METHOD AND DEVICE FOR SELECTING A NODE IN A LOCAL NETWORK

Abstract

The present invention relates to a method and a device for reconfiguring a first interconnection of a first node with a second node of a routing subnetwork in a local area network comprising a plurality of nodes, the first and second nodes being interconnected by a radio link in a first frequency band. According to the invention, a so-called controller node: - selects (E320) a third node of the local area network, the third node being different from the first and second nodes, - establishes (E321) a second interconnection between the first and third nodes by a radio link in a second frequency band different from the first frequency band, - deletes (S423) the first interconnection when the second interconnection is established. Fig. 3c

Description

Title of the invention: METHOD and Device for SELECTING A node in a local network Technical field

[0001] The present invention relates to a method and a device for reconfiguring a local network comprising nodes allowing an extension of wireless communication coverage in order to increase the range of the local network by coordinating several access points integrated into the nodes. STATE OF PRIOR ART

[0002] In local area networks (LANs), wireless communication coverage extension systems can be used to increase the range of these local area networks (LANs) by coordinating several distributed access points (APs). These different access points (APs) are integrated into communication nodes, simply called nodes hereinafter, interconnected by means of a routing or backhaul subnetwork and all provide the same wireless local area network (WLAN).

[0003] The nodes of the routing subnetwork are connected to each other using a tree-like mesh structure, whereby a node can act as a relay between two other nodes of the routing subnetwork. The nodes of the routing subnetwork are thus interconnected using wired links, for example Ethernet, or wireless links. The nodes of the routing subnetwork are connected to each other by a network also called a “BackHaul Network” which can be either wired, wireless, or a combination of both.

[0004] Each node of the routing subnetwork possibly emits at least one wireless network called a "FrontHaul Network" or front network to which the user's stations connect. This front network, if it uses Wi-Fi / IEEE 802.11 technology, is the equivalent of what is called BSS (Basic Service Set).

[0005] At least one of the nodes in the routing subnetwork is connected to a residential gateway that provides access to the Internet. The residential gateway may also be part of the routing subnetwork.

[0006] In the context of the nodes of the routing subnetwork coupled or not to a residential gateway, the choice of the frequency band used for the routing subnetwork was formerly limited to the 2.4 GHz frequency band (limited in terms of flow rate, very congested) and the 5 GHz band allowing higher flow rates. In fact, the 5 GHz band was often preferred for the choice of the sub- routing network. This routing subnet functionality is provided by a dedicated or non-dedicated radio interface.

[0007] Each radio of a node of the routing subnetwork has a client part (station) which is associated with an access point of another node of the routing subnetwork. This access point can be dedicated to the functionality of the routing subnetwork or be the same as that dedicated to the front network.

[0008] Today, most solutions use only one band for the routing subnet. This choice obviously forces the channel to be the same for all radios of the equipment used for the routing subnet function.

[0009] The opening of the 6 GHz band to Wi-Fi technologies now makes it possible to have two frequency bands supporting high-speed transmissions (5 GHz and 6 GHz) and therefore candidates for the function of a routing subnetwork.

[0010] The tree-like topology introduces latency in data transmission and it is sometimes necessary to reconfigure the routing subnetwork. During the reconfiguration of the routing network, WiFi connections between the nodes of the routing subnetwork are deleted and others are added. During the reconfiguration, the user stations of the front-end network that are connected to the nodes involved in the reconfiguration of the routing subnetwork may temporarily experience loss of connections.

[0011] The present proposed invention makes it possible to ensure that the stations which are connected to the nodes involved in the reconfiguration of the routing subnetwork do not suffer any loss of connection. Statement of the invention

[0012] To this end, according to a first aspect, an embodiment proposes a method for reconfiguring a first interconnection of a first node with a second node of a routing subnetwork in a local network comprising a plurality of nodes allowing an extension of wireless communication coverage in order to increase the range of the local network by coordinating several access points integrated into the nodes, the first and second nodes being interconnected by a radio link in a first frequency band, characterized in that the method comprises the steps, executed by a so-called controller node, of:

[0013] - selection of a third node of the local network, the third node being different from the first and second nodes,

[0014] - establishing a second interconnection between the first and third nodes by a radio link in a second frequency band different from the first frequency band,

[0015] - deletion of the first interconnection when the second interconnection is established.

[0016] An embodiment also relates to a device for reconfiguring a first interconnection of a first node with a second node of a routing subnetwork in a local network comprising a plurality of nodes allowing an extension of wireless communication coverage in order to increase the range of the local network by coordinating several access points integrated into the nodes, the first and second nodes being interconnected by a radio link in a first frequency band, characterized in that the device is included in a so-called controller node, and comprises:

[0017] - means for selecting a third node of the local network, the third node being different from the first and second nodes,

[0018] - means for establishing a second interconnection between the first and the third nodes by a radio link in a second frequency band different from the first frequency band,

[0019] - means for removing the first interconnection when the second interconnection is established.

[0020] According to a particular embodiment, the nodes of the routing subnetwork are connected to each other by means of a tree-shaped mesh structure, the first node serving as a relay between a higher hierarchical level node in the tree and a lower hierarchical level node in the tree and the third node is not a lower hierarchical level node for which the first node serves as a relay.

[0021] According to a particular embodiment, the nodes of the routing subnetwork are connected to each other using a mesh structure and the method further comprises the steps of:

[0022] - checking whether establishing the second interconnection creates two paths for the transfer of data between two nodes of the mesh network, and if so

[0023] - interruption of data transfer between the two nodes of the mesh network on a of both paths.

[0024] According to a particular embodiment, the method further comprises the steps of:

[0025] - selection of a fourth node of the local network, the fourth node being different from the second knot,

[0026] - establishment, when the first interconnection is deleted, of a third interconnection between the first and fourth nodes by a radio link in the first frequency band.

[0027] According to a particular embodiment, the method further comprises the step of deleting the second interconnection when the third interconnection is established.

[0028] According to a particular embodiment, the nodes of the routing subnetwork are connected to each other by means of a tree-shaped mesh structure, the third node serving as a relay between at least one higher hierarchical level node in the tree and at least one lower hierarchical level node in the tree and the fourth node is not a lower hierarchical level node for which the third node serves as a relay.

[0029] According to a particular embodiment, the nodes of the routing subnetwork are connected to each other using a mesh structure and the method further comprises the steps of:

[0030] - checking whether establishing the third interconnection creates two paths for data transfer between two nodes of the mesh network, and if so

[0031] - interruption of data transfer between the two nodes of the mesh network on a of both paths.

[0032] A particular embodiment also relates to a computer program product. It comprises instructions for implementing, by a device, the method according to one of the preceding embodiments, when said program is executed by a processor of the device.

[0033] A particular embodiment also relates to a storage medium. It stores a computer program comprising instructions for implementing, by a node device, the method according to one of the preceding embodiments, when said program is executed by a processor of the node device. Brief description of the drawings

[0034] The above-mentioned features of the invention, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0035] [Fig-1] schematically illustrates an example of a local network in a mode of realization ;

[0036] [Fig.2] schematically illustrates the architecture of a node according to one embodiment;

[0037] [Fig.3a] illustrates an example of a method carried out according to a first embodiment;

[0038] [Fig.3b] illustrates an example of a method carried out according to a second embodiment;

[0039] [Fig.3c] illustrates an example of a method carried out according to a third mode of realization ;

[0040] [Fig.4a], [Fig.4b], [Fig.4c] and [Fig.4d] illustrate an example of reconfiguration of a local network comprising nodes allowing an extension of wireless communication coverage according to the first embodiment;

[0041] [Fig.5a], [Fig.5b], [Fig.5c] and [Fig.5d] illustrate an example of reconfiguration of a local network comprising nodes allowing an extension of wireless communication coverage according to the second embodiment;

[0042] [Fig.6a] and [Fig.6b] illustrate an example of reconfiguration of a local network comprising nodes enabling wireless communication coverage extension according to the third embodiment;

[0043] [Fig.7] schematically illustrates different elements of a node according to a mode of realization.

[0044] DETAILED DESCRIPTION OF EMBODIMENTS

[0045] [Fig.l] illustrates an example of a local area network in one embodiment.

[0046] The mesh local area network is built around a routing subnetwork comprising a set of interconnected nodes 100a to 100g.

[0047] The node 100a is for example a residential gateway which provides access to a wide area network, such as for example the Internet network.

[0048] The nodes 100b to 100g are wireless communication coverage extension systems that are used to increase the range of the local network by coordinating several distributed access points AP (“Access Points”). These different access points AP are integrated into the nodes that are interconnected using a routing or backhaul subnetwork and all provide a single WLAN wireless local area network. In one example, some or all of the nodes 100b to 100g are wireless coverage “extenders”.

[0049] Node 100a may be included in the routing subnetwork.

[0050] The nodes 100a to 100g of the routing subnetwork are connected to each other by means of a tree-shaped mesh structure, whereby a node can serve as a relay between two other nodes of the routing subnetwork. The nodes of the routing subnetwork are, for example, interconnected by means of wireless links.

[0051] Each node of the routing subnetwork emits at least one wireless network called a "FrontHaul Network" or front network to which the user's stations connect. This front network, if it uses Wi-Fi / IEEE 802.11 technology, is the equivalent of what is called BSS (Basic Service Set).

[0052] In the example of [Fig.l], node 100a is connected to nodes 100b and 100c, node 100b is interconnected to node lOOd, node lOOd is connected to node 100g, node 100c is connected to node lOOf, node lOOf is connected to node 100e.

[0053] At least a portion of the nodes 100a to 100g of the routing subnetwork comprises a plurality of radio interfaces.

[0054] The elements of a node are described in more detail with reference to [Fig.7].

[0055] [Fig.7] schematically illustrates different elements of a node 100 according to one embodiment.

[0056] At least a portion of the nodes 100a to 100g of the routing subnetwork comprises:

[0057] - a RAI radio interface operating on a first frequency band by example the 5GHz frequency band,

[0058] - an RA2 radio interface operating on a second frequency band by example the 6 GHz frequency band,

[0059] The first RAI radio interface comprises:

[0060] - a bSTAl.l client interface of the routing subnet,

[0061] - an AP 1.2 access point interface of the routing subnet, the point interface AP1.2 access being dedicated to the association of client interface of other nodes of the routing network (Backhaul Network),

[0062] - optionally an AP1.1 access point interface corresponding to an interface user local network access point, this interface being dedicated to the association of stations or terminals (Front-end network),

[0063] - a radio channel denoted A for transmission and reception in the frequency band of RAI radio.

[0064] The second radio interface RA2 comprises:

[0065] - a bSTA2.1 client interface of the routing subnet,

[0066] - an AP2.2 access point interface of the routing subnet, the access point interface AP2.2 access being dedicated to the association of client interface of other nodes of the routing network (Backhaul Network),

[0067] - optionally an AP2.1 access point interface corresponding to an interface user local network access point, this interface being dedicated to the association of stations or terminals (Front-end network),

[0068] - a radio channel noted B for transmission and reception in the frequency band of RA2 radio.

[0069] It should be noted here that only two radio channels are represented for the sake of simplification. Of course, the nodes can have a greater number of radio channels.

[0070] The term “node” is understood hereinafter to mean equipment offering connectivity capabilities and constituting the local mesh network.

[0071] The term "station" is hereinafter understood to mean fixed or mobile equipment using the resources of the mesh local network via the intermediary of the nodes of said local network. A station is, for example, a wireless mobile terminal, a wireless speaker.

[0072] In different examples, the equipment, nodes or stations, are each respectively compatible with one or more standards of the IEEE 802.11 family of standards.

[0073] A radio can host several access point interfaces, each AP access point interface having its own connection parameters (eg an access point interface for a private network, a public network, a video network, etc.).

[0074] Each new node or station that is searching for an access point to associate with may, before association, choose the optimal access point in the network topology. Each new node or station may also decide whether the propagation conditions (for example based on a received signal strength indicator (RSSI)) between the various possible access points are equivalent, and favor a radio interface not used for the routing subnetwork.

[0075] The stations are for example smart phones (“smartphone” in English) or a tablet, a computer, a television, a NAS (“Network Attached Storage” in English) network storage unit.

[0076] [Fig.2] schematically illustrates the architecture of a node according to one embodiment.

[0077] According to the example of hardware architecture represented in [Fig.2], at least the nodes 100b, 100d and 100e, comprise, connected by a communication bus 200: a processor or CPU (“Central Processing Unit” in English) 201; a RAM (“Random Access Memory” in English) 202; a ROM (“Read Only Memory” in English) 203; a storage unit such as a hard disk (or a storage media reader, such as an SD (“Secure Digital” in English) card reader) 204; at least one communication interface 205 allowing the node to communicate with the equipment of the local network.

[0078] The processor 201 is capable of executing instructions loaded into the RAM 202 from the ROM 203, from an external memory (not shown), from a storage medium (such as an SD card), or from a communication network. When the node is powered on, the processor 201 is capable of reading instructions from the RAM 202 and executing them. These instructions form a computer program causing the processor 201 to implement all or part of the method described in relation to Figs. 3.

[0079] The method described below in relation to Figs. 3 may be implemented in software form by executing a set of instructions by a programmable machine, for example a DSP (Digital Signal Processor) or a microcontroller, or be implemented in hardware form by a machine or a dedicated component, for example an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit). In general, the node comprises electronic circuitry configured to implement the methods described in relation to Figs. 3.

[0080] [Fig.3a] illustrates an example of a method carried out according to a first embodiment.

[0081] This algorithm is executed by a node called the routing subnetwork controller.

[0082] The present algorithm is for example executed when a reconfiguration of a local network must be carried out.

[0083] According to the first embodiment, the interconnection between a first node 100e and a second node 100f must be replaced by an interconnection between the first node 100e with a fourth node 100b by temporarily using a third node 100d.

[0084] The controller is for example included in node 100a.

[0085] In step E300, the controller selects a temporary node, for example node lOOd.

[0086] The nodes of the routing subnetwork are connected to each other through a tree-like mesh structure, the first node serves as a relay between higher hierarchical level nodes in the tree and lower hierarchical level nodes in the tree, and the third and fourth nodes are different from the lower hierarchical level nodes for which the first node serves as a relay.

[0087] In step E301, the controller commands the establishment of a second interconnection between the first and third nodes by a radio link in a second frequency band different from the first frequency band. An example of the establishment of a second interconnection between the first and third nodes is given in [Fig.4a].

[0088] In step E302, the controller checks whether the establishment of the second interconnection creates two paths for the transfer of data between two nodes of the mesh network forming a loop and, if so, commands the interruption at the logical level of the transfer of data between the two nodes of the mesh network on one of the two paths. It should be noted here that neither of the two physical paths is deleted.

[0089] In step E303, the controller commands the deletion of the first interconnection when the second interconnection is established. An example of the removal of the first interconnection between the first and second nodes is given in [Fig.4b].

[0090] In step E304, the controller commands the establishment, when the first interconnection is deleted, of a third interconnection between the first and the fourth nodes by a radio link in the first frequency band. An example of the establishment of a second interconnection between the first and the third nodes is given in [Fig.4c].

[0091] In step E305, the controller checks whether the establishment of the second interconnection creates two paths for the transfer of data between two nodes of the mesh network, and if so, orders the interruption of the transfer of data between the two nodes of the mesh network on one of the two paths.

[0092] In step E306, the controller commands the deletion of the second interconnection when the third interconnection is established. An example of the establishment of a second interconnection between the first and the third nodes is given in [Fig.4c].

[0093] [Fig.3b] illustrates an example of a method carried out according to a second embodiment.

[0094] This algorithm is executed by a node called the routing subnetwork controller.

[0095] The present algorithm is for example executed when a reconfiguration of a local network must be carried out.

[0096] According to the second embodiment, the interconnection between the first node 100e and the second node 100f is to be replaced by an interconnection between the first node 100e with the fourth node 100b by temporarily using another radio channel of the fourth node. The fourth node is hereinafter called the third node 100b.

[0097] The controller is for example included in node 100a.

[0098] In step E310, the controller selects a temporary node, for example the third node 100b.

[0099] The nodes of the routing subnetwork are connected to each other through a tree-like mesh structure, the first node serves as a relay between higher hierarchical level nodes in the tree and lower hierarchical level nodes in the tree, and the third and fourth nodes are different from the lower hierarchical level nodes for which the first node serves as a relay.

[0100] In a tree-shaped mesh network, a group or branch of nodes can be defined when these nodes are connected by a wireless backhaul, and one of the nodes in the group is connected to another group via an Ethernet backhaul network. Within a single group of nodes, the wireless backhaul network uses the same channel for all interconnections between the nodes in the group.

[0101] In step E311, the controller commands the establishment of a second interconnection between the first and third nodes by a radio link in a second frequency band different from the first frequency band. An example of the establishment of a second interconnection between the first and third nodes is given in [Fig.5a].

[0102] In step E312, the controller checks whether the establishment of the second interconnection creates two paths for the transfer of data between two nodes of the mesh network forming a loop and, if so, commands the interruption at the logical level of the transfer of data between the two nodes of the mesh network on one of the two paths. It should be noted here that neither of the two physical paths is deleted.

[0103] In step E313, the controller commands the deletion of the first interconnection when the second interconnection is established. An example of the deletion of the first interconnection between the first and the second nodes is given in [Fig.5b].

[0104] In step E314, the controller commands the establishment, when the first interconnection is deleted, of a third interconnection between the first and the fourth nodes by a radio link in the first frequency band. An example of the establishment of a second interconnection between the first and the third nodes is given in [Fig.5c].

[0105] In step E315, the controller checks whether the establishment of the second interconnection creates two paths for the transfer of data between two nodes of the mesh network, and if so, orders the interruption of the transfer of data between the two nodes of the mesh network on one of the two paths.

[0106] In step E316, the controller commands the deletion of the second interconnection when the third interconnection is established. An example of the establishment of a second interconnection between the first and the third nodes is given in [Fig.5c].

[0107] Alternatively, step E316 is not executed.

[0108] It should be noted that alternatively, the interconnection between the first node 100e with the fourth node 100b is carried out by temporarily using another radio channel of the first node. The first node is then called the third node 100b.

[0109] [Fig.3c] illustrates an example of a method carried out according to a third embodiment.

[0110] This algorithm is executed by a node called the routing subnetwork controller.

[0111] The present algorithm is for example executed when a reconfiguration of a local network must be carried out.

[0112] According to the third embodiment, the interconnection between the first node 100e and the second node 100f must be replaced by an interconnection between the first node 100e with the fourth node 100b.

[0113] The controller is for example included in node 100a.

[0114] In step E320, the controller selects a temporary node, for example the third node 100b.

[0115] The nodes of the routing subnetwork are connected to each other through a tree-like mesh structure, where the first node serves as a relay between higher hierarchical level nodes in the tree and lower hierarchical level nodes in the tree and the third node is different from the lower hierarchical level nodes for which the first node serves as a relay.

[0116] In step E321, the controller commands the establishment of a second interconnection between the first and third nodes by a radio link in a second frequency band different from the first frequency band. An example of the establishment of a second interconnection between the first and third nodes is given in [Fig.6a].

[0117] In step E322, the controller checks whether the establishment of the second interconnection creates two paths for the transfer of data between two nodes of the mesh network forming a loop and, if so, commands the interruption at the logical level of the transfer of data between the two nodes of the mesh network on one of the two paths. It should be noted here that neither of the two physical paths is deleted.

[0118] In step E323, the controller commands the deletion of the first interconnection when the second interconnection is established. An example of the deletion of the first interconnection between the first and second nodes is given in [Fig.6b].

[0119] In other embodiments, the controller of the routing subnetwork is included in one of the nodes of the tree-like mesh structure. For example, when the interconnection between node 100e and node 100f is reconfigured into an interconnection between node 100e and node 100b, the controller may be included in said node 100b or node 100c.

[0120] In other embodiments, the routing subnetwork controller is a function provided by equipment external to the mesh structure. For example, this external equipment cooperates with the node 100a connected to the extended network in order to allow the interconnections between the nodes to be reconfigured.

Claims

Claims

1. Method for reconfiguring a first interconnection of a first node with a second node of a routing subnetwork in a local area network comprising a plurality of nodes allowing an extension of wireless communication coverage in order to increase the range of the local area network by coordinating several access points integrated into the nodes, the first and second nodes being interconnected by a radio link in a first frequency band, characterized in that the method comprises the steps, executed by a so-called controller node, of: - selecting (E320) a third node of the local area network, the third node being different from the first and second nodes, the nodes of the routing subnetwork are connected to each other using a tree-shaped mesh structure,the first node serving as a relay between at least one higher hierarchical level node in the tree and at least one lower hierarchical level node in the tree and the third node is not a lower hierarchical level node for which the first node serves as a relay, - establishment (E321) of a second interconnection between the first and the third nodes by a radio link in a second frequency band different from the first frequency band, - deletion (E323) of the first interconnection when the second interconnection is established.,

2. Method according to claim 1, characterized in that the nodes of the routing subnetwork are connected to each other by means of the tree-shaped mesh structure and the method further comprises the steps of: - checking whether the establishment of the second interconnection creates two paths for the transfer of data between two nodes of the mesh network, and if so - interrupting the transfer of data between the two nodes of the mesh network on one of the two paths.

3. Method according to claim 1, characterized in that the method further comprises the steps of: - selecting a fourth node of the local network, the fourth node being different from the second node, - establishment, when the first interconnection is removed, of a third interconnection between the first and fourth nodes by a radio link in the first frequency band.

4. A method according to claim 3, characterized in that the method further comprises the step of removing the second interconnection when the third interconnection is established.

5. A method according to claim 4 or 5, characterized in that the nodes of the routing subnetwork are connected to each other by means of a tree-shaped mesh structure, the third node serving as a relay between at least one higher hierarchical level node in the tree and at least one lower hierarchical level node in the tree and the fourth node is not a lower hierarchical level node for which the third node serves as a relay.

6. A method according to any one of claims 1 to 5, characterized in that the nodes of the routing subnetwork are connected to each other by means of the tree-shaped mesh structure and the method further comprises the steps of: - checking whether the establishment of the third interconnection creates two paths for the transfer of data between two nodes of the mesh network, and if so - interrupting the transfer of data between the two nodes of the mesh network on one of the two paths.

7. Device for reconfiguring a first interconnection of a first node with a second node of a routing subnetwork in a local area network comprising a plurality of nodes allowing an extension of wireless communication coverage in order to increase the range of the local area network by coordinating several access points integrated into the nodes, the first and second nodes being interconnected by a radio link in a first frequency band, characterized in that the device is included in a so-called controller node, and comprises: - means for selecting a third node of the local area network, the third node being different from the first and second nodes, the nodes of the routing subnetwork are connected to each other by means of a tree-shaped mesh structure, the first node serving as a relay between at least one node of a higher hierarchical level in the tree and at least one node of a higher hierarchical level in the tree, the third node being different from the first and second nodes, the nodes of the routing subnetwork are connected to each other by means of a tree-shaped mesh structure, the first node serving as a relay between at least one node of a higher hierarchical level in the tree and at least one node of a higher hierarchical level in the tree, the third node being different from the first and second nodes, the nodes of the routing subnetwork being ... lower hierarchical level in the tree and the third node is not a lower hierarchical level node for which the first node serves as a relay, - means for establishing a second interconnection between the first and third nodes by a radio link in a second frequency band different from the first frequency band, - means for deleting the first interconnection when the second interconnection is established.

8. A computer program product characterized in that it comprises instructions for implementing, by equipment, the method according to any one of claims 1 to 6, when said program is executed by a processor of the equipment.

9. A storage medium characterized in that it stores a computer program comprising instructions for implementing, by equipment, the method according to any one of claims 1 to 6, when said program is executed by a processor of the equipment.

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