GB2609491A

GB2609491A - UE location access control

Info

Publication number: GB2609491A
Application number: GB2111336.0A
Authority: GB
Inventors: Khirallah Chadi
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2023-02-08

Abstract

A method for reporting UE location information in a network (e.g. a Non-Terrestrial Network (NTN)). The method comprises receiving, by a first entity (e.g. NG-RAN node), location information from the UE; determining, by a second entity (e.g. Access and Mobility Management Function (AMF)), whether the location information corresponds to an allowed or restricted location and selectively performing a connection procedure (e.g. UE registration) for the UE based on the determining. The location information may be received in a RRCSetupComplete message relating to initial access of the UE to the network. The first and second entities may be the same and may be a base station (e.g. NG-RAN) and the location information may be received in a RRCResumeRequest message relating to resuming a previously released connection of the UE to the network. The location information may comprise information indicating; a cell, a tracking area, or a sub-area of a tracking area. Also provided are first and second network entities configured to operate according to the provided method, and a network comprising the first and second network entities.

Description

UE Location Access Control BACKGROUND

Field

Certain examples of the present disclosure provide methods, apparatus and systems for providing UE location access control in a network. For example, certain examples of the present disclosure provide methods, apparatus and systems for providing UE location access control in a 3GPP 5G Non-Terrestrial Network (NTN).

Description of the Related Art

One of the areas currently under development in 3GPP 5G wireless technology is support for non-terrestrial networks (NTNs). An NTN is a network in which one or more nodes (e.g. NO-RAN node) are provided by a non-terrestrial infrastructure, for example a satellite or High Altitude Platform Station (HAPS). Advantages of using an NTN include (i) extending coverage to regions, such as remote areas, with limited or no coverage from more traditional terrestrial networks, (h) providing continuous coverage in the event of inoperability of traditional terrestrial networks, such as during natural disasters, and (Hi) enhancing overall reliability, resilience and capacity when used in conjunction with existing terrestrial networks.

A satellite network implementing a network node (e.g. NO-RAN node) provides coverage through one or more radio beams forming a "footprint" on the surface of the Earth defining a coverage area or cell. An NTN cell may be Earth-moving (i.e. moving over the Earth's surface according to the motion of the satellite) or Earth-fixed (i.e. a fixed area of the Earth's surface, for example in the case of a GEO satellite). An NTN cell may have a size in a range between tens to thousands of kilometres, and may cover multiple geographical regions (e.g. countries). In this case, a User Equipment (UE) may be able to move between different geographical locations within the same cell. The node may need to select an AMF of a core network (CN) that could serve the UE in its geographical location.

Figure 1 schematically illustrates an NTN NG-RAN node implemented as a satellite with a beam having a footprint defining an NTN cell covering three countries (A, B and C). The NGRAN node is connected to three AMF/CN (A, B and C) that serve UEs located in respective countries (A, B and C). A UE is illustrated in Figure 1 as being located in country B, and therefore the NG-RAN needs to select AMF/CN B to serve the UE.

The NO-RAN node needs the UE location in order to perform CN selection.

The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.

SUMMARY

It is an aim of certain examples of the present disclosure to address, solve and/or mitigate, at least partly, at least one of the problems and/or disadvantages associated with the related art, for example at least one of the problems and/or disadvantages described herein. It is an aim of certain examples of the present disclosure to provide at least one advantage over the related art, for example at least one of the advantages described herein.

The present invention is defined in the independent claims. Advantageous features are defined in the dependent claims.

Embodiments or examples disclosed in the description and/or figures falling outside the scope of the claims are to be understood as examples useful for understanding the present invention.

Other aspects, advantages and salient features of the invention 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 Figure 1 schematically illustrates a simplified example of an NTN; Figure 2 illustrates an NTN cell covering four countries with a border area at the intersection of the countries; Figure 3 is a signal flow diagram of an example of the present disclosure in which a UE reports location/area information to a network in the case of initial UE access; Figure 4 is a flow chart of an example of the present disclosure in which a UE reports location/area information to a network in the case of RRC Resume; Figure 5 is a signal flow diagram corresponding to the example of Figure 4; Figure 6 is a flow chart of an example of the present disclosure in which location/area information reported by a UE is verified by the network in the case of RRC Resume; Figure 7 is a signal flow diagram corresponding to the example of Figure 6; Figures 8a and 8b illustrate techniques of dividing a Tracking Area into sub-areas of variable or fixed size; and Figure 9 is a block diagram of an exemplary network entity that may be used in certain examples of the present disclosure.

DETAILED DESCRIPTION

The following description of examples of the present disclosure, with reference to the accompanying drawings, is provided to assist in a comprehensive understanding of the present invention, as defined by the claims. 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.

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

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 invention.

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 invention.

Throughout the description and claims 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.

Throughout the description and claims 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.

Throughout the description and claims 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. Features, elements, components, integers, steps, processes, operations, functions, characteristics, properties and/or groups thereof described or disclosed in conjunction with a particular aspect, embodiment, example or claim of the present invention are to be understood to be applicable to any other aspect, embodiment, example or claim described herein unless incompatible therewith.

Certain examples of the present disclosure provide methods, apparatus and systems for providing UE location access control in a network. For example, certain examples of the present disclosure provide methods, apparatus and systems for providing UE location access control in a 3GPP 5G NTN. However, the skilled person will appreciate that the present invention is not limited to these examples, 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, including any existing or future releases of the same standards specification, for example 3GPP 5G.

The following examples are applicable to, and use terminology associated with, 3GPP 5G.

However, the skilled person will appreciate that the techniques disclosed herein are not limited to 3GPP 5G. 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 or purpose within the network. For example, the functionality of the AMF in the examples below may be applied to any other suitable type of entity performing mobility management functions, the functionality of the UDM in the examples below may be applied to any other suitable type of entity performing data management functions, and the functionality of the NG-RAN node (e.g. base station) in the examples below may be applied to any other suitable type of entity performing RAN functions. The skilled person will also appreciate that the transmission of information between network entities is not limited to the specific form, type or order of messages described in relation to the examples disclosed herein.

A particular network entity may be implemented 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.

The skilled person will appreciate that the present invention is not limited to the specific examples disclosed herein. For example: * The techniques disclosed herein are not limited to 3GPP 5G.

* 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 or entities may be added to the examples disclosed herein.

* One or more non-essential elements or entities 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 and/or the order in which messages are transmitted may be modified, if possible, in alternative examples.

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. Certain examples of the present disclosure may be provided in the form of a system (e.g. network or wireless communication system) comprising one or more such apparatuses/devices/network entities, and/or a method therefor.

An NTN deployment may have a cell that covers multiple geographical regions (e.g. countries), one or more cells that cover a single geographical region (e.g. country) and/or multiple cells that cover respective geographical regions (e.g. countries). NTN cells may be served by the same or different NG-RAN nodes in the same or different geographical regions (e.g. countries) An NG-RAN node corresponding to a cell may need to select an AMF of a ON that can serve a UE located within the cell according to the particular geographical location in which the UE is located. To perform such a selection, the NO-RAN node needs to know the UE location.

There are certain problems associated with this process.

The NG-RAN node may not be able to select a suitable AMF/CN without precise UE location information. This problem may be exacerbated if the UE is located on or close to a country border. For example, at a border area, it may be difficult for the UE to report its location accurately. Suitable AM F/CN selection is important, and if the wrong AM F/CN is selected then the selection needs to be corrected. Figure 2 illustrates an NTN cell covering four countries with a border area at the intersection of the countries.

A UE may not be allowed access in certain locations/areas in the NTN cell (e.g. contested borders, restricted areas, etc.). In the existing standard, it is not yet defined which network entity (e.g. NG-RAN and/or ON) can restrict UE access to different locations/areas in an NTN cell, and how such restriction may be implemented.

UE location information may be provided to the NG-RAN after AS security has been enabled. In the current standard, it is not yet defined how UE location information may be provided to the NG-RAN before AS security establishment (e.g. during initial UE access to the network).

UE location information may not be considered reliable or trusted unless the information is verified by the network. In the current standard, it is not yet defined how UE location information may be verified by the network and which network entity (e.g. NG-RAN and/or ON) may perform such verification.

Certain examples of the present disclosure provide one or more techniques that aim to address one or more of the above problems. The skilled person will appreciate that the various techniques described herein may be used individually or in any suitable combination (when compatible). For example, a technique in which location/area information is verified (e.g. the technique of Figures 6 and 7) may be used in combination with, or independently from, a technique in which a UE reports location/area information (e.g. the techniques of Figures 3 to 5), and a technique in which a tracking area or cell may be divided into sub-areas (e.g. the techniques of Figures 8a and 8b) may be used in combination with, or independently from, techniques in which a UE reports location/area information and/or in which location/area information is verified.

Figure 3 is a signal flow diagram of an example of the present disclosure in which a UE reports location/area information of the UE to the network in the case of initial UE access. As well as the UE, the network comprises an NTN NG-RAN, and AMF entity and a UDM entity. In various examples, the network may comprise one or more other entities performing various network functions.

In Step 1, the UE reports its location/area information to the NG-RAN node via signalling (e.g. RRC signalling). The location/area information may comprise GNSS location information, area information, a combination of both, and/or any other suitable type of positioning information. For example, the RRC signalling may comprise an RRCSetupComplete message (or any other suitable message). In the present disclosure, references to location information may be interpreted as optionally also including area information in certain examples, and references to area information may be interpreted as optionally also including location information in certain examples.

The information may be included in the signalling in any suitable manner. For example, the information may be included in any suitable existing or new IF in the message. The IF may include an Assistant Location Information IE with one or more pieces of information, for example one or more of: location information, distance to reference point area, time stamp on UE presence in the location, location measurement method, predicted accuracy of measurements, information on previous location(s) visited by the UE, velocity of the UE, direction of movement of the UE, and any other suitable information. The IE may include an Assistant Area Information IF with one or more pieces of information, for example one or more of: area index, time stamp on UE presence in the area, area measurement method, predicted accuracy of measurements, information on previous area(s) visited by the UE, velocity of the UE, direction of movement of the UE, and any other suitable information. Some examples of a method of obtaining the UE area information (at the UE) are described below.

In Step 2, the NG-RAN node, based on the location/area information received from the UE, selects a suitable AMF that could serve the UE in its reported location/area.

In Step 3, the NG-RAN node reports the location/area information to the selected AMF. For example, the location/area information may be reported using NGAP signalling, for example included in the "Initial UE Message". The location/area information may be fully reported, partially reported, or reported as a modified/enhanced version by the NG-RAN node. For example, the NG-RAN node may enhance the accuracy of the location/area information using information from additional measurements/predictions, of the UE location/area, that are performed at the NG-RAN. That is, the location/area information may be reported in a modified or unmodified form. In certain examples, the NG-RAN node may optionally report a mapping of Areas per TA/Cell to the AMF (see below).

In Step 4, the AMF retrieves UE subscription from the UDM.

The AMF may obtain a List of Allowed or Restricted/Excluded Locations/Areas. For example, the List may be generated (e.g. by the AMF) based on subscriber information received from UDM and information on the list of Locations/Areas (per TA/Cell). The information on the list of Locations/Areas (per TA/Cell) may be preconfigured in the AMF or received from another Network Function (NF). The list may be provided (e.g. directly) to the AMF by another NF (e.g., PCF, or other NF(s)) based on countries policies/regulations on geographic locations/areas that UE(s) are allowed access or restricted/exclude from operation in.

In Step 5, the AMF verifies, based on the UE subscription (i.e. based on the List of Allowed or Restricted/Excluded Locations/Areas), whether the UE is allowed access/service in the reported location/area. Depending on whether or not the UE is allowed access/service, either Step 6a or Step 6b is performed.

In Step 6a, if UE access/service is allowed, the AMF completes the registration procedure in conjunction with the NG-RAN node and the UE. The AMF may send to the NG-RAN node and/or the UE a list of allowed/restricted locations/areas per TA (or Cell if available). For example, the AMF may send this information using a separate existing or new IE (e.g. "Allowed/Restricted Locations/Areas List" 1E) in a suitable message. In certain examples, this IE may be included in the "Initial Context Setup Request" message. Alternatively, this IE may be included as part of the "Mobility Restriction List" IE in the "Initial Context Setup Request" message. In certain examples, the NG-RAN node can pass the "Allowed/Restricted Locations/Areas List" IE transparently towards the UE.

In Step 6b, if the UE access/service is forbidden, the AMF rejects the UE Registration Request.

The AM F may provide a cause of rejection to the UE, for example a "cause value" indicating "no access allowed in this location/area". As with Step 6a above, the AMF may send to the NG-RAN node and/or the UE a list of allowed/restricted locations/areas per TA (or Cell if available). In this case, the UE may be redirected to attempt registration in one of the allowed locations/areas of the TA/Cell, specified in the allowed locations/area list, where the UE is located.

The "Allowed/Restricted Locations/Areas" list may include one or more of the following exemplary pieces of information. For example, in the case of Allowed/Restricted Areas list: * List of Areas in TA (1... number of Areas) * Tracking Area Index (TAI) * Area Index * indication of permission for Area (e.g. Allowed Area, Forbidden Area, partially Allowed, partially Forbidden, Allowed or Forbidden for a given period of time, other) * Other information (if UE was previously registered with the AMF -see the further examples below), for example including one or more of: o List of Areas previously visited by the UE o Area Index o Time of UE presence in the Area o Time since UE report the Area Information o UE velocity o UE movement direction o Other information The following examples relate to situations in which the UE registers with the AMF, then the NG-RAN releases the UE and the UE resumes the RRC connection.

Figure 4 is a flow chart of an example of the present disclosure in which a UE reports location/area information to a network in the case of resuming a connection, and Figure 5 is a signal flow diagram corresponding to the example of Figure 4. The examples of Figures 4 and 5 involve RRC Resume, but the skilled person will appreciate that the techniques disclosed herein may be applied to other types of resume.

Referring first to Figures, in operation 501, the UE and NG-RAN perform a setup procedure (e.g. RRCSetup). As part of this procedure, the UE reports its location/area information to the NG-RAN via signalling (e.g. RRC signalling), for example in a manner corresponding to Step 1 of Figure 3. In operation 502, the NG-RAN, based on the location/area information received from the UE, selects a suitable AMF that could serve the UE in its reported location/area, for example in a manner corresponding to Step 2 of Figure 3. In operation 503, the NG-RAN reports the location/area information to the selected AMF, for example in a manner corresponding to Step 3 of Figure 3. If the UE is allowed access, the AMF and the UE complete the registration procedure, for example in a manner corresponding to Steps 4, 5 and 6a of Figure 3. These operations are not shown in Figure 5.

Referring now to Figure 4, in operation 401, after successful UE registration, the AMF initiates a UE context setup procedure. In particular, as shown in Figure 5, in operation 504, the AMF transmits an INITIAL CONTEXT SETUP REQUEST message to the NG-RAN. In response, in operation 505, the NG-RAN transmits an INITIAL CONTEXT SETUP RESPONSE message to the AMF. As shown in Figure 4, in operation 402, the AMF sends to the NG-RAN a list of Allowed/Restricted Locations/Areas per TA (or per Cell, if available). As shown in Figure 5, this list may be sent in the INITIAL CONTEXT SETUP REQUEST message of operation 504. In operation 403 of Figure 4 and operation 506 of Figure 5, the NG-RAN stores the list of Allowed/Restricted Locations/Areas per TA (or per Cell, if available). These operations correspond to operations described above in relation to Step 6a of Figure 3.

As shown in Figure 5, in operation 507, the UE and NG-RAN perform a reconfiguration procedure (e.g. RRCReconfiguration), and in operation 508, data transmission may occur between the AMF and the UE In operation 404 of Figure 4 and operation 509 of Figure 5, the NG-RAN releases the UE. For example, the NG-RAN may transmit a message (e.g. RRCRelease with/without suspend) to the UE. The message may include a list of allowed/restricted location/area per TA (or per Cell, if available).

Subsequently, in operation 405 of Figure 4 and operation 510 of Figure 5, the UE may request to resume the connection with the NG-RAN by transmitting a resume request message (e.g. RRCResumeRequest) to the NG-RAN. The UE reports its location/area information to the NG-RAN. For example, the UE may include the location/area information in the resume request message (or any other suitable message).

Next, in operation 406 of Figure 4 and operation 511 of Figure 5, the NG-RAN checks if the UE is allowed access to the area/location indicated by the location/area information received from the UE. That is, the NG-RAN checks that the UE location/area reported by the UE is included in the list of Allowed Locations/Areas per TA (or per Cell, if available) stored in the UE context following completion of operation 403 of Figure 4 and operation 506 of Figure 5.

If the UE is allowed access, then in operation 407a of Figure 4 and operations 512a and 513a of Figure 5, the UE connection is resumed. For example, the NG-RAN may transmit a resume message (e.g. RRCResume) to the UE in operation 512a and the UE may respond by transmitting a resume complete message (e.g. RRCResumeComplete) to the NG-RAN in operation 513a.

On the other hand, if the UE is not allowed access, then in operation 407b of Figure 4 and operations 512b and 513b of Figure 5, the UE connection resumption request is rejected. For example, the NG-RAN may transmit a reject message (e.g. RRCReject) to the UE in operation 512b. In certain example, the NG-RAN node provides the UE with the "Allowed/Restricted Locations/Areas List" IE included in a reject message (e.g. RRCReject) to the UE. In this case, the UE may request connection setup based on one of the allowed locations/areas of the TA (or Cell, if available), specified in the allowed locations/areas list, where the UE is located, by transmitting a request message (e.g. RRCSetupRequest) to the NG-RAN in operation 513b.

Figure 6 is a flow chart of an example of the present disclosure in which location/area information reported by a UE is verified by the network in the case of resuming a connection, and Figure 7 is a signal flow diagram corresponding to the example of Figure 6. The examples of Figures 6 and 7 involve RRC Resume, but the skilled person will appreciate that the techniques disclosed herein may be applied to other types of resume.

Operations 601-605 of Figure 6 correspond to operations 401-405 of Figure 4, and operations 701-710 of Figure 7 correspond to operations 501-510 of Figure 5, and therefore the detailed description of these operations are not described again.

In operation 606-608 of Figure 6 and operation 711 of Figure 7, the NG-RAN verifies the location/area information reported by the UE in operation 605 of Figure 6 and operation 710 of Figure 7.

For example, in operation 606 of Figure 6, the NG-RAN may obtain assistance information about the UE from the AMF. The assistance information may include information on previously accessed locations/areas per TA (or Cell, if available) for the UE. For example, the assistance information may include one or more pieces of the information described above as examples of "other information" included in the "Allowed/Restricted Locations/Areas" list. The assistance information may be stored in the UE context. The skilled person will appreciate that the assistance information may be generated or obtained by any suitable Network functions, not limited to the AMF. When the assistance information is not obtained or generated by the AMF, the assistance information may be passed to the NG-RAN via the AMF, or in other ways not necessarily including the AMF. In certain examples, the assistance information could be in the form of prediction of UE location, area, and/or mobility patterns over a given time period.

Then, in operation 607 of Figure 6, the NG-RAN estimates the UE location/area based on the assistance information and/or local prediction methods in the NG-RAN. The NG-RAN then compares the estimated UE location/area information with the UE location/area information reported by the UE. For the comparison, the estimated UE location/area information may be a central point, or any other suitable reference point, of the estimated location/area.

The NG-RAN verifies the location information reported by the UE based on a result of the comparison. For example, in operation 608 of Figure 6, if the difference between the estimated UE location/area information and the reported UE location/area information is less than a predetermined threshold then the reported UE location/area information is verified (i.e. accepted as the UE location/area), otherwise the reported UE location/area information is not verified (i.e. rejected as the expected UE location/area).

If the reported UE location/area information is verified, then in operation 609a of Figure Sand operations 712a and 713a of Figure 7, the UE connection is resumed, for example in a similar manner to operation 407a of Figure 4 and operations 512a and 513a of Figure 5.

On the other hand, if the reported UE location/area information is not verified, then in operation 609b of Figure 6 and operations 712b and 713b of Figure 7, the UE connection resumption request is rejected, for example in a similar manner to operation 407b of Figure 4 and operations 512b and 513b of Figure 5. The reject message transmitted from the UE to the NG-RAN may optionally include an indication that the reported location/area is incorrect/not verified. In certain example, the NG-RAN node provides the UE with the Allowed/Restricted Locations/Areas List" IE included in the reject message (e.g. RRCReject) to the UE In various examples (e.g. the examples of Figures 3 to 7), the network may provide or indicate a list of Allowed and/or Restricted locations/areas (e.g. per TA or per Cell) to one or more UEs in any suitable manner. In certain examples, the list may be provided in a System Information broadcast (e.g., SIB1 or Separate message or SIB). The broadcast may be done periodically, on-demand by the UE (e.g., MSG1/MSG3), in response to a triggering event, or according to any other suitable technique. In certain examples, the list may be provided in signalling. The signalling may include dedicated AS signalling (e.g. RRC signalling). Examples of signalling that may be used include RRC Reconfiguration (when the UE is in RRC_CONNECTED state), and RRC Release (on moving the UE to RRC_INACTIVE state), or RRC Reject. The signaling may include dedicated NAS signaling. For example, the AMF may send the list of Allowed and/or Restricted locations/areas to the UE during the UE registration process. In this case, the list of Allowed and/or Restricted locations/areas IE (as a separate or part of an existing 1E) may be included in the INITIAL CONTEXT SETUP REQUEST message. The NG-RAN node may or shall pass the list transparently towards the UE.

In various examples (e.g. the examples of Figures 3 to 7), the network may provide or indicate an updated list of Allowed and/or Restricted locations/areas (e.g. per TA or per Cell) to one or more UEs in any suitable manner. For example, the updated list may be provided using a System Information update procedure, signaling (e.g. dedicated AS signaling or dedicated NAS signaling), or any other suitable method.

In various examples (e.g. the examples of Figures 3 to 7), the network may provide or indicate a list and/or updated list of Allowed and/or Restricted locations/areas (e.g. per TA or per Cell) to one or more NG-RAN nodes in any suitable manner. For example, the list and/or updated list may be provided using NG signalling. In this case, the list may be included in an INITIAL CONTEXT SETUP REQUEST message (or any other suitable message) and/or an updated list may be included in the UE CONTEXT MODIFICATION REQUEST message (or any other suitable message).

In various examples, various location/area permission and/or restrictions may be defined. In certain examples, some or all UEs may be restricted from operation/access in "Restricted Locations/Areas", for example permanently or for a given period of time. In certain examples, some or all UEs may be permitted to operate or access in "Allowed Locations/Area", permanently or for a given period of time. In certain examples, some or all UEs may be restricted from operating in a defined "Restricted Locations/Areas". In certain examples, one or more UEs may be allowed in the Restricted Locations/Areas. In certain examples, the validity of permission/restriction to access a location/area, for UE(s), may be modified, for example following updated policies in the network and/or updated regulations in in different countries.

In various examples, a UE may identify an Allowed or Restricted Location/Area in any suitable manner. In the case that the UE has the list: if the UE obtained the list of Allowed/Restricted Locations/Areas (e.g. via broadcast, dedicated AS signalling, or Dedicated NAS signalling), assuming that the UE has its location/area information, then the UE may compare its location/areas against the list to find out whether it is allowed or restricted from accessing its current location/area (or next location/area), for example permanently or for a given period of time. In the case that the UE does not have the list: during UE access to an NTN cell, the UE may send its current location/area to the NG-RAN and then the network (e.g. NG-RAN and/or AMF) may verify whether the UE is permitted or restricted from accessing the current location/area. The network may inform the UE whether it is allowed or restricted from accessing the current location or area, for example permanently or for a given period of time.

The skilled person will appreciate that, in the various examples disclosed herein, certain operations performed by a particular network entity may be performed by a different network entity in alternative examples. In such alternative examples, any information required to perform a certain operation may be provided to the relevant network entity performing the operation via suitable messages transmitted to that network entity. For example, the operations of Steps 2 and 5 in Figure 4 may be performed by suitable network entities other than the NG-RAN node and AMF, respectively, in alternative examples. Similarly, operation 711 of Figure 7 and operation 511 of Figure 5 may be performed by suitable network entities other than the NG-RAN node in alterative examples.

Figures 8a and 8b illustrate techniques of dividing a Tracking Area into sub-areas. The skilled person will appreciate that a similar technique may be used to divide an NTN cell into sub-areas.

An NTN cell may include one or more TAs. Figures 8a and 8b illustrate examples in which an NTN cell includes two TAs (TA1 and TA2). A TA may be virtually divided into two or more subareas. The sub-areas may correspond to fixed geographical areas having sizes and/or shapes that are configurable by the network, as in the example of Figure 8a. Alternatively, the sub-areas may correspond to N (e.g. N=28) fixed (non-configurable) geographical areas, as in the example of Figure 8b.

In the case of configurable sub-areas, the list of TA(s) and corresponding Areas per TA/Cell may be pre-configured in the NG-RAN node serving the NTN cell, and the NG-RAN node may provide the Area Information per TA (or per Cell, if available) to the UE (e.g. broadcast as part of system information, or using dedicated signalling).

Each resulting sub-area (e.g. A0-A27 in the case of 28 sub-areas) may be represented by an Area Index using a suitable number of bits (e.g. 5 bits). Figure 8b illustrates the case in which the UE is located in sub-area AO of TA1. AO corresponds to a Reference Area in TA1 in Figures 8a and 8b. Figure 8b also illustrates examples of certain sub-areas where the UE is not allowed to access.

In certain examples, the Area Information may include on or more of the following pieces of information: * List of Areas in TA (1... number of Areas) * TA Index (TAI) * Area Index * Reference Area coordinates (e.g. universal or local Geographical Area) * Area Radius * TA Radius (e.g. 10s, 100s, 10005 kilometres) * Direction of Area mapping (e.g. clockwise or anticlockwise) * Other Information Some or all of the Area Information may be sent from NG-RAN to the UE. For example, the NG-RAN may provide the Area Information per TA (or per Cell, if available) to the UE as part of System Information broadcast (e.g. SIB1 or separate message or SIB). The information may be broadcast periodically or on demand by the UE (e.g. MSG1/MSG3). Alternatively or additionally, the NG-RAN may provide the Area Information per TA (or per Cell, if available) to the UE as dedicated signalling (e.g. RRC signalling). The signalling may include, for example, RRC Reconfiguration (UE in RRC_CONNECTED state), RRC Release (on moving the UE to RRC_INACTIVE state), or any other suitable signalling.

The identity of a zone may be calculated using any suitable technique. One example is given in the following. The UE may determine an identity of the zone (i.e. Zone_id) in which it is located using the following formulae, if sl-ZoneConfig is configured: x1= Floor (x/ L) Mod 64; yi= Floor (y / L) Mod 64; Zone_id = * 64 + xl.

The parameters in the formulae are defined as follows: L is the value of s/-ZoneLength included in s/-ZoneConfig; x is the geodesic distance in longitude between UE's current location and geographical coordinates (0, 0) according to WGS84 model and it is expressed in meters; y is the geodesic distance in latitude between UE's current location and geographical coordinates (0, 0) according to WGS84 model and it is expressed in meters.

An example of use of the calculated zone_id is specified in 3GPP TS 38.321.

The skilled person will appreciate that the technique of dividing a Tracking Area (or Cell) into sub-areas may be applied to any of the examples disclosed herein, including the examples of Figures 1-7.

Further techniques will now be described relating to an Xn Interface, in particular in the cases of Setup, Configuration Update and Xn Handover.

The following relates to an Xn Setup procedure (non-UE associated). During Xn interface setup between two NG-RAN nodes, the list of Allowed and/or Restricted Areas may be exchanged between the two NG-RAN nodes (NG-RAN node 1 and node 2). For example, the XN SETUP REQUEST message and XN SETUP RESPONSE message may contain, for each cell served by NG-RAN node 1 and 2, Area Information (for example, provided to UEs using broadcast, dedicated signalling and/or any other suitable method) and a list of Allowed and/or Restricted Locations/Areas (in each cell). Each NG-RAN will be aware of its neighbour's Area Information and list of Allowed and/or Restricted Locations/ Areas. Such a list of Allowed/Restricted Location/Areas may be for all UEs.

The following relates to NG-RAN node Configuration Update procedure (non-U E associated).

During an NG-RAN node Configuration Update procedure, two NG-RAN nodes may exchange, for each cell, updated information/configuration of the Area Information (for example, an updated number of areas per TA/Cell, and/or shape and/or size of the Areas) and an updated list of Allowed and/or Restricted Locations/Areas (in each cell), for example change of regulations and policies on restricted locations/areas. For example, if the List of Allowed and or Restricted Locations/Areas IE (or other named 1E) is included in the NG-RAN NODE CONFIGURATION UPDATE message, the receiving NG-RAN replaces the previously provided List of Allowed and or Restricted Locations/Areas 1E with the received List of Allowed and or Restricted Locations/Areas IE.

The following relates to Xn Handover procedure (UE associated). During Xn Handover Preparation procedure, the source NG-RAN node may send to the Target NG-RAN node information on the location(s)/Area(s) that the UE intends to access in the target cell. The source NG-RAN node may obtain a prediction of the potential locations or areas that the UE may access in the Target cell(s) under the Target NG-RAN node. Such a prediction may be calculated by NG-RAN node or any other suitable CN node/network function. For example, information on a "list of Areas/Locations IE" (or any other named 1E) that the UE intends to access or is predicted to access (e.g. or a given time period) may be sent On a HANDOVER REQUEST as a separate new 1E, or as in the existing "Mobility Restriction List IE") in the HANDOVER REQUEST message. Based on the received list of Areas/Locations IF that the UE intends to access or is predicted to access, the Target NG-RAN node may reject or accept the UE handover. In the case of the Target NG-RAN node rejecting the UE handover, the Target NG-RAN node may indicate to the source NG-RAN the list of rejected Locations/Areas. For example, the target NG-RAN node may send a HANDOVER PREPARATION FAILURE message that includes a new IE ("Requested Location", "Requested Area Index", "Rejected Location", "Rejected Area Index", or any other named 1E) and a rejection cause value "Area is Restricted", "Area is not supported", Location is Restricted", "Location is not supported", or any other named cause value. The Target NG-RAN node may accept the UE handover, and indicate to the source NG-RAN node a List of Accepted Locations/Areas IE and /or List of Rejected Locations/Areas 1E, for example included in an HANDOVER REQUEST ACKNOWLEDGE message. The Target NG-RAN node may also include other assistance information (for example in the above two messages), for example Locations/Areas with Hybrid access permission (e.g. access/restriction is valid for a given period of time).

As mentioned above, NTN cells may be served by the same or different NG-RAN nodes in the same or different geographical regions (e.g. countries). In the case of XN SETUP/Handover between NTN NG-RANs across geographical boundaries (e.g. county borders) or within the same geographical area (e.g. country), the NG-RAN nodes can exchange the list of Allowed/Restricted Locations/Areas.

In certain examples of the present disclosure, it is determined whether location information corresponds to an allowed location (e.g. using a list of allowed locations). The skilled person will appreciate that the techniques described herein may also be applied to the converse case in which it is determined whether location information corresponds to a restricted location (e.g. using a list of restricted locations).

Certain examples of the present disclosure provide a method for reporting UE location information in a network (e.g. an NTN) comprising the UE, a base station (e.g. NG-RAN node) and one or more AMF entities, the method comprising: receiving, by the base station, from the UE, a first message (e.g. RRCSetupComplete) relating to initial access of the UE to the network, the first message including location information of the UE; selecting, by the base station, an AMF entity based on the location information; determining, by the selected AMF entity, whether the location information corresponds to an allowed location (and/or a restricted location); and selectively performing completion of a UE registration procedure based on the result of the determining.

Certain examples of the present disclosure provide a method for reporting UE location information in a network (e.g. an NTN) comprising the UE and a base station (e.g. NG-RAN node), the method comprising: receiving, by the base station, from the UE, a fourth message (e.g. RRCResumeRequest) relating to resuming a previously released connection of the UE to the network, the fourth message including location information of the UE; determining; by the base station, whether the location information corresponds to an allowed location (and/or a restricted location) for the UE based on the received location information and a previously stored list of allowed locations (and/or a previously stored list of restricted locations) for the UE; and selectively resuming the previously released connection of the UE to the network based on the result of the determining.

Certain examples of the present disclosure provide a method for verifying UE location information in a network (e.g. an NTN) comprising the UE and a base station (e.g. NG-RAN node), the method comprising: receiving, by the base station, from the UE, a fifth message (e.g. RRCRelease), the fifth message including location information of the UE; verifying, by the base station, the received location information based on previously stored information related to the UE; and selectively performing an operation (e.g. resuming a previously released connection of the UE to the network) based on the result of the verifying Certain examples of the present disclosure provide a method for reporting UE location information in a network (e.g. an NTN) comprising the UE and one or more network entities, the method comprising: receiving, by a first network entity, from the UE, location information of the UE; determining, by a second network entity, whether the location information corresponds to an allowed location (and/or a restricted location); and selectively performing a connection procedure for the UE based on the result of the determining.

In certain examples, the first network entity may be a base station (e.g. NG-RAN node) and the location information may be received in a first message (e.g. RRCSetupComplete) relating to initial access of the UE to the network, the second network entity may be an AMF entity selected by the first network entity based on the location information, and the connection procedure may comprise completion of a UE registration procedure.

In certain examples, the method may further comprise: receiving, by the second network entity, from the first network entity, a second message (e.g. Initial UE message) including the location information; receiving, by the second network entity, from a third network entity (e.g. UDM entity), a third message comprising a UE subscriber/information profile, wherein the second network entity may determine whether the location information corresponds to an allowed location (and/or a restricted location) for the UE based on the received location information and information contained in the UE subscriber/information profile.

In certain examples, the method may further comprise transmitting, from the second network entity to the first network entity, a list of allowed locations (and/or a list of restricted location) for the UE.

In certain examples, selectively performing the connection procedure may comprise: completing a UE registration procedure if the location information corresponds to an allowed location; or rejecting the UE registration procedure if the location information does not correspond to an allowed location.

In certain examples, the first network entity may be the same as the second network entity and may be a base station (e.g. NG-RAN node), and the location information may be received in a fourth message (e.g. RRCResumeRequest) relating to resuming a previously released connection of the UE to the network, the first network entity may determine whether the location information corresponds to an allowed location (and/or a restricted location) for the UE based on the received location information and a previously stored list of allowed locations (and/or a previously stored list of restricted location) for the UE, and the connection procedure may comprise resuming the previously released connection of the UE to the network.

In certain examples, the method may further comprise transmitting, from the first network entity to the UE, a list of allowed locations (and/or a list of restricted locations) for the UE.

In certain examples, selectively performing the connection procedure may comprise: resuming the previously released connection of the UE to the network if the location information corresponds to an allowed location; or rejecting a request to resume the previously released connection if the location information does not correspond to an allowed location.

In certain examples, the method may further comprise verifying location information reported by the UE based on previously stored information.

In certain examples, verifying the location information may comprise: obtaining an estimate of the location of the UE based on the previously stored information; comparing the estimated location of the UE with the reported location of the UE; and verifying the reported location based on a result of the comparison.

In certain examples, the previously stored information may comprise information (e.g. UE context) indicating locations previously accessed by the UE.

In certain examples, the method may further comprise selectively performing the connection procedure for the UE based on the result of the verifying.

In certain examples, the location information may comprise information indicating one or more of: a cell; a tracking area, wherein a cell comprises one or more tracking areas; and a subarea of a tracking area, wherein a tracking area is divided into two or more sub-areas.

In certain examples, a sub-area may correspond to a fixed geographical area of a size configurable by the network, or a cell may be divided into N fixed geographical areas, and/or one or more tracking areas of a cell, and/or one or more sub-areas per tracking area may be pre-configured in a base station serving the cell.

In certain examples, the method may further comprise transmitting, from a base station to the UE, area information relating to tracking areas of a cell served by the base station and/or sub-areas per tracking area/cell.

In certain examples, the area information may be transmitted as one or more of: system information broadcast periodically or on request; and via signalling (e.g. RRC signalling) In certain examples, the area information may comprise one or more of: a list of one or more tracking areas (e.g. a list of one or more tracking area indices) included in a cell; a list of two or more sub-areas (e.g. a list of two or more area indices) included in a tracking area; coordinates of a reference sub-area of a tracking area; information relating to a radius of a tracking area; information relating to a radius of a sub-area; and information indicating a subarea mapping direction.

Certain examples of the present disclosure provide a first network entity (e.g. UE, base station, 30 AMF entity and/or UDM entity) configured to operate according to a method of any aspect, example, embodiment and/or claim disclosed herein.

Certain examples of the present disclosure provide a second network entity (e.g. UE, base station, AMF entity and/or UDM entity) configured to cooperate with a first network entity of the preceding example according to a method of any aspect, example, embodiment and/or claim disclosed herein.

Certain examples of the present disclosure provide a network (or wireless communication system) comprising one or more network entities (e.g. first and/or second network entities) according to the preceding examples.

Certain examples of the present disclosure provide a computer program comprising instructions which, when the program is executed by a computer or processor, cause the computer or processor to carry out a method according to any aspect, example, embodiment and/or claim disclosed herein.

Certain examples of the present disclosure provide a computer or processor-readable data carrier having stored thereon a computer program according to the preceding example.

Figure 9 is a block diagram of an exemplary network entity that may be used in examples of the present disclosure. For example, the UE, RAN, AMF, UDM and/or other NFs may be provided in the form of the network entity illustrated in Figure 9. The skilled person will appreciate that a network entity 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.

The entity 900 comprises a processor (or controller) 901, a transmitter 903 and a receiver 905.

The receiver 905 is configured for receiving one or more messages from one or more other network entities, for example as described above. The transmitter 903 is configured for transmitting one or more messages to one or more other network entities, for example as described above. The processor 901 is configured for performing one or more operations, for example according to the operations as described above.

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, example or claim 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.

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.

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, aspect and/or claim 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.

While the invention 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 invention, as defined by the appended claims.

Abbreviations/Definitions In the present disclosure, the following acronyms/definitions are used.

3GPP 3rd Generation Partnership Project 5G 5th Generation 5GC 5G Core AMF Access and Mobility Management Function AS Access Stratum CN Core Network GEO Geosynchronous Equatorial Orbit gNB 5G base station GNSS Global Navigation Satellite System HAPS High Altitude Platform Station IE Information Element MSG Message NAS Non Access Stratum NF Network Function NG interface between gNB and 5GC NG Next Generation NGAP NG Application Protocol NR New Radio NTN Non Terrestrial Network PLMN Public Land Mobile Network RAN Radio Access Network RRC Radio Resource Control SIB System Information Broadcast TA Tracking Area TAI Tracking Area Identity

TS Technical Specification

UDM Unified Data Management UE User Equipment WGS World Geodetic System Xn interface between two NG-RAN nodes

Claims

Claims 1. A method for reporting UE location information in a network (e.g. an NTN) comprising the UE and one or more network entities, the method comprising: receiving, by a first network entity, from the UE, location information of the UE; determining, by a second network entity, whether the location information corresponds to an allowed location (and/or a restricted location); and selectively performing a connection procedure for the UE based on the result of the determining.
2. A method according to claim 1, wherein the first network entity is a base station (e.g. NG-RAN node) and the location information is received in a first message (e.g. RRCSetupComplete) relating to initial access of the UE to the network, wherein the second network entity is an AMF entity selected by the first network entity based on the location information, and wherein the connection procedure comprises completion of a UE registration procedure.
3. A method according to claim 2, wherein the method further comprises: receiving, by the second network entity, from the first network entity, a second message (e.g. Initial UE message) including the location information; and receiving, by the second network entity, from a third network entity (e.g. UDM entity), a third message comprising a UE subscriber/information profile, wherein the second network entity determines whether the location information corresponds to an allowed location (and/or a restricted location) for the UE based on the received location information and information contained in the UE subscriber/information profile.
4. A method according to claim 2 or 3, wherein the method further comprises transmitting, from the second network entity to the first network entity, a list of allowed locations (and/or a list of restricted locations) for the UE.
5. A method according to claim 2, 3 or 4, wherein selectively performing the connection procedure comprises: completing a UE registration procedure if the location information corresponds to an allowed location; or rejecting the UE registration procedure if the location information does not correspond to an allowed location.
6. A method according to claim 1, wherein the first network entity is the same as the second network entity and is a base station (e.g. NG-RAN node), and the location information is received in a fourth message (e.g. RRCResumeRequest) relating to resuming a previously released connection of the UE to the network, wherein the first network entity determines whether the location information corresponds to an allowed location (and/or a restricted location) for the UE based on the received location information and a previously stored list of allowed locations (and/or a previously stored list of restricted locations) for the UE, and wherein the connection procedure comprises resuming the previously released connection of the UE to the network.
7. A method according to claim 6, wherein the method further comprises transmitting, from the first network entity to the UE, a list of allowed locations (and/or a list of restricted locations) for the UE.
8. A method according to claim 6 or 7, wherein selectively performing the connection procedure comprises: resuming the previously released connection of the UE to the network if the location information corresponds to an allowed location; or rejecting a request to resume the previously released connection if the location information does not correspond to an allowed location.
9. A method according to claim 6, 7 or 8, wherein the method further comprises verifying location information reported by the UE based on previously stored information.
10. A method according to claim 9, wherein verifying the location information comprises: obtaining an estimate of the location of the UE based on the previously stored information; comparing the estimated location of the UE with the reported location of the UE; and verifying the reported location based on a result of the comparison.
11. A method according to claim 9 or 10, wherein the previously stored information comprises information (e.g. UE context) indicating locations previously accessed by the UE.
12. A method according to claim 9, 10 or 11, wherein the method further comprises selectively performing the connection procedure for the UE based on the result of the verifying.
13. A method according to any preceding claim, wherein the location information comprises information indicating one or more of: a cell; a tracking area, wherein a cell comprises one or more tracking areas; and a sub-area of a tracking area, wherein a tracking area is divided into two or more sub-areas
14. A method according to claim 13, wherein a sub-area corresponds to a fixed geographical area of a size configurable by the network, or a cell is divided into N fixed geographical areas, and/or wherein one or more tracking areas of a cell, and/or one or more sub-areas per tracking area are pre-configured in a base station serving the cell.
15. A method according to claim 13 or 14, wherein the method further comprises transmitting, from a base station to the UE, area information relating to tracking areas of a cell served by the base station and/or sub-areas per tracking area/cell.
16. A method according to claim 15, wherein the area information is transmitted as one or more of: system information broadcast periodically or on request; and via signalling (e.g. RRC signalling)
17. A method according to claim 15 or 16, wherein the area information comprises one or more of: a list of one or more tracking areas (e.g. a list of one or more tracking area indices) included in a cell; a list of two or more sub-areas (e.g. a list of two or more area indices) included in a tracking area; coordinates of a reference sub-area of a tracking area; information relating to a radius of a tracking area; information relating to a radius of a sub-area; and information indicating a sub-area mapping direction.
18. A first network entity (e.g. UE, base station, AMF entity and/or UDM entity) configured to operate according to a method of any preceding claim.
19. A second network entity (e.g. UE, base station, AMF entity and/or UDM entity) configured to cooperate with a first network entity of claim 18 according to a method of any of claims 1 to 17.
20. A network (or wireless communication system) comprising one or more network entities according to claim 18 and/or claim 19.
21. A computer program comprising instructions which, when the program is executed by a computer or processor, cause the computer or processor to carry out a method according to any of claims 1 to 17.
22. A computer or processor-readable data carrier having stored thereon a computer program according to claim 21.