EP4316198A1

EP4316198A1 - Method for controlling a multi-hop transmission in a wireless communication network, method for processing a multi-hop transmission, corresponding devices, system and computer programs

Info

Publication number: EP4316198A1
Application number: EP22717859.7A
Authority: EP
Inventors: Jean-Marc Kelif
Original assignee: Orange SA
Current assignee: Orange SA
Priority date: 2021-03-26
Filing date: 2022-03-25
Publication date: 2024-02-07
Also published as: CN117063606A; FR3121305A1; WO2022200746A1

Abstract

The invention relates to a method for controlling a multi-hop transmission in a wireless communication network, said transmission implementing a plurality of relay nodes of a wireless communication network, the method being characterised in that it comprises: obtaining (30), for said current relay node (Ri), a current strength ratio (PINRi) between a strength of the radio signal and a noise and interference strength, received and measured by said current relay node; determining (31) a current intermediate transmission delay (DTi) of a volume of data transmitted by a source node participating in the multi-hop transmission, between said source node or the preceding relay node and said current relay node, said current intermediate transmission delay (DTi) being a function of said obtained current strength ratio, a received data volume and a transmission bandwidth (between the source node or the preceding relay node and said current relay node); estimating (32) an overall transmission delay (DTGN) of said data volume from the source node to a final relay node placed at a number N of hops, where N is an integer greater than or equal to i, at least on the basis of the determined current intermediate transmission delay (DTi) and at least one previously determined intermediate delay; and, if the estimated overall transmission delay reaches or exceeds a given maximum delay (DMax), modifying (34) a multi-hop transmission configuration of said system.

Description

DESCRIPTION

TITLE: Method for controlling a multi-hop transmission in a wireless communication network, method for processing a multi-hop transmission, devices, system and corresponding computer programs.

Technical field of the invention

The field of the invention is that of a wireless communication network, for example of the cellular type, comprising a plurality of relay equipment configured to receive a radio signal carrying a volume of payload data transmitted by a source equipment in said network , amplify it and relay it in whole or in part, or even complete it.

In particular, the invention relates to the control of a maximum transmission delay of such a volume of data in said network.

Prior art

A wireless communication network is known, for example of the cellular radio type, in which a source equipment, for example a mobile terminal, for example on board a vehicle, emits a radio signal and this signal is relayed by several relay equipment of the type “Amplify and Forward” before reaching its destination. We also speak of multi-hop transmission (for “multi-hop”, in English), each hop designating the reception, amplification and retransmission of the radio signal by a relay device. Note that the destination of the radio signal transmitted by the source equipment is not necessarily known in advance by the source equipment, the radio signal can indeed be transmitted to a particular equipment, but it can also be sent to one or more devices, for example devices verifying a predetermined condition such as being located at a number of hops from the source device less than or equal to a determined number or within a given geographical radius.

Such relay equipment is configured to amplify the total power of the signal received before retransmitting it to a following relay equipment. Thus the power received by the destination equipment is composed of that of the useful signal emitted by the source equipment and of a non-useful power due to the interference suffered by the signal at each jump and to the undifferentiated amplification of the interference and of the signal. useful performed by each relay device. This interference comes from all the network equipment transmitting at the same frequency as the transmitted signal.

A use case of multi-hop transmissions concerns motorized vehicles, for example cars, which drive in file on a road. The first car transmits information carried by a radio signal to the one following it. For example, it is information relating to the control of the vehicle, such as information relating to a braking command or a change of direction. The second car exploits, if appropriate, the on-board command in the radio signal it has received, re-amplifies it and retransmits it to the next car in line, and so on.

In this case of use, we do not necessarily know a priori the maximum number of possible cars capable of receiving and retransmitting the signal.

However, it may be that the information emitted by the source equipment and conveyed by the radio signal has a limited period of validity: for example, it is possible to envisage that information relating to the control of a vehicle which is traveling on a road such as A braking command become obsolete after a few seconds or at the end of the event having triggered the control of the vehicle, such as in particular when a traffic jam having triggered the braking command is resolved. Some relay equipment can therefore receive information transmitted by the source equipment which is no longer relevant and which it is no longer useful to process locally and/or to retransmit.

Another use case can be to select a route from a source device (or node) of an ad hoc network to a determined destination device (or node) of this network to transmit information to it (for example a command such as mentioned above or any other type of information). As in the previous use case, time constraints may apply. For example, the information transmitted may be of limited duration, or for reasons of performance and user experience, it may be desirable for the information to reach the destination equipment as quickly as possible via the ad hoc network, or even via a number limited relay equipment.

The operating principle of multi-hop transmissions, however, makes it complex to determine the overall transmission time of the radio signal from a source device to a particular destination device, in particular because the interference received at each relay device is amplified in same time as the useful signal.

The invention improves the situation.

In particular, the invention meets the need to guarantee that an information transmission delay constraint between the source equipment and a destination equipment, whether the latter is identified a priori or not, is satisfied.

Presentation of the invention

The invention meets this need by proposing a method for controlling a multi-hop transmission in a wireless communication network, said transmission being implemented by a system comprising a source equipment and a plurality of relay equipment configured to receive, amplify and retransmit a radio signal emitted by the source equipment. Said method comprises, for a relay device of the so-called current system, placed i hops from the source device, with i non-zero integer:

- Obtaining for said current relay equipment a current power ratio between a radio signal power and a noise and interference power, received by said current relay equipment;

- the determination of a current intermediate transmission delay of payload data carried by said radio signal between said source equipment or a previous relay equipment placed at i-1 hops and said current relay equipment, said current intermediate delay being a function of said power ratio current obtained, of a volume of payload data received by said current relay equipment and of a transmission bandwidth of this volume between the source equipment or the preceding relay equipment and said current relay equipment;

- estimation of an overall transmission delay of the radio signal from the source equipment to a final relay equipment placed at a number N of hops, with N integer greater than or equal to i, at least from the intermediate transmission delay determined current and at least one previously determined intermediate delay for a relay device located i-1 jumps or less from the source device; and

- if the estimated overall transmission delay reaches or exceeds a given maximum delay, modifying a multi-hop transmission configuration of said system.

Thus, the invention proposes an entirely new and inventive approach to the management of a multi-hop transmission in a wireless communication network, which consists in estimating during the transmission of payload data sent by a participating source equipment to this transmission, an overall transmission delay of these data to a relay equipment placed at N hops from the source equipment, at least on the basis of power information received from the relay equipment which has already relayed the received radio signal. According to the invention, when the estimated delay exceeds a maximum authorized delay, the multi-hop transmission configuration of the system is modified. Such a configuration modification may concern selection parameters for a route or the selection of a new route to a destination device from among a plurality of routes, new rules defining the conditions for retransmission of all or part of the volume of payload data received by a relay device, for example according to a number of hops separating it from the source device, the stopping of the retransmission beyond a relay device located at a given number of hops, etc. It can be applied immediately to the transmission in progress or to a transmission of a next volume of data by the communication system. It can be transmitted in a specific action message or integrated into the next data volume transmitted by the source equipment. It can relate to one or more communication devices of the system. In this way, the invention makes it possible to check that the relay equipment items of the multi-hop transmission system satisfy a predetermined delay constraint.

According to one aspect of the invention, the estimation of the overall transmission delay of said radio signal from the source equipment to a final relay equipment placed at a number N of hops is implemented once the power ratios have been obtained and the intermediate transmission delays have been determined for the plurality of relay equipment participating in the transmission and the selected configuration is implemented for the transmission of a next radio signal by the source equipment.

According to this embodiment, the overall transmission delay of a previous or pilot data volume is estimated upstream to a recipient located N hops away and it is verified that a maximum delay constraint is satisfied. If this is not the case, the configuration of at least one communication device participating in the transmission is modified. For example, it is the source device that must modify its route selection configuration, so that the route chosen to route the next volume of data is faster and, for example, includes a lower number of relay devices. .

According to another aspect of the invention, the estimation of the overall transmission delay of said radio signal from the source equipment to a final relay equipment located at a number N of hops is implemented following obtaining the power ratio and the determination of the intermediate transmission delay for the current relay equipment, and the modification of the configuration comprises the sending of an action message comprising at least the modified configuration and an order for the application of said configuration by at least at least one relay device located at i+1 hops and more from the source device.

According to this other embodiment, the overall transmission delay of the volume of data transmitted by the source equipment, during its transmission, is estimated on the fly. Transmission control is exercised by commanding one or more relay equipment located downstream to immediately modify their multi-hop transmission configuration. For example, the modification concerns one or more rules relating to the processing of data received before its retransmission. For example, the processing applied comprises a selection of a part of the data or a compression of the data received. The modification may alternatively concern the stopping or deactivation of the retransmission by the relay equipment located downstream or from a given number of hops.

Advantageously, when N is greater than i, said method comprises the prediction of at least one intermediate delay for at least one following relay device, placed between i+1 and N jumps, at least from the current power ratio or from a power ratio stored in memory for said next relay equipment, and the estimation of the overall transmission delay takes into account the predicted intermediate delays.

To estimate on the fly an overall transmission time of all or part of a data volume to a relay device located further downstream, i.e. a number of hops from the source device greater than that of the current relay equipment, all the necessary intermediate transmission delays are not available. Faced with this problem, the invention proposes to make the realistic hypothesis that the power ratios already obtained for the volume of data being transmitted or for a volume of data previously transmitted, make it possible to predict the power ratios of the relay equipment following which have not yet been obtained. One advantage is to be able to determine in advance whether the relay devices with i+1 hops and more can relay the data to the relay located N hops from the source device without exceeding the maximum authorized transmission delay and, if not is not the case, to modify in time, that is to say before the first of them begins to receive, amplify and relay the data in question, their multi-hop transmission configuration.

Advantageously, the method comprises the determination of a maximum number of relays corresponding to a maximum value of the number of hops N at which the final relay equipment is located, such that a predetermined condition is satisfied, said condition being that the transmission delay global estimated for a number of hops N equal to the maximum number of relays NMax does not reach the maximum delay and the estimated global transmission delay for a number of hops equal to NMax+1 reaches or exceeds said maximum delay; and

- the modified configuration includes the maximum number of relays and a rule for deactivating the retransmission of the radio signal received from the source equipment for a relay equipment located at a hop number greater than or equal to said maximum number of relays.

In this way, the relay devices located at a hop number greater than or equal to the number NMax are reconfigured to deactivate the retransmission of the data signal coming from the source device, which makes it possible to guarantee compliance with the constraint on the maximum transmission allowed.

According to another aspect of the invention, the relay equipment of said plurality transmit on the same frequency band and the estimate of the overall transmission delay comprises a summation of the intermediate transmission delays between the relay equipment placed at N hops and less than source equipment.

Advantageously, the overall transmission delay is expressed as follows: where Voli denotes the volume of payload data received by the current relay equipment (ERi); Wi the transmission bandwidth available at the level of the current relay equipment (ERi); N the number of hops at which the final relay equipment is placed; and SINRi represents the signal to interference+noise ratio at the level of the relay equipment placed at i hops for the radio signal received from the preceding relay equipment (ERi-1).

According to yet another aspect of the invention, the determination of the maximum number of relays comprises the iteration of a step of incrementing the number of jumps N by one unit, of the step of estimating a delay of global transmission for the final relay equipment, as long as the predetermined condition is not satisfied.

The maximum number of relays is obtained digitally using a simple and easy-to-execute computer algorithm. Of course, other algorithms can be envisaged.

According to another aspect of the invention, for i equal to 1, the intermediate transmission delays of the relay equipment located at 2 hops and more from the source equipment are predicted as equal to the current power ratio and the overall transmission delay up to 'at a final relay device placed at N hops is calculated from a signal-to-noise ratio at the level of the relay device placed at i hops defined as follows:

Voli is the volume of data received by the current relay equipment, Wi is the transmission bandwidth at the current relay equipment, and where Q is the power ratio obtained by the relay equipment placed one jump from the source equipment.

According to this embodiment, the control of the transmission is carried out during the transmission of the current data volume, but as soon as the powers measured by the first relay equipment are received, assuming that all the following relay equipments have the same power ratio as him. One advantage is to allow a relatively simple and fast calculation of the overall transmission delay DTG _N to the final relay equipment of rank N.

According to yet another aspect of the invention, the overall transmission delay is estimated as the intermediate transmission delay of the relay equipment having the maximum value and in that the maximum number allowed is calculated as follows: with a defined by the following formula: designates the integer part, where Dmax represents the maximum value of the overall transmission delay, Vol the volume of useful data carried by the radio signal emitted by the source equipment and relayed by the relay equipment, and W the transmission bandwidth available for multi-hop transmission.

An advantage is to obtain a relatively simple analytical expression of the maximum number of jumps allowed. This expression of the overall transmission delay is particularly applicable when the relay equipment of the system transmits on separate frequency bands in half-duplex or else when they share the same frequency band but transmit and receive simultaneously (full-duplex).

The invention also relates to a computer program product comprising program code instructions for the implementation of a method for controlling a multi-hop transmission according to the invention, as described previously, when it is executed by a processor.

The invention also relates to a recording medium readable by a computer on which the computer programs as described above are recorded.

Such recording medium can 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 even a magnetic recording means, for example a USB key or a hard disk.

On the other hand, such a recording medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means, so that the program computer it contains is executable remotely. The program according to the invention can in particular be downloaded on a network, for example the Internet network.

Alternatively, the recording medium may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the aforementioned control method.

The invention also relates to a device for controlling a multi-hop transmission in a wireless communication network, said transmission being implemented by a system comprising a source equipment and a plurality of relay equipment configured to receive, amplify and retransmit a radio signal emitted by the source equipment.

Said device is configured to implement, for a relay device of the so-called current system, placed i hops from the source device, with i non-zero integer: the obtaining for said current relay equipment of a current power ratio between a power of the radio signal and a noise and interference power, received and measured by said current relay equipment;

- the determination of a current intermediate transmission delay of payload data carried by said radio signal between said source equipment or the preceding relay equipment and said current relay equipment, said current intermediate delay being a function of said current power ratio obtained, a volume of payload data received by said current relay equipment and a transmission bandwidth of this volume between the source equipment or the previous relay equipment and said current relay equipment;

- estimation of an overall transmission delay of the radio signal from the source equipment to a final relay equipment placed at a number N of hops, with N integer greater than or equal to i, at least from the intermediate transmission delay determined current and at least one previously determined intermediate delay;

Advantageously, said device is configured to implement the aforementioned multi-hop transmission control method, according to its different embodiments.

Advantageously, said device can be integrated into equipment of the communication network. It is for example the source equipment or a relay equipment of the system. It can also be another communication device of the network, such as for example a base station to which the devices of the system are attached.

Correlatively, the invention relates to a method for processing a multi-hop transmission in a wireless communication network, said transmission being implemented by a system comprising a source equipment and a plurality of relay equipment configured to receive, amplify and retransmitting a radio signal transmitted by the source equipment.

Said method comprises, for a relay device of the so-called current system, placed i hops from the source device, with i non-zero integer:

- the transmission to a control device of the wireless communication network of at least one power of a radio signal and one power of noise and interference received by said current relay equipment; and

- the reception from said control device of an action message comprising at least one modification of multi-hop transmission configuration of said system and an order for implementing said modification.

With the invention, the relay equipment located i hops from the source equipment for the transmission of a volume of data transmitted by the source equipment to a destination equipment, is configured to modify its multi-hop transmission configuration in accordance with the instructions of the controlling device.

According to one aspect of the invention, said modified configuration comprises at least a maximum number of relays greater than or equal to i and a ban on retransmitting the radio signal received from the source equipment and the order of application is intended for the equipment relays located at a number of hops greater than or equal to said maximum number of relays.

The advantage of this embodiment is to limit the number of jumps authorized within the system to retransmit the data from the source equipment, to a maximum number determined to guarantee the maximum delay constraint.

According to another aspect of the invention, the method comprises the decision to execute the application order included in the message when the number of hops i from the relay equipment to the number N received is greater than or equal to the number N received.

An advantage is that when the action message is intended for a group address, the relay equipment determines whether it must perform the action included in the message by comparing the number of hops i which separates it from the source equipment. to the maximum number of relays NMax indicated in the action message.

The invention also relates to a computer program product comprising program code instructions for the implementation of a method for processing a multi-hop transmission according to the invention, as described previously, when it is executed by a processor.

Alternatively, the recording medium may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the aforementioned processing method.

The invention also relates to a device for processing a multi-hop transmission in a wireless communication network, said transmission being implemented by a system comprising a source equipment and a plurality of relay equipment of the wireless communication network, configured to receive, amplify and retransmit a radio signal emitted by the source equipment.

Said device is configured to implement, for a relay device of the so-called current system, placed i hops from the source device, with i non-zero integer:

- the transmission to a wireless communication network control device of at least one radio signal power and one noise and interference power received and measured by said current relay equipment; and the reception from said control device of an action message comprising at least one modification of a multi-hop transmission configuration of said system and an order for applying said modification.

Advantageously, said device is configured to implement the aforementioned processing method, according to its various embodiments.

Advantageously, said device is integrated in relay equipment of the system. Correlatively, the invention also relates to relay equipment of a wireless communication network, configured to receive, amplify and retransmit a radio signal emitted by a source equipment and received from the source equipment or from a previous relay equipment, said relay equipment comprising the aforementioned processing device.

The invention also relates to source equipment in a wireless communication network, said source equipment being configured to transmit a radio signal in said communication network and comprising the aforementioned control device.

The invention also relates to communication equipment in a wireless communication network comprising the aforementioned control device.

The invention finally relates to a multi-hop transmission system in a wireless communication network, comprising source equipment configured to transmit a radio signal in said network and a plurality of relay equipment configured to receive, amplify and retransmit the radio signal transmitted by the source equipment, the system comprising the aforementioned control device and the said relay equipment comprising the aforementioned processing device.

Brief description of figures

Other aims, characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of a simple illustrative example, and not limiting, in relation to the figures, among which:

[Fig 1]: presents an example of the architecture of a multi-hop transmission system implemented in a wireless communication network comprising, a source equipment, a plurality relay equipment and a device for controlling said transmission, configured to control said plurality of relay equipment according to the invention;

[Fig 2]: schematically illustrates an example of the architecture of the device for controlling a multi-hop transmission implemented in a wireless communication network by said system and of relay equipment of said system, integrating a device multi-hop transmission processing, according to one embodiment of the invention;

[Fig 3]: describes in the form of a flowchart the steps of a method for controlling a multi-hop transmission, according to an exemplary embodiment of the invention;

[Fig 3]: describes in the form of a flowchart the steps of a method for processing a multi-hop transmission by a relay device of said plurality, according to an embodiment of the invention;

[FIG 5]: describes an example of hardware structure of a multi-hop transmission control device implemented in a wireless communication network according to the invention; and [FIG 6]: describes an example of hardware structure of a multi-hop transmission processing device implemented in a wireless communication network, according to the invention.

Detailed description of the invention

The principle of the invention consists in estimating an overall transmission delay of a data signal by a multi-hop transmission in a wireless communication network, said transmission being implemented by a system comprising a source equipment and a plurality relay equipment configured to receive, amplify and retransmit a radio signal transmitted by the source equipment, and to verify that this overall transmission delay is less than or equal to a maximum authorized delay. Such an estimate is based on at least one power ratio between a power of a radio signal and an interference and noise power received by relay equipment of the system, said relay equipment being located i hops from the equipment source, with i less than or equal to N and at least one intermediate delay previously determined for a relay device located i-1 hops or less from the source device.

When the overall transmission delay estimates that it has reached or exceeded a maximum delay, a modification of the multi-hop transmission configuration of the system is decided and implemented, for example by sending an action message to the communication equipment concerned, which can be the source equipment itself and/or one or more relay equipment in the system. This modified configuration can be applied to the transmission of the current radio signal or to that of a future radio signal.

The configuration modification defines new rules or parameters for processing a volume of data to be transmitted or retransmitted by these communication devices. It is by example of new rules or parameters for selecting a route to route the volume of payload data to one or more destination devices. It can also define rules for processing the volume of payload data by a relay equipment, comprising for example a compression of such data or a deletion of data intended specifically for the current relay equipment, leading to the retransmission of a sub-volume the amount of data received. If the data includes commands, these processing rules can define a conversion into more basic commands and therefore more economical in transmission resources.

The configuration modification can also define a maximum number of relays and processing rules relating to this maximum number of relays, such as for example a ban on retransmitting the data received when this number of relays is reached or exceeded or even the search for a route comprising a number of relays less than or equal to this maximum number. The invention finds a particularly interesting application in the management of lines of vehicles, at least partially autonomous. In this case of use, each vehicle integrates a mobile terminal equipment, configured to transmit to vehicles located in the vicinity information relating to the vehicle control commands, for example during a change of direction, braking, etc. type.

Of course, the invention is not limited to this example of use case, but could also apply in other contexts, such as for example to a system of interconnected production machines in a factory or more generally to any system of connected objects.

We now present, in relation to FIG. 1, an example of architecture of a system 10 for managing a multi-hop transmission in a wireless communication network, for example cellular radio, implementing a source equipment ES , for example a first vehicle which carries mobile communication equipment and transmits a signal carrying a volume of useful data Vol in the network which is then relayed by a plurality of relay equipment ER1-ERN, for example other vehicles each carrying mobile communication equipment. It is assumed for example that all the mobile communication equipment of these vehicles are attached to the same base station BS.

As illustrated by FIG. 1, the system 10 according to the invention comprises the source equipment ES, the plurality of relay equipment ER1-ERN and a communication equipment EC, configured to control the processing of the multi-hop transmission by the plurality of relay equipment ER1-ERN according to the invention. It is for example the base station BS, the source equipment ES, one of the relay equipments of the plurality or even another communication equipment EC also attached to the base station BS. In the remainder of the description, the focus will be on describing more particularly the case of a group of vehicles in platoons or road convoy traveling in an at least partially automated road system. In this context, known as V2X (for "vehicle to anything"), the source equipment (or first communication equipment) broadcasts data to the group via a "sidelink" or SL communication channel depending on the 3GPP RAN specifications. The messages broadcast are for example of the CAM (for “Cooperative Awareness Message”) type.

According to this technology, the communication equipment of the same group of vehicles are attached to the same base station and are part of the same broadcasting group, that is to say that the messages or volumes of data exchanged are destined for the same group address. In the example of FIG. 1, the group of vehicles comprises the source equipment ES, the relay equipment ER1, ER2, ER3...ERN. Thanks to V2X communication, the vehicles in the platoon can accelerate or brake in unison.

The base station transmits to the equipment of the group the time-frequency resources to be used to broadcast these messages. It also transmits to them other useful information for implementing the multi-hop transmission, such as for example the network address of a communication device integrating a control device according to the invention.

Of course, the invention is not limited to this embodiment, but applies to any direct transmission, that is to say without passing through the base station, between a source equipment and a destination equipment by the intermediary of a plurality of relays. For simplicity, however, it is assumed that all the equipment involved is attached to the same base station.

In the embodiment described here, it is also assumed that all the communication equipment involved in the multi-hop transmission uses the same frequency band, for example equal to 10 MHz. Of course, this value is only given by way of illustration and does not limit the invention.

The invention also applies to any wireless, non-cellular communication network, such as for example a Wi-Fi network, managed by a residential or professional gateway. In this case, the communication equipment implemented in the multi-hop communication obtains the information necessary for the implementation of this direct communication from the gateway. It applies more generally to any type of network, such as a satellite network or even an ad hoc network of connected objects, for example of the LoRa or Sigfox type (registered trademarks).

FIG. 2 presents an example of architecture of the communication equipment EC according to one embodiment of the invention. According to this example, the communication equipment EC comprises a device 100 for controlling a multi-hop transmission according to the invention. This device includes least one OBT module. PUi,Pli for obtaining at least one relay device ERi, called current relay, of said plurality ER1-ERN, located i jumps from the source device ES, with i non-zero, a current power ratio PINRi between a power PUi of the radio signal and a noise and interference power Pli, received and measured by said relay equipment, a module DET. DTi for determining an intermediate transmission delay DTi of the volume of data between said source equipment or the previous relay equipment ERi-1 placed at i-1 hops from the source equipment ES and said current relay equipment ERi, a module EST . DTG _N for estimating an overall transmission delay DTG _N of said data volume from the source equipment to a relay equipment placed at N hops, with N integer greater than or equal to i, at least from the intermediate transmission delay (DTi) determined current and previously determined intermediate times; and a MOD modification module. CNF of a System 10 multi-hop transmission configuration, configured to be implemented when the estimated overall transmission delay reaches or exceeds a given maximum delay (e.g., exceeds a maximum delay allowed for multi-hop transmission). Alternatively, the device 100 can be independent of the equipment EC, but connected to the latter by any link, wired or not.

Advantageously, device 100 includes a prediction module PRED. DTi of at least one intermediate delay for at least one following relay device with respect to the current relay device ERi, this following relay device being placed between i+1 and N jumps. The PRED prediction module. DTi is configured to predict the intermediate delay at least from the current power ratio PINRi. The device 100 also comprises, in a particular embodiment, a DET module. NMax for determining a maximum number of relays corresponding to a maximum value NMax of the number of hops N at which the final relay equipment is located, such as the overall transmission delay DTG _N estimated for a number of hops N equal to the maximum number NMax is less than or equal to said given maximum overall transmission delay DMax and the estimated overall transmission delay DTG _N for a number of hops N equal to NMax+1 is greater than said given maximum overall transmission delay DMax.

Advantageously, the device 100 comprises at least one TX/RX module for transmitting and receiving signals in the communication network and a data storage module M1. Alternatively, it uses the transmission/reception module and/or the storage module of the communication equipment EC in which it is integrated.

The non-volatile memory M1 advantageously comprises the power reports received from the previous relay equipments and the intermediate transmission delays determined for these previous relay equipments. The device 100 thus implements the method for controlling a multi-hop transmission implemented by a plurality of relay equipment within a wireless communication network according to the invention which will be detailed below in relation with Figure 3.

In the remainder of the description, it is assumed that this device 100 knows the relay equipment participating in the communication. For example, it has received information about these relay devices in messages sent through traffic channels or common channels.

FIG. 2 also presents an example of architecture of relay equipment ERi according to one embodiment of the invention. The relay equipment ERi is located i hops from the source equipment ES, with i non-zero. According to this example, the relay equipment ERi comprises a device 200 for processing a multi-hop transmission, within which the source equipment ES has transmitted a radio signal carrying a volume of payload data. A radio signal carrying all or part of this useful data volume is received by the relay equipment ERi from this source equipment or from a previous relay equipment ERi-1 located at a number of hops i-1 from the source equipment .

The processing device 200 integrated in this relay equipment ERi comprises at least one transmission module TRNS. PUi, Pli of a power of the data signal and a noise and interference power which it has received and measured, to a control device 100 as described previously, and to receive REC. MA an action message comprising a multi-hop transmission configuration modification and an order for implementing this modification. Alternatively, the device 200 can be independent of the relay equipment ERi, but connected to the latter by any link, wired or not.

Advantageously, the processing device 200 also comprises an STR module. MOD for storing the configuration modification received and a DEC module. decision to implement the configuration modification included in the message, when it is intended for the relay equipment ERi.

Advantageously, the device 200 also comprises a TX/RX module for receiving and transmitting information in the wireless communication network and a data storage module M2, for example a non-volatile memory.

The device 200 thus implements the method for processing a multi-hop transmission according to the invention which will be detailed below in relation to FIG. 4.

We now present, in relation to FIG. 3, in the form of a flowchart, an example of implementation of a method for controlling a multi-hop transmission in a wireless communication network according to the invention. A source equipment ES has transmitted, within the framework of this transmission, a signal carrying a volume Vol of payload data in the network. For the sake of simplification, to better understand the invention, the following description will assume that this same Vol volume of payload data is relayed as it is by the plurality of relay equipment. It should however be noted that the invention also applies in a context where on each retransmission, the volume of payload data relayed by a relay equipment ERi can increase or decrease with respect to the volume Vol of payload data sent by the source equipment ES. More specifically, each relay equipment ERi relays to the relay equipment ERi+1 according to a volume Voli+1 of payload data comprising all or part of the volume Voli of payload data received from the previous relay equipment ERi-1 or from the source equipment ES according to the value of i, possibly supplemented by other useful data added by the relay equipment ERi.

In other words, in general, each volume Vol of payload data is derived from the volume Vol of payload data transmitted by the source equipment ES. In this case, it is assumed that the control device 100 has received information relating to this volume Voli from the relay equipment ERi.

For the sake of simplification, the assumption is also made that the available bandwidth W is the same at the level of each communication equipment participating in the transmission, source equipment and relay equipment. For example, this bandwidth can be fixed a priori at an identical value W for all the relay equipment ERi of the system 10.

However, the invention is not limited to this particular case and also applies when the Wi transmission bandwidth varies from one communication device to another. In particular, it can be modified in certain contexts by the relay equipment ERi, for example on instruction from a user, from the base station, from the control device 100 etc.

At 30, a current power ratio PINRi between a power of the radio signal and a measured noise and interference power is received from a relay equipment ERi, called current relay equipment of said plurality of relay equipments, placed at the th hop, with i non-zero integer, of the source equipment ES in the multi-hop transmission implemented by the system 10.

At 31, an intermediate transmission delay DTi of the data volume during the ith hop is determined. This is the section connecting the previous relay equipment ERi-1 to the current relay equipment i. Said current intermediate delay DTi is a function of said power ratio PINRi obtained, of the volume Vol of data received and of a transmission bandwidth W between the previous relay equipment and said current relay equipment.

At 32, an overall transmission delay DTG _N of said data volume from the source equipment ES to a relay equipment placed N hops from the source equipment ES, with N integer greater than or equal to i is estimated at least at from the current intermediate transmission delay (DTi) determined and, where appropriate, from intermediate delays previously determined by previous relay equipment placed at i-1 hops and less.

At 33, the estimated global transmission delay DTG _N is compared with a given maximum delay. For example, it is determined whether it is less than or equal to a maximum authorized delay DMax for multi-channel transmission. jumps. Note that it could also be compared to a delay threshold not to be crossed by checking whether it is strictly below this threshold.

If the maximum authorized delay DMax is exceeded, a multi-hop transmission configuration of the system 10 is modified at 34. For example, the modification comprises a rule for deactivating the retransmission of the data of the radio signal received by a relay equipment ERi s' it is located at a number of jumps greater than or equal to a determined maximum number of relays. Another configuration example is to require the compression of the data received and/or to define parameters for this compression. Yet another example consists in defining selection rules for all or part of the volume of data received, for example by deleting the data which was intended specifically for the current relay equipment, or even a priority being associated with the various data, by not keeping than the highest priority. Yet another example is to modify the rules for selecting a route from among several available to relay the radio signal to a destination device and to select the shortest in terms of transmission delay.

Optionally, the modification comprises the sending of an action message MA comprising at least the configuration modification and an order for the application of this modification, intended for at least one communication device of the system participating in the multi-transmission. jumps. When it is intended for communication equipment other than that which implements the control method according to the invention, the action message is transmitted in the wireless communication network via the base station or else according to a mode of direct step-by-step communication, as the source equipment ES does. Note, however, that when the control method is implemented by the source equipment or one of the relay equipment participating in the transmission, the application of the selected configuration may include an update of the current configuration within this equipment without requiring the sending of such a message.

The step 32 of estimating an overall transmission delay DTG _N reached at the level of the relay equipment ERN located at N hops from the source equipment ES, with N greater than or equal to i, will now be detailed. This estimate is not obvious because each relay device reamplifies the useful signal, interference and thermal noise. After N jumps, the signal obtained consists of the initially transmitted signal and reamplified interference and noise. The estimation of the overall transmission delay therefore requires knowledge of the signal to noise ratio SI N Ri at the level of each relay equipment ERi, which the invention advantageously allows from the information available at the level of the relay equipment ERi.

In general, this delay between ES and ERN can be estimated as the sum of the intermediate delays DTi from the source equipment ES to the final relay equipment ERN:

DTG _N = DTI + DT2+...+DTN However, we know that the transmission delay between an ERi-1 relay device and an ERi relay device can be expressed as follows: with :

Voli the volume of payload data actually received by the current relay equipment ERi. It may be different from the volume of useful data Vol transmitted by the source equipment ES, Wi the bandwidth allocated to the relay equipment ERi; SI N Ri the signal-to-noise ratio at the level of the ERI relay equipment, also called z^.

Assuming Voli=VOL and Wi=W for all i, equation (1) becomes:

Thus, the global transmission delay DTGN can be estimated as follows:

The signal-to-noise ratio SINRi depends on the current power ratio PI N Ri. More precisely, we have: where qί represents the current power ratio PINRi at the relay ERi, with PINRi = PUi/Pli,

PUi being the power of the signal received and measured by the relay equipment ERi coming from the previous relay equipment ERi-1 and

Pli the sum of the interference powers received and measured by the relay equipment ERi coming from all the communication equipment of the system 10, to which is added the thermal noise.

We therefore obtain:

In the remainder of the description, the assumption is made that the volume of data Vol transmitted by the system remains the same throughout the transmission and that the passband W is identical at the level of each of the communication equipment items of the system.

In this case where Wi=W and Voli=Vol for all i, we can simplify the expression of the global transmission delay as follows: At this stage, there are at least three embodiments of the invention:

- a first mode, called "upstream", according to which the method is implemented before the actual transmission of the data volume Vol by the source equipment ES, from powers obtained from the relay equipment ER1-ERN for the transmission from a pilot or previous data volume to one or more destination devices. This first mode makes it possible to adjust the configuration of the source equipment and possibly of the plurality of relay equipment ER1-ERN.

- a second mode, called “as you go”, according to which the overall transmission rate DTG _N is estimated from the power ratios, as they are obtained. In other words, N=i and the final relay device ERN corresponds to the current relay device ERi. This embodiment makes it possible to modify the multi-hop transmission configuration of the system with a view to the transmission of a next data volume Vol′; and

- a third mode, called "in anticipation", according to which N is strictly greater than i and the transmission rate is estimated not only from the current and previous power ratios, but also from power ratios predicted for the equipment relays located at i+1 hops and more from the source equipment ES. This embodiment makes it possible to adjust the configuration of the relay equipment ERi+1-ERN located downstream of the current relay equipment with respect to the source equipment ES during the transmission of the data volume Vol.

According to the first embodiment, the overall transmission delay DTG _N of the useful data volume Vol is estimated at 32 as far as the final relay equipment ERN, which is here the destination equipment, using the equation 4bis. In this first embodiment, the number N is for example fixed.

At 33, it is compared with the maximum authorized transmission delay DMax and it is verified, in the case where the volume of data Vol is unchanged during the transmission and the transmission bandwidth W is constant, that

If this condition is verified, no configuration change is decided.

On the contrary, if it is not verified, a modification of the transmission configuration of one or more communication devices of the system is decided.

For example, this is a new configuration for the ES source device and the current configurations for the ER1-ERN relay devices are unchanged. For example, this new configuration defines new route selection rules and/or a maximum number of authorized relays.

Alternatively or in combination, configuration modifications are decided for the relay equipment ER1-ERN at 34 and one or more action messages MA comprising these new configurations are transmitted to them at 35 in the wireless communication network. They can be transmitted specifically to each of the relay equipment concerned or else to all of them and in this case, each relay equipment is configured to decide whether it must implement the configuration received in the message. This aspect will be detailed in relation to Figure 4.

According to another option, when the control method is implemented by the source equipment ES, the configuration modifications are transmitted to the communication equipment of the system with a next volume of data Vol' which it transmits within the system of multi-hop transmission. According to the second embodiment, the overall transmission delay DTGi as far as the relay equipment ERi is also estimated at 32 using equation 4bis. In this second embodiment, the number N is for example fixed.

If this condition is verified, no configuration change is decided.

On the contrary, if it is not verified, a modification of the multi-hop transmission configuration of one or more relay equipment located i hops and more is decided at 34 and an action message MA comprising this configuration modification is transmitted at 35 in the wireless communication network, at least to the relay equipment concerned.

According to the third embodiment, called "in anticipation", N is chosen strictly greater than i and we are interested in the determination of N making it possible to respect a constraint of the overall transmission delay with respect to the maximum transmission delay authorized . To estimate the overall transmission delay DTG _N up to the final relay equipment ERN, the intermediate transmission delays corresponding to the jumps between i+1 and N for which the power ratios PINRi+ have not yet been obtained are predicted. 1 - PINRN, from the current power ratio PIN Ri and possibly previous ones, stored in memory. For example, it is assumed that PINRi+1 = PINRi+2 = ...PINRN = PINRi = Q,·.. The overall transmission delay DTG _N is thus obtained as far as the final relay equipment ERN using equation 4bis and it is compared at 33 with the maximum authorized delay DMax at 33 as in the previous case.

If it is strictly less than the maximum authorized delay DMax, it is advantageously possible to increment the value of N by one unit and restart the estimation for N=N+1 as previously described, compare the result obtained with the maximum authorized delay, and continue thus until the global transmission delay DTG _N exceeds the maximum allowed delay. The last value of N which does not exceed the maximum allowed delay then corresponds to the maximum number NMax of jumps and therefore of relays authorized to retransmit the volume of data Vol transmitted by the source equipment ES by the multi-hop transmission system while ensuring the constraint on the maximum authorized delay.

The advantage of this anticipation mode is on the one hand to be able to modify the multi-hop transmission configuration of the relay equipment located i+1 hops and more from the current relay equipment, before they receive the carrier signal data emitted by the source equipment ES, and therefore with an increased impact.

On the other hand, the determination of the maximum number of relays authorized NMax makes it possible to control in a simple and efficient manner the relay equipment of the system which is implemented in the multi-hop transmission. Indeed, such a control can be carried out by configuring a deactivation of the retransmission of the radio signal received from the source equipment and ordering its execution to all the relay equipment located at NMax hops and more from this source equipment, and thus to guarantee that the given maximum transmission delay DMax will not be exceeded.

Within this third embodiment, the particular case is now considered where it is considered that all the relay equipment items ER1-ERN have the same power ratio PINRi. We consider in particular the implementation of the control method according to the invention for i=1. The control device 100 obtains the power ratio PINRI and predicts the following power ratios PINR2-PINR _N as being equal to PINR1=Q .

In this case, the previous equations simplify as follows:

We have : so

It can be deduced from this that the intermediate transmission delay DTi on a link corresponding to jump i between the relay equipment ERi-1 and the relay ERi is less than the transmission delay on the link corresponding to jump i+1 between the relay ERi and the ERi+1 relay.

As a result, the intermediate transmission delays increase between the source equipment ES and the final relay equipment ERN: In the case where a relay equipment ERi can retransmit without delay and upon receipt of the ^1st byte to the following relay equipment ERi+1 the data it receives from the previous relay ERi-1, for example because they use distinct frequency bands, we therefore have:

If we generalize, we get: Thus, the condition on the global transmission delay DTG _N becomes:

So we have :

We put:

Where DMax is the given or allowed maximum delay.

The previous condition translates as follows:

So we have :

So

That is

So

So As mentioned before, NMax denotes the maximum number of relays allowed guaranteeing the maximum allowed delay constraint DMax, in other words, NMax corresponds to the maximum value of N such that it follows, as well as from inequality (11), that: where [ J denotes the integer part.

A precise analytical expression of the maximum number of relays authorized is thus obtained.

For example, for a volume of data Vol = lKo and a bandwidth W = 1 MHz, a power ratio Q = 0.8, the signal-to-noise ratio is worth x = 2.25, V= 1 kbits, W =1 MHz and we obtain: for DMax fixed at 10s, NMax = 10 relay devices; for DMax fixed at ls, NMax = 7 relay devices.

We have just detailed an embodiment in which the following simplifying assumptions have been made:

- the volume of Vol payload data relayed remains constant from end to end of the multi-hop transmission,

- the bandwidth W is constant within the multi-hop transmission system,

- each relay equipment of the system retransmits without delay the data received from a previous relay equipment.

Of course, the invention is not limited to this particular case, but the invention also applies in the general case. By relying on equations (4) and (5), an analytical expression of the global delay DTG _N can be derived according to considerations similar to those implemented in this particular example. It is noted that if the analytical expression of the global transmission delay is too complex to allow an analytical resolution, it is possible to resort to a numerical method, easily executable by computer, in order to obtain the maximum number of authorized relays. Such a method consists for example in implementing a simple algorithm comprising a test loop of successive values of the number of jumps N and an exit from the loop as soon as the condition given on the maximum delay DMax is no longer respected.

We now present, in relation to FIG. 4, in the form of a flowchart, an example of implementation by a relay equipment of a wireless communication network of a method for processing a multi-hop transmission implemented. works in this wireless communication network. It is assumed that it is a relay device of the system 10, for example the relay device ERi located i hops away, with i non-zero integer, from the source device ES having transmitted the volume of payload data Flight as part of the multi-hop transmission. Advantageously, the method is implemented by the processing device 200.

At 40, the relay equipment ERi receives a radio signal carrying all or part of the useful data volume Vol transmitted by the source equipment ES, from this source equipment if i=1 and from a previous relay equipment ERi-1 if i>l.

At 41, the relay equipment ERi measures a power PUi of the radio signal received from the source equipment or from the preceding relay equipment and a power Pli of the interference received from all the communications equipment located nearby, to which adds thermal noise.

At 42, it transmits the powers PUi and Pli measured to a control device 100 according to the invention. It is assumed that he knows the network address of this device 100 because he obtained it beforehand from the base station BS or else that he transmits the powers to the base station which is responsible for sending them back to the device control 100.

At 43, it receives an action message MA from the control device 100. This message comprises at least one modification of the multi-hop transmission configuration of the system 10 and an implementation order intended for one or more relay equipment of this system.

At 44, it stores the configuration change.

According to a particular embodiment, the configuration modification comprises a maximum number of relays NMax and the order of application is intended for relay equipment located at NMax hops and more from the source equipment ES.

For example, the configuration includes a maximum number of relays NMax and a rule for deactivating the retransmission of the volume of data received and the order of application concerns the relay equipment located at NMax hops and more from the source equipment ES.

Advantageously, the maximum number of relays NMax received is stored in memory at 44.

In 45, it is compared with the number of hops i of the relay equipment ERi and decided whether the modification of retransmission configuration received must be executed according to the result of this comparison. If i is greater than or equal to NMax, the device 200 modifies its current configuration using the new configuration received, which becomes applicable to the next data that it will receive from a previous relay equipment within the framework of the multi-channel transmission. jumps.

At least the following two cases can be distinguished:

- According to a first case, the reception at 40 of the data signal coming from the source equipment precedes the reception at 43 of the action message MA. The relay equipment ERi therefore knows its number of hops i in the multi-hop transmission, it can therefore decide immediately at 45 if it must execute the action included in the message and if necessary execute it,

- According to a second case, the reception at 40 of the data signal coming from the source equipment follows the reception at 43 of the action message MA. It is assumed that the relay equipment does not does not yet know its number of hops in the multi-hop communication. In 44, it stores in memory the number of hops NMax as well as the retransmission configuration received in the action message and waits to receive the radio signal in 40. On reception, it triggers step 45 of decision to whether or not to execute the received action.

We now present, in relation to FIG. 5, another example of hardware structure of a device 100 for controlling a multi-hop transmission implemented by a system in a wireless communication network according to the invention, said system comprising a source equipment configured to transmit a radio signal carrying a volume of data and a plurality of relay equipment configured to receive, amplify and retransmit a radio signal received from another relay equipment or from the source equipment. According to this example, the control device 100 comprises, as illustrated in FIG. 2, at least one module for obtaining, a module for determining, an estimation module and a module for modifying a multi-hop transmission configuration of the system.

The term "module" can correspond both to a software component and to a hardware component or a set of hardware and software components, a software component itself corresponding to one or more computer programs or sub-programs or in a more general to any element of a program capable of implementing a function or a set of functions.

More generally, such a device 100 comprises a random access memory 103 (for example a RAM memory), a processing unit 102 equipped for example with a processor, and controlled by a computer program Pg, representative of the modules for obtaining, determination, estimation, selection and implementation, stored in a read only memory 101 (for example a ROM memory or a hard disk). On 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. The random access memory 103 can also include the transmission delays determined intermediates, as well as the power ratios obtained from the powers measured by the relay equipment.

FIG. 5 only illustrates one particular way, among several possible, of making the device 100 so that it performs the steps of the method for controlling a multi-hop transmission in a wireless communication network as detailed above, in relation to FIG. 3 in its various embodiments. Indeed, these steps can be carried out either on a reprogrammable calculation machine (a PC computer, a DSP processor or a microcontroller) executing a program comprising a sequence of instructions, or on a dedicated calculation machine (for example a set of logic gates like an FPGA or an ASIC, or any other hardware module).

In the case where the device 100 is produced with a reprogrammable calculating machine, the corresponding program (that is to say the sequence of instructions) can be stored in a medium of removable storage (such as for example an SD card, a USB key, a CD-ROM or a DVD-ROM) or not, this storage medium being partially or totally readable by a computer or a processor.

The different embodiments have been described above in relation to a device 100 integrated in a communication device of the network, for example the source device ES, the base station BS or one of the relay devices of the system, but it can also be independent of the communication equipment in question and connected to it by any link.

There is also presented, in relation to FIG. 6, another example of hardware structure of a device 200 for processing a multi-hop transmission in a wireless communication network according to the invention, comprising, as illustrated by the example of Figure 2, at least one module for transmitting and one module for receiving an action message.

More generally, such a device 200 comprises a random access memory 203 (for example a RAM memory), a processing unit 202 equipped for example with a processor, and controlled by a computer program Pg2, representative of the transmission and reception modules , stored in a read only memory 201 (for example a ROM memory or a hard disk). On initialization, the code instructions of the computer program are for example loaded into the RAM 203 before being executed by the processor of the processing unit 202.

FIG. 6 only illustrates one particular way, among several possible ways, of making the device 200 so that it performs the steps of the processing method as detailed above, in relation to FIG. 4 in its various embodiments. Indeed, these steps can be carried out either on a reprogrammable calculation machine (a PC computer, a DSP processor or a microcontroller) executing a program comprising a sequence of instructions, or on a dedicated calculation machine (for example a set of logic gates like an FPGA or an ASIC, or any other hardware module).

In the case where the device 200 is produced with a reprogrammable calculation machine, the corresponding program (that is to say the sequence of instructions) can be stored in a removable storage medium (such as for example an SD card , a USB key, a CD-ROM or a DVD-ROM) or not, this storage medium being partially or totally readable by a computer or a processor. The invention which has just been described in its various embodiments has numerous advantages. In general, it applies to a group of objects connected in a wireless communication network, such as for example a line of vehicles, which transmit information step by step according to a direct and multi-hop communication mode. or machines on the same production line.

The invention indeed proposes to estimate an overall transmission time of data transmitted by a source connected object to one or more destination connected objects via a plurality of relay connected objects from powers measured by these relays , without requiring a step-by-step calculation. The invention then exploits this estimate to control the multi-hop transmission by modifying the retransmission configuration of the communication equipment of the system implementing this transmission, which allows it to guarantee that the transmission time of this data does not exceed one given maximum delay, e.g. allowed. The invention makes it possible in particular to avoid the reception and therefore the taking into account by the destination equipment or equipment of data that have become obsolete due to too high a latency.

Claims

1. Method for controlling a multi-hop transmission in a wireless communication network, said transmission being implemented by a system comprising a source equipment and a plurality of relay equipment configured to receive, amplify and retransmit a radio signal transmitted by the source equipment, characterized in that said method comprises, for a relay equipment of the so-called current system, placed i hops from the source equipment, with i non-zero integer:

the obtaining (30) for said current relay equipment (Ri) of a current power ratio (PINRi) between a power of the radio signal and a noise and interference power, received by said current relay equipment;

- the determination (31) of a current intermediate transmission delay (DTi) of payload data carried by said radio signal between said source equipment or a previous relay equipment placed at i-1 hops and said current relay equipment, said current intermediate delay (DTi) being a function of said current power ratio obtained, of a volume (Vol, Voli) of payload data received by said current relay equipment and of a transmission bandwidth (W, Wi) of this volume between the equipment source or the previous relay equipment and said current relay equipment;

- the estimation (32) of an overall transmission delay (DTG _N ) of the radio signal from the source equipment to a final relay equipment placed at a number N of hops, with N integer greater than or equal to i, at least from the current intermediate transmission delay (DTi) determined and from at least one intermediate delay previously determined for a relay device located i-1 hops or less from the source device;

- if the estimated overall transmission delay reaches or exceeds a given maximum delay (DMax), modifying (34) a multi-hop transmission configuration of the system.

2. Control method according to claim 1, characterized in that the estimation of the overall transmission delay (DTG _N ) of said radio signal from the source equipment to a final relay equipment placed at a number N of hops is implemented once the power ratios have been obtained and the intermediate transmission delays have been determined for the plurality of relay equipment participating in the transmission and the selected configuration is implemented for the transmission of a next radio signal by the source device.

3. Control method according to claim 1, characterized in that the estimation of the overall transmission delay (DTG _N ) of said radio signal from the source equipment to a final relay equipment located at a number N of hops is implemented after obtaining the report of powers and the determination of the intermediate transmission delay for the current relay equipment, and in that the modification of the configuration comprises the sending of an action message comprising at least the modified configuration and an order for the application of said configuration by at least one relay device located i+1 hops and more from the source device.

4. Control method according to claim 3, characterized in that, when N is greater than i, said method comprises the prediction of at least one intermediate delay for at least one following relay device, placed between i+1 and N jumps , at least from the current power ratio or from a power ratio stored in memory for said next relay device, and in that the estimation of the overall transmission delay (DTG _N ) takes into account the predicted intermediate delays.

5. Control method according to claim 3 or 4, characterized in that:

- the method comprises the determination of a maximum number of relays corresponding to a maximum value (NMax) of the number of jumps N at which the final relay equipment is located, such that a predetermined condition is satisfied, said condition being that the delay global transmission delay (DTGN) estimated for a number of hops N equal to the maximum number NMax does not reach the maximum delay (DMax) and the global transmission delay estimated for a number of hops equal to NMax+1 reaches or exceeds said delay maximum; and in that :

- the selected configuration includes the maximum number of relays and a ban on retransmitting the radio signal received from the source equipment for a relay equipment located at a hop number greater than said maximum number of relays.

6. Control method according to one of the preceding claims, characterized in that the relay equipment of said plurality transmit on the same frequency band and the estimation of the overall transmission delay (DTG) comprises a summation of the intermediate transmission delays between the relay devices placed at N hops and less from the source device.

7. Control method according to the preceding claim, characterized in that the overall transmission delay is expressed as follows: where Voli denotes the volume of payload data received by the current relay equipment (Eri); Wi the transmission bandwidth available at the level of the current relay equipment (Eri);

N the number of hops at which the final relay equipment is placed; and SINRi represents the signal to interference and noise ratio at the level of the relay equipment placed at i hops for the radio signal received from the preceding relay equipment (ERi-1).

8. Control method according to claims 5 and 7, characterized in that the determination of the maximum number of relays (NMax) comprises the iteration of a step of incrementing the number of jumps N by one unit, the step of estimating a global transmission delay (DTG) for the final relay equipment, as long as the predetermined condition is not satisfied.

9. Control method according to any one of the preceding claims, characterized in that it depends on claim 2 and in that, for i equal to 1, the intermediate transmission times of the relay equipment located at 2 hops and more of the source device are predicted to be equal to the current power ratio and the overall transmission delay to a final N-hop placed relay device is calculated from a signal-to-noise ratio at the placed relay device at i jumps defined as follows: where

Voli is the volume of data received by the current relay equipment (ERi), Wi is the transmission bandwidth at the level of the current relay equipment (Eri), and where θe is the power ratio obtained by the relay equipment (ERI) placed at a source equipment jump.

10. Control method according to claim 5, characterized in that it depends on claim 9, in that the global transmission delay (DTG) is estimated as the intermediate transmission delay (DTi) of the relay equipment having the maximum value and in that the maximum authorized number (NMax) is calculated as follows:

, where [ J denotes the integer part, where DMax represents the given maximum delay,

Vol the volume of useful data carried by the radio signal transmitted by the source equipment, and W the transmission bandwidth available for the multi-hop transmission.

11. Method for processing a multi-hop transmission in a wireless communication network, said transmission being implemented by a system comprising a source equipment and a plurality of relay equipment configured to receive, amplify and retransmit a radio signal transmitted by the source equipment, characterized in that said method comprises, for a relay equipment of the so-called current system, placed i hops from the source equipment, with i non-zero integer: - the transmission (42) to a control device (100) of the wireless communication network of at least one power of a radio signal and one power of noise and interference received by said current relay equipment ; and

- the reception (43) from said control device (100) of an action message comprising at least one modification of multi-hop transmission configuration of said system and an order to apply said modification, said modification of configuration comprising at least a maximum number of relays (NMax) greater than or equal to i and a rule for deactivating a retransmission of the radio signal received from the source equipment, and the implementation order being intended for the relay equipment located to a number of hops greater than or equal to said maximum number of relays.

12. Method for processing a multi-hop transmission according to the preceding claim, characterized in that it further comprises the decision (45) to execute the application order included in the message when the number of hops i of the relay equipment is greater than the maximum number of relays (NMax) received.

13. Device (100) for controlling a multi-hop transmission in a wireless communication network, said transmission being implemented by a system comprising a source equipment and a plurality of relay equipment configured to receive, amplify and retransmit a radio signal emitted by the source equipment, characterized in that said device is configured to implement, for a relay equipment of the so-called current system, placed i hops from the source equipment, with i non-zero integer:

- obtaining (OBT. PUi, Pli) for said current relay equipment (Ri) a current power ratio (PINRi) between a power of the radio signal and a power of noise and interference, received and measured by said current relay equipment;

- the determination (DET. DTi) of a current intermediate transmission delay (DTi) of payload data carried by said radio signal between said source equipment or the previous relay equipment and said current relay equipment, said current intermediate delay (DTi) being a function of said current power ratio obtained, of a volume (Vol, Voli) of useful data received by said current relay equipment and of a transmission bandwidth (W, Wi) of this volume between the source equipment or the previous relay equipment and said current relay equipment;

- the estimate (EST. DTG _N ) of an overall transmission delay (DTG _N ) of the radio signal from the source equipment to a final relay equipment placed at a number N of hops, with N integer greater than or equal to i , at least from the current determined intermediate transmission delay (DTi) and from at least one previously determined intermediate delay; - if the estimated overall transmission delay reaches or exceeds a given maximum delay (DMax), modifying (MOD. CNF) a multi-hop transmission configuration of said system (10).

14. Device (200) for processing a multi-hop transmission in a wireless communication network, said transmission being implemented by a system (10) comprising a source equipment (ES) and a plurality of relay equipment of the wireless communication network, configured to receive, amplify and retransmit a radio signal emitted by the source equipment, characterized in that the said device is configured to implement, for a relay equipment (ERi) of the so-called current system, placed at i jumps of the source equipment, with i non-zero integer:

- the transmission to a control device (100) of the wireless communication network of at least one radio signal power and one noise and interference power received and measured by said current relay equipment; and

- the receipt from said control device of an action message comprising at least one modification of a multi-hop transmission configuration of said system and an order to implement said modification, said configuration modification comprising at least a maximum number of relays (NMax) greater than or equal to i and a rule for deactivating a retransmission of the radio signal received from the source equipment, and the implementation order being intended for the relay equipment located at a number of hops greater than or equal to said maximum number of relays.

15. System (10) for multi-hop transmission in a wireless communication network, comprising a source equipment (ES) configured to transmit in said network a radio signal and a plurality of relay equipment configured to receive, amplify and retransmit the radio signal transmitted by the source equipment, characterized in that the system comprises a device (100) for controlling a multi-hop transmission in accordance with claim 13 and in that the said relay equipment (ERi) comprises a device (200 ) processing said multi-hop transmission according to claim 14.