Method for connecting a terminal to a non-terrestrial access network

Abstract

The invention relates to a method for transmitting a connection policy relating to the linking of a terminal (UE, Pass), the policy comprising a connection characteristic of the terminal (UE, Pass) which is associated with at least one non-terrestrial access network (Sat1, Sat2, Sat3), the method being implemented in a control device (Disp) and comprising: the control device obtaining a parameter associated with a set of access devices (Sat1a, Sat1b, Sat2, Sat3a, Sat3b) of the at least one non-terrestrial access network (Sat1, Sat2, Sat3); obtaining a connectivity profile associated with the terminal (UE, Pass), the profile being determined from a context associated with the terminal (UE, Pass); transmitting the connection policy to the terminal, the policy being determined from the previously obtained parameter and connectivity profile, the connection policy being intended to be used by the terminal (UE, Pass) to connect to the at least one non-terrestrial access network (Sat1, Sat2, Sat3).

Description

Method of connecting a terminal to a non-terrestrial access network

[0001] The present disclosure belongs to the field of techniques for connecting to non-terrestrial access networks. More particularly, it allows a terminal to determine one or more non-terrestrial access networks to which a terminal connects based on criteria related to the terminal and the network.

[0002] A terminal, such as for example a smartphone, an IoT (Internet of Things) device, a residential gateway, can connect to various access networks alternatively or simultaneously. Thus, for example, a smartphone can attach to a 3G, 4G, 5G, xG mobile cellular network and / or attach to a Wi-Fi wireless network, whether public or private, accessible inside a building such as a residence, a train station, an airport, or accessible outside, such as in a city or a stadium. The terminal can also be connected to a wired network, which does not prevent it from connecting to one of the wireless networks indicated above. The terminal therefore has different connection options at a given time and known techniques, as described in the 3GPP TS 24.312 v17.0 document.0 of April 2012, therefore make it possible to inform the terminal about the different characteristics of these so-called terrestrial access networks. Using these characteristics, the terminal can select one or more access networks to which it connects to route the data of one or more applications active on the terminal or on equipment attached to this terminal, for example in a residential network. It can therefore be considered that the network assists the terminal in the process of selecting one or more access networks. Mobile cellular networks interconnect various types of networks based on different access technologies, equipment in this mobile network, such as, for example, a PCF (Policy Control Function) type device, can thus transmit an access policy comprising a list of access networks, information characterizing these networks or even an order of preference for connection to these access networks.

[0003] However, the known techniques of the prior art do not allow a terminal, firstly, to be informed about the non-terrestrial access networks to which it can connect and therefore to be able to determine or select one or more non-terrestrial access networks to which it can connect. We are indeed witnessing a development of this type of non-terrestrial networks offering data routing characteristics that are quite different depending in particular on the type of satellite orbit offering connectivity to the terminal. The terminal, faced with these new connection possibilities, complementary or alternative to the terrestrial access networks mentioned above, has no means of being able to select the access network best suited to its needs and, in a complementary manner, the connection options specific to types of terrestrial networks are not necessarily adapted to the characteristics of these so-called non-terrestrial networks.

[0004] The present invention aims to resolve all or part of the drawbacks mentioned above.

[0005] The present disclosure aims to remedy all or part of the limitations of the prior art solutions, in particular those set out above, by proposing a solution which makes it possible to inform a terminal about the characteristics of non-terrestrial communication networks and thus to be able to assist it in its connection procedure to one or more of these non-terrestrial communication networks.

[0006] To this end, a method is proposed for transmitting a connection policy relating to the attachment of a terminal, said policy comprising a connection characteristic of the terminal associated with at least one non-terrestrial access network, said method implemented in a control device and comprising - obtaining by the control device a parameter associated with a set of access equipment of the at least one non-terrestrial access network, - obtaining a connectivity profile associated with the terminal, said profile being determined from a context associated with said terminal, - transmitting to the terminal the connection policy, said policy being determined from the parameter and the connectivity profile obtained previously, the connection policy being intended to be used by the terminal to connect to the at least one non-terrestrial access network.

[0007] The method advantageously makes it possible to inform a terminal of the different options for connection to one or more non-terrestrial access networks, such as satellite networks or high-altitude platforms composed of balloons and / or drones. Indeed, non-terrestrial access networks, composed of a set of access equipment such as satellites, balloons or drones, are developing and differing in a non-exclusive manner according to their orbit or their altitude and it appears necessary to inform a terminal of the different possibilities by determining a connection policy, specific to the terminal and its context (use, location, environment, etc.), this policy including the different accessible non-terrestrial networks as well as information characterizing these networks.Thus, the terminal obtaining this policy determined by a control device, implemented for example in a network managed by an operator to which the terminal is subscribed, can select the network(s) best suited to its context of use, its location or its uses, or even to other information such as the applications active during the upcoming connection of the terminal. The determination method is suitable for various contexts including, but not limited to, a connection of a smartphone or an IoT device to a non-terrestrial network, a terminal wishing to communicate with another terminal (D2D context), a terminal offering connectivity to other terminals attached to it such as a residential gateway wishing to connect to a non-terrestrial access network.It should be noted that the determination process is dynamic and the determined policy can evolve over time, space and depending on the terminal that wishes to connect, in particular depending on the different situations indicated above.

[0008] In a particular embodiment, the connection policy comprises the at least one non-terrestrial access network with which a first priority information is associated, said first priority information being used by the terminal for the selection of one or more access networks to which the terminal transmits a connection request from among the at least one non-terrestrial access network.

[0009] The connection characteristic associated with a non-terrestrial access network can be very rich, and can for example include a significant amount of data characterizing the connection. It is therefore interesting to associate a priority level with each non-terrestrial access network of the policy, this priority being determined by the control device according to the different data of the characteristic, the terminal, a profile of the user of the terminal or even characteristics relating to one or more applications used. Thus, the process of selecting the terminal between the different non-terrestrial access networks is facilitated and accelerated, which can be important in the case of a handover of the terminal between two access networks.

[0010] In a particular embodiment, the connection policy further comprises a connection characteristic of the terminal associated with at least one terrestrial access network, and the method further comprises obtaining an attachment parameter to the at least one terrestrial network, said connectivity parameter to the at least one terrestrial network being further used to determine said connection policy.

[0011] The terminal may also find itself in a situation where possibilities of connection to a non-terrestrial network (satellite) and to a terrestrial network (cellular network, Wi-Fi network) coexist, in which case it is useful for the terminal to be informed of these different possibilities and for the connection policy to include both non-terrestrial networks and their connection characteristics as well as terrestrial networks and their characteristics.

[0012] According to a particular characteristic of this embodiment, the connection policy further comprises the at least one terrestrial access network with which a second priority information is associated, said first and second priority information being used by the terminal for the selection of one or more access networks to which the terminal transmits a connection request from among the at least one non-terrestrial access network and the at least one terrestrial access network.

[0013] In the case where the connection policy includes both terrestrial and non-terrestrial access networks, it is relevant to optimize the attachments for the terminal so that the different access networks are assigned a priority level, regardless of whether they are terrestrial or non-terrestrial.

[0014] In a particular embodiment, the parameter associated with the set of access equipment of the non-terrestrial network comprises a parameter for characterizing the orbit or altitude of the non-terrestrial network, the parameter being included in the following group: - A parameter associated with a low orbit, - A parameter associated with a medium orbit, - A parameter associated with a geostationary Earth orbit, - A parameter associated with a high altitude platform (HAP) orbit

[0015] When non-terrestrial networks, and more specifically satellite networks or HAP platforms, represent options for a terminal wishing to connect and access communication services (text, audio, video), the type of orbit, for example relative to the Earth, specific to the access network is particularly relevant. There are four main types of orbit (high, low, medium and geostationary) which have very different intrinsic characteristics in terms of latency, range and the possibility of remaining connected or not to the same satellite during a movement of the terminal. Depending on the context, and more precisely the location and needs of the terminal, one or other of these orbit options plays a major role in the prioritization of access networks and consequently in the selection of the network(s) by the terminal to establish a connection.A set of access equipment may correspond to a constellation if it involves satellite-type access equipment or to a platform if it involves balloons and / or drones of a HAP architecture.

[0016] In a particular embodiment, the transmission of the connection policy is transmitted via control equipment of a terrestrial or non-terrestrial access network.

[0017] It appears more optimized for a terminal to obtain policies from different equipment, for example specific to non-terrestrial access networks, and it is therefore more suitable and more economical in terms of network and terminal resources, for the terminal to obtain a policy from a single control device which will have obtained the different characteristics of the access and location networks of the terminal, other devices associated with the access networks and / or the access network operated by the operator with which the terminal has a subscription for example. The control device may for example be a PCF device of a cellular network to which the terminal is subscribed.

[0018] In a particular embodiment, the parameter associated with the set of access equipment comprises one or more parameters from the following group: - a transmission quality of the at least one non-terrestrial access network, - an availability of the non-terrestrial access network, - an estimation of the quality of service of the data transmission associated with the at least one non-terrestrial access network, - information on the load of the at least one non-terrestrial access network.

[0019] Non-terrestrial access networks can be advantageously characterized by various parameters including a transmission quality which can be expressed in relation to a signal-to-noise measurement in particular, an availability of the access network based on geographical data, an estimate of the quality of service indicating in particular the latency and / or a data throughput value. Information on the load, for example in number of terminals which can be connected simultaneously and / or a cumulative throughput value of the different connected terminals can also be used and transmitted to a terminal so that the latter selects the non-terrestrial access network.

[0020] In a particular embodiment, the connectivity profile associated with the terminal comprises one or more data from the following group: - an indication that the terminal is located inside a building, - a use of the terminal (D2D, FMC, IoT, broadband access) - at least one active application on the terminal, - an access technology of the terminal.

[0021] The connectivity profile of the terminal may advantageously include information indicating the connection context of the terminal and in particular whether the terminal is a gateway-type terminal capable of enabling the connection of other terminals to the non-terrestrial access network, whether the terminal wishes to communicate directly with another terminal or whether a smartphone-type terminal wishes to access a broadband application, for example. The connectivity profile may advantageously include one or more access technologies supported by the terminal, or even one or more protocols, or even information relating to one or more applications active on the terminal. This various information may thus make it possible to better adapt the determined non-terrestrial access network to the needs and / or characteristics of the terminal.

[0022] In a particular embodiment, the connection characteristic of the terminal associated with at least one non-terrestrial access network comprises one or more data from the following group: - a validity period of the transmitted policy, - a geographical indication of the transmitted policy, - quality of service data associated with the at least one non-terrestrial access network, - data on the entity responsible for managing the at least one non-terrestrial access network, - data associated with the authentication required for a connection to the at least one non-terrestrial access network, - data associated with the type of terminal.

[0023] The connection policy may be more or less complete and may include various information, including a validity period of the policy and / or a geographical indication informing a terminal about data in space and / or time of the policy allowing the terminal to be able to identify whether a received policy is suitable for movement and / or a duration of use of an application. Information on the authentication technique (required protocol, data to be transmitted), and / or data on the type of terminal for which the policy is valid is also important for the terminal to select and connect to an access network. Furthermore, the terminal, via the connection policy, may advantageously be notified of an entity in charge of managing the access network concerned by the policy, thus allowing it to request authentication, connection or even registration.

[0024] The various aspects of the transmission method just described can be implemented independently of each other or in combination with each other.

[0025] According to another aspect, the present disclosure relates to a method for connecting a terminal to at least one non-terrestrial access network, said method being implemented in the terminal prior to an attachment of the terminal to the at least one non-terrestrial access network, said method comprising - a reception from a control device of a connection policy, determined as a function of a parameter associated with the constellation of the at least one non-terrestrial access network and a connectivity profile of the terminal, said profile being determined from the location of the terminal, - a connection of the terminal to the at least one non-terrestrial access network in accordance with the received connection policy.

[0026] In a particular embodiment of this connection method, the connection policy further comprises a connection characteristic of the terminal associated with at least one terrestrial access network, the connection method being implemented in the terminal prior to an attachment of the terminal to the at least one non-terrestrial access network or to the at least one terrestrial network.

[0027] In another particular embodiment of this connection method, the method further comprises receiving a warning message relating to a delay in routing data from an active application, in the case where the terminal is attached to a non-terrestrial access network characterized by a transit time of a message between the terminal and access equipment of the non-terrestrial network greater than a threshold value.

[0028] In the case where the terminal connects to an access network involving significant latency, i.e. a transit time of a message between the terminal and a satellite or a balloon or a drone of the non-terrestrial network greater than a reference value, which is particularly the case in the case where a terminal connects to a geostationary satellite network, it may be advantageous to transmit a warning message to the terminal, or even to an active application of the terminal, therefore open or in operation, for example so that the user or the application does not disconnect when connecting the terminal to equipment due to the non-terrestrial network or while waiting for data from an application following the connection of the terminal.

[0029] In another particular embodiment of this connection method, the terminal simultaneously attaches to at least one non-terrestrial access network and at least one terrestrial access network via a proxy module, the proxy module adapting the routing of data from an active application according to the connection policy received.

[0030] In the case of a multiple connection, to a non-terrestrial access network and to a terrestrial access network, the terminal can advantageously connect via a proxy device, so that the latter adapts the routing of data from an application using the two connections according to the characteristics of the two connections, and so that the data is not, for example, delayed in time when it is received by the terminal.

[0031] In another particular embodiment of the connection method, the terminal implements congestion control of the connection established based on flow rate information associated with the at least one non-terrestrial access network received in the connection policy.

[0032] The terminal, based on flow rate information, implements congestion control allowing, for example, the adaptation of data transmission of an application based on flow rate information. Thus, the data of an application is transmitted in accordance with a flow rate value of a connection, which may vary from one access network to another.

[0033] The various aspects of the connection method just described can be implemented independently of each other or in combination with each other.

[0034] The invention also relates to a device for transmitting a connection policy relating to the attachment of a terminal, said policy comprising a connection characteristic of the terminal associated with at least one non-terrestrial access network, said device implemented in a control device further comprising a processor and a memory coupled to the processor with instructions intended to be executed by the processor for

[0035] - obtain by the control device a parameter associated with a set of access equipment of at least one non-terrestrial access network,

[0036] - obtaining a connectivity profile associated with the terminal, said profile being determined from a context associated with said terminal,- transmitting the connection policy to the terminal, said policy being determined from the parameter and the connectivity profile obtained previously, the connection policy being intended to be used by the terminal to connect to the at least one non-terrestrial access network.

[0037] This transmission device is capable of implementing in all its embodiments the transmission method which has just been described.

[0038] The invention also relates to a device for connecting a terminal to at least one non-terrestrial access network, said device being implemented in the terminal and further comprising a processor and a memory coupled to the processor with instructions intended to be executed by the processor for, prior to an attachment of the terminal to the at least one non-terrestrial access network: - receiving from a control device a connection policy, determined as a function of a parameter associated with a set of access equipment of the at least one non-terrestrial access network and a connectivity profile of the terminal, said profile being determined from a context associated with said terminal, - connecting the terminal to the at least one non-terrestrial access network in accordance with the received connection policy.

[0039] This connection device is capable of implementing in all its embodiments the connection method which has just been described.

[0040] The invention also relates to a system for transmitting a connection policy relating to the attachment of a terminal, said policy comprising a connection characteristic of the terminal associated with at least one non-terrestrial access network, said system comprising:- at least one transmission device described above,- at least one connection device also described above.

[0041] The invention also relates to computer program products comprising a set of program code instructions which, when executed by at least one processor, configure said at least one processor to implement the respective transmission and connection methods according to any of the embodiments of the present disclosure.

[0042] The invention also relates to a computer-readable recording medium having recorded thereon a set of program code instructions which, when executed by at least one processor, configure said at least one processor to implement a transmission method or a connection method according to any of the embodiments of the present disclosure.

[0043] The invention will be better understood upon reading the following description, given by way of non-limiting example, and made with reference to the figures which represent:is a schematic representation of a communication network comprising a plurality of terrestrial and non-terrestrial access networks,is a logical representation of a communication network in which the transmission method and the connection method are implemented according to one embodiment,is a representation of the attributes involved in a connection policy during an attachment of a terminal according to one embodiment,is a representation of the connection characteristics involved in a connection policy during an attachment of a terminal according to one embodiment,is a representation of a flowchart of a transmission method and a connection method according to one example,is a representation of a device for transmitting a connection policy according to an embodiment,is a representation of a terminal comprising a device for connecting a terminal according to an embodiment.,

[0044] In these figures, like references from one figure to another designate identical or similar elements. For reasons of clarity, the elements shown are not to scale, unless otherwise stated.

[0045] More generally, it should be noted that the methods of implementation and embodiment considered above have been described as non-limiting examples, and that other variants are consequently conceivable.

[0046] The technique described below overcomes some of the above-mentioned drawbacks.

[0047] In the remainder of the description, a communication network is presented comprising a plurality of access networks, terrestrial (Wi-Fi, fixed for example based on fiber access or xDSL (in English Digital Subscriber Line), cellular independently of the technology or version used (3G, 4G, 5G, xG) and / or non-terrestrial (for example satellite type).

[0048] We first refer to which presents a schematic representation of a communication network comprising a plurality of access networks. The communication network (Res) thus comprises an xG cellular access network which can be indifferently a 3G, 4G, 5G or later generation network. The communication network Res further comprises a Wi-Fi access network to which the terminal UE or Pass is likely to attach. In addition, the communication network comprises non-terrestrial access networks represented by the satellite constellations Sat1, composed of access equipment, in this case satellites, Sat1a and Sat1b, Sat2 and Sat3, composed of access equipment, in this case satellites, Sat3a and Sat3b. On the, the constellations, corresponding to the sets of access equipment, are represented by a single or two satellites to facilitate reading of the.Furthermore, three constellations Sat1, Sat2 and Sat3 are represented but it can be envisaged that only one, two or more than 3 constellations are included in the communication network Res. Furthermore, it should be noted that terrestrial accesses (xG, Wi-Fi) are optional and that the UE or Pass terminal can benefit from the transmission method with only the non-terrestrial access networks Sat1, Sat2, Sat3. It should be noted that according to another example, the non-terrestrial accesses are networks of balloons or drones, and according to this example the sets of access equipment are not strictly speaking constellations but networks and the access equipment are balloons and / or drones, this set being able to correspond to high altitude platforms (HAP).

[0049] The UE, Pass terminal may be a smartphone or IoT type terminal or even an access gateway to a residential or professional local network, also called a box. The UE, Pass terminal may include interfaces allowing it to attach to one of the xG, Wi-Fi, Sat1, Sat2, Sat3 access networks or may itself be connected to a device comprising an interface compatible with one or more xG, Wi-Fi, Sat1, Sat2, Sat3 access networks such as a modem. The UE, Pass terminal obtains a connection policy including for example an order of priority of the xG, Wi-Fi, Sat1, Sat2, Sat3 access networks, thus informing the UE, Pass terminal about the access network(s) to which the UE, Pass terminal should attach as a priority. The UE terminal, Pass can further attach to one or more access networks simultaneously among the xG, Wi-Fi, Sat1, Sat2, Sat3 access networks.The Disp device transmitting the connection policy to the terminal may, for example, be included in a PCF (Policy Control Function) type device informing the UE terminal, PAss, about the connection policy allowing it to attach to one or more of the xG, Wi-Fi, Sat1, Sat2, Sat3 access networks. Or, this Disp device may be included in an autoconfiguration server (ACS) type device informing the UE terminal, Pass of the connection configurations allowing it to attach to one or more of the xG, Wi-Fi, Sat1, Sat2, Sat3 access networks, for example by enriching the data model https: / cwmp-data-models.broadband-forum.org / used by the TR069 protocol https: / www.broadband-forum.org / download / TR-069.pdf.

[0050] Reference is then made to the which describes a logical representation of a communication network in which the transmission method and the connection method are implemented according to one embodiment. It is considered in this that the communication network comprises the xG, Wi-Fi, Sat1, Sat2, Sat3 access networks described in the and not shown in the.

[0051] Initially, a Satco (Satellite connectivity) device updates a Sorat (Steering Of Radio Access Technology) device corresponding in this example to the Disp device of the, included in a control device, and transmits for example in a P1 message information for updating the satellite context of a terminal, such as the UE terminal, Pass presented in the. It can thus transmit parameters characterizing the constellation(s) associated with the satellite access or accesses. Thus one of these parameters indicates whether the constellation is associated with a low Earth orbit, a medium Earth orbit, a high Earth orbit or geostationary orbit or a high altitude platform orbit (HAP).The Satco device may transmit the parameters associated with one or more constellations or each satellite access network may comprise a Satco device informing the Sorat device of the parameters concerning its own constellation. It should be noted that the Sorat device, according to one example, is included in a PCF device, as described in the. The Satco device may further transmit parameters relating to the connectivity provided by a satellite of the constellation, such as throughput and latency information, this information may further be associated with temporal information. For example, the parameters relating to connectivity may be transmitted according to a schedule, the throughput and / or latency values ​​may evolve in time and space depending on the position of the satellite of the constellation.The parameters transmitted by the Satco device may further comprise satellite profiles associated with the terminal or the user, corresponding for example to types of access to a constellation depending for example on a subscription taken out by the user of the terminal. The P1 message may also be transmitted by the Satco device to the Sorat device via an interfacing device of the Sorat device of the communication network with external entities, such as the Satco device, this interfacing equipment being for example an NEF (Network Exposure Function) type device not shown in the figure.

[0052] In the case where terrestrial networks are also accessible by the terminal and these terrestrial networks are part of the connection policy that will be transmitted to the terminal, devices NWDAF1 and NWDAF2 (in English network data analytics function) transmit in a P2 message attachment parameters to the terrestrial networks for which the devices NWDAF1 and NWDAF2 ensure the management of these attachment parameters. According to an example, the device NWDAF1 transmits attachment parameters associated with an xG type cellular network and the device NWDAF2 transmits attachment parameters associated with a Wi-Fi type network. The parameters include load statistics, predictions on the radio quality of the access network, transmission quality such as throughput information, latency information proposed by the access network.These parameters may also include data specific to the terminal, such as its behavior and in particular its movement, its presence inside or outside a building, the bandwidth used by the terminal's applications, this information being able to be obtained by the NWDAF1 / NWDAF2 device from the terminal itself or from a communication network management device.

[0053] The Sorat device also obtains in a P3 message data relating to the terminal to which a connection policy will be determined and transmitted. The P3 message is transmitted by a UDM (Unified Data Management) type device and the data includes information relating to the terminal such as the subscription associated with the terminal, the type of terminal or even intrinsic capabilities of the terminal such as the available communications interfaces and the possibility of routing data on at least two accesses simultaneously. The information obtained in the P2 and P3 messages, or even certain information from the P1 message, allows the Sorat device to establish a connectivity profile determined from the location of the terminal.

[0054] From this connectivity profile and the parameters associated with the constellations of non-terrestrial accesses, the Sorat device determines a connection policy for the terminal, used by the UE terminal, upon receipt of this policy, to attach or connect to one or more of the access networks considered in the connection profile. If the access networks are only non-terrestrial, the connection policy includes a ranking of these non-terrestrial access networks, to which the UE terminal must attach as a priority. In the case where the access networks are partly terrestrial networks, as in the, the connection policy will include an order of priority of the terrestrial networks and an order of priority of the non-terrestrial networks to which the terminal must attach.Alternatively, the order of priority for terrestrial networks and non-terrestrial networks is unique and the different networks, regardless of whether they are terrestrial or non-terrestrial, are ranked according to a single order of priority.

[0055] The connection policy is, for example, established based on information on flow rate, latency or even security or guarantee of the announced flow rate, as well as on the behavior of the terminal (mobility and speed of movement) and its location inside or outside a building in particular, this information being obtained in the respective messages P2 and P3.

[0056] The Sorat device then transmits the determined connection policy to the terminal in a P4 message. This connection policy is transmitted directly to the terminal or via another control device, such as a PCF type device. According to an alternative, the Sorat device is instantiated in the PCF device and it is considered that the Sorat device, independently of the embodiment, corresponds to a device for transmitting the connection policy relating to the attachment of the terminal. The P5 message can be transmitted via the user plane of the communication network, for example via the UPF (User Plane Function) gateway and a RAN (Radio Access Networks) access network to the UE terminal. The access network used to transmit the P5 message can be included in the access networks of the connection policy or be a separate access network.It should be noted that the UE terminal, when it receives the connection policy, may already include an active application and transmit and receive data for this application, the connection policy being able to indicate to it, for example, to modify its connection for the transmission of data of the active application. In the case where the Sorat device is included in the PCF device, then the PCF transmits the P4 message to the terminal and may, for example, transmit the connection policy in the control plane and, for example, use the ANDSF techniques if the RAN access network used to transmit the P5 message is an xG cellular network, in accordance with the 3GPP TS 23.412 v17.0.0 specification of April 2022, an update of which, in accordance with the invention, is presented in Figures 3 and 4.

[0057] Thus, in the, the policy or ISMP (in English Inter System Mobility Policy) is updated in accordance with the content of the invention and in particular figures 1 and 2. Lane represents only one example of update but other updates of the data structure presented in paragraph 4.2.2 of the 3GPP document cited above are possible. This involves updating the ISMP policy by integrating the non-terrestrial accesses and in particular by indicating the types of constellations of the different accessible non-terrestrial access networks. According to this example, four types of constellations are added: LEO (in English Low Earth Orbit), MEO (Medium Earth Orbit), GEO (in English geostationary orbit) and HAP (in English High altitude platform). This distinction is useful for better associating the selection of one of the non-terrestrial access networks and their associated orbit with the needs of the UE terminal, and in particular the needs of one or more applications of the UE terminal.Indeed, the characteristics of latency, instability due to interference associated with the different orbits but also the necessary changes of satellites during the movement of the terminal for example. It therefore appears relevant to distinguish the different constellations available as non-terrestrial access networks and to include them in a connection policy, so as to allow attachment of the terminal to a satellite of a constellation most suited to the needs of the UE terminal at a given time and at a given location and in accordance with the movement and location characteristics of the UE terminal.

[0058] Correspondingly, in the, the validity parameters of the different terrestrial and non-terrestrial access networks are also updated by incorporating the different non-terrestrial networks and more particularly the orbit types of the satellite networks so as to enrich the attachment possibilities of the UE terminal by integrating the non-terrestrial networks. This enriched validity information can be advantageously transmitted in the ANDSF messages transmitted to the UE terminal. In addition, the validity conditions of each non-terrestrial network can be described in a structure such as that described in section 4.2.16 of the 3GPP 24.312 document, thus making it possible to describe the validity conditions of each non-terrestrial network, identified by its orbit type, used to enrich the connection policy in accordance with the information structures notably described in the set.It should be noted that these data structures can be used when the available access networks are only of non-terrestrial types, the information relating to terrestrial networks being in this case not available and therefore not integrated into the determination of the connection policy.

[0059] Thus, in the, thanks to the received connection policy, the UE terminal sends an attachment request, not shown in the), to one or more access networks indicated and possibly classified in the connection policy. Depending on the case, this may be the access network(s) having a higher priority order or the access networks only indicated in the connection policy. If the connection policy only includes non-terrestrial access networks, this is one or more access networks identified for example by their orbits. In the case where the connection policy includes one or more terrestrial networks and one or more non-terrestrial networks, the terminal can attach to one or more of the indicated terrestrial networks and / or to one or more indicated non-terrestrial networks, for example in accordance with an indicated priority order.The terminal, depending on its location, the time it attaches, the threshold for receiving information from the various available access networks and depending on the connection policy received and its connectivity profile established in particular from its location, issues a request for attachment or connection to one or more of the access networks indicated in the connection policy.

[0060] The Sorat device, possibly via the PCF, further transmits the connection policy to one or more terrestrial access networks concerned by the connection policy. This thus allows in particular the terrestrial access network, and more particularly a control device of this access network, to control an attachment request from the UE terminal sent to the access network.

[0061] According to an example, the Sorat device further transmits the connection policy to the Satco device in a P5 message, in return for the parameters transmitted by the latter. From this received policy, the Satco device informs the non-terrestrial access networks so as to be able to control access of the UE terminal to a non-terrestrial network concerned by the connection policy. This connection policy can also be transmitted directly by the Sorat device to equipment in the control plane of a non-terrestrial access network.

[0062] Reference is then made to which describes a representation of a flowchart of a transmission method and a connection method according to an example.

[0063] It is considered in this embodiment that the communication network comprises terrestrial access networks and non-terrestrial access networks in accordance with the communication network described in the.

[0064] In a step 100, a communication network control device, comprising a device for transmitting a connection policy, obtains a set of parameters associated with each non-terrestrial network to which a terminal can possibly attach. For example, the terminal has subscribed to an operator managing a variety of terrestrial and non-terrestrial networks or having roaming agreements with other operators. The control device obtains, during the messages P1 and P2 described in the parameters associated with the different access networks managed by this operator or the operator with which an agreement exists. These parameters include parameters associated with the constellations of the non-terrestrial networks as well as parameters for attachment to one or more terrestrial networks.

[0065] The various steps could also be implemented in a situation where only non-terrestrial access networks are accessible, the difference in this case being to restrict the terminal's attachment options to these non-terrestrial networks.

[0066] The parameters associated with the constellations of non-terrestrial networks are for example a parameter associated with a low Earth orbit (LEO), a parameter associated with a medium Earth orbit (MEO), a parameter associated with a geostationary Earth orbit (GEO), a parameter associated with a high altitude platform orbit (HAP), the parameter being able to correspond to the abbreviations indicated for these different constellations and possibly an indication on the operator managing the network considered.The parameter associated with the constellation may further comprise, as an alternative or in addition to the above information: - a transmission quality of the non-terrestrial access network, expressed for example by an average and / or maximum throughput, - an availability of the non-terrestrial access network, for example based on a map, - an estimate of the quality of service of a data transmission associated with the non-terrestrial access network, for example expressed in routing delay, in latency and / or in number of elementary information items lost compared to a number of items of information transmitted, - information on the load of the non-terrestrial access network, corresponding for example to a number of attached terminals, to a total volume of data routed, to a percentage of transmission means used for data transmission.

[0067] Correspondingly, the parameters for attachment to one or more terrestrial networks correspond to the parameters associated with the constellations indicated above, except for the constellation-specific parameters, which are not applicable to terrestrial networks. The throughput and latency values ​​are also quite different depending on the terrestrial and non-terrestrial character, justifying the association of the received data with the terrestrial and non-terrestrial characters. The parameters associated with terrestrial networks are also known and described in particular in the 3GPP 24.312 v17.0.0 specification (April 2022)

[0068] During a step 101, the control device further obtains a connectivity profile associated with the terminal. This connectivity profile is for example obtained in a P3 message, possibly in addition to information transmitted in the P2 messages, as described in the.This connectivity profile includes, for example, an identifier of the terminal and further includes an indication that the terminal is located inside or outside a building, such as binary information indicating one or other of the possibilities, a use of the terminal which may correspond to a device-to-device (D2D) use, the possibility that a terminal may simultaneously be attached to a fixed network and to a mobile network, terrestrial and / or non-terrestrial, and information which may indicate that the terminal is a gateway as described therein, or that it is a terminal used for so-called IoT (Internet Of Things) applications such as, for example, a sensor, or that it is a terminal used for broadband access, such as a smartphone.It may further be envisaged that the terminal is more precisely described and determines the type or brand of smartphone or even, for example, that the terminal corresponds to a vehicle or a drone according to one example. The connectivity profile further or alternatively includes an active application on the terminal, this information for example indicated in the form of an application identifier or transport protocol number. This information may be used so that the terminal attaches to an access network most compatible with the characteristics of the application. The connectivity profile may further include an access technology supported by the terminal, naturally impacting the order of priority of the access networks in the connection profile to be determined and transmitted to the terminal.This connectivity profile can be established from information transmitted by the terminal, or transmitted by equipment in the communication network managing the terminals (UDM), an application entity or management equipment or access equipment.

[0069] In a step 102, the control device determines a connection policy adapted to the terminal, from the information obtained during steps 100 and 101, and in particular the set of parameters associated with each non-terrestrial network, possibly the parameters for attachment to one or more terrestrial networks and also according to the connectivity profile. The connection policy comprises the access networks to which the terminal can attach and possibly an order of priority of these networks, thus informing the terminal about the access networks classified according to whether they are better suited or not for attachment of the terminal. The connection policy also advantageously comprises connection characteristics associated with the connection policy.The policy may thus comprise one or more of the following characteristics, including a validity period of the transmitted connection policy, for example expressed in seconds, or a geographical indication of the transmitted policy, expressed for example in GPS data and corresponding to a valid geographical area for the connection policy, and which the terminal may exploit according to its own location when it attaches. The policy may also comprise quality of service data associated with the non-terrestrial access networks, thus making it possible to inform the terminal about the performance of the non-terrestrial networks to which it is likely to attach.The policy may further comprise data on the entity responsible for managing the at least one non-terrestrial access network, thus enabling the terminal to request it to register, issue its connection request or obtain additional data not available in the policy. The policy may comprise data associated with the authentication required for a connection to the at least one non-terrestrial access network, enabling the terminal to determine whether it can actually attach while respecting the constraints of the access network included in the policy or whether it must first, for example, obtain an authentication protocol required to attach to it. The policy may comprise data associated with the type of terminal, enabling the terminal wishing to attach to identify whether one of the access networks is particularly suited to its type.This could be the case, for example, of an IoT terminal requiring low throughput but also low latency and selecting a low orbit access network rather than a geostationary constellation access network.

[0070] In a step 103, the control device transmits in a P4 message to the terminal the connection policy determined in step 102. In the case where the control device is distinct from a PCF device and one of the terrestrial access networks is an xG network, the control device can transmit the connection policy via the PCF in accordance with the sending of an ANDSF policy known according to the prior art technique. Also, the control device can also be co-located with an ANDSF server and the connection policy can be transmitted via a 3GPP S14 interface to the terminal, allowing the terminal to attach itself to an access network distinct from the access network to which it is attached upon receipt of the policy or to remain attached to this network if the policy rather favors the preservation of an attachment to this access network.

[0071] Different situations are likely to occur depending on whether the connection policy includes only non-terrestrial access networks in particular. In this case, the control device possibly including a Sorat type device described in the, sends the connection policy to one or more non-terrestrial networks to the terminal, this policy being able to be transmitted via a PCF via an xG or Wi-Fi network or even a fixed network if the terminal is connected to one of these networks when receiving the policy.

[0072] In the alternative case where a multiple connection to a terrestrial network, and to a non-terrestrial network or to two terrestrial or non-terrestrial networks is possible, this multiple connection being based for example on the MPTCP (in English MultipathTCP) or MPQuic (in English MultipathQuic) protocol, and entered in the connection policy, the control device can further update the convergence module of the transport layer to take into account such multiple connectivity present in the connection policy.

[0073] In the alternative case where a non-terrestrial access network is used as backup for a terrestrial network, for example a fixed network, then the control device transmits the connection policy to an ACS server (autoconfiguration server), in charge of configuring the terminal, this configuration taking advantage of the connection policy. The terminal, corresponding to a gateway of a residential or business network in this case, will thus have knowledge of the different accessible constellations as well as the information linked to these constellations, and will be able to connect as quickly as possible to a satellite of a constellation when a connection is changed or added.

[0074] In the alternative case where the terminal is a terminal using D2D services, the control device transmits a connection policy allowing to activate and control a ProSE (Proximity Services) connectivity. Thus the terminal can select an access technology according to its location, a schedule, a reception threshold or other characteristics allowing to authorize and control D2D connectivities via a satellite connection.

[0075] In a step 104, upon receipt of the policy, the terminal receiving the policy determines to which non-terrestrial network, and / or possibly to which terrestrial network, the terminal must connect. It may be that the terminal is already connected to it, in which case a connection request is not required. If the connection policy indicates that the terminal should attach to another access network, as an alternative or in addition to the active connection, then the terminal transmits a new attachment request to one of the access networks included in the connection policy, placed as a priority in the policy and in accordance with the characteristics of the policy received.The terminal can thus use the information on the access network, and in particular the devices to be requested during the connection, to connect to the non-terrestrial access network and / or to the terrestrial network to transmit the data of an application, this information on the application being present in the connectivity profile associated with the terminal used to determine the connection policy.

[0076] A connection to a non-terrestrial network can nevertheless have an impact on the quality of experience of the terminal user and more directly on the application. Indeed, the latency of a non-terrestrial network can be higher than for a terrestrial network in particular and an application for example of the real-time type is particularly sensitive to higher latency. This is particularly the case if the constellation of the non-terrestrial network is of the geostationary type. The data transmission delay between the terminal and the access satellite can be estimated at around ten seconds, and such a delay could encourage a user to quit an application used, thinking of a malfunction.When the terminal connects to a non-terrestrial geostationary orbit network, the terminal, possibly via the application, warns the user that access may take an additional time and thus prevents the user from closing the application or even disconnecting from the geostationary access network, this warning being subsequent to the reception, during an optional step 105, by the terminal of a warning message relating to a delay in routing data from an active application.

[0077] In the case of using MPTCP or MPQUIC proxies, it may also be advantageous for the terminal to moderate its connection to the non-terrestrial network to accelerate the rapid convergence of transport layer congestion control in particular. Thus the proxy module, such as the terminal's MPTCP proxy, adapts the routing of data from an active application according to the connection policy received, which indicates to it a possibility of multiple connections, including a connection to a non-terrestrial access network.

[0078] According to one example, when the terminal connects to a non-terrestrial access network, the latter can advantageously implement congestion control of the connection established with the non-terrestrial access network, based on flow rate information associated with the non-terrestrial access network, received in the connection policy.

[0079] Reference is now made to which presents a representation of a DISP device for transmitting a connection policy according to an example, according to an aspect of the invention.

[0080] This device Disp is suitable for implementing the different embodiments of the method for transmitting a connection policy relating to the attachment of a terminal, said policy comprising a connection characteristic of the terminal associated with at least one non-terrestrial access network.

[0081] Such a Disp device is for example implemented in PCF type equipment, or ACS type equipment, or in any control equipment of a terrestrial or non-terrestrial access network.

[0082] The Disp device comprises a processing unit 230, equipped for example with a microprocessor μP, and controlled by a computer program 210, stored in a memory 220 and implementing the method of transmitting a connection policy relating to the attachment of a terminal according to the invention. The Disp device also comprises at least one communication interface (for example an Ethernet communication interface) and / or at least one human-machine interface, allowing it to receive and transmit data from and to other equipment present in a communication network to which it is connected and / or human operators.

[0083] Upon initialization, the code instructions of the computer program 210 are for example loaded into a RAM memory, before being executed by the processor of the processing unit 230. Such a processing unit 230 and such a memory 220 are capable and configured to obtain, via a module 201, a parameter associated with a set of access equipment of the at least one non-terrestrial access network, and to obtain a connectivity profile associated with the terminal, said profile being determined from a context associated with said terminal. These different means of obtaining are a single means of obtaining or distinct means and are for example communication interfaces of the Ethernet, Wi-Fi or xG type or any interface implemented in a Res communication network, controlled by the processing unit 230.The processing unit 230 and the memory 220 are further capable and configured to transmit to the terminal the connection policy, said policy being determined from the parameter and the connectivity profile obtained previously, the connection policy being intended to be used by the terminal to connect to the at least one non-terrestrial access network.

[0084] Reference is now made to the which presents a terminal (UE) comprising a device 300 for connecting a terminal to at least one non-terrestrial access network, according to one aspect of the invention. This device 300 is adapted to implement the different embodiments of the method for connecting a terminal to at least one non-terrestrial access network according to the different embodiments described above.

[0085] According to this example, the device 300 is implemented in a terminal (UE) represented by a smartphone. The terminal UE can also be an access device of a local network, also called Box, or an IoT device. The terminal (UE) can also be any device adapted to connect to a non-terrestrial network.

[0086] The device 300 comprises a processing unit 330, equipped for example with a microprocessor μP, and controlled by a computer program 310, stored in a memory 220 and implementing the connection method according to the invention. The device 300 also comprises at least one communication interface (for example an Ethernet communication interface) and / or at least one human-machine interface, allowing it to receive and transmit data from and to other equipment present in a communication network to which it is connected and / or human operators.

[0087] Upon initialization, the code instructions of the computer program 310 are for example loaded into a RAM memory, before being executed by the processor of the processing unit 330. Such a processing unit 330 and such a memory 20 are capable and configured to receive from a control device a connection policy, determined as a function of a parameter associated with a set of access equipment of the at least one non-terrestrial access network and a connectivity profile of the terminal, said profile being determined from a context associated with said terminal, and connect the terminal to the at least one non-terrestrial access network in accordance with the received connection policy.

Claims

Method for transmitting a connection policy relating to the attachment of a terminal (UE, Pass), said policy comprising a connection characteristic of the terminal (UE, Pass) associated with at least one non-terrestrial access network (Sat1, Sat2, Sat3), said method implemented in a control device (Disp) and comprising: - obtaining (100) by the control device a parameter P1 associated with a set of access equipment (Sat1a, Sat1b, Sat2, Sat3a, Sat3b) of the at least one non-terrestrial access network (Sat1, Sat2, Sat3), - obtaining (101) a connectivity profile P3 associated with the terminal (UE, Pass), said profile being determined from a context associated with said terminal (UE, Pass), - transmitting (103) to the terminal the connection policy P4, said policy being determined (102) from the parameter and the connectivity profile obtained previously, the connection policy being intended to be used by the terminal (EU,Pass) to connect to at least one non-terrestrial access network (Sat1, Sat2, Sat3)., Transmission method, according to claim 1, in which the connection policy comprises the at least one non-terrestrial access network (Sat1, Sat2, Sat3) with which a first priority information is associated, said first priority information being used by the terminal (UE, Pass) for the selection of one or more access networks to which the terminal transmits a connection request from among the at least one non-terrestrial access network. Transmission method, according to one of the preceding claims, in which the connection policy further comprises a connection characteristic of the terminal associated with at least one terrestrial access network (Wi-Fi, xG), and the method further comprises obtaining an attachment parameter to the at least one terrestrial network, said connectivity parameter to the at least one terrestrial network being further used to determine said connection policy. Transmission method, according to claim 3, wherein the connection policy further comprises the at least one terrestrial access network with which a second priority information is associated, said first and second priority information being used by the terminal for the selection of one or more access networks to which the terminal transmits a connection request from among the at least one non-terrestrial access network and the at least one terrestrial access network. Transmission method, according to one of the preceding claims, in which the parameter associated with the set of access equipment of the non-terrestrial network comprises a parameter characterizing the orbit or the altitude of the non-terrestrial network, the parameter being included in the following group: A parameter associated with a low orbit, A parameter associated with a medium orbit, A parameter associated with a geostationary Earth orbit, A parameter associated with a high altitude platform orbit. Transmission method according to one of the preceding claims, in which the transmission of the connection policy is transmitted via control equipment of a terrestrial or non-terrestrial access network. Transmission method according to one of the preceding claims, in which the parameter associated with the set of access equipment comprises one or more parameters from the following group: - a transmission quality of the at least one non-terrestrial access network, - an availability of the non-terrestrial access network, - an estimation of the quality of service of the data transmission associated with the at least one non-terrestrial access network, - information on the load of the at least one non-terrestrial access network. Transmission method, according to one of the preceding claims, in which the connectivity profile associated with the terminal comprises one or more data from the following group:- an indication that the terminal is located inside a building,- a use of the terminal,- at least one active application on the terminal,- an access technology of the terminal. Transmission method according to one of the preceding claims, in which the connection characteristic of the terminal associated with at least one non-terrestrial access network comprises one or more data from the following group: - a validity period of the transmitted policy, - a geographical indication of the transmitted policy, - quality of service data associated with the at least one non-terrestrial access network, - data on the entity responsible for managing the at least one non-terrestrial access network, - data associated with the authentication required for a connection to the at least one non-terrestrial access network, - data associated with the type of terminal. Method for connecting a terminal to at least one non-terrestrial access network, said method being implemented in the terminal prior to an attachment of the terminal to the at least one non-terrestrial access network, said method comprising:- a reception (103) from a device (Disp) for controlling a connection policy P4, determined as a function of a parameter associated with the constellation of the at least one non-terrestrial access network (Sat1, Sat2, Sat3) and a connectivity profile of the terminal (UE, Pass), said profile being determined from a context associated with the terminal,- a connection (104) of the terminal to the at least one non-terrestrial access network in accordance with the received connection policy. Connection method, according to claim 10, wherein the connection policy further comprises a connection characteristic of the terminal associated with at least one terrestrial access network, the connection method being implemented in the terminal prior to an attachment of the terminal to the at least one non-terrestrial access network or to the at least one terrestrial network. Connection method, according to claim 10 or claim 11, further comprising receiving (105) a warning message relating to a delay in routing data of an active application, in the case where the terminal attaches to a non-terrestrial access network characterized by a transit time of a message between the terminal and access equipment of the non-terrestrial network greater than a threshold value. Connection method, according to one of claims 10 to 12, in which the terminal simultaneously attaches to at least one non-terrestrial access network and at least one terrestrial access network via a proxy module, the proxy module adapting the routing of data from an active application according to the connection policy received. Connection method, according to one of claims 10 to 13, in which the terminal implements congestion control of the connection established based on flow rate information associated with the at least one non-terrestrial access network received in the connection policy. Device (Disp) for transmitting a connection policy relating to the attachment of a terminal, said policy comprising a connection characteristic of the terminal (UE, Pass) associated with at least one non-terrestrial access network (Sat1, Sat2, Sat3), said device implemented in a control device further comprising a processor and a memory coupled to the processor with instructions intended to be executed by the processor to:- obtain (100) by the control device a parameter associated with a set of access equipment of the at least one non-terrestrial access network,- obtain (101) a connectivity profile associated with the terminal, said profile being determined from a context associated with said terminal,- transmit (103) to the terminal the connection policy, said policy being determined from the parameter and the connectivity profile obtained previously,the connection policy being intended to be used by the terminal to connect to the at least one non-terrestrial access network., Device (300) for connecting a terminal (UE, Pass) to at least one non-terrestrial access network (Sat1, Sat2, Sat3), said device (300) being implemented in the terminal and further comprising a processor and a memory coupled to the processor with instructions intended to be executed by the processor for, prior to an attachment of the terminal to the at least one non-terrestrial access network: - receiving (103) from a control device a connection policy, determined as a function of a parameter associated with a set of access equipment of the at least one non-terrestrial access network and a connectivity profile of the terminal, said profile being determined from a context associated with the terminal, - connecting (104) the terminal to the at least one non-terrestrial access network in accordance with the received connection policy. System for transmitting a connection policy relating to the attachment of a terminal, said policy comprising a connection characteristic of the terminal associated with at least one non-terrestrial access network, said system comprising:- at least one transmission device (Disp) according to claim 15,- at least one connection device (300) according to claim 16. Computer program product downloadable from a communications network and / or stored on a computer-readable medium and / or executable by a microprocessor, characterized in that it comprises program code instructions for executing a method according to any one of claims 1 to 9 or according to any one of claims 10 to 14, when executed by a computer.

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