Method, user equipment, system or mobile communication network, program and computer-readable medium for operating a user equipment with a radio access network of a mobile communication network,

Abstract

The present invention relates to a method for operating a user equipment with a radio access network of a mobile communication network, in which the user equipment can be simultaneously connected to different mobile communication networks having or using different network identifier information, wherein such different mobile communication networks comprise a first mobile communication network and at least a second mobile communication network wherein the user equipment is able to register with the first mobile communication network using a first connection, and wherein the user equipment is further able to register with the at least second mobile communication network using a second connection, in order to use the user equipment with one or both of a first mobile communication network and / or a second mobile communication network, the method comprises the following steps:-in a first step, the user equipment transmits capability indication information, the capability indication information comprises at least one piece of information about whether the user equipment supports or is capable of establishing both a first connection and a second connection,-a second step of the user equipment receiving multiple registration information, the multiple registration information includes at least one piece of information regarding whether the user equipment is allowed to establish both the first connection and the second connection.

Description

BACKGROUND

[0001] The present invention relates to a method for operating a user equipment with a radio access network of a mobile communication network, wherein the user equipment is capable of connecting to different mobile communication networks with or using different network identifier information at the same time, wherein such different mobile communication networks comprise a first mobile communication network and at least a second mobile communication network, wherein the user equipment is capable of registering to the first mobile communication network using a first connection, and wherein the user equipment is further capable of registering to the at least second mobile communication network using a second connection.

[0002] Furthermore, the present invention relates to a user equipment for operating with a radio access network of a mobile communication network, wherein the user equipment is capable of connecting to different mobile communication networks with or using different network identifier information at the same time, wherein such different mobile communication networks comprise a first mobile communication network and at least a second mobile communication network, wherein the user equipment is capable of registering to the first mobile communication network using a first connection, and wherein the user equipment is further capable of registering to the at least second mobile communication network using a second connection.

[0003] Additionally, the present invention relates to a system or a mobile communication network for operating a user equipment with a radio access network of a mobile communication network, wherein the user equipment is capable of connecting to different mobile communication networks with or using different network identifier information at the same time.

[0004] Furthermore, the present invention relates to a program and a computer readable medium for operating a user equipment with a radio access network of a mobile communication network according to the method of the present invention.

[0005] In currently deployed mobile communication networks, a user equipment can be connected to different mobile communication networks independently, as well as to a single network using different access technologies at the same time (e.g. via or using 3GPP access and non-3GPP access at the same time). However, it is not possible to efficiently realize integrated connectivity via two different networks (also referred to as dual- or multiple-lead networks) at the same time.

[0006] Possible use cases include for example a user equipment being connected to a non-terrestrial network (e.g. a satellite-based network) and a terrestrial public land mobile network at the same time. Typically, such networks have (or use) different network identifiers, such as public land mobile network identifier information (PLMN ID) or a combination of a PLMN ID and a network identifier (NID). Furthermore, the user equipment should be capable of connecting to such different mobile communication networks at the same time using a single set of credentials. For example, the user equipment can be in its home mobile communication network (or home PLMN) at the same time, and be roaming in another mobile communication network at the same time.

[0007] However, for the following cases or scenarios, such dual booting can fail: - Some user equipment can support connectivity to multiple networks, while others do not; - Among the user equipment that support dual booting, there can be support for certain dual booting scenarios but not for others, there can be support for different numbers of simultaneous registrations, or a subscriber identity module (SIM card) or universal integrated circuit card can support only certain combinations of networks or scenarios for dual booting; - Even if a user equipment supports dual booting, there can be cases where a subscriber is not allowed to implement certain combinations, or the home network does not support such dual booting functionality, or in roaming cases, the visited network does not support such dual booting functionality, or, for the home network or the visited network, the network can not be able to implement certain combinations, e.g. due to regulatory requirements.

[0008] Therefore, even if in principle the dual booting functionality can be implemented, there are quite a number of technical problems and / or possible cases or scenarios, where such dual (or multi) booting and / or network connectivity cannot be effectively deployed. SUMMARY

[0009] It is an object of the present invention to provide a technically simple, efficient and cost-effective solution for operating a user equipment with a radio access network of a mobile communication network such that in cases where preconditions are met, the user equipment is not only able to connect to different mobile communication networks with or using different network identifier information simultaneously in theory but also in practice, and where in cases where such preconditions are not met, unnecessary attempts to implement or establish dual (or multi) booting can be avoided. It is a further object of the present invention to provide a corresponding user equipment, system or mobile communication network, as well as a corresponding program and computer readable medium.

[0010] The object of the present invention is achieved by a method for operating a user equipment with a radio access network of a mobile communication network, wherein the user equipment is able to connect to different mobile communication networks with or using different network identifier information simultaneously, wherein such different mobile communication networks comprise a first mobile communication network and at least a second mobile communication network, wherein the user equipment is able to register to the first mobile communication network using a first connection, and wherein the user equipment is further able to register to the at least second mobile communication network using a second connection, wherein, for using the user equipment with one or both of the first mobile communication network and / or the second mobile communication network, the method comprises the following steps: -- in a first step, the user equipment transmits capability indication information comprising at least one information about whether the user equipment supports or is capable of establishing both the first connection and the second connection, -- in a second step, the user equipment receives multiple registration information comprising at least one information about whether the user equipment is allowed to establish both the first connection and the second connection.

[0011] In particular, by means of the user equipment transmitting capability indication information and by the user equipment receiving multiple registration information, it is advantageously possible according to the present application that the involved entities are aware of the capabilities and / or limitations (regarding dual or multiple bootstrapping) of the respective other party, entity or network, such as to be able to use dual (or multiple) bootstrapping in practice and in practice where applicable, in particular where technically feasible and allowed - and as a result, also to be able to initiate such dual or multiple bootstrapping functionality efficiently where possible, and to avoid wasting network resources, energy and user equipment resources when trying to initiate dual or multiple bootstrapping where the respective conditions or requirements are not fulfilled. Thus, according to the present application, it is advantageously possible to provide a solution how dual and multiple bootstrapping can be applied in practice in an efficient manner (and, in particular, to try to apply such functionality only in situations where the prerequisites are actually fulfilled), and still to provide a backwards compatible solution, such that a mobile communication network can support newer user equipment supporting the capability as well as legacy user equipment (e.g. Release 18 and lower) not supporting the capability in general. Thus, according to the present application, it is advantageously possible to add such new functionality of dual and / or multiple bootstrapping to a mobile communication network in a backwards compatible manner, i.e. without consequences for legacy user equipment.

[0012] According to the present application, it is assumed that a user equipment operates with a radio access network of a mobile communication network. Furthermore, it is assumed that the user equipment is capable of connecting to different mobile communication networks at the same time with or using different network identifier information. In the context of the present application, such different mobile communication networks are referred to as a first mobile communication network and at least a second mobile communication network. The simultaneous connection of the (considered) user equipment to two different such mobile communication networks involves a so-called dual boot functionality, while the simultaneous connection of the (considered) user equipment to three (or even more) different such mobile communication networks involves a so-called multi-boot functionality. According to the present application, all practically conceivable solutions are solved, i.e. the use of two mobile communication networks, three mobile communication networks, four mobile communication networks, five mobile communication networks, etc. Thus, according to the present application, the (considered) user equipment is capable of registering to a first mobile communication network using a first connection and is also capable of registering to at least a second mobile communication network using a second connection. Of course, using a third connection, the (considered) user equipment can also register to a third mobile communication network. However, the use of such ordinal numbers (first mobile communication network, second mobile communication network, third mobile communication network or first connection, second connection, third connection) does not mean a priority or a priority order or whether one network has a different relative importance than another network, but is merely a means of distinguishing and differentiating between different mobile communication networks or connections: For example, using a "second connection" (to a second mobile communication network), the user equipment can exchange more data or more important or critical data, or be provided with more important or higher capacity communication services, respectively, than using a "first connection" and a first mobile communication network. However, chronologically, from a user equipment that has no connection at all to a user equipment that has both a first connection and a second connection established, there will usually be a first established connection and a later established further connection.

[0013] According to the present application, in order to be able to practically apply and use dual boot or multi-boot functionality in practice, it is proposed that the involved entities inform each other about the capabilities of the other entity, in particular by means of a user equipment, in a first step, typically towards a network node of a first mobile communication network or a second mobile communication network, transmits capability indication information (which includes at least one piece of information about whether the user equipment supports or is capable of establishing both a first connection and a second connection, i.e. supports dual boot functionality), and in a second step, the user equipment receives multiple registration information (which includes at least one piece of information about whether the user equipment is allowed to establish both a first connection and a second connection) from a network node of a first mobile communication network or a second mobile communication network, typically from one of the mobile communication networks whose network node the capability indication information was received from.

[0014] According to the present application, therefore, it is proposed to introduce a user equipment capability indication and network steering in order to include a dual / multi steering indication from a user equipment to the mobile communication network (to which the user equipment is connected); typically, the respective mobile communication network decides about which multiple access combinations are allowed for the requesting user equipment, in particular based on the (capability) indication (information) sent by the user equipment, the capabilities of the mobile communication network, the subscriber information (e.g. whether the subscriber is allowed and, if so, how dual / multi connectivity is to be performed), existing inter-network protocols and / or available connectivity as well as regulatory requirements (e.g. location). As a result thereof, the mobile communication network sends the allowed combinations (i.e. combination restrictions) to the user equipment (using multiple registration information) and the user equipment applies these combination restrictions when using multi-network connectivity. Furthermore, according to the present application it is proposed to forward such information or indication between networks, in particular in roaming scenarios.

[0015] In conventionally known telecommunication networks or mobile communication networks, use cases and scenarios for multi-connectivity of user equipment are known, e.g. in the following scenarios: - Dual 5G satellite access for autonomous ship operation: a user equipment on a ship is simultaneously connected to a 5G core mobile communication network via low earth orbit (LEO) satellites and medium earth orbit or geostationary orbit satellites, wherein traffic can be handed over due to a connection loss with the LEO satellite access network; - Intra-PLMN scenario: a user equipment in the coverage of two radio access networks or radio access technologies (RAN / RAT - e.g. New Radio, NR, and Long Term Evolution, LTE); - Dual steering involving two 3GPP networks, each using satellite access or unmanned aerial vehicle, UAV (e.g. airborne gNodeB), see TR 22.841, Figure 5 .9.1; - Intra-VPLMN scenario with home routed traffic, see TR 22.841, Figure 5 .12.1; - Intra-VPLMN scenario with local breakout, see TR 22.841, Figure 5 .12.2; - Inter-VPLMN scenario with home routed traffic, see TR 22.841, Figure 5 .12.3; - Inter-PLMN scenario with terrestrial and multiple non-terrestrial coverage, see TR 22.841, Figure 5 .14.1; - User equipment on an unmanned aerial vehicle using terrestrial and non-terrestrial network access, see TR 22.841, Figure 5.18.1.

[0016] According to the application, it is advantageously possible and preferred that, in a third step after the second step, the user equipment uses the first connection and the second connection and uses the set of credentials for simultaneously connecting to the first mobile communication network and to the second mobile communication network, wherein in particular, before the third step or after the third step and in particular repeatedly, conditions for using the first connection and the second connection are evaluated, wherein in particular, the evaluation is performed by the user equipment or by the first mobile communication network and / or by the second mobile communication network.

[0017] Thereby, the method of the application can advantageously be realized and implemented in a relatively simple and efficient manner.

[0018] According to the application, it is further advantageously possible and preferred that the set of credentials used by the user equipment relates to a single set of credentials for connecting to both the first mobile communication network and to the second mobile communication network, wherein the single set of credentials relates to the first mobile communication network or to the second mobile communication network or even to a third mobile communication network. Furthermore, it is further advantageously possible and preferred that, contrary to current multi-SIM functionality, when using more than one set of credentials, the network can control the multi-connectivity of the user equipment rather than having independent network connections.

[0019] Thereby, the method of the application can advantageously be realized and implemented in a relatively simple and efficient manner.

[0020] According to the application, it is further advantageously possible and preferred that the user equipment transmits the capability indication information according to one or more of the following possibilities, in particular as part of a registration request message: - to a radio access network to which the user equipment is connected; - to a core network corresponding to a radio access network to which the user equipment is connected; - to the first mobile communication network and / or to the second mobile communication network, and / or wherein the user equipment receives the multiple registration information according to one or more of the following possibilities, in particular as part of a registration accept message and / or as part of a UE configuration update, UCU, message and / or as part of a parameter update, PDU, message and / or as part of an access network discovery and selection policy, ANDSP, message and / or as part of a steering of roaming, SoR, message: - from a core network corresponding to a radio access network to which the user equipment is connected; - from the first mobile communication network and / or from the second mobile communication network.

[0021] Thereby, the method of the application can advantageously be implemented and performed in a relatively simple and efficient way.

[0022] According to the application, it is also advantageously possible and preferred that the user equipment transmits the capability indication information as part of at least one of: - a registration request message, - an access stratum communication between the user equipment and the radio access network - in particular as part of a UE radio capability handling, - a non-access stratum communication between the user equipment and the core network - in particular as part of a UE mobility management core network capability handling.

[0023] Thereby, the method of the application can advantageously be implemented and performed in a relatively simple and efficient way.

[0024] Further, according to the application, it is advantageously possible and preferred that the capability indication information comprises information about the first mobile communication network, in particular about the radio access network of the first network, when connected to the second network, and / or information informing the second network that it has been connected to the first network.

[0025] Thereby, the method of the application can advantageously be implemented and performed in a relatively simple and efficient way.

[0026] Further, according to the application, it is advantageously possible and preferred that the capability indication information comprises at least one of: - one information about whether the user equipment, a subscriber identity module of the user equipment and / or a universal integrated circuit card supports or is capable of establishing both the first connection and the second connection, - one information about how many multiple network registrations the user equipment is capable of supporting, in particular how many non-access stratum stacks and / or radio chains are capable of operating and / or instantiating, - one information about which combination of radio access technologies and / or frequency bands are supported, - one information about which core technology combination is supported, in particular a fifth generation core, 5GC, or an enhanced packet core, EPC, - one information whether the user equipment has been connected to a given network, if so, information related to the network, wherein, in particular, the capability indication information relates to a predefined table of capability types, each of such capability types being defined to comprise capability aspects about different capability dimensions.

[0027] Thereby, the method of the application can advantageously be realized and implemented in a relatively simple and efficient way.

[0028] Further, it is advantageously possible and preferred according to the application that the multiple registration information comprises, in addition to the one information on whether the user equipment is allowed to establish both the first connection and the second connection, at least one of the following: - one information on how many multiple network registrations the user equipment is allowed to maintain simultaneously or on how many mobile communication networks the user equipment is allowed to register to simultaneously, - one information on which access combinations the user equipment is allowed to implement, in particular on radio access technologies and / or frequency bands and / or on access to terrestrial or non-terrestrial networks, - one information on which networks and / or network combinations the user equipment is allowed to register to simultaneously, - one information on whether the user equipment needs to observe location and / or time conditions with respect to multiple registrations and / or one information on which location and / or time conditions the user equipment needs to observe with respect to multiple registrations.

[0029] Thereby, the method of the application can advantageously be realized and implemented in a relatively simple and efficient way.

[0030] Further, it is advantageously possible and preferred according to the application that, in a fourth step following the second step, the user equipment receives further multiple registration information, wherein the user equipment replaces the multiple registration information received in the second step by the further multiple registration information.

[0031] Thereby, the method of the application can advantageously be realized and implemented in a relatively simple and efficient way.

[0032] Thus, preferably, according to the application, further, it is advantageously possible and preferred according to the application that the network function capability indication information

[0033] - is communicated by a first network function or service of the mobile communication network, or

[0034] - is exchanged between a first network function or service and a second network function or service of the mobile communication network, wherein the network function capability indication information is in particular part of a profile information of the respective network function or service.

[0035] Thereby, the method of the application can advantageously be realized and implemented in a relatively simple and efficient way.

[0036] Moreover, it is advantageously possible and preferred according to the present application that in case of a roaming situation of the user equipment, it also comprises a similar roaming situation using a roaming architecture (e.g. using the roaming architecture for interconnecting between a PLMN and a SNPN), wherein the user equipment is connected to a visited mobile communication network - the capability indication information transmitted by the user equipment is received by the home mobile communication network of the user equipment in addition and, if applicable, also by one or more intermediate mobile communication networks of the visited mobile communication network and the home mobile communication network to which the user equipment is connected.

[0037] Thereby, the method of the present application can advantageously be implemented and carried out in a relatively simple and efficient manner.

[0038] Moreover, the present application relates to a mobile station for operating with a radio access network of a mobile communication network, wherein the user equipment is capable of being connected to different mobile communication networks having or using different network identifier information at the same time, wherein such different mobile communication networks comprise a first mobile communication network and at least a second mobile communication network, wherein the user equipment is capable of registering to the first mobile communication network using a first connection and wherein the user equipment is further capable of registering to the at least second mobile communication network using a second connection, wherein, for the user equipment to be used with the first mobile communication network and / or the second mobile communication network or both, the user equipment is configured so that: - the user equipment transmits capability indication information comprising at least one information about whether the user equipment supports or is capable of establishing both the first connection and the second connection, - the user equipment receives multiple registration information comprising at least one information about whether the user equipment is allowed to establish the first connection and the second connection.

[0039] Moreover, the present application relates to a system or a mobile communication network for operating a user equipment with a radio access network of a mobile communication network, wherein the user equipment is capable of being connected to different mobile communication networks having or using different network identifier information at the same time, wherein, for the system or the mobile communication network to be used with the user equipment as a first mobile communication network or a second mobile communication network of such different mobile communication networks, the user equipment is capable of registering to the mobile communication network as a first connection or a second connection, wherein a further connection is also enabled, the system or the mobile communication network is configured so that: - the system or the mobile communication network receives from the user equipment capability indication information comprising at least one information about whether the user equipment supports or is capable of establishing both the first connection and the second connection, -- the system or mobile communication network transmits multiple registration information to the user equipment, the multiple registration information comprising at least one information on whether the user equipment is allowed to establish both the first connection and the second connection.

[0040] Additionally, the present application relates to a program comprising computer readable program code which, when executed on a computer, and / or on a user equipment, and / or on a network node of a mobile communication network, or partially on a user equipment, and / or partially on a network node of a mobile communication network, causes the computer and / or the user equipment and / or the network node of the mobile communication network to perform the method according to the present application.

[0041] Yet additionally, the present application relates to a computer readable medium comprising instructions which, when executed on a computer, and / or on a user equipment, and / or on a network node of a mobile communication network, or partially on a user equipment, and / or partially on a network node of a mobile communication network, cause the computer and / or the user equipment and / or the network node of the mobile communication network to perform the method according to the present application.

[0042] These and other characteristics, features and advantages of the present application will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the application. This description is given for the sake of example and the details are not intended to limit the scope of the application. The reference figures quoted below refer to the attached drawings. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 A user equipment in a radio environment is schematically illustrated, such as to be potentially able to connect to different mobile communication networks, e.g. a terrestrial mobile communication network and a non-terrestrial mobile communication network.

[0044] Figure 2 A communication diagram schematically illustrating a user equipment transmitting capability indication information related to its capability to be simultaneously connected to different mobile communication networks, and the user equipment receiving multiple registration information related to whether the user equipment is allowed to establish certain connections.

[0045] Figure 3 And Figure 4 Also schematically illustrated is an example of a communication diagram of a user equipment transmitting capability indication information and the user equipment receiving multiple registration information, and how the resulting dual or multiple connectivity of the user equipment can be applied.

[0046] Figure 5 A communication diagram schematically illustrating a user equipment transmitting capability indication information and the user equipment receiving multiple registration information related to roaming or similar roaming situations of the user equipment (involving visited and home networks of the user equipment). Detailed Implementation

[0047] The invention will be described with respect to specific embodiments and with reference to certain accompanying drawings, but the invention is not limited thereto, but is defined only by the claims. The described drawings are merely illustrative and not restrictive. In the drawings, some elements may be enlarged and not drawn to scale for illustrative purposes.

[0048] Use the indefinite or definite article when referring to a singular noun. For example, unless otherwise specified, “one,” “a,” and “the” include the plural form of the noun.

[0049] Furthermore, the terms first, second, third, etc., used in the specification and claims are used to distinguish between similar elements and are not necessarily used to describe order or chronological sequence. It should be understood that such terms are interchangeable where appropriate, and the embodiments of the invention described herein can operate in an order different from that described or illustrated herein.

[0050] exist Figure 1 In the diagram, user equipment 20 is schematically shown in a radio environment so as to potentially connect to different mobile communication networks – Figure 1 The diagram exemplarily illustrates a terrestrial mobile communication network 100 and a non-terrestrial mobile communication network 200 – referred to in the context of this invention as a first mobile communication network 100 and a second mobile communication network 200. The first mobile communication network 100 includes an access network 100 or a radio access network 100 and a core network 120. The telecommunications network 100 or mobile communication network 100 is typically implemented as a cellular network or a cellular mobile communication network 100. The mobile communication network 100, particularly the core network 120, typically includes multiple network functions or services, which are not specifically indicated by reference numerals. The (radio) access network 110 includes multiple radio cells 11, 12, i.e., geographical areas served by base station entities, respectively. Figure 1 In the exemplary situation or scenario shown, the first base station entity 111 generates a first (terrestrial) radio cell 11 or is associated with or crosses the first (terrestrial) radio cell 11, and the second base station entity 112 generates a second (terrestrial) radio cell 12 or is associated with or crosses the second (terrestrial) radio cell 12 (in Figure 1In the middle, a first (terrestrial) radio cell 11, a second (terrestrial) radio cell 12 are represented by means of dashed circles around a first base station entity 111 and a second base station entity 112, respectively). The base station entities 111, 112 typically implement gNB functionality or next generation gNB functionality. The mobile communication network 100 is typically connected to a plurality of user equipment (or, alternatively, these user equipment are connected to the telecommunication network 100). Figure 1 Only one user equipment 20 is shown schematically, i.e. the case of the user equipment 20 is represented in the communication network 100, whose radio access network 110 (as mentioned above) is implemented as a terrestrial radio access network 110, i.e. the radio access network 110 implements a terrestrial radio access network (part) of the mobile communication network 100, which is able to provide radio access network functionality to the user equipment 20.

[0051] Figure 1 Additionally, a second mobile communication network 200 is shown in the form of a non-terrestrial network, i.e. comprising a non-terrestrial radio access network 230, which is preferably implemented according to the present application by means of (or as) a satellite radio access network or satellite non-terrestrial radio access network. The second mobile communication network 200 further comprises a (second) core network 220. The second mobile communication network 200 (shown exemplarily as a non-terrestrial mobile communication network) likewise comprises base station entities, which in Figure 1 In the middle, a first (terrestrial) radio cell 11, a second (terrestrial) radio cell 12 are represented by means of dashed circles around a first base station entity 111 and a second base station entity 112, respectively). The base station entities 111, 112 typically implement gNB functionality or next generation gNB functionality. The mobile communication network 100 is typically connected to a plurality of user equipment (or, alternatively, these user equipment are connected to the telecommunication network 100). Figure 1 In the middle, a first (terrestrial) radio cell 11, a second (terrestrial) radio cell 12 are represented by means of dashed circles around a first base station entity 111 and a second base station entity 112, respectively). The base station entities 111, 112 typically implement gNB functionality or next generation gNB functionality. The mobile communication network 100 is typically connected to a plurality of user equipment (or, alternatively, these user equipment are connected to the telecommunication network 100).

[0052] In any case, the user equipment 20 is able to be provided with radio access network functionality and network connectivity by the first mobile communication network 100 and by means of the second mobile communication network 200.

[0053] Thus, the user equipment 20 is shown schematically in a radio environment comprising a plurality of radio cells of a plurality of mobile communication networks 100, 200. Of course, in addition to the first mobile communication network 100, the second mobile communication network 200, an additional third mobile communication network or further mobile communication networks can be available to the user equipment 20.

[0054] In such cases of the user equipment 20, in conventionally known mobile communication networks, there is already the possibility for such user equipment 20 to be simultaneously connected to such different mobile communication networks 100, 200 via or using 3GPP access - also referred to as dual- or multi-boarding; such mobile communication networks 100, 200 typically have (or use) different network identifiers, such as Public Land Mobile Network Identifier information (PLMN ID) or a combination of PLMN ID and Network Identifier (NID). Moreover, the user equipment 20 should be able to connect to such different mobile communication networks 100, 200 simultaneously, preferably using a single set of credentials.

[0055] However, although such dual (or multi) boarding functionality is possible, in principle, there are quite a number of possible obstacles or technical problems and / or cases or scenarios, where such dual (or multi) boarding and / or network connectivity cannot be used at all, or at least not efficiently.

[0056] Such cases include cases where some user equipment supports connectivity to multiple networks (or dual-boarding) - while some user equipment does not support; for example, due to different modem support and / or ability to maintain more than one registration simultaneously. Moreover, within user equipment that supports dual-boarding, there can be support for some dual-boarding scenarios, but not others; for example, there can be support for dual-boarding in satellite / terrestrial scenarios, but not satellite / satellite scenarios (e.g. due to hardware limitations); or, there can be support for dual-boarding PLMN / PLMN scenarios, but not PLMN / SNPN (Stand-alone Non-Public Network) scenarios (e.g. due to lack of standalone non-public network support). Moreover, support for dual-boarding / multi-boarding can differ in the number of simultaneous registrations: for example, one user equipment supports two mobile communication networks, while another user equipment supports three mobile communication networks. Moreover, a subscriber identity module (SIM card) or universal integrated circuit card can only support certain combinations of networks or scenarios of dual-boarding, but not others; for example, due to inability to support multiple state machines for a single set of keys. Moreover, even in cases where user equipment supports dual-boarding in principle, there can be obstacles to its application, involving not allowing a subscriber to achieve certain combinations, or involving a home network not supporting dual-boarding functionality, or in cases of roaming, involving a visited or home network not supporting dual-boarding functionality (e.g. due to regulatory requirements for home or visited networks).

[0057] Thus, even if in principle the dual boot functionality could be implemented in a regular known mobile communication network, there remains a considerable number of technical problems and / or possible cases or scenarios, in which such dual boot (or multi boot) and / or corresponding network connectivity cannot be efficiently deployed, in particular due to somewhat hidden restrictions (restrictions to the application of dual boot or multi boot) to the entities that would be involved with such functionality.

[0058] According to the present application, it is proposed to provide the entities that are in communication (or cooperation) with each other with useful information in order to enable such dual boot / multi boot functionality, or rather to exchange such information between such entities. In particular, the present application aims at providing the mobile communication network 100, 200 (to which the considered user equipment 20 is connected or registered) with information about the capability of the considered user equipment 20 to connect to multiple networks. In addition, the mobile communication network 100, 200 should be provided with useful information from other sources about its own capability to support dual connectivity or multi connectivity. In addition, it is proposed to define the behavior of the mobile communication network 100, 200 and the answer or response towards the considered user equipment 20, as well as the behavior of the user equipment 20.

[0059] Thus, according to the present application, it is assumed that the user equipment 20 is capable of connecting to different mobile communication networks 100, 200 (such mobile communication networks 100, 200 have or use different network identifier information PLMN ID) at the same time. For using the user equipment 20 with one or both of the first mobile communication network 100 and / or the second mobile communication network 200, the user equipment 20 transmits capability indication information and receives multiple registration information, in particular in this order; however, according to further variants or embodiments of the present application, this order can also be reversed (i.e. the user equipment 20 first receives the multiple registration information and later transmits the capability indication information).

[0060] The capability indication information comprises at least one piece of information about whether the user equipment 20 supports or enables dual boot / multi boot (i.e. is capable of establishing both the first connection and the second connection), while the multiple registration information comprises at least one piece of information about whether the user equipment 20 is allowed to use dual boot / multi boot (i.e. to establish both the first connection and the second connection).

[0061] Generally, and as a result of the user equipment 20 transmitting the capability indication information and receiving the multiple registration information, in a subsequent third step, the dual boot or multi boot is actually implemented or carried out by means of the user equipment 20 using the first connection and the second connection and in particular using a set of credentials (in particular a single set of credentials) to simultaneously connect to both the first mobile communication network 100 and the second mobile communication network 200.

[0062] This is schematically shown in Figure 2 Fig. 1.Figure 2 The communication diagram illustrates the user equipment 20 transmitting capability indication information related to its capabilities (for dual / multi-boarding, or connecting simultaneously to different mobile communication networks 100, 200), and the user equipment (from the respective core network - in the exemplary representation of Figure 2 The exemplary representation of a first mobile communication network 100 and its core network 120 - or from the respective radio access network - again, in the exemplary representation of Figure 2 The exemplary representation of a first mobile communication network 100 and its radio access network 110, or more precisely, a base station entity 111 being part of the radio access network 110, receiving a communication diagram of multiple registration information (related to whether the user equipment 20 is allowed to establish certain connections).

[0063] In a first processing step 301, the user equipment 20 under consideration is aware of its (own, i.e. hardware-related or device-related or subscriber identity module card-related) capabilities regarding dual / multi-boarding functionality (in particular, its limitations regarding such capabilities). Thus, the (dual / multi-boarding) capabilities are known to the user equipment 20, e.g. the capabilities of the user equipment 20 can be limited by the hardware capabilities of the user equipment 20 (and the information is part of the user equipment 20 characteristics, e.g. set by the user equipment 20 vendor) or the capabilities of the SIM card (the user equipment 20 e.g. queries (previously) and thus is known to it) or the capabilities of the user equipment 20 are stored in a configuration parameter in the user equipment 20 and / or the SIM card, which is typically configured by the (home network) operator (again, the user equipment 20 e.g. queries (previously) and thus is known to it).

[0064] In a second processing step 302, the user equipment 20 transmits capability indication information to an entity or network node of the radio access network 110 and / or to an entity or network node of the core network 120; in Figure 2In the exemplary embodiment shown, such capability indication information is transmitted by the user equipment 20 as part of the registration request (message). Thus, in this exemplary embodiment, the user equipment 20 performs the registration request and includes the capability indication (information); in particular, two preferred placements of this capability indication (information) are considered (as it is important to indicate support on radio level (i.e. access stratum, AS communication between UE and RAN) as well as on non-access stratum, NAS level (between UE and CN)): user equipment radio capability handling (the user equipment radio capability information includes in particular information about the radio access technologies supported by the user equipment, e.g. power class, frequency bands, etc.) and user equipment mobility management core network capability handling (this user equipment mobility management core network capability is divided into S1 user equipment network capability (mainly for E-UTRAN access related core network parameters) and user equipment 5G mobility management core network capability (mainly including other user equipment capabilities for 5G core network or for interworking with EPS), and includes non-radio related capabilities, e.g. non-access stratum security algorithms, etc.).

[0065] In a third processing step 303, the user equipment 20 is registered, i.e. the user equipment registration procedure is performed mainly by the respective or related network functions or services of the core network, in particular the access and mobility management function AMF, the authentication server function AUSF and / or the unified data management function UDM. Thus, the core network 120 performs the user equipment registration as needed, and additionally assesses the support for simultaneous registration of a specific UE to multiple networks.

[0066] In a fourth processing step 304, the user equipment 20 receives multiple registration information from an entity or network node of the radio access network 110 and / or from an entity or network node of the core network 120; in Figure 2 In the exemplary embodiment shown, such multiple registration information is transmitted by the mobile communication network 100 as part of the registration accept (message). Thus, the core network 120 responds in the registration accept (message) including the dual registration information / multiple registration information, which includes whether and in which combination multiple simultaneous registrations are allowed.

[0067] Thus, in particular, the capability indication (information) is transmitted as part of the registration procedure, and this capability indication information includes an indication whether the user equipment 20 supports simultaneous registration to multiple networks, and if so, in which form the simultaneous registration to the multiple networks is supported - such simultaneous registration to multiple networks is typically done with (or using) a single set of credentials, as using multiple subscriber identity modules for registration to multiple networks independently would basically correspond to existing multi-SIM functionality.

[0068] After receiving the multiple registration information, the user equipment 20 is able to use the first connection and the second connection to connect to the first mobile communication network 100 and to the second mobile communication network 200 simultaneously, thereby implementing or performing the third step of the method of the present application.

[0069] In Figure 2 particular, it is exemplarily represented that the communication between the user equipment 20 and the first mobile communication network 100 (i.e. its radio access network 110 and / or its core network 120) in order for the user equipment 20 to transmit the capability indication information and to receive the multiple registration information is part of a registration procedure; however, as already stated, and since the use of the ordinal number with respect to the different mobile communication networks is merely a way to distinguish or differentiate these networks, the communication of the user equipment 20 can also be with the "second" mobile communication network 200 instead of the first mobile communication network. In any case, the content of the capability indication information and / or of the multiple registration information can be shared between the respective networks; alternatively or cumulatively, upon the user equipment 20 having transmitted the capability indication information and having received the multiple registration information from one of the networks, the corresponding communication - i.e. the transmission of (further) capability indication information and the reception of (further) multiple registration information; e.g. also as part of a registration procedure, e.g. as part of the third step according to the method of the present application - can also be performed by the other one of the involved mobile communication networks.

[0070] Thus, according to the present application, the user equipment 20 transmits the capability indication information according to one or more of the following possibilities, in particular as part of a registration request message: - to the radio access network to which the user equipment 20 is connected; - to the core network corresponding to the radio access network to which the user equipment 20 is connected; - to the first mobile communication network 100 and / or to the second mobile communication network 200, and / or the user equipment 20 receives the multiple registration information according to one or more of the following possibilities, in particular as part of a registration accept message, and / or as part of a UE configuration update, UCU, message, and / or as part of a parameter update, PUP, message, and / or as part of an access network discovery and selection policy, ANDSP, message and / or as part of a steering of roaming, SoR, message: - from the core network corresponding to the radio access network to which the user equipment 20 is connected; - from the first mobile communication network 100 and / or from the second mobile communication network 200, In particular, according to the application, it can be the case that the (further) capability indication information transmitted to the second mobile communication network 200 comprises information about the first mobile communication network 100, in particular about the radio access network of the first mobile communication network 100, when connected to the second mobile communication network 200, and / or information informing the second mobile communication network 200 that the user equipment 20 has been connected to the first mobile communication network 100.

[0071] Preferably, according to the application, the conditions for using the first connection and the second connection are evaluated (by the user equipment 20, or by the first mobile communication network 100 and / or the second mobile communication network 200, or by both the user equipment 20 and the first mobile communication network 100 and / or the second mobile communication network 200) before the third step (of the inventive method) or after the third step - and in particular repeatedly; i.e. in the case of a change (e.g. a change of location of the user equipment 20) affecting whether the respected conditions are met, the dual boot functionality or the multi-boot functionality can be changed (e.g. involving another mobile communication network) or stopped (i.e. the user equipment 20 will have only one connection, either the first connection or the second connection).

[0072] Moreover, according to the application, it is advantageously possible and preferred that, in a fourth step after the second step, the user equipment 20 receives a further multiple registration information, wherein the user equipment 20 replaces the multiple registration information received in the second step by (or with) this further multiple registration information; thus, this further multiple registration information can be considered as an updated version of the multiple registration information previously received by the user equipment 20.

[0073] According to the application, the information content of the capability indication information considered in the dual / multiple registration capability indication is in particular corresponding to at least one of: - whether dual / multiple network registration is supported, can be: without further specification (e.g. yes / no), or about the user equipment 20, or about the SIM card, - how many multiple network registrations are supported (e.g. 2, 3,...): the user equipment can be limited in how many non-access stratum stacks and / or radio chains it can operate / instantiate at the same time (as each non-access stratum connection requires an independent state machine involving aspects such as authentication, encryption, idle / inactive / connected state, paging, so multiple connections require instantiation of multiple protocol stack instances, which poses implementation challenges, in particular when involving embedded platforms such as SIM cards), - which access technologies and band combinations are supported (e.g. 4G, 5G, SNPN, LEO satellite, MEO satellite,...): the user equipment can be limited in hardware in terms of access technologies or combinations of bands (e.g. RF filters, power, frequency support) that it can operate in parallel, - which core technology combination is supported (e.g. 5GC, EPC): the user equipment can not be able to operate both 5G-NAS and 4G-NAS stacks simultaneously, - whether the user equipment 20 is already connected to a given network and, if so, information related to this network (in particular in order to not circumvent the conditions allowing the user equipment 20 to implement what network combination). It can also be that, if already connected to a given PLMN ID, the new network can select network functions or services having a direct connectivity to this PLMN ID (e.g. they are located in the same (cloud) zone).

[0074] In particular, it is advantageously possible according to the application that the user equipment 20 can use a predefined capability table instead of having to explicitly include each parameter, so that the signaling can be optimized and the scope simplified, e.g. “capability type-1” is equivalent to a specific combination of parameters.

[0075] Thus, in addition to information about whether the user equipment 20 supports or is able to establish both the first connection and the second connection, the capability indication information comprises at least one of: - one information about whether the user equipment 20, the subscriber identity module of the user equipment 20 and / or the universal integrated circuit card support or enable both the first connection and the second connection, - one information about how many multi-network registrations the user equipment 20 is able to support, in particular how many non-access stratum stacks and / or radio chains are able to operate and / or instantiate, - one information about which combination of radio access technologies and / or frequency bands is supported, - one information about which core technology combination is supported, in particular a fifth generation core 5GC or an enhanced packet core EPC, wherein, in particular, the capability indication information relates to a predefined capability type table, each of such capability types being defined to comprise capability aspects about different capability dimensions.

[0076] According to the application, the information content of the multiple registration information, or the information content considered in the dual / multiple registration information, in particular corresponds to at least one of: - whether the user equipment is allowed to register to multiple networks; - how many networks the user equipment is allowed to register to simultaneously; - which access combinations the user equipment is allowed to implement; -- which network combinations the user equipment 20 is allowed to implement (in a similar way to the carrier aggregation (CA) functionality, only certain specific frequency combinations are allowed (i.e. it is not possible to aggregate any frequency combination), according to the present application it is preferred which network combinations the user equipment 20 is able to use can be controlled (in particular by the home operator), i.e. the combination of specific "PLMN A and PLMN B" is restricted, even though this combination is possible / realizable from a technical point of view).

[0077] In order to meet regulatory requirements, the network can need to limit connectivity to multiple networks to certain locations (e.g. countries) and / or times. In order to implement such requirements, according to the present application it is proposed that -- the location and / or time conditions are included in the dual / multiple registration information, so that the information or the specific registration combination is only allowed if the condition(s) are met, and / or -- if it is detected that the conditions are not met (e.g. the user equipment moves from country A to country B), the configuration of this user equipment is updated.

[0078] Thus, in addition to the information about whether the user equipment 20 is allowed to establish both the first connection and the second connection, the multiple registration information also comprises at least one of: -- an information about how many multiple network registrations the user equipment 20 is allowed to maintain simultaneously or about how many mobile communication networks 100, 200 the user equipment 20 is allowed to register to simultaneously, -- an information about which access combinations the user equipment 20 is allowed to implement - in particular about radio access technologies and / or frequency bands and / or about accessing terrestrial or non-terrestrial networks, -- an information about which networks and / or network combinations the user equipment 20 is allowed to register to simultaneously, -- an information about whether the user equipment 20 needs to observe location and / or time conditions with regard to multiple registrations and / or an information about which location and / or time conditions the user equipment 20 needs to observe with regard to multiple registrations.

[0079] As already mentioned, the conditions for using the first connection and the second connection are evaluated before the third step (of the inventive method) or after the third step - and in particular repeatedly. In Figure 3 and Figure 4 possible and preferred implementations of such an update or evaluation of the conditions are schematically shown, which illustrate examples of a communication diagram of the user equipment 20 transmitting capability indication information to the mobile communication network 100 and the user equipment 20 receiving the multiple registration information, and how the resulting dual connection or multiple connection of the user equipment 20 can be applied: Figure 3 and Figure 4are each shown schematically as Figure 2 the second processing step 302 (i.e. the user equipment 20 transmits capability indication information, in particular as part of a registration request message, to an entity or network node of the radio access network 110 and / or to an entity or network node of the core network 120 of the mobile communication network 100) and the fourth processing step 304 (i.e. the user equipment 20 receives multiple registration information, in particular as part of a registration accept message, from an entity or network node of the radio access network 110 and / or from an entity or network node of the core network 120 of the mobile communication network 100) as indicated in the middle.

[0080] In the exemplary embodiment as indicated in the middle, in a fifth processing step 305 (after the fourth processing step 304), the user equipment 20 evaluates the (dual / multiple registration) conditions (UE-based condition evaluation of the dual / multiple registration information) received by means of the multiple registration information from the mobile communication network 100 and subsequently applies these conditions regarding the dual / multiple bootstrapping functionality, i.e. it is simultaneously connected to the first mobile communication network 100 and the second mobile communication network 200, in a sixth processing step 306, thus realizing or performing the third step of the inventive method according to the present application. Figure 3 In contrast thereto, in the exemplary embodiment as indicated in the middle, in a seventh processing step 307 (after the fourth processing step 304), the mobile communication network 100 evaluates the (dual / multiple registration) conditions (network-based condition update of the dual / multiple registration information) from both the capability indication information and the multiple registration information and subsequently, in an eighth processing step 308, sends configuration update information or a configuration update message to the user equipment 20, if applicable and necessary due to e.g. a change of the location of the user equipment 20, which configuration update information or configuration update message comprises the multiple registration information; thereafter, in a ninth processing step 309, the user equipment 20 re-applies the dual / multiple bootstrapping functionality according to the received condition or configuration update information or message, i.e. it is simultaneously connected to the first mobile communication network 100 and the second mobile communication network 200, thus realizing or performing the third step of the inventive method according to the present application.

[0081] Figure 4 According to the present application, and

[0082] the embodiments or variants mentioned in the middle can also be realized mixed or in parallel (or combined), i.e. the evaluation of the conditions to be observed regarding the dual / multiple bootstrapping can also be performed both by the user equipment 20 (e.g. regarding a part of such conditions) and by the mobile communication network 100 (e.g. regarding another part of such conditions). Figure 3 Figure 4 In the exemplary embodiment as indicated in the middle, in a fifth processing step 305 (after the fourth processing step 304), the user equipment 20 evaluates the (dual / multiple registration) conditions (UE-based condition evaluation of the dual / multiple registration information) received by means of the multiple registration information from the mobile communication network 100 and subsequently applies these conditions regarding the dual / multiple bootstrapping functionality, i.e. it is simultaneously connected to the first mobile communication network 100 and the second mobile communication network 200, in a sixth processing step 306, thus realizing or performing the third step of the inventive method according to the present application.

[0083] ​Moreover, according to the application, alternative ways of sending the dual / multiple registration information are possible and preferred; thus, in particular, the following forms are proposed, in which the dual / multiple registration information is communicated to the user equipment 20 as part of the registration procedure or due to network-triggered update of said information: - the multiple registration information can be included in the registration accept message (sent at the end of the registration procedure) or as part of the registration procedure; - the multiple registration information can be part of a user equipment configuration update, UCU, message (the user equipment configuration is updatable at any time by the network using a user equipment configuration update procedure, which in particular comprises: access and mobility management related parameters decided and provided by an access and mobility management function, AMF), i.e. in case the given UCU typically includes MM (mobility management) related information, the multiple registration information is conveyed from the AMF to the user equipment 20; - the multiple registration information can be part of a user equipment parameters update, UPU, message (the purpose of the control plane solution for updating user equipment parameters is to allow a home public land mobile network, HPLMN, a standalone non-public network, SNPN, or a credential holder, CH (of a standalone non-public network) to update the user equipment 20 with a specific set of parameters generated and stored in the unified data management, UDM, by delivering protected UDM update data via non-access stratum signaling; the HPLMN, SNPN or CH updates such parameters based on operator policy; the UDM update data delivered to the user equipment 20 by the UDM can for example include one or more user equipment parameters, including: (a) updated default configured NSSAI (the end consumer of the parameter is the ME); (b) updated routing indicator data (the end consumer of the parameter is the USIM when the relevant credentials are stored in the USIM, i.e. for PLMN or SNPN credentials, or the ME when the relevant credentials are stored in the ME, i.e. for SNPN credentials); (c) an indication of whether disaster roaming is enabled in the UE in case a UE MINT support indicator is received or the UE is currently registered for disaster roaming services; (d) an indication of the "applicability" of the "list of PLMNs to use in disaster conditions" provided by the VPLMN in case a UE MINT support indicator is received or the UE is currently registered for disaster roaming services; (e) a "request UE confirmation" indication, (f) a "request re-registration" indication), i.e. in case a change in subscriber-related information would allow the UDM to directly trigger an update (for which the UPU procedure would result) the multiple registration information is conveyed from the UDM to the user equipment 20 via the AMF as a transparent forwarder; -- this multiple registration information can be part of an Access Network Discovery and Selection Policy, ANDSP, message, i.e. this multiple registration information is transmitted from the PCF to the user equipment 20 via the AMF as a transparent forwarder, because the Access Network Discovery and Selection Policy information is intended to help the user equipment to select a WLAN access network, and therefore, according to embodiments of the application, can be extended at some point to other access networks (the Access Network Discovery and Selection Policy is an optional policy that can be provided by the network to the user equipment; in the current version of the present specification, this Access Network Discovery and Selection Policy should only include rules to help the UE to select a WLAN access network, and currently, no rules are specified for selecting other types of non-3GPP access networks); -- this multiple registration information can be part of a Roaming Guidance (SoR) message, i.e. this multiple registration information is transmitted from the AMF to the user equipment 20 (the SoR information for a given subscriber includes a list of preferred PLMN / access technology combinations and / or a priority list of credential holder controlled preferred SNPNs and GINs, or the HPLMN / credential holder indicates that there is no need to change the above-mentioned list(s) stored in the UE; optionally, an indication of acknowledgement of the UDM request to receive this information from the UE is included), because although what specific network the user equipment should connect to is out of scope, the allowed access technology combinations are in scope. The dual / multiple registration information can advantageously be included in this message because, eventually, the user equipment will need to combine both sets of information to perform network selection for any additional (second, third, etc.) network after the initial network selection to the first network.

[0084] Regarding the implementation or deployment of the dual / multiple guidance functionality, there can be constraints for the network / network components to support dual / multiple connectivity: To produce the dual / multiple registration information, the mobile communication network 100 should not only consider the (capability indication) information provided by the user equipment 20, but also its own capabilities. While the user equipment 20 can be able to support simultaneous registration in multiple networks, from the network side, the following limitations can exist: -- the UDM can not be able to support this capability (one of the functions of the UDM is to perform the service network function registration management of the UE (e.g. store the serving AMF of the user equipment, store the serving SMF of the PDU sessions of the UE); currently there is only one AMF, and the current UDM is not typically able to support multiple AMFs); -- similar situations can exist in the case of other network functions or services, such as: AUSF (authentication), CHF (charging) or PCF (policy).

[0085] Thus, in order for the mobile communication network 100 (e.g. the AMF) to evaluate whether all necessary NFs are capable, it is considered that the network function includes in its NF profile a dual / multiple registration capability indication (information) (the Network Repository Function, NRF, supports the functionality of service discovery of NRF services and their endpoint addresses through the NRF; the network function profile of the NF instance maintained in the NRF includes information related to the network function registering the profile) which is equivalent to the dual / multiple registration capability indication (information) of the user equipment 20.

[0086] According to the present application, it is preferred that at least the UDM, AUSF (in general, the "home network"; for standalone non-public networks, the term "Credential Holder (CH)" is used) in the (H-)PLMN will need to support the dual / multiple registration capability, while functionalities implementing the CH functionality (e.g. the UDM or the Authentication, Authorization and Accounting, AAA, system), the PCF will also need it in most cases.

[0087] Thus, in this way, the mobile communication network 100 is able to evaluate whether the (requesting) user equipment 20 can be provided with the capability (to deploy the dual / multi bootstrapping functionality) and, if the support is heterogeneous (e.g. there are several CHF instances and some of them support the feature while others do not), only the instances that support the feature are selected to serve the given (or requesting) user equipment 20.

[0088] Similarly, this information can be included in the subscriber data, such given network support, dual / multiple registration information can be directed by per-subscriber granularity.

[0089] Thus, preferably, according to the present application, within (or as part of) a mobile communication network, in particular its core network, comprising network functions or services, network function capability indication information

[0090] - is communicated by a first network function or service of the mobile communication network, or

[0091] - is exchanged between a first network function or service and a second network function or service of the mobile communication network, wherein the network function capability indication information is in particular part of the profile information of the respective network function or service.

[0092] In addition, other conditions are preferably taken into account, such as: - available connectivity, - existing roaming agreements, - regulatory framework applicability, which can be conditional on the location and / or time of the user equipment.

[0093] Figure 5 A communication diagram illustrating a roaming scenario is shown, which schematically illustrates the communication of the user equipment 20 transmitting capability indication information, and the user equipment 20 receiving multiple registration information related to the roaming situation of the user equipment 20 (involving the visited network 500 to which the user equipment 20 is connected and the home network 100 of the user equipment 20) to the visited network 500, to the home network 100 and / or to the intermediate network 400: in such roaming situations, i.e. typically when a user of a mobile communication network (i.e. home network) (e.g. the first mobile communication network 100) is served by a visited mobile communication network (e.g. the mobile communication network 500), the home network 100 is still responsible for authentication and authorization (the visited network 500 does not have user information or password keys linked to this user). Moreover, it can be the case that the two networks are not directly connected, but connected via one or more intermediaries (e.g. IPX and / or roaming hubs), hereinafter referred to as intermediate network 400.

[0094] To support roaming, the present invention, in particular the method of the present invention proposes that the dual / multiple registration capability (information) transmitted by the user equipment 20 is propagated so that it is known by the visited mobile communication network 500, the home mobile communication network 100 and / or the intermediate network 400, thus avoiding the following situations: - capability differences between the visited mobile communication network 500 and the home mobile communication network 100 can lead to the user equipment 20 receiving information about the support of the feature incorrectly; however, it does not actually work because neither the visited network 500 nor the home network 100 are aware of the capabilities of their counterpart. While the current visited mobile communication network 500 will not play a role in terms of dual / multiple registration capability, more complex scenarios will be possible, such as dual connectivity for services provided with a local breakout (LBO) architecture and additional network registration to LBO-based services in a visited network from another visited network, while the first visited network will need to support dual connectivity to be able to correctly direct policies in the second visited network.

[0095] - the intermediate network 400 will flag dual connectivity as fraudulent activity (e.g. SIM cloning) because it is not aware that a given user equipment 20 and / or network should be allowed to be registered multiple times.

[0096] Figure 5 All information flow directions are shown: - as part of a first processing step 311, the capability of the user equipment 20 is transmitted by the user equipment 20 by transmitting capability indication information to the visited network 500, and further to the intermediate network 400, and / or further to the home network 100; - as part of a second processing step 312, the capability of the visited network is transmitted to the intermediate network 400 and / or further to the home network 100; -- as part of the third processing step 313, transmitting the capabilities of the home network to the intermediate network 400 and / or further to the visited network 500; -- as part of the fourth processing step 314, transmitting the capabilities of the intermediate network to the home network 100 and / or to the visited network 500.

[0097] Thus, according to the present application - in case of roaming or similar roaming of the user equipment 20, wherein the user equipment 20 is connected to a visited mobile communication network - the capability indication information transmitted by the user equipment 20 is received not only by the home mobile communication network of the user equipment 20, but also by the visited mobile communication network of the user equipment 20 and, if applicable, also by one or more intermediate mobile communication networks of the visited mobile communication network and the home mobile communication network that are connecting the user equipment 20.

Claims

1. A method for operating a user equipment (20) together with a radio access network of a mobile communication network, wherein the user equipment (20) is capable of simultaneously connecting to different mobile communication networks having or using different network identifier information, Such different mobile communication networks include a first mobile communication network (100) and at least a second mobile communication network (200), wherein the user equipment (20) is capable of registering to the first mobile communication network (100) using a first connection, and wherein the user equipment (20) is further capable of registering to at least the second mobile communication network (200) using a second connection. in, In order to use the user equipment (20) with one or both of the first mobile communication network and / or the second mobile communication network (100, 200), the method includes the following steps: -- In the first step, the user equipment (20) transmits capability indication information, which includes at least one piece of information regarding whether the user equipment (20) supports or is capable of establishing both the first connection and the second connection. -- In the second step, the user equipment (20) receives multiple registration information, which includes at least one piece of information regarding whether the user equipment (20) is allowed to establish both the first connection and the second connection.

2. The method of claim 1, wherein in the third step following the second step, the user equipment (20) uses the first connection and the second connection and uses a set of credentials to simultaneously connect to the first mobile communication network and the second mobile communication network (100, 200). Specifically, the conditions for using the first connection and the second connection are evaluated either before or after the third step, and particularly repeatedly. Specifically, the assessment is performed by the user equipment (20) or by the first mobile communication network and / or the second mobile communication network (100, 200).

3. The method according to any of the preceding claims, wherein the set of credentials used by the user equipment (20) relates to a single set of credentials for connecting to both the first mobile communication network (100) and the second mobile communication network (200), wherein, The single set of credentials relates to the first mobile communication network (100), or the second mobile communication network (200), or even the third mobile communication network.

4. The method according to any of the preceding claims, wherein the user equipment (20) transmits the capability indication information according to one or more of the following possibilities, particularly as part of a registration request message: -- Transmitted to the radio access network to which the user equipment (20) is connected; -- Transmitted to the core network corresponding to the radio access network to which the user equipment (20) is connected; -- Transmitted to the first mobile communication network and / or the second mobile communication network (100, 200), and / or The user equipment (20) receives the multiple registration information according to one or more of the following possibilities, in particular as part of a registration acceptance message, and / or as part of a UE configuration update UCU message, and / or as part of a parameter update UPU message, and / or as part of an access network discovery and selection policy ANDSP message and / or as a roaming guidance SoR message: -- Received from the core network corresponding to the radio access network to which the user equipment (20) is connected; -- Received from the first mobile communication network and / or the second mobile communication network (100, 200).

5. The method according to any of the preceding claims, wherein the user equipment (20) transmits the capability indication information as part of at least one of the following: -- Registration request message -- Access layer communication between the user equipment (20) and the radio access network – particularly as part of the UE radio capability handling, -- Non-access stratum communication between the user equipment (20) and the core network – particularly as part of the handling of UE mobility management core network capabilities.

6. The method according to any of the preceding claims, wherein the capability indication information includes information about the first mobile communication network, particularly about the radio access network of the first network, when connected to the second network, and / or information notifying the second network that it has connected to the first network.

7. The method according to any of the preceding claims, wherein, in addition to information regarding whether the user equipment (20) supports or is capable of establishing both the first connection and the second connection, the capability indication information further includes at least one of the following: -- Information regarding whether the user equipment (20), the subscriber identity module and / or general-purpose integrated circuit card of the user equipment (20) support or are capable of establishing both the first connection and the second connection. -- Information regarding how many multiple network registrations the user equipment (20) can support, and in particular how many non-access stratum stacks and / or radio links it can operate and / or instantiate, -- A message regarding which radio access technologies and / or combinations of frequency bands are supported. -- A message regarding which core technology combination is supported, specifically the fifth-generation core 5GC or the enhanced group core EPC. -- Information on whether the user equipment (20) is connected to a given network, and if so, information related to the network. in, Specifically, the capability indication information relates to a predefined table of capability types, each of which is defined as including capability aspects related to different capability dimensions.

8. The method according to any of the preceding claims, wherein, in addition to information regarding whether the user equipment (20) is permitted to establish both the first connection and the second connection, the multiple registration information further includes at least one of the following: -- A message regarding how many multi-network registrations the user equipment (20) is allowed to maintain simultaneously or how many mobile communication networks (100, 200) the user equipment (20) is allowed to register to simultaneously. -- Information regarding which access combinations are permitted for the user equipment (20) – particularly regarding radio access technologies and / or frequency bands and / or access to terrestrial or non-terrestrial networks, -- A message regarding allowing the user equipment (20) to simultaneously register with networks and / or combinations of networks, -- Whether the user equipment (20) needs to observe a piece of information about the location and / or time conditions of multiple registrations and / or which location and / or time conditions the user equipment (20) needs to observe for multiple registrations.

9. The method according to any of the preceding claims, wherein in a fourth step following the second step, the user equipment (20) receives additional multi-registration information, wherein the user equipment (20) replaces the multi-registration information received in the second step with the additional multi-registration information.

10. The method according to any of the preceding claims, wherein – as part of a mobile communication network including network functions or services, particularly its core network, network function capability indication information -- Transmitted by a first network function or service of the mobile communication network, or -- Exchange between a first network function or service and a second network function or service in the mobile communication network. in, The network capability indication information is part of the profile information of the corresponding network function or service.

11. The method according to any of the preceding claims, wherein – in the case of roaming or similar roaming of the user equipment (20), wherein the user equipment (20) is connected to a visited mobile communication network – the capability indication information transmitted by the user equipment (20) is received not only by the home mobile communication network of the user equipment (20), but also by the visited mobile communication network of the user equipment (20), and, if applicable, by one or more intermediate mobile communication networks that are connecting the visited mobile communication network and the home mobile communication network of the user equipment (20).

12. A user equipment (20) for operation with a radio access network of a mobile communication network, wherein the user equipment (20) is capable of simultaneously connecting to different mobile communication networks having or using different network identifier information. Such different mobile communication networks include a first mobile communication network (100) and at least a second mobile communication network (200), wherein the user equipment (20) is capable of registering to the first mobile communication network (100) using a first connection, and wherein the user equipment (20) is further capable of registering to at least the second mobile communication network (200) using a second connection. in, In order for the user equipment (20) to be used with one or both of the first mobile communication network and / or the second mobile communication network (100, 200), the user equipment (20) is configured such that: -- The user equipment (20) transmits capability indication information, the capability indication information including at least one piece of information regarding whether the user equipment (20) supports or is capable of establishing both the first connection and the second connection. -- The user equipment (20) receives multiple registration information, which includes at least one piece of information regarding whether the user equipment (20) is allowed to establish both the first connection and the second connection.

13. A system or mobile communication network for operating a user equipment (20) together with a radio access network of a mobile communication network, wherein the user equipment (20) is capable of simultaneously connecting to different mobile communication networks having or using different network identifier information, in, In order to use the system or mobile communication network together with the user equipment (20) as a first mobile communication network (100) or a second mobile communication network (200) in such different mobile communication networks, the user equipment (20) can register to the mobile communication network as a first connection or a second connection, wherein additional connections are also enabled, and the system or the mobile communication network is configured such that: -- The system or mobile communication network receives capability indication information from the user equipment (20), the capability indication information including at least one piece of information regarding whether the user equipment (20) supports or is capable of establishing both the first connection and the second connection. -- The system or mobile communication network transmits multiple registration information to the user equipment (20), the multiple registration information including at least one piece of information regarding whether the user equipment (20) is allowed to establish both the first connection and the second connection.

14. A program comprising computer-readable program code, which, when executed on a computer and / or on a user equipment (20) and / or on a network node of a mobile communication network (100), or partially on the user equipment (20) and / or partially on a network node of the mobile communication network (100), causes the computer and / or the user equipment (20) and / or the network node of the mobile communication network (100) to perform the method according to any one of claims 1 to 11.

15. A computer-readable medium comprising instructions which, when executed on a computer and / or on a user equipment (20) and / or on a network node of a mobile communication network (100), or partially on the user equipment (20) and / or partially on a network node of the mobile communication network (100), cause the computer and / or the user equipment (20) and / or the network node of the mobile communication network (100) to perform the method according to any one of claims 1 to 11.

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