Methods for transmitting, collecting, aggregating and processing data implemented by satellites, and corresponding master, collector, aggregator and processing satellites

Abstract

The invention relates to collaboration between a number of satellites 1-1 to 3-3. The fact that access nodes providing access to the radio access network (RAN) are deployed with splits that differ depending on requirements of a managing operator limits the possibilities and advantageousness of inter-satellite collaboration. Specifically, in the context of such collaboration, the data collected and processed by the satellites must have undergone the same processing. This is not systematically the case. It is thus necessary to apply, to the data collected by the satellites, processing operations implemented in high-level layers such as layers of level 3 or higher. This results in a long processing time and generates additional traffic load. The invention enables efficient collaboration between satellites by specifying, in a data collection request intended to be broadcast, the minimum processing that must be applied to the data collected by the collector satellites 1-1, 1-2 before they are transmitted to a master satellite 4.

Description

[0001] DESCRIPTION

[0002] TITLE: Methods of transmitting, collecting, aggregating and processing data implemented by satellites, and corresponding master, collector, aggregator and processing satellites.

[0003] Field of invention

[0004] The field of the invention is that of cloud computing.

[0005] More specifically, the invention relates to collaboration between several satellites belonging or not to the same constellation of satellites in order to improve the quality of the uplink transmission, that is to say, from a terminal to a satellite serving a cell of a communication network in which the terminal is located.

[0006] Prior art and its drawbacks

[0007] In recent years, the deployment of satellites, particularly in the form of satellite constellations consisting of several hundred to several thousand satellites in low orbit around the Earth, has been accelerating.

[0008] The objective of such deployment of satellite constellations is, among other things, to provide user terminals with high-speed access to a communications network when access to the latter via terrestrial radio access networks is not satisfactory.

[0009] A satellite constellation consists of a group of artificial satellites working together to provide a service, such as access to a communications network, by ensuring the most complete possible ground coverage of the Earth's surface to ensure continuity in the provision of this service. To this end, a satellite carries at least one access node of a radio access network interconnected to a core network whose equipment is based on the ground.

[0010] Furthermore, each satellite belonging to the same constellation circulates in an orbit chosen so that all the ground coverages of each of the satellites in the constellation complement each other.

[0011] A satellite's resources are not used continuously over time. Indeed, a satellite may be required to fly over desert areas, aquatic areas, forests, or agricultural areas, in which few, if any, user terminals are located. Thus, the radio communication resources of these satellites are free over many time slots.

[0012] In order to be able to exploit these radio communication resources, cooperation between several satellites of the same constellation or belonging to different constellations can be envisaged. Thus, a satellite belonging to a first constellation flying over an area in which there is no communication terminal to be served can share its radio communication resources with another satellite belonging to a second constellation located in a position in its orbit that does not allow it to optimally serve a given radio cell because its distance and / or its degree of inclination relative to the ground surface of this radio cell, and to the air zone attached to this surface, does not offer sufficient transmission conditions to guarantee an acceptable quality of service to the communication terminals located within this radio cell.

[0013] In order to increase transmission capacity and reduce transmission delay within a RAN radio access network, the fifth generation of radio communications standards or 5G takes advantage of the development of virtual machines and cloud computing to propose a restructured 5G access node or gNB. More specifically, such a gNB access node is divided into three units: a first unit called RU for "radio unit", a second unit called DU for "distributed unit" and a third unit called CU for "centralized unit". These three units are hardware and / or software units, these implementation choices depending on the operating constraints of RAN radio access network operators.

[0014] Most commonly, the RU is a hardware unit designed to convert radio signals sent to and from at least one antenna into a digital signal for transmission over a packet communication network. The RU handles the functions performed by the lower layer 1 or physical layer as well as the beamforming functionality by the antenna. The RU is deployed within the network access node.

[0015] The DU is, generally speaking, a software unit deployed within a server located near the RUs. This DU performs functions of the level 2 layers such as the RLC (Radio Link Control) and MAC (Medium Access Control) layers and sometimes part of the physical layer functions.

[0016] The RU unit and the DU unit are connected by means of a transport network called "fronthaul". The data exchanges carried out by means of this fronthaul comply with the eCPRI (evolved Common Public Radio Interface) protocol.

[0017] Finally, the CU, which is also a software unit, performs functions of the upper layer 2 layers such as the RRC (Radio Resource Control), SDAP (Service Data Adaptation Protocol) or PDCP (Packet Data Convergence Protocol) layers and functions of the layer 3 layers. The CU can be deployed in the cloud to allow the RAN radio access network to benefit from the advantages offered by edge computing, which allows data to be processed as close as possible to their source or destination. A single CU can manage one or more DUs, thus reducing the deployment and maintenance costs of the RAN radio access network.

[0018] Depending on the needs of an operator managing a RAN radio access network, it is interesting to distribute the execution of the physical and / or link layer functions between the RU unit and the DU unit, or even the CU unit. Such distributions are more commonly known as "splits".

[0019] There are many splits, each offering different benefits. For example, the 3GPP (Third Generation Partnership Project) standards group has defined eight splits, the most commonly used being split 7.3. In split 7.3, the cyclic prefix insertion, beamforming, IQ compression / decompression, resource element mapping, precoding, and modulation functions are performed within the RU, while scrambling, rate adaptation, and coding functions are performed by the DU.

[0020] Another example of split is split 7.2, also defined by 3GPP, in which the functions of cyclic prefix insertion, beamforming, IQ compression or decompression are performed within the RU while the functions of resource element mapping, precoding, modulation, scrambling, rate adaptation and coding are performed by the DU.

[0021] Another example of split between CU and DU is split 6, defined by 3GPP and the Small Cell Forum for short distances between the DU and the CU.

[0022] The fact that the access nodes to the radio access network are deployed according to different splits depending on the needs of the operator managing this radio access network RAN ​​limits the possibilities and the interest of a collaboration between satellites. Indeed, in the context of such a collaboration between satellites, the data collected and processed by the units of the latter must have received the same treatment. However, depending on the split implemented within the units of the access nodes on board the satellites intended to collaborate, this is not systematically the case. It is then necessary to apply to the data thus collected by these satellites processing implemented in high layers such as the level 3 layers or higher. The collected data is then processed in equipment remote from the access node.This results in longer processing times and additional traffic load in communications networks, as the data collected by the satellites has to be routed to the equipment designed to process it.

[0023] There is therefore a need for a technique to facilitate collaboration between satellites which does not have all or part of the aforementioned drawbacks.

[0024] Statement of the invention

[0025] The invention meets this need by proposing a method for transmitting data to at least one piece of equipment belonging to a communications network.

[0026] Such a data transmission method is particular in that it comprises the following steps implemented by the master satellite: - broadcasting, to at least one second satellite, called the collector satellite, of a request to collect data transported by at least one subcarrier frequency,

[0027] - collection of data transported by said at least one subcarrier frequency,

[0028] - aggregation of said collected data and data transmitted by said collecting satellite,

[0029] - transmission of aggregated data to said at least one device belonging to a communications network.

[0030] According to at least some embodiments, the data transmission method comprises receiving data from said collecting satellite. Said reception is for example carried out in response to said broadcast.

[0031] According to at least some embodiments, said at least one subcarrier frequency is allocated to at least one terminal located in a cell of a radio communication network served at least by said master satellite.

[0032] According to at least some embodiments, the collection request comprises parameters relating to said cell of said radio communication network.

[0033] According to at least certain embodiments, said collection request comprises at least one identifier of at least one first function of said at least one collecting satellite intended to be applied to the data collected prior to their transmission to the master satellite.

[0034] According to at least some embodiments, said collection request comprises an identifier of said at least one subcarrier frequency.

[0035] Thus, according to at least certain embodiments, such a data transmission method comprises the following steps implemented by the master satellite:

[0036] - broadcasting, to at least one second satellite, called the collector satellite, a request to collect data transported by said at least one subcarrier frequency, said collection request comprising an identifier of said at least one subcarrier frequency, parameters relating to said cell of the radio communication network, and at least one identifier of at least one first function of said at least one collector satellite intended to be applied to the data collected prior to their transmission to the master satellite,

[0037] - collection of data transported by said at least one subcarrier frequency,

[0038] - aggregation of said collected data and said data transmitted by said collecting satellite,

[0039] - transmission of aggregated data to said at least one device belonging to a communications network.

[0040] Such a data transmission method allows for efficient collaboration between satellites. Indeed, by specifying in the data collection request intended for broadcast the minimum processing to be applied to the data collected by the collector satellites before their transmission to the master satellite, the latter is assured of receiving only data processed in accordance with its needs independently of the splits implemented within the collector satellites. Thus, the data collected by the different satellites no longer need to be processed by equipment located further upstream in the radio access network before being retransmitted, in a suitable format, to the master satellite.

[0041] The transmission method which is the subject of the present invention, by specifying the function(s) of the RU, DU and / or CU units (for example the function(s) of the physical and / or link layers) to be applied to the data collected by a satellite, makes it possible to transmit, to the master satellite, incomplete or erroneous data from the point of view of the eCPRI protocol since they may not have had all the functions constituting the split implemented in the access node of a collector satellite applied to them. This is then referred to as a partial split.

[0042] As mentioned above, such a transmission method allows direct collaboration between satellites, with the collected data being transmitted directly between them without passing through equipment in a ground-based communications network. This has a positive impact on data collection and processing time.

[0043] By enabling direct collaboration between multiple satellites, the present invention helps improve the performance of the uplink radio access network. Indeed, it then becomes possible to take advantage of unused resources of certain satellites, particularly those in a situation of high inclination relative to a ground surface.

[0044] The implementation of such an invention also makes it possible to reduce the transmission power of the user terminals served by the master satellite. Indeed, since several satellites collaborate to collect the data transported by said at least one subcarrier frequency allocated to a user terminal, the latter can limit its transmission power without risking negatively impacting the quality of the transmission. Such a reduction in the transmission power of a terminal has the corollary effect of limiting the risk of interference impacting the antennas of the master satellite and increasing the battery life of the user terminal.

[0045] Finally, the transmission method that is the subject of the invention is of particular interest when the user terminals are connected objects with high energy constraints. In order to comply with these energy constraints, it is important to limit the number of retransmissions requested from such a connected object. By aggregating the data collected by all the collecting satellites and applying deferred decoding of the data thus aggregated, the transmission method that is the subject of the invention makes it possible to limit the number of retransmissions.

[0046] The collection request broadcast by the master satellite may further include: - information relating to the modulation and coding scheme of a radio signal intended to modulate said at least one subcarrier frequency,

[0047] - information relating to the type of modulation to be applied to said at least one subcarrier frequency.

[0048] The master satellite can specify precisely the parameters that allow other satellites to collaborate with it. Thus, only satellites meeting the criteria included in the collaboration request can decide to collect data carried by the at least one subcarrier frequency allocated to a user terminal.

[0049] In some cases, the collection request also includes an identifier of said at least one collecting satellite.

[0050] In at least some embodiments, the collection request comprises:

[0051] - an identifier of at least one third satellite, called an aggregator satellite, configured to collect and aggregate said data transmitted by said at least one collector satellite.

[0052] In at least some embodiments, the collection request further comprises at least one identifier of at least one second function of said at least one aggregator satellite intended to be applied to the aggregated data prior to their transmission to the master satellite.

[0053] Indeed, in certain circumstances, the master satellite may not be able to directly receive the data collected by the collector satellites.

[0054] In some embodiments (e.g., in such a case), the collection request also includes:

[0055] - an identifier of at least one third satellite, called an aggregator satellite, configured to collect and aggregate said data transmitted by said at least one collector satellite, and

[0056] - at least one identifier of at least one second function of said at least one aggregator satellite intended to be applied to the aggregated data prior to their transmission to the master satellite.

[0057] In such a case, the data collected by the collector satellites have, for example, had at least one of the following functions applied to them by the master satellite: cyclic prefix insertion function, beamforming function, IQ compression function, or an IQ decompression function, and resource element mapping function. However, the master satellite can only process data to which the precoding and modulation functions have been applied.

[0058] The aggregator satellite then applies at least one of the following functions: precoding function, modulation function to the data transmitted by the collector satellites, which it will have previously aggregated. The master satellite then receives data that it can process. Similarly, in certain embodiments, for example when the master satellite is not able to directly receive the data collected by the aggregator satellite, the collection request comprises:

[0059] - an identifier of at least one fourth satellite, called a processing satellite, configured to process said aggregated data transmitted by said at least one aggregator satellite.

[0060] In at least some embodiments, the collection request further comprises:

[0061] - at least one identifier of at least one third function of said at least one processing satellite intended to be applied to the data received prior to their transmission to the master satellite.

[0062] Thus, in at least some embodiments, the collection request further comprises:

[0063] - an identifier of at least one fourth satellite, called a processing satellite, configured to process said aggregated data transmitted by said at least one aggregator satellite, and

[0064] - at least one identifier of at least one third function of said at least one processing satellite intended to be applied to the data received prior to their transmission to the master satellite.

[0065] In such a case, the processing satellite then applies at least one function that has not been applied by either the collector satellite or the aggregator satellite. The master satellite then receives data that it can process for transfer to the core network.

[0066] The invention also relates to a method of collecting data

[0067] Such a collection method is particular in that it includes the following steps implemented by a second satellite, called a collector satellite:

[0068] - reception, from at least one first satellite, called the master satellite, of a request to collect data transported by at least one subcarrier frequency,

[0069] - collection of data transported by said at least one subcarrier frequency,

[0070] - processing by applying at least a first function of said collecting satellite to said collected data,

[0071] - transmission of processed data to the master satellite.

[0072] According to at least some embodiments, said at least one subcarrier frequency is allocated to at least one terminal located in a cell of a radio communication network served at least by said master satellite.

[0073] According to at least some embodiments, said collection request comprises parameters relating to said cell of the radio communication network.

[0074] According to at least some embodiments, said collection request comprises at least one identifier of said first function of said collecting satellite. According to at least some embodiments, said collection request comprises an identifier of said at least one subcarrier frequency.

[0075] Thus, in at least certain embodiments, such a collection method comprises the following steps implemented by a second satellite, called a collector satellite:

[0076] - reception, from the master satellite, of a request to collect data transported by said at least one subcarrier frequency, said collection request comprising an identifier of said at least one subcarrier frequency, parameters relating to said cell of the radio communication network, and at least one identifier of at least one first function of said collector satellite intended to be applied to the collected data,

[0077] - collection of data transported by said at least one subcarrier frequency,

[0078] - processing by applying said at least one first function to said collected data,

[0079] - transmission of processed data to the master satellite.

[0080] The invention also relates to a method for aggregating data.

[0081] Such an aggregation method is particular in that it comprises the following steps implemented by a second satellite, called an aggregator satellite:

[0082] - reception, from at least one first satellite, called the master satellite, of a request to collect data transported by at least one subcarrier frequency,

[0083] - collection of data transmitted by at least a third satellite, called a collector satellite,

[0084] - aggregation of said data collected by said at least one collecting satellite

[0085] - processing by applying at least one second function of said aggregator satellite to said aggregated data,

[0086] - transmission of processed data to the master satellite.

[0087] According to at least certain embodiments, said at least one subcarrier frequency is allocated to at least one terminal located in a cell of a radio communication network served at least by said master satellite.

[0088] According to at least some embodiments, said collection request comprises parameters relating to said cell of the radio communication network.

[0089] According to at least some embodiments, said collection request comprises at least one identifier of said second function of said aggregator satellite.

[0090] According to at least some embodiments, said collection request comprises an identifier of said at least one subcarrier frequency.

[0091] Thus, in at least certain embodiments, such an aggregation method comprises the following steps implemented by a second satellite, called the aggregator satellite: - reception, from the master satellite, of a request to collect data transported by said at least one subcarrier frequency, said collection request comprising an identifier of said at least one subcarrier frequency, parameters relating to said cell of the radio communication network, and at least one identifier of at least one second function of said aggregator satellite intended to be applied to the collected data,

[0092] - collection of data transmitted by at least one third satellite, called a collector satellite, configured to collect the data transported by said at least one subcarrier frequency and to apply at least one first function of said collector satellite to them,

[0093] - aggregation of said data collected by said at least one collecting satellite

[0094] - processing by applying said at least one second function to said aggregated data,

[0095] - transmission of processed data to the master satellite.

[0096] The invention further relates to a data processing method.

[0097] Such a processing method is particular in that it comprises the following steps implemented by a second satellite, called the processing satellite:

[0098] - reception, from at least one first satellite, called the master satellite, of a request to collect data transported by at least one subcarrier frequency,

[0099] - collection of data transmitted by at least one third satellite, called an aggregator satellite,

[0100] - processing by applying said at least one third function to said collected data,

[0101] - transmission of processed data to the master satellite.

[0102] According to at least some embodiments, said at least one subcarrier frequency is allocated to at least one terminal located in a cell of a radio communication network served at least by said master satellite.

[0103] According to at least some embodiments, said collection request comprises parameters relating to said cell of the radio communication network.

[0104] According to at least some embodiments, said collection request comprises at least one identifier of said third function of said processing satellite.

[0105] According to at least some embodiments, said collection request comprises an identifier of said at least one subcarrier frequency.

[0106] Thus, in at least certain embodiments, such a processing method comprises the following steps implemented by a second satellite, called the processing satellite:

[0107] - reception, from the master satellite, of a request to collect data transported by said at least one subcarrier frequency, said collection request comprising an identifier of said at least one subcarrier frequency, parameters relating to said cell of the radio communication network, and at least one identifier of at least one third function of said processing satellite intended to be applied to the collected data,

[0108] - collection of data transmitted by at least one third satellite, called an aggregator satellite, configured to aggregate data transmitted by at least one fourth satellite, called a collector satellite, configured to collect the data transported by said at least one subcarrier frequency and to apply at least one first function of said collector satellite to them,

[0109] - processing by applying said at least one third function to said collected data,

[0110] - transmission of processed data to the master satellite.

[0111] Another object of the invention relates to a communications satellite, called master satellite, capable of transmitting data to at least one piece of equipment belonging to a communications network.

[0112] Said master satellite comprises at least one processor configured to:

[0113] - broadcast, to at least one second satellite, called a collector satellite, a request to collect data transported by at least one subcarrier frequency,

[0114] - collect data transported by said at least one subcarrier frequency,

[0115] - aggregate said collected data and data transmitted by said collecting satellite,

[0116] - transmit the aggregated data to said at least one device belonging to a communications network.

[0117] In at least some embodiments, said master satellite comprises at least one processor configured to:

[0118] - broadcast, to at least one second satellite, called the collector satellite, a request to collect data transported by said at least one subcarrier frequency, said collection request comprising an identifier of said at least one subcarrier frequency, parameters relating to said cell of the radio communication network, and at least one identifier of at least one first function of said at least one collector satellite intended to be applied to the data collected prior to their transmission to the master satellite,

[0119] - collect data transported by said at least one subcarrier frequency,

[0120] - aggregate said collected data and said data transmitted by said collecting satellite,

[0121] - transmit the aggregated data to said at least one device belonging to a communications network.

[0122] The invention also relates to a communications satellite, called a collector satellite, capable of collecting data,

[0123] Said collecting satellite comprises at least one processor configured to:

[0124] - receive, from at least one first satellite, called the master satellite, a request to collect data transported by at least one subcarrier frequency, - collect data transported by said at least one subcarrier frequency,

[0125] - process by applying at least a first function of said collecting satellite to said collected data,

[0126] - transmit processed data to the master satellite.

[0127] In at least some embodiments, said collector satellite comprises at least one processor configured to:

[0128] - receive, from the master satellite, a request to collect data transported by said at least one subcarrier frequency, said collection request comprising an identifier of said at least one subcarrier frequency, parameters relating to said cell of the radio communication network, and at least one identifier of at least one first function of said collector satellite intended to be applied to the collected data,

[0129] - collect data transported by said at least one subcarrier frequency,

[0130] - process by applying said at least one first function to said collected data,

[0131] - transmit processed data to the master satellite.

[0132] Another object of the invention relates to a communications satellite, called an aggregator satellite, capable of aggregating data.

[0133] Said aggregator satellite comprises at least one processor configured to:

[0134] - receive, from at least one first satellite, called the master satellite, a request to collect data transported by at least one subcarrier frequency,

[0135] - collect data transmitted by at least one third satellite, called a collector satellite, aggregate said data collected by said at least one collector satellite

[0136] - process by applying at least one second function of said aggregator satellite to said aggregated data,

[0137] - transmit processed data to the master satellite.

[0138] In at least some embodiments, said aggregator satellite comprises at least one processor configured to:

[0139] - receive, from the master satellite, a request to collect data transported by said at least one subcarrier frequency, said collection request comprising an identifier of said at least one subcarrier frequency, parameters relating to said cell of the radio communication network, and at least one identifier of at least one second function of said aggregator satellite intended to be applied to the collected data,

[0140] - collect data transmitted by at least one third satellite, called a collector satellite, configured to collect the data transported by said at least one subcarrier frequency and to apply at least one first function of said collector satellite to them, aggregate said data collected by said at least one collector satellite

[0141] - process by applying said at least one second function to said aggregated data,

[0142] - transmit processed data to the master satellite.

[0143] The invention also relates to a communications satellite, called a processing satellite, capable of processing data.

[0144] Said master satellite comprises at least one processor configured to:

[0145] - receive, from at least one first satellite, called the master satellite, a request to collect data transported by at least one subcarrier frequency,

[0146] - collect data transmitted by at least one third satellite, called an aggregator satellite,

[0147] - process by applying at least one third function of said processing satellite to said collected data,

[0148] - transmit processed data to the master satellite.

[0149] In at least some embodiments, said processing satellite comprises at least one processor configured to:

[0150] - receive, from the master satellite, a request to collect data transported by said at least one subcarrier frequency, said collection request comprising an identifier of said at least one subcarrier frequency, parameters relating to said cell of the radio communication network, and at least one identifier of at least one third function of said processing satellite intended to be applied to the collected data,

[0151] - collect data transmitted by at least one third satellite, called an aggregator satellite, configured to aggregate data transmitted by at least one fourth satellite, called a collector satellite, configured to collect the data transported by said at least one subcarrier frequency and to apply at least one first function of said collector satellite to them,

[0152] - process by applying said at least one third function to said collected data,

[0153] - transmit processed data to the master satellite.

[0154] The invention finally relates to computer program products comprising program code instructions for implementing the methods as described above, when executed by a processor.

[0155] The invention also relates to a computer-readable recording medium on which computer programs are recorded comprising program code instructions for executing the steps of the methods according to the invention as described above.

[0156] Such a recording medium may be any entity or device capable of storing programs. For example, the medium may include a storage medium, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording medium, for example a USB key or a hard disk.

[0157] On the other hand, such a recording 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 other means, so that the computer programs contained therein may be remotely executable. The programs according to the invention may in particular be downloaded over a network, for example the Internet.

[0158] Alternatively, the recording medium may be an integrated circuit in which the programs are incorporated, the circuit being adapted to execute or to be used in the execution of the methods which are the subject of the invention mentioned above.

[0159] List of figures

[0160] Other aims, characteristics and advantages of the invention will appear more clearly on reading the following description, given as a simple illustrative, and non-limiting, example, in relation to the figures, among which:

[0161] [fig. 1]: this figure represents a system in which the present invention is implemented

[0162] [fig. 2]: this figure represents a diagram of the different stages of the methods of transmission and collection of data transported by at least one subcarrier frequency allocated to the terminal implemented by the different equipment constituting the access network in a first embodiment of the invention,

[0163] [fig. 3]: this figure represents a diagram of the different stages of the methods of transmission, collection, and aggregation of the data transported by at least one subcarrier frequency allocated to the terminal implemented by the different equipment constituting the access network in a second embodiment of the invention,

[0164] [fig- 4]: this figure represents a diagram of the different stages of the methods of transmission of collection, aggregation and processing of the data transported by at least one subcarrier frequency allocated to the terminal implemented by the different equipment constituting the access network in a third embodiment of the invention,

[0165] [fig- 5]: this figure represents a satellite capable of implementing all or part of the methods of transmission, collection, aggregation and processing of data transported by at least one subcarrier frequency allocated to the terminal which is the subject of the invention.

[0166] Detailed description of embodiments of the invention

[0167] The general principle of the invention is based on the collaboration between several satellites, whether or not belonging to the same constellation of satellites, in order to collect data transported by a subcarrier frequency of a radio signal allocated to a terminal located in a cell of a radio access network. More particularly, the present invention specifies in a collaboration request sent by a first satellite intended to be broadcast to other satellites, the minimum processing to be applied to the data collected by the satellites having agreed to collaborate before their transmission to the satellite having requested the collaboration, the latter is assured of receiving only data processed in accordance with its needs.

[0168] The present invention therefore allows direct collaboration between satellites, the collected data being transmitted directly between them without passing through equipment in a communications network located on the ground. This has a positive impact on the data collection and processing time.

[0169] By enabling direct collaboration between multiple satellites, the performance of the radio access network is improved for the uplink. Indeed, it then becomes possible to take advantage of unused resources of certain satellites, particularly those located in a situation of high inclination relative to a ground surface.

[0170] A system in which the present invention is implemented is now presented in relation to [fig. 1].

[0171] Such a system comprises a radio access network RAN ​​and a core network CORE interconnected with each other by means of a link established between at least one first satellite 4 and at least one GW equipment located on the ground.

[0172] In the example envisaged in Figure 1, the RAN access network comprises a plurality of satellite constellations const-1, const-2, const-3 placed in orbit around the Earth or any other set of stars (for example Earth and moon), at different altitudes. It will be understood that a RAN access network can comprise several dozen satellite constellations.

[0173] The first constellation of const-1 satellites includes three satellites 1-1, 1-2 and 1-3. Of course, such a constellation of const-1 satellites can include up to several thousand satellites.

[0174] The second satellite constellation, Const-2, consists of two satellites, 2-1 and 2-2. Of course, such a constellation, Const-2, can also consist of up to several thousand satellites.

[0175] Finally, the third satellite constellation const-3 also includes three satellites 3-1, 3-2 and 3-3. Of course, such a constellation of satellites const-3 can, just like the satellite constellations const-1 and const-2, include up to several thousand satellites.

[0176] The RAN radio access network also comprises here a fourth constellation const-4 comprising a single satellite 4. Of course, such a constellation of const-4 satellites can also comprise up to several thousand satellites. The RAN radio access network also comprises a plurality of cells, four of which, cell 1, cell 1, cell 3, cell 4, are represented in FIG. 1. Each cell cell 1, cell 1, cell 3, cell 4, of the RAN radio access network is served by at least one satellite belonging to the RAN radio access network, for a given duration corresponding to the time of overflight of the cell by said satellite. In the remainder of this document, only cell cell 2 is considered for the purpose of simplification. Similarly, in the remainder of this document, it is considered that cell cell 2 is served by satellite 4.

[0177] An EU terminal, such as a smartphone, a drone, a car or even an IoT sensor for example, is located in cell-2 and has established a link with satellite 4.

[0178] In such a system, a gNB access node to the radio access network is divided into three units: a first unit called RU for "radio unit", a second unit called DU for "distributed unit" and a third unit called CU for "centralized unit". These three units are hardware and / or software units, these implementation choices depending on the operating constraints of the RAN radio access network operators.

[0179] Most commonly, the RU is a hardware unit designed to convert radio signals sent to and from at least one antenna into a digital signal for transmission over a packet communication network. The RU handles the functions performed by the lower layer 1 or physical layer as well as the beamforming functionality by the antenna. The RU is deployed within the network access node.

[0180] The DU is, generally speaking, a software unit deployed within a server located near the RUs. This DU performs functions of the level 2 layers such as the RLC (Radio Link Control) and MAC (Medium Access Control) layers and sometimes part of the physical layer functions.

[0181] The RU unit and the DU unit are connected by means of a transport network called "fronthaul". The data exchanges carried out by means of this fronthaul comply with the eCPRI (evolved Common Public Radio Interface) protocol.

[0182] Finally, the CU, which is also a software unit, performs functions of the upper layer 2 layers such as the RRC (Radio Resource Control), SDAP (Service Data Adaptation Protocol) or PDCP (Packet Data Convergence Protocol) layers and functions of the layer 3 layers. The CU can be deployed in the cloud to allow the RAN radio access network to benefit from the advantages offered by edge computing, which allows data to be processed as close as possible to their source or destination. A single CU can manage one or more DUs, thus reducing the deployment and maintenance costs of the radio access network.

[0183] RAN. Depending on the needs of an operator managing a RAN radio access network, it is advantageous to distribute the execution of the physical and / or link layer functions between the RU and the DU. Such distributions are more commonly known as "splits".

[0184] According to a particular embodiment of the system illustrated in [fig. 1], the satellites 1-1 to 1-3, 2-1 and 2-2, 3-1 to 3-3 and 4 carry an RU unit and / or a DU unit. The CU unit is itself carried in equipment 5 of the access network located on the ground.

[0185] [Fig. 2] represents a diagram of the different stages of the methods of transmission and collection of data transported by at least one subcarrier frequency allocated to the terminal implemented by the different equipment constituting the RAN access network in a first embodiment of the invention.

[0186] In the implementation example described below, satellite 4, called master satellite, is the satellite serving cell 2. In other words, a terminal UE located in cell 2 wishing to establish a communication with another terminal or wishing to be provided with a service, such as for example, a content provision service (not shown in the figures) attaches to the RAN radio access network by establishing a radio link with a gNB access node of the RAN radio access network serving cell 2, in other words with the gNB access node embedded in satellite 4. As described with reference to FIG. 1, master satellite 4 embeds a RU unit and / or a DU unit constituting the gNB access node.

[0187] Thus, during a first step E1, the master satellite 4 obtains information relating, among other things, to a value of the transmission power of the UE terminal, to the radio environment in which the UE terminal is located, to a value of the variance of the “shadowing” impacting the UE terminal or to characteristic values ​​such as the reception gain of the satellites 1-1 to 1-3. Optionally, the information provided to the master satellite 4 may indicate an optimization of at least one antenna of the UE terminal, such as for example an identifier of a cardinal sector of the antenna of the UE terminal to be favored in transmission, in order to increase the value of the power received by a satellite picking up the radio signal transmitted by the user terminal.

[0188] Finally, the information provided to the master satellite 4 further comprises an identifier of at least one FSP subcarrier frequency allocated to the terminal for communicating with the master satellite and at least one index of a modulation and coding table used by the UE terminal to modulate and code the FSP subcarrier frequency, as well as the type of modulation applied such as for example QAM (Quadrature Amplitude Modulation in English) or QPSK (Quadrature Phase-Shift Keying in English). In order to determine whether the reception quality of the radio signals transmitted by the UE terminal is satisfactory or not, the master satellite 4 determines whether it is capable of offering the reception rate Du requested by the UE terminal for a given transmission.

[0189] To do this, master satellite 4 performs the following calculation: let Ns be the number of antenna beams (or spots) available to master satellite 4, or Ne the number of FSP subcarrier frequenciesC that an antenna beam can capture, or Nt = Nc*Ns the total number of FSP subcarrier frequencies t that can be received by the master satellite 4, or Nu the number of FSP subcarrier frequencies U received by the master satellite 4, or Nue the number of FSP subcarrier frequencies UC captured by a given antenna beam, let Nf = Nc-Nuc be the number of subcarrier frequencies that can still be captured by an antenna beam of the master satellite 4, let Pd be the value of the reception power of the subcarrier frequency captured by a destination antenna beam, let Pf be the value of the reception power of the subcarrier frequency captured by an antenna beam close to the destination antenna beam, let Doffert = W.log2(l+ Pd / Nth) be the reception rate offered tau to the UE terminal by the destination antenna beam, Nth being the value of the thermal noise,

[0190] If Doffert < Du,

[0191] SO

[0192] As long as Doffert< Du the master satellite 4 requests from an antenna beam neighboring the destination antenna beam the allocation of a subcarrier frequency in order to achieve the rate Du. This subcarrier frequency belongs to a subset of subcarrier frequencies allocated by the master satellite 4 to the UE terminal so that the latter can transmit data.

[0193] If an antenna beam adjacent to the destination antenna beam has a free subcarrier frequency Nf then

[0194] Allocation of this subcarrier frequency to the UE terminal:

[0195] SNRcomp = (Sum_Nf Pf + Pd) / Nth

[0196] Dcomp = W.log2(l+SNRcomp)

[0197] Doffert = Dcomp

[0198] Otherwise (an antenna beam close to the destination antenna beam has no free subcarrier frequency: Nf = 0)

[0199] FinSi application rejected

[0200] End As Long As

[0201] If Doffert < From

[0202] Connection to the EU terminal

[0203] Otherwise

[0204] EU terminal connection accepted.

[0205] When the reception quality of the radio signals transmitted by the terminal UE is not satisfactory, the master satellite 4 generates, in a step E2, a collection request req-coll. Such a collection request req-coll includes, among other things:

[0206] • information relating to the duration of the collection,

[0207] • a start time and possibly an end time for the collection,

[0208] • information relating to a roaming policy negotiated between the radio access network operator and an operator of another radio access network to which the terminal may be required to attach itself,

[0209] • an identifier of one or more FSPj subcarrier frequencies that satellites agreeing to collaborate can capture,

[0210] • an identifier of at least one index of a modulation and coding table (Modulation and Coding Scheme in English), and

[0211] • a type of modulation applied by the UE terminal to the FSP subcarrier frequency intended to be transmitted: NR QPSK, 16 QAM, 64 QAM, 256 QAM, etc.

[0212] Once the collection request req-coll has been generated, the master satellite searches for at least one other satellite that can receive the subcarrier frequency FSP, identified in the collection request req-coll, transmitted by the UE terminal. The master satellite 4 can carry out such a search for other satellites in order to be able to collect the data transmitted by the UE terminal while another satellite belonging to the constellation const-4, to which the master satellite 4 also belongs, is in position to be able to serve the cell cell-2 in which the user terminal is located.

[0213] To this end, the master satellite 4 broadcasts the collection request req-coll during a step E3.

[0214] In order to ensure that the data collected by the satellites respond favourably to the req-coll collection request, the latter specifies the function(s) of the physical and / or link layer, for example, which must be applied to the FSP subcarrier frequency by a satellite responding favourably to the req-coll collection request before their transmission to the master satellite 4. Thus, the latter is assured of only receiving data processed in accordance with its needs independently of the splits implemented within the other satellites.The fact that the master satellite 4 explicitly announces the function(s) of the physical and / or link layer to be applied to the FSP subcarrier frequency makes it possible for the satellites responding favourably to the req-coll collection request to transmit incomplete or erroneous data from the point of view of the eCPRI protocol since they may not have had all the functions constituting the split implemented in the access node of such a satellite applied to them.

[0215] Thus, for example, the collection request req-coll broadcast by the master satellite 4 during step E3 indicates that the master satellite 4 wishes to receive data that has been processed by an IQ decompression function.

[0216] In a step E4, the different satellites 1-1, 1-2 and 1-3 intercept the collection request req-coll.

[0217] In a step E5 which may be consecutive to step E4 or prior to step E1, the satellites 1-1, 1-2 and 1-3 broadcast information relating to their availability such as for example a value of the charge of their battery, their flight plan, a list of subcarrier frequencies FSPj which they can receive, etc. More particularly, the satellites 1-1, 1-2 and 1-3 announce which splits or partial splits they support. Thus, the master satellite 4 has the information allowing it to know which satellite 1-1, 1-2 or 1-3 supports a partial split delivering data having been processed for example by an IQ decompression function, and therefore by all the preceding physical layer functions, i.e. the cyclic prefix insertion and beamforming functions. In the chosen example, satellites 1-1 and 1-2 support the requested partial split and can therefore meet the needs of master satellite 4.Satellites 1-1 and 1-2 are then called collector satellites.

[0218] In order to ensure that the reception rate Du requested by the UE terminal for a given transmission is reached, the master satellite performs the following calculation: let Ns be the number of antenna beams (or spots) available to a 1-1, 1-2 satellite, or Ne the number of subcarrier frequencies FSP C that an antenna beam can capture, or Nt = Nc*Ns the total number of FSP subcarrier frequencies t that a 1-1, 1-2 satellite can pick up, or Nu is the number of FSP subcarrier frequencies U received by a satellite 1-1, 1-2, or Nue the number of FSP subcarrier frequencies UC captured by a given antenna beam, let Nms be the number of antenna beams (or spots) available to the master satellite 4, or Nmc be the number of FSP subcarrier frequencies cthat can be captured by an antenna beam of master satellite 4, i.e. Nmt = Nmc*Nms the total number of FSP subcarrier frequencies t that can be received by the master satellite 4, or Nmu the number of FSP subcarrier frequencies U captured by the master satellite 4, or Nmf = Nmcs-Nmu the number of subcarrier frequencies captured by a beam of antennas of the master satellite 4, or Nmuc the number of FSP subcarrier frequencies UCcaptured by a given antenna beam of the master satellite 4, let Pd be the value of the reception power of the sub-carrier frequency captured by a destination antenna beam of the master satellite 4, let Pf be the value of the reception power of the sub-carrier frequency captured by an antenna beam of one of the collector satellites 1-1, 1-2, let Doffert = W.log2(l+ Pd / Nth) the reception rate offered tau to the UE terminal by the collector satellites 1-1, 1-2 and the master satellite 4, Nth being the value of the thermal noise.

[0219] If Doffert < From

[0220] SO

[0221] As Long As Offered < From

[0222] Master satellite 4 requests allocation of additional FSP subcarrier frequencies to collector satellites 1-1, 1-2 in order to achieve throughput Du. This subcarrier frequency belongs to a subset of subcarrier frequencies allocated by the recipient to the UE terminal so that the latter can transmit data.

[0223] If one of the collector satellites 1-1, 1-2 has antenna beams which have unused subcarrier frequencies (Nr unused subcarrier frequencies):

[0224] SO

[0225] Allocation of these subcarrier frequencies

[0226] Throughput offered by master satellite 4 in cooperation with collector satellites 1-1, 1-2

[0227] Collector 1-1 = W.log2(l+ Sum_Nr (Pr) / Nth)

[0228] Collector 1-2 = W.log2(l+ Sum_Nr (Pr) / Nth)

[0229] Doffert = Doffert + Dcollector 1-1+Dcollector 1-2+...

[0230] Otherwise (the collecting satellite does not have free subcarrier frequencies: Nr = 0)

[0231] Request rejected

[0232] FinSi

[0233] End As Long As

[0234] If Doffert < From

[0235] UE terminal connection request rejected.

[0236] Otherwise

[0237] EU terminal connection request accepted

[0238] EndIf When the master satellite 4 is assured that the throughput Du required by the UE terminal is achieved thanks to the collaboration of the collector satellites 1-1 and 1-2, data collection can then begin.

[0239] Thus, during a step E6, the collector satellites 1-1, 1-2 and the master satellite 4 capture the FSP subcarrier frequency identified in the collection request req-coll, and then apply to the FSP subcarrier frequency, in a step E7, the functions of insertion of the cyclic prefix, of beamforming, and of IQ decompression.

[0240] In a step E8, the collector satellites 1-1 and 1-2 transmit data resulting from the processing of the FSP subcarrier frequency by the cyclic prefix insertion, beamforming, and IQ decompression functions, to the master satellite 4.

[0241] The FSP subcarrier frequencies transmitted by the UE terminal and received by the collector satellites 1-1, 1-2 may have a phase shift due for example to jitter, or linked to the Doppler effect. In order to correct these effects, the collector satellites 1-1 and 1-2 use values ​​of a transmission delay between the UE terminal and each of the collector satellites 1-1 and 1-2 determined by means of control messages exchanged between the collector satellites 1-1 and 1-2 and the UE terminal in order to correct any offsets.

[0242] In a particular embodiment, the data collected by the collecting satellites 1-1 and 1-2 are stored in a cache memory of one of the functions of the physical and / or link layer prior to their processing by the latter. This makes it possible to limit the number of retransmissions requested from the UE terminal.

[0243] Upon receipt of this data collected and processed by the collector satellites 1-1, 1-2, the master satellite 4 proceeds to aggregate it with the data that it has itself collected and processed, in a step E9.

[0244] Finally, in a step E10, the master satellite 4 transmits the data thus approved to the equipment 5. The equipment 5 applies to this aggregated data functions of the level 2 layers such as the RLC (Radio Link Control) and MAC (Medium Access Control) layers before transmitting them to the GW equipment of the CORE network in a step Eli.

[0245] [Fig. 3] represents a diagram of the different stages of the methods of transmission, collection, and aggregation of the data transported by at least one subcarrier frequency allocated to the terminal implemented by the different equipment constituting the RAN access network in a second embodiment of the invention.

[0246] Just as in the first embodiment, in the implementation example described below, satellite 4, called master satellite, is the satellite serving cell 2. In other words, a terminal UE located in cell 2 wishing to establish communication with another terminal (not shown in the figures) attaches to the radio access network RAN ​​by establishing a radio link with a gNB access node of the radio access network RAN. As described with reference to FIG. 1, master satellite 4 carries a RU unit and / or a DU unit constituting the gNB access node.

[0247] In this second embodiment, at least one 2-1 satellite called an aggregator satellite participates in the collection of data transmitted by the UE terminal. The intervention of such a 2-1 aggregator satellite in the collection is of interest, for example, when certain collector satellites are unable to implement a given split or partial split.

[0248] Thus, during a first step F1, the master satellite 4 obtains information relating, among other things, to a value of the transmission power of the UE terminal, to the radio environment in which the UE terminal is located, to a value of the variance of the “shadowing” impacting the UE terminal or even and characteristic values ​​such as the reception gain of the satellites 1-1 to 1-3 and 2-1, 2-2. Optionally, the information provided to the master satellite 4 may indicate an optimization of at least one antenna of the UE terminal, such as for example an identifier of a cardinal sector of the antenna of the UE terminal to be favored in transmission, in order to increase the value of the power received by a satellite picking up the radio signal transmitted by the user terminal.

[0249] Finally, the information provided to the master satellite 4 further comprises an identifier of at least one FSP subcarrier frequency allocated to the terminal for communicating with the master satellite and at least one index of a modulation and coding table used by the UE terminal to modulate and code the FSP subcarrier frequency, as well as the type of modulation applied such as for example QAM (Quadrature Amplitude Modulation in English) or QPSK (Quadrature Phase-Shift Keying in English).

[0250] When the reception quality of the radio signals transmitted by the terminal UE is not satisfactory, the master satellite 4 generates, in a step F2, a collection request req-coll. Such a collection request req-coll includes, among other things:

[0251] • information relating to the duration of the collection,

[0252] • a start time and an end time for the collection,

[0253] • information relating to a roaming policy negotiated between the radio access network operator and an operator of another radio access network to which the terminal may be required to attach itself,

[0254] • an identifier of one or more FSPj subcarrier frequencies that satellites agreeing to collaborate can capture,

[0255] • an identifier of at least one index of a modulation and coding table (Modulation and Coding Scheme in English), and

[0256] • a type of modulation applied by the UE terminal to the FSP subcarrier frequency intended to be transmitted: NR QPSK, 16 QAM, 64 QAM, 256 QAM, etc. Once the collection request req-coll has been generated, the master satellite searches for at least one other satellite capable of capturing the FSP subcarrier frequency, identified in the collection request req-coll, transmitted by the UE terminal and at least one other satellite capable of aggregating the data collected by the collector satellites prior to their transmission to the master satellite 4. The master satellite 4 can carry out such a search while another satellite belonging to the constellation const-4, to which the master satellite 4 also belongs, is in position to be able to serve the cell cell-2 in which the user terminal is located.

[0257] To this end, the master satellite 4 broadcasts the collection request req-coll during a step F3.

[0258] In order to ensure that the data collected and then aggregated by the satellites give a favorable response to the collection request req-coll, the latter specifies for each type of satellite, collector or aggregator, the function(s) of the physical and / or link layer, for example, which must be applied to the FSP subcarrier frequency by each of them before their transmission. Thus, the master satellite 4 is assured of receiving only data processed in accordance with its needs independently of the splits implemented within the collector satellites 1-1, 1-2 and aggregator.

[0259] The fact that the master satellite 4 explicitly announces the function(s) of the physical and / or link layer to be applied to the FSP subcarrier frequency by the collector satellites 1-1 and 1-2 and then the function(s) of the physical and / or link layer to be applied to the FSP subcarrier frequency by the aggregator satellite makes it possible for the satellites giving a favorable response to the req-coll collection request to transmit incomplete or erroneous data from the point of view of the eCPRI protocol since they may not have had all of the functions constituting the split implemented in such a satellite applied to them.

[0260] Thus, by way of example, the collection request req-coll broadcast by the master satellite 4 during step F3 indicates that the master satellite 4 wishes to receive data having been processed, at the level of a collector satellite 1-1, 1-2 by a decompression function IQ, then having been processed, hereinafter partial split 1, at the level of the aggregator satellite, by a scrambling function, hereinafter partial split 2.

[0261] In a step F4, the different satellites 1-1, 1-2, 1-3, and 2-1, 2-2 intercept the collection request req-coll.

[0262] In a step F5 which may be consecutive to step F4 or prior to step F1, satellites 1-1, 1-2 and 1-3 broadcast information relating to their availability such as for example a value of the charge of their battery, their flight plan, a list of subcarrier frequencies FSPj which they can receive, etc. More particularly, satellites 1-1 to 1-3 and 2-1, 2-2 announce which splits or partial splits they support. Thus, the master satellite 4 has the information allowing it to know which satellite 1-1 to 1-3 and 2-1, 2-2 supports partial splits 1 and 2. In the example chosen, satellites 1-1, 1-2 and 2-1 respectively support partial split 1 and partial split 2 and can therefore meet the needs of the master satellite 4. Satellites 1-1 and 1-2 are then called collector satellites and satellite 2-1 is called aggregator satellite.

[0263] When the master satellite 4 is assured that the throughput Du required by the UE terminal is achieved thanks to the collaboration of the collector satellites 1-1 and 1-2 for the data collection part and thanks to the collaboration of the aggregator satellite 2-1 for the collection part and for the data aggregation part, the data collection can then begin.

[0264] Thus, during a step F6, the collector satellites 1-1, 1-2, the aggregator satellite 2-1 and the master satellite 4 capture the FSP subcarrier frequency identified in the collection request req-coll. The collector satellites 1-1, 1-2 then apply to the FSP subcarrier frequency, in a step F7, the functions of cyclic prefix insertion, beamforming, and IQ decompression.

[0265] In a step F8, the collector satellites 1-1 and 1-2 transmit data resulting from the processing of the FSP subcarrier frequency by the cyclic prefix insertion, beamforming, and IQ decompression functions, to the aggregator satellite 2-1.

[0266] The FSP subcarrier frequencies transmitted by the UE terminal and received by the collector satellites 1-1, 1-2 may have a phase shift due for example to jitter, or linked to the Doppler effect. In order to correct these effects, the collector satellites 1-1 and 1-2 use values ​​of a transmission delay between the UE terminal and each of the collector satellites 1-1 and 1-2 determined by means of control messages exchanged between the collector satellites 1-1 and 1-2 and the UE terminal in order to correct any offsets.

[0267] In a particular embodiment, the data collected by the collecting satellites 1-1 and 1-2 are stored in a cache memory of one of the functions of the physical and / or link layer prior to their processing by the latter. This makes it possible to limit the number of retransmissions requested from the UE terminal.

[0268] Upon receipt of this data collected and processed by the collecting satellites 1-1, 1-2, the aggregating satellite 2-1 applies to the data transmitted by the collecting satellites 1-1 and 1-2, the functions of mapping the resource elements, precoding, modulation and scrambling during a step F9.

[0269] The radio signal carrying the data processed by the collecting satellites 1-1, 1-2 may have a phase shift due for example to jitter, or linked to the Doppler effect. In order to correct these effects, the collecting satellites 1-1 and 1-2 use values ​​of a transmission delay between each of the collecting satellites 1-1 and 1-2 and the aggregating satellite 2-1 determined by means of control messages exchanged between the collecting satellites 1-1 and 1-2 and the aggregating satellite 2-1 in order to correct any offsets. In a particular embodiment, the data received by the aggregating satellite 2-1 are stored in a cache memory of one of the functions of the physical and / or link layer prior to their processing by the latter.

[0270] In a step F10, the aggregator satellite 2-1 transmits the data aggregated and processed by the resource element mapping, precoding, modulation and scrambling functions, to the master satellite 4.

[0271] Upon receipt of this data collected and processed by the aggregator satellite 2-1, the master satellite 4 proceeds to aggregate it with the data that it has itself collected and processed, in a Fil step.

[0272] Finally, in a step F12, the master satellite 4 transmits the data thus approved to the equipment 5. The equipment 5 applies to this aggregated data functions of the level 2 layers such as the RLC (Radio Link Control) and MAC (Medium Access Control) layers before transmitting them to the GW equipment of the CORE network in a step F13.

[0273] [Fig. 4] represents a diagram of the different stages of the methods of transmission of collection, aggregation and processing of the data transported by at least one subcarrier frequency allocated to the terminal implemented by the different equipment constituting the RAN access network in a third embodiment of the invention.

[0274] Just as in the first and second embodiments, in the implementation example described below, satellite 4, called master satellite, is the satellite serving cell 2. In other words, a terminal UE located in cell 2 wishing to establish communication with another terminal (not shown in the figures) attaches to the radio access network RAN ​​by establishing a radio link with a gNB access node of the radio access network RAN. As described with reference to FIG. 1, master satellite 4 carries a RU unit and / or a DU unit constituting the gNB access node.

[0275] In this third embodiment, in addition to the satellite 2-1 called the aggregator satellite, at least one satellite, called the processing satellite, participates in the collection of the data transmitted by the terminal UE. The intervention of such a processing satellite in the collection is of interest, for example, when certain collector and aggregator satellites are unable to implement a given split or partial split.

[0276] Thus, during a first step Gl, the master satellite 4 obtains information relating, among other things, to a value of the transmission power of the UE terminal, to the radio environment in which the UE terminal is located, to a value of the variance of the “shadowing” impacting the UE terminal or even and values ​​of characteristics such as the reception gain of the satellites 1-1 to 1-3, 2-1, 2-2 and 3-1 and 3-3. Optionally, the information provided to the master satellite 4 may indicate an optimization of at least one antenna of the UE terminal, such as for example an identifier of a cardinal sector of the antenna of the UE terminal to be favored in transmission, in order to increase the value of the power received by a satellite picking up the radio signal transmitted by the user terminal.

[0277] Finally, the information provided to the master satellite 4 further comprises an identifier of at least one FSP subcarrier frequency allocated to the terminal for communicating with the master satellite and at least one index of a modulation and coding table used by the UE terminal to modulate and code the FSP subcarrier frequency, as well as the type of modulation applied such as for example QAM (Quadrature Amplitude Modulation in English) or QPSK (Quadrature Phase-Shift Keying in English).

[0278] When the reception quality of the radio signals transmitted by the UE terminal is not satisfactory, the master satellite 4 generates, in a step G2, a collection request req-coll. Such a collection request req-coll includes, among other things:

[0279] • information relating to the duration of the collection,

[0280] • a start time and an end time for the collection,

[0281] • information relating to a roaming policy negotiated between the radio access network operator and an operator of another radio access network to which the terminal may be required to attach itself,

[0282] • an identifier of one or more FSPj subcarrier frequencies that satellites agreeing to collaborate can capture,

[0283] • an identifier of at least one index of a modulation and coding table (Modulation and Coding Scheme in English), and

[0284] • a type of modulation applied by the UE terminal to the FSP subcarrier frequency intended to be transmitted: NR QPSK, 16 QAM, 64 QAM, 256 QAM, etc.

[0285] Once the collection request req-coll has been generated, the master satellite 4 searches for at least one other satellite capable of capturing the subcarrier frequency FSP, identified in the collection request req-coll, transmitted by the terminal UE, at least one other satellite capable of aggregating the data collected by the collector satellites and at least one other satellite capable of processing the data aggregated by the aggregator satellite, prior to their transmission to the master satellite 4. The master satellite 4 can carry out such a search while another satellite belonging to the constellation const-4, to which the master satellite 4 also belongs, is in position to be able to serve the cell-2 in which the user terminal is located.

[0286] To this end, the master satellite 4 broadcasts the collection request req-coll during a step G3.

[0287] In order to ensure that the data collected then aggregated and processed by the satellites give a favorable response to the collection request req-coll, the latter specifies for each type of satellite, collector, aggregator or processing, the function(s) of the physical and / or link layer, for example, which must be applied to the FSP subcarrier frequency by each of them before their transmission. Thus, the master satellite 4 is assured of receiving only data processed in accordance with its needs independently of the splits implemented within the collector satellites 1-1, 1-2, aggregator 2-1 and processing satellites.

[0288] The fact that the master satellite 4 explicitly announces the function(s) of the physical and / or link layer to be applied to the FSP subcarrier frequency by the collector satellites 1-1 and 1-2, then the function(s) of the physical and / or link layer to be applied to the FSP subcarrier frequency by the aggregator satellite, and finally the function(s) of the physical and / or link layer to be applied to the FSP subcarrier frequency by the processing satellite, makes it possible for the satellites responding favorably to the req-coll collection request to transmit incomplete or erroneous data from the point of view of the eCPRI protocol, since they may not have had all the functions constituting the split implemented in such a satellite applied to them.

[0289] Thus, by way of example, the collection request req-coll broadcast by the master satellite 4 during step G3 indicates that the master satellite 4 wishes to receive data having been processed, at the level of a collector satellite 1-1, 1-2 by a decompression function IQ, then having been processed, hereinafter partial split 1, at the level of the aggregator satellite, by a modulation function, hereinafter partial split 2, and at the level of the processing satellite, by a scrambling function, hereinafter partial split 3.

[0290] In a step G4, the different satellites 1-1 to 1-3, 2-1, 2-2, 3-1 to 3-3 - intercept the collection request req-coll.

[0291] In a step G5 which may be consecutive to step G4 or prior to step G1, satellites 1-1 to 1-3, 2-1, 2-2 and 3-1 to 3-3 broadcast information relating to their availability such as for example a value of the charge of their battery, their flight plan, a list of subcarrier frequencies FSPj which they can receive, etc. More particularly, satellites 2-1, 2-2 and 3-1 to 3-3 announce which splits or partial splits they support. Thus, the master satellite 4 has the information allowing it to know which satellite 2-1, 2-2 and 3-1 to 3-3 supports partial splits 1, 2 and 3. In the example chosen, satellites 1-1, 1-2, 2-1 and 3-1 respectively support partial split 1, partial split 2 and partial split 3 can therefore meet the needs of the master satellite 4. Satellites 1-1 and 1-2 are then called collector satellites, satellite 2-1 is called aggregator satellite and satellite 3-1 is called processing satellite.

[0292] When the master satellite 4 is assured that the throughput Du required by the terminal UE is achieved thanks to the collaboration of the collector satellites 1-1 and 1-2 for the data collection part and thanks to the collaboration of the aggregator satellite 2-1 for the collection part and for the data aggregation part and by the processing satellite 3-1 for the collection part and for the processing part, the data collection can then begin. Thus, during a step G6, the collector satellites 1-1, 1-2, the aggregator satellite 2-1, the processing satellite 3-1 and the master satellite 4 capture the FSP subcarrier frequency identified in the collection request req-coll. The collector satellites 1-1, 1-2 then apply to the FSP subcarrier frequency, in a step G7, the functions of insertion of the cyclic prefix, of beamforming, and of IQ decompression.

[0293] In a step G8, the collector satellites 1-1 and 1-2 transmit data resulting from the processing of the FSP subcarrier frequency by the cyclic prefix insertion, beamforming, and IQ decompression functions, to the aggregator satellite 2-1.

[0294] The FSP subcarrier frequencies transmitted by the UE terminal and received by the collector satellites 1-1, 1-2 may have a phase shift due for example to jitter, or linked to the Doppler effect. In order to correct these effects, the collector satellites 1-1 and 1-2 use values ​​of a transmission delay between the UE terminal and each of the collector satellites 1-1 and 1-2 determined by means of control messages exchanged between the collector satellites 1-1 and 1-2 and the UE terminal in order to correct any offsets.

[0295] In a particular embodiment, the data collected by the collecting satellites 1-1 and 1-2 are stored in a cache memory of one of the functions of the physical and / or link layer prior to their processing by the latter. This makes it possible to limit the number of retransmissions requested from the UE terminal.

[0296] Upon receipt of this data collected and processed by the collecting satellites 1-1, 1-2, the aggregating satellite 2-1 applies to the data transmitted by the collecting satellites 1-1 and 1-2, the functions of mapping the resource elements, precoding, and modulation during a step G9.

[0297] The radio signal carrying the data processed by the collecting satellites 1-1, 1-2 may also have a phase shift due for example to jitter, or linked to the Doppler effect. In order to correct these effects, the collecting satellites 1-1 and 1-2 use values ​​of a transmission delay between each of the collecting satellites 1-1 and 1-2 and the aggregating satellite 2-1 determined by means of control messages exchanged between the collecting satellites 1-1 and 1-2 and the aggregating satellite 2-1 in order to correct any offsets.

[0298] In a particular embodiment, the data received by the aggregator satellite 2-1 are stored in a cache memory of one of the functions of the physical and / or link layer prior to their processing by the latter.

[0299] In a step G10, the aggregator satellite 2-1 transmits the data aggregated and processed by the resource element mapping, precoding, and modulation functions, to the processing satellite 3-1. Upon receipt of this data collected and processed by the aggregator satellite 2-1, the processing satellite 3-1 proceeds to aggregate it with the data that it has itself collected and processed, in a step G11.

[0300] Then, in a step G12, the processing satellite 3-ltransmits the data aggregated and processed by the modulation function, to the master satellite 4.

[0301] Upon receipt of this data collected and processed by the processing satellite 3-1, the master satellite 4 proceeds to aggregate it with the data that it has itself collected and processed, in a step G13.

[0302] Finally, in a step G14, the master satellite 4 transmits the data thus approved to the equipment 5. The equipment 5 applies to this aggregated data functions of the level 2 layers such as the RLC (Radio Link Control) and MAC (Medium Access Control) layers before transmitting them to the GW equipment of the CORE network in a step G15.

[0303] [Fig. 5] represents a satellite 1-1 to 1-3, 2-1, 2-2, 3-1 to 3-3 and 4 capable of implementing all or part of the methods of transmission, collection, aggregation and processing of data transported by at least one subcarrier frequency allocated to the terminal which is the subject of the invention.

[0304] The satellite 1-1 to 1-3, 2-1, 2-2, 3-1 to 3-3 and 4 may comprise at least one hardware processor 10, a storage unit 11, at least one antenna 12, and a network interface 13 which are connected to each other through a bus 14. Of course, the constituent elements of the satellite 1-1 to 1-3, 2-1, 2-2, 3-

[0305] I to 3-3 and 4 can be connected using a connection other than a bus.

[0306] The processor 10 controls the operations of the satellite 1-1 to 1-3, 2-1, 2-2, 3-1 to 3-3 and 4. The storage unit 11 stores at least one program for collecting, aggregating and / or processing data carried by at least one subcarrier frequency allocated to a terminal UE to be executed by the processor 10, and various data, such as parameters used for calculations performed by the processor 10, intermediate data of calculations performed by the processor 10, etc. The processor 10 may be formed by any known and suitable hardware or software, or by a combination of hardware and software. For example, the processor 10 may be formed by dedicated hardware such as a processing circuit, or by a programmable processing unit such as a central processing unit (Central Processing Unit) which executes a program stored in a memory thereof.

[0307] The storage unit 11 may be formed by any suitable means capable of storing the program, data in a computer-readable manner. Examples of storage unit

[0308] They include non-transitory computer-readable storage media such as semiconductor memory devices, and magnetic, optical, or magneto-optical recording media loaded into a read-write unit. The program causes the processor 10 to execute a method for managing the retransmission of missing data according to one embodiment of the invention.

[0309] The antennas 12 provide an interface between the satellite 1-1 to 1-3, 2-1, 2-2, 3-1 to 3-3 and 4 and the terminal UE or other satellites 1-1 to 1-3, 2-1, 2-2, 3-1 to 3-3 and 4. A network interface 13 provides a connection between the satellite 1-1 to 1-3, 2-1, 2-2, 3-1 to 3-3 and 4 and the equipment 5.

Claims

CLAIMS 1. Method for transmitting data to at least one piece of equipment belonging to a communications network, said method comprising the following steps implemented by a first satellite, called the master satellite (4): - broadcasting, to at least one second satellite, called the collecting satellite (1-1, 1-2), a request to collect data transported by at least one subcarrier frequency, - collection of data transported by said at least one subcarrier frequency, - aggregation of said collected data and data transmitted by said collecting satellite (1-1, 1-2), - transmission of aggregated data to said at least one device belonging to a communications network.

2. Data transmission method according to claim 1 wherein said at least one subcarrier frequency is allocated to at least one terminal located in a cell of a radio communication network served at least by said master satellite (4).

3. A method of transmitting data according to claim 1 wherein said collection request comprises parameters relating to said cell of said radio communication network.

4. Data transmission method according to any one of claims 1 to 3 where said collection request comprises at least one identifier of at least one first function of said at least one collecting satellite (1-1, 1-2) intended to be applied to the data collected prior to their transmission to the master satellite (4).

5. Transmission method according to any one of claims 1 to 4 in which the collection request comprises: - information relating to the modulation and coding scheme of a radio signal intended to modulate said at least one subcarrier frequency, - information relating to the type of modulation to be applied to said at least one subcarrier frequency.

6. Transmission method according to any one of claims 1 to 5 wherein the collection request comprises an identifier of said at least one collecting satellite (1-1, 1-2).

7. Transmission method according to any one of claims 1 to 6 in which the collection request comprises: - an identifier of at least one third satellite, called an aggregator satellite (2-1), configured to collect and aggregate said data transmitted by said at least one collector satellite (1-1, 1-2).

8. Transmission method according to claim 7 wherein the collection request comprises: - at least one identifier of at least one second function of said at least one aggregator satellite (2-1) intended to be applied to aggregated data prior to their transmission to the master satellite (4).

9. Transmission method according to claim 7 or 8 in which the collection request comprises: - an identifier of at least one fourth satellite, called processing satellite, configured to process said aggregated data transmitted by said at least one aggregator satellite (2-1).

10. A transmission method according to claim 9 wherein the collection request further comprises: - at least one identifier of at least one third function of said at least one processing satellite intended to be applied to the data received prior to their transmission to the master satellite (4).

11. Method for collecting data, said method comprising the following steps implemented by a second satellite, called the collecting satellite (1-1, 1-2): - reception, from at least one first satellite, called master satellite (4), of a request to collect data transported by at least one subcarrier frequency, - collection of data transported by said at least one subcarrier frequency, - processing by applying at least a first function of said collecting satellite (1-1, 1-2) to said collected data, - transmission of processed data to the master satellite (4).

12. Data collection method according to claim 11 wherein said at least one subcarrier frequency is allocated to at least one terminal located in a cell of a radio communication network served at least by said master satellite (4).

13. A method of collecting data according to claim 11 or 12 wherein said collection request comprises parameters relating to said cell of the radio communication network.

14. Data collection method according to any one of claims 9 to 13 wherein said collection request comprises at least one identifier of said first function of said collecting satellite (1-1, 1-2).

15. Method for aggregating data, said method comprising the following steps implemented by a second satellite, called aggregator satellite (2-1): - reception, from at least one first satellite, called the master satellite, of a request to collect data transported by at least one subcarrier frequency, - collection of data transmitted by at least a third satellite, called a collector satellite (1-1, 1-2), - aggregation of said data collected by said at least one collecting satellite (1-1, 1-2) - processing by applying at least one second function of said aggregator satellite (2-1) to said aggregated data, - transmission of processed data to the master satellite (4).

16. Data aggregation method according to claim 15 wherein said at least one subcarrier frequency is allocated to at least one terminal located in a cell of a radio communication network served at least by said master satellite (4).

17. A method of aggregating data according to claim 15 or 16 wherein said collection request comprises parameters relating to said cell of the radio communication network.

18. Data aggregation method according to any one of claims 15 to 17 wherein said collection request comprises at least one identifier of said second function of said aggregator satellite (2-1).

19. Data processing method, said method comprising the following steps implemented by a second satellite, called processing satellite (3-1): - reception, from at least one first satellite, called master satellite (4), of a request to collect data transported by at least one subcarrier frequency, - collection of data transmitted by at least a third satellite, called an aggregator satellite (2-1), - processing by applying at least one third function of said processing satellite (3-1) to said collected data, - transmission of processed data to the master satellite (4).

20. Data processing method according to claim 19 wherein said at least one subcarrier frequency is allocated to at least one terminal located in a cell of a radio communication network served at least by said master satellite (4).

21. Data processing method according to claim 19 or 20 wherein said collection request comprises parameters relating to said cell of the radio communication network.

22. Data processing method according to any one of claims 19 to 21 wherein said collection request comprises at least one identifier of said third function of said processing satellite (3-1).

23. Communication satellite, called master satellite (4), capable of transmitting data to at least one piece of equipment belonging to a communication network, said master satellite (4) comprising at least one processor configured to: - broadcast, to at least one second satellite, called a collector satellite (1-1, 1-2), a request to collect data transported by at least one subcarrier frequency, - collect data transported by said at least one subcarrier frequency, - aggregate said collected data and data transmitted by said collecting satellite (1-1, 1-2), - transmit the aggregated data to said at least one device belonging to a communications network.

24. Communication satellite, called collecting satellite (1-1, 1-2), capable of collecting data, said collecting satellite (1-1, 1-2) comprising at least one processor configured to: - receive, from at least one first satellite, called the master satellite (4), a request to collect data transported by at least one subcarrier frequency, - collect data transported by said at least one subcarrier frequency, - processing by applying at least a first function of said collecting satellite (1-1, 1-2) to said collected data, - transmit processed data to the master satellite (4).

25. Communication satellite, called aggregator satellite (2-1), capable of aggregating data, said aggregator satellite (2-1) comprising at least one processor configured to: - receive, from at least one first satellite, called the master satellite (4), a request to collect data transported by at least one subcarrier frequency, - collect data transmitted by at least a third satellite, called a collector satellite (1-1, 1-2), - aggregate said data collected by said at least one collecting satellite (1-1, 1-2) - processing by applying at least a second function of said aggregator satellite (2-1) to said aggregated data, - transmit processed data to the master satellite (4).

26. Communication satellite, called processing satellite (3-1), capable of processing data, said processing satellite (3-1) comprising at least one processor configured to: - receive, from at least one first satellite, called the master satellite, a request to collect data transported by said at least one subcarrier frequency, - collect data transmitted by at least a third satellite, called an aggregator satellite (2-1), - processing by applying at least a third function of said processing satellite (3-1) to said collected data, - transmit processed data to the master satellite (4).

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