JP2012065116A - Repeater, mpp, data communication network, inter-network communication method, program, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible for nodes being a component of each different ad-hoc radio LAN mesh network to perform data communication among them according to an on-demand type routing protocol.SOLUTION: A router 21 of an Ethernet (R) 20 learns an address of each node and a radio LAN mesh network including the node in advance. When communication is performed between different radio LAN mesh networks 100and 100like data communication from a transmission source node (1) to a destination node (4), the router 21 relays data communication by: constructing a route of each radio LAN mesh network by relaying a route request and a route response as if each of the transmission source node and the destination node exists in the same radio LAN mesh network, and performing conversion so that the address of the transmission source node is correctly communicated to the network including the destination node in receiving/transmitting data by the Ethernet (R) 20.

Description

  The present invention relates to an ad hoc wireless LAN mesh network, and more specifically, a relay that enables data communication between nodes as constituent elements of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol, MPP ( Mesh Portal Point), a data communication network including these relays and MPPs as elements, an inter-network communication method for performing the data communication, and a program.

In recent years, with the development of wireless technology, there are many network configuration examples in which a network that has been conventionally connected by wire has been changed to a wireless connection form. For example, LAN (Local Area Network) has been mainly connected to wired Ethernet (registered trademark) represented by IEEE (Institute of Electrical and Electronic Engineers) 802.3, but in recent years is represented by IEEE 802.11 system. A wireless LAN connection is used in many information communication devices.
However, in the conventional wireless LAN communication, since a network is constructed by comprehensive control by an AP (access point), there is a problem in laying a wired network for AP connection and flexibility in network layout. The wired network is used to connect APs and expand the network.

In order to solve these problems, an ad hoc wireless LAN mesh network has been attracting attention as a next-generation wireless communication technology. In this wireless LAN mesh network, overall communication control by the AP is not performed, and the network is formed by a method of determining a communication path for transferring traffic (data) by directly linking each communication node such as a mobile terminal.
A routing protocol for determining a communication path in an ad hoc wireless LAN mesh network is being standardized by IETF (Internet Engineering Task Force) MANET (Mobile Ad-hoc Network), IEEE 802.11s, and the like.

A wireless LAN mesh network includes four types of devices as components. With reference to one configuration example of the wireless LAN mesh network shown in FIG. 8, the components of this network will be described below.
The MP (Mesh Point) 11 implements only the function of the wireless LAN mesh network and mainly performs hopping (traffic transfer) to neighboring devices. A MAP (Mesh Access Point) 12 implements a wireless LAN access point function in addition to the MP11 function, and serves as an access point for the STA 17 described later. MPP (Mesh Portal Point) 13 implements a gateway function for connecting to an external network such as Ethernet (registered trademark) 20 in addition to the function of MP11. The STA (Station) 17 is a wireless LAN terminal that does not implement a wireless LAN mesh network function.

Mesh network routing protocols can be broadly divided into an on-demand type and a pro-active type.
In the on-demand type routing protocol, when data is transmitted, communication nodes transmit and receive a route request frame / route response frame, and then a route is constructed to perform data communication. Typical examples include RM-AODV (Radio Metric-AODV) improved from AODV (Adhoc On Demand Distance Vector).
In the proactive routing protocol, terminals that can be routed between communication nodes are confirmed at certain intervals, and a route is always constructed.
In IEEE802.11s of ad hoc wireless LAN mesh network, HWMP (Hybrid Wireless Mesh Protocol) has been proposed in which a function for constructing a tree structure is added to the RM-AODV protocol. It is attracting attention as an on-demand routing protocol that does not build a network.

A wireless LAN mesh network has a feature that data can be transferred over a wide range by linking and transferring highly mobile communication nodes such as mobile terminals.
However, when communication is performed using an on-demand routing protocol on an ad hoc wireless LAN mesh network, there is only a route construction when performing communication. Therefore, when a highly mobile node is the destination, the node It cannot be confirmed in advance that it exists within the network range. In ad hoc wireless LAN mesh network communication, if the number of transit nodes (hops) in route construction increases, the probability of data frame corruption due to packet collision increases, so we want to avoid an increase in the number of hops. Considering the possibility of an increase in the number of hops due to movement, it is difficult to perform a wide range of ad hoc wireless LAN mesh network communication. For this reason, it is inevitable that a scene in which the ad hoc wireless LAN mesh network communication cannot be used as the user desires will occur.
In addition, for example, communication nodes exist within the mesh network range, and communication was performed using an on-demand routing protocol. However, since the destination node has moved to another location, data can be transmitted and received. There may be cases where it disappears. In addition, two wireless communication nodes are communicating in an office room of the same ad hoc wireless LAN mesh network range, but other rooms and conference rooms whose destination node is temporarily in a different wireless LAN mesh network range When moving to another building, the source node cannot construct a route and cannot perform this communication.

IEEE802.11s, which defines a wireless LAN mesh network, proposes a function in which an MPP device (hereinafter simply referred to as “MPP”) operates as a bridge in an IEEE802 wired LAN network. This MPP bridge connects to another wireless LAN mesh network via a wired network such as Ethernet (registered trademark) after that even if the communication node moves out of the range of the wireless LAN mesh network and cannot transfer the data frame. Then, a route can be secured from the transmission source node to the destination node by the MPP broadcast, and the data frame can be transferred.
Further, as a prior art that uses a different network in the middle of a communication path, it has been proposed to perform ad hoc wireless network communication by connecting nodes constituting a wireless LAN mesh network via the Internet. Japanese Patent No. 4406377).

However, in a conventional technology based on IEEE802.11s that connects a source node and a destination node belonging to different wireless LAN mesh networks via a wired network such as Ethernet (registered trademark), the MPP transmits a frame. At this time, the frame is converted from the mesh network frame to the wired network frame. At that time, the source address is converted from the address of the source node to the address of the MPP, so that the destination node receiving the frame is the data frame from the source node. Then, even if an attempt is made to exchange data necessary for the transmission source node, a data frame cannot be returned. Moreover, there is a problem that the network performance is deteriorated because it is transferred by broadcast.
Therefore, when one wireless communication node moves out of the wireless LAN mesh network range, data frames cannot be transmitted / received by the ad hoc wireless LAN mesh network until the communicating wireless communication nodes enter the same mesh network range again. There was a problem.

In Patent Document 1, when hopping is performed in a wireless LAN mesh network, a wire is routed on the way, but a route using an on-demand routing protocol cannot be established between different wireless LAN mesh networks, and data communication is performed. Therefore, Patent Document 1 cannot solve the above-described problem of the conventional technology that occurs between wireless LAN mesh networks.
The present invention has been made in view of the above-described problems that occur in the prior art of wireless LAN mesh networks, and its purpose is to perform data communication performed between nodes of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol. There is in making it possible.

The present invention is a relay device for relaying data communication performed between nodes of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol, and an address learning means for learning the address of a node in the network; The relay necessity / unnecessity confirmation means for confirming whether or not relaying is necessary depending on whether or not the destination node indicated in the received route request exists in the network to which the transmission source node belongs, and the relay necessity / unnecessity confirmation means requires relaying. First communication path determination means for determining a communication path between the transmission source node and the repeater in the network to which the transmission source node belongs, on the condition that the transmission destination node is confirmed, and on the condition of the confirmation, Second communication path determination means for determining a communication path between a relay station and a destination node in the network to which it belongs; A source address for converting an address of a source node instructed with respect to received data into an original address when data communication is relayed on the path determined by the first communication path determination unit and the second communication path determination unit Conversion means.
The present invention is a relay device for relaying data communication performed between nodes of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol, and an address learning means for learning the address of a node in the network; The relay necessity / unnecessity confirmation means for confirming whether or not relaying is necessary depending on whether or not the destination node indicated in the received route request exists in the network to which the transmission source node belongs, and the relay necessity / unnecessity confirmation means requires relaying. A communication path determining means for determining a series of communication paths between the source node and the destination node from the network to which the source node belongs to the network to which the destination node belongs, on the condition that the source node belongs, When data communication is relayed on the route determined by the communication route determination means And having a source address converting means for converting the address of the source node is instructed to receive data to the original address.
The present invention is an MPP (mesh portal point) of a constituent element of the network that relays communication performed between the constituent elements of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol. Address learning means for learning the address of the node; relay necessity confirmation means for confirming whether or not relaying is necessary depending on whether or not the destination node indicated in the received route request exists in the network to which the transmission source node belongs; and A communication path between the source node and the destination node from the network to which the source node belongs to the network to which the destination node belongs via the MPP is determined on the condition that the relay necessity confirmation means confirms that the relay is necessary. Communication path determining means To.
The present invention is an inter-network communication method that relays data communication performed between nodes of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol, and a source node designates and issues a destination node The address learning step of receiving the route request and learning the address of the node in the network, and whether or not the relay is necessary depending on whether or not the destination node indicated in the received route request exists in the network to which the transmission source node belongs. Determine the communication route between the source node and the relay in the network to which the source node belongs, on the condition that the relay necessity confirmation step to be confirmed and the relay necessity confirmation step confirm that the relay is necessary First communication path determination step and communication path determined by the first communication path determination step Then, a second communication path determination step for determining a communication path between the relay station in the network to which the destination node of the relay communication belongs and the destination node, and the first communication path determination step and the second communication path determination step. A transmission source address conversion step of converting the address of the transmission source node instructed with respect to the received data into the original address when relaying data communication through the route.
The present invention is an inter-network communication method that relays data communication performed between nodes of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol, and a source node designates and issues a destination node The address learning step of receiving the route request and learning the address of the node in the network, and whether or not the relay is necessary depending on whether or not the destination node indicated in the received route request exists in the network to which the transmission source node belongs. A relay source that reaches from the network to which the source node belongs to the network to which the destination node belongs via the relay station, on the condition that the relay necessity confirmation step to be confirmed and the relay necessity confirmation step confirm that relay is necessary Communication path determination that determines a series of communication paths between a node and a destination node And a source address conversion step of converting the address of the source node indicated for the received data into the original address when data communication is relayed on the path determined by the communication path determination step It is characterized by.

  According to the present invention, nodes in an ad hoc wireless LAN mesh network are not limited to nodes within the same mesh network range, and data frames can be transmitted / received to / from nodes in other ad hoc wireless LAN mesh networks.

It is a figure which shows the communication condition of the structure of the wireless LAN mesh network and route request frame which concern on embodiment of this invention. It is a figure which shows the communication path | route of the path | route response frame which a destination node transmits in response to the path | route request | requirement of FIG. It is a figure explaining the communication operation | movement by the connection structure of a different wireless LAN mesh network which concerns on Embodiment 1 of this invention, and the relay function of a router. FIG. 4 is a flowchart of route construction processing performed by a router of the network shown in FIG. 3. It is a figure explaining the communication operation | movement by the connection structure of a different wireless LAN mesh network which concerns on Embodiment 2 of this invention, and the relay function of a router. It is a figure explaining the communication operation | movement by the connection structure of the different wireless LAN mesh network which concerns on Embodiment 3 of this invention, and the relay function of MPP. It is a figure explaining the connection structure and communication operation | movement of the modification of the network of FIG. It is a figure which shows the network structural example for demonstrating the component of a wireless LAN mesh network.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The following embodiment of the ad hoc wireless LAN mesh network according to the present invention is for enabling data communication performed by nodes of respective constituent elements of the network configured as different wireless LAN mesh networks according to an on-demand routing protocol. It has a relay machine or a relay function, and these are used via the MPP of the network. That is, a relay device or a relay function for connecting different wireless LAN mesh networks constitutes a component unique to this embodiment that is not present in the prior art.

[Wireless LAN mesh network]
First, an example of a basic configuration of a wireless LAN mesh network (hereinafter, also simply referred to as “wireless LAN mesh network” or “mesh network”) targeted by the present embodiment will be shown and the operation thereof will be described.
FIG. 1 is a diagram illustrating an example of a basic configuration of a wireless LAN mesh network according to an embodiment of the present invention. In the figure, a flow of a route request frame for explaining a communication state at the time of route request described later is shown.
Each node (1) to (10) constituting the wireless LAN mesh network 100 shown in FIG. 1, that is, MP (Mesh Point) 11 ₄ , 11 ₅ , 11 ₆ , 11 ₇ , 11 ₉ , MAP (Mesh Access) Point) 12 ₃ , 12 ₁₀ , MPP (Mesh Portal Point) 13 ₈ , and STA (Station) 17 ₁ , 17 ₂ correspond to the elements described above with reference to FIG. Also, MPP (Mesh Portal Point) 13 8 are Ethernet is connected to the router 21 ₁ (R) 20, where, via the router 21 _1, PC (Personal computer) _{22 11} like nodes (11 ).

In Figure 1, each node in a wireless LAN mesh network 100 performs a wireless LAN mesh network communication on-demand routing protocol, Ethernet (registered trademark) through the router 21 ₁ communicate with 20 on the node (11) Yes.
As shown in FIG. 1, when the STA 17 ₁ of the node (1) communicates with the STA 17 _{2 of the} node (2) belonging to the same wireless LAN mesh network, the STA 17 of the node (1) is first used in the on-demand routing protocol. ₁ broadcast-routes a route request frame (RREQ) to other nodes.
MAP12 ₃ nodes (3) for receiving a route request frame to be the broadcast forwarding, since the route request frame received is not a frame addressed to it, in the (example shown in FIG. 1 for broadcast forwarding to another node, the node ( 4) to (6) are transferable nodes).

Among the nodes that receive the route request frame broadcast-transmitted by the node (3), the MP11 ₄ of the node (4) is similarly sent to the MAP 12 ₁₀ of the node (10), and the node (10) is the node of the node (2). STA17 transfers the path request frame to _2.
Node ₍₂₎ STA17 2 is the path request frame (hereinafter, referred to as "RREQ") received confirms that is a frame addressed to it, as a response operation to route request, the turn sender of the route request destination A route response frame (hereinafter referred to as “RREP”) is transmitted.
FIG. 2 is a diagram showing the flow of RREP for explaining the communication status at the time of this route response. As shown in FIG. 2, the node STA17 ₂ is (2) receives the RREQ is a frame addressed to it, RREQ path that is transferred (in FIG. 1 stream, see) the RREP in the opposite direction to the turn Is transferred by unicast transmission.
In FIG. 2, RREP is transferred in the order of node (2) → node (10) → node (4) → node (3) → node (1). When STA17 ₁ node (1) receives the RREP, RREP is STA17 ₂ links STA17 ₁ and nodes of the node (1) in a path which has been transferred (2), it becomes possible for the first time of the data frame transfer.

[Relay between different wireless LAN mesh networks]
The wireless LAN has been described with reference to FIGS. 1 and 2 in the mesh network may be by the relay functions of MPP13 ₈ and the router 21 _1, extend the connectable network. However, when the relay function of these elements in the prior art is used for connection between different wireless LAN mesh networks, as described in the above [Problems to be solved by the invention], the source address is the source. Since the address of the node is converted to the address of the MPP device, the destination node that receives the frame cannot recognize that it is a data frame from the source node, and then exchange data necessary for the source node. However, there arises a problem that the data frame cannot be returned.

Therefore, in this embodiment, a relay node or a relay function is provided so that a destination node that receives data from a transmission source node between different wireless LAN mesh networks can exchange data for returning data to the previous transmission source. To solve the above problem.
Hereinafter, <Embodiment 1> to <Embodiment 5> will be described as embodiments of a wireless LAN mesh network having the relay function of the present embodiment.
<Embodiment 1> and <Embodiment 2> are the same in that an Ethernet (registered trademark) router has the relay function. The difference between the two is that the operation modes of the route request and the route response are different.
<Embodiment 3> and <Embodiment 4> are the same in that the MPP configuring the wireless LAN mesh network has the relay function. The difference between the two is whether the configuration is configured by MPP common to different wireless LAN mesh networks or the configuration configured by MPP of different wireless LAN mesh networks.
<Embodiment 5> relates to management of addresses of nodes constituting each wireless LAN mesh network.

<Embodiment 1>
In this embodiment, an Ethernet (registered trademark) router has the relay function. In order for the router to have the relay function, it is necessary to learn the addresses of the nodes constituting each of the different wireless LAN mesh networks and manage the obtained addresses.
In a wireless LAN mesh network of FIG. 1, router 21 ₁ Ethernet 20 connected through MPP13 ₈ nodes (8), MPP13 Ethernet connection node (R) 20 (8) ₈ although it is possible to learn the address, for MPP13 of ₈ other than the wireless LAN mesh network node of the node (8), it is impossible to learn the address.
Therefore, when the STA 17 ₁ of the node (1) in the wireless LAN mesh network broadcasts the RREQ as in the route request frame transmission operation described above with reference to FIG. 1, the node (8) MPP13 when transferring ₈ to RREQ routers 21 ₁ to perform is to learn from the incoming RREQ. In the operation example of FIG. 1, the address of the node (1) indicated as the transmission source node in the RREQ of the received node (1) can be obtained.

By performing the above learning, the addresses of the nodes constituting each of the different wireless LAN mesh networks are obtained, and the relay function that works between the different wireless LAN mesh networks on the assumption that this management is performed is described with reference to FIGS. This will be described below.
FIG. 3 is a diagram for explaining a communication operation by a connection configuration of different wireless LAN mesh networks and a relay function of the router according to the first embodiment.
In the configuration shown in FIG. 3, different wireless LAN mesh wireless LAN mesh network is a network (1) 100 ₁ and a wireless LAN mesh network (2) 100 ₂ are connected by the router 21. Each of the connected wireless LAN mesh networks includes the same components as those of the wireless LAN mesh network 100 described above with reference to FIG.

In the network configuration of FIG. 3, when the STA 17 ₁ of the node (1) transfers a data frame to the STA 17 ₄ of the node (4), the node (1) first transmits the RREQ to the wireless LAN mesh network (1) 100 ₁ . Broadcast forward to. However, since the destination node (4) does not belong to the wireless LAN mesh network (1), the node (1) cannot directly transfer the RREQ to the node (4).
However, when the RREQ is sequentially transferred to the nodes belonging to the wireless LAN mesh network (1) 100 ₁ and received by the MPP 13 ₅ of the node (5), the router 21 of the Ethernet (registered trademark) 20 by the interface provided in the MPP 13 ₅ is used. Can be connected. Therefore, the router 21, the wireless LAN mesh network (1) 100 ₁ RREQ used as repeater for forwarding to another wireless LAN mesh network. That is, MPP13 ₅ nodes (5), when receiving the RREQ to the STA17 ₁ node (1) and the source node, transfers the RREQ to the router 21 of the Ethernet (registered trademark) 20. The router 21 that receives the RREQ can learn the address of the STA 17 ₁ of the node (1) by receiving the RREQ whose source address is the STA 17 ₁ of the node (1).

Here, a path construction process performed by the router 21 of the Ethernet (registered trademark) 20 when receiving the RREQ will be described with reference to a flowchart illustrated in FIG.
When the router 21 receives the RREQ from the MPP (in the example of FIG. 3, the MPP 13 ₅ of the node (5) or the MPP 13 _{6 of the} node (6)), the address of the source node and the destination node indicated in the RREQ Etc. are extracted (step S101).
Next, the address of the transmission source node extracted from the RREQ is learned, and information for identifying the wireless LAN mesh network to which the node belongs (in the operation example of FIG. 3, the node (1) that is the transmission source node belongs). Also identifies the wireless LAN mesh network (1) 100 ₁ ) (step S102).
Then, (in the operation example of FIG. 3, a wireless LAN mesh network (2) 100 ₂ belonging to Node (4)) the destination node extracted from the RREQ whether it is already learned node, the destination Confirmation is made based on whether or not the node address is the address of a node existing in the managed wireless LAN mesh network (step S103).

If the destination node is not a learned node in step S103 (step S103-No), it is determined that the destination node is not the RREQ to be processed, and the process of this flow ends.
On the other hand, if the destination node is a learned node in step S103 (step S103-Yes), it is confirmed whether this destination node belongs to a wireless LAN mesh network or Ethernet (registered trademark) different from the source node. (in the operation example of FIG. 3, the source node (1) is a wireless LAN mesh network (1) 100 _1, the destination node (4) belongs to a wireless LAN mesh network (2) 100 _2, the different networks Belong).
In step S104, if the destination node does not belong to any of the wireless LAN mesh network and Ethernet (registered trademark) different from the source node (step S104-No), it is considered that the router 21 is not the RREQ to be processed. Then, the process of this flow is finished.

As step S104-No case, (in the example of FIG. 3, a node (5) MPP13 ₆ of MPP13 ₅ or nodes (6)) of the router 21 MPP wireless LAN Field of the destination node indicated in RREQ received from There are cases where the mesh network is the same wireless LAN mesh network as the source node.
In this case, since the router 21 learns when receiving the RREQ transferred via the MPP 13 ₅ of the node (5) and the MPP 13 ₆ of the node (6), the destination node and the source node are both can be determined to belong to a wireless LAN mesh network (1) 100 ₁ or a wireless LAN mesh network (2) 100 ₂ of the same network, in this case, does not perform anything modes of operation. That is, the operation is normally performed in the wireless LAN mesh network, and the relay operation of the router 21 is not necessary.

On the other hand, in step S104, when the destination node belongs to a wireless LAN mesh network or Ethernet (registered trademark) different from the transmission source node (step S104-Yes), the router 21 sets this RREQ as a processing target according to the RREQ. The data exchange performed between the destination node and the transmission source node is relayed to construct the route, and the RREP for the RREQ is returned to the transmission source node (step S105). Note that the processing when the destination node belongs to Ethernet (registered trademark) in step S104 is an operation not directly related to the gist of the relay function of the present embodiment, and is omitted in the following description.
In step S105, the router 21 returns RREP to the transmission source node, and the processing according to this flow is completed. As a result of the processing by this flow, when the transmission source node receives the RREP returned in step S105, a data frame path to be transferred from the transmission source node to the destination node is constructed.

Here, the operation of data communication performed between the different wireless LAN mesh networks (1) 100 ₁ and (2) 100 ₂ based on the construction of the route by the router 21 will be described with reference to FIG. This will be described in detail. In the operation example of FIG. 3, the following operations (1) to (7) are performed in ascending order (indicated by (1) to (7) in FIG. 3).
Operation (1) Construction of a route between the wireless LAN mesh network to which the transmission source node belongs and the router 21 (RREQ reception / RREP transmission)
Operation (2) Data frame is transmitted by the route constructed in Operation (1) Operation (3) Ethernet frame reception by router 21 Operation (4) Source MAC address conversion Operation (5) Router 21 and destination node Construction of routes between wireless LAN mesh networks to which they belong (RREQ reception / RREP transmission)
Operation (6) Ethernet (registered trademark) frame transmission from router 21 Operation (7) Receive data frame via path constructed in operation (5)

Operation (1): As described above, the router 21 determines whether or not the wireless LAN mesh network to which the destination node indicated by the RREQ received from the MPP belongs is the same wireless LAN mesh network as the transmission source node. When this determination is made and a result is obtained that the destination node indicated in RREQ and the transmission source node belong to different wireless LAN mesh networks, the router 21 obtains the wireless LAN mesh network to which the transmission source node belongs (example in FIG. 3). Then, the wireless LAN mesh network (1) 100 ₁ ) operates as a temporary destination node (node (4) in the example of FIG. 3). That is, as a response operation to the previously received RREQ, the router 21 receives the destination address DA first, using the source address SA as the address of the destination node (node (4) in the example of FIG. 3). RREP as the source node (node (1)) of the received RREQ is returned to the MPP (MPP13 _{5 of the} node (5)).
The MPP that receives the RREP from the router 21 (MPP13 _{5 of the} node (5)) unicasts the RREP according to the destination address DA (node (1)) and reverses the communication path of the previous RREQ. Since the destination node (node (1)) that receives the RREP determines that the RREP has been returned from the destination node (node (4)), the route between the source node (node (1)) and the router 21 is now determined. Construction of is completed. When the router 21 has not learned the destination node (node (4)), the router 21 only performs address learning of the transmission source node (node (1)), and does not return RREP.

Operation (2): After constructing the route between the source node (node (1)) and the router 21 as described above, the source node (node (1)) passes through the constructed route, and the destination node The data frame is transmitted to the node (node (4)).
Operation (3): The MPP13 ₅ nodes on a wireless LAN mesh network Field of the source node (5), the following Ethernet 20 on the data frame to the router 21 according to the route of the constructed destination node Forward.
However, the node (5) transfer operation of the data frame MPP13 ₅ performs a is for the router 21 operating as actually tentatively determined destination node (node (4)). Therefore, MPP13 _5, when transferring the data frame to the router 12, the original source node that has been instructed to transmit source address SA to the wireless LAN mesh network frame (the node (1)) from the Ethernet (registered trademark) It is necessary to convert to the address of the MPP (node (5)) connected to the router 21 indicated by the frame.

Operation (4): However, the router 21 that receives the Ethernet (registered trademark) frame with the address of the MPP (node (5)) as the transmission source address SA leaves the transmission source address SA as it is, and the wireless LAN mesh network (2 ) To indicate the wrong source node, it is converted to the original correct source address SA. In this conversion, the router 21 receives the RREQ first and, like data communication from the source node (1) to the destination node (4), different wireless LAN mesh networks (1) 100 ₁ , (2) 100 Since it is known in advance that the data frame is transferred between the _two , as shown in the example of FIG. 3, the Ethernet (registered trademark) frame in which the source address SA is the node (5) and the destination address DA is the node (4). , The source address SA is converted into the node (1), and the source address SA is returned to the same as in the case of the wireless LAN mesh network frame. If the source address is the original source node before the router 21 performs source address translation, the router 21 does not perform source address translation.

Operation (5): Further, the router 21 performs a temporary transmission source node (node (1)) with respect to the wireless LAN mesh network to which the destination node belongs (in the example of FIG. 3, the wireless LAN mesh network (2) 100 ₂ ). ). That is, the operation to be relayed to the source node (Node 1) belongs wireless LAN mesh destination node RREQ received from the network (node (4)) belongs wireless LAN mesh network through MPP13 ₅ earlier to the node (5) As described above, the router 21 sets an RREQ that uses the source address SA as the address of the source node (node (1)) temporarily determined and the destination address DA as the destination node (node (4)) of the RREQ that has been received first. transmits through MPP13 ₆ nodes (6).
The destination node (node (4)) that has received the RREQ returns RREP in accordance with the existing on-demand routing protocol by reversely unicasting the communication path of the previous RREQ, and the MPP13 _{6 of the} node (6). Through the router 21. At this time, the router 21 operates as a temporary transmission source node (node (1)), and constructs a route between the destination node (node (4)) and the router 21.

Operation (6): Next, the router 21 follows the path constructed in the operation (5), and the MPP 13 of the node (6) on the wireless LAN mesh network (wireless LAN mesh network (2) 100 ₂ ) to which the destination node belongs. Ethernet (registered trademark) frame transmission to ₆ . At this time, since the source address SA has been converted to the original correct source address SA (node (1)) in the operation (4), the router 21 instructs the converted source address SA. That is, in the operation (2), the transmission source node (node (1)) transfers the data frame by giving the same instruction as the transmission source address SA and the destination address DA when the data frame is transferred.
Operation (7): Next, the MPP 13 ₆ that receives the Ethernet (registered trademark) frame transmits the received data frame to the wireless LAN to which the destination node (node (4)) belongs in accordance with the path constructed in the operation (5). When it is transferred to the next node on the mesh network (wireless LAN mesh network (2) 100 ₂ ) and finally the data frame is received by the destination node (node (4)), the data transmission is completed.

As described above, the router 21 learns in advance the address and the wireless LAN mesh network to which each node belongs, and transfers data from the source node (node (1)) illustrated in FIG. 3 to the destination node (node (4)). When communicating between different wireless LAN mesh networks (1) 100 ₁ and (2) 100 _{2 as in the} case of communication, it is as if the source and destination nodes exist in the same wireless LAN mesh network. In addition, a route in each wireless LAN mesh network is constructed by relaying a route request and a route response, and when data is transmitted, conversion is performed so that the address of the transmission source node is correctly transmitted to the receiving side. Relay.
By this relay operation, the nodes in the wireless LAN mesh network can transmit and receive data frames not only with nodes in the same wireless LAN mesh network but also with nodes in other wireless LAN mesh networks.

<Embodiment 2>
In this embodiment, as in the above <Embodiment 1>, an Ethernet (registered trademark) router has a relay function, but the operation modes of route request and route response are different.
In this embodiment, an Ethernet (registered trademark) router has a function of transferring RREQ and RREP between different wireless LAN mesh networks as a relay function, and this function allows RREQ to be performed within the same wireless LAN mesh network. And a route request and a route response for transmitting and receiving RREP are performed. In addition, since this difference is not different from the above <Embodiment 1>, the details of the same components are referred to the above description, and the description is omitted here.

FIG. 5 is a diagram for explaining the communication operation by the connection configuration of different wireless LAN mesh networks and the relay function of the router according to the second embodiment.
In the configuration shown in FIG. 5, different wireless LAN mesh wireless LAN mesh network (1) it is a network 100 ₁ and a wireless LAN mesh network (2) 100 ₂ are connected by the router 21. Each of the connected wireless LAN mesh networks includes the same components as those of the wireless LAN mesh network 100 described above with reference to FIG.

In the network having the configuration shown in FIG. 5, the data communication operation performed between the different wireless LAN mesh networks (1) 100 ₁ and (2) 100 ₂ according to the route constructed by the relay function of the router 21 is the same. This will be described in more detail with reference to the drawings. In the operation example of FIG. 5, the following operations (1) to (7) are performed in ascending order (indicated by (1) to (7) in FIG. 5).
Operation (1) RREQ transfer from the source node to the destination node Operation (2) RREP transfer from the destination node to the source node Operation (3) The data frame is transmitted through the path constructed in the operations (1) and (2). Transmission operation (4) Ethernet (registered trademark) frame reception by router 21 operation (5) Source MAC address conversion operation (6) Ethernet (registered trademark) frame transmission from router 21 operation (7) Data frame operation (1) Received via the route constructed in (2)

Operation (1): The STA 17 ₁ of the node (1) in the wireless LAN mesh network (1) 100 ₁ transfers a data frame to the STA 17 ₄ of the node (4) in the wireless LAN mesh network (2) 100 ₂ . In this case, first, the STA 17 ₁ of the node (1) broadcasts the RREQ.
However, since the STA 17 ₄ of the node (4) does not exist in the wireless LAN mesh network (1) 100 ₁ to which the node (1) belongs, the RREQ transferred by the node (1) is directly transferred to the node (4). I can't.
Accordingly, a wireless LAN mesh network (1) 100 nodes in _a (5) of MPP13 ₅ receives the RREQ from the router 21 is an Ethernet (registered trademark) wireless LAN mesh network (2) via a 20 to 100 in a _two-node ( the RREQ received in MPP13 ₆ of 6) transfers.
At this time, when the router 21 has already learned the destination node (node (4)) indicated by the RREQ transferred from the node (5), the router 21 receives the received RREQ as a radio to which the destination node (node (4)) belongs. transferred to the node of the LAN mesh network (2) 100 in ₂ (6).

Next, the node (6) is to broadcast transfer the RREQ from the received source node (Node 1) in a wireless LAN mesh network (2) 100 within _2, the destination node (node (4)), the RREQ can be received.
In this manner, the router 21 relays, MPP13 ₆ nodes (6) for receiving the RREQ transferred from the router 21, or such an operation is a RREQ performed within the same wireless LAN mesh network in can be transferred RREQ to the wireless LAN mesh network (2) 100 _2.

Operation (2): The destination node (node (4)) sets the RREP that uses the destination address DA as the transmission source node (node (1)) of the RREQ received in the operation (1) to the wireless LAN mesh network (2) 100. the path during reception of the RREQ in ₂ unicast forwarding Conversely, reply to the router 21 in MPP13 through ₆ of the node (6). Via MPP13 ₅ of nodes of a wireless LAN mesh network (1) 100 ₁ from the router 21 (5), be unicast forwarding to the contrary node path in the reception path is also the RREQ to reply (1) Therefore, by performing this transfer operation, the path construction between the transmission source node (node (1)) and the destination node (node (4)) is completed.

The operations (3) to (7) in this embodiment correspond to the operations (2), (3), (4), (6), and (7) in <Embodiment 1>, and the operation contents are the same. It is. Therefore, the description of the above <Embodiment 1> is referred to and the description is omitted here.
As described above, the router 21 learns in advance the wireless LAN mesh network to which each node address belongs, and transmits data from the source node (node (1)) illustrated in FIG. 5 to the destination node (node (4)). When communicating between different wireless LAN mesh networks 100 ₁ and 100 _{2 as} in communication, the route request and the route are as if the source and destination nodes exist in the same wireless LAN mesh network. By forwarding a response and relaying between different wireless LAN mesh networks, a route in each wireless LAN mesh network is constructed, and the address of the transmission source node is correctly transmitted to the receiving side even when data is transmitted. Perform conversion and relay data communication.
By this relay operation, the nodes in the wireless LAN mesh network can transmit and receive data frames not only with nodes in the same wireless LAN mesh network but also with nodes in other wireless LAN mesh networks.

<Embodiment 3>
This embodiment shows an example in which the MPP constituting the wireless LAN mesh network has a relay function between different wireless LAN mesh networks.
In the above <Embodiment 1> and <Embodiment 2>, the router 21 on the Ethernet (registered trademark) 20 is provided with the relay function. However, in this embodiment, the MPP that configures the wireless LAN mesh network has the above < The relay function of the router 21 of the first embodiment and the second embodiment is provided. That is, the MPP of this embodiment is a wireless module that functions only between wireless LAN mesh networks without connecting to an external network with a wired connection like an Ethernet (registered trademark) router. Allows connection between networks.

FIG. 6 is a diagram for explaining the communication operation by the connection configuration of different wireless LAN mesh networks and the MPP relay function according to the present embodiment.
In the configuration shown in FIG. 6, different wireless LAN wireless LAN mesh network (1) is a mesh network 100 ₁ and a wireless LAN mesh network (2) 100 ₂ are connected by MPP13r. Each connected wireless LAN mesh network is basically composed of the same components as the wireless LAN mesh network 100 described above with reference to FIG. 1 except for the MPP 13r.
The MPP 13r is a wireless module that functions as a portal point for different wireless LAN mesh networks, and can be connected to nodes such as MP11 of either wireless LAN mesh network.

The relay function between the wireless LAN mesh networks possessed by the MPP 13r is basically similar to the relay function of the above-described <Embodiment 1> and <Embodiment 2> router 21 from the source node to the destination between different wireless LAN mesh networks. The RREQ and RREP to the node are transferred to construct a route, and a data communication relay operation is performed according to the constructed route. In the example of FIG. 6, “STA17 _{1 of} node (1)” → “MAP12” → “MP11” → “MP11” → “MP11” → “MPP13r” → “MP11” → “MP11” → “MP11” → “MAP12” "→ order to construct a path between the wireless LAN mesh network (1) 100 ₁ and a wireless LAN mesh network (2) 100 _2" node (4) of the STA17 ₄ "performs a relay operation of the data communication.
In addition, it has means for managing and processing information such as node addresses necessary for the relay operation.
As described above, by performing the relay operation from the source node to the destination node between different wireless LAN mesh networks by the MPP 13r of the wireless module, the nodes in the wireless LAN mesh network are not limited to the nodes in the same wireless LAN mesh network. Data frames can be transmitted / received to / from nodes in other wireless LAN mesh networks. Further, the conversion to the Ethernet (registered trademark) frame and the conversion of the source MAC address, which are necessary in the above <Embodiment 1> and <Embodiment 2>, are not required at the time of relaying.

<Embodiment 4>
This embodiment shows another example implemented in a form having a relay function between wireless LAN mesh networks having different MPPs constituting the wireless LAN mesh network.
In the above <Embodiment 3>, an MPP in a shared form is shown, which is a wireless module that works as a portal point for different wireless LAN mesh networks and can be connected to nodes such as MP11 of either wireless LAN mesh network. In the case of taking this form, if it is attempted to keep different wireless LAN mesh networks in a connected state, the network configuration flexibility cannot be denied.
Therefore, an MPP as a wireless module serving as a portal point for different wireless LAN mesh networks is used as a component in each wireless LAN mesh network, and an interface that enables direct connection between the MPPs is provided in the MPP. To. By adopting such a configuration, the flexibility of the network configuration can be increased. If importance is attached to the network configuration, the connection between the MPPs may be wired.

FIG. 7 is a diagram for explaining a communication operation by a connection configuration of different wireless LAN mesh networks and an MPP relay function according to the present embodiment.
In the configuration shown in FIG. 7, the wireless LAN mesh network (1) 100 ₁ and the wireless LAN mesh network (2) 100 ₂ that are different wireless LAN mesh networks each have the MPP 13r, and the wireless LAN mesh networks that are different between the MPPs 13r. Connect. Each connected wireless LAN mesh network is basically composed of the same components as the wireless LAN mesh network 100 described above with reference to FIG. 1 except for the MPP 13r.
The MPP 13r of each wireless LAN mesh network has an interface that allows MPPs to be directly connected to each other, and can connect various nodes in different wireless LAN mesh networks via the MPP13r.

The relay function between the wireless LAN mesh networks possessed by the MPP 13r is basically similar to the relay function of the above-described <Embodiment 1> and <Embodiment 2> router 21 from the source node to the destination between different wireless LAN mesh networks. The RREQ and RREP to the node are transferred to construct a route, and a data communication relay operation is performed according to the constructed route. In the example of FIG. 7, “STA17 _{1 of} node (1)” → “MAP12” → “MP11” → “MP11” → “MAP12” → “MPP13r” → “MPP13r” → “MAP12” → “MP11” → “MP11” → "MAP12" → order to construct a path between the wireless LAN mesh network (1) 100 ₁ and a wireless LAN mesh network (2) 100 ₂ "node (4) of the STA17 _4" performs a relaying operation of the data communication .
Further, the MPP 13r has means for performing information management and processing such as node addresses necessary for the relay operation.
As described above, by performing the relay operation from the source node to the destination node between different wireless LAN mesh networks by the MPP 13r of the wireless module included in each wireless LAN mesh network, the nodes in the wireless LAN mesh network can be connected to the same wireless LAN mesh network. Data frames can be transmitted and received not only with nodes in the network but also with nodes in other wireless LAN mesh networks. Further, the conversion to the Ethernet (registered trademark) frame and the conversion of the source MAC address, which are necessary in the above <Embodiment 1> and <Embodiment 2>, are not required at the time of relaying.

<Embodiment 5>
This embodiment relates to address management of nodes constituting a wireless LAN mesh network.
In order to realize the above-described relay function between different wireless LAN mesh networks, address management of nodes constituting the wireless LAN mesh network is required (refer to the description of the route construction processing in the flowchart of FIG. 4).
This address management is performed by the router 21 or MPP 13r, which is a device having a relay function, registering the addresses of nodes on the usable wireless LAN mesh network in the form of an address table. In the following description, a device having a relay function is described as the router 21, but the same can be applied to the MPP13r.

The router 21 needs to prepare an address table indicating the current state of the nodes on the wireless LAN mesh network. For example, the router 21 updates the address table normally in 300 seconds. On the other hand, the node side in the wireless LAN mesh network transmits the route request frame to the router 21 by unicast at regular intervals, thereby reflecting the current state in the update processing performed by the router.
This is because if a node in the wireless LAN mesh network does not transmit a route request frame for 300 seconds when the address table is updated, it is deleted from the entry in the address table managed by the router 21. .

For this reason, the node in the wireless LAN mesh network transmits a route request frame to the router 21 at intervals of 300 seconds or less, so that the current state is reflected in the periodic update of the address table.
At this time, since the route request frame transmitted by the node on the wireless LAN mesh network is used for updating the address table of the router 21, the router 21 does not need to send back a route response frame. For example, the node that performs this procedure transmits a route request frame that describes its own address in the destination address, and the router 21 that receives this transmits a route request frame in which both the destination address and the source address are the source nodes. When received, the address table is updated with the address indicated in the frame. In this case, the route response frame is not returned.
By performing address management of the nodes constituting the wireless LAN mesh network as described above, it is possible to quickly construct an accurate route.

11, 11 ₄ , 11 ₅ , 11 ₆ , 11 ₇ , 11 ₉ ... MP, 12, 12 ₃ , 12 ₁₀ ... MAP, 13, 13 ₅ , 13 ₆ , 13 ₈ , 13 _r . 17 ₁ , 17 ₂ , 17 ₄ ... STA, 20... Ethernet (registered trademark), 21, 21 ₁ ... Router, 100, 100 ₁ , 100 ₂ .

Japanese Patent No. 4406377

Claims (13)

A relay device that relays data communication performed by each of the constituent nodes of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol,
Address learning means for learning addresses of nodes in the network;
Relay necessity confirmation means for confirming whether or not relaying is necessary depending on whether or not the destination node indicated in the received route request exists in the network to which the transmission source node belongs;
First communication path determination means for determining a communication path between a transmission source node and a relay in the network to which the transmission source node belongs, on the condition that the relay necessity confirmation means confirms that relay is necessary;
On the condition of the confirmation, a second communication path determining means for determining a communication path between the relay station in the network to which the communication destination node belongs and the destination node;
A source address for converting an address of a source node instructed with respect to received data into an original address when data communication is relayed on the path determined by the first communication path determination unit and the second communication path determination unit And a conversion means. A relay device that relays data communication performed by each of the constituent nodes of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol,
Address learning means for learning addresses of nodes in the network;
Relay necessity confirmation means for confirming whether or not relaying is necessary depending on whether or not the destination node indicated in the received route request exists in the network to which the transmission source node belongs;
A series of communications between the source node and the destination node from the network to which the source node belongs to the network to which the destination node belongs via the relay device on the condition that the relay necessity confirmation means confirms that the relay is necessary A communication route determining means for determining a route;
Transmission source address conversion means for converting the address of the transmission source node instructed with respect to the received data into the original address when relaying data communication on the path determined by the communication path determination means, Repeater. In the repeater according to claim 1 or 2,
A repeater having an interface for connecting to an MPP (mesh portal point) of an ad hoc wireless LAN mesh network through a wired LAN. An MPP (mesh portal point) of a constituent element of the network that relays communication performed between the constituent elements of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol,
Address learning means for learning addresses of nodes in the network;
Relay necessity confirmation means for confirming whether or not relaying is necessary depending on whether or not the destination node indicated in the received route request exists in the network to which the transmission source node belongs;
A communication path between the source node and the destination node from the network to which the source node belongs to the network to which the destination node belongs via the MPP is provided on the condition that the relay necessity confirmation unit confirms that the relay is necessary. An MPP comprising: a communication path determining means for determining. In the MPP as claimed in claim 4,
An MPP having an interface for directly connecting to an MPP of an ad hoc wireless LAN mesh network to be relayed.   The address learning means, the relay necessity confirmation means, the first communication path determination means, the second communication path determination means, the transmission source address conversion means of the relay device according to claim 1 or 3, Program to function as each means of interface.   A program for causing a computer to function as each of the address learning means, the relay necessity confirmation means, the communication route determination means, the transmission source address conversion means, and the interface of the relay apparatus according to claim 2 or 3. .   A program for causing a computer to function as each of the address learning means, the relay necessity confirmation means, the communication path determination means, and the interface of the MPP according to claim 4 or 5.   A computer-readable recording medium on which the program according to claim 6 is recorded.   4. A data communication network configured by connecting MPPs (mesh portal points) configuring different ad hoc wireless LAN mesh networks via a relay device according to any one of claims 1 to 3.   A data communication network configured by connecting different ad hoc wireless LAN mesh networks via the MPP according to claim 4 or 5. An inter-network communication method for relaying data communication performed between nodes of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol,
An address learning step of receiving a route request issued by a source node specifying a destination node and learning an address of a node in the network;
A relay necessity confirmation step for confirming whether or not relaying is necessary depending on whether the destination node indicated in the received route request exists in the network to which the transmission source node belongs;
A first communication path determination step for determining a communication path between a transmission source node and a relay in the network to which the transmission source node belongs, on the condition that the relay necessity confirmation step confirms that the relay is necessary;
A second communication path determination step for determining a communication path between the relay station in the network to which the destination node of the relayed communication belongs and the destination node via the communication path determined in the first communication path determination step;
A source address that converts the address of the source node that is instructed for the received data into the original address when data communication is relayed on the route determined by the first communication route determination step and the second communication route determination step An inter-network communication method characterized by performing a conversion step. An inter-network communication method for relaying data communication performed between nodes of different ad hoc wireless LAN mesh networks according to an on-demand routing protocol,
An address learning step of receiving a route request issued by a source node specifying a destination node and learning an address of a node in the network;
A relay necessity confirmation step for confirming whether or not relaying is necessary depending on whether the destination node indicated in the received route request exists in the network to which the transmission source node belongs;
A series of communications between the source node and the destination node from the network to which the source node belongs to the network to which the destination node belongs through the relay machine on the condition that the relay necessity confirmation step confirms that the relay is necessary A communication route determination step for determining a route;
Performing a transmission source address conversion step of converting an address of a transmission source node instructed with respect to received data into an original address when relaying data communication on the route determined by the communication route determination step. To communicate between networks.

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