Method for monitoring a quality-of-service level between a user device and an access device for accessing a communication network, and corresponding apparatus, access device, communication system and computer program

Abstract

The invention relates to a method for monitoring a quality-of-service level of a communication between a user device and a first wireless communication network, the method comprising: determining (31) a value of a parameter representative of the quality-of-service level of the communication between an access device, referred to as a server device, of the first network to which the user device is attached and the user device (UE), the communication using a given frequency band, the value being determined at least according to: a bandwidth allocated to said communication; transmission characteristics of the server access device; at least one other access device of the first network and at least one other access device of at least a second wireless communication network, which are configured to use the given frequency band and are capable of interfering with communication; and a topology of the first network and of the at least one second network in at least one zone, referred to as an interference zone; when the determined value does not reach a target value of the parameter, obtaining a modification (34) of at least one transmission characteristic of the server access device and / or of at least one other access device of the first and / or of the at least one second network according to a difference between the determined value and the target value.

Description

[0001] DESCRIPTION TITLE: Method for controlling a level of quality of service between user equipment and access equipment to a communication network, corresponding device, access equipment, communication system and computer program. Technical field of the invention The present invention belongs to the general field of telecommunications. It relates more particularly to the coexistence of several wireless communication networks using the same resources in a given geographical area. The invention finds a preferred but non-limiting application in the context of mobile services based on such communication networks. Prior art Today, there are several types of networks allowing a user to access mobile communication services, such as for example a terrestrial cellular network, a satellite network, a network of remotely controlled devices or drones,or a network of high altitude platforms or HPA (in English, "High Altitude Platforms"). These networks of different types can be managed by the same operator or by separate operators. However, the frequency spectrum is a rare commodity, and given the growing number of networks and the plurality of operators, we can expect that the same frequency band will be allocated to several heterogeneous networks, for example to a terrestrial cellular network and a satellite network managed by the same operator (or by separate operators). In this context, communications established within these networks with user equipment located in the same geographical area and relying on the same resources will create interference on each other, which will have an impact on the quality of these communications, and therefore on the experience of users of the user equipment. In the current state of the art,it is known to take into account in the context of a cellular network, for example compliant with the third generation of the 3GPP standard (3G), intra-cellular and / or inter-cellular interference linked to the use of the same resources (and in particular the same frequency band) on a user's communication. In a satellite context, the document by N. Gupta and S. Bitragunta, entitled "Green Satellite Communication Link Design, Optimization and Performance Analysis", IEEE 7th Uttar Pradesh Section International Conference on Electrical, Electronics and Computer Engineering (UPCON), 2020, pages 1-5, focuses on the performance of a satellite network in terms of energy efficiency,this being defined from the power of the thermal noise. This document mentions the possibility of taking interference into account in the calculation of this energy efficiency in the case of sharing of the frequency spectrum but no indication is given on the nature of the interference in question or on how to do it. In any case, none of these approaches is interested in the coexistence of several networks of distinct types (e.g. satellite network, terrestrial cellular network,etc.) in the same geographical area (also referred to as "heterogeneous networks" in the following) and does not allow a network operator to ensure the performance of its network in the event of simultaneous use of the same resources by different access equipment belonging to networks of distinct types. In particular, none of these approaches allows a network operator to ensure that in such a context it is able to provide a given quality of service to a user equipment. The invention improves the situation. Presentation of the invention The invention meets this need by proposing a method for controlling a level of quality of service of a communication between a user equipment and a first wireless communication network,said method comprising: - determining a value of a parameter representative of the level of quality of service of the communication between an access device called server device of the first network to which said user device is attached and said user device, said communication using a given frequency band, said value being determined at least as a function of a bandwidth allocated to this communication, of transmission characteristics of the server device, of at least one other access device of the first network and of at least one other access device of at least one second wireless communication network, said at least one other access device of the first network and said at least one other access device of said at least one second network being configured to use said given frequency band and being likely to interfere with the communication,and a topology of the first network and of the at least one second network in at least one so-called interference zone; - when the determined value does not reach a target value of said parameter, obtaining a modification of at least one transmission characteristic of said server access equipment and / or of at least one other access equipment of the first and / or of the at least one second network, as a function of the target value. For example, said value of the parameter is determined at least as a function of the bandwidth allocated to the communication, a distance between the user equipment and the server equipment, a transmission power of the server equipment, antenna gain ratios between the server equipment and said at least one other access equipment of the first network and between the server equipment and said at least one other access equipment of the at least one second network,and the topology of the first network and of the at least one second network in said at least one interference zone. The invention applies in a preferred manner to communication in the downlink direction, i.e. from the server equipment to the user equipment. It also applies in a preferred manner when the first and second networks are distinct and heterogeneous networks in the sense that they rely on different technologies and comprise access equipment of different types. For example, the first network comprises terrestrial base stations and the second network access equipment located in the air or in space such as satellites. Of course, the invention is not limited to this example of a second satellite network and applies to other types of network,such as for example a drone network and a high-altitude platform network. For the sake of simplification, we hereinafter refer to such a network as an "aerial" type network (i.e. relying on access equipment located in the air such as drones or high-altitude platforms or on access equipment located in space such as satellites). It is further assumed that the user equipment can be attached to any type of access equipment, belonging to any of the previously mentioned terrestrial or aerial communications networks. No limitation is attached to the nature of the user equipment. It can be any receiving device, such as for example a fixed or mobile client terminal of the first network (e.g. a smartphone, a computer, etc.). In the case where the server equipment is a satellite of a satellite network,the user equipment may also be a terrestrial radio transmitting / receiving station of this satellite network. The invention is based on a completely new and inventive approach to controlling a level of quality of service on the downlink radio link between a user equipment and the server access equipment which connects it to a first communication network in the presence of interference generated by other networks. It consists in determining the effective value of a quality of service parameter as perceived at the user equipment, taking into account the influence on the performance of the communication not only of the transmission characteristics of the server equipment (e.g. transmission power, distance from the user equipment), but also of those of other interfering access equipment of the first network and of at least one second network,but also the topology of each of these networks in an interference zone. Typically, such a topology may include a density of access equipment of the first and second networks likely to interfere with communication in an interference zone, an average distance between the access equipment, an altitude of the access equipment, a minimum elevation angle or any other characteristic making it possible to define an area of ​​interference with the communication. This topology in the interference zone is used by the invention to model in a very simple way the interference generated on the communication between the server access equipment and the user equipment by the other access equipment simultaneously using the same resources (and more particularly here the same frequency band) as the server access equipment during its communication with the user equipment. More specifically,the invention does not attempt to tediously determine the individual contribution of each access device interfering with the communication, then to sum the individual contributions of these access devices, but considers the impact of these other access devices on the communication as a whole thanks to knowledge of the topology of the networks to which they belong. When the actual value obtained does not reach a given target value, for example required by an application running on the user equipment,a modification to be made to the value of one or more transmission characteristics of one or more access devices of the first network and / or the second network is determined so as to achieve this target value. The invention therefore makes it possible to configure the server equipment of the user equipment and / or one or more access devices of one or more networks of different types which interfere with the communication between the server equipment and the user equipment to enable it to achieve the target value. The modification of the at least one transmission characteristic can therefore apply to the server access equipment and / or to the other access devices of the first network and / or to access devices of the second network. Thus,the invention can be used upstream of a communication: it then allows the operator of the first network to know a priori whether a server access equipment meets a quality of service requested by a user equipment. If it is not possible to determine a modification of the transmission characteristics of the server access equipment verifying this quality of service, the operator can advantageously anticipate a failure of the communication and envisage upstream of the communication different actions aimed at improving the user experience: informing the user, rejecting the communication, selecting another access equipment to serve the communication, etc. Alternatively, it can also modify the transmission characteristics of other interfering access equipment of the first network or those of interfering access equipment of the second network,in particular if he is himself the operator. If the second network is operated by another operator, inter-operator agreements can be put in place for this purpose. But the invention can also be used during communication to dynamically adapt the values ​​of one or more transmission characteristics of this communication, such as the transmission power of the server access equipment, the bandwidth allocated to the communication or the communication rate. The invention can also be implemented in a tool for planning the deployment of terrestrial or aerial access equipment (including drones, high-altitude platforms and / or satellites). According to one aspect of the invention,the first network and the second network are networks of distinct types belonging to a group comprising at least one terrestrial type network comprising a plurality of terrestrial base stations and a so-called aerial type network comprising a plurality of aerial or space access equipment, and the determination of a value of a parameter representative of the level of quality of service of the communication comprises the determination of a first impact factor on the value of said parameter of the other access equipment of the first network interfering with the communication and the determination of a second impact factor on the value of said parameter of the access equipment of the second network interfering with the communication. An aerial type network designates both a satellite communication network whose access equipment is satellites, for example satellites placed in orbit around the Earth at approximately 600 km from the ground,than a communication network of drones located a few hundred meters above the ground or a communication network of high-altitude platforms located approximately 80 km above the ground. According to the invention, the server equipment can therefore be a terrestrial base station, a satellite, a drone, a high-altitude platform, etc. An advantage of the invention is to determine in a global manner, on the one hand, the impact of the other access equipment of the first network and, on the other hand, that of the access equipment of the second network on the communication between the server equipment and the user equipment. According to another aspect of the invention, the first network being a terrestrial type network and the server equipment a terrestrial base station, the determination of the first impact factor, called terrestrial impact factor, is a function of a density of other terrestrial base stations of the first network, called interfering base stations,located in a terrestrial interference zone defined at least as a function of an average distance between the base stations of the first network. The invention thus proposes to define a terrestrial interference zone as a function of the topology of the first network and to determine the overall impact of the other interfering terrestrial base stations on the quality of service of the downlink radio link between the serving base station rather than summing the individual impacts of each of them. An advantage is that it is not necessary to know the absolute positions of each of the other base stations relative to the user equipment. The technique of the invention is therefore relatively uncomplicated.,

[0002] According to yet another aspect of the invention, the serving base station comprising a first, a second and a third antenna covering three sectors, the determination of the terrestrial impact factor noted Fb comprises the implementation of a relationship equivalent to the following relationship: where ISD denotes the average distance between the serving base station and the interfering base stations, ρ B denotes the density of base stations in the terrestrial interference zone, δ denotes the fading factor (from the English, “path-loss”) modeling the propagation attenuation, r the radius or distance between the user equipment and the first antenna, h the height of the first antenna relative to the user equipment,

[0003] (r, θ, φ ) denotes the spherical coordinates of the user equipment in a reference frame O1'xyz centered on the serving base station at ground level, θ the elevation angle between the user equipment and said first antenna,

[0004] Φ the horizontal angle between the user equipment and said first antenna,

[0005] A(θ, φ ) is the angular gain of the first antenna of the serving base station, to which the user equipment UE is connected;

[0006] A(θ k , φk ) the angular gain of each of the other two antennas (k=2, 3) of the serving base station, co-located with the first antenna of the serving base station.

[0007] H1 is the gain of each antenna of the first RT network, defined as follows by: H1(θ) dB = — min[— H(θ) dB , HAS m + V 1,dB ], where Am denotes the minimum antenna gain, and is a constant,

[0008] , where φ tilt is the downward tilt angle, φ 3dB the width of the half-power vertical beam, θ 3dB the half-power horizontal beamwidth, and a contribution from the other two antennas of the serving base station uses a relationship equivalent to the following relationship: where k = 2.3 the other two antennas of the serving base station. According to another aspect of the invention, the second network being an aerial type network comprising a plurality of satellites placed in orbit around the Earth, the determination of the second impact factor, called satellite impact factor, is a function of a density of satellites interfering with the communication in a satellite interference zone defined at least as a function of an altitude of the satellites of the second network and a minimum elevation angle of said satellite with said user equipment.According to this embodiment, the invention relies on the fact that the satellites present in the satellite interference zone cover a geographical area intersecting in whole or in part the geographical coverage area of ​​the server equipment (in which the user equipment is located) and are therefore likely to generate overall interference at the user equipment level which depends on the density of the satellites using the same resources as the server access equipment in this area. It is noted that if one wishes to maximize the level of quality of service in the second (satellite) network and in particular the throughput offered by this network, it is appropriate to maximize the use of the resources: this results in the satellites using all of their resources.In such a configuration, all the satellites located in the satellite interference zone are likely to interfere with the communication of the server access equipment with the user equipment because the probability that these satellites simultaneously use the same resources as the communication tends towards 1. The density of satellites likely to interfere with the communication located in the satellite interference zone is therefore equal or substantially equal to the density of the satellites of the system located in the satellite interference zone. If, however, the assumption of the use of all the resources by the satellites of the satellite network does not apply, it is appropriate to consider the density of satellites located in the satellite interference zone and simultaneously using the same resources as the communication in question.According to this embodiment, the impact factor of the satellites of the second network on the communication is defined as the product of the density of the satellites and the integral of the power received by the user equipment from the satellites of the second network likely to interfere with the communication located in the satellite interference zone. According to another embodiment, other types of aerial access equipment, for example drones, are present near the user equipment (in addition to the satellites mentioned above or as a replacement), use the same frequency band and are therefore likely to interfere with the communication between the user equipment and the server equipment of the first network.Advantageously, the determination of a value of a parameter representative of the level of quality of service of the communication then further takes into account a transmission power and antenna gain ratios of drones of this third network and comprises the determination of a third impact factor (Fd), called the drone impact factor, said drone impact factor being a function of a density of interfering drones in a drone interference zone. A similar reasoning can be applied with aerial access equipment of the HPA type with the determination of an impact factor of the HPAs.

[0009] According to yet another aspect of the invention, when the second network is a satellite network, determining a quality of service parameter value further comprises determining a number of interfering satellites for said communication in the satellite interference zone and the density of interfering satellites in the satellite interference zone is determined as a function of the number of interfering satellites and a surface area of ​​a spherical cap centered on the user equipment, of radius the orbit of the satellites of the satellite network, and delimited by taking into account said minimum elevation angle.

[0010] In a particular embodiment of the invention, the determination of the satellite impact factor comprises the implementation of a relationship equivalent to the following equation:

[0011] Where ρ SATdenotes the density of interfering satellites (i.e. located in the satellite interference zone),

[0012] R T denotes the radius of the Earth, h SAT the altitude of the interfering satellites in a reference frame centered on the user equipment, α denotes the minimum elevation angle and d M means the distance between the user equipment and the satellite located at the minimum elevation angle.

[0013] An advantage is that, via geometric considerations, the invention allows, from this integration on the satellite interference zone, defined as a spherical cap centered on the user equipment, of radius the orbit of the satellites of the satellite network, and delimited by taking into account a minimum elevation angle of the satellites to be likely to interfere with the communication, to obtain a very simple expression of the satellite impact factor.

[0014] According to another aspect of the invention, the determination of a value of a parameter representative of the level of quality of service of the communication further comprises the determination of a transmission power by the serving base station as a function of the terrestrial impact factor and of the at least one second impact factor associated with said at least one second network, implementing a relationship equivalent to the following relationship: where I is an integer greater than or equal to two, designating a number of said second networks (of the aerial type) comprising access equipment likely to interfere with said communication,

[0015] Fb is the terrestrial impact factor,

[0016] F i the impact factor of a so-called second network,

[0017] P i the transmission power of each access equipment interferes with a so-called second network,

[0018] G i: the gain of each access equipment interfering with a so-called second network,

[0019] K i a propagation constant of each access equipment interfering with a said second network,

[0020] G b : the gain of terrestrial base stations,

[0021] N th thermal noise,. with D u the useful data reception rate by the user equipment on the downstream radio link, and

[0022] W is the bandwidth used by communication on the downlink radio link between the serving base station and the user equipment.

[0023] An advantage of this embodiment of the invention is that it allows, via geometric considerations, to obtain a very simple expression based on an integral of the power received from the other interfering base stations of the first network and from the other interfering access equipment of the other networks (of the aerial type), which depends only on the impact factors, the antenna gains and the transmission powers of the access equipment of the first and second networks.

[0024] According to another embodiment of the invention, the quality of service parameter belongs to a group comprising at least:

[0025] - a useful data reception rate by the user equipment;

[0026] - a useful delay in transmitting data to the user equipment;

[0027] - a useful power for receiving data by the user equipment.

[0028] According to a particular embodiment, the quality of service parameter comprises a useful data transmission rate and the useful rate (315) is derived from the expression of the transmission power by the serving base station and determined according to the following equation:

[0029] An advantage is that the actual value of the useful flow rate is obtained relatively simply.

[0030] According to another embodiment of the invention, the quality of service parameter comprises a useful delay Del u data transmission which is derived from the determined transmission power, by implementing a relationship equivalent to the following relationship: where V denotes a volume of data transmitted.

[0031] According to another aspect of the invention, the control method according to the invention comprises the determination of a third impact factor associated with other interfering access equipment of a third communication network, of the drone type, as a function of a density (ρ d ) of drones interfering with communication in a drone interference zone (CSd) defined at least as a function of an altitude of the drones of the third network and a minimum elevation angle of said drone with the user equipment and in that said determination (315) implements the following equation: where Fd is the impact factor of drones from the third network on the communication between the serving base station and the user equipment, ρ d is the density of interfering drones,

[0032] P d the transmission power of said drone interferes,

[0033] G d : the gain of said drone interferes, and

[0034] K d a constant in the spread of drones.

[0035] This makes it possible to take into account in a relatively simple way the impact of the access equipment of the different networks present near the user equipment.

[0036] According to another aspect of the invention, said at least one modified emission characteristic belongs to a group comprising at least:

[0037] - a transmission power of at least one antenna of the server equipment;

[0038] - a gain of said at least one antenna;

[0039] - a transmission bandwidth of said at least one antenna, - a transmission power of at least one antenna of at least one other interfering access equipment, - a gain of said at least one antenna of at least one other interfering access equipment; - a transmission bandwidth of said at least one antenna of at least one other interfering access equipment. An advantage is that it is possible to act on the antenna(s) of the server access equipment and / or on those of the interfering access equipment, of the first network or of another network present in the geographical area in which the user equipment is located. The invention also relates to a device for controlling a level of quality of service of a communication between a user equipment and a first wireless communication network, said first network comprising a plurality of access equipment configured to transmit radio frequency beams in a given frequency band. Saiddevice is configured to implement: - the determination of a value of a parameter representative of the level of quality of service of the communication between a first access equipment of said plurality, to which said user equipment is attached, called server access equipment, at least as a function of a bandwidth allocated to this communication, of transmission characteristics of the server access equipment, of at least one other access equipment of the first network and of at least one other access equipment of at least one second wireless communication network, said other access equipment of the first network and of the at least one second network being configured to emit radio frequency beams in the given frequency band and being likely to interfere with the communication, and of a topology of the first network and of the at least one second network in at least one so-called interference zone; - when the determined value does not reacha target value of said parameter, determining a modification of at least one transmission characteristic of at least one antenna of said server access equipment and / or of at least one other access equipment of the plurality and / or of the at least one second network, as a function of the target value. For example, said value of the parameter is determined at least as a function of the bandwidth allocated to this communication, a distance between the user equipment and the server access equipment, a transmission power of the server access equipment, antenna gain ratios of the server access equipment, of said at least one other access equipment of the first network and of said at least one other access equipment of the at least one second network, and of the topology of the first network and of the at least one second network in said at least one interference zone. Advantageously, said control device is integrated in the server equipment of the first network ofcommunication. Alternatively, it may be integrated into other access equipment of the first communications network or into the user equipment. In one embodiment, said control device is integrated into a communication system, comprising access equipment of the first network, including the server equipment of the user equipment and access equipment of at least one second network, said access equipment being configured to emit radio frequency beams in a given frequency band, said system further comprising the user equipment and the aforementioned control device. The communication system and the control device have at least the same advantages as those conferred by the aforementioned control method. The invention also relates to a computer program product comprising program code instructions for the respective implementation of the aforementioned control method, when executed bya processor. A program may use any programming language, and 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. The invention also relates to at least one computer-readable recording medium on which is recorded a computer program comprising program code instructions for executing the steps of the method according to the invention as described above. Such a recording medium may be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording means, for example a mobile medium (memory card) or a hard disk or an SSD. Furthermore, such a recording medium may be atransmissible medium such as an electrical or optical signal, which can be conveyed via an electrical or optical cable, by radio or by other means, so that the computer program it contains is remotely executable. The programs according to the invention can in particular be downloaded over a network, for example the Internet. Alternatively, the recording medium(s) may be one or more integrated circuits in which each program is incorporated, the circuit(s) being adapted to execute or to be used in the execution of the aforementioned method. According to an exemplary embodiment, the present technique is implemented by means of software and / or hardware components. With this in mind, the term "module" can correspond in this document to a software component, a hardware component or a set of hardware and software components. A software component corresponds to one or more computer programs, one orseveral subroutines of a program, or more generally to any element of a program or software capable of implementing a function or a set of functions, as described below for the module concerned. Such a software component is executed by a data processor of a physical entity (user equipment, server, gateway, set-top-box, router, etc.) and is likely to access the hardware resources of this physical entity (memories, recording media, communication buses, electronic input / output cards, user interfaces, etc.). Subsequently, resources are understood to mean all sets of hardware and / or software elements supporting a function or a service, whether unitary or combined. 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, as described below for themodule concerned. It may be a programmable hardware component or one with an integrated processor for executing software, for example an integrated circuit, a smart card, a memory card, an electronic card for executing firmware, etc. Each component of the system described above of course implements its own software modules. The different embodiments mentioned above can be combined with each other for implementing the present technique. Brief description of the figures 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: [fig.1] schematically represents the different elements involved in the implementation of the present solution, for user equipment connected to a first access equipment, calledserver equipment, of a first communication network located in a geographical area in which this first access equipment and other access equipment of other communication networks coexist, configured to transmit radio signals in the same frequency band as it; [fig.2] represents an illustrative example of architecture of a system comprising the server equipment of the first communication network, the user equipment, at least one second communication network and a device for controlling a level of quality of service of a communication between the server equipment and the user equipment according to the invention; [fig.3] represents the steps of a method for controlling a level of quality of service of a communication between the server equipment and the user equipment according to an embodiment of the invention; [fig.4A] represents user equipment connected to a terrestrial base station serving the first communication networkcommunication; [fig.4B] represents the sectors covered by three sector antennas of the serving terrestrial base station; [fig.5] schematically represents an example of relative positions of a user equipment and a satellite access equipment of the second communication network; [fig.6] details the determination of a useful reception rate of the data transmitted by the server access equipment of a communication network to a user equipment according to an embodiment of the invention; [fig.7] schematically represents an example of relative positions of a user equipment and a drone-type radio access equipment of a third communication network present in the geographical area; and [fig.8] presents an example of hardware structure of a device allowing the implementation of the steps of the method for controlling a level of quality of service according to an embodiment of the invention. Detailed description ofthe invention General principle of the invention The invention relates to the control of a level of quality of service of a communication established on a downlink radio link between an access device, called server device, of a first wireless communication network and a user device located in a geographical area where other wireless communication networks coexist with the first network and whose access devices use the same resources as the first network, and in particular here the same frequency band. Consequently, these other access devices when they emit radio-frequency beams on this frequency band are likely to generate interference with the radio-frequency beams emitted by the server device on this same frequency band towards the user device. For the sake of simplification here, it is said that these other access devices are therefore likely to interfere with the communication between the deviceserver and the user equipment, and are referred to as interfering access equipment. The general principle of the invention is based on determining a value of a parameter representative of an effective quality of service level of the communication between the server equipment of the first network and the user equipment at least as a function of a bandwidth allocated to this communication, transmission characteristics of the server equipment, at least one other access equipment of the first network and at least one other access equipment of at least one second wireless communication network, said other access equipment being likely to interfere with the communication, and a topology of the first network and of the at least one second network in at least one so-called interference zone. In the embodiment described here, the value of the parameter is determined at least as a function of the bandwidth allocated to this communication, a distance betweenthe user equipment and the server equipment, a transmission power of the server equipment, antenna gain ratios between the server equipment and said at least one other access equipment of the first network and between the server equipment and said at least one other access equipment of the at least one second network, and the topology of the first network and of the at least one second network in said at least one interference zone. According to the invention, the determined value is compared with a target value of said parameter. Thus, the invention makes it possible to check that the target quality of service level is achieved and, if this is not the case, to propose a modification of the configuration of one or more access equipment of the first network and / or of the other networks present in the geographical area and likely to interfere with the communication, to ensure that it is achieved. Here, a parameter representative of a quality of service level is designated as anyparameter which makes it possible to characterize a data transmission performance on the radio link considered. This is for example a useful data reception rate by the user equipment UE or a data transmission delay or even a useful data reception power. The modification of a configuration of the transmission characteristics may concern one or more antennas of the server equipment to which the user equipment is connected, but also one or more antennas of one or more other access equipment of the first network or other communication networks present in the geographical area considered. The modified transmission characteristics may include for example the antenna gain, the transmission power or even the transmission bandwidth in the frequency band considered. The invention thus makes it possible to guarantee to a user equipment the quality of service and the performances required for the execution of agiven service, for example by an application installed on a mobile terminal, such as a smartphone. It can advantageously be integrated into a planning tool used by an operator to decide on the installation of its access equipment in a given geographical area. The invention works with both SISO (Single Input Single Output) and MIMO (Multiple-Input Multiple-Output) technology. The first network and the other communications networks are distinct and potentially heterogeneous networks, in the sense that they may rely on different technologies and include access equipment of different types. For example, the first network is a terrestrial communications network comprising terrestrial base stations and the second network is a so-called "aerial" communications network, comprising access equipment located in theair like drones or in space like satellites. Of course, the invention is not limited to this example of a second satellite network and applies to other types of network, such as for example a drone network or a high-altitude platform network. It is further assumed that the user equipment can be attached to any type of access equipment, belonging to any of the previously mentioned communication networks. In the following, we will describe the case of a first terrestrial type communication network, for example based on an OFDMA type radio access technology, such as for example a mobile communication network conforming to one of the current versions 4G LTE-A or 5G or a future version (6G and following) defined by the 3GPP standard. In the detailed example below, we consider a second satellite communication network (network of the "aerial" type within the meaning of the invention), also implementing aOFDMA type radio technology and compliant with the 3GPP standard in one of its versions from the fourth generation (4G and following), and likely to interfere in a given geographical area with communications transmitted via the first terrestrial communication network. Of course, the invention is not limited to this example and applies more generally regardless of the type of wireless communication network and the radio technology implemented, provided that their access equipment is configured to transmit on the same frequency band. In relation to Figure 1, a user equipment UE is presented, for example a mobile telephone or a laptop or any other radio transmitter / receiver integrated in a vehicle or in a connected object located in a geographical area ZG, connected to a first radiocellular communication network RT of an operator. This is for example an urban or semi-urban area, within which severalterrestrial base stations BS1, BS2, BS3 of the RT network have been installed close to each other. Their radio coverage areas or cells CL1, CL2, CL3 may overlap and, depending on its location in the ZG zone, the user equipment UE may be simultaneously within radio range of several of them. In this example, above the geographical zone ZG, there are various satellite access equipment SAT1, SAT2, located in space, orbiting the Earth at approximately 600 km, these satellite access equipment belonging to a second satellite radio communication network RSAT. It should be noted that, even if only a few satellite access equipments within the ZG zone belonging to a single satellite network RSAT have been shown, their number is in reality much higher, of the order of a few units to a few dozen units depending on the dimensions of the geographical zone considered, these being able to belong to a plurality of networksdistinct. This second RSAT network may or may not be managed by the same operator as the first network. Each access equipment of the ZG zone is equipped with one or more antennas configured to emit one or more radio frequency beams in one or more propagation directions, in a manner known per se. It is assumed in the following that the user equipment UE is attached to the base station BS1 of the first network RT. An example of the architecture of a system S, 10 according to an embodiment of the invention is now presented in relation to FIG. 2. Such a system comprises access equipment of a first communication network RT, access equipment of a second RSAT network and the user equipment UE of FIG. 1. According to the invention, the system 10 further comprises a device 100 configured to control a level of quality of service of a communication established between the user equipment UE and a serving base station, namelyin the example envisaged here, the server base station BS1. In this exemplary embodiment, such a device comprises a DET.QoS_U module for determining a value of a parameter representative of the level of quality of service of the communication between the server base station BS1 and the user equipment UE, at least as a function of a bandwidth allocated to this communication, a distance between the user equipment and the server base station BS1, a transmission power of the server base station and antenna gain ratios between the server base station and at least one other access equipment of the first network and between the server equipment and at least one satellite of the second RSAT network configured to use said given frequency band and likely to interfere with the communication, and a topology of the first network RT and of the at least one second RSAT network in at least one so-called interference zone. The device comprisesalso a module MOD. TXF for obtaining a modification of at least one transmission characteristic of said server access equipment and / or of at least one other access equipment of the first and / or of the at least one second network, depending on the target value, configured to be implemented when the determined value does not reach a target value of said parameter. Advantageously, it also comprises a module OBT. QoS_T for obtaining the target value of the parameter representative of the level of quality of service and a module APP for implementing the modification obtained. The device 100 thus implements the method for controlling a level of quality of service according to the invention which will be described in more detail in relation to FIGS. 3 and 6. In the example of FIG. 2, the device 100 is housed in the first network RT and for example integrated into the server base station BS1, which conventionally comprises memories MEM associated with a processor CPU. The memoriescan be of the ROM (Read Only Memory) or RAM (Random Access Memory) or Flash type. The base station BS1 further comprises a TX module configured to control the transmission / reception of radiofrequency beams by its antenna(s) (not shown) depending on the type of technology used. It also comprises another interface INT, for example wired, for communication with node equipment of a core part RC of the first communication network RT. Alternatively, the device 100 could be integrated into another radio access equipment of the first network RT or into a node equipment of the core network RC. According to another variant, it is integrated into the user equipment UE. We now present, in relation to FIG. 3, the steps of the method for controlling a quality of service level according to an embodiment of the invention in the environment illustrated by FIG. 2. During a step 30, a target value QoS_T of a parameterrepresentative of a quality of service level of a communication established on the downlink radio link between the server base station BS1 and the user equipment UE is obtained. For example, this target value is received from the user equipment UE in a request message sent by a dedicated application installed on the user equipment. This is for example an application which implements video data streams and which needs to operate a target useful data reception rate and / or a target bandwidth in order to guarantee the quality of the images returned to the user, or an application which implements voice streams which requires a transmission delay less than a target value to guarantee real-time communication. Alternatively, the target value of the parameter may be stored in memory, for example in a data table of the first network RT storing a user profile or a configuration ofquality of service associated with the application in question and accessible by the device 100. At 31, an effective value of the quality of service parameter is determined for a given transmission on the downlink radio link between the server base station and the user equipment UE, at least as a function of a bandwidth allocated to this communication, a distance between the user equipment and the server base station, a transmission power of the server base station BS1 and antenna gain ratios between the server base station and at least one other access equipment of the first network and between the server equipment and at least one satellite of the second RSAT network configured to use said given frequency band and likely to interfere with the communication, and a topology of the first network RT and of the at least one second RSAT network in at least one so-called interference zone. A detailed example of determining this parameterwill be detailed below in relation to Figure 6. At 32, the effective value of the quality of service parameter determined at 31 is compared with the previously obtained target value. Depending on the result of this comparison, it is decided at 33, when the effective value reaches the target value, that the configuration of the communication system 10 can be left as is, and otherwise to modify the value of at least one TXF transmission characteristic of at least one antenna of at least one access device of the communication system 10. It is understood that depending on the type of parameter representative of a level of quality of service considered, the determined effective value may not reach the target value because it is lower than it (for example in the case of a useful data reception rate) or on the contrary because it is higher than it (for example in the case of a useful data reception delay). Alternatively, it is also possible to envisage, when the valueeffective reaches the target value and exceeds it, to modify the value of at least one transmission TXF characteristic of at least one antenna of at least one access equipment of the communication system 10, for example to further optimize the transmission parameters of the communication system 10, while ensuring that the target throughput requirement remains met. At 34, the required modification is determined. It may be intended to apply to the antenna(s) of the server base station BS1 or to the antennas of other access equipment of the first RT network and / or the second RSAT network located in the interference zone. It is assumed, for example, that the quality of service parameter taken into consideration is the useful data reception rate by the user equipment and that the determined effective value is lower than the target value. According to a first embodiment of the invention, the decided modification comprises an increase in the powertransmission power of the base station BS1. Alternatively, it comprises a reduction in the transmission power of other access equipment, for example satellites SAT1, SAT2 of the second network RSAT or possibly other base stations BS2 and BS3 of the first network RT. According to a second embodiment, the modification relates to a bandwidth of the communication system, i.e. the frequency bandwidth actually used by the system within the authorized frequency band. For example, the frequency band authorized by the 3GPP standard in a network is approximately between 2680 and 2690 MHz, which makes a bandwidth of 10 MHz, whereas the bandwidth of the frequencies actually used by an access equipment is only 2 or 3 MHz. This bandwidth can therefore be increased or decreased in order to meet the throughput requirement, and to optimize the use of the bandwidth allocated to transmission.According to a third embodiment of the invention, the modification relates to the antenna gain of the base station BS1 if such a possibility of intervention on the antenna gain of the base station is offered by the network RT. According to another embodiment, the modification relates to several of the aforementioned transmission characteristics. At 35, the modification obtained is implemented. Several embodiments can be envisaged. Upstream of a communication: it then allows the operator of the first network to know a priori whether a server access equipment responds to a quality of service requested by a user equipment. The implementation 35 of the modification obtained can comprise the sending of a command message for updating a configuration of the access equipment, specifying the new value of the transmission characteristic(s) concerned. If it is not possible to modify the transmission characteristics of the equipmentserver access as determined in 34, an alert message can be sent to another device or another function of the first network, for example in charge of supervising the management of the quality of service, so that it triggers different actions aimed at improving the user experience (information of the user, rejection of the communication, selection of another access device to serve the communication, etc.). Alternatively, it is possible to consider taking this impossibility into account and determining a modification that can be applied to another access device of the first network and / or the second network. In an alternative, when the modification obtained concerns other access devices of the first network or interfering access devices of the second network, command messages for updating their configuration are sent directly to them, in the case where the operator of the first network is also the operator of the second network. Otherwise,when the second network is operated by another operator, an update request message may be sent to the second network, in accordance with the terms of an inter-operator agreement. The implementation of the modifications obtained may also be executed during communication to dynamically adapt one or more transmission characteristics of this communication, such as the transmission power of the server access equipment, the bandwidth allocated to the communication or the flow rate of the communication. Alternatively, the invention may also be implemented in a tool for planning the deployment of terrestrial, airborne or space access equipment, for example to adapt the transmission characteristics of the access equipment of the first and / or second network, following the installation of a new base station in the first network or the placing in orbit of an additional satellite in the geographical area considered.now details an example of determining an effective value of a quality of service parameter (step 31 of the method which has just been described) according to an embodiment of the invention. In this example, it is always considered that the user equipment UE is attached to the server base station BS1, an example of configuration of which is now described in relation to FIGS. 4A and 4B. In the present application, a base station is defined as being dedicated to the management of a given geographical site (for example the geographical site of the base station BS1 corresponds to the cell CL1 of the network). In the case of FIG. 4A, the first base station BS1 manages the corresponding geographical site in a multi-sector (or multi-sector) manner. More particularly, the first base station BS1 of FIG. 4A covers the site via three distinct sectors, each sector being covered by a corresponding so-called sector antenna A11, A21, A31. In the presentrequest, a sector antenna is understood to mean an antenna emitting mainly in a given propagation direction. For example, a cell of the radiocommunications network comprises three sectors. The three sectors are assumed here to have identical dimensions. For the sake of simplification, it is assumed that each sector is defined by an angle, θb1, of misalignment in the horizontal plane which in this example is θb1 = 120°. It should be noted that other values ​​of misalignment angles can be chosen. Each sector is covered by means of a single antenna A11, A21, A31 capable of emitting according to a single beam in a given propagation direction (or at least a single main beam concentrating the majority of the power radiated by the antenna) on a given frequency band. In Figure 4A, for the sake of simplification, this propagation direction is referenced identically to the corresponding antenna A11, A21 or A31. In other words, the directionspropagation (or radiation) of the beams emitted by the antennas A11, A21, A31 covering two adjacent sectors of this site have between them an angle equal to θb1. Each antenna A11, A21, A31 is characterized, in a manner known per se, by a radiation pattern. For example, we consider antennas as described in the ITU-R Report M.2135-1 document, entitled "Guidelines for evaluation of radio technologies for IMT Advanced" of December 2009. The radiation pattern of each antenna A11, A21, A31 has an opening angle of three decibels in the horizontal plane noted θ3dB. The antennas A11, A21 and A31 are co-located at the base station BS1, the latter being located at a point in the cell covered by the base station BS1, for example at the center O1 of the cell in the example envisaged in Figure 4A. Note that by "co-located" is meant that the antennas A11, A21, A31 are located at the same site (i.e.here of the same base station). However, they are not necessarily positioned at the same geographical point (corresponding to an ideally zero distance between the antennas) and can be separated by a few centimeters or a few tens of centimeters, or even a few meters. For example, the antennas can be spaced apart by a distance less than λ / 2 where λ denotes the wavelength of the signals emitted by antennas A11, A21 and A31 to communicate on the network. Alternatively, they can be spaced apart by a distance greater than λ / 2. Note that in an urban environment, we will preferably limit ourselves to a spacing less than a distance ranging from 3 to 5 meters; in a rural environment, a greater spacing can be considered, the cells covering larger areas. In the example considered here, for the sake of simplification, we assume that the antennas A11, A31 and A21 are located at the same point O1' situated at the top of a pylon ofthe base station BS1. As illustrated in Figure 4A, the user equipment UE is located relative to the first base station BS1 in an orthonormal reference frame O1xyz. The origin O1 of the reference frame is here located at the foot of the pylon of the base station BS1 supporting the antennas A11, A21 and A31, at ground level. The axis O1z is vertical (along the pylon here, parallel to it) and the axes O1x and O1y define a horizontal plane parallel to the ground and perpendicular to the pylon. In the example considered here, the plane (O1xy) is at ground level and is tangent to the Earth's surface at point O1 located at the foot of the pylon. The axis O1x coincides with the projection of the main propagation direction of the antenna A11 onto this horizontal plane parallel to the ground. Here, the direction of observation of the user equipment UE by an antenna of the base station is designated as its direction seen by this antenna. We also consider the reference O1'xyz whose origin O1' is located at the top of thepylon, at a height h from the ground, and more specifically at the point where the antenna A11 is located (and in the example considered here, the two antennas are assumed to be co-located at the same point for the sake of simplification, as mentioned above). For example, the user equipment UE is located via angles of a spherical coordinate system (θ11, Φ11) in the O1'xyz frame in question, and by the distance r representing the projection in the horizontal plane O1xy of the distance of the user equipment UE with respect to the origin O1' of the O1'xyz frame. It is assumed here for the sake of simplification that the user equipment UE is located in the horizontal plane O1xy, at ground level (the height at which the user equipment is located with respect to the ground is neglected). In other words, in Figure 4B, r represents the distance of the user equipment UE from the foot of the pylon located at O1, supporting the antennas A11, A21, and θ11 and Φ11 respectively representingthe longitude and latitude of the user equipment UE in the O1'xyz coordinate system. The angle θ11 is thus defined via the projection of the vector joining the origin of the O1'xyz coordinate system to the user equipment UE in the horizontal plane O1xy, and measured with respect to the projection of the main propagation direction of the antenna A11 in this plane (which coincides with the O1x direction). The coordinates (r, θ, φ) define the relative position of the user equipment UE with respect to the base station BS1, i.e. taking the position of the first base station BS1 as a reference. This position of the base station BS1 is known to the first network RT. The antennas A11, A21, A31 emit radiofrequency beams at an inclination angle φ t11 (or tilt angle in English) corresponding to an offset angle (an offset latitude here) of their radiation pattern relative to the horizontal plane O1'xy. Such sectoral antennas A11, A21 and A31are for example adapted to a so-called SISO (for "Single Input Single Output" in English) implementation of the radiocommunications network considered, but also to a MIMO implementation, according to which the sector antennas are matrices or networks of radiating elements. In the following, we will describe an exemplary embodiment of the invention in the SISO case. In Figure 4A, the antennas A11, A21 and A31 are located at a height h which corresponds to the distance between the antennas and the ground. In other words, the plane O1'xy is located at a height h relative to the plane O1xy. We will now detail, in relation to Figure 5, an example of determining the effective value of a quality of service parameter according to an embodiment of the invention. In this example, the user equipment UE is attached to the server base station BS1 first network RT of Figure 2 and the base station BS1 has the architecture of Figures 4A and 4B. It is assumed here thatthe user equipment UE receives one or more radiofrequency beams from the antenna of the first sector of the serving base station BS1. At 311, a terrestrial impact factor Fb of the other terrestrial base stations on the level of quality of service of the downlink radio link between the base station BS1 and the user equipment UE is determined. According to the invention, this impact factor depends on a density of the other terrestrial base stations of the first network likely to interfere with the communication between the serving base station BS1 and the user equipment, i.e. located in a terrestrial interference zone (ZIT in Fig. 4B). They are referred to as interfering base stations. This terrestrial interference zone ZIT is defined as a ring centered on the serving base station BS1, with a first radius being the average inter-site distance ISD and a second radius defined by the limits of the geographical zone ZG. This factorterrestrial impact Fb represents the sum of the powers of each of the base stations of the first network RT which are located in the terrestrial interference zone ZIT. A first simplifying hypothesis is that all the base stations of the first network RT transmit with the same transmission power and the same maximum antenna gain given. A second is to consider that the sum of the discrete contributions of the powers transmitted by the base stations located in the terrestrial interference zone can be transformed into a continuous spherical integration of the density of the interfering base stations all around the base station, therefore over an angular interval [0, 2 π ] and for a radius r' between ISD and a maximum value defined by the limits of the geographical zone ZG. A third hypothesis is that the user equipment UE is served by the antenna(s) of the first sector of the serving base station BS1. A fourth hypothesis is thatthe antennas of the other sectors of the serving base station use the same frequency band and are therefore likely to generate interference with the communication. Based on these assumptions, the inventor established that this terrestrial impact factor could be defined from the following relationship: where ISD denotes the average distance between the serving base station and the interfering base stations, ρ B denotes the density of base stations in the terrestrial interference zone, δ denotes the fading factor (from the English, “path-loss”) modeling the propagation attenuation, r the radius or distance between the user equipment and the first antenna, h the height of the first antenna relative to the user equipment,

[0040] (r, θ, φ ) denotes the spherical coordinates of the user equipment in a reference frame O1'xyz centered on the serving base station at ground level, θ the elevation angle between the user equipment and said first antenna,

[0041] Φ the horizontal angle between the user equipment and said first antenna,

[0042] A(θ, φ ) is the angular gain of the first antenna of the serving base station, to which the user equipment UE is connected.

[0043] The user equipment UE is connected to the first sector of the serving base station BS1, whose antenna gain is therefore A(θ,φ ) dB .

[0044] It receives interfering powers from all other antennas in the first network.

[0045] These interferences are proportional to:

[0046] It also receives interference from the other two sectors which in this example use the same frequency band as the first sector. This interference is proportional to A(θ2, φ2) + A(θ3, φ3).

[0047] A(θ k , φ k ) the angular gain of each of the other two antennas (k=2, 3) of the serving base station, co-located with the first antenna of the serving base station.

[0048] H1 is the gain of each antenna of the first RT network, defined as follows by: denotes the minimum antenna gain, and is a constant,

[0049] , where φ tilt is the downward tilt angle, φ 3dB the width of the half-power vertical beam, θ 3dBthe width of the horizontal beam at half power, and a contribution from the other two antennas of the serving base station uses a relationship equivalent to the following relationship: denotes respectively the other two antennas of the base station waitress.

[0050] Thus, according to this embodiment of the invention, it is not useful to know the absolute positions of each of the other base stations in the geographical area ZG. On the contrary, the invention proposes to estimate in a simple and global manner their impact on the communication established on the downlink radio link between the base station BS1 and the user equipment UE. At 312, a satellite impact factor FSAT is determined as a function of a density of satellites of the second network placed in orbit above the geographical area ZG and likely to interfere with the communication. They are referred to hereinafter as interfering satellites. In relation to FIG. 6, they are located in a satellite interference zone ZIS which will be defined hereinafter. In the embodiment described here, this is a spherical cap corresponding to a portion of the sphere SPH having as its radius the orbit of the satellites SAT1 SAT2 of the satellite network RSAT.More specifically, the satellites of the RAT satellite network which simultaneously use the same resources as the base station BS1 uses to communicate in downlink with the user equipment UE, such as the same frequency band, are considered likely to generate interference on the communication between the server base station BS1 and the user equipment UE, such as for example the same frequency band. It is assumed here that all the satellites of the RSAT satellite network in direct visibility with the user equipment UE satisfy this condition for the sake of simplification, i.e. the satellites located in the portion of the sphere ZIS of the sphere SPH delimited by the horizontal plane Δ orthogonal to the radius RT of the Earth at a point where the user equipment UE is located (i.e. tangent to the Earth at the user equipment UE).It is noted that this assumption is realistic because in such a satellite network, a priori all the satellites of the network are used to transmit data to users of the satellite network and configured to exploit all the resources at its disposal in order to maximize the network performance. As a result, the simultaneous use of the same resources by all the satellites of the satellite network is an assumption that a satellite network verifies with a high probability. If this assumption is not verified for the satellite network considered, it is sufficient to limit the study to the satellites located in the portion of the ZIS sphere simultaneously using the same resources (e.g. same frequency band here) that the base station BS1 uses in downlink to communicate with the user equipment UE.Furthermore, the inventor has found that below a certain elevation angle relative to the user equipment UE, noted ^^, typically ^^ = 30°, hereinafter called the minimum elevation angle, the interference generated by the satellites located in the ZIS zone has only a small impact on the performance of the communication between the server base station BS1 and the user equipment UE and can be neglected, so that in the remainder of the description an interference zone ZIS corresponding to the spherical cap delimited by the disk parallel to the plane Δ αcorresponding to an elevation angle relative to the user equipment UE equal to a is considered. It is noted that the value 30° is a typical value provided by satellite manufacturers, but the invention applies to other values ​​of a (for example to values ​​lower than 30°).

[0051] Ingeniously, the inventor evaluated globally (rather than individually for each satellite) the interference generated by all the interfering satellites located in the ZIS zone thus defined. To this end, he considered the topology of the RSAT satellite network in this ZIS zone and more specifically, in the embodiment described here, the density ρ SAT satellites likely to interfere with communication located in the interference zone ZIS (i.e. number of satellites per unit area), the altitude h SAT of the interfering satellites, as well as the minimum elevation angle a of the interfering satellites and therefore located in the interference zone ZIS (namely here α =

[0052] 30°).

[0053] Alternatively, it is possible to consider other elements representative of the topology of the satellite network such as for example the probability that a satellite generates interference affecting the communication between the server base station BS1 and the user equipment UE, in other words, the probability that the satellite in question is located in the interference zone ZIS.

[0054] Note that if the satellites in the satellite network have different altitudes, the same reasoning applies to each subset of satellites located at the same altitude, the overall contribution of the satellites being obtained by summing the contributions of each subset for each different altitude (we then consider a distinct density per different altitude).

[0055] In relation to Figure 6, we consider a spherical coordinate system (d SAT, τ ,β ) centered on the user equipment, where dsAj is the distance between the user equipment UE and the satellite

[0056] SAT1, τ is the longitude angle (horizontal) and β the latitude or elevation angle (vertical).

[0057] For such a satellite, located at an elevation angle β, it can be shown by geometric considerations and the implementation of trigonometric relations that the distance d SAT is written:

[0058] The density of satellites present in the satellite interference zone ZIS is expressed as follows: where N SATis the number of interfering satellites in the ZIS zone and S the surface (not shown in Figure 6) of the spherical cap CS in which the interfering satellites for the user equipment UE operate above the geographical zone ZG (which therefore corresponds to the ZIS zone). The spherical cap CS is located beyond the minimum elevation angles α and π — a.

[0059] S = 2 π(R T + h. SAT ) 2 (1 — costhetamax) (5) , costhetamax where d M denotes the distance between the user equipment UE and a satellite located at this angle a.

[0060] This distance of M is written:

[0061] To determine the impact factor F SAT, the inventor made the (realistic and highly probable) assumption that the gain ratio G and the power P are the same for all satellites likely to interfere with communication located in the ZIS zone: in fact, the antenna of a satellite emits an extremely narrow beam and if we assume that the user equipment UE is not in the coverage of the main lobe of the radiation pattern of the antennas of these satellites (which would otherwise be server satellites for the user equipment

[0062] UE), it is common to consider (see technical specifications of satellite networks) that the same gain applies in the direction of the user equipment UE outside this main lobe, for example -30dB compared to the maximum gain of the main lobe of the antenna. In addition, to maximize the throughput that can be achieved during a communication, it is classic to configure

[0063] (all) satellites to transmit with the maximum authorized power Pmax (P=Pmax).

[0064] According to the invention and on the basis of this hypothesis the impact factor F SAT is defined by the density

[0065] P sat of interfering satellites in the interference zone ZIS, integrated by a double spherical integration corresponding to the surface S of the spherical cap CS.

[0066] We obtain:

[0067] Where τ varies between 0 and 2 π .

[0068] We deduce the following expression for the factor F SAT :

[0069] At 314, the transmission power Pb from the serving base station to the user equipment UE is determined. Conventionally, the angular position of the user equipment UE relative to the base station BS1 and the radiation pattern model of the antenna of the first sector of the base station BS1 which transmits at least one radiofrequency beam intended for this user equipment. In relation to FIG. 4B already described, the radiation pattern characterizes the gain of the antenna as a function of an observation direction (θ, Φ) of the user equipment UE in the reference frame O1'xyz.

[0070] In addition, this determination takes into account the terrestrial impact factors Fb and satellite F SAT previously described, which allows the power received by the user equipment to be expressed as follows: with:

[0071] W the bandwidth used for communication on the downlink radio link between the first base station and the user equipment,

[0072] From the useful data reception rate by the user equipment UE,

[0073] P SAT : transmission power of a satellite, based on the assumption that all SAT1, SAT2 satellites in the ZG zone transmit at the same power,

[0074] G SAT satellite gain

[0075] G b the gain of the base stations,

[0076] K SAT a satellite propagation constant

[0077] Kb a propagation constant of base stations and

[0078] N th thermal noise.

[0079] We remind you that:

[0080] ISD designates the average inter-site distance, and in particular between the first serving base station BS1 and the other base stations of the first RT network,

[0081] K is a propagation constant of the base stations, r denotes the distance separating the user equipment UE from the serving base station BS1 at ground level, h the height of the antennas of the serving base station relative to the ground, δ is a fading factor (also called “pathloss” factor) modeling the propagation attenuation with the distance,

[0082] A(θ, φ) is the angular gain of the antenna of the first sector of the server base station BS1. At 315, we deduce the useful data reception rate Du by the user equipment UE: Alternatively, another parameter representative of a level of quality of service on the downlink radio link between the server base station BS1 and the user equipment UE can be determined, such as for example the useful reception delay DRu or the useful reception power Pu. For a volume V of data transmitted by the server base station BS1, the transmission delay DR U can be written as follows: The invention therefore makes it possible to obtain relatively simply the effective value of one or more parameters representative of a level of quality of service of the communication between the server base station BS1 and the user equipment UE. According to another exemplary embodiment of the invention, in addition to the first network RT and the second network RSAT, a third communication network is considered, for example of the aerial type, comprising a plurality of access devices present in the air above the geographical zone ZG where the user equipment UE is located. It is considered here that this is a network of drones RD and it is assumed that the drones of this network use the same frequency band as the server base station BS1 and are therefore likely to generate interference on the communication between the server base station BS1 and the user equipment UE.According to this example, in 313, a drone impact factor Fd is determined as a function of a density ρ. d drones Dr located in a drone interference zone ZID. In relation to Figure 7, we consider that the drones Dr present above the geographical zone ZG are placed at an altitude h d , of the order of a few hundred meters and we rely on the same assumptions as those of the satellite network, namely that all drones Dr transmit with the same power and the same gain and that the interference zone of the drones is defined as a spherical cap CSD of radius dd and delimited by a minimum elevation angle α d below which drones do not generate interference with the communication between the serving base station BS and the user equipment UE. Based on these assumptions, the impact factor Fd is defined by the density p dof interfering drones in the interference zone ZID, integrated by a double spherical integration corresponding to the surface Sd of the spherical cap CS d .

[0083] We obtain:

[0084] Where T varies between 0 and 2 π , ρ d denotes the density of interfering drones, i.e. located at a minimum elevation angle α d relative to the horizontal plane A orthogonal to the radius R T from the Earth at a point where the user equipment UE is located (i.e. tangent to the Earth at the user equipment UE).

[0085] We ask: where R T : is the radius of the Earth, h d is the altitude of the drones. We assume here that they are all located at the same altitude for the geographical zone ZG, dα d is the distance between the ground receiver and a drone at the minimum elevation angle α d .

[0086] The density of interfering drones is determined as follows: ρ d = N d / S d (4bis) where N d denotes the number of interfering drones present in the interference zone ZID and S d the surface of the spherical cap located between the minimum elevation angles α d and π — α d .

[0087] S d = 2π (R T + h d ) 2 (1 — costhetamax d ) (5bis)

[0088] The distance dα d is written:

[0089] The F factor d of expression (3bis) is therefore written:

[0090] In the case of a communications system S also comprising drones, the expression of the useful flow rate obtained in 315 becomes: where ^^ ^^ denotes the gain of the drones, P dthe transmission power of the drones, and Kd a transmission constant of the drones. Of course, according to another exemplary embodiment, one could consider the presence of a fourth communication network in the geographical area, for example a network of high-altitude platforms and determine an impact factor of these platforms in a similar way to what has just been described in the case of a network of drones. Once the effective or useful value of the quality of service parameter QoS_U, for example the useful rate Du, is obtained, it is compared to the target value at 320 as previously described in relation to Figure 3.When it is established at 330 that the effective value of the parameter representative of a level of quality of service does not reach the target value, it is decided to modify a value of at least one transmission characteristic of at least one antenna of one of the communication networks present in the geographical area, according to one of the embodiments previously described. This is for example the antenna gain Gb and / or the transmission power Pb of the base stations of the first network R. T and or the bandwidth W. Alternatively, it may also be the GSAT gain of the satellites and / or the PSAT power of the satellites of the second RSAT network. This modification is determined at 34 as a function of the target value and with a view to approaching this target value. For example, for a target value D u_Tof the useful data reception rate by the user equipment UE, the transmission power Pb of the server base station BS1 is modified into a power Pb', from equation (9), as follows: all other transmission parameters (including those of the interfering access equipment) being kept constant elsewhere. In particular, the transmission power Pb of the other interfering base stations of the first network is unchanged. According to another example, if it is decided to modify the bandwidth W used by the server base station BS1 so as to reach the target value D u_T of the useful data reception rate by the user equipment UE, its new value W' is determined from the following relationship, derived from one of the applicable equations (10) or (10bis). Thus, by way of illustration, in the presence of a second satellite network and a third drone network, we obtain, from equation (10bis): _all other parameters being kept constant elsewhere (including those of the interfering access equipment). In particular, the bandwidth of the other base stations of the first network is unchanged. A similar procedure could be followed for the antenna gain. Alternatively, the modified value of the transmission parameter that is intended to be modified is obtained via numerical simulations or experimentally. In another embodiment, the transmission parameters of the other base stations of the first network and / or of the other access equipment of the other networks present in the geographical area are modified.To do this, the person skilled in the art can use in particular the relationships described above by replacing the value of the quality of service parameter considered by the target value that one seeks to achieve, and by extracting from these relationships the value to be given to the transmission parameter that one plans to modify to achieve this target value, or by obtaining the modified value of said transmission parameter by relying on numerical simulations. In the exemplary embodiments of the invention that have just been presented, the server equipment of the user equipment UE is a terrestrial base station of the first network RT. Of course, the invention also applies in the case where the first network is an aerial type network and the server equipment is a satellite, a drone or a high-altitude platform.The person skilled in the art would be able to adapt the method for controlling a level of quality of service of the invention to the specificities of such aerial access equipment, based on this general knowledge and on the principles and hypotheses previously described. In particular, in the case where the server equipment is a satellite, he would obtain: We now present, in relation to Figure 8, an example of hardware structure of the device 100 making it possible to implement the steps of the method for controlling a level of quality of service on the downlink radio link between the base station BS1 and the user equipment according to the invention. The device 100 comprises a random access memory 103 (for example a RAM memory), a processing unit 102 equipped for example with a processor μP, and controlled by a computer program stored in a read-only memory 101 (for example a ROM memory or a hard disk). At initialization, the code instructions of the computer program are for example loaded into the random access memory 103 before being executed by the processor of the processing unit 102. This fig.8 illustrates only one particular way, among several possible ways, of producing the device 100 so that it performs the steps of the control method (according to any one of the embodiments and / or variants described above in relation to FIGS. 3 and 5). Indeed, these steps can be performed indifferently on a reprogrammable computing machine (a PC computer, a DSP processor or a microcontroller) executing a program comprising a sequence of instructions, or on a dedicated computing machine (for example a set of logic gates such as an FPGA or an ASIC, or any other hardware module).In the case where the device 100 is produced with a reprogrammable computing machine, the corresponding program (i.e. the sequence of instructions) may be stored in a removable storage medium (such as for example a CD-ROM, a DVD-ROM, a USB key) or not, this storage medium being partially or totally readable by a computer or a processor. In certain embodiments, the device 100 is included in the access equipment to which the user equipment UE is attached, for example the server base station BS1 of the first communication network RT. In certain embodiments, the device 100 is included in a device of the first communication network RT, e.g. in a node of the first communication network RT or in another access equipment of this first network, for example one of the base stations BS2 or BS3.It can also be integrated into the user equipment UE or into access equipment or node equipment of another communication network present in the geographical area and included in the system 10 according to the invention, such as for example the second RSAT network.

Claims

CLAIMS 1. A method for controlling a quality of service level of communication between a user device (UD) and a first wireless communication network (WTN), characterized in that said method comprises: - the determination (310) of a value of a parameter representative of the quality of service level of the communication between an access device called server equipment (BS1) of the first network to which said user device is attached and said user device (UD), said communication using a given frequency band, said value being determined at least as a function of a bandwidth (W) allocated to this communication, transmission characteristics of the server equipment, at least one other access device of the first network and at least one other access device of at least a second wireless communication network (RSAT, RD),said other access equipment being configured to use said given frequency band and being likely to interfere with communication, and of a topology of the first network and at least one second network in at least one so-called interference zone (ZG, CS); - when the determined value does not reach a target value of said parameter, obtaining a modification (34) of at least one transmission characteristic of said server access equipment and / or at least one other access equipment of the first and / or at least one second network, depending on the target value.

2. Control method according to claim 1 characterized in that said parameter value is determined at least as a function of the bandwidth allocated to communication, a distance between the user equipment and the server equipment, a transmission power of the server equipment,of antenna gain ratios between the server equipment and said at least one other access equipment of the first network and between the server equipment and said at least one other access equipment of the at least a second network, and of the topology of the first network and of the at least one second network in said at least one interference zone.

3. Control method according to claim 1 or 2, characterized in that the first network and the second network are networks of distinct types belonging to a group comprising at least one terrestrial-type network comprising a plurality of terrestrial base stations and one aerial-type network comprising a plurality of aerial or space access equipment, and in that the determination of a value of a parameter representative of the communication quality of service level includes the determination of a first impact factor of the others, access equipment of the first network and the determination of a second impact factor of said access equipment of the second network on the value of said parameter.

4. Method according to claim 3, characterized in that the first network being a terrestrial type network and the server equipment a terrestrial base station (BS1), the determination of the first impact factor, called terrestrial impact factor (Fb), is a function of a density of other terrestrial base stations of the first network, called interfering base stations, located in a terrestrial interference zone defined at least as a function of an average distance (ISD) between the base stations of the first network.

5. Method according to claim 4, characterized in that, the first base station comprising a first, a second and a third antenna forming three sectors, the determination of the terrestrial impact factor (Fb) comprises the implementation of a relationship equivalent to the following relationship: where ISD denotes the average distance between the serving base station and the interfering base stations, ρ B denotes the density of base stations in the terrestrial interference zone, δ denotes the fading factor (from the English, "path-loss") modeling propagation attenuation, r the radius or distance between the user equipment and the first antenna, h the height of the first antenna relative to the user equipment, (r, θ, φ) denotes the spherical coordinates of the user equipment in an O1'xyz frame centered on the server base station at ground level, θ the elevation angle between the user equipment and said first antenna, Φ the horizontal angle between the user equipment and said first antenna, A(θ, φ ) is the angular gain of the first antenna of the server base station, to which the user equipment (UE) is connected; A(θ k , φ k ) the angular gain of each of the two other antennas (k=2, 3) of the server base station, co-located with the first antenna of the server base station. H1 is the gain of each antenna in the first RT network, defined as follows by: H1(θ) dB = , where A m denotes the minimum antenna gain, and is a constant, , where φ tilt is the downward tilt angle, φ 3dBthe width of the vertical beam at half power, 9 3dB the width of the horizontal beam at half power, and is a contribution from the two other antennas (k = 2.3) of the station waitress by training.

6. A method according to any one of claims 3 to 5, characterized in that the second network being an aerial-type network comprising a plurality of satellites placed in orbit around the Earth, the determination of the second impact factor, called the satellite impact factor (SAF), is a function of a density (ρ sat ) of satellites interfering with communication in a satellite interference zone (CS defined at least according to an altitude of the satellites of the second network and a minimum elevation angle of said satellite with the user equipment.

7. A method according to the preceding claim, characterized in that the determination of a quality of service parameter value further comprises the determination of a number of interfering satellites (Nsat) for said communication in the satellite interference zone and in that the density (ρ sat ) of interfering satellites in the satellite interference zone is determined as a function of the number of interfering satellites and an area (S) of a spherical cap (CS) centered on the user equipment, of radius the orbit of the satellites of the satellite network, and delimited taking into account said minimum elevation angle.

8. A method according to the preceding claim, characterized in that the determination of the satellite impact factor (Fsat) comprises the implementation of the following equation: where ρ SAT denotes the density of interfering satellites, Rt: denotes the radius of the Earth hSAT the satellite's altitude in a coordinate system centered on the user equipment, α denotes the minimum elevation angle.

9. A method according to any one of claims 3 to 8, characterized in that the determination of a value for a parameter representative of the communication quality of service level further comprises the determination of a transmission power by the serving base station as a function of the terrestrial impact factor and at least one other associated impact factor. audit at least a second network, implementing a relationship equivalent to the following relationship: where I is an integer greater than or equal to two, denoting a number of said second networks comprising access equipment likely to interfere with said communication, Fb is the terrestrial impact factor, F i the impact factor of said second network, Pi the transmission power of each access device interferes with a said second network, G i : the gain from each access device interferes with a so-called second network, K i a propagation constant for each access device interfering with a said second network, G b : the gain from ground-based base stations, N th thermal noise, with D u the effective data reception rate by the user equipment on the downlink radio link, and W is the bandwidth used by the communication on the downlink radio link between the server base station and the user equipment. A method according to any one of the preceding claims, characterized in that the quality of service parameter belongs to a group comprising at least: - a useful data reception throughput by the user equipment; - a useful time frame for transmitting data to the user's equipment; - useful data reception power by the user equipment.

11. A method according to claims 9 and 10, characterized in that the quality of service parameter includes a useful data transmission rate (Du) and in that the useful rate (315) is derived from the expression of the transmission power (Pb) by the first base station (BS1) and determined according to the following equation:

12. A method according to claim 10, characterized in that it comprises the determination (313) of a third impact factor of a third communication network, of the drone type, as a function of a density (ρ d ) of access equipment such as drones, known as drones, interfering with the communication in a drone interference zone (CS d) defined at least as a function of an altitude of the drones of the third network and a minimum elevation angle of said drone with the user equipment and in that said determination (315) implements the following equation: Fd is the impact factor of drones in the third network on communication between the server base station and the user equipment, ρ d is the density of interfering drones, P d the transmission power of said drone interferes, G d : the gain from said drone interferes, and K d a constant in the propagation of drones.

13. A control method according to any one of the preceding claims, characterized in that said at least one modified emission characteristic belongs to a group comprising at least: - the transmission power of the server access equipment; - a gain in server equipment; - a transmission bandwidth (W) of the server equipment, - the transmission power of at least one other access device, - a gain of at least one other access device; - a transmission bandwidth (W) from at least one other access device.

14. Device (100) for monitoring a quality of service level of communication between a user device (UE) and a first wireless communication network (RT), said first network comprising a plurality of access devices (BS1, BS2, BS3) configured to transmit radio frequency beams in a given frequency band, said monitoring device being characterized in that it is configured to implement: the determination (310) of a value of a parameter representative of the quality of service level of communication between a first access device of said plurality, to which said user device is attached, said server access device (BS1), at least as a function of a bandwidth (W) allocated to this communication, of transmission characteristics of the server access device,of at least one other access device from the first network and at least one other access device from at least a second wireless communication network, (RSAT, RD, RHPA), said other access equipment being configured to emit radio frequency beams in the given frequency band and being likely to interfere with the communication, and a topology of the first network and at least one second network in at least one so-called interference zone (CS, CSd); when the determined value does not reach a target value of said parameter, the determination of a modification (34) of at least one emission characteristic of at least one antenna of said server access equipment and / or at least one other access equipment of the plurality and / or of at least one second network, depending on the target value.

15. Control device according to claim 14 characterized in that said parameter value is determined at least as a function of the bandwidth allocated to the communication, a distance between the user equipment and the server equipment, a transmission power of the server equipment, antenna gain ratios between the server equipment and said at least one other access equipment of the first network and between the server equipment and said at least one other access equipment of at least one second network, and the topology of the first network and of at least one second network in said at least one interference zone.

16. Communication system (10), characterized in that it comprises access equipment for a first network and at least a second network, said access equipment being configured to emit radio frequency beams in a given frequency band, said system further comprising a user equipment attached to said access equipment, said server access equipment, and a control device (100) according to claim 14 or 15 of a quality of service level of a communication between the server access equipment and the user equipment.

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