL UEs or UEs in CE). In case of multiple PLMNs indicated in SIB1 / SIB1-BR, this field is specified per PLMN. iab-Support (IE type: "true") Indicated in SIB1 message. In case of multiple PLMNs indicated in SIB1, this field is specified per PLMN. This field indicates if the cell is barred for IAB node or the cell does not support IAB node, or both. When this field is absent, the IAB node shall treat this cell as if cell status is barred. - cellBarred-NTN (IE type: "barred" or "not barred") This field indicates if the cell is barred for connectivity to EPC via NTN. This field is ignored if the UE does not support NTN connectivity. The following description for handling of barred and reserved cells is per CN type. If the UE supports more than one CN type, the UE shall only exclude a cell as candidate for selection / reselection if it is excluded for both CN types. NOTE 2: Fields cellBarred-CRS and cellReservedForOperatorUse-CRS are not indicated in SystemlnformationBlockType 1-NB When cell status is indicated as "not barred" and "not reserved" for operator use, -else: All UEs shall treat this cell as candidate during the cell selection and cell reselection procedures. When cell status is indicated as "not barred" and "reserved" for operator use for any PLMN, UEs assigned to Access Class 11 or 15 (or corresponding Access Identity) operating in their HPLMN / EHPLMN shall treat this cell as candidate during the cell selection and reselection procedures if the field cellReservedForOperatorUse for that PLMN set to "reserved". UEs assigned to an Access Class in the range of 0 to 9 (or corresponding Access Identity 0), 12 to 14 (or corresponding Access Identity) or to Access Identity 1, 2 or 3 shall behave as if the cell status is "barred" in case the cell is "reserved for operator use" for the registered PLMN or the selected PLMN. NOTE 3: ACs 11, 15 (or corresponding Access Identity) are only valid for use in the HPLMN / EHPLMN; ACs 12, 13, 14 (or corresponding Access Identity) are only valid for use in the home country TS 22.011 [4], NOTE 4: Access Identities 1, 2 are valid in the PLMNs as specified in TS 22.261

[41] , NOTE 5: Access Identity 3 is only valid for PLMNs that indicate to potential Disaster Inbound Roamers that the UEs can access the PLMN as specified in TS 22.261

[41] , When cell status "barred" is indicated or to be treated as if the cell status is "barred", The UE is not permitted to select / reselect this cell, not even for emergency calls. The UE shall consider other cells for cell selection / reselection according to the following rule: If the cell is to be treated as if the cell status is "barred" due to the cell being an S&F cell and a non-S&F cell is detected, or; If the cell is to be treated as if the cell status is "barred" due to being unable to acquire the MasterlnformationBlock (or MasterlnformationBlock-NB), the SystemlnformationBlockType 1 (or SystemlnformationBlockType 1-BR message or SystemlnformationBlockType 1-NB), the SystemlnformationBlockType2 (or SystemInformationBlockType2-NB) or SystemlnformationBlockType31 (or SystemlnformationBlockType31-NB) if broadcasted for UEs supporting NTN: the UE may exclude the barred cell as a candidate for cell selection / reselection for up to 300 seconds. the UE may select another cell on the same frequency if the selection criteria are fulfilled. the UE may select the same cell in normal coverage if the UE was barred in the cell due to being unable to acquire MasterlnformationBlock, SystemlnformationBlockType 1-BR, or SystemlnformationBlockType2 in enhanced coverage, but was able to acquire MasterlnformationBlock, SystemlnformationBlockType!, and SystemInformationBlockType2 in normal coverage, if the selection criteria are fulfilled. the UE may select the same cell in enhanced coverage if the UE was barred in the cell due to being unable to acquire MasterlnformationBlock, SystemlnformationBlockType!, or SystemlnformationBlockType2 in normal coverage, but was able to acquire MasterlnformationBlock, SystemlnformationBlockType 1-BR, and SystemInformationBlockType2, if the selection criteria are fulfilled. else If the cell is a CSG cell: - the UE may select another cell on the same frequency if the selection / reselection criteria are fulfilled. else If the field intraFreqReselection in field cellAccessRelatedlnfo in SystemlnformationBlockType! (or SystemlnformationBlockType 1-BR message or SystemlnformationBlockType 1-NB) message is set to "allowed", the UE may select another cell on the same frequency if re-selection criteria are fulfilled. The UE shall exclude the barred cell as a candidate for cell selection / reselection for 300 seconds. If the field intraFreqReselection in field cellAccessRelatedlnfo in SystemlnformationBlockTypel (or SystemlnformationBlockType 1-BR message or SystemlnformationBlockType 1-NB) message is set to "not allowed" the UE shall not re-select a cell on the same frequency as the barred cell; The UE shall exclude the barred cell and the cells on the same frequency as a candidate for cell selection / reselection for 300 seconds. The cell selection of another cell may also include a change of RAT or, if the previous and selected cell are both E-UTRA cells, a change of the CN type. -----------------36.304 Example----------------- Example C 36.331 Example SystemlnformationBlockTypel message — ASN1START Systemlnf ormationBlockTypel-BR-rl.3 SystemlnformationBlockTypel SystemlnformationBlockTypel ::= cellAccessRelatedlnfo p1mn-Identit yL i s t trackingAreaCode cellldentity cellBarred intraFreqReselection csg-Indication csg-Identity b cellSelectioninfo q-RxLevMin q-RxLevMinOffset b p-Max Need OP freqBandlndicator schedulinglnfoList tdd-Config si-WindowLength SEQUENCE { SEQUENCE { PLMN-IdentityList, TrackingAreaCode, Cellldentity, ENUMERATED {barred, notBarred}, ENUMERATED {allowed, notAllowed}, BOOLEAN, CSG-Identity OPTIONAL SEQUENCE { Q-RxLevMin, INTEGER (1..8) OPTIONAL P-Max OPTIONAL, -- Need OR -- Need OP systemlnfoValueTag nonCriticalExtension FreqBandlndicator, SchedulinglnfoList, TDD-Config OPTIONAL, ENUMERATED { msl, ms2, ms5, mslO, msl5, ms20, ms40}, INTEGER (0..31), SystemlnformationBlockTypel-v8 90-IEs — Cond TDD OPTIONAL -- Regular non critical extensions SystemlnformationBlockTypel ims-EmergencySupport-r9 cellSelectioninfo-v920 •v920-IEs ::= SEQUENCE { ENUMERATED {true} CellSelectioninfo-v920 OPTIONAL, OPTIONAL, nonCriticalExtension SystemlnformationBlockTypel-vl130-IEs -- Need OR — Cond RSRQ OPTIONAL _. OMITTED ._ — ASN1STOP SystemlnformationBlockTypel field descriptions [...............................................................................................................OMITTED................................................................................................................] i ims-EmergencySupport I Indicates whether the cell supports IMS emergency bearer services via EPC for UEs in limited service mode. If I i absent, IMS emergency call via EPC is not supported by the network in the cell for UEs in limited service mode. NOTE i i 2. i ims-EmergencySupportSGC I Indicates whether the cell supports IMS emergency bearer services for UEs in limited service mode via 5GC. If I I absent, IMS emergency call via 5GC is not supported by the network in the cell for UEs in limited service mode. NOTE I ; 2. An S&F cell does not indicate support ims-EmergencySupport. i -----------------36.331 Example----------------- Example D -----------------36.304 Example----------------- 5.2.4.1 Reselection priorities handling Absolute priorities of different E-UTRAN frequencies or inter-RAT frequencies may be provided to the UE in the system information, in the RRCConnectionRelease or RRCEarlyDataComplete message, or by inheriting from another RAT at inter-RAT cell (re)selection. In the case of system information, an E-UTRAN frequency or inter-RAT frequency may be listed without providing a priority (i.e. the field cellReselectionPriority is absent for that frequency). If priorities are provided in dedicated signalling, the UE shall ignore all the priorities provided in system information. If UE is in camped on any cell state, UE shall only apply the priorities (i.e. cellReselectionPriority and / or cellReselectionSubPriority) provided by system information from current cell, and the UE preserves priorities provided by dedicated signalling, deprioritisationReq received in RRCConnectionReject and altFreqPriorities provided by dedicated signalling unless specified otherwise. When the UE in camped normally state, has only dedicated priorities other than for the current frequency, the UE shall consider the current frequency to be the lowest priority frequency (i.e. lower than any of the network configured values). While the UE is camped on a suitable CSG cell in normal coverage, the UE shall always consider the current frequency to be the highest priority frequency (i.e. higher than any of the network configured values), irrespective of any other priority value allocated to this frequency. When the HSDN capable UE is in High-mobility state, the UE shall always consider the HSDN cells to be the highest priority (i.e. higher than any other network configured priorities). When the HSDN capable UE is not in High-mobility state, the UE shall always consider HSDN cells to be the lowest priority (i.e. lower than network configured priorities). If the UE capable of sidelink communication is configured to perform sidelink communication and can only perform the sidelink communication while camping on a frequency, the UE may consider that frequency to be the highest priority. If the UE capable of V2X sidelink communication is configured to perform V2X sidelink communication and can only perform the V2X sidelink communication while camping on a frequency, the UE may consider that frequency to be the highest priority. If the UE capable of V2X sidelink communication is configured to perform V2X sidelink communication and can only use pre-configuration while not camping on a frequency, the UE may consider the frequency providing intercarrier V2X sidelink configuration to be the highest priority. If the UE is configured to perform both V2X sidelink communication and NR sidelink communication, the UE may consider the frequency providing both V2X sidelink communication and NR sidelink communication configuration to be the highest priority.If the UE is configured to perform V2X sidelink communication and not perform NR sidelink communication, the UE may consider the frequency providing V2X sidelink communication configuration to be the highest priority. If the UE is configured to perform NR sidelink communication and not perform V2X sidelink communication, the UE may consider the frequency providing NR sidelink communication configuration to be the highest priority. If the UE capable of sidelink discovery is configured to perform Public Safety related sidelink discovery and can only perform the Public Safety related sidelink discovery while camping on a frequency, the UE may consider that frequency to be the highest priority. A UE on a vehicle with an NR mobile-IAB cell detected may consider the inter-RAT frequency for which an NR mobile-IAB cell is the best cell to be the highest priority. The UE identifies an NR mobile-IAB cell by mobilelAB-Cell in SIB1 (see TS 38.331

[37] ). The UE may narrow its search scope for NR mobile-IAB cell(s) by mobilelAB-CellList if broadcasted in SystemInformationBlockType24 (see TS 36.331 [3]). A non-mobile-IAB cell may be excluded from this mobile IAB frequency prioritization for up to 300 seconds. NOTE 1: The prioritization among the frequencies which UE considers to be the highest priority frequency is left to UE implementation. NOTE 1 a: The frequency only providing the anchor frequency configuration should not be prioritized for V2X service during cell reselection as specified in TS 36.331 [3], NOTE lb: When UE is configured to perform NR sidelink communication or V2X sidelink communication performs cell reselection, it may consider the frequencies providing the intracarrier and inter-carrier configuration have equal priority in cell reselection. NOTE 1c: The UE is configured to perform V2X sidelink communication or NR sidelink communication, if it has the capability and is authorized for the corresponding sidelink operation. NOTE Id: When UE is configured to perform both NR sidelink communication and V2X sidelink communication, but cannot find a frequency which can provide both NR sidelink communication configuration and V2X sidelink communication configuration, UE may consider the frequency providing either NR sidelink communication configuration or V2X sidelink communication configuration to be the highest priority. NOTE le: How the UE determines itself to be on a vehicle with an NR mobile-IAB cell is left to UE implementation. -----------------36.304 Example----------------- Example E -----------------36.304 Example - 4 General description of Idle mode 4.1 Overview ... OMITTED ... If SystemInformationBlockType32 has been received and if the UE has determined that it is out of coverage using available satellite assistance information (e.g. ephemeris parameters and coverage parameters in current or previously received SystemInformationBlockType32, SystemInformationBlockType31, t-Service in SystemInformationBlockType3 or other parameters), the AS configuration (e.g. priorities provided by dedicated signalling and logged measurements) is kept, but the UE need not perform any idle mode tasks related to NTN. It is up to UE implementation to handle running timers. The detection of out of coverage using satellite assistance information is up to UE implementation and once in NTN coverage the UE shall perform all idle mode tasks related to NTN. If SystemlnformationBlockType32 includes carrierFreqList the UE may store and use this information for the cell selection process when UE resumes the idle mode tasks related to NTN once in NTN coverage. A UE supporting S&F shall apply the S&F assistance information (for instance via sAndF-SatellitelnfoList in SyslemhiformationBlockType32 and / or a list of satellitelds from upper layers) to determine whether UE is out-of-eoverage: -----------------36.304 Example----------------- Example F 36.304 Example - SystemlnformationBlockType32 The IE SystemInformationBlockType32 contains satellite assistance information for prediction of discontinuous coverage. SystemlnformationBlockType32 is only signalled in a NTN cell. SystemlnformationBlockType32 information element — ASN1START Systemlnf ormationBlockType.32-rl7 satelliteInfoList-rl7 lateNonCriticalExtension SEQUENCE { SatelliteInfoList-rl7 OPTIONAL, — Need OR OCTET STRING OPTIONAL, [[ satellitelnfoList-vlSOO SatellitelnfoList-vlSOO OPTIONAL -- Need OR J ] 1 [[ saf-Sat-ellitelnfX'List-vlPRO SAF-Sat-ellitelnfX'List-vlPRO OPTIONAL — Na-ed OR SatelliteInfoList-rl7 ::= SatellitelnfoList-vl800 SEQUENCE (SIZE (1..maxSat-rl7)) OF Satellitelnfo-rl7 SEQUENCE (SIZE (1..maxSat-rl7)) OF CarrierFreqList-vl800 SAF-Sat^llitelnfX'List-vlFOO = SEQUENCE (SIZ.E (1 .iitaxSat-rl"? 1 ) OF 3AF-3atellit^Trifo-vlPOO Satellitelnfo-rl7 ::= SEQUENCE { satelliteld-rl7 servicelnfo-rl7 INTEGER (0..255), SEQUENCE { OR tle-EphemerisParameters-rl7 TLE-EphemerisParameters-rl7 OPTIONAL, -- Need OR t-ServiceStart-rl7 TimeOffsetUTC-r!7 OPTIONAL — Need footprintlnfo-rl7 referencePolnt-rl7 longitude-rl7 latitude-rl7 } OPTIONAL, — Need OR elevationAngles-rl7 SEQUENCE { SEQUENCE { INTEGER (-131072..131071), INTEGER (-131072..131071) SEQUENCE { elevationAngleRight-rl7 elevationAngleLeft-rl7 } OPTIONAL, — Need OR radius-rl7 INTEGER INTEGER INTEGER (-14..14), (-14..14) (1. .256) OPTIONAL — Need OP OPTIONAL — Need OR SatellitdIOfO-Vl?OU t: SEQUENCE { sat-ellit-elnfo—rl& Sat-ellit-elnfo—rl7 asaiatanc-eCarri-erlnfm-rl P SEQUENCE fSIEE f 1 .iita::Sat-rl"' 1 5 OF CarrierFreqLi-at-vlROU CarrierFreqList-vl800 ::= SEQUENCE (SIZE (1..maxFreq)) OF ARFCN-ValueEUTRA — ASN1STOP SystemlnformationBlockType32 field descriptions i saf-SatellitelnfoList I satellitelnfoList i List of satellite information. If E-UTRAN includes satellitelnfoList-v1800, it includes the same number of entries, and I listed in the same order, as in satellitelnfoList-r17. -----------------36.304 Example-----------------

[00142] Figure 8 is a block diagram of an exemplary network entity / function that may be used in examples of the present disclosure, such as the techniques disclosed in relation to any of the preceding figures. For example, any of the network entities, network function etc. (e.g. UE, BS, gNB / eNB, ATG entities) may be provided in the form of the network entity illustrated in Figure 8. The skilled person will appreciate that a network entity / function may be implemented, for example, as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, and / or as a virtualised function instantiated on an appropriate platform, e.g. on a cloud infrastructure.

[00143] The entity 800 comprises a processor (or controller) 801, a transmitter 803 and a receiver 805. The receiver 805 is configured for receiving one or more messages from one or more other network entities, for example as described above. The transmitter 803 is configured for transmitting one or more messages to one or more other network entities, for example as described above. The processor 801 is configured for performing one or more operations, for example according to the operations as described above.

[00144] It will be appreciated that, in each example / embodiment / aspect etc. described above, one or more features or operations may be omitted, modified or moved (e.g., to change the order of the features or the operations), if desired and appropriate.

[00145] Additionally, where the figures illustrating example method flows include text in relation to a specific step / operation, it will be appreciated that this text is simply an example of the corresponding step / operation, where a more general definition (such as may be found in the description of the corresponding step) may apply for the step / operation.

[00146] Additionally, regarding all of the above, one or more features or operations etc. from any example / embodiment may be combined with features or operations from any other example / embodiment. That is, the present disclosure should be considered to include all combinations of examples / embodiments disclosed herein, as appropriate, as well as combinations of individual features within and between each example / embodiment, as appropriate.

[00147] The techniques described herein may be implemented using any suitably configured apparatus and / or system. Such an apparatus and / or system may be configured to perform a method according to any aspect, embodiment or example disclosed herein. Such an apparatus may comprise one or more elements, for example one or more of receivers, transmitters, transceivers, processors, controllers, modules, units, and the like, each element configured to perform one or more corresponding processes, operations and / or method steps for implementing the techniques described herein. For example, an operation / function of X may be performed by a module configured to perform X (or an X-module). The one or more elements may be implemented in the form of hardware, software, or any combination of hardware and software.

[00148] It will be appreciated that examples of the present disclosure may be implemented in the form of hardware, software or any combination of hardware and software. Any such software may be stored in the form of volatile or non-volatile storage, for example a storage device like a ROM, whether erasable or rewritable or not, or in the form of memory such as, for example, RAM, memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a CD, DVD, magnetic disk or magnetic tape or the like.

[00149] It will be appreciated that the storage devices and storage media are embodiments of machine-readable storage that are suitable for storing a program or programs comprising instructions that, when executed, implement certain examples of the present disclosure. Accordingly, certain examples provide a program comprising code for implementing a method, apparatus or system according to any example, embodiment and / or aspect disclosed herein, and / or a machine-readable storage storing such a program. Still further, such programs may be conveyed electronically via any medium, for example a communication signal carried over a wired or wireless connection.

[00150] While the disclosure has been shown and described with reference to certain examples, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the disclosure.

[00151] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[00152] Further examples in accordance with the present disclosure are set out in the following first set of numbered clauses, where these may be combined with any of the other examples, implementations, and clauses of this disclosure. 1. A method of a user equipment (UE) for operating in a wireless communications network, the wireless communications network including one or more non-terrestrial network (NTN) store and forward (S&F) cells and one or more non-S&F cells, the method comprising: detecting one or more cells; and if an S&F cell and a non-S&F cell are detected, adjusting a selection priority of the detected S&F cell relative to the non-S&F cell, and performing cell selection based on the adjusted selection priority. 2. The method of clause 1, wherein adjusting a selection priority of the detected S&F cell relative to the non-S&F cell includes barring the S&F cell from being selected if the S&F cell is indicated by the network as being barred. 3. The method of clauses 1 or 2, wherein adjusting a selection priority of the detected S&F cell relative to the non-S&F cell includes barring the S&F cell from being selected if the detected S&F cell and non-S&F cell are within same a same frequency, within a same radio access technology (RAT), and / or with a same public land mobile network (PLMN). 4. The method of any of clauses 1 to 3, wherein adjusting a selection priority of the detected S&F cell relative to the non-S&F cell includes barring the S&F cell from being selected if the non-S&F cell is a suitable cell. 5. The method of clause 1, wherein adjusting a selection priority of the detected S&F cell relative to the non-S&F cell includes reducing the selection priority of the S&F cell. 6. The method of clause 5, wherein reducing the selection priority includes reducing the S&F cell to a lowest selection priority. 7. The method of any preceding clause, wherein the adjusting a selection priority of the detected S&F cell relative to the non-S&F is based on one or more characteristics of the non-S&F cell. 8. The method of any preceding clause, wherein the adjusting a selection priority of the detected S&F cell relative to the non-S&F is based on a UE and / or a network configuration. 9. The method of any preceding clause, wherein the adjusting a selection priority of the detected S&F cell relative to the non-S&F is based on an indicator received from the S&F cell and / or a configuration received from the network. 10. The method of any preceding clause, wherein, if the non-S&F is barred, selecting the S&F cell (i.e. adjusting the S&F cell to have a higher priority than the non-S&F cell). 11. The method of any preceding clause, wherein, if an S&F cell is detected and a non-S&F cell is not detected, performing cell selection based on the detected S&F cell. 12. A user equipment (UE) for operating in a wireless communications network, the wireless communications network including one or more non-terrestrial network (NTN) store and forward (S&F) cells and one or more non-S&F cells, wherein the UE is configured to perform the method of any preceding clause.

[00153] Further examples in accordance with the present disclosure are set out in the following second set of numbered clauses, where these may be combined with any of the other examples, implementations, and clauses of this disclosure. 1. A method of a user equipment (UE) for operating in a wireless communications network, the wireless communications network including a plurality of non-terrestrial network (NTN) cells provided by a respective plurality of satellites, and wherein each of the NTN cells provides discontinuous coverage to the UE, the method comprising: performing an idle mode task within the coverage of only a subset of the plurality of satellites. 2. The method of clause 1, further comprising, receiving from the network, an indication of the subset of satellites. 3. The method of clause 2, wherein the indication includes an identifier (e.g. satellite! D) of each satellite of the subset of satellites. 4. The method of clauses 2 or 3, wherein the indication provides an indication of the satellites not included in the subset of satellites. 5. The method of any of clauses 2 to 4, wherein the indication includes a list indicating satellites of the plurality of satellites included in the subset and / or a list indicating satellites of the plurality of satellites not included in the subset. 6. The method of any of clauses 2 to 5, wherein the indication of the subset of satellites is received through higher layer messaging (e.g. a NAS message). 7. The method of any preceding clause, wherein the method further comprises receiving coverage-related information on the subset of satellites from the network. 8. The method of clause 7, wherein the coverage-related information is received through broadcast information from the network. 9. The method of clause 8, wherein the method further comprises determining the coverage timings of the subset of satellites based on the coverage-related information, and performing the idle mode task based on the determined coverage timings. 10. The method of any preceding clause, wherein at least one satellite of the satellites not included in the subset is a Store and Forward (S&F) satellite. 11. The method of any preceding clause, wherein all the satellites from the plurality of satellites not included in the subset are S&F satellites. 12. The method of any preceding clause, wherein all the satellites from the subset are non- S&F satellites. 13. The method of any preceding clause, wherein the idle mode task includes one or more NTN idle mode tasks. 14. The method of any preceding clause, wherein the UE enters a reduced power mode (i.e. is in a sleep mode, in a discontinuous coverage mode, on deemed to be in discontinuous coverage) outside of the coverage of the subset of satellites. 15. A user equipment (UE) for operating in a wireless communications network, the wireless communications network including a plurality of non-terrestrial network (NTN) cells provided by a respective plurality of satellites, and wherein each of the NTN cells provides discontinuous coverage to the UE, wherein the UE is configured to perform the method of any preceding clause.

[00154] Further examples in accordance with the present disclosure are set out in the following third set of numbered clauses, where these may be combined with any of the other examples, implementations, and clauses of this disclosure. 1. A method of a user equipment (UE) for operating in a wireless communications network, the wireless communications network including one or more non-terrestrial network (NTN) store and forward (S&F) cells providing discontinuous coverage, the method comprising: receiving an indication of one or more satellites providing the NTN cells; if the UE lacks sufficient satellite assistance information on one or more of the indicated satellites, receiving from the network the satellite assistance information on the one or more of the indicated satellites the UE lacks; and performing an idle mode and / or an inactive mode operation based on the received satellite assistance information. 2. The method of clause 1, wherein the receiving an indication of one or more satellites providing the NTN cells includes receiving a non-access stratum (NAS) message from the network including an indication of the one or more satellites providing the NTN cells. 3. The method of clause 2, wherein the NAS message is received from a mobility management entity (MME) of the network. 4. The method of any preceding clause, wherein the one or more satellites providing the NTN cells includes at least one S&F satellite. 5. The method of any preceding clause, wherein the method further includes receiving initial satellite assistance information on at least one satellite of the indicated satellites from the network prior to receiving the indication of one or more satellites providing the NTN cells. 6. The method of clause 5, wherein the initial satellite assistance information is received in broadcast information from the network. 7. The method of clauses 5 or 6, wherein the initial satellite assistance information includes an indication of whether the at least one satellite is an S&F satellite. 8. The method of any preceding clause, wherein the receiving satellite assistance information on the one or more of the indicated satellites on which the UE lacks sufficient information includes receiving satellite assistance information that was not include in the initial satellite assistance information. 9. The method of any preceding clause, wherein the satellite assistance information on the one or more of the indicated satellites that the UE lacks is received from an S&F eNB. 10. The method of any preceding clause, wherein the indication of one or more satellites providing the NTN cells includes an indication of one or more satellite IDs. 11. The method of any preceding clause, wherein the method further includes, indicating by the UE to the network, the satellite assistance information the UE lacks on the one or more of the indicated satellites. 12. The method of any preceding clause, wherein the method further includes determining, by the UE, whether the UE lacks satellite assistance information on the one or more of the indicated satellites. 13. The method of clause 12, wherein the determining, by the UE, whether the UE lacks information on one or more of the indicated satellites, is performed in response to a polling request receiving from the network. 14. The method of any of clauses 1 to 10, wherein the satellite assistance information on the one or more of the indicated satellites that the UE lacks is identified by the network. 15. A user equipment (UE) for operating in a wireless communications network, the wireless communications network including one or more non-terrestrial network (NTN) store and forward (S&F) cells, wherein the UE is configured to perform the method of any preceding clause. Acronyms and Definitions 3GPP 3rd Generation Partnership Project 5G 5th Generation 5GC 5G Core 5QI 5G QoS Identifier 5GS 5G System 5GSM 5G System Session Management 5GMM 5G System Mobility Management AF Application Function Al Artificial Intelligence AM Acknowledged Mode AMF Access and Mobility Management Function AS Access Stratum ASP Application Service Provider ATG Air-To-Ground AUSF Authentication Server Function CDN Content Delivery Network DCAF Data Collection Application Function DNAI Data Network Access Identifier DNN Data Network Name DNS Domain Name Server DRB Data Radio Bearer eNB Evolved Node B EPC Evolved Packet Core E-UTRA Evolved Universal Terrestrial Radio Access FEC Forward Error Correction FQDN Fully Qualified Domain Name GBR Guaranteed Bit Rate gNB Next generation Node B GPSI Generic Public Subscription Identifier HSS Home Subscriber Service IAB Integrated Access and Backhaul ID Identity / ldentifier loT Internet of Things lloT Industrial Internet of Things IMEI International Mobile Equipment Identities IP Internet Protocol l-SMF Intermediate SMF LADN Local Area Data Network LL SSM Lower Layer SSM LTE Long Term Evolution LTE-M LTE-Machine MBMS Multimedia Broadcast / Multicast Service MBS Multicast / Broadcast Service MBSF Multicast / Broadcast Service Function MBSTF Multicast / Broadcast Service Transport Function MB-SMF Multicast / Broadcast Session Management Function MB-UPF Multicast / Broadcast User Plane Function MIB Master Information Block ML Machine Learning MME Mobility Management Entity MN Master Node MNF Monitoring Network Function MNO Mobile Network Operator MT Mobile Termination NAS Non-Access Stratum NB-loT Narrow Band Internet of Things NEF Network Exposure Function NR New Radio NRF Network Repository Function NG-RAN Next Generation Radio Access Network NG-eNB Next Generation eNB NSA Non-Standalone NSSF Network Slice Selection Function NTN Non-Terrestrial Networks NW Network NWDAF Network Data Analytics Function OS Operating System OSAPP OS Application PCF Policy Control Function PCO Protocol Configuration Options PDR Packet Detection Rule PDU Protocol Data Unit PLMN Public Land Mobile Network PTM Point To Multipoint PTP Point to Point QFI QoS Flow Identifier (ID) QoS Quality of Service RACH Random Access Channel RAN Radio Access Network RAT Radio Access Technology RRC Radio Resource Control RSD Route Selection Descriptor SA Standalone SDAP Service Data Adaptation Protocol SDU Service Data Unit S&F Store and Forward SGW Serving Gateway SIB System Information Block SIM Subscriber Identity Module SLA Service Level Agreement SM Session Management SMF Session Management Function SN Secondary Node S-NSSAI Single Network Slice Selection Assistance Information SSB Synchronization Signal Block SSM Source Specific IP Multicast address SSC Session and Service Continuity SRB Signaling Radio Bearer SUPI Subscription Permanent Identifier TA Tracking Area TAI Tracking Area Identity TE Terminal Equipment TM Transparent Mode TMGI Temporary Mobile Group Identity TN Terrestrial Network TS Technical Specification UAV Unmanned Aerial Vehicle UDM Unified Data Manager UDR Unified Data Repository UE User Equipment UL Uplink UM Unacknowledged Mode UP User Plane UPF User Plane Function URLLC Ultra-Reliable and Low-Latency Communication URSP UE Route Selection Policy

Claims

1. A method of a user equipment (UE) for operating in a wireless communications network, the wireless communications network including one or more non-terrestrial network (NTN) store and forward (S&F) cells, the method comprising:receiving an indication of one or more satellites providing the NTN S&F cells;receiving, from the network, satellite assistance information on the one or more of the indicated satellites; andperforming an idle mode operation based on the received satellite assistance information.

2. The method of claim 1, wherein performing an idle mode operation based on the received satellite assistance information includes performing an idle mode operation when in coverage of the one or more satellites providing the NTN S&F cells.

3. The method of claims 1 or 2, wherein performing an idle mode operation based on the received satellite assistance information includes not performing an idle mode operation when not in coverage of the one or more satellite providing the NTN S&F cells.

4. The method of any preceding claim, wherein the UE enters a reduced power mode (e.g. a sleep mode or a discontinuous coverage mode) outside coverage of the one or more satellites providing the NTN S&F cells.

5. The method of any preceding claim, wherein the UE wakes up from a reduced power mode when in coverage of the one or more satellite providing the NTN S&F cells.

6. The method of any preceding claim, wherein the receiving an indication of one or more satellites providing the NTN S&F cells includes receiving a non-access stratum (NAS) message from the network including an indication of the one or more satellites providing the NTN S&F cells.

7. The method of claim 6, wherein the NAS message is received from a mobility management entity (MME) of the network.

8. The method of any preceding claim, wherein the satellite assistance information is received in broadcast information from the network.

9. The method of any preceding claim, wherein the satellite assistance information is received in system information broadcast by the network.

10. The method of any preceding claim, wherein the satellite assistance information includes ephemeris information and service start time information.

11. The method of any preceding claim, wherein the method further includes determining a coverage of the one or more NTN S&F cells based on the satellite assistance information.

12. The method of any preceding claim, wherein the satellite assistance information is received from an S&F eNB.

13. The method of any preceding claim, wherein the receiving, from the network, satellite assistance information on the one or more of the indicated satellites includes receiving satellite assistance information for the indicated satellites the UE lacks satellite assistance information on.

14. The method of claim 13, further comprising: transmitting, to the network, an indication of the satellite(s) the UE lacks satellite assistance information on.

15. The method of claim 14, wherein the indication of the satellite(s) the UE lacks satellite assistance information on includes satellite ID(s) of the satellite(s) the UE lacks satellite assistance information on.

16. The method of claims 14 or 15, wherein the indication of the satellite(s) the UE lacks satellite assistance information on is sent via a radio resource control (RRC) message.

17. The method of any of claims 14 to 16, further comprising:receiving, from the network, a request to check if the UE lacks satellite assistance information on the one or more satellites providing the NTN S&F cells;checking if the UE lacks satellite assistance information on the one or more satellites providing the NTN S&F cells; andif the UE lacks satellite assistance information on the one or more satellites providing the NTN S&F cells, transmitting, to the network, the indication of the satellites the UE lacks satellite assistance information on.

18. The method of any preceding claim, wherein the indication of one or more satellites providing the NTN S&F cells includes a list of one or more satellite IDs.

19. The method of any preceding claim, wherein the UE is a Internet of Things (loT) device.

20. The method of any preceding claim, wherein the idle mode operation includes performing measurements on an NTN cell for cell selection.

21. A user equipment (UE) for operating in a wireless communications network, the wireless communications network including one or more non-terrestrial network (NTN) store and forward (S&F) cells, wherein the UE is configured to perform the method of any preceding claim.

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