FR3055081A1 - POSITION CONTROL METHOD FOR A MOBILE NODE AND DEVICE THEREFOR - Google Patents

Abstract

The invention relates to a method for controlling the position of a first mobile node (100). The first mobile node may establish radio communication with a radio network, and is further configured to communicate with a position control server (40) of the first mobile node. At the first mobile node, the method proposes to measure (301, 401) a radio communication performance criterion between the first mobile node in a first position (1), and a second node (11, 12) of the radiocommunication network. . Then, a positional allocation for the first mobile node to a second position (3) is received (308, 406) from the position control server to improve the performance criterion. The invention also relates to a device configured to enable the implementation of this method.

Description

TECHNICAL AREA

The invention relates to the field of radio networks and more particularly to the optimization of radio networks by moving mobile nodes.

TECHNOLOGICAL BACKGROUND

Radiocommunication networks, in particular mobile telephone networks, are evolving in order to meet growing demands for speed and quality of service. The high data rates required to meet this growing demand from users of radiocommunication networks are pushing operators to densify the networks by adding costly infrastructure, and to allocate increasingly significant spectrum resources.

This densification, by adding base stations, and updating existing networks to enable them to operate according to new standards involves significant investments.

In order to meet the need for ever more numerous and complex infrastructures, "ad hoc" radio networks have been created. In these networks, the nodes operate autonomously without the need for centralized management infrastructure. In such networks, each node is both a user and a relay of information. However, “ad hoc” networks typically suffer from low powers and cannot by themselves meet the significant needs in terms of computing power and average speed of the mobile telephone market. This is why the "Ad-Hoc" networks have so far found more applications in the military than in the civilian field.

Another approach for densifying a radiocommunication network with a view to increasing performance in terms of speed and quality of service is proposed in document US 2015/0334768. This document uses drones which are programmed to reach a determined position allowing to offer a better radio coverage or a better quality of service between fixed nodes of a radiocommunication network. The use of mobile nodes to support ground infrastructure involves additional mobile infrastructure elements in the radio network. Adding mobile drones, and programming them to monitor the state of a network is like investing in new mobile infrastructure.

A means is therefore being sought for optimizing the operation of a radiocommunication network which is simple to implement and which does not require the installation of new expensive network infrastructures.

STATEMENT OF THE INVENTION

To respond to the problems set out above, the present invention provides a method for controlling the position of a first mobile node, the first mobile node being able to establish radio communication with a radiocommunication network, the first mobile node also being configured to communicate with a position control server of the first mobile node, the method comprising, at the first mobile node:

- measuring a radio communication performance criterion between the first mobile node being in a first position, and a second node of the radiocommunication network;

- receive, from the position control server, a position allocation for the first mobile node to a second position to improve the performance criterion.

The solutions proposed in the prior art for optimizing the operation of a radiocommunication network are based in particular on a densification of the network by the addition of new base stations or the use of radiocommunication drones. The invention uses another approach without requiring the construction of new infrastructure. To do this, the invention proposes to take advantage of the existence of at least one mobile node which can form, for example, a set of mobile nodes which are not necessarily part of the radiocommunication network, but which are located in a geographic area close to or within radio coverage of the radiocommunication network. The term "radio coverage" refers to the space in which the range of radio signals enables radio communication to be established with a node in the radiocommunication network. The mobile node is considered in the present invention as a radio resource usable by the radiocommunication network under certain conditions of proximity with fixed or mobile infrastructures of the radiocommunication network, that is to say, when a radio communication can be established with the network. The mobile node is therefore not necessarily permanently active within the network, but can be added to the network to densify it or exploit it for its own needs.

The first mobile node receives position setpoints from a position control server. The first mobile node is diverted from its primary function within the set of mobile nodes to be grafted onto the radiocommunication network, thus becoming a fully-fledged mobile node of this network. The first mobile node is then able to exploit the resources of the network for itself and reinforce the network by providing it with its own radio resources in reception / transmission. More particularly, the mobile node can be an autonomous electric vehicle which receives position instructions from a control center, materialized by the position control server. This mobile node is able to communicate with the infrastructures and nodes of the radiocommunication network and adapts its position to fulfill the function of mobile node within the radiocommunication network.

In other words, the first mobile node can belong to a set of mobile nodes each typically having the function of reaching a target destination assigned to them. This target destination can be assigned by a user directly or via the position control server of the mobile nodes. The first mobile node also belongs, within the framework of the method described above, to a radiocommunication network, in particular when its position allows it to enter into radio communication with nodes of this network. The first mobile node can then adapt its position, despite its initial displacement setpoint, in order to increase a criterion of communication performance of the radiocommunication network. It can for example be an autonomous electric vehicle, which slightly modifies its initial route to improve the functioning of the radiocommunication network. However, the first mobile node may not abandon its initial mission of movement to the target destination. The first mobile node is then temporarily in the service of the radiocommunication network or else user of the resources of this network. It can be replaced by another mobile node when the location of the first mobile node is no longer compatible with its initial setpoint. The first mobile node may also not be in displacement when it is requested to reinforce the resources of the radiocommunication network, in which case its displacement towards the second position is not made to the detriment of a displacement towards an initial target destination . This can occur, for example, in the case of a vehicle parked at a first initial position which is brought to park at a second position for the needs of the network or for better access to network resources.

The first mobile node measures a performance criterion for communication with a second node in communication with the radiocommunication network. This second node can be a mobile node of the set of mobile nodes exchanging radio information with the radiocommunication network and thus forming an integral part of this network or any other node of the radiocommunication network, for example.

According to one embodiment, the method can also comprise:

- transmit, from the first mobile node, a request for allocation of new position to the position control server based on the measurement of the performance criterion.

Reception of the position allocation may include:

- receive the second position allowance in response to the request for a new position.

In this embodiment, the first mobile node actively requires a new position enabling it to optimize a performance criterion within the radiocommunication network. The first mobile node thus seeks to benefit from the radio resources of the radiocommunication network in order to meet a specific need. For example, the first mobile node can be an electric vehicle with a terminal on board seeking to access a wireless network. The vehicle can then adapt its route in order to offer an optimized service at the terminal.

The method can in particular comprise:

- request from the first mobile node the establishment of a service with the radiocommunication network;

- generate the request for allocation of a new position on receipt of a refusal to establish the service.

When the resources of the radiocommunication network do not allow a sufficiently robust radio communication to be established with the first mobile node, the first mobile node may require a position which allows suitable communication with the radiocommunication network.

According to one embodiment, the method can also comprise:

- Providing, from the first mobile node, the measurement of the performance criterion to the position control server;

- receive a position control command to move the first mobile node to the second position.

According to this alternative embodiment, the first mobile node does not seek to adapt its position in order to satisfy its own needs by taking advantage of the resources of the radiocommunication network. By providing the performance criterion measurement to the position control server, the first mobile node makes itself available to reposition itself in order to optimize, even temporarily, the resources of the radiocommunication network. The first mobile node then acts as a network node offering additional radio links to the latter, increasing the performance criterion in a geographical area. This geographic area can in particular meet a criterion of compatibility with the target destination of the mobile node when its repositioning in the second position deviates it from its trajectory towards this target destination.

According to one embodiment, the first mobile node may belong to a set of mobile nodes, each mobile node being able to establish radio communication with a radiocommunication network, and configured to communicate with the position control server of the mobile nodes, the method which can also comprise:

- measures a performance criterion in a third mobile node located in a third position;

- interrupt the radio communication between the first mobile node and the radiocommunication network and initiate radio communication with the third mobile node, when the allocation of the second position to the first mobile node no longer makes it possible to obtain a desired performance criterion.

The method of the present invention is based on the fact that the mobile nodes of the set of mobile nodes are undifferentiated. Indeed, their primary function is not to be an integral part of the radiocommunication network, but to reach a target destination. Thus, when the movement of the first mobile node moves it away from the area of the network in which it offers and uses radio resources, and the first mobile node is no longer able to provide for the needs of the radiocommunication network, it can be replaced by another mobile node in the vicinity and within the radio coverage range of a node in the radiocommunication network. More particularly, the first mobile node can be replaced by another mobile node when the second position allocated to the first mobile node no longer makes it possible to obtain a desired performance criterion and when the third mobile node allows to obtain the desired performance criterion .

Advantageously, the performance criterion can relate to a quality of communication between the first mobile node and another node in communication with the radiocommunication network or a radio coverage provided by the first mobile node.

The term "radio coverage" here refers to the geographic area around a node or set of nodes within which communication by radio waves with the radiocommunication network can be established. The performance criterion can therefore be a measure of the extent of the range of any signal passing through the radiocommunication network. The first mobile node then moves in order to extend the radio coverage of the radiocommunication network, for example by offering a service in an area not yet accessible via the radiocommunication network or by providing assistance to a defective node or set of nodes of the radio network. Alternatively, the performance criterion may relate to a parameter representative of the quality of service of the radiocommunication network.

In particular, the performance criterion can be chosen from: a radio link power, a data rate, a data packet loss rate, an indicator of a number of links ΜΙΜΟ.

These various parameters make it possible to provide quantitative information on the robustness of the radiocommunication network in the vicinity of the first mobile node, for example an indication of the level of obstruction of communications within the network. The number of links ΜΙΜΟ (for “multi-input multi-output” according to English terminology) is representative of the environment in the vicinity of the node, which can present obstacles likely to reduce the quality of the radio signal (buildings, vegetation, reliefs for example). The rate of data packet loss and the strength of the radio link are also parameters representative of the robustness of the network. The data rate, as well as the power of the radio link between nodes are representative of the network's capacity to transmit information at a high rate. The first mobile node can then adapt its position in order to increase the bandwidth in the radiocommunication network in the vicinity of the first mobile node.

According to one embodiment, the method can also comprise:

- determine the second position from a map of measurements or previous estimates of performance criteria in different positions.

The choice of the second position for the first mobile node, making it possible to increase the value of the performance criterion, is made on the basis of values estimated and measured previously, accessible via field maps. These cards can also be derived from or supplemented by simulations determining the expected or expected values of the electromagnetic field attributable to signals from a radiocommunication network.

In particular, the method can also comprise:

- memorize the measurement of the performance criterion and map values of performance criteria as a function of the position of the first mobile node.

The first mobile node can update existing maps of performance criteria, or even constitute such maps, by storing the performance criterion measured at different locations during the movement of the first mobile node to reach its target destination.

According to one embodiment, the method can also comprise:

- estimate a performance gain in the radiocommunication network and / or a cost resulting from a move from the first mobile node to the second position,

- move the first mobile node to the second position according to the gain and / or cost estimates.

The first mobile node may have the primary function of reaching a target destination assigned to it by a user or via the location management server. Moving the first mobile node can cause it to change its route so as to extend its route to reach this target destination. It is then necessary to determine whether the assistance provided by the first mobile node to the radiocommunication network or the benefit which the first mobile node derives from entering into communication with the radiocommunication network are relevant in relation to the additional cost linked to this additional movement. It is possible to refuse the movement of the first mobile node to the second position when this movement involves an additional cost in energy and / or distance and / or time greater than a predefined threshold. It is also possible to compare the expenses linked to this additional trip with an amount which can be invoiced for the service rendered by the first mobile node vis-à-vis the radiocommunication network. The trip is made when the expense is less than or equal to the gain withdrawn by the billable amount, for example. It is also possible to refuse travel when the additional cost it generates is not offset by a satisfactory performance gain (for example, if the performance criterion in the second position is less than a threshold tolerance value). This measurement of the performance gain compared to the cost can be carried out even when the first mobile node is not initially intended to reach a target destination, for example in the case where the node is a parked electric vehicle to which is assigned a new parking space located in a second position.

According to one embodiment, the radiocommunication network is a hierarchical network comprising nodes using different communication protocols, the method further comprising:

- establishing radio communication between the first mobile node and nodes using different communication protocols, the first mobile node fulfilling the gateway function in the hierarchical network.

Operating in gateway mode between nodes using different communication protocols allows the first mobile node to interface with different radiocommunication infrastructures. One can for example consider a mobile node acting as a gateway between base stations on the ground of a mobile telephone network, or wifi, and satellite antennas, there are many radio-relay systems. The first mobile node acts as a mobile gateway between two different communication technologies.

According to one embodiment, the radiocommunication network can comprise a set of nodes forming an ad hoc network, the method further comprising:

- establish radio communication between the first mobile node and nodes of the ad hoc network using an ad hoc routing protocol.

The radiocommunication network can also be a hybrid network comprising both nodes communicating according to an “ad hoc” routing protocol and nodes forming a hierarchical subgroup, communicating via gateways comprising for example the first mobile node or 'other nodes.

The method can also comprise:

detect network infrastructures and communication protocol stacks associated with said network infrastructures in the vicinity of the first mobile node, the neighborhood comprising network infrastructures capable of being in direct radiocommunication with the first mobile node,

- obtain the position and the communication protocol stacks of the detected network infrastructures.

The invention also relates to a device configured to communicate with a radiocommunication network and a position control server of a set of mobile nodes, the device being configured to implement the method described above.

Advantageously, the device can be embedded in an electric vehicle.

The invention also relates to a computer program product comprising a series of instructions stored on a storage medium for execution by a computer or a dedicated device, said program being configured to execute the method described above.

DESCRIPTION OF THE FIGURES

The process which is the subject of the invention will be better understood on reading the following description of exemplary embodiments presented by way of illustration, in no way limiting, and by observing the drawings below in which:

- Figures 1 and 2 are schematic representations of a mobile node modifying its initial path in order to reach a second position increasing a performance criterion in a radiocommunication network;

- Figure 3 is a sequence diagram illustrating steps of a method of controlling the position of a mobile node according to a first embodiment of the invention;

- Figure 4 is a sequence diagram illustrating steps of a position control method of a mobile node according to a second embodiment of the invention;

- Figure 5 is a schematic representation of a mobile node whose position is controlled according to the method of the invention, establishing connections between several radiocommunication networks,

- Figure 6 is a schematic representation of a computer system for operating a computer program product implementing the method of the invention.

For reasons of clarity, the dimensions of the different elements shown in these figures are not necessarily in proportion to their actual dimensions. In the figures, identical references correspond to identical elements.

DETAILED DESCRIPTION

The present invention provides a method for optimizing the performance of a radiocommunication network by moving a mobile node. More particularly, the invention proposes to take advantage of the presence of at least one mobile node located in an area allowing it to enter into radio communication with the radiocommunication network. The mobile node integrates, at least temporarily, the radiocommunication network and exchanges data by radio signals with the other infrastructures of the radiocommunication network. The mobile node can thus use the radio resources of the radiocommunication network in order to meet the needs of a terminal which may be located in or on the mobile node. The mobile node can also densify, at least temporarily, the radiocommunication network by operating as a fully-fledged node, offering additional radio links, within the network.

FIG. 1 schematically represents a first mobile node 100 intended to perform a path 101 between a first position 1 and a target destination 2. This first mobile node 100 is configured to communicate with a position control server of the mobile node. This position control server typically allocates a displacement instruction to the first mobile node 100. This displacement instruction can for example manifest itself in the form of the allocation of a new position. The first mobile node 100 then moves along a path, determined by the mobile node or proposed by the position control server, to reach the target destination 2. Alternatively, the first mobile node 100 can also be stopped in a first position 1. In this case, the allocation of a second position 3 can also correspond to a position of the first mobile node when stopped. This situation can typically correspond to a vehicle which changes parking in the context of the present invention.

As illustrated in FIG. 1, the first mobile node is located in the vicinity of two nodes 11, 12 of a radiocommunication network. These two nodes 11, 12 respectively have radio coverage areas 21, 22, which do not overlap. In other words, as shown in Figure 1, no radio signal can pass directly between nodes 11 and 12.

The lack of radio coverage between these two nodes can adversely affect the performance of the radio network in this geographic area. The method of the present invention makes it possible to remedy this by carrying out a measurement, by the first mobile node 100, of a performance criterion of a radio communication between the first mobile node 100 and a node of the radiocommunication network. This measurement is carried out in FIG. 1 between the first mobile node 100 and the node 11 of the network. This measurement is possible because the radio coverage 23 of the first mobile node 100 partially overlaps the radio coverage area 21 of the node 11. The measurement of the performance criterion is supplied to the radiocommunication network, which then makes it possible to implement a strategy of movement of the first mobile node 100, adapted to the needs of the first mobile node 100 and of the radiocommunication network.

The invention then proposes to assign a new position to the first mobile node 100, so that in this new position the performance of the radiocommunication network is improved. The first mobile node 100 is integrated at least temporarily into the radiocommunication network. The relevance of this relocation of the first mobile node lies in the fact that the first mobile node 100 is fortuitously located in the vicinity of the radiocommunication network, in an area of the network suffering from poor performance. Insofar as the first mobile node is equipped to enter into radio communication with the radiocommunication network, it can improve the performance of the network by moving to the second position 3, without however deviating considerably from its initial path in the direction of its target destination 2. The first mobile node is then temporarily placed at the service of the network, and can also benefit from network resources to meet its own needs. The second position 3 is typically allocated to the first mobile node 100 by the position control server.

The displacement of the first mobile node towards the second position 3 implies a slight modification of the path followed by the first mobile node. The new path 102 is thus extended relative to the initial path 101. As illustrated in FIG. 2, when the first mobile node 100 is located in the second position 3, better quality radio communication can be obtained due to overlap radio coverage areas 21 and 23 as well as radio coverage areas 23 and 22.

It should be noted that the first mobile node 100 can remain in the second position 23 for a certain time, or else continue its route along the path 102 to reach the target destination 2. It is also possible that the first mobile node 100 doesn ' has no target destination 2, in which case its movement from the first position 1 to the second position 3 allows the first mobile node 100 to remain in the second position 3 indefinitely, until a new position setpoint is assigned to it .

In the representations of FIGS. 1 and 2, the displacement of the first mobile node makes it possible to increase the radio coverage of the network. Thus, the performance criterion measured between the first mobile node 100 and the node 11 is a geographic parameter, linked to the range of the radio signals exchanged between these two nodes. However, other performance criteria for the radio network can be measured. It is for example possible to measure a radio link power, a data rate, a data packet loss rate or an indicator of a number of links ΜΙΜΟ between the first mobile node and a node of the radiocommunication network. These various parameters are representative of a quality of radio link between the first mobile node 100 and a node of the radiocommunication network.

It is possible to group these different parameters into three categories: a measurement of radio coverage, a measurement of the robustness of the network and a measurement of the network capacity.

The radio coverage is representative of the geographical area in which radio signals can be exchanged via the radiocommunication network. Optimizing radio coverage involves expanding this area when moving the first mobile node 100, taking into account the maximum ranges of radio signals transmitted and received by the first mobile node.

The robustness of the radiocommunication network is representative of the quality of the radio transmission between nodes of the network, in particular the rate of errors in the transmitted data packets, and the interference, losses of intensity or delays in the transmission which can result from the presence of physical obstacles in the path of the signals passing between nodes of the network. The number of links ΜΙΜΟ (“multi-input, multi-output” according to English terminology) is an indicator of these physical obstacles in the network. The performance criterion measured can for example be a value representative of the decorrelation of the different radio signal propagation paths, such as for example the rank of the correlation matrix of the system ΜΙΜΟ as described in the known prior art. The strength of the radio link, that is, the strength of the radio signals exchanged, as well as the rate of data packet loss, are also indicators of the robustness of the network. Optimizing the robustness of the network by means of the first mobile node 100 thus makes it possible to increase the number of links ΜΙΜΟ, by relaying radio signals by the first mobile node 100. In doing so, the radio signals can bypass an obstacle blocking or reducing the quality of the radio signals transmitted in this geographical area of the radiocommunication network.

The capacity of the radiocommunication network is representative of the data rate exchanged via the network. The displacement of the first mobile node 100 to the second position 3 then makes it possible to add additional radio links in the network locally increasing the bandwidth in the network.

Figures 3 and 4 show two complementary embodiments of the method according to the invention.

FIG. 3 schematically illustrates on a sequence diagram different steps occurring when a terminal 101 located in or on the first mobile node 100 requests access to the radio resources of a radiocommunication network. To do this, the first mobile node 100 submits a repositioning request in order to optimize the radio resources accessible from the terminal. For example, it could be a user looking to access the internet or a 4G, 5G network from a moving vehicle. The vehicle can then determine a new position in which the network accessible from the terminal offers such performance with one or the best connection, without however deviating excessively from its initial trajectory.

Throughout the process of the invention, the position of the first mobile node 100 is transmitted to the position control server 40, which is represented by the arrow 300 in FIG. 3. This position can be known via GPS measurements or well by other known means, for example by estimating the position of the mobile node on the basis of vector information and speed of movement from an initial position.

The first mobile node comprises a terminal 101, which can be put into radio communication with the radiocommunication network and means 102 for communication with the position control server 40 and the network. The radiocommunication network can be a hierarchical network, an “ad hoc” network or a hybrid network. It can be a 3G network of UMTS type (for “universal mobile telecommunication System” according to English terminology), a 4G network of LTE type (for “Long-term evolution” according to Anglo-Saxon terminology) or any other type of radio network. In FIG. 3, a 3G network is shown, with a radio access network 20 (“access network” according to English terminology), and a core network 30 (“core network” according to English terminology) . The distinction in what follows between "radio access network" 20 and "core network" 30 is more a logical separation than a physical one and can be applied regardless of the type of mobile networks envisaged. For example, in the UTRAN architecture of 3G (for "Universal Terrestrial Radio Access network" according to English terminology), the access network typically includes base stations and the base station controller (RNC for " Radio Network Controlling ”according to English terminology), and the core network splitting into two very distinct entities: the“ circuit ”and the“ packet ”. In the E-UTRAN architecture (evolved UTRAN according to Anglo-Saxon terminology) of 4G, the radio access network, in charge in particular of managing mobility and radio resources, is limited to base stations (NodeB ), the core network part (EPC "Evolved Packet Core" according to English terminology) located in various servers ("Gateway" according to English terminology) managing the establishment of sessions, security, location of mobiles in the network.

Furthermore, it is very clear that the position server which transmits its position instructions to autonomous vehicles (see arrows 307, 308, 406 below) is an entity independent of the mobile communications network and the information which is transmitted is transmitted by the upper application layers of the communications network in the network user plane (“User-Plane” according to English terminology). Nothing, however, excludes according to the invention, and according to the possible degrees of coupling between the economic entities which manage the communication network and those which manage the position network of vehicles, from considering a transmission of this information by the plan signaling of the communication network (“control plane” according to English terminology).

The measurement 301 of the performance criterion is communicated to the radio access network 20. The measurement can be relayed by the radio access network 20 at the heart of the network 30 as indicated by step 3011 in FIG. 2. A radio connection is established between the first mobile node 100 and the radio access network 20, as represented by step 302. The first mobile node, via its terminal 101, then requests access to the radio resources of the radiocommunication network to respond to its needs, in step 303. This service request can be transmitted directly to the heart of the network 30 as shown in FIG. 3, or sent to the radio access network 20 and then be relayed by the radio access network 20 at the heart of the network 30. This request can be relayed using an SCCP protocol (for “signal connection control part” according to English terminology) for example. To access the request from the first mobile node, the core network 30 sends a request for physical resources to the radio access network 20, in step 304.

As shown in FIG. 3, this request for physical resources can be refused by the radio access network 20, when the latter is unable to respond to the request from the first mobile node 100. The allocation of resources can be refused due to a simple physical impossibility of allocating these resources, for example when the requested physical resources are not available. This allowance can also be refused because it would have negative consequences for the functioning of the network. FIG. 3 illustrates a refusal to allocate resources by the arrow 305 marked with a cross.

To remedy this refusal, the radio access network 20 sends the first mobile node 100 an invitation to move to a better position in step 306. This request for a better position reaches the means 102 of communication with the control server. positions and the network, which then sends a new position request to the position control server 40 in step 307.

The position control server 40 then determines a second position 3 which will allow the first mobile node 100 to access the physical resources which it needs within the radiocommunication network.

To determine this second position 3, the position control server can for example estimate the quality of the radio link or the radio coverage area from which the first mobile node 100 could benefit in various positions on the basis of preexisting maps of criteria criteria. performance. These measurements can have been carried out beforehand by other mobile nodes, or else acquired progressively by the first mobile node 100. Such information on the previous measurements of performance criteria can be accumulated as and when displacements of the first mobile node. The expected performance criterion can also be estimated by calculations on the basis of any other relevant information, for example the topology of the terrain, the presence of obstacles, previous measurements of the intensity of radio signals obtained at various points in the network.

Once a second position making it possible to optimize the transfer of information between the terminal 101 and the radiocommunication network is determined, the position control server 40 allocates a second position 3 to the first mobile node 100 in step 308 The first mobile node 100 then moves to the second position 3. A continuous measurement of the performance criterion makes it possible to verify that the necessary physical resources will indeed be available in this new position.

The means 102 of communication with the position control server and the network communicate the new position of the first mobile node to the radio access network 20 which confirms the allocation of physical resources in step 309.

The physical resources are then allocated to the terminal 101 by the radio access network 20 in step 310 and the transfer of radio data between the terminal 101 of the first mobile node 100 and the core network 30 becomes effective in step 311 .

In this first embodiment illustrated in the sequence diagram of FIG. 3, the first mobile node 100 requires on its own the use of the resources of the radiocommunication network. However, the invention also provides another embodiment, which can be operated as an alternative to the first embodiment or in addition to the latter.

This second embodiment is illustrated in the sequence diagram in FIG. 4. The position of the first mobile node 100 is known to the position control server 40 by means similar to those described above.

A radio communication performance criterion between the first mobile node 100 and another node of the radiocommunication network is measured in step 401. The communication to the radio access network 20 of the measurement of the performance criterion allows the radiocommunication network to be alerted of the presence of a first mobile node capable of strengthening the radiocommunication network to increase its radio coverage, its robustness or its capacity. As indicated in FIG. 3, the measurement of the performance criterion can also be relayed to the heart of the network 30 (step 4011).

Alternatively, or in addition, the measurement of the performance criterion can be communicated directly to the position control server 40.

This communication of the performance criterion measurement can be carried out in real time or discontinuously, at regular intervals or not. The radio access network 20 which manages the performance criterion measurements made by the first mobile node and the infrastructures of the radiocommunication network can inform the position control server 40 of the content of its performance criterion measurement databases. , which allows the latter to maintain or improve a correspondence between the position and the performance criterion.

In other embodiments, it is possible to communicate the measurement of the performance criterion to the position control server directly or by relaying the measurement throughout the process of the invention.

In step 402, the core of the network 30 makes a request to allocate physical resources to the radio access network. This request can be generated by a network user who seeks to access a service that is not accessible to him in the current operation of the radiocommunication network.

The radio access network 20 determines whether such allocation of resources is possible.

In the example of FIG. 4, such an allocation of resources is not possible and the radio access network 20 sends to the core network 30 a refusal to allocate resources in step 403.

Following this refusal, the core of the network 30 sends to the position control server 40 in step 404 a request for assistance. This request can for example include information relating to the nature and characteristics of the physical resources that the core of the network 30 seeks to obtain (increase in radio coverage, increase in the robustness or in the capacity of the network for example).

At the same time, insofar as it has been verified that the first mobile node can meet the needs of the radiocommunication network by repositioning the first mobile node, a radio connection can be established between the first mobile node (its terminal 101 or even the means 102 for communication with the position control server and the network) and the radio access network 20. This connection can for example be established in step 405.

The position control server 40 then determines a second position 3 making it possible to meet the needs of the radiocommunication network and allocates this second position 3 to the first mobile node 100 in step 406.

In the embodiment represented in FIG. 4, contrary to the scenario represented in FIG. 3, it is the position control server 40 which takes the initiative to propose a new position, without being invited to do so by the first mobile node 100. This new position is based on a priori knowledge by the position control server 40 of the quality of service / position correspondence of the first mobile node for a given communication scenario between at least one node of the radiocommunication network and the first node mobile.

The steps 310 and 311 of allocation of physical resources and of data transfer are then implemented in a similar manner to that which has been described in relation to the first embodiment of FIG. 3.

These two embodiments make it possible to densify a radiocommunication network by adding to this network a first mobile node. Thus, it is no longer necessary to resort to the installation of additional fixed or mobile infrastructures to densify a radiocommunication network or repair faulty installations. The invention makes it possible to temporarily include in the radiocommunication network an element external to this network, which is mobile and can be placed at a strategic location in order to efficiently use the resources of the network for its own needs or to come to densify the radio network.

The first mobile node 100 can be an autonomous electric vehicle. Such vehicles generally have a powerful battery capable of supplying electricity to the means of emission and transmission of radio waves.

The first mobile node 100 is described above as performing a movement between a first position 1 and a target destination 2. In the case of an autonomous electric vehicle, the vehicle can be controlled either by a position control server 40, or by piloting infrastructures for autonomous electric vehicles arranged near the roads. The destination instructions can also be relayed from the position control server, from the piloting infrastructures or even be at least partially relayed by the radiocommunication network.

As described above, the movement of the first mobile node 100 can deviate the latter from an optimal trajectory followed to reach a target destination 2.

When a second position allocation 3 is made, the first mobile node can decide not to make the movement when this movement is not sufficiently profitable. The choice to refuse such a movement can also be made by the position control server, which then decides not to allocate a new position to the first mobile node.

To determine whether a first mobile node should be repositioned in order to optimize a radiocommunication network, it is necessary to determine the expected gain on the performance of the radiocommunication network and compare it to the additional cost induced by the displacement of the first mobile node. Indeed, any movement of the first mobile node implies a cost in energy and travel time. If the gain in performance in the radiocommunication network does not sufficiently compensate for the efforts invested in moving the first mobile node, it is possible to refuse the move.

For example, when the movement aims to provide better radio coverage, by offering an otherwise inaccessible radio service, the movement of the first mobile node can be carried out regardless of the cost associated with the movement. When moving the first mobile node only increases the speed or quality of the radio link, the cost of moving can be taken into account. The first mobile node 100 can then only be moved if the service associated with the increase in speed or with the better quality of the radio link can be billed and compensate for the additional cost linked to the movement of the first mobile node. Added travel time and additional cost thresholds can also be set to frame this type of choice.

The method described above only refers to a single mobile node. However, the contribution of a set of mobile nodes, for example a fleet of autonomous electric vehicles, is considerable for a radiocommunication network. In the presence of a set of mobile nodes, the method of the invention can select the mobile node closest to an area of the radiocommunication network requiring densification or repair. In addition, a mobile node which only remains temporarily in the vicinity of the second position 3 can be replaced by another mobile node located nearby when the path to the target destination 2 moves it away from its second position 3. Thus, from close in close proximity, the mobile nodes can be used transiently to support the radiocommunication network and to densify it, in a dynamic process.

FIG. 5 schematically represents the role which a first mobile node 100 can fulfill to optimize the operation of a radiocommunication network according to the method of the present invention. The radiocommunication network notably comprises the core network 30 shown in FIG. 5 near the position control server 40.

The first mobile node 100 is an autonomous electric vehicle acting as a gateway between several networks. A first hierarchical network 110 includes base stations 8 in radio link with terminals 5 and possibly a set of satellite antennas 6 in radio communication 501 with satellites 7. The first mobile node 110 is able to be in radio communication with the satellites 7, base stations 8 and terminals 5. The radio network 200 exchanges radio signals 503 with the first mobile node 100.

The first mobile node 100 is also in radio communication with an “ad hoc” network 120 comprising various terminals 5 and other mobile nodes 101. The first mobile node acts in FIG. 5 as a gateway capable of transcoding signals from the hierarchical network 110 to the “ad hoc” network 120 and vice versa. The gateway function allows the first mobile node to put radio subgroups of nodes that cannot otherwise communicate with each other, and exchanging data according to different communication protocols. The first mobile node 100 then acts as an interface between several networks, thus effectively densifying a radiocommunication network by the merger of several independent networks.

The position control server exchanges information via a channel 502 with the available mobile nodes. Control infrastructures 4 for the mobile nodes are also shown in FIG. 5.

The first mobile node 100 can be used as a gateway carrying out a link between several different types of radiocommunication networks. The first mobile node can also evolve within a non-hierarchical "ad hoc" network and not fulfill the role of gateway. The first mobile node can also act as a hub in the radio network.

Several additional possibilities are possible to allow the first mobile node to enter into communication with radio networks of which it is not previously aware. For example, it is possible to provide for the detection by the first mobile node 100, of infrastructures specific to a new radiocommunication network within the range of its radio coverage. These network infrastructures can then relay their communication protocol stacks to the first mobile node. The first mobile node thus obtains the elements enabling it to enter into radio communication with these infrastructures in order to implement the method described above.

The first mobile node can also be able to receive satellite signals and optimize its positioning to receive and broadcast the satellite signals as best as possible and rebroadcast them to a terrestrial radiocommunication network.

The first mobile node can also carry a terrestrial antenna and move in order to align itself in the transmission lobe of a radio beam to constitute a reception station relaying the data to other network infrastructures on the ground.

The invention also relates to a device configured to communicate with a radiocommunication network and a position control server 40, the device being configured to implement the method described above. This device can for example comprise means for transmitting and receiving radio signals, a battery supplying these means and coding, transcoding and communication tools according to various protocols, and can be carried on an autonomous electric vehicle.

The invention also relates to a computer program product comprising a series of instructions stored on a storage medium for execution by a computer or a dedicated device, the program being configured to execute the method described above.

FIG. 6 represents an example of a computer system making it possible to operate a computer program product comprising instructions implementing the method of the present invention.

In this embodiment, the device comprises a computer 600, comprising a memory 605 for storing instructions allowing the implementation of the method, the measurement data received, and temporary data for carrying out the various steps of the method as described above. .

The computer also has a circuit 604. This circuit can be, for example:

a processor capable of interpreting instructions in the form of a computer program, or

- an electronic card, the steps of the process of the invention are described in silicon, or

- a programmable electronic chip like an FPGA chip (for “FieldProgrammable Gâte Array” in English).

This computer has an input interface 603 for the reception of measurement data, and an output interface 606 for the supply of commands controlling the evacuation device 607. Finally, the computer may include, to allow easy interaction with a user, a screen 601 and a keyboard 602. Of course, the keyboard is optional, in particular within the framework of a computer having the shape of a tactile tablet, for example.

Claims (16)

Claims 1. Method for controlling the position of a first mobile node (100), the first mobile node being able to establish radio communication with a radiocommunication network, the first mobile node being further configured to communicate with a control server. positions (40) of the first mobile node, the method comprising, at the first mobile node: - measuring (301, 401) a radio communication performance criterion between the first mobile node located in a first position (1), and a second node (11, 12) of the radiocommunication network; - receiving (308, 406), from the position control server, a position allocation for the first mobile node to a second position (3) to improve the performance criterion. 2. Method according to claim 1, further comprising: - transmit (307), from the first mobile node, a request for allocation of new position to the position control server based on the measurement of the performance criterion; and in which the reception of the position allocation includes: - receive (308) the second position allowance in response to the request for a new position. 3. Method according to claim 2, further comprising: - request (303) from the first mobile node the establishment of a service with the radiocommunication network; - generate the request for allocation of a new position on receipt of a refusal (305) to establish the service. 4. Method according to any one of claims 1 to 3, further comprising: - Providing, from the first mobile node, the measurement of the performance criterion to the position control server; - receiving (406) a position control command to move the first movable node to the second position. 5. Method according to any one of claims 1 to 4, wherein the first mobile node belongs to a set of mobile nodes, each mobile node being able to establish radio communication with a network of 5 radio communication, and configured to communicate with the position control server of the mobile nodes further comprising: - measure a performance criterion in a third mobile node located in a third position; - interrupt the radio communication between the first mobile node and the network 10 radio communication and initiate radio communication with the third mobile node, when the allocation of the second position to the first mobile node no longer makes it possible to obtain a desired performance criterion. 6. Method according to any one of claims 1 to 5, wherein the criterion of 15 performance relates to a quality of communication between the first mobile node and another node in communication with the radiocommunication network or radio coverage provided by the first mobile node. 7. The method of claim 6 wherein the performance criterion is chosen 20 of: radio link power, data rate, data packet loss rate, indicator of number of links ΜΙΜΟ. 8. Method according to any one of claims 1 to 7, further comprising: - determine the second position from a measurement or estimate map 25 previous performance criteria in different positions. 9. Method according to any one of claims 1 to 8, further comprising: - memorize the measurement of the performance criterion and map values of performance criteria as a function of the position of the first mobile node. 10. Method according to any one of claims 1 to 9, further comprising: - estimate a performance gain in the radiocommunication network and / or a cost resulting from a move from the first mobile node to the second position, - move the first mobile node to the second position according to the gain and / or cost estimates. 11. Method according to any one of claims 1 to 10, in which the network of 5 radiocommunication is a hierarchical network comprising nodes using different communication protocols, the method further comprising: - establishing radio communication between the first mobile node and nodes using different communication protocols, the first mobile node fulfilling the gateway function in the hierarchical network. 12. Method according to any one of claims 1 to 11, in which the radiocommunication network comprises a set of nodes forming an ad hoc network, the method further comprising: - establish radio communication between the first mobile node and nodes of the 15 ad hoc network using an ad hoc routing protocol. 13. Method according to any one of claims 1 to 12, further comprising: - detect network infrastructures and communication protocol stacks associated with said network infrastructures in the vicinity of the first node 20 mobile, the neighborhood comprising network infrastructures able to be in direct radiocommunication with the first mobile node, - obtain the position and the communication protocol stacks of the detected network infrastructures. 25 14. Device configured to communicate with a radiocommunication network and a position control server of a set of mobile nodes, the device being configured to implement the method of any one of claims 1 to 13. 30 15. Device according to claim 14, on board an electric vehicle. 16. A computer program product comprising a series of instructions stored on a storage medium for execution by a computer or a dedicated device, said program being configured to execute the method according to any one of claims 1 to 13. 1/6