FR2954027A1 - Multi-channel radio communication network configuring method, involves constructing mesh operating on radio channel as data node, and modifying mesh based on selected relay node participating in another mesh - Google Patents

Abstract

The method involves selecting a relay node participating in a mesh, where the selected relay node adjusts a radio channel and relays data transmitted by a source node to a destination node. Specific data are received by a data node. Another mesh operating on the radio channel is constructed as the data node that relays the specific data received by the data node via another radio channel. The latter mesh is modified based on the selected relay node participating in the former mesh. Independent claims are also included for the following: (1) a computer program product comprising a set of instructions for implementing a method for configuring a multi-channel radio communication network (2) a computer readable storage unit comprising a computer program comprising a set of instructions for implementing a method for configuring a multi-channel radio communication network (3) a management node for configuring a multi-channel radio communication network.

Description

A method of configuring a multichannel radio communication network, computer program product, storage means and corresponding manager node. FIELD OF THE INVENTION The field of the invention is that of wireless networks and in particular, but not exclusively, short-range wireless networks (also called "WPAN" for "Wireless Personal Area Network" in English), which are well suited for audio / video distribution in a room. More specifically, the invention relates to a technique for configuring a multi-channel radio communication network using at least two radio channels and comprising a source node, a destination node and a plurality of relay nodes. Such a multi-channel radio communication network makes it possible in particular to support high speeds thanks to the multiplication of the radio interfaces and to the diversity of the radio channels used. BACKGROUND OF THE INVENTION In the remainder of this document, reference is made more particularly to the problematic that exists in the particular case of a "home theater" system which the inventors of the present patent application have been confronted with. The invention is of course not limited to this particular case of application, but is of interest for any configuration technique of a multi-channel radio communication network having to face a similar problem or similar. Let us consider illustratively a home theater system comprising: a high definition video source and a 5.1 audio source (source audio surround) source attached to (or integrating) an audio / video source node; a high definition screen attached to (or integrating) a video destination node; and a series of six speakers each attached to (or integrating) an audio destination node. The audio / video source nodes, video destination, and audio destination form a 60 Ghz radio communication network.

The 60 Ghz radio communication technology transports a high-definition video stream and the associated audio stream. However, this technology is sensitive to the phenomena of masking and fading ("fading" in English) of the signal. To avoid these phenomena, it is customary to use a network mesh method (or "Mesh Network" in English). Thus, to transport the audio stream from the source to each speaker, this meshing method consists of attempting to send all the audio data to each audio destination node, and to load those that correctly receive the audio stream of the audio source. retransmit while playing the role of audio relay node. The audio stream is then made more reliable. Such a method also applies to the network control data between the audio / video source nodes, the video destination and the audio destination. Of course, other types of application data than audio / video data can be exchanged between the different nodes of a multi-channel communication network, such as parameter data, digital file data (exchanges of files between computers). ), ... The reliability of the transport of the video stream is different. Indeed, for obvious reasons of need in bandwidth, it is not possible to retransmit the video data by several nodes of the network without compromising the quality of the video after decoding. Indeed, to multiply the copies of video data requires compression of the data at the source so as to respect the constraints of bandwidth of the communication network. To make video transport more reliable, it is customary to designate a limited number (see only one) relay node, also called video relay node, advantageously chosen from audio destination nodes to establish a backup path. Consider now a more advanced home theater system with a panoramic display consisting of two high-definition displays. Due to the bandwidth limit of the network, the current 60 Ghz radio technology makes it necessary to carry at least two high definition video streams (one for each panoramic display device) to use data compression at the source . In order to limit the disadvantages associated with this compression in such a bandwidth limit context, it is customary to use: a first radio channel for transporting the first video stream (with reliability based on a relay node to establish an escape route); a second radio channel for carrying the second video stream.

In this case, the audio / video source node and the video destination node are multi-radio nodes (i.e. they can simultaneously address both radio channels). The reliability of the transport of the second video stream on the second radio channel requires the presence of an additional radio interface on the relay nodes, which is expensive. Indeed, the majority of masks and fades appearing in such a system, are not predictable and, not knowing which relay node will be adapted to establish a backup path, it is necessary to equip each relay node with a dual interface radio (in order to be able to communicate on each of the two channels). In addition, it is necessary to ensure that the audio data reaches the destination audio node for which they are intended and that the control data of the communication network reaches all the nodes of said network. OBJECTIVES OF THE INVENTION The invention, in at least one embodiment, has the particular objective of overcoming these various disadvantages of the state of the art. More specifically, in at least one embodiment of the invention, one objective is to provide a network configuration technique that makes it possible to make the transport of several types of data (for example several different types of data) reliable and inexpensive. flow) in the following context: - relay nodes are set to a first radio channel; a source node transmits to a destination node first data on a second radio channel; and a first mesh operating on the first radio channel for the transmission of second data between the source node, the destination node and a plurality of nodes. At least one embodiment of the invention aims to make reliable, in the aforementioned context, to ensure the delivery (without unrecoverable errors) of the first data (for example video type) from the source node to the one node destination, in order to overcome masking and interference phenomena.

At least one embodiment of the invention aims to make reliable, in the aforementioned context, the data communications between the nodes operating on the first and second channels. At least one embodiment of the invention also aims to provide such a technique that is simple to implement and low cost. More particularly, it is desirable to provide a technique which makes it possible to limit the number of nodes having a multi-radio interface in the aforementioned context. SUMMARY OF THE INVENTION In a particular embodiment of the invention, there is provided a method of configuring a radio communication network comprising relay nodes set on a first radio channel, a source node transmitting to a node. destination of the first data on a second radio channel, a first initial mesh operating on the first radio channel for the transmission of second data, said relay nodes participating in the first mesh, this method is remarkable in that a manager node performs steps consisting of to: select one of the relay nodes participating in the first mesh, the selected relay node being such that: * the selected relay node, once set on the second radio channel, is able to relay to the destination node the first data transmitted by the node source; specific data is received by a given node, said specific data being, among the second data, data intended for the selected relay node; constructing a second mesh, operating on the second radio channel and such that the given node performs a first relay, to the selected relay node, specific data received by the given node via the first radio channel; - modify the first mesh, taking into account that the selected relay node no longer participates in the first mesh.

Thus, in this context and in order to make reliable the transport of said first data on the second radio channel, in a simple, effective and inexpensive way, the general principle of the invention is to switch one of the mono-radio relay nodes from the first main radio channel to the second radio channel, so as to make the transport of the first and second data reliable. Thus, this particular embodiment of the invention is based on a completely new and inventive approach consisting in: - making the transport of the first data more reliable on the second radio channel by creating an emergency path between the node source and the destination node via said selected relay node; - Make reliable the transport of the second data on the second mesh, thanks to the first relay of these second data performed by the given node from the first mesh (via the first to the second radio channel). By switching at least one relay node from the first radio channel to the second radio channel, a second network is created comprising at least the source node, the given node and the selected relay node.

In a particular embodiment of the invention, the source node and the destination node are multi-radio nodes, that is to say each having at least two radio interfaces for data transmission on different channels (the Figure 1 illustrates this configuration). In another particular embodiment of the invention, the source node and the destination node are not multi-radio, and only the given node (which performs the relay) is multi-radio. In this case, there are at least two pairs of source and destination nodes, each pair comprising a separate radio interface (mono-radio nodes). Advantageously, the selected relay node is further such that each node of the first modified mesh receives its specific data, among the second data, with a reception quality level higher than a predetermined threshold. Thus, all the nodes of the first modified mesh can receive all of their specific data despite the removal of the first initial mesh of said selected relay node. Advantageously, in the step of constructing a second mesh, the second mesh is further such that: the source node transmits the specific data on the second radio channel; and - the given node performs a second relay, to the selected relay node, specific data and received by the given node via the second radio channel. Thus, the second mesh is completed and therefore the transport of the second data is even more reliable. Indeed, the selected relay node can receive the second data in three ways, on the second radio channel: - directly from the source node; from the destination node, which relay data from the source node; from the destination node, which performs the first relay of data from the first radio channel. Advantageously, the first modified mesh is further such that the given node performs a third relay, to nodes participating in the first mesh, second data transmitted by the selected relay node and received by the given node via the second radio channel.

Thus, although set on the second radio channel, the selected relay node continues, thanks to the second relay, to benefit from the first mesh operating on the first radio channel, more important in comparison with the second mesh. As a result, all the nodes of the first radio channel can further receive the second data generated by the selected relay node, now using the second radio channel.

According to another advantageous characteristic, the step of selecting one of the relay nodes comprises a step of determining a set of at least one of said relay nodes such as a quality level of a radio communication link on the first channel. radio between said relay node (s) of said set and each of the source and destination nodes is greater than a predetermined threshold, said selected relay node belonging to said set. Thus, one chooses a node able to execute the relay function between the source node and the destination node with respect to the radio conditions at the instant of choice. Advantageously, said manager node performs steps of: - choosing a relay node; - send an extraction simulation command of the chosen relay node; collecting information relating to reception quality levels determined by nodes participating in the first mesh, after taking into account said extraction simulation command; the relay node selected being the chosen relay node, if according to the information collected, the first mesh remains functional. Thus, before any selection operation of a relay node, it is necessary to select a relay node whose removal of the first mesh is likely not to disrupt the operation. Advantageously, upon receipt of said extraction simulation command: the selected relay node transmits data simulating its removal from the first mesh; each other relay node participating in the first mesh determines, over a predetermined duration, a level of decoding quality, on the first radio channel, of data to be consumed by said other relay node. Thus, the validation of the selected relay node is optimized without having to extract it from the first mesh before this validation is performed, which makes it possible to maintain the current configuration of the communication network. Indeed, an effective extraction of the selected node would lead to unnecessary manipulations (introducing further processing latency) of routing tables and relay scheme. Thus, the validation of the selection is made quickly and safely.

Advantageously, if at the end of the step of selecting one of the relay nodes participating in the first mesh, no relay node is selected, the method comprises a step of replacing said first mesh with a replacement mesh, the step of selecting one of the relay nodes being performed again with said replacement mesh.

Thus, by changing the first mesh, the chances of finding and selecting a relay node that meets the aforementioned constraints are increased. In addition, the first data is video data, and the second data is audio and / or control data. Thus, the present invention is particularly applicable to a home theater configuration. Advantageously, said given node is the destination node.

Thus, it reduces to the strict minimum the number of interfaces necessary for the transmission of data on the second radio channel. More generally, it limits the number of nodes of the communication network to have several radio interfaces.

In another embodiment, the invention relates to a computer program product which comprises program code instructions for carrying out the aforesaid method (in any of its various embodiments), when said program is running on a computer. In another embodiment, the invention relates to a computer readable storage means storing a computer program comprising a set of computer executable instructions for carrying out the above method (in any one of its different embodiments). The invention also relates to a manager node capable of configuring a radio communication network comprising relay nodes set on a first radio channel, a source node transmitting to a destination node first data on a second radio channel, a first initial mesh operating on the first radio channel for the transmission of second data, said relay nodes participating in the first mesh, This manager node is remarkable in that it comprises: means for selecting one of the relay nodes participating in the first mesh, the selected relay node being such as: * the selected relay node, once set on the second radio channel, is able to relay to the destination node the first data transmitted by the source node; specific data is received by a given node, said specific data being, among the second data, data intended for the selected relay node; means for constructing a second mesh, operating on the second radio channel and such that the given node performs a first relay, to the selected relay node, of the specific data received by the given node via the first radio channel; Means for modifying the first mesh, taking into account that the selected relay node no longer participates in the first mesh. 5. LIST OF FIGURES Other features and advantages of the invention will appear on reading the following description, given by way of indicative and nonlimiting example, and the appended drawings, in which: FIG. 1 schematically illustrates an example of a home theater wireless system, in which the invention can be implemented; FIG. 2 illustrates an example of a TDMA type communication on a radio channel of the wireless communication network of FIG. 1, according to one particular embodiment of the invention; FIG. 3 illustrates an example of a default mesh matrix for the system of FIG. 1; - Figure 4 schematically illustrates a format of a data block, according to a particular embodiment of the invention; FIG. 5 schematically illustrates a transmission data path, in a mesh portion of superframe, according to a particular embodiment of the invention; FIG. 6 schematically illustrates a data path in reception, in the supertram mesh part, according to a particular embodiment of the invention; FIG. 7 schematically illustrates a data transmission path, in a point-to-point superframe part, according to a particular embodiment of the invention; FIG. 8 schematically illustrates a data path in reception, in the point-to-point part of supertam, according to a particular embodiment of the invention; FIG. 9 shows a block diagram of a communication node, according to a particular embodiment of the invention; FIG. 10 shows a block diagram of a communication controller of a mono-radio node, according to a particular embodiment of the invention; FIG. 11 shows a block diagram of a communication controller of a multi-radio node, according to a particular embodiment of the invention; FIG. 12 presents a flowchart of a starting procedure for a master node, according to a particular embodiment of the invention; FIG. 13 presents a flowchart of a starting procedure of a slave node, according to a particular embodiment of the invention; FIG. 14 is a flowchart detailing step 1202 of FIG. 12, according to a particular embodiment of the invention; FIG. 15 is a flowchart detailing step 1208 of FIG. 12, according to a particular embodiment of the invention; FIG. 16 is a flow chart detailing step 1207 of FIG. 12, according to a particular embodiment of the invention; FIG. 17 illustrates an example of a first mesh matrix obtained from the default mesh matrix of FIG. 3, by applying the algorithm of FIG. 16; FIG. 18 illustrates an example of a second mesh matrix obtained from the default mesh matrix of FIG. 3, applying the algorithm of FIG. 15. DETAILED DESCRIPTION FIG. 1 schematically illustrates an example of FIG. conventional wireless "home theater" system for projecting video in a panoramic display format (for example with a resolution of 2 * 720p) accompanied by a 5.1 multichannel audio stream, in which the technique can be implemented of the invention. The audio stream and the two video streams are generated from an audio / video server 1 (eg a multimedia PC). The video is projected by means of a pair (2, 3) of high definition video projectors (for example 720p resolution). The audio is output by a set of speakers (including speakers) 4 to 9 including a subwoofer 4, a center speaker 5, a front right speaker 6, a front left speaker 7, a rear left speaker 8 and a right rear speaker 9. The audio and video streams are transported from the audio / video server 1 to the video (2, 3) or audio (4 to 9) destinations via a 60 Ghz wireless synchronous network. This network is composed of a node mc-S 10 attached to the audio / video source 1, a node mc-R 11 attached to the two video projectors and six nodes WAS1 to WAS6 attached to the set of speakers 4 to 9. In an alternative embodiment, the audio and video sources are attached to two separate nodes, the node to which the audio source is attached may have only a radio interface 18. In order to clearly show the channel (s) used by each node, FIG. 1 shows the radio communication interfaces of the communication nodes. The mc-S node 10 has two radio communication interfaces 18 and 19. The radio interface 18 is set to operate on a first radio channel, and the second radio interface 19 is set to operate on a second radio channel. Similarly, the node mc-R 11 has two radio communication interfaces 18 and 19, identical to those of the node mc-S 10. The nodes WAS1 to WAS6 have a single radio interface, configurable to be either a radio interface 18 set on the first radio channel, a radio interface 19 set on the second radio channel. Of the WAS nodes, in Figure 1, the WAS6 node (also referred to as the D node thereafter) is configured with a radio interface 19 set to the second radio channel; the other nodes WAS1 to WAS5 are configured on a radio interface 18 set on the first radio channel. In the remainder of the description, it is considered that the node mc-R 11 is able to perform bridging relay ("bridge in English) between the first and second radio channels. It is understood that such a bridge relay can be implemented by any other relay node of the communication network. FIG. 2 illustrates an example of a TDMA-type synchronous communication on a radio channel of the 60 Ghz wireless communication network of FIG. 1, according to one particular embodiment of the invention. According to a particular embodiment of the invention, access to the communication medium is of the "TDMA" type (for "Time Division Multiple Access" or "Time Division Multiple Access"): access to the medium of communication is thus governed according to a timing (shared time access) known to all the nodes of the network. According to a particular embodiment of the present invention, the TDMA access management is performed by the node mc-S 10 which has the role of master node, the other nodes having the role of slave nodes. The time is divided into data transmission cycles (called SDTC cycles for "Synchronous Data Transmission Cycle"). A superframe is transmitted at each cycle. A superframe is a sequence of frames whose length and sender node characteristics are the same at each cycle, until the known timing of all the nodes in the network is changed. At startup, all the nodes work for example according to a predefined timing. In the embodiment illustrated below, the mc-S node 10 manages the network access and the definition of the applicable meshes on each of the first and second radio channels. In an alternative embodiment, this network management can be performed by any other node of the network. A superframe according to a particular embodiment of the present invention consists of a mesh portion 201 and a point-to-point portion 202. The frames 203, 204 of the mesh portion 201 are sent in "broadcast" mode (or broadcast "in English) by means of the radio interface of the node mc-S 10 (here in its function of master), that is to say that the transmit antennas of the node mc-S 10 (here in its master function) are in omnidirectional mode (isotropic antennas) or quasi-omnidirectional (according to a wide angular sector for example of 210 degrees). Each of the other nodes is potentially a receiver of these frames and can retransmit them in order to implement the so-called mesh method. The retransmission is also performed in an omnidirectional mode. The omnidirectional mode is particularly well suited for transporting audio data requiring little bandwidth compared to video data. The omnidirectional mode is also particularly well suited to the broadcast of control data of the communication network.

The frames 205, 206 of the point-to-point part 202 are sent in point-to-point mode (or "unicast" mode) by the radio interface of the nodes that transmit or retransmit them. That is, the transmitting antennas of the transmitting nodes are set to directional mode. The directional mode makes it possible to concentrate the energy of the transmission in one or more targeted directions. The directional mode is used for the transport of data that can not benefit from mesh techniques, typically video data. Indeed, the video data can not benefit from the mesh technique because the amounts of data are too important to be repeated several times through the network. However a small number of relays (per relay nodes) can be set up (depending on the allowed degradation of the video related to the compression of the data to meet the bandwidth constraints). Thus, several frames may be transmitted during the point-to-point portion 202 for the same data stream. The node mc-S 10 (here in its master function) always sends the first frame 203 of the superframe and thus marks the beginning of the superframe. The frames 203, 204 of the mesh portion 201 are composed of a header portion 207 conventionally comprising an issuer node identifier, and a useful portion 208, including data. The composition of the data of the useful parts 208 of the frames 203, 204 of the mesh part 201 of the super-frame is defined by a mesh matrix more fully described below in relation to FIG. 3. The frames 205, 206 of the part point-to-point 202 are composed of a header portion 209 typically comprising an issuer node identifier, and a useful portion 210, including data.

Figure 2 depicts access to a first radio channel. Access to a second radio channel is similarly shared, with a mesh portion 201 and a point-to-point portion 202, regardless of transmissions operating on the first radio channel. FIG. 3 schematically illustrates an example of a default mesh matrix (MESH # CONF) for the system of FIG. 1, before application of the algorithms of FIGS. 12 to 14 of the present invention.

Each of the nodes of the network has a copy of the same default mesh matrix making it possible to determine which data is addressed to them (either for decoding or for simple relay) among the data transmitted during the mesh portion 201 of the superframe . This default mesh matrix also makes it possible to determine to which stream and / or to which type of data is associated the content of blocks of data constituting the frames that each node sends during the mesh portion 201 of the superframe. It should be noted that it is essential that all the nodes use the same matrix of mesh for a coherent operation of the system.

The mesh matrix is in the form of a table whose columns represent blocks of data numbered from 0 to 25 for the example presented. Each frame of the superframe can therefore contain up to 25 blocks of data. The lines of this table represent the frames generated by the nodes of the network participating in the mesh (one line per node). In this example of FIG. 3 is represented the set of nodes of the wireless communication network as described with reference to FIG. 1. For each node, the default mesh matrix provides information on the use that is made of the blocks of data. In Figure 3, each box of the table; which corresponds to the use of a particular data block by a particular node contains: - "O" if that particular block is generated by that particular node; - "C" if that particular block is consumed by that particular node; - "R1" If this particular block is relayed in the same cycle by that particular node; - "R2" If this particular block is relayed in the next cycle by that particular node; In the example of FIG. 3, only the columns of the data blocks 0 to 9 and 19 to 25 are detailed for the sake of simplification. Of course, the remaining data blocks 10 to 18 (not shown) are treated analogously. Thus, for example: the node mc-S generates data blocks 0 to 9 audio and control; the node mc-R 11 generates blocks of control data 19 and relays data blocks 20 to 23 in the next cycle; the node WAS1 consumes data blocks 3, 4 and 5. It relays data blocks 0, 1 and 2 in the same cycle and the data blocks 24 and 25 in the next cycle. It also generates a control data block; the node WAS2 relays data blocks 1, 3, 5 and 7 in the same cycle and generates a control data block 21; the node WAS3 consumes a data block 9, relays data blocks 4, 6 and 8 in the same cycle, and generates a control data block 22; the node WAS4 relays the data block 9 in the same cycle, and generates a control data block 23; the node WAS5 consumes data blocks 6, 7 and 8, generates a control data block 24; the node WAS6 consumes data blocks 0, 1 and 2, relays a data block 19 in the same cycle, and generates a control data block 25. Figure 4 schematically illustrates a format of a data block as discussed in Figure 3, according to a particular embodiment of the invention. A data block is a set, for example 224 bytes, used to transport the data relating to an application flow (either during the mesh portion 201 or during the point-to-point portion 202 of the superframe). It consists of a header field 401, a data field 402 and a control field 403. The header 401 comprises a first subfield 404 (H2) comprising for example two bytes 404 reserved for future uses, and a second subfield 405 (H1) for example comprising two bytes 405 used to define the content of the data field 402. The data field 402 is organized for example in groups of twelve bytes, each being "typed By a bit of the second subfield 405 of the header field 401. For example, the first set of twelve bytes 406 is controlled by the first bit of the second subfield while the last group of twelve bytes 407 is controlled by the sixteenth bit of the second subfield. When a bit of the second subfield 405 is set to 1, this means that the corresponding twelve-byte group contains application data. If this bit is 0, then the corresponding 12-byte group contains a system code. Two different system codes are used in the context of the communication network of FIG. 1. A group of twelve bytes all at 0 means the code "NULL" ("nul" in French), and a group of twelve bytes equal to the representation hexadecimal 0x555555555555555555555555 means the code "UNKNWON" ("unknown" in French). The "NULL" code is used in transmission to indicate the absence of application data, while the "UNKNOWN" code is used in reception to indicate a lost or corrupted block of data. Finally, the redundancy field 403 serves to place the result of the calculation of a Reed Solomon encoding of the header field 401 and the data field 402. FIG. 5 schematically illustrates a path followed within the node mc-S 10. by data (such as for example audio data and control data) during their transmission for the mesh part of the superframe, according to a particular embodiment of the invention.

More precisely, this FIG. 5 illustrates a path followed within the mc-S node 10 by audio data and / or control data, that is to say the data blocks 0 to 9 in the example of FIG. Figure 3 (boxes marked "O" on the line corresponding to node mc-S 10). The audio data is acquired using a high definition multimedia interface 500 (or "HDMI" for High Definition Multimedia Interface). The HDMI 500 interface provides, for example, six 50-bit audio channels 501 of 48 bits at a rate of 48 Khz. A synchronization channel 505 is generated by the mc-S node 10. The mc-S node 10 generates synchronization information Sync for each SDTC cycle. For example, each SDTC cycle has a duration of 2 milliseconds. The synchronization information Sync thus gives a relative position of the beginning of the timing of the 48 Khz frequency clock within the SDTC cycle. A control channel 506 comprising control data is generated by a processor CPU 902 (for Central Processing Unit "in English or the central processing unit in French, hereinafter described in connection with FIG. 9) of the node mc. -S 10. The node mc-S 10 then forms groups 502 of twelve bytes, also called virtual channels (or "VC" for "Virtual Channel" in English) according to a clock clocked at 8 Khz and specific to the node mc-S 10. For each audio channel 501, the number of virtual channels that must be simultaneously filled is obtained by calculating the ratio between the audio bit rate and the bit rate of a virtual channel. In this example, the audio bit rate is 2.304 Mbps and the bit rate of a virtual channel (twelve bytes at 8 Khz) is 768 Kbps. It is therefore necessary to simultaneously fill three virtual channels per audio channel. The division is not necessarily complete, and the clocks can vary in time, it is necessary to provide a slightly higher flow in virtual channels.

In the absence of all or part of the 12 bytes, the node mc-S 10 substitutes a "NULL" code. The control channel 506 and the synchronization channel 505 are each transported in a single virtual channel. Then, data blocks 503 are constructed by accumulating the same virtual channels along the SDTC cycle. For further details regarding the construction of the data blocks, reference may be made to US2008 / 0259950. Finally, data frames 504 (or "frame" in English) are sent during the mesh portion 201 of the superframe (a header, not shown, being added to the data blocks 503 to form frames like the frames 203 or 204 of Figure 2).

FIG. 6 schematically illustrates a path followed within a node (other than the nodes mc-S 10 and mc-R 11) by data (such as for example audio data) during their reception during the mesh part of the superframe, according to a particular embodiment of the invention. At each superframe (i.e., every 2 milliseconds in the above example), data frames 504 (a header, not shown, is removed from the frames like frames 203 or 204 in FIG. to obtain the data blocks 503) are received during the mesh portion 201 of the superframe. From these frames are extracted from the data blocks 503. The matrix of FIG. 3 makes it possible to define the blocks required for reception, either to retransmit them or to extract data addressed to the local node. Each block of data may be received in multiple copies during one or more superframes. The different copies of the same block of data are combined according to, for example, an erasure technique for a "Reed Solomon" type decoding. The combination consists in making word-by-word comparisons of the different data block copies. For each word that is not identical on all copies, an erase is then set. A Reed Solomon decoder implementing the erase technique is more particularly described in US Pat. No. 5,715,262. Once the data block decoding phase has been completed, the data is either accessible (successful decoding) or replaced by "UNKNOWN" codes (decoding impossible). Then, in another time domain, for the same virtual channel (VC) 502, the same amount of data will be extracted from each data block every 125 μs corresponding (at the frequency of 8 Khz). This amount of data is defined according to the application rates. For more details on the processing of data blocks in reception, reference may again be made to patent document US2008 / 0259950. Then, in the time domain of the application, an audio sample is extracted every 20 milliseconds (frequency 48 Khz). The application clock is locally synthesized and synchronized by the time information transported in the synchronization channel 505. As described with reference to FIG. 5, the timing information of the synchronization channel gives a relative position of the source audio clock with respect to the synchronization channel. network clock of the source node. Thanks to the synchronous nature of the network, all the nodes have a synchronized network clock. Thus, by resynchronizing the application clock on their network clock, the nodes synchronize the destination application clock on the source application clock. The control data of the control channel 506 is in turn extracted from a particular virtual channel and reassembled in a RAM 903 ("RANI" for "Random Access Memory" in English or RAM in French) associated with the processor CPU 902 FIG. 7 schematically illustrates a path followed within the node mc-S 10, by data (such as for example high definition video data) for transmission during the point-to-point portion of the superframe, according to a mode of particular embodiment of the invention. The video is received through an HDMI 700 interface, thus defining a clock domain at 60 Hz (60 frames per second) or 150 Mhz (150 Mega pixels per second). The video is encoded in real time by a low latency encoder 701, and the result of the encoding is stored in data blocks 702 at a rate of 8 Khz. It is reserved a number of blocks of data corresponding to the maximum of data that the encoder can generate in 125 μs. When the encoder generates less data than the maximum possible, then the data blocks are supplemented with "NULL" codes (also called padding data). Then, in the same way as for the audio, data frames 703 are formed at each superframe (i.e., every 2 milliseconds in the above example) from the data blocks 702. frames are sent in the point-to-point portion 202 of the superframe (a header, not shown, being added to the data block 702 to form frames as the frames 205 or 206 of Figure 2). According to the same principle as for audio data, a synchronization channel 704 is allocated in order to be able to synchronize the restitution of the video on the receiver side. This synchronization channel 704 is generated by the node mc-S 10. The node mc-S 10 generates synchronization information Sync at each cycle SDTC giving a relative position of the start of the clock frequency 30Hz clock inside. of the SDTC cycle.

In the synchronization channel 704 is noted the relative position of a Vsync video signal (60 Hz) within the cycle of 125 μs (8Khz). The synchronization channel 704 is transported in a virtual channel 705 formed by the node mc-S 10 identically to the virtual channels 502 of FIG. 5, according to a clock clocked at 8 Khz and specific to the node mc-S 10. 8 schematically illustrates a track followed, within a node (the node mc-R 1 l rent one of the relay nodes WAS1 to WAS6) other than the node mc-S 10, by data (such as for example video data high definition) for their reception during the point-to-point portion 202 of the superframe, according to a particular embodiment of the invention. In the same way as for receiving the audio data, data frames 703 are received at each superframe (i.e. every 2 milliseconds in the above example) during the point-to-point portion 202 Data blocks 702 are extracted from these frames 504 (a header, not shown, is removed from the frames like the frames 205 or 206 of Figure 2 to obtain the data block 702). In the case of a relay node, the data blocks are used as such to form a new frame in order to be transmitted in the same superframe (it is recalled that it is in this case a data transmission point to point).

In the case of the mc-R 11 node, two copies of each data block are expected at each superframe. Upon receipt of the first copy, Reed Solomon decoding is performed. If the first decoding is satisfactory, then the data block is selected. Otherwise, the second copy is decoded. Once all the data blocks are received during a superframe, then the data is extracted from the blocks to feed the video decoder 801. As described in FIG. 5, the time information of the synchronization channel 704 (extracted from a channel virtual 705) give a relative position of the source video clock with respect to the network clock of the source node. Thanks to the synchronous nature of the network, all the nodes have a synchronized network clock. Thus, by resynchronizing the application clock on their network clock, the nodes synchronize the destination application clock on the source application clock. FIG. 9 shows a block diagram of a communication node, according to a particular embodiment of the invention.

A communication node is built around a synchronous communication controller 901. The synchronous communication controller is connected to the processor CPU 902, the RAM 903 and a ROM (for "Read-Only Memory" or " read-only memory "in French) 904 through a bus governed by a bus controller 905.

The synchronous communication controller is connected to application interfaces 906 to 909. A first pair of application interfaces 906 and 907 make it possible to receive and transmit a multi-channel digital audio stream with HDMI connectivity. A second pair of application interfaces 908 and 909 implement an input and a video output including a video encoder in the interface 909 and a video decoder in the interface 908. Finally, the synchronous communication controller is connected to a module MAC / radio to communicate on one or two radio channels at 60 Ghz. Two different versions of the synchronous communication controller are described below. A first version, described in connection with FIG. 10, is used in mono-radio nodes of type WAS1 to WAS6. A second version, described with reference to FIG. 11, is used by the two multi-radio nodes mc-S 10 and mc-R 11. FIG. 10 shows a block diagram of a synchronous communication controller of a mono node -radio, according to a particular embodiment of the invention.

The application data from the audio and video interfaces 907 and 909 are obtained by an AL TX 1001 module at the rate of the local clock at 8Khz. The audio data is formatted as data blocks by a MESH module TX 1002 in a DPTxl dual port memory 1003. The MAC interface TX 1004 fetches the data blocks from the memory 1003 to make frames for the part. mesh 201 of the superframe.

The video data is formatted as data blocks by a P2P TX 1005 module in a DPTx2 dual port memory 1006. The TX MAC interface 1004 draws the data blocks from the memory 1006 into frames for the dot portion. to point 202 of the supertram.

An RX MAC interface 1007 receives the frames transmitted during the mesh portions 201 and point-to-point 202 of the superframe, and received from the other nodes of the network. The frames of the mesh portion 201 are processed by a MESH RX 1009 module. The MESH RX 1009 module stores the blocks to be retransmitted in the double port memory DPReTx2 1010. The DPReTx2 memory 1010 is read by the MAC interface TX 1004 to complete the frames to be transmitted in the mesh portion 201 of the superframe. The MESH RX 1009 module also carries out Reed Solomon decoding operations on the data blocks addressed to the node in question (that is to say that must be consumed by the node considered), the result of the decoding is stored in the memory at dual port DPRxl 1013. The frames of the point-to-point portion 202 of the superframe received by the MAC interface RX 1007 are either processed by the P2P module ReTX 1008, if the node is configured as a video relay, or processed by the P2P RX 1011 module, if the considered node is a final destination for the video (i.e. if the video data is to be consumed by the considered node). The blocks of video data to be relayed are stored in the dual port memory DPReTX1 1015. The blocks of video data to be consumed by the node in question are stored in a double port memory DPRx2 1012. The blocks of audio data stored in the memory to dual port DPRxl 1013 and the video data blocks stored in the dual port memory DPRx2 1012 are consumed by an AL RX module 1014. FIG. 11 shows a block diagram of a synchronous communication controller of a multi-radio node, according to a particular embodiment of the invention.

A synchronous communication controller of a multi-radio node is constructed by combining two synchronous mono-radio node communication controllers as described in connection with FIG. 10. The MESH RX 1107 module thus corresponds to the MESH RX 1009 module and is associated with the first radio channel. Similarly, the MESH RX 1106 module corresponds to the MESH RX 1009 module; however, it is associated with the second radio channel. Two additional modules DPBrl 1102 and DPBr2 1101 are added to allow the exchange of data between the two radio channels. The DPBrl module 1102 makes it possible to transfer data received via the first radio channel, stored in the memory DPRx1 1103, to the second radio channel by sending them to the MESH TX module 1104 associated with the second radio channel. The DPBr2 module 1101 operates symmetrically to the DPBrl module to transfer data from the second radio channel to the first. Thus the DPBr2 module 1101 makes it possible to transfer data received via the first radio channel, stored in the DPRx1 memory 1108, to the second radio channel by sending them to the MESH TX module 1105 associated with the first radio channel. Figure 12 schematically illustrates an algorithm illustrating an initialization procedure (or startup) node mc-S 10, also called master node, according to a particular embodiment of the invention. This algorithm is executed by the processor CPU 902 of the node mc-S 10. During node startup, in a step 1201, the processor CPU 902 loads a default mesh matrix (MESH # CONF), as described above. in connection with FIG. 3, in the MESH TX 1105 and MESH RX 1106 modules corresponding to the first radio channel. This first mesh matrix is obtained from the ROM 904. During a step 1202, the processor CPU 902 executes a procedure for selecting a node, to switch from the first to the second radio channel, for the active relay of the video ( high definition data). The selected node, also called node D (FIG. 1), is intended to relay the video on a second radio channel and to belong to a second mesh network, represented by a dedicated mesh matrix (second mesh matrix MESH # B). For the repetition of audio and / or control data on the second radio channel, this selection procedure, more fully detailed in relation to FIG. 14, aims to find, in connection with the default mesh matrix, a node D , relay for the second radio channel such that: * the audio and / or control data to the node D are available at the node mc-R 11; the repetition scheme remains functional despite the removal of the node D from this mesh network by default. It is also necessary that the node D has a direct path to the two nodes mc-S 10 and mc-R 11. Then, in a step 1203, the success of the step 1202 is verified, that is to say that there is a node capable of relaying the video data on the second radio channel and whose deletion of the default mesh network does not prevent the resulting mesh network (hereinafter referred to as the first mesh network MESH # A) from being viable (Refer to step 1409 described below in connection with FIG. 14). If the test of step 1203 is negative, during a step 1204, the presence of other default mesh matrices is tested in ROM memory 904. It is indeed advantageous to provide several default matrices adapted to different environments.

If the test of step 1204 is negative, that is to say if all the default mesh matrices have been verified without succeeding in selecting a relay node for the second radio channel, we proceed to a step 1209 in which the treatments are terminated. Indeed, in this case, the system can not work with a relay (that is to say with at least one spare path) for the video. This information is then sent back to the user (for example with the display of an error message on the video output of node mc-R 11, so that it changes the arrangement of the different nodes. step 1204 is positive, we go to a step 1205 in which we load the new default mesh matrix, also called replacement mesh matrix, from the ROM 904.

Then, in a step 1206, a control command is sent to the other nodes of the network (that is to say the slave nodes) so that they also change the default mesh matrix. In a first embodiment, the command sent contains a replacement matrix identifier, which the slave nodes use to select a replacement mesh matrix from the default matrices available in their respective ROM 904. In a second embodiment, the default mesh matrix changes are made according to a predefined scheduling known to all the nodes. The control command is relayed according to the default mesh matrix used until then. The command provides an indication (which it may for example contain) of the superframe to which the change of mesh matrix is to take place. The step of selecting a relay node 1202 is then executed again. If the test of step 1203 is positive, that is to say if there is a relay node of the default meshed network for the active relay of the video on the second radio channel, we proceed to a step 1207 in which builds a first mesh matrix (MESH # A) by updating the default mesh matrix (MESH # CONF) associated with the first radio channel, taking into account the fact that the selected relay node is no longer part mesh network by default. This step 1207 is described in detail later in connection with FIG. 16. Then a step 1208 makes it possible to construct a second mesh matrix (MESH # B) associated with the second radio channel. This step 1208 is more fully described in detail later in connection with FIG. 15. In summary, the second mesh matrix MESH # B is constructed so that: * the audio data for node D, generated by the node mc-S 10, are relayed by the node mc-R 11; the node mc-R 11 transfers on the second radio channel audio data and / or control data intended for the node D and received via the first radio channel.

Then a step 1210 makes it possible to send the first and second mesh matrices MESH # A and MESH # B to all the nodes of the network. In the case where more than one relay node is to be selected to provide video relay alternatives on the second radio channel, the algorithm of Fig. 12 is reiterated starting from step 1202, taking as the default matrix the current MESH # A matrix and constructing the MESH # B matrix taking into account the current MESH # B matrix. FIG. 13 presents a flowchart of a starting procedure of the slave nodes mc-R 11 and WAS1 to WAS6, according to a particular embodiment of the invention. As for the master node mc-S 10, the slave node starts in a step 1301 by loading a default mesh matrix (MESH # CONF), as described in connection with FIG. slave is one of the mono-radio nodes WAS 1 to WAS 6, it loads this default mesh matrix from the ROM 904 in the modules MESH Tx 1002 and MESH Rx 1009. If the slave node is the multi-radio node mc-R 11, it loads this default mesh matrix from the ROM 904 in the modules MESH Tx 1105 and MESH Rx 1106 of the part managing the first radio channel.

Then in a step 1302, the slave node waits for a control command from the master node mc-S 10, for a possible change of default mesh matrix. In a next step 1303, the slave node processes this control command, that is, it tests whether or not there is a default matrix change decided by the master node. Upon receipt of a control command indicating a default matrix change (positive test in step 1303), the slave node loads a new default mesh matrix in a step 1305. Then the slave node again executes step 1302.

If no mesh matrix change command is received after a predefined time (test of the negative step 1303), in a step 1305, the slave node waits for reception of a first matrix of mesh MESH # A for the first radio channel.

Once the first mesh matrix MESH # A has been received, during a step 1306, the slave node waits for the second mesh matrix MESH # B for the second radio channel. Once the second mesh matrix MESH # B has been received, during a step 1307: if the slave node is a mono-radio node of the first mesh matrix MESH # A, it loads this matrix MESH # A in the modules MESH Tx 1002 and MESH RX 1009; if the slave node is a mono-radio node of the second mesh matrix MESH # B, it loads this second matrix in the modules MESH Tx 1002 and MESH RX 1009, then sets the radio frequency of its wireless module 910 on the frequency of the second radio channel; if the slave node is the node mc-R 11, it loads the first mesh matrix MESH # A in the MESH modules Tx 1105 and MESH RX 1106, and the second mesh matrix MESH # B in the MESH modules Tx 1104 and MESH RX 1107.

Fig. 14 is a flowchart detailing step 1202 of Fig. 12 for designating the active relay node of the video (node D) on the second radio channel, according to a particular embodiment of the invention. In a first step 1401, the master node, that is to say the node mc-S 10 sends a scan request (or "scan request" in English). This request is intended for the node mc-R 11. This scanning operation is executed by both the master node, that is to say the node mc-S 10, and by the node mc-R 11. This technique said scan ("scan" in English) is well known in the business of wireless communications and is to vary the angle of orientation (or "beam steering" in English) of the antenna in reception (directional beam) and perform an RSSI (or "RSSI") measurement for "Received Signal Strength Indication" for each orientation tested. Thus, during a step 1402, the master node mc-S 10 retrieves the results of its own RSSI measurements as well as that returned by the node mc-R 11. Then in a step 1403, the master node mc-S 10 creates a set of nodes set # 1 such that the nodes of the set set # 1 satisfy the following condition: * the quality of the radio link between the nodes of the set set # 1 and each of the nodes mc-S 10 and mc- R 11 is beyond a threshold representative of good radio communication. These nodes are therefore able to relay video data transmitted by the node mc-S 10 to the destination node mc-R 11. Advantageously, the nodes of the set set # 1 further verify the following conditions * the angle formed between the orientation of the transmit antenna of the node mc-R 11 to each of the nodes of the set set # 1 and the orientation of the transmitting antenna of the destination node mc-R 11 to the node mc-S 10 is greater than a given threshold; the angle formed between the orientation of the transmitting antenna of the node mc-S to each of the nodes of set set # 1 and the orientation of the transmitting antenna of node mc-S 10 to destination node mc-R 11 is greater than this given threshold. Respecting this given threshold makes it possible to ensure that the nodes of the set set # 1 offer a relay path between the node mc-S 10 and the destination node mc-R 11 sufficiently different from the direct path between the node mc- S 10 and the destination node 25 mc-R 11, so as to ensure that the relay path provides an effective alternative to the direct path in case of masking occurring on the direct path. Information representative of the set set # 1 is then sent to the node mc-R 11. Upon receipt of the information representative of the set set # 1 by the node mc-R 11, the node mc-R 11 builds a subset of nodes set # 2 from the set of nodes set # 1. For each node in set # 1 node set, node mc-R 11: * gets the list of data blocks whose set node # 1 is the final consumer (information available in the mesh matrix) ; * interrogates the MESH RX 1106 module on the presence of these data blocks in reception. If the data blocks are present then the node of the set set # 1 is added to the set set # 2 Then the node mc-R 11 sends information representative of the set set # 2. This information is received by the master node, that is to say the node mc-S 10, during a step 1404. A next step 1405 makes it possible to test whether the set set # 2 is empty. If the test in step 1405 is positive, then the procedure for selecting a video relay node failed. A step 1406 then makes it possible to stop the procedure. If the test in step 1405 is negative, there is a set of one or more nodes that: * have a direct radio link to both mc-R 10 and mc-S 11, and * are physically far from the path direct between mc-S 10 and mc-R 11, and * are consumers of blocks of data available from node mc-R 11.

The following steps 1407, 1408, 1409 and 1410 make it possible to select, from among the nodes of the set of nodes set # 2, the one or those which, once extracted from the default mesh, must (must) be set ( s) on the second radio channel to be the relay (s) of the second video stream (the one transmitted on the second radio channel). It is then necessary to check that each node of the future first mesh (defined by the first mesh matrix MESH # A) can receive, with a reception quality level higher than a predetermined threshold, all of its data (audio and / or control) despite the disappearance of one or more node (s) of the default mesh (defined by the mesh matrix default MESH # CONF), so that the future first mesh remains functional after a withdrawal, the first default mesh of said selected relay node.

Thus, step 1407 makes it possible to select a node from the set of nodes set # 2. Then an extraction simulation command (or withdrawal) of the selected node is sent. On receipt of this command, the selected node replaces in its frames all blocks of data with blocks of data containing the code "UNKNOWN", thus simulating its disappearance in the default mesh. The other nodes receiving this command begin to evaluate for a predetermined duration the quality of the data of which they are final consumers. The quality of the received data is measured at the "UNKNOWN" code reception rate delivered by the MESH RX1009 module, that is to say the number of errors that could not be corrected during the decoding (type " Reed Solomon "). In step 1408, the node mc-S 10 collects from the nodes of the network the quality results of the data consumed. Step 1409 judges whether the default meshed network, amputated from the selected node extracted in step 1407, is viable, i.e., all nodes returned positive results in step 1408. According to a particular embodiment of the invention, a node of the first mesh having returned a positive result corresponds to a node whose level of quality of reception of its data is sufficient to continue correctly decoding the data intended for it. (no persistent errors following Reed-Solomon decoding). If the test of step 1409 is positive, then the node selected in step 1407, also called "node D", is actually selected in a step 1410. If the test of step 1409 is negative, the step 1405 is again executed with a set of nodes set # 2 no longer containing the node previously selected in step 1407. FIG. 15 illustrates a flowchart detailing step 1208 of FIG. 12, according to a particular embodiment of FIG. the invention. In a first step 1501, the second mesh matrix MESH # B is initialized by copying the default mesh matrix of FIG. 3 (which was also used to construct the first mesh matrix MESH # A (step 1207 of Figure 12)). Then, in a step 1502, one deletes from the second mesh matrix MESH # B all the lines relating to the mono-radio nodes associated with the first radio channel. In FIG. 18, the second mesh matrix MESH # B thus no longer contains data on the lines relating to the nodes WAS2 to WAS6. At the end of this step, therefore, there remains in the second mesh matrix MESH # B only the nodes mc-S 10, mc-R 11 and the node D selected in step 1410 (that is, say the node WAS1).

Then, in a step 1503, lines relating to nodes mc-S 10, mc-R 11 and node WAS 1 (node D) are removed, the reference to the data blocks consumed by the mono-radio nodes of the MESH matrix. #A, that is to say the data blocks 0, 1, 2 and 6 to 9 of FIG. 3. In a step 1504, is added to the line relating to the node mc-R 11 a code "R 2 To indicate the relay of the data blocks to the relay node selected for relaying the video data (node D, WAS1) transiting on the second radio channel. This step ends up establishing a mesh diagram on the second radio channel, to supply audio data to the selected relay node. Thus, on the line relating to the node mc-R 11, in the second mesh matrix of FIG. 18, the code "R2" is added to the data blocks 3 to 5. This code "R2" means that the data 3 at 5 are relayed by the node mc-R 11 in the next cycle. Then, in a step 1505, is added on the line corresponding to the node mc-R 11 relay data blocks received on the first radio channel and consumed by the node D. It is noted that among the data consumed by the node D includes the control data generated by all the nodes of the network. In this case, a code "B3" (for "bridged" in English or "bridge" in French) indicates that the data blocks to the node D will be those received on the first radio channel. This step increases the reliability of the mesh scheme defined in step 1504.

Thus, in the second mesh matrix MESH # B of FIG. 18, the code "B3" is used for the data blocks 3, 4 and 5 appearing as data blocks consumed by the node D in the matrix of mesh by Figure 3 defaults. This code "B3" on data blocks 3, 4 and 5 means that this data is relayed (by bridge) from the first radio channel to the second radio channel, for example on the second cycle. after the current cycle. In a step 1506, a control data relay scheme is constructed from the other nodes WAS2 to WAS6 of the first mesh (defined by the first mesh matrix MESH # A).

In the present example, the node mc-S 10 repeats the cycle following the control data blocks 19 and 20 of the node mc-R 11 and the node D previously selected in step 1410. A code "R2" is in this case used on the data blocks 19 and 20, on the line relating to the node mc-S 10 of the second mesh matrix MESH # B.

Likewise, the node mc-R 11 relays the control data of the node mc-S 10 and of the node D. Thus, on the line relating to the node mc-R 11 in the second mesh matrix MESH # B of FIG. a code "R2" on the data blocks 3 to 5 and on the data block 20 is applied for the respective relay of the control data of the node mc-S 10 and the node D.

Finally, the node D (WAS1) relays the control data of the node mc-R 11 in a following cycle. The code R2 therefore appears on the line relating to the node WAS 1, for the data block 19 of the node mc-R 11. Figure 16 illustrates a flowchart detailing step 1207 of Figure 12, according to a particular embodiment of the invention.

In a first step 1601, the first mesh matrix MESH # A is initialized by copying the default mesh matrix of FIG. 3 (MESH # CONF). In a step 1602, the line relating to the selected mono-radio node (node D) is deleted from the MESH # A matrix for relaying the video data on the second radio channel. At the end of this step, the node D selected in step 1410 is no longer present in the first mesh matrix MESH # A.

A step 1603 makes it possible to take into account that the data blocks consumed by the node D are retransmitted on the second radio channel by the destination node mc-R 11. It is therefore not necessary for the destination node mc-R 11 to relay these blocks of data on the first radio channel. In this step 1603, therefore, the reference to the data blocks consumed by the node D is deleted from the line relating to the node mc-R 11. Then, in a step 1604, the references to the data blocks generated are deleted from all the lines. (code "O") by the node D. Finally, in a step 1605, is added on the line relating to the node mc-R 11 relay (bridge) on the first radio channel control data blocks generated and transmitted by the node D on the second radio channel. Thus, all the nodes of the first radio channel can receive the control data generated by the node D, now using the second radio channel. In this case, the code "B3" is again used to indicate that the data blocks are received via the second radio channel and relayed on the first radio channel. In the example of FIG. 17, the code "B3" is inserted for the data block 20 generated by the node D (the node WAS1), which means that this data block 20 undergoes a relay operation (by bridge ) from the second radio channel to the first radio channel for example on a second cycle following the current cycle.

Once all the steps of FIG. 16 have been performed, the first mesh matrix MESH # A of FIG. 17 allows the first associated network using the first radio channel to transport the audio data reliably and efficiently, despite the fact that removing a node from the first radio channel.

Claims (1)

REVENDICATIONS1. A method of configuring a radio communication network comprising relay nodes set on a first radio channel, a source node transmitting to a destination node the first data on a second radio channel, a first initial mesh operating on the first radio channel for the first radio channel transmission of second data, said relay nodes participating in the first mesh, characterized in that a manager node performs steps consisting of: selecting one of the relay nodes participating in the first mesh, the selected relay node being such that: selected, once set on the second radio channel, is able to relay to the destination node the first data transmitted by the source node; specific data is received by a given node, said specific data being, among the second data, data intended for the selected relay node; constructing a second mesh, operating on the second radio channel and such that the given node performs a first relay, to the selected relay node, specific data received by the given node via the first radio channel; - modify the first mesh, taking into account that the selected relay node no longer participates in the first mesh. Method according to claim 1, characterized in that the selected relay node is further such that each node of the first modified mesh receives its specific data, among the second data, with a reception quality level higher than a predetermined threshold. 3. Method according to any one of claims 1 and 2, characterized in that in the step of constructing a second mesh, the second mesh is further such that: - the source node transmits the specific data on the second channel radio; and - the given node performs a second relay, to the selected relay node, specific data and received by the given node via the second radio channel. Method according to one of claims 1 to 3, characterized in that the first modified mesh is further such that the given node performs a third relay, to nodes participating in the first mesh, second data transmitted by the selected relay node and received by the given node via the second radio channel. 5. Method according to claim 2, characterized in that the step of selecting one of the relay nodes comprises a step of determining a set of at least one of said relay nodes such as a quality level of a link of radio communication on the first radio channel between said relay node (s) of said set and each of the source and destination nodes, is greater than a predetermined threshold, and in that said selected relay node belongs to said set. 6. Method according to claim 5, characterized in that said manager node performs steps of: - choosing a relay node; - send an extraction simulation command of the chosen relay node; collecting information relating to reception quality levels determined by nodes participating in the first mesh, after taking into account said extraction simulation command; and in that the relay node selected is the relay node chosen, if according to the information collected, the first mesh remains functional. 7. Method according to claim 6, characterized in that upon receipt of said extraction simulation command: the selected relay node transmits data simulating its removal from the first mesh; each other relay node participating in the first mesh determines, over a predetermined duration, a level of decoding quality, on the first radio channel, of data to be consumed by said other relay node. 8. Method according to any one of claims 1 to 7, characterized in that, if at the end of the step of selecting one of the relay nodes participating in the first mesh, no relay node is selected, the method comprises a step of replacing said first mesh with a replacement mesh, and in that the step of selecting one of the relay nodes is performed again with said replacement mesh. Method according to any one of claims 1 to 8, characterized in that the first data is video data, and that the second data is audio and / or control data. 10. Method according to any one of claims 1 to 9, characterized in that said given node is the destination node. 11. Computer program product, characterized in that it comprises program code instructions for implementing the method according to at least one of claims 1 to 10, when said program is executed on a computer. A computer-readable storage medium storing a computer program comprising a set of instructions executable by a computer for implementing the method according to at least one of claims 1 to 10. A manager node capable of configuring a network radio communication device comprising relay nodes set on a first radio channel, a source node transmitting to a destination node first data on a second radio channel, a first initial mesh operating on the first radio channel for transmitting second data, said nodes relay participating in the first mesh, characterized in that it comprises: means for selecting one of the relay nodes participating in the first mesh, the selected relay node being such that: the selected relay node, once set on the second radio channel , is able to relay to the destination node the first data transmitted by the source node; specific data is received by a given node, said specific data being, among the second data, data intended for the selected relay node; means for constructing a second mesh, operating on the second radio channel and such that the given node performs a first relay, to the selected relay node, of the specific data received by the given node via the first radio channel; means for modifying the first mesh, taking into account that the selected relay node no longer participates in the first mesh.