Method for routing messages in a mesh network

Abstract

The present disclosure relates to a routing method for routing a message (3) via nodes (2) in a network (1), wherein the message (3) comprises geographical destination data, and the method, carried out by a current node in the network (1), involves: - upon reception of a message that contains said geographical destination data and originates from an origination node, - deciding to transmit or not to transmit the message according to a desired direction of transmission of the message determined on the basis of the geographical destination data and of a direction taken by the message between the origination node and the current node.

Description

Description Title of the invention: Method for routing messages in a mesh network Technical field

[0001] The present disclosure relates to the field of message routing in a network, and in particular to message routing in a mesh network implementing a flooding transmission mode. Prior art

[0002] In IoT (Internet of Things) networks, it is known to use mesh networks, also known as mesh networks. In a mesh network, nodes are connected peer-to-peer without a central hierarchy, each node being able to receive, send, and retransmit a message. Implementing a mesh network increases the robustness of the network by avoiding hotspots, which, in the event of a failure, can hinder the operation of the network. Indeed, in a mesh network, if a node fails, the message can be transmitted via an alternative route.

[0003] Within such a mesh network, messages can be transmitted using a flooding method, commonly referred to as "flooding" in English. Flooding consists of flooding the network with messages in the hope that they will arrive at their destination. This technique can be used for message routing, or for route discovery in the network, for example according to the AODV protocol ("Ad hoc On Demand Distance Vector"). This network flooding technique eliminates the need to maintain routing tables and allows for responsiveness to changes in network architecture, for example in the case of the addition of a new node, the implementation of mobile nodes, or in the event of a failure and / or attack.

[0004] However, the flooding transmission method in a mesh network has the disadvantage of promoting network congestion and can have a significant energy impact. Routing methods are being sought that are less energy-intensive and that limit the risks of network saturation. Summary

[0005] This disclosure improves the situation.

[0006] A routing method is provided for routing a message through nodes of a network, in which the message comprises geographic destination data, and the method, implemented by a current node of the network, comprises: - upon receipt of a message including said geographic destination data, and originating from a transmitting node, - decide whether or not to transmit the message based on a desired direction of message transmission determined based on the geographic destination data and a direction taken by the message between the sending node and the current node.

[0007] "Geographic destination data" means data that allows a message destination to be located in space. "Direction" means a direction in space between the geographical locations concerned.

[0008] The use of the geographic destination data advantageously allows for geographic routing of messages. The method according to the present disclosure advantageously allows for retransmission of only messages spatially oriented towards the destination. This improves the security of message transmission because the messages are transmitted more selectively towards the destination. Indeed, the fact of not broadcasting messages unnecessarily, in particular towards the wrong directions, improves the security of message transmission. In addition, the method makes it possible to limit the number of message retransmissions before arrival at the destination. This makes it possible, on the one hand, to limit network saturation by reducing the wave effect, and on the other hand, to limit the consumption of the various network elements and therefore to reduce the energy impact of message transmission.

[0009] A geographic location is associated with each of the nodes. Each of the nodes in the network is notably aware of its geographic location determined by the node itself or transmitted by the network. The geographic location of each of the nodes may notably comprise spatial coordinates of a point associated with the node, for example a set of three-dimensional coordinates of said point. Each of the sets of three-dimensional coordinates may be associated with a radius of uncertainty around this point. Each of the nodes may comprise means for determining its location, for example geolocation means such as triangulation.

[0010] The features set out in the following paragraphs may, optionally, be implemented, independently of each other or in combination with each other:

[0011] The geographic destination data may include a destination point with spatial coordinates, to which a tolerance radius may be associated. The destination node(s) then correspond to the nodes located within the tolerance radius around the destination point.

[0012] Advantageously, the method comprises: - determining the desired direction of transmission of the message including the determination of a destination vector collinear with the direction connecting the geographical location of the current node and the geographical destination, - determine the direction taken by the message including obtaining an arrival vector collinear with the direction connecting the geographical location of the current node and the geographical location of the transmitting node.

[0013] Advantageously, deciding whether or not to transmit the message includes comparing a retransmission angle, determined as a function of the arrival vector and the destination vector, with a routing angle.

[0014] The routing angle can be fixed or adapted depending on the network topology, for example depending on the extent and / or density of the network.

[0015] Optionally, the routing angle is a constant.

[0016] Optionally, the routing angle is a piece of data that can be determined based on at least one routing parameter carried by the message. This characteristic makes it possible to further constrain the transmission of the message as it moves through the network. In other words, the message is transmitted in an increasingly selective manner as it gets closer to the destination.

[0017] Optionally, the message can carry the geographic location of the sending node.

[0018] Optionally, the message carries an address of the sending node and the current node comprises a table, called the neighbor table, listing neighboring nodes of the current node, each neighboring node being identified by an address and each neighboring node being associated with data relating to the geographical location of the respective neighboring node. The term "neighboring nodes" refers to the nodes that can directly communicate with the current node. The arrival vector is obtained according to the neighbor table when the address of the sending node is present in the neighbor table. The neighbor table advantageously makes it possible to construct a topology for routing messages by a current node according to the neighboring nodes of this current node. The term "routing topology" refers in particular to the set of admissible directions for retransmission of a message by the current node according to the geographical position of the neighboring nodes of the current node.

[0019] The data relating to the geographical location of the respective neighbouring node may consist of a geographical location of the neighbouring node or alternatively may correspond to a vector collinear with the direction connecting the geographical location of the current node and the geographical location of the neighbouring node. Storing said vector associated with the neighbouring node advantageously makes it possible to avoid calculating the vector between the sending node and the current node at each new transmission of a message.

[0020] Advantageously, the sending node is the last node to have transmitted the message to the current node. The last node to have transmitted the message to the current node is understood to mean the node that last transmitted the message to the current node in a message transmission chain.

[0021] Advantageously, the message includes a number of hops and the decision to transmit or not to transmit the message is further made based on the number of hops.

[0022] When the message comprises a number of hops, the method can advantageously be implemented as soon as the number of hops of the message reaches a predetermined number of hops since the first transmission of the message, for example two hops. In other words, the method further comprises, upon receipt of the message and prior to the implementation of the transmission of the message, the verification of the number of hops made by the message prior to the reception of the message by the current node. When the number of hops made is equal to a predetermined number of hops, the transmission of the message according to the method of the present disclosure is implemented. This makes it possible to avoid being too restrictive from the initial transmission of the message and to be able, for example, to circumvent potential obstacles.

[0023] The message may advantageously include an age and the decision to transmit or not transmit the message is made based on the age of the message.

[0024] According to another aspect, there is provided a node of a network for the method as previously described.

[0025] According to another aspect, there is provided a computer program comprising instructions for implementing all or part of a method as defined herein when such program is executed by a processor. According to another aspect, there is provided a non-transitory, computer-readable recording medium on which such a program is recorded. Brief description of the drawings

[0026] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analyzing the attached drawings, in which: Fig. 1

[0027] [Fig.l] shows an example of a network of nodes for implementing the above method, according to one embodiment. Fig. 2

[0028] [Fig.2] shows an example of steps of the method as defined above, according to one embodiment. Fig. 3

[0029] [Fig.3] shows an example of steps of the method as defined above, according to one embodiment. Fig. 4

[0030] [Fig.4] illustrates two examples A and B of routing topology of a common node for the implementation of the above method, according to one embodiment. Fig. 5

[0031] [Fig.5] shows an example of steps of the method as defined above, according to one embodiment. Fig. 6

[0032] [Fig.6] schematically illustrates a node according to one embodiment. Description of the embodiments

[0033] Reference is now made to [Fig. 1] schematically representing a network 1 having nodes 2, also conventionally designated "hosts". We are particularly interested in the routing of messages in such a network 1. A geographical location is associated with each of the nodes. Each of the nodes of the network is in particular aware of its geographical location. The geographical location of each of the nodes may in particular comprise spatial coordinates of a point associated with the node, for example a set of three-dimensional coordinates of said point. Each of the sets of three-dimensional coordinates may be associated with a radius of uncertainty around this point. Each of the nodes may comprise means for determining its location, for example geolocation means such as triangulation.

[0034] According to one aspect, the present disclosure relates to a routing method for routing a message, also referred to as a packet, via network nodes. The message comprises a geographic destination data LocDest. The message is conventionally formed of data, referred to as "payload" in English and corresponding to the content of the message to be transmitted, and routing data, referred to as "routing data" in English, allowing the management of the routing of the message in the network. Here, we are more particularly interested in the routing data of the message comprising said geographic destination data LocDest.

[0035] More precisely, the message is routed from a source S to a destination D. The “source” of the message may correspond to a node of the network, to an entity connected to one of the nodes of the network and requesting it to transmit the message. For example, a user may connect to a node through a smartphone interface. “Destination” means a geographical destination which is represented by the geographical destination data, and which may cover one or more destination nodes. The geographical destination data may comprise a destination point having spatial coordinates, to which a tolerance radius may be associated. The destination node(s) then correspond to the nodes located within the tolerance radius around the destination point. The use of the geographical destination data advantageously makes it possible to carry out geographical routing of the messages. “Geographic routing” means routing in the message space.

[0036] [Fig.2] represents a schematic diagram of the process implemented by a common node of the network. The process comprises: - upon receipt El of a message comprising said geographic destination data LocDest, and originating from a transmitting node, - decide E4 to transmit or not to transmit the message according to a desired direction of transmission of the message determined according to the geographic destination data LocDest and a direction taken by the message between the sending node and the current node.

[0037] "Direction" means a direction in space between the relevant geographical locations.

[0038] The method according to the present disclosure advantageously makes it possible to retransmit only messages that are spatially oriented towards the destination. This makes it possible to improve the security of message transmission because the messages are transmitted more selectively towards the destination. Indeed, the fact of not broadcasting messages unnecessarily, in particular towards the wrong directions, makes it possible to improve the security of message transmission. In addition, the method makes it possible to limit the number of message retransmissions before arrival at the destination. This makes it possible, on the one hand, to limit network saturation by reducing the wave effect, and on the other hand, to limit the consumption of the various network elements and therefore to reduce the energy impact of message transmission.

[0039] The determination of the direction taken and the desired direction can be carried out directly by the current node, or alternatively by a computer with which the current node is in communication for example.

[0040] The sending node is preferably the last node to have transmitted the message to the current node. The last node to have transmitted the message to the current node is the node that transmitted the message to the current node last in a message transmission chain. Alternatively, the sending node may correspond to a node that sent the message to the current node via at least one other node. The sending node may, for example, correspond to a source node of the message. It can be noted that the further upstream the sending node is taken in the message transmission chain, the more accurate the estimation of the direction taken will be. However, using the last node to have transmitted the message as the sending node is a pragmatic and simple solution to implement.

[0041] Furthermore, with reference to [Fig.3], the method advantageously comprises: - determine E2 the desired direction of transmission of the message, - determine E3 the direction taken by the message.

[0042] With reference to [Fig.1], determining the desired direction of transmission of the message may include the determination of a destination vector VecDest based on the geographic location LocNode of the current node and the geographic destination LocDest. The destination vector VecDest is in particular determined so as to be collinear with the direction connecting the geographic location LocNode of the current node and the geographic destination LocDest.

[0043] The direction taken by the message between the sending node and the current node is notably determined based on the geographic location LocSender of the sending node and the geographic location LocNode of the current node. More precisely, determining the direction taken by the message may comprise obtaining an arrival vector VecArr collinear with the direction connecting the geographic location LocNode of the current node and the geographic location LocSender of the sending node.

[0044] For this purpose, the message can carry the geographical location LocSender of the sending node. Said arrival vector VecArr can be calculated each time a message is transmitted to the current node by a sending node.

[0045] Alternatively, with reference to Figures 4A and 4B, the message may comprise an address of the sending node and the current node may comprise a table listing neighboring nodes to the current node, called the neighbor table ListNdDist. The term “neighboring node” refers to the nodes that can communicate directly with the current node. Each of the nodes in the neighbor table may be identified by an address NdDist. Each neighbor node is associated with data relating to the geographical location of the respective neighbor node. If the address of the sending node is present in the neighbor table, then the arrival vector VecArr is obtained based on the neighbor table ListNdDist. More precisely, the arrival vector VecArr is obtained based on the data relating to the geographical location of the neighbor node corresponding to the sending node.

[0046] The neighbor table thus makes it possible to construct a message routing topology for a current node based on the nodes neighboring this current node. In particular, by routing topology, we mean the set of admissible directions for retransmitting a message by the current node based on the geographical position of the nodes neighboring the current node.

[0047] Parts A and B of [Fig.4] represent two examples of parts of a network comprising nodes 2 including a current node and neighboring nodes, namely three neighboring nodes for [Fig.4]-A and two neighboring nodes for [Fig.4]-B. The said set of admissible directions are represented in hatched areas 4. With reference to [Fig.4]-A, the desired direction of transmission of the message is compatible with the routing topology of the current node, the message can be transmitted to the neighboring node concerned. With reference to [Fig.4]-B, the desired direction of transmission of the message is incompatible with the routing topology of the current node, the message is not forwarded.

[0048] In addition, the data relating to the geographical location of the respective neighboring node may consist of a geographical location of the neighboring node LocDist or may correspond to a vector VecToDist collinear with the direction connecting the geographical location LocNode of the current node and the geographical location of the neighboring node.

[0049] Storing the said VecToDist vector associated with the neighboring node is preferred because this solution avoids calculating the vector between the sending node and the current node each time a message is transmitted. Indeed, if the address of the sending node is present in the neighbor table, then the arrival vector VecArr is taken equal to the VecToDist vector associated with the neighboring node corresponding to the sending node.

[0050] The neighbor table can be built and updated incrementally, as the current node receives messages from neighboring nodes.

[0051] The neighbor table can be used directly, or only used after a certain number of neighboring nodes are listed in the current node's neighbor table.

[0052] Furthermore, [Eig.5] represents an example of steps for implementing the decision step E4. The current node determines in step E41 a retransmission angle AngleVec as a function of the arrival vector VecArr and the destination vector VecDest. In step E42, the current node then compares this retransmission angle AngleVec with a routing angle AngleRouting, and based on this comparison, it is decided whether or not to transmit the message (in particular if the retransmission angle is greater than the routing angle as detailed later).

[0053] The arrival vector VecArr can be obtained by the current node based on the geographic location LocNode of the current node and the geographic location LocSender of the sending node, when the message carries the geographic location LocSender of the sending node.

[0054] When the current node includes the neighbor table ListNdDist and the message carries the address NdDist of the sending node, the arrival vector VecArr is obtained based on the data relating to the geographical location of the corresponding neighbor node NdDist. As a reminder, this data can correspond to the geographical location of the neighbor node LocDist or can correspond to the vector VecToDist collinear with the direction connecting the geographical location LocNode of the current node and the geographical location of the neighbor node LocDist.

[0055] The re-emission angle AngleVec can in particular consist of an angle between the arrival vector VecArr and the destination vector VecDest, the arrival vector VecArr being obtained according to one of the means described previously. The determination of the re-emission angle AngleVec can be carried out by a scalar product which is a simple operation and inexpensive to carry out.

[0056] In particular, if the retransmission angle AngleVec is greater than or equal to the routing angle AngleRouting, the message is retransmitted by the current node. Conversely, if the retransmission angle AngleVec is less than the routing angle AngleRouting, the message is not retransmitted by the current node. This avoids transmitting the message to nodes that are not located in the direction of the destination relative to the current node and therefore limits or even does not saturate the network at all. In addition, this solution offers the advantage of allowing energy savings and ensuring network availability.

[0057] When the current node includes the neighbor table ListNdDist, the forwarding angle AngleVec can be determined for each neighbor node NdDist listed in the neighbor table ListNdDist. When, for one of the neighbor nodes NdDist, the current node decides to forward the message following the comparison of the forwarding angle AngleVec with the routing angle AngleRouting, said neighbor node NdDist is added to a list of selected nodes ListNdSel. More precisely, when the forwarding angle AngleVec is greater than or equal to the routing angle AngleRouting for the respective neighbor node, this neighbor node NdDist is added to a list of selected nodes ListNdSel.

[0058] Then, the message is transmitted for all neighboring nodes in the selected node list ListNdSel. This feature improves the efficiency of message processing by, when appropriate, first selecting the neighboring nodes to which the message will be transmitted, and then sending the messages to the selected neighboring nodes.

[0059] The routing angle AngleRouting is set or adapted depending on the network topology, for example, depending on the network size and / or density. The routing angle AngleRouting may have a different value for different nodes in the network, or alternatively have the same value for all nodes in the network.

[0060] In addition, the routing angle AngleRouting may in particular be a constant datum at each node or may be a determinable datum based on at least one routing parameter, in particular carried by the message. To this end, the current node may comprise a function EctAngleRouting capable of determining the routing angle AngleRouting.

[0061] For example, the routing angle AngleRouting can be determined based on a number of hops NbHop of the message. For this purpose, the message can carry the parameter of the number of hops NbHop. The number of hops NbHop can be initialized to 0 or alternatively to a maximum number of hops. Then, the number of hops NbHop can be respectively incremented by 1, or decremented by 1 each time the message is retransmitted by a node. In particular, the larger or smaller the number of hops NbHop is, the more the routing angle AngleRouting can be reduced accordingly. This characteristic makes it possible to further constrain the transmission of the message as it progresses through the network. In other words, the message is transmitted in an increasingly selective manner as it gets closer to the destination.

[0062] The routing angle AngleRouting can for example be initially set to 90°.

[0063] Additionally, additional constraint parameters can be implemented to influence the transmission of said message.

[0064] When the message includes a number of hops NbHop, the node can decide whether or not to forward the message further depending on the number of hops.

[0065] For example, when the hop count NbHop is initialized to 0, the hop count can be compared to a maximum hop count NbHopMax, for example carried by the node or directly in the message. As long as the hop count NbHop associated with the message is less than the maximum hop count NbHopMax, the message can be forwarded by the current node, otherwise the message is ignored. Alternatively, when the hop count NbHop is initialized to a maximum hop count, as long as the hop count NbHop is not zero the message can be forwarded by the current node, otherwise the message is ignored.

[0066] When the message comprises a number of hops NbHop, the method according to the present disclosure can advantageously be implemented as soon as the number of hops NbHop of the message reaches a predetermined number of hops since the first transmission of the message, for example two hops. In other words, the method further comprises, upon receipt of the message and prior to the implementation of the transmission of the message, the verification of the number of hops made by the message prior to the reception of the message by the current node. When the number of hops made is equal to a predetermined number of hops, the transmission of the message according to the method of the present disclosure is implemented. This makes it possible to avoid being too restrictive from the initial transmission of the message and to be able, for example, to circumvent potential obstacles.

[0067] Each of the nodes can advantageously include a clock, in particular a synchronized clock. The clock makes it possible to implement a parameter constraining the lifetime of the message. In particular, the message can include an age AgeMsg. The decision to transmit or not to transmit the message is notably made according to the age of the message AgeMsg. More precisely, we define a duration of lifetime AgeLimit carried by the message or specified in the current node. The age of the message AgeMsg is then compared to the lifetime AgeLimit. As long as the age of the message AgeMsg is less than the lifetime AgeLimit, the message can be forwarded by the current node, otherwise the message is ignored.

[0068] The message may also include a parameter relating to the urgency of the message. If the message is indicated as urgent, it may be processed by the current node according to a message priority protocol.

[0069] These parameters, namely the number of hops NbHop, the message age AgeMsg and / or the message urgency parameter, can be initialized by the message sender, or by the first node sending the message in the network.

[0070] In addition, the node can include a table of processed messages TabMsg. Thus, when a message is transmitted to the current node, if this message is identified as being part of the processed messages, the message will be ignored by the node, otherwise it will be processed by the current node. This preliminary step prevents a node from processing the same message multiple times.

[0071] The processed message table may preferably have a fixed size, and implement a FIFO (First In First Out) operation. Alternatively, the processed message table may be cleaned based on the age of the processed messages, where the message age is an accessible data item. Other operations of the processed message table may be considered.

[0072] In case the current node decides to forward the message, before retransmitting the message, the geographic location LocSender of the sending node is updated to the geographic location LocNode of the current node.

[0073] The network is preferably a mesh network, also known as a mesh network. "mesh" in English, in particular a collaborative network ("crowd network") or resilient network ("disaster network"). In the mesh network, the nodes are connected peer to peer without a central hierarchy, each of the nodes being able to receive, send and retransmit a message. In such a network, a message is thus transmitted by a source to arrive at a destination by being able to pass through intermediate nodes which receive and retransmit the message. In other words, the message can be transmitted from the source to the destination via nodes which do not have a direct communication link between them. The implementation of a mesh network makes it possible to increase the robustness of the network by avoiding having hotspots, which in the event of a failure, can hinder the operation of the network. Indeed, in a mesh network, if a node fails, the message can be transmitted via an alternative route.

[0074] Within the network, messages can be transmitted in a flooding mode, commonly referred to as "flooding" in English. In this transmission mode, A message is sent by a sending node without specifying the receiving node. Thus, any listening node can receive the message and must process it. The message can then be retransmitted in a similar manner. Message retransmission stops when the receiving node matches the specified destination node(s), or if other constraint parameters are met, for example, if a maximum message hop count is reached.

[0075] Alternatively, messages can be transmitted using a point-to-point mode, commonly referred to as peer-to-peer. In this mode of message transmission, a message is sent by a sending node specifying the addresses of the receiving node(s). Thus, any listening node can ignore the message if it is not part of the receiving node(s). In point-to-point mode, routes are predefined. The network must then provide seamless connections or alternatively, alternative routes can be provided.

[0076] In the following description, a node will be described in more detail, the technical characteristics developed being applicable to all nodes in the network. The node is typically a small, low-energy device.

[0077] [Fig.6] illustrates one of the nodes of the network. The node comprises a processor PROC and a memory MEM storing at least instructions of a computer program and accessible by the processor to implement the method as previously described when the processor PROC executes the instructions of the program. The memory MEM of the node notably comprises a random access memory and a storage memory.

[0078] The node's MEM memory stores the geographic location LocNode of the respective node and the routing angle AngleRouting or the function for determining the routing angle.

[0079] Where appropriate, the node's memory may store the neighbor table ListNdDist, the processed message table, and / or additional constraint parameters such as the maximum hop count NbHopMax, the message lifetime AgeLimit, or a parameter relating to the urgency of the message. The processed message table may be stored in non-volatile memory of the node, such as flash memory or a hard disk, depending on the network's needs.

[0080] Furthermore, the node comprises in particular a first communication interface C0M1 controlled by the processor PROC, in order to receive and transmit messages to other nodes of the network, in particular with the neighboring nodes of the node considered. The first communication interface COM is controlled by the processor.

[0081] The node may include a second communication interface COM2 controlled by the processor PROC, in order to receive and transmit routing data to other nodes in the network.

[0082] The first and second communication interfaces may in particular be the same.

[0083] Each of the first and second communication interfaces COM1 and COM2 may preferably consist of an RF radio frequency communication interface allowing the nodes to communicate with each other without going through a central system. By way of non-limiting example, the communication interface may comply with 2G, 3G, 4G or 5G standards according to 3GPP. Low-power communication interfaces may in particular be preferred, such as Lora, BLE or SigFox. Other D2D (“Device to Device”) type communication interfaces in 6G may also be considered in the future, provided that constraints in terms of cost and energy consumption allow it.

[0084] Additionally, at least some nodes may include external sensors that can generate messages to be transmitted over the network (environmental sensors, counters).

[0085] Each node may further include power supply means, for example a battery, a wired power supply, solar panels, or a combination of these power supply means.

Claims

Claims

1. Routing method for routing a message (3) via nodes (2) of a network (1), in which the message (3) comprises geographic destination data (LocDest), and the method, implemented by a current node of the network (1), comprises: - upon receipt (El) of a message comprising said geographic destination data, and originating from a transmitting node, - decide (E4) to transmit or not to transmit the message depending on a desired direction of transmission of the message determined according to the geographic destination data (LocDest) and a direction taken by the message between the sending node and the current node.

2. A method according to claim 1, comprising: - determine (E2) the desired direction of transmission of the message comprising the determination of a destination vector (VecDest) collinear with the direction connecting a geographical location (LocNode) of the current node and the geographical destination (LocDest), - determine (E3) the direction taken by the message including obtaining an arrival vector (VecArr) collinear with the direction connecting the geographical location (LocNode) of the current node and the geographical location (LocSender) of the sending node.

3. Method according to the preceding claim, in which deciding (E4) to transmit or not to transmit the message comprises comparing (E42) a retransmission angle (AngleVec), determined (E41) as a function of the arrival vector (VecArr) and the destination vector (VecDest), with a routing angle (AngleRouting).

4. The method of claim 3, wherein the routing angle (AngleRouting) is a constant data.

5. Method according to claim 3, in which the routing angle (AngleRouting) is data determinable as a function of at least one routing parameter carried by the message.

6. Method according to one of the preceding claims, in which the message carries a geographic location (LocSender) of the sending node.

7. Method according to one of the preceding claims, in which the message carries an address of the sending node and the current node comprises a table, called the neighbor table (ListNdDist), listing the neighboring nodes to the current node, each neighboring node being identified by an address (NdDist) and each neighboring node being associated with data relating to a geographical location of the respective neighboring node, the arrival vector (VecArr) being obtained according to the neighbor table (ListNdDist) when the address of the sending node is present in the neighbor table (ListNdDist).

8. Method according to one of the preceding claims, in which the transmitting node is the last node having transmitted the message to the current node.

9. Method according to one of the preceding claims, in which the message comprises a number of hops (NbHop) and the decision (E4) to transmit or not to transmit the message is further carried out as a function of the number of hops (NbHop).

10. Method according to the preceding claim, in which the method is implemented as soon as the number of hops (NbHop) of the message reaches a predetermined number of hops since the first transmission of the message.

11. Method according to one of the preceding claims, in which the message comprises an age (AgeMsg) and the decision (E4) to transmit or not to transmit the message is made according to the age of the message (AgeMsg).

12. Node (2) of a network (1) for the method according to any one of the preceding claims.

13. Computer program comprising instructions for implementing the method according to one of claims 1 to 11 when this program is executed by a processor (PROC).

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