Method implemented by a network device for monitoring the use of resources to communicate with at least one terminal, and associated network device, terminal, system and computer program

Abstract

The present invention relates to a method implemented by a network device (SAT_X, SAT_Y) for monitoring the use of resources to communicate with at least one terminal (UE), the method comprising: - sending (SX120, SX130, SY140) data (DATA_X, COOP_DATA) to said at least one terminal (UE); and - sending (SX120, SX130, SY140), to a monitoring entity (GW) and / or said at least one terminal (UE), one or more proofs of use (TUCP, TUDP) indicating resources used by said network device (SAT_X, SAT_Y) to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE).

Description

Description Title of the invention: Method implemented by a network device for tracking resource usage for communicating with at least one terminal, network device, terminal, system, and associated computer program Technical field

[0001] The present invention relates to the general field of telecommunications. In particular, the present invention relates to a method implemented by a network device for tracking resource usage for communicating with at least one terminal, a method implemented by a terminal, a network device, a terminal, a tracking entity, a system, a computer program and an associated information medium. The present invention finds a particularly advantageous, although in no way limiting, application for the implementation of satellite mobile telephone networks. State of the prior art

[0002] The invention is placed in particular in the context of the delegation of resources between communication systems, a mechanism in which a first system makes resources (resources, radio, IT, network, etc.), such as for example a frequency spectrum, available to one or more other systems according to determined methods which define for example the resources concerned, the duration or period of provision, parameters of use of these resources, and pricing or billing conditions for the use of these resources.

[0003] Existing communication systems do not allow for reliable control of resource delegation between different communication systems. For example, when interconnecting mobile or cellular networks, network operators cannot ensure that delegation terms are respected. Indeed, when an operator uses a third-party radio access network (RAN), the operator cannot dynamically control spectrum usage rights and conditions. Existing solutions rely on static proof of spectrum ownership, e.g., an operator provides its spectrum licenses when it uses a third-party radio access network. However, it appears necessary to be able to dynamically prove spectrum ownership and also to control the use of this spectrum for communications.

[0004] For example, there are currently various state-of-the-art communication systems using satellites, allowing users to access a network (e.g. the Iridium network, ViaSat, Starlink) regardless of their location. For example, it is known to use satellites in medium or low orbits to deploy satellite communication systems. However, it should be noted that a communication system based on satellites in medium or low orbits requires a constellation of many satellites as well as many ground stations. However, to provide users with continuous geographical coverage, it may be necessary for several satellites to cooperate with each other to communicate data to terminals. It therefore appears essential, to implement such cooperation and delegate resources between satellites, to be able to dynamically prove ownership of a spectrum and to control the use of this spectrum for communications.

[0005] Furthermore, for existing communication systems (e.g. terrestrial or satellite), communications billing is typically carried out statically through flat-rate contracts. Generally, communications for a terminal are billed based on a maximum data volume allowed over a period of time (e.g. 10 GB / month). Existing billing solutions have a number of drawbacks that need to be addressed. In particular, such static billing solutions are not suitable for emerging use cases, such as connected object networks, communicating vehicles, etc., which require more flexible billing solutions and not solely based on volume.

[0006] There is therefore a need for a solution to improve the traceability and control of communications implemented by a communication system, particularly in a context of resource delegation. Statement of the invention

[0007] The present invention aims to remedy all or part of the drawbacks of the prior art, in particular those set out above.

[0008] To this end, according to one aspect of the invention, a method is proposed implemented by a network device for tracking resource usage for communicating with at least one terminal, the method comprising:

[0009] a sending, to said at least one terminal, of data; and

[0010] a sending, to a tracking entity and / or said at least one terminal, of one or more proofs of use indicating resources used by said network device to communicate said data to said at least one terminal.

[0011] The proposed method makes it possible to achieve traceability of the resources used by a communication system to communicate data to a terminal. Indeed, the proposed method allows a network device (e.g. a satellite, an aircraft, a terrestrial radio access point, etc.) to dynamically inform a monitoring entity of the resources used. Compared to existing solutions, the proposed method has the particular advantage of being dynamic.

[0012] By "network device", reference is made here to a communication device of an access network, for example a radio access network, making it possible to communicate data to terminals. According to one embodiment, said network devices are included in aircraft or satellites. For the purposes of the invention, the terms "aircraft" and "satellite" refer respectively to: any device capable of rising into the air such as a drone, an airplane, a high altitude platform (or HAP for "High Altitude Platform"); and to any device placed in orbit around a planet (Earth, Mars; ...) such as artificial satellites (e.g. telecommunications satellite). However, within the scope of the invention, other embodiments may be envisaged in which said network devices are terrestrial and are mobile or not.

[0013] In the context of the invention, it should be noted that the expressions "from" and "to" in no way limit the nature of the interface between the sender and the recipient of a message, the link between these two entities being able to include intermediate equipment relaying the message. Also, the sending of data to the terminal and the sending of proofs of use to the terminal can be carried out concomitantly or independently.

[0014] By "resource" is meant here any resource of a communication equipment and can thus designate communication resources (e.g. a frequency channel, a time slot, a pair consisting of a frequency and a time slot, etc.), energy resources, computing resources, etc. In particular, the expression "resource used to communicate" can designate a resource used for all operations necessary for communication such as: transmission, reception, data processing, as well as synchronization and control. Also, the proofs of use within the meaning of the invention indicate the communication resources actually used by the network devices to communicate data to the terminals.For example, a proof of use may indicate a number of frequency channels, a time interval, a number of time-frequency blocks, a transmission power, and / or an energy consumed to communicate data to the terminals. In particular, a proof of use is, according to one embodiment, a token-type message signed by the issuer (i.e. the author) of the proof, user of the resource.

[0015] The term "tracking entity" means a device implementing resource tracking by a satellite communication system to communicate with terminals.

[0016] According to one embodiment, the evidence of resource usage is sent to: a first tracking entity included in a network device management entity, for example operated by a mobile operator; and to a second tracking entity included in a ground station, for example operated by a network access device operator. In particular, the network device can send said evidence of resource usage to the second tracking entity; and the terminal can send said evidence of resource usage, received from at least one network device, to the first tracking entity. "Ground station" is understood to mean network equipment located on Earth, making it possible to connect one or more network devices to a terrestrial communication network.

[0017] According to one embodiment, for each sending of data to a terminal, the terminal sends, to a monitoring entity, said one or more proofs of use indicating resources used during this communication. This embodiment makes it possible to implement precise monitoring of resources with fine granularity (i.e. with a high level of detail). In addition, this embodiment makes it possible to obtain proof of the completion of a communication, since the monitoring entity receives the proofs of use from the terminal for which the communication was made.

[0018] By way of example, the proposed method can in particular be advantageously used to deploy billing solutions based on the resources used. Such billing solutions appear to be essential to meet the needs of new use cases for communication systems, such as networks of connected objects, communicating vehicles, etc. In this example, the terminal receives both the data and the proof of use indicating the resources used. The terminal can then transmit this information to a tracking entity of a mobile network operator as proof of delivery of a communication; and the tracking entity triggers the billing of this communication on the basis of this information.

[0019] According to one embodiment, said network device sends, to a tracking entity and / or said at least one terminal, one or more proofs of use indicating resources used by at least one other network device to communicate said data to said at least one terminal.

[0020] It should be noted that the sending of proof of use relating to the different network devices can be carried out simultaneously or independently.

[0021] This embodiment has the particular advantage of tracking the resources used by multiple network devices to communicate data to terminals. Hereinafter, the term cooperation is used to denote the fact that multiple network devices are used collaboratively to communicate with terminals.

[0022] In this embodiment, said proofs of use signal the involvement of a plurality of network devices to communicate data to a terminal. Thus, this embodiment makes it possible to trace the resources respectively used during cooperation between network devices.

[0023] For illustrative purposes, an example is considered here in which a first network device requests a second network device to relay to a terminal part of the data to be transmitted to the latter. In this example, the proofs of use indicate the resources respectively used by each of the two network devices. In this way, the monitoring entity is able to trace the cooperation between the network devices, and in particular to track the resources used by the second network device to relay data to the terminal.

[0024] According to one embodiment, said one or more proofs of use are signed by a private key associated with a certified entity.

[0025] The term "private key" and "public key" refers to a pair of keys associated with an entity and used to implement an asymmetric encryption scheme, the private key being intended to be confidential and the public key being intended to be publicly disseminated. In a particular embodiment of the invention, an encryption scheme is used in particular to generate session keys authenticating messages such as proofs of use and usage authorizations.

[0026] By "signature" is meant a digital signature, i.e. data added to a message, allowing the recipient of the message to verify the author of this message as well as the integrity of the latter. The signature of a message is, according to one embodiment, obtained by encrypting a hash of the message. Thus, upon receipt of the message, the recipient simply needs to decrypt the signature of the message, then compare the decrypted signature to a hash of the received message to ensure the authenticity and integrity of the message.

[0027] Furthermore, in the context of the invention, a “certified entity” means an entity authorized to operate resources and having, as such, a certificate. By way of illustration, a certified entity may be a mobile operator that owns a certain frequency spectrum and authorizes network devices to use this spectrum to communicate with terminals. In particular, the proofs of resource usage sent by the network devices may be signed with a private key of the operator of the network devices, or may be signed using an algorithm based on an identifier of the operator, for example deriving an encryption key from this identifier.

[0028] An advantage of this embodiment is that it guarantees the reliability of resource usage tracking. Indeed, this embodiment ensures the authenticity and integrity of the proofs of use transmitted relating to the resources used. Any recipient of this proof usage is able to verify the authenticity and non-repudiation of information using the public key of the certified entity.

[0029] For example, an operator may have a private-public key pair allowing it to prove that it owns a frequency spectrum. In particular, a frequency regulatory authority (e.g. ARCEP, the regulatory authority for electronic communications, posts and press distribution, or the GSMA) signs a public key certificate (e.g. an X.509 certificate) for each spectrum (e.g. a certificate for each carrier of a radio access network) owned by an operator. This operator certificate allows it to distribute a certificate per access network or RAN (acronym for "Radio Access Network") including its public key with the signature of a regulatory authority (i.e. a trusted authority). As a result, the recipients (user network devices) are thus able to authenticate the spectrum ownership information signed by this operator.

[0030] According to one embodiment, said one or more proofs of use indicate frequency resources used to communicate data to said at least one terminal. This embodiment makes it possible to reliably and accurately track the frequency resources used by one or more network devices during communication with terminals.

[0031] In combination with one or more of the preceding embodiments, this embodiment makes it possible in particular to track the frequency resources delegated during cooperation between network devices. This embodiment is particularly advantageous in that it makes it possible, when a network device delegates (i.e. makes available) part of its resources to cooperate with at least one other satellite, to prove the delegation of resources.

[0032] According to one embodiment, said one or more proofs of use indicate time-frequency resources used to communicate application data to said at least one terminal and associated control data.

[0033] In this embodiment, a distinction is made between the use of resources to communicate application data (or payload data) and the use of resources to communicate control data. By "application data" is meant here data of a communication service (i.e. a function), for example data of a telephone communication, data of a video stream, etc. And, by "control data" is meant here data necessary for the implementation of a communication service (i.e. a function), such as signaling data, synchronization data, etc.

[0034] This embodiment allows for precise tracking of the resources used, in particular by differentiating the tracking of resources used to communicate application data and to communicate control data. It should be noted that the communications of these two Data types are typically implemented using separate resources, such that this embodiment allows for the use of these different resources to be accounted for.

[0035] This embodiment is particularly advantageous because it makes it possible to track both the resources used for the communication of useful data and also the resources used for the implementation of this communication, e.g. signaling, synchronization, etc. For example, in the context of cooperation between network devices, a certain number of exchanges is necessary between the different network devices to implement this cooperation. This embodiment makes it possible, in this case, to count these exchanges in the monitoring of the resources used. Furthermore, this embodiment makes it possible to gradually initiate exchanges between network devices over time without intervention from the network device management entities, even when the network devices are operated by different operators. This embodiment thus allows the network devices to receive, verify and count the proofs of use over time.

[0036] According to one embodiment, said one or more proofs of use indicate a quantity of energy resources consumed to communicate said data to said at least one terminal. This embodiment makes it possible to count, in the monitoring of the resources used, the energy resources consumed by one or more network devices to communicate data to a terminal.

[0037] According to one embodiment, the network device sends all or part of said data to said at least one terminal via at least one other network device.

[0038] This embodiment makes it possible to improve the performance of a satellite communication system (e.g. a satellite access network), particularly in terms of coverage, throughput and reliability.

[0039] Indeed, this embodiment makes it possible to implement cooperation between network devices in order to communicate with terminals, i.e. several network devices are used to communicate data to the terminals. Such cooperation allows a network device to benefit, thanks to the cooperation, from the resources of at least one other network device to communicate with terminals. Such cooperation allows, for example, the network device to artificially expand its coverage area by benefiting from the coverage area of ​​at least one other network device.

[0040] This embodiment makes it possible to increase the power of the signal received by a terminal. For example, a first network device can increase the power of the signal received by a terminal by cooperating with a second relay network device (i.e. repeater) closer to the terminal.

[0041] According to one embodiment, said sending of all or part of said data to said at least one terminal via said at least one other network device is triggered following receipt of a usage request message received from said at least one terminal.

[0042] According to one embodiment, said message received from said at least one terminal comprises information relating to a power level received by said at least one terminal. No limitation is attached to the nature of the information relating to a received power level. It may in particular take the form of a request to increase the received power, a received power level, a signal-to-interference-plus-noise ratio (or SINR), an indication that the received power level is below a given threshold.

[0043] According to one embodiment, the sending of said data by said network device to said at least one terminal comprises:

[0044] sending, to at least one terminal, a first portion of said data; and

[0045] sending, to at least one other network device, a second portion of said data to be transmitted to said at least one terminal.

[0046] It should be noted that, in this embodiment, the expressions “first portion of said data” and “second portion of said data” may designate all or part of said data to be transmitted to said at least one terminal. Furthermore, the first and second portions of data may be identical in whole or in part, or different.

[0047] In this embodiment, a plurality of point-to-point links are used to transmit data to the terminals.

[0048] Thus, this embodiment makes it possible in particular to exploit coordinated multi-point techniques, more commonly referred to as CoMP (acronym for the English expression “Coordinated Multi-Point”). By thus exploiting the spatial domain of the communication channel, this embodiment makes it possible to benefit from the respective advantages of spatial diversity or spatial multiplexing schemes, which are respectively: to increase reliability and range; and to increase the throughput of communications. Consequently, this embodiment makes it possible to improve communication performance in terms of coverage, throughput and reliability.

[0049] Furthermore, this embodiment makes it possible to implement frequency and / or time multiplexing techniques and thus makes it possible to increase the communication rate. For example, the two network devices can transmit two independent data streams to the terminals by exploiting all or part of two distinct frequency bands so as to increase the transmission rate.

[0050] According to one embodiment, said method comprises:

[0051] sending, to said at least one network device, a request for transmission of data to said at least one terminal, the transmission request comprising one or more proofs of use indicating resources used by said network device; and

[0052] a receipt, from said at least one other network device, of a response comprising one or more proofs of usage indicating resources used by said at least one other network device.

[0053] This embodiment falls within the context of cooperation between network devices described above. In this embodiment, at least two network devices cooperate (i.e. are used) to communicate data to the terminals. In particular, when two network devices cooperate, this embodiment allows each of the two network devices to have proof of use indicating the resources used by the two network devices. Thus, each of the network devices is able to trace the resources used by several network devices during a cooperation and to prove this cooperation.

[0054] For illustration purposes, a cooperation between two satellites (network devices within the meaning of the invention) operated by separate mobile network operators is considered. One of the operators delegates part of its resources (e.g. a frequency spectrum) to the other operator to communicate data to terminals. Thanks to this embodiment, each of the operators is able to reliably and accurately track the resources used by the two network devices, and in particular the delegated resources.

[0055] According to one embodiment, the method comprises:

[0056] a receipt, from a certified entity, of a public key associated with the certified entity;

[0057] a receipt, from the certified entity, of an authorization to use at least one resource comprising a signature determined from a private key associated with the certified entity; and

[0058] an authentication of said authorization from the signature and public key received.

[0059] As described above, "authentication" means verifying the identity of the author of a message or data and furthermore the integrity of this message or data, and in particular, at least in this embodiment, the certificate associated with the authorization of use.

[0060] This embodiment allows for the reliable and secure control of resource exploitation. Indeed, in this embodiment, a certified entity authorizes a device network to use certain resources to communicate with terminals. This could be, for example, the owner of a satellite spectrum or 4G or 5G.

[0061] For example, the authorization of use (or exploitation) may indicate to a network device that it can use a certain frequency spectrum to communicate with terminals. Such an authorization of use may be issued by an operator who owns this spectrum, and who has a public key certificate as described above. In this way, if a network device receives an authorization to use this spectrum, it is able to authenticate this authorization and confirm that the owner operator is indeed the author of this information and that it delegates its use to the network device for the duration indicated in the authorization.This type of delegation is for example carried out using protocols such as the STAR protocol as described in the RFC 8555 document published by the IETF dated March 2019, or the Subcert protocol described in the document published by the IETF and entitled "Delegated Credentials for (D)TLS - draft-ietf-tls-subcerts-15", June 15, 2022.

[0062] According to one embodiment, which finds a particular but non-limiting advantage in the context of a cooperation mentioned above between a first and at least one second network device - for example between two satellites, the method comprises:

[0063] a reception, by a first network device from a management entity of this cooperation, of information relating to resources of at least one second network device which can be used to transmit data to said at least one terminal;

[0064] if a so-called cooperation criterion is verified, triggering cooperation with said at least one other network device based on said information to transmit data to said at least one terminal, said cooperation comprising sending, to said at least one other network device, data to be transmitted to said at least one terminal.

[0065] By "cooperation criterion" is meant here a criterion that conditions the implementation of cooperation by the first network device with the second network device. Hereinafter, the resources of a network device that can be used for cooperation are also called shareable or usable resources.

[0066] This embodiment makes it possible to improve the performance of a communication system, particularly in terms of coverage, throughput and reliability. Indeed, this embodiment makes it possible to implement cooperation between network devices in order to communicate with terminals.

[0067] This embodiment allows a network device to implement cooperation autonomously and dynamically with other network devices, which makes it possible to respond to rapid variations in the flow rates of the data to be communicated to the terminals. In addition, this embodiment requires only minimal and decorrelated signaling (of said variations fast speeds) between the cooperation entity and the network devices to implement cooperation.

[0068] The autonomy, i.e. the initiative capacity, of the network devices with regard to the implementation of cooperation is enabled by sending them information relating to the resources that can be used for cooperation. Indeed, during the validity period of the received information, the network devices have the information required to initiate cooperation if necessary. This embodiment thus makes it possible to implement a low-complexity communication system for carrying out cooperation between network devices, for example between satellites.

[0069] The autonomy of network devices with respect to the implementation of cooperations can also be enabled by sending resource delegation authorizations to a network device. Following the reception of these authorizations, a network device is for example informed that another network device is authorized to cooperate and can thus initiate cooperation if necessary with this other network device. This embodiment can be described as an “opportunistic” cooperation mode.

[0070] According to another aspect of the invention, there is provided a method implemented by a terminal for tracking resource usage for communicating with at least one network device, the method comprising receiving, from said at least one network device, data; and

[0071] a reception, from said at least one network device, of one or more proofs of use indicating resources used by said at least one network device to communicate said data to the terminal.

[0072] According to one embodiment, the terminal sends said proof of use to a monitoring entity.

[0073] According to another aspect of the invention, there is provided a network device for communicating with at least one terminal comprising:

[0074] a sending module configured to send data to said at least one terminal; and

[0075] a sending module configured to send, to a tracking entity and / or said at least one terminal, one or more proofs of use indicating resources used by said network device to communicate said data to said at least one terminal.

[0076] According to another aspect of the invention, there is provided a terminal comprising:

[0077] a receiving module configured to receive, from at least one network device, data and one or more proofs of use indicating resources used by said at least one network device to communicate said data to the terminal.

[0078] According to one embodiment, the terminal further comprises a sending module configured to send, to a tracking entity, said proof of use.

[0079] According to another aspect of the invention, there is provided a tracking entity comprising:

[0080] a receiving module configured to receive, from at least one network device and / or at least one terminal, one or more proofs of use indicating resources used by said at least one network device to communicate data to said at least one terminal.

[0081] According to one aspect of the invention, there is provided a system comprising:

[0082] at least one network device according to the invention; and

[0083] at least one terminal in accordance with the invention.

[0084] The features and advantages of the method implemented by a network device according to the present invention described above also apply to the proposed network device, terminal implemented method, terminal, tracking entity and system.

[0085] According to one embodiment, the system further comprises a tracking entity according to the invention.

[0086] According to one aspect of the invention, there is provided a computer program comprising instructions for implementing the steps of a method according to the invention, when the computer program is executed by at least one processor or computer.

[0087] The computer program may consist of one or more subparts stored in a single memory or in separate memories. The program may use any programming language, and may be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form. In addition, the computer program may be executed on at least one processor or computer on board a satellite or aircraft or any other network device.

[0088] According to one aspect of the invention, there is provided a computer-readable information medium comprising a computer program according to the invention.

[0089] The information carrier may be any entity or device capable of storing the program. For example, the carrier may include a storage medium, such as a non-volatile memory or ROM, for example a CD-ROM or a microelectronic circuit ROM, or a magnetic recording medium, for example a floppy disk or a hard disk. On the other hand, the storage medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by a telecommunications network or by a computer network or by other means. The program according to the invention may in particular be downloaded onto a computer network. Alternatively, the information medium may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question. Brief description of the drawings

[0090] Other features and advantages of the present invention will become apparent from the description provided below of embodiments of the invention. These embodiments are given for illustrative purposes and are not intended to be limiting. The description provided below is illustrated by the attached drawings: [Fig. 1] Figure 1 schematically represents a communication system making it possible to illustrate cooperations implemented between network devices in a context of application of the invention; [Fig. 2] Figure 2 represents, in the form of a flowchart, steps of a communication method making it possible to illustrate cooperation implemented between network devices in a context of application of the invention; [Fig. 3] Figure 3 represents, in the form of a flowchart, steps of a communication method according to one embodiment of the invention; [Fig. 4] Figure 4 represents, in the form of a flowchart, steps of a communication method according to one embodiment of the invention; [Fig. 5] Figure 5 schematically represents an example of software and hardware architecture of a communication system according to an embodiment of the invention; [Fig. 6] Figure 6 schematically represents an example of functional architecture of a communication system according to an embodiment of the invention. Description of the embodiments

[0091] The present invention relates to a method implemented by a network device for tracking resource usage for communicating with at least one terminal, a method implemented by a terminal, a network device, a terminal, a tracking entity, a system, a computer program and an associated storage medium.

[0092] The present invention applies in particular to satellite communication systems, as described below with reference to Figures 1 to 6. However, the invention also applies to any type of communication system, in particular terrestrial or aircraft communication systems.

[0093] Figure 1 schematically represents a communication system making it possible to illustrate cooperation implemented between network devices in a context of application of the invention.

[0094] In this embodiment, the present invention is part of a context where several satellites (network devices within the meaning of the invention) cooperate to communicate data to terminals. Figure 1 illustrates several types of cooperation between network devices.

[0095] As illustrated in Figure 1, the satellite communication system comprises, according to one embodiment: a ground station GW; a first satellite SAT_X; a second satellite SAT_Y and at least one terminal UE. The communication system transmits data from a communication network NET to said at least one terminal UE, said at least one terminal UE being included in a cell CELL. To do this, the communication system implements inter-satellite cooperation: several satellites SAT_X and SAT_Y of the communication system are thus used to communicate data to said at least one terminal UE.

[0096] The term "cell" is used here to designate a terrestrial geographic region covered by a beam of one of the antennas of the communication network device or by a beam of one of the antennas of a terrestrial mast, the terrestrial mast being able for example to be operated by an infrastructure management entity of a radio access network (more commonly referred to as "TowerCo" abbreviation of the expression "TowerCompany" in English). The covered geographic region includes the volume constituted by the cone of the beam.

[0097] According to a first embodiment, the inter-satellite cooperation is of the relay type, the second satellite SAT_Y being operated as a relay between the first satellite SAT_X and said at least one UE terminal. This first embodiment makes it possible in particular to enlarge the coverage area of ​​the communication system, the first satellite SAT_X “artificially” benefiting from the coverage area of ​​the second satellite SAT_Y to communicate with UE terminals. Furthermore, this embodiment makes it possible to increase the power of the signal received by said at least one UE terminal, typically by selecting a relay satellite SAT_Y closer to the cell CELL in which the UE terminal is located, which thus makes it possible to improve the reliability and / or the throughput of the communications.

[0098] In this first embodiment, the ground station GW is configured to communicate with the communication network NET. To implement a relay-type cooperation, the ground station GW sends, to the first satellite SAT_X, information COOP_DIM relating to resources of the second satellite SAT_Y that can be used to transmit data in the cell CELL, and therefore can be used in the context of inter-satellite cooperation. According to an exemplary implementation, the COOP_DIM information corresponds to a number of available channels of the second satellite SAT_Y. The ground station GW further sends, to the first satellite SAT_X, DATA data to be communicated to said at least one UE terminal. This DATA data here comprises a first set of COOP_DATA data and a second set of DATA_X data, detailed below.

[0099] No limitation is attached to the origin of the COOP_DATA data to be transmitted. It may be envisaged within the framework of the invention that the data to be transmitted to the terminals are generated by the network devices. Thus, according to one embodiment, the COOP_DATA data to be transmitted to said at least one UE terminal are emitted or transmitted by the SAT_X satellite.

[0100] The first satellite SAT_X thus receives, from the ground station GW, the COOP_DIM information and the DATA data. On the basis of the COOP_DIM information, the first satellite SAT_X sends, to the second satellite SAT_Y, a COOP_QUERY request for data transmission to said at least one UE terminal and the COOP_DATA data to be transmitted to said at least one UE terminal. Hereinafter, the COOP_QUERY request for data transmission to said at least one UE terminal is also referred to as a cooperation request.

[0101] The second satellite SAT_Y receives, from the first satellite SAT_X, the cooperation request COOP_QUERY and the data COOP_DATA to be transmitted to said at least one UE terminal. Following this reception, the second satellite SAT_Y sends, to said at least one UE terminal, the data COOP_DATA.

[0102] Said at least one UE terminal receives, from the second satellite SAT_Y, the COOP_DATA data.

[0103] The invention thus makes it possible, in this first embodiment, to implement inter-satellite cooperation initiated by the satellites themselves autonomously. As a result, the invention requires only a few exchanges between the ground station and the satellites to implement cooperation, which in particular makes it possible to deploy a satellite communication system with a limited number of ground stations. Furthermore, the invention makes it possible, thanks to the autonomy of the satellites, to implement inter-satellite cooperation opportunistically and dynamically, and makes it possible to respond to rapid variations in throughput.

[0104] By way of illustration, the present invention can be used to implement mobile telephone networks based on OFDMA (Orthogonal Frequency Division Multiple Access) type radio access technologies.

[0105] No limitation is attached to the nature of the NET communication network, which may be a mobile telephone network (2G, 3G, 4G, 5G, 6G, etc.), a computer network of the Internet, or any other network (proprietary, etc.) that may be considered. The communication interface between the NET network and the GW ground station may be wired or wireless, and may implement any protocol known to those skilled in the art.

[0106] No limitation is attached to the nature of the communication interfaces between: the ground station GW and the first satellite SAT_X; and between the first satellite SAT_X and the second satellite SAT_Y. In particular, according to one embodiment, one or more intermediate satellites are used to relay data from the ground station GW to the first satellite SAT_X and / or from the first satellite SAT_X to the second satellite SAT_Y.

[0107] According to the invention, the satellites of the SYS communication system can describe geostationary, medium or low Earth orbits. As a result, the coverage areas of the different satellites can be fixed or moving over time. Furthermore, it is important to note that the satellites of the communication system can be operated by the same satellite operator or by different satellite operators. In the latter case, the communication system allows cooperation between several mobile and / or satellite operators to be implemented.

[0108] UE terminals may be of the mobile telephone type, for example a Smartphone, or a tablet, or a computer or any other type of communicating device, in particular communicating objects (more commonly referred to as “loT” for “Internet of Things” in English).

[0109] According to a second embodiment, the inter-satellite cooperation implemented by the communication system is of the CoMP type (acronym for the English expression “Coordinated Multi-Point”). According to this second embodiment, the first satellite SAT_X and second satellite SAT_Y are used to transmit DATA_X and COOP_DATA data in a coordinated manner to said at least one UE terminal, using the same time-frequency resources. This second embodiment makes it possible to exploit the spatial domain of the communication channel to improve communication performance in terms of coverage, throughput and / or reliability. According to this embodiment, the satellites SAT_X and SAT_Y coordinate their transmissions so that, at said at least one UE terminal, the reception of the DATA_X data from the first satellite SAT_X is synchronized with the reception of the COOP_DATA data from the second satellite SAT_Y.

[0110] No limitation is attached to the nature of the DATA_X and COOP_DATA data respectively sent by the first satellite SAT_X and the second SAT_Y. Furthermore, the DATA_X and COOP_DATA data may be identical or different. It should be noted that, according to one embodiment, the COOP_DATA and DATA_X data are included in the DATA data. [YES] According to a third embodiment, the inter-satellite cooperation implemented by the communication system is of the carrier aggregation type. In this third mode, the first SAT_X and the second satellite SAT_Y are used to simultaneously send, to said at least one UE terminal, DATA_X and COOP_DATA data using different frequency resources. This third embodiment makes it possible to implement frequency multiplexing, and thus to improve the transmission rate.

[0112] According to a fourth embodiment, the inter-satellite cooperation consists of using the second satellite SAT_Y as a relay to carry out control transfer, called “long handover” (or long intercellular transfer), of said at least one terminal of the first satellite SAT_X to a third satellite. This fourth embodiment makes it possible to enlarge the coverage area of ​​the communication system and to ensure continuity of service for the terminals.In this fourth embodiment, the switching of control of the UE terminal to the third satellite can be carried out in the following manner: during a first time interval, the earth station GW sends, to the first satellite SAT_X, data to be transmitted to said at least one UE terminal, this data being transmitted to the UE terminal via the second satellite SAT_Y; then, during a second subsequent time interval, the earth station GW sends, to the third satellite, other data to be transmitted to the UE terminal. Thus, the earth station GW switches the data flow to the UE terminal from the first satellite SAT_X to the third satellite.

[0113] Figure 2 represents, in the form of a flowchart, steps making it possible to illustrate cooperations implemented between network devices in a context of application of the invention.

[0114] As mentioned previously, the present invention falls within a context where several network devices cooperate to communicate data to terminals and applies in particular to satellite communication systems. Figure 2 thus describes the exchanges between the elements of a communication system implementing cooperation between satellites according to the embodiments of the invention described previously with reference to Figure 1.

[0115] In the embodiment illustrated by FIG. 2, the communication system comprises a server SERVER; a network entity NE; a ground station GW; a first satellite SAT_X; a second satellite SAT_Y; and at least one terminal UE.

[0116] Figure 2 describes steps implemented by the different elements of the communication system according to one embodiment and illustrates data exchanges between these elements over time. The following reference signs make it possible, for each of the steps of the method, to identify the element implementing this step: the references beginning with SS are used for the steps implemented by the server SERVER; SN for the network entity NE; SG for the ground station GW; SX for the first satellite SAT_X; SY for the second satellite SAT_Y; SU for said at least one terminal UE.

[0117] According to this embodiment, the server SERVER is an application server transmitting DATA data to said at least one UE terminal. For example, the server SERVER may be a mobile telephony server, or a web server. However, within the scope of the invention, other embodiments may be envisaged in which the first satellite SAT_X generates the DATA data to be transmitted to said at least one UE terminal.

[0118] According to this embodiment, the network entity NE is operated by a mobile operator called MNO (acronym for the English expression “Mobile Network Operator”), while the ground station GW is operated by a satellite operator called SNO (acronym for the English expression “Satellite Network Operator”).

[0119] During a step SG10, the ground station GW receives, from the network entity NE, AUTH resource delegation authorizations (sent during a step SN10). The AUTH resource delegation authorizations specify the communication resources that can be exploited by the network devices (such as satellites) to cooperate. The AUTH authorizations are, for example, sent by one or more mobile operators MNO and specify the spectra and spots that can be exploited by the satellites to cooperate.

[0120] During a step SG20, the ground station GW sends cooperation authorizations COOP_AUTH (received during steps SX20 and SY20) to the satellites SAT_X and SAT_Y. For illustration, a cooperation authorization COOP_AUTH authorizes the second satellite SAT_Y to cooperate with the first satellite SAT_X and vice versa.

[0121] During a step SG30, the ground station GW receives, from the satellites SAT_X and SAT_Y, CAP_SAT information relating to the resources of the satellites SAT_X and SAT_Y (sent during steps SX30 and SY30). For example, for a satellite SAT_X, the CAP_SAT information may designate the available frequency channels estimated by the CAP_COOP module for transmitting data to said at least one UE terminal.

[0122] During a step SG40, the ground station GW receives, from the entity NE, REQ_FORE information relating to specifications of the communication system (sent during a step SN40). For example, the REQ_FORE information is transmitted by a mobile operator MNO and corresponds to forecasts of needs to implement a communication service, in terms of target throughput, probability of non-coverage, and the number of connections required over a period of time.

[0123] In particular, a CAP_COOP module of the GW ground station receives the CAP_SAT and REQ_FORE information for a group of satellites: SAT_X, and / or SAT_Y. The information COOP_DIM, described in more detail later, is determined by this CAP_COOP module. According to one embodiment, the CAP_COOP module is common to the SAT_X and SAT_Y satellites. According to other embodiments, there is one CAP_COOP module per group of satellites. The communication system may comprise one or more operational / functional support systems (or OSS / BSS acronym for the expression "Operational Support System / Business Support System" in English) per satellite operator SNO or mobile operator MNO. Thus, depending on the architecture of the communication system (one or more OSS / BSS per MNO or SNO), a group of satellites may comprise either the group of satellites seen by a ground station GW, or all the satellites of a constellation), e.g. a CAP_COOP module for each of the SAT_X and SAT_Y satellites.

[0124] During a step SG50, the ground station GW determines, using the CAP_COOP module, COOP_DIM information relating to the resources of the satellites that can be used for cooperation. According to one embodiment, the COOP_DIM information corresponds to the number of free channels of the satellites, these free channels being able to be used for cooperation.

[0125] According to one embodiment, the COOP_DIM information is determined by the CAP_COOP module of the ground station GW during a step SG50 from the CAP_SAT and REQ_FORE information. In particular, the COOP_DIM information for the SAT satellite can be determined from a transmission rate D and an outage probability P_OUT relating to the service of the SAT satellite, the rate D and the outage probability P_OUT being included in the REQ_FORE information. The COOP_DIM information can further be determined from a statistic of the communication channel between the satellite and a terminal.

[0126] During a step SG60, the ground station GW sends, to the satellites SAT_X and SAT_Y, the COOP_DIM information (received during steps SX60 and SY60). For example, the COOP_DIM information is sent to the satellite SAT_X and indicates to it that the satellite SAT_Y has a plurality of channels that can be used to transmit data in the cell CELL. It should be noted that when the satellites SAT_X and SAT_Y belong to different constellations then the COOP_DIM information relating to the first satellite SAT_X can be transmitted to the ground station in charge of the second satellite SAT_Y and vice versa.

[0127] During a step SX65, according to a particular embodiment, the first satellite SAT_X sends, to said at least one UE terminal, data DATA_T1 (received during a step SU65).

[0128] During a step SX70, according to a particular embodiment, the first satellite SAT_X receives, from said at least one UE terminal, a usage request message named BOOST (sent during a step SU70). The BOOST usage request includes a parameter which may in particular designate a request to increase the received signal power by N dB (decibels), a received signal power level, or indicate that the received signal power is below a threshold, etc. For example, the BOOST usage request is a signal-to-interference-plus-noise ratio, more commonly referred to as SINR (acronym for the English expression “Signal-to-Interference-plus-Noise Ratio”), at the UE terminal for a signal received from the first satellite SAT_X. As an illustration, this BOOST usage request is for example sent by a UE terminal (e.g. an aging connected object) whose reception is deteriorating. This BOOST usage request is signed by the terminal and thus represents a commitment by the UE terminal to “pay” the costs associated with the action implemented to process the UE terminal’s usage request.The reception of the usage request message sent by the UE terminal, for example in the form of a token signed by the UE terminal, by a monitoring entity (e.g. satellite and / or mobile entities) via the signaling channel of the SAT_X satellite makes it possible to prove a usage request (i.e. communication) emanating from the UE terminal associated with the signal-to-interference-plus-noise ratio SINR.

[0129] During a step SX80, the first satellite SAT_X determines a cooperation criterion COOP_CRIT. The criterion COOP_CRIT conditions the initiation of cooperation by the first satellite SAT_X with the second satellite. In particular, the first satellite SAT_X thus determines in step SX80 whether cooperation is necessary.

[0130] A first example of implementation of step SX80 is described here. Following receipt of the BOOST usage request in step SX70, the first satellite SAT_X determines that cooperation is required and, based on the COOP_DIM information, sends a COOP_QUERY cooperation request to the second satellite SAT_Y. Receiving the usage request is, according to this first example, sufficient to verify the COOP_DIM cooperation criterion and implement cooperation.

[0131] In a second example, the first satellite SAT_X experiences a peak load (i.e., an increase in data throughput) over a given period of time. In this example, the first satellite SAT_X does not have sufficient frequency resources to communicate all of the data to the terminals, and determines that cooperation is necessary.

[0132] More generally, the cooperation criterion COOP_CRIT can be determined by the first satellite SAT_X from at least one of the following information: a link budget between the first satellite SAT_X and the cell CELL; the trajectories of the satellites SAT_X and SAT_Y; the geographical coordinates defining the cell CELL.

[0133] During an SX90 step, depending on the COOP_DIM information, the first satellite SAT_X sends, to the second satellite SAT_Y, a cooperation request COOP_QUERY (received during a step SY90). The cooperation request COOP_QUERY is a request to transmit data to said at least one UE terminal. According to one embodiment, the COOP_QUERY request comprises control data, for example one or more of the following information: channels to be used, cells, transmission power levels, transmission durations, and synchronization information. In particular, the synchronization information allows the satellites SAT_X and SAT_Y to coordinate their transmissions so that the signals transmitted by the satellites are received in a synchronized manner by a receiver.

[0134] During a step SX100, according to a particular embodiment, the first satellite SAT_X receives, from the second satellite SAT_Y, a COOP_ACK response to the COOP_QUERY request (sent during a step SY100). According to one embodiment, the COOP_ACK response comprises COOP_START information indicating that the satellite SAT_Y is available to cooperate, or COOP_STOP information indicating a duration of unavailability.

[0135] During a step SX110, the first satellite SAT_X receives data DATA from the ground station GW (sent by the server SERVER, the network entity NE and the ground station GW respectively during steps SS110, SN110, and SG110). The data DATA may comprise data COOP_DATA and, also, data DATA_X. The data DATA is for example transmitted by the server SERVER included in the computer network NET.

[0136] During a step SX120, the first satellite SAT_X sends to the second satellite SAT_Y the COOP_DATA data to be transmitted to said at least one UE terminal (received during a step SY120).

[0137] During a step SX130, according to one embodiment, the first satellite SAT_X sends, to said at least one terminal UE, the data DATA_X (received during a step SU 130). The first satellite transmits the data DATA_X for example using a time-frequency block (CH1, T1). The data DATA_X may be different or identical to the data COOP_DATA.

[0138] It should be noted that if step SX130 is not implemented, then the intersatellite cooperation is of the relay type; otherwise, if step SX130 is implemented, then the intersatellite cooperation is of the CoMP or carrier aggregation type as previously described with reference to FIG. 1.

[0139] During a step SY140, the second satellite SAT_Y sends, to said at least one UE terminal, the COOP_DATA data. According to one embodiment, the second satellite SAT_Y sends the COOP_DATA data using a time-frequency block (CH1, T1) identical to the time-frequency block used by the first satellite SAT_X to send the DATA_X data; and according to another embodiment, the second satellite SAT_Y sends the COOP_DATA data using a different time-frequency block (CH2, Tl).

[0140] If, during step SY140, the second satellite SAT_Y uses a time-frequency block (CH1, Tl) identical to the time-frequency block used by the first satellite SAT_X, then the inter-satellite cooperation is of the CoMP type as previously described with reference to FIG. 1. If, during step SY140, the second satellite SAT_Y uses a time-frequency block (CH2, Tl) different from the time-frequency block used by the first satellite SAT_X, then the inter-satellite cooperation is of the carrier aggregation type as previously described with reference to FIG. 1.

[0141] Figure 3 represents, in flowchart form, steps of a communication method according to one embodiment of the invention.

[0142] According to an embodiment illustrated by Figure 3, the communication system implements a method for tracking resource usage to communicate with said at least one UE terminal. This embodiment in particular makes it possible to achieve reliable and precise traceability of the resources used during inter-satellite cooperation to communicate data to a terminal.

[0143] This embodiment can of course be combined with the four embodiments previously described, in particular the embodiments described with reference to figures 1 and 2. This embodiment thus makes it possible to monitor resource usage during cooperation between network devices, in particular cooperation of the relay, CoMP, carrier aggregation, or long intercellular transfer type.

[0144] According to this embodiment, the communication system SYS comprises at least one resource usage tracking entity. As an example, it is considered below that this tracking entity is included in the network entity NE of the system SYS. It should however be noted that this example is not limiting and other embodiments could be envisaged in which this tracking entity is included in any or each of the elements of the system SYS. In particular, the communication system SYS may comprise a plurality of tracking entities. According to one embodiment, the system SYS comprises: a first tracking entity included in the network entity NE operated by a mobile operator MNO; and a second tracking entity included in a ground station GW operated by a satellite operator SNO.

[0145] Compared to Figure 2, the method according to this embodiment further comprises at least one of the steps described below. More specifically, the steps of Figure 3 either describe additional steps compared to the steps of Figure 2, or specify the implementation of the steps of Figure 2 according to embodiments of the invention.

[0146] During a step SG10, the ground station GW receives, from a certified entity NE, one or more TDD resource delegation authorizations comprising respectively a public key associated with the certified network entity NE (sent during a step SN10). The TDD authorizations (i.e. delegation right) indicate resources that can be exploited by network devices, in particular the satellites SAT_X and SAT_Y, to implement cooperations between network devices in order to communicate with terminals.

[0147] Hereinafter, the reference signs beginning with T designate information or a token type message comprising, according to one embodiment, a signature making it possible to authenticate the author of a data block and to verify its integrity. A token also makes it possible to identify this data block which is therefore not retransmitted, if it is assumed to be known to the recipient. In particular, the COOP_TICKET messages, described hereinafter with reference to steps SX150 and SU160, group together the different tokens in order to have at least the signatures of the network devices participating in the cooperation, the associated data (i.e. transmitted during the cooperation) not necessarily being included in the COOP_TICKET messages.

[0148] During a step SG20, the ground station GW sends the TDD_X, TDD_Y grants to the satellites SAT_X and SAT_Y (received during steps SX20 and SY20). For example, a TDD grant may be issued by the network entity NE operated by a mobile operator MNO that owns a certain frequency spectrum. In this example, through the TDD grant, a mobile operator MNO authorizes a satellite operator SNO to exploit all or part of the spectrum owned by the MNO to communicate data to UE terminals.

[0149] During a step SG40, the ground station GW receives, from the certified entity NE, one or more authorizations for using TDU resources comprising respectively a signature determined from a private key associated with the certified entity NE (sent during a step SN40). The TDU authorizations (i.e. usage rights) indicate resources that can be used by network devices, in particular the satellites SAT_X and SAT_Y, to communicate with terminals.

[0150] During a step SG60, the ground station GW sends the authorizations TDU_X, TDU_Y to the satellites SAT_X and SAT_Y Y (received during steps SX60 and SY60). For example, a TDU authorization may be issued by a mobile operator MNO and indicate the usable frequency spectra. According to this example, a mobile operator MNO may authorize, by a TDU_X authorization, the first satellite SAT_X to use a frequency channel between 3.510 GHz and 3.529 GHz to communicate with terminals.

[0151] According to one embodiment, the signature of a message is obtained by encrypting a hash of the message with the private key. Thus, upon receipt of the message, the recipient simply needs to decrypt the signature of the message with the sender's public key, then compare the signature decrypted to a hash of the received message to ensure the authenticity and integrity of the message.

[0152] The SAT_X and SAT_Y satellites respectively perform an authentication step SX61 and SY61 of the TDD spectrum usage authorizations based on the signatures and public keys received, for example those of the TDDs. This embodiment makes it possible to reliably and securely control the exploitation of resources, particularly during intersatellite cooperation.

[0153] Hereinafter, TUCP and TUDP information designate evidence of usage of resources used by network devices to communicate with at least one terminal. More specifically, TUCP and TUDP information designate respectively evidence of usage of resources used to communicate control data and to communicate application data.

[0154] During a step SX90, the first satellite SAT_X sends to the second satellite SAT_Y: a cooperation request COOP_QUERY; a TUCP_X information; and a TDU_X authorization (received during a step SY90). The TUCP_X information indicates, for example, a number of time-frequency blocks used by the first satellite SAT_X to transmit the COOP_QUERY request; and the TDU_X authorization is used to indicate the spectrum used.

[0155] During a step SX100, according to a particular embodiment, the first satellite SAT_X receives from the second satellite SAT_Y: a COOP_ACK response; TUCP_Y information; and a TDU_Y authorization (sent during a step SY100). For example, the TUCP_Y information indicates a number of time-frequency blocks used by the second satellite SAT_Y to transmit the COOP_ACK response; and the TDU_Y authorization is used to indicate the spectrum used.

[0156] During a step SX120, the first satellite SAT_X sends to the second satellite SAT_Y: COOP_DATA data; and TUDP_X information (received during a step SY120). For example, the TUDP_X information indicates a number of time-frequency blocks used by the first satellite SAT_X to transmit the COOP_DATA data.

[0157] During a step SX130, according to one embodiment, the first satellite SAT_X sends to said at least one UE terminal: the data DATA_X; the authorizations TDD_X and TDU_X; and information TUDP_X (received during a step SU130). For example, the information TUDP_X indicates a number of time-frequency blocks used by the first satellite SAT_X to send the data COOP_DATA and the data DATA_X; and the authorizations TDD_X, TDU_Y allow the receiver to authenticate the information transmitted as well as to identify the resources used by the first satellite SAT_X.

[0158] During a step SY140, the second satellite SAT_Y sends to said at least one UE terminal: the COOP_DATA data; the TDD_Y and TDU_Y authorizations; and TUCP_Y and TUDP_Y information (received during a step SU 140). For example, the TUCP_Y and TUDP_Y information indicates a number of time-frequency blocks used by the second satellite SAT_Y to send the COOP_ACK response and the COOP_DATA data; and the TDD_Y, TDU_Y authorizations allow the receiver to authenticate the transmitted information as well as to identify the resources used by the second satellite SAT_Y.

[0159] During a step SY150, the second satellite SAT_Y sends, to the first satellite SAT_X, a COOP_TICKET message comprising: the TDD_Y and TDU_Y authorizations; and TUCP_Y and TUDP_Y information. For example, the TUCP_Y and TUDP_Y information indicates all or part of the resources used by the second satellite SAT_Y during the cooperation.

[0160] During a step SX150, according to a particular embodiment, the first satellite SAT_X sends, to the second tracking entity included in the ground station GW, a COOP_TICKET message comprising: the authorizations TDD_X, TDD_Y, TDU_X and TDU_Y; and information TUCP_X, TUCP_Y, TUDP_X and TUDP_Y (received and transmitted by the ground station GW during a step SG 150). In this way, the tracking entity included in the ground station GW is able to track and accurately account for the resources used by the first SAT_X and the second satellite SAT_Y to communicate data to said at least one UE terminal.

[0161] During a step SU160, following receipt of the data DATA_X and COOP_DATA, said at least one UE terminal sends a COOP_TICKET message to the first tracking entity included in the network entity NE (received during a step SN160). The COOP_TICKET message comprises: the authorizations TDD_X, TDD_Y, TDU_X and TDU_Y; and information TUCP_X, TUCP_Y, TUDP_X and TUDP_Y, received from the satellites SAT_X and SAT_Y. In this way, the tracking entity included in the network entity NE is able to track the resources used by the satellites to communicate data to the terminal and to prove that a communication has actually been carried out.

[0162] Figure 4 represents, in flowchart form, steps of a communication method according to one embodiment of the invention.

[0163] According to a first embodiment, the inter-satellite cooperation is of the relay type, the second satellite SAT_Y being operated as a relay between the first satellite SAT_X and said at least one UE terminal. In this embodiment, the monitoring of the resources used by the satellites SAT_X and SAT_Y to communicate COP_DATA data to said at least one UE terminal can be implemented in the following manner.

[0164] During a step SY90, the second satellite SAT_Y receives, from the first satellite SAT_X: a cooperation request COOP_QUERY; and information TUCP_X relating to the resources used by the first satellite SAT_X to send the cooperation request COOP_QUERY.

[0165] During a step SY120, the second satellite SAT_Y receives, from the first satellite SAT_X: COOP_DATA data to be transmitted to said at least one UE terminal; and TUDP_X information relating to the resources used by the first satellite SAT_X to send the COOP_DATA data.

[0166] During a step SY140, the second satellite SAT_Y sends, to said at least one terminal: the data COOP_DATA; and information TUCP_X, TUCP_Y, TUDP_X, and TUDP_Y. The information TUCP_Y and TUDP_Y relates to the resources used by the second satellite SAT_Y to send a response COOP_ACK to the request COOP_QUERY and to communicate the data COOP_DATA.

[0167] In this embodiment, a UE terminal receives the COOP_DATA data as well as the information relating to the resources used by the two satellites SAT_X and SAT_Y to communicate this data. In particular, the UE terminal sends the received information to the tracking entity NE. The tracking entity NE is thus able to trace the implementation of the communication and the inter-satellite cooperation implemented to communicate the data.

[0168] According to a second embodiment, the inter-satellite cooperation implemented by the communication system is of the CoMP type. According to this embodiment, the first satellite SAT_X and second satellite SAT_Y are used to transmit COOP_DATA data in a coordinated manner to said at least one UE terminal. This embodiment makes it possible to increase the power of the signal received by the UE terminals and thus to improve the communication performance in terms of coverage and reliability.

[0169] During a step SY90, the second satellite SAT_Y receives, from the first satellite SAT_X: a cooperation request COOP_QUERY; and information TUCP_X relating to the resources used by the first satellite SAT_X to send the cooperation request COOP_QUERY.

[0170] During a step SY100, the second satellite SAT_Y sends, to the first satellite SAT_X: a COOP_ACK response; and TUDP_Y and TUCP_Y information relating to the resources used by the second satellite SAT_Y to send the COOP_QUERY response and the COOP_DATA data.

[0171] During a step SY120, the second satellite SAT_Y receives, from the first satellite SAT_X: COOP_DATA data to be transmitted to said at least one UE terminal; and information TUCP_X, TUCP_Y, TUDP_X, and TUDP_Y relating to the resources used by the two satellites SAT_X and SAT_Y to communicate the COOP_DATA data to said at least one UE terminal. Tl

[0172] During a step SX130, the first satellite SAT_X sends, to said at least one UE terminal: COOP_DATA data; and the information TUCP_X, TUCP_Y, TUDP_X, and TUDP_Y relating to the resources used by the two satellites SAT_X and SAT_Y to communicate the COOP_DATA data to said at least one UE terminal.

[0173] During a step SY140, the second satellite SAT_Y sends, to said at least one UE terminal: the data COOP_DATA; and the information TUCP_X, TUCP_Y, TUDP_X, and TUDP_Y relating to the resources used by the two satellites SAT_X and SAT_Y to communicate the data COOP_DATA to said at least one UE terminal.

[0174] In this embodiment, a terminal UE receives the COOP_DATA data from the two satellites SAT_X and SAT_Y as well as the information relating to the resources used by the two satellites SAT_X and SAT_Y to communicate this data. In particular, the terminal UE sends the received information to the tracking entity NE. The tracking entity NE is thus able to trace the implementation of the communication and the inter-satellite cooperation implemented to communicate the data.

[0175] According to a third embodiment, the inter-satellite cooperation implemented by the communication system is of the carrier aggregation type. In this mode, the first SAT_X and the second satellite SAT_Y are used to simultaneously send, to said at least one UE terminal, DATA_X and COOP_DATA data using different frequency resources. This embodiment makes it possible to implement frequency multiplexing, and thus to improve the transmission rate.

[0176] During a step SY90, the second satellite SAT_Y receives, from the first satellite SAT_X: a cooperation request COOP_QUERY; and information TUCP_X relating to the resources used by the first satellite SAT_X to send the cooperation request COOP_QUERY.

[0177] During a step SY100, the second satellite SAT_Y sends, to the first satellite SAT_X: a COOP_ACK response; and TUDP_Y and TUCP_Y information relating to the resources used by the second satellite SAT_Y to send the COOP_QUERY response and the COOP_DATA data.

[0178] During a step SY120, the second satellite SAT_Y receives, from the first satellite SAT_X: COOP_DATA data to be transmitted to said at least one UE terminal; and information TUDP_X relating to the resources used by the first satellite SAT_X to communicate the COOP_DATA data to the second satellite SAT_Y.

[0179] During an SX130 step, the first satellite SAT_X sends, to at least one terminal EU: DATA_X data; and TUCP_X and TUDP_X resource information used by the first satellite SAT_X to communicate the DATA_X data to said at least one UE terminal.

[0180] During a step SY140, the second satellite SAT_Y sends, to said at least one UE terminal: the COOP_DATA data; and the TUCP_Y and TUDP_Y information relating to the resources used by the second satellite SAT_Y to communicate the COOP_DATA data to said at least one UE terminal.

[0181] In this embodiment, a UE terminal receives, from the first satellite SAT_X, the DATA_X data as well as the information relating to the resources used by the first satellite SAT_X to communicate the DATA_X data. In addition, the UE terminal receives, from the second satellite SAT_Y, the COOP_DATA data as well as the information relating to the resources used by the second satellite SAT_Y to communicate the COOP_DATA data. Following the receptions, the UE terminal sends the received information to the tracking entity NE.

[0182] Figure 5 schematically represents an example of software and hardware architecture of a communication system according to one embodiment of the invention.

[0183] As illustrated in Figure 5, according to one embodiment, the ground station GW comprises at least one of the following modules: a communication module COM_NET_GW configured to communicate with the communication network NET; and a communication module COM_GW_SAT configured to communicate with at least one of the satellites SAT_X and SAT_Y.

[0184] As illustrated in Figure 5, according to one embodiment, the satellites SAT_X and SAT_Y respectively comprise at least one of the following modules: a communication module COM_GW_SAT configured to communicate with the ground station GW; a communication module COM_SAT_SAT configured to communicate with at least one other satellite; and a communication module COM_SAT_UE configured to communicate with said at least one terminal UE.

[0185] As illustrated by Figure 5, according to one embodiment, a said UE terminal comprises at least one of the following modules: a COM_SAT_UE communication module configured to communicate with at least satellites SAT_X and SAT_Y; and a COM_UE_NET communication module configured to communicate with the network.

[0186] According to one embodiment, one or more elements of the communication system SYS respectively have the hardware architecture of a computer. Consider an element ELT of the communication system SYS. According to this embodiment, the element ELT comprises a processor PROC, a random access memory, a read-only memory MEM, and a non-volatile memory. The memory MEM constitutes an information medium in accordance with the invention, readable by a computer and on which a computer program PROG is recorded. The program The computer program PROG comprises instructions for implementing the steps performed by the ELT element of a method according to the invention, when the computer program PROG is executed by the processor PROC. The computer program PROG defines the functional modules represented below by Figure 6, which rely on or control the hardware elements of the latter.

[0187] Figure 6 schematically represents an example of functional architecture of a communication system according to one embodiment of the invention.

[0188] The following reference signs make it possible, for each of the modules of the communication system, to identify the element comprising this module: The references beginning with MX for the modules of the first satellite SAT_X; MY for the second satellite SAT_Y; MU for said at least one terminal UE; and MN for the modules of the network entity NE.

[0189] As illustrated in Figure 6, according to one embodiment, the first satellite SAT_X and the second satellite SAT_Y respectively comprise at least one of the following modules:

[0190] a MX_RCV_DATA receiving module to receive DATA data;

[0191] an MX_SND_QUERY send module to send the COOP_QUERY request;

[0192] an MX_RCV_ACK receiving module to receive the COOP_ACK response;

[0193] a MX_SND_COOP sending module to send COOP_DATA data;

[0194] a MX_SND_DATA sending module to send the DATA_X data;

[0195] an MX_COM_TUDP communication module for sending and / or receiving TDD, TDU, TUCP and TUDP information;

[0196] an MX_AUTH authentication module to authenticate TDU information; and

[0197] an MX_COM_TICKET communication module to receive and / or send the COOP_TICKET message.

[0198] As illustrated in Figure 6, according to one embodiment, the second satellite SAT_Y comprises respectively at least one of the following modules:

[0199] a MY_RCV_QUERY receiving module to receive the COOP_QUERY request;

[0200] a MY_SND_ACK sending module to send the COOP_ACK response;

[0201] a MY_RCV_COOP receiving module to receive COOP_DATA data; and

[0202] a MY_SND_COOP sending module to send COOP_DATA data.

[0203] a MY_COM_TUDP communication module for sending and / or receiving TDD, TDU, TUCP and TUDP information;

[0204] a MY_AUTH authentication module to authenticate TDU information; and

[0205] a MY_SND_TICKET sending module to send the COOP_TICKET message.

[0206] As illustrated by Figure 6, according to one embodiment, a said UE terminal comprises at least one of the following modules:

[0207] a MU_RCV_DATA receiving module for receiving DATA_X and COOP_DATA data and TDD, TDU, TUCP, and TUDP information; and

[0208] a MU_SND_TICKET sending module to send the COOP_TICKET message.

[0209] As illustrated in Figure 6, according to one embodiment, the tracking entity NE comprises a receiving module MN_RCV_TICKET for receiving the COOP_TICKET message.

[0210] The term module can correspond to a software component as well as to a hardware component or a set of hardware and software components, a software component itself corresponding to one or more computer programs or subroutines or more generally to any element of a program capable of implementing a function or a set of functions as described for the modules concerned. In the same way, a hardware component corresponds to any element of a hardware assembly capable of implementing a function or a set of functions for the module concerned (integrated circuit, smart card, memory card, etc.).

[0211] It should be noted that the order in which the steps of a method as described above are carried out, in particular with reference to the attached drawings, constitutes only an example of an embodiment without any limiting character, variants being possible. Furthermore, the reference signs are not limiting of the scope of the protection, their sole function being to facilitate the understanding of the claims.

[0212] A person skilled in the art will understand that the embodiments and variants described above constitute only non-limiting examples of implementation of the invention. In particular, a person skilled in the art may envisage any adaptation or combination of the embodiments and variants described above in order to meet a very specific need.

[0213] As described above, the present invention applies in particular to satellite communication systems. However, it is important to note that the invention also applies to all types of communication systems and networks, including terrestrial, satellite or aircraft communication systems. For example, the invention can be applied to terrestrial or aerial mobile telephone cellular networks, or even to wireless local area networks.

Claims

Claims

1. Method implemented by a network device (SAT_X, SAT_Y) for tracking resource usage for communicating with at least one terminal (UE), the method comprising: sending (SX120, SX130, SY140), to said at least one terminal (UE), data (DATA_X, COOP_DATA); sending (SX120, SX130, SY140), to a tracking entity (GW) and / or said at least one terminal (UE), one or more proofs of usage (TUCP, TUDP) indicating resources used by said network device (SAT_X, SAT_Y) to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE); and a sending (SX120, SX130, SY140), to the monitoring entity (GW) and / or said at least one terminal (UE), of one or more proofs of use (TUCP, TUDP) indicating resources used by at least one other network device (SAT_Y, SAT_X) to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE).

2. Method according to claim 1 in which said one or more proofs of use (TUCP, TUDP) are signed by a private key associated with a certified entity (NE).

3. Method according to claim 1 or 2 wherein said one or more proofs of use (TUCP, TUDP) indicate: frequency resources used to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE); and / or time-frequency resources used (TUDP, TUCP) to communicate application data (DATA_X, COOP_DATA) to said at least one terminal (UE) and associated control data (COOP_QUERY, COOP_ACK); and / or a quantity of energy resources consumed to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE).

4. Method according to one of claims 1 to 3 in which said network device (SAT_X) sends (SX120) all or part of said data (COOP_DATA) to said at least one terminal (UE) via another network device (SAT_Y).

5. Method according to claim 4 in which said sending (SX120) of all or part of said data (COOP_DATA) to said at least one terminal (UE) by via said at least one other network device (SAT_Y) is triggered (SX80) following a reception (SX70) of a usage request message (BOOST) received from said at least one terminal (UE).

6. Method according to one of claims 1 to 5 wherein the sending of said data (DATA_X, COOP_DATA) by said network device (SAT_X) to said at least one terminal (UE) comprises: sending (SX130), to said at least one terminal (UE), a first portion of said data (DATA_X); and sending (SX120), to at least one other network device (SAT_Y), a second portion of said data (COOP_DATA) to be transmitted to said at least one terminal (UE).

7. Method according to one of claims 4 to 6 comprising: sending (SX90), to said at least one other network device (SAT_Y), a data transmission request (COOP_QUERY) to said at least one terminal (UE), said request (COOP_QUERY) comprising one or more proofs of use (TUCP, TUDP) indicating resources used by said network device (SAT_X); and receiving (SX100), from said at least one other network device (SAT_Y), a response (COOP_ACK) comprising one or more proofs of use (TUCP, TUDP) indicating resources used by said at least one other network device (SAT_Y).

8. Method according to one of claims 1 to 7 comprising: a reception (SX20, SY20), from a certified entity (NE), of a public key associated with the certified entity (NE); a reception (SX60, SY60), from the certified entity (NE), of an authorization to use (TDU_X, TDU_Y) at least one resource comprising a signature determined from a private key associated with the certified entity (NE); and an authentication (SX61, SY61) of said authorization (TDU_X, TDU_Y) from the signature and the public key received.

9. Method implemented by a terminal (UE) for tracking resource usage for communicating with at least one network device (SAT_X, SAT_Y), the method comprising: receiving (SU120, SU130, SU140), from said at least one network device (SAT_X, SAT_Y), data (DATA_X, COOP_DATA); receiving (SU120, SU130, SU140), from said at least one network device (SAT_X, SAT_Y), one or more proofs of usage (TUCP, TUDP) indicating resources used by said at least one network device (SAT_X, SAT_Y) to communicate said data (DATA_X, COOP_DATA) to the terminal (UE); a reception (SU120, SU130, SU140), from said at least one network device (SAT_X, SAT_Y), of one or more proofs of use (TUCP, TUDP) indicating resources used by at least one other network device (SAT_Y, SAT_X) to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE); and a sending, to a monitoring entity (NE), of said proofs of use (TUCP, TUDP).

10. Network device (SAT_X, SAT_Y) for communicating with at least one terminal (UE) comprising: a sending module (MX_SND_COOP, MX_SND_DATA, MY_SND_COOP) configured to send, to said at least one terminal (UE), data (DATA_X, COOP_DATA); and a sending module (MX_COM_TUDP, MY_COM_TUDP) configured to: o send, to a tracking entity (NE) and / or said at least one terminal (UE), one or more proofs of use (TUCP, TUDP) indicating resources used by said network device (SAT_X, SAT_Y) to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE); and to send, to the monitoring entity (GW) and / or said at least one terminal (UE), one or more proofs of use (TUCP, TUDP) indicating resources used by at least one other network device (SAT_Y, SAT_X) to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE).

11. Terminal (UE) comprising: a receiving module configured to: o receive, from at least one network device (SAT_X, SAT_Y), data (DATA_X, COOP_DATA) and one or more proofs of use (TUCP, TUDP) indicating resources used by said at least one network device (SAT_X, SAT_Y) to communicate said data (DATA_X, COOP_DATA) to the terminal (UE); and to o receive, from said at least one network device (SAT_X, SAT_Y), one or more proofs of use (TUCP, TUDP) indicating resources used by at least one other network device (SAT_Y, SAT_X) to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE); and a sending module configured to send, to a tracking entity (NE), said proofs of use (TUCP, TUDP).

12. Tracking entity (NE, GW) comprising: a receiving module (MN_RCV_TICKET) configured to: o receive, from at least one network device (SAT_X, SAT_Y) and / or from at least one terminal (UE), one or more proofs of use (TUCP, TUDP) indicating resources used by said at least one network device (SAT_X, SAT_Y) to communicate data (DATA_X, COOP_DATA) to said at least one terminal (UE); and to o receive, from said at least one network device (SAT_X, SAT_Y) and / or from said at least one terminal (UE), one or more proofs of use (TUCP, TUDP) indicating resources used by at least one other network device (SAT_Y, SAT_X) to communicate said data (DATA_X, COOP_DATA) to said at least one terminal (UE).

13. System (SYS) comprising: at least one network device (SAT_X, SAT_Y) according to claim 10; and at least one terminal according to claim 11.

14. System (SYS) according to claim 13 comprising at least one tracking entity (NE, GW) according to claim 12.

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