JP6558728B2 - Wireless mesh network system - Google Patents

Description

  The present invention relates to a wireless mesh network system.

  In a wireless mesh network by a plurality of wireless LAN access points (hereinafter referred to as “access points”), traffic is an access point between an Internet gateway and a user terminal. Since it is transferred via the wireless link (wireless backbone network) between the wireless communication, the wireless traffic interference and frame collision with the nearby wireless link and CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) ) Waiting time associated with collision avoidance control increases. As a result, the channel occupation time allocated for data transmission / reception decreases, and the backbone network capacity decreases. In order to solve such a decrease in network capacity, a method of assigning different channels to radio links that interfere with each other on the backbone network (see, for example, Non-Patent Document 1), or separating user traffic via different channels or spatially In addition, path control via access points (for example, see Non-Patent Document 2), MAC protocol (Media Access Control Protocol) for controlling channel occupancy of each access point (for example, see Non-Patent Document 3), and the like have been proposed. .

A. Raniwala and T. Chiueh, "Architecture and algorithms for an IEEE 802.11-based multi-channel wireless mesh network", Proceedings of the 24th Annual IEEE International Conference on Computer Communications, pp.2223-2234, INFOCOM, 2005 S. Mustafa SA Madani, K. Hayat, and SU Khan, "Stable-path multi-channel routing with extended level channel assignment", International Journal of Communication System, vol.56, no.2, pp.940-965, Feb . 2012 J. So and NH Vaiya, "Multi-channel Mac for Ad Hoc Networks: Handling Multi-channel Hidden Terminals Using a Single Transceiver", Proceedings of the 5th ACM International Symposium on Mobile Ad Hoc Networking and Computing, pp.222-233, MobiHoc, 2004

  However, in the above-described method and the like, the route control and channel assignment of the wireless backbone network are closely related, and thus the two methods depend on each other. Since the route control method and the channel assignment method perform path switching based on the existing route table, all traffic whose destination is the same entry in the route table is transferred through the same path. In addition, the route table is the next hop (at a distance where radio transmission / reception can be directly performed), and even if there are multiple radio links on different channels, only one link can be specified and can be specified simultaneously. It is difficult to effectively use a plurality of channels. Furthermore, in the case of assuming a plurality of channels, the number of radio interfaces (the number of channels) is limited due to hardware configuration restrictions, and the channels that can be used in parallel are limited. For this reason, the network capacity of the wireless backbone network cannot be increased sufficiently.

  The main purpose of the wireless communication system of the present invention is to increase the network capacity of the wireless backbone network.

  The wireless mesh network system of the present invention adopts the following means in order to achieve the main object described above.

The first wireless mesh network system of the present invention is:
A wireless mesh network system,
By connecting multiple wireless access points in a wired or wireless manner, the same number of channels as the number of wireless access points can be used simultaneously, and multiple virtual wireless access points functioning as wireless mesh network access points;
A control device for setting a data transfer path in a wireless mesh network and a use channel in the data transfer path;
It is a summary to provide.

  In the first wireless mesh network system of the present invention, a plurality of virtual wireless access points as access points of the wireless mesh network, a data transfer path in the wireless mesh network, and a control device for setting a use channel in the data transfer path, Is provided. The virtual wireless access point is configured by connecting a plurality of wireless access points in a daisy chain by wire or wirelessly, and the same number of channels as the number of wireless access points can be used simultaneously. Therefore, a plurality of channels can be used simultaneously for data transfer, and the network capacity of the wireless backbone network can be dramatically increased.

  In the first wireless mesh network system of the present invention, the plurality of virtual wireless access points have an open flow switch function, and the control device sets a data transfer path and a use channel by the open flow controller function. You can also In this case, when the control device receives a packet with an undefined flow, the control device uses at least the IP address of the transmission source, the IP address of the destination, the transmission port number, among the identification information of layers 1 to 4, A flow is defined using a reception port number, and the virtual wireless access point transmits the packet to the control device for a packet for which the flow is undefined, and to the flow for a packet for which the flow is defined. The packet may be transmitted through a usage channel based on it. Thus, by using OpenFlow in a wireless mesh network using virtual wireless access points, simultaneous use of a plurality of channels for data transfer can be facilitated.

  In the first wireless mesh network system of the present invention using such an open flow, each time the flow is defined, the control device sets the use channel so that transmission is sequentially performed on different channels among a plurality of available channels. It can also be defined in a flow. In this way, since different channels among the plurality of channels are sequentially defined in the flow as usage channels, more even usage of each channel can be promoted, and the network capacity of the wireless backbone network can be further increased.

  In the first wireless mesh network system of the present invention in which different channels are sequentially defined as usage channels for each flow, the control device flows the usage channels so that they are transmitted on the same channel in the data transfer path. The control device can also define the usage channel as a flow so that it is transmitted on a different channel every time it hops in the data transfer path. In the latter case, further equal utilization of each channel can be promoted, and the network capacity of the wireless backbone network can be increased.

  Further, in the first wireless mesh network system of the present invention using an open flow, the virtual wireless access point aggregates and holds a traffic amount within a predetermined time as a traffic amount transmitted / received within a predetermined time on each channel. The control device obtains the traffic volume within the predetermined time for each virtual wireless access point, and defines a flow with the channel having the minimum traffic volume within the predetermined time as the use channel. It can also be. In this way, since a channel with a small amount of traffic within a predetermined time is used as a use channel, more even use of each channel can be promoted, and the network capacity of the wireless backbone network can be further increased. Here, 10 msec, 100 msec, 1000 msec, etc. can be used as the “predetermined time”. The same applies to the following “predetermined time”.

  In the first wireless mesh network system of the present invention using an open flow, the virtual wireless access point aggregates and holds the traffic amount within a predetermined time as the traffic amount transmitted / received within each channel through the predetermined time. The control device obtains the traffic amount within the predetermined time for each virtual wireless access point, and sums the traffic amount within the predetermined time of the virtual wireless access points belonging to the predetermined range for each channel. It is also possible to calculate the amount of traffic within a predetermined range for each channel and define a channel in which the traffic amount within the predetermined range is minimum as the usage channel in the flow. In this way, since a channel with a small amount of traffic within a predetermined range is used as a use channel, more even use of each channel can be promoted, and the network capacity of the wireless backbone network can be further increased. Here, as the “predetermined range”, a range in which radio waves reach in radio transmission (interference range), a range of adjacent virtual radio access points, and the like can be used. The same applies to the “predetermined range” below.

  In the first wireless mesh network system of the present invention using an open flow, the virtual wireless access point aggregates and holds the traffic amount within a predetermined time as the traffic amount transmitted / received within each channel through the predetermined time. The control device obtains, for each virtual wireless access point, (A1) the amount of traffic within the predetermined time from the virtual wireless access point, and (B1) is transmitted on the channel with the maximum amount of traffic within the predetermined time. It is also possible to select one flow from a group of flows and to change the use channel so that the selected flow is transmitted through a channel having a minimum traffic amount within a predetermined time. In this way, even when the traffic amount of the channel within a predetermined time changes with the passage of time, more even use of each channel can be promoted, and the network capacity of the wireless backbone network can be further increased. .

  In the first wireless mesh network system of the present invention in which the usage channel is changed based on the traffic volume within a predetermined time period, the virtual wireless access point receives the traffic volume for each flow transmitted and received within the predetermined time period on each channel. And the control device acquires the flow traffic volume together with the traffic volume within the predetermined time in (A1), and the predetermined flow rate between channels in (B1). A flow having the flow traffic amount closest to a value obtained by calculating a difference between channels as a difference in intra-hour traffic amount and multiplying the maximum inter-channel difference by a predetermined coefficient among the calculated inter-channel differences is defined as the one flow. It can also be selected. In this way, the traffic volume of each channel can be made more evenly efficiently. Here, the predetermined coefficient is a value larger than the value 0 and smaller than the value 1, and preferably around 0.5. This is based on the fact that the inter-channel difference can be canceled by changing the use channel of the flow having the flow traffic amount ½ of the maximum inter-channel difference.

  Further, in the first wireless mesh network system of the present invention in which the use channel is changed based on a traffic amount within a predetermined time, the control device is configured to determine, in (B1), the largest of the calculated inter-channel differences. When the inter-channel difference is less than a predetermined value, the use channel of the selected flow may not be changed. In this way, unnecessary changes in the usage channel can be suppressed. Here, the predetermined value is used to determine whether or not the change of the channel used for the flow is necessary because the difference between the channels is large, and is determined as appropriate depending on the wireless communication capacity and the predetermined time.

  In the first wireless mesh network system of the present invention in an aspect using OpenFlow, the virtual wireless access point aggregates and holds the transmission traffic amount as the traffic amount transmitted within a predetermined time in each channel, The control device obtains (A2) the amount of transmission traffic for each virtual wireless access point VAP, and (B2) sums the amounts of transmission traffic of each channel of each virtual wireless access point belonging to a predetermined range. Calculating a traffic amount within a predetermined range for each channel and calculating an inter-channel difference as a difference between channels of the traffic amount within the predetermined range; (C2) among the virtual wireless access points belonging to the predetermined range; For the virtual wireless access point with the largest difference, Selecting one flow from a group of flows transmitted on a channel with the maximum amount of traffic within a fixed range, and changing a use channel so that the selected flow is transmitted on a channel with a minimum amount of traffic within a predetermined range; It can also be. In this way, even if the transmission traffic amount of the channel changes with the passage of time, each channel can be used more evenly in data transfer as the entire data transfer path.

  In the first wireless mesh network system of the present invention in which the use channel is changed based on a traffic amount within a predetermined time between channels of the virtual wireless access point belonging to the predetermined range, the virtual wireless access point is The transmission flow traffic volume as the traffic volume of each flow transmitted within the predetermined time is aggregated and held, and the control device obtains the transmission flow traffic volume together with the transmission traffic volume in (A2). In (C2), when there is a flow having a transmission flow traffic amount within a predetermined coefficient range obtained by multiplying the maximum inter-channel difference among the inter-channel differences by a predetermined coefficient, the transmission flow traffic amount is The flow closest to the upper limit of the coefficient range Performed changes use channels of flow that the selected select as a flow, when the flow of the flow traffic quantity within the predetermined coefficient range is not present not change the use channel may be a thing. In this way, the traffic amount within the predetermined range of each channel can be made more uniform. Here, the predetermined coefficient is a value larger than the value 0 and smaller than the value 1, and preferably around 0.5. This is based on the fact that the inter-channel difference can be canceled by changing the use channel of the flow having the flow traffic amount ½ of the maximum inter-channel difference.

  Further, in the first wireless mesh network system of the present invention in which a use channel is changed based on a traffic amount within a predetermined time between channels of virtual wireless access points belonging to a predetermined range, the control device includes: (D2) In the virtual wireless access point where the inter-channel difference is maximized, when the use channel is changed, the flow traffic amount of the flow related to the change is subtracted from the transmission traffic amount of the channel before the change, and the transmission traffic amount of the channel after the change is changed. (E2) delete the virtual wireless access point that is the target of the virtual wireless access point with the maximum difference between channels in (C2) from the target of the virtual wireless access point of (C2), and (F2 ) (B2) to (E2) are changed to the channel of (C2). During differential is repeated until the absence of target virtual wireless access point having the maximum, it may be a thing. In this way, it is possible to use each channel more evenly in data transfer within a predetermined range in the data transfer path regardless of the passage of time. In this case, the control device can repeat (G2) (B2) to (F2) a predetermined number of times or until the inter-channel difference at each virtual wireless access point becomes a predetermined value or less. This makes it possible to use each channel more evenly in data transfer as the entire data transfer path regardless of the passage of time.

The second wireless mesh network system of the present invention is:
A wireless mesh network system,
A plurality of wireless access points that can simultaneously use a plurality of channels, have an open flow switch function, and function as an access point of a wireless mesh network;
A control device for setting a data transfer path in a wireless mesh network and a use channel in the data transfer path by an open flow controller function;
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow.
This is the gist.

  In the second wireless mesh network system of the present invention, a plurality of wireless access points having an open flow switch function and capable of simultaneously using a plurality of channels function as access points of the wireless mesh network. Further, the control device sets a data transfer path in the wireless mesh network and a use channel in the data transfer path by the OpenFlow controller function. When the control device receives a packet with an undefined flow, the control device uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 A wireless access point transmits a packet to a control device for a packet for which the flow is undefined, and transmits a packet using a channel based on the flow for a packet for which the flow is defined. . For this reason, by using OpenFlow in a wireless mesh network using wireless access points, multiple channels can be easily used simultaneously for data transfer, and the network capacity of the wireless backbone network can be dramatically increased. .

  In such a second wireless mesh network system of the present invention, each time the control device defines a flow, the control device defines the use channel in the flow so that transmission is sequentially performed on different channels among the plurality of available channels. It can also be. In this way, since different channels among the plurality of channels are sequentially defined in the flow as usage channels, more even usage of each channel can be promoted, and the network capacity of the wireless backbone network can be further increased.

  Further, in the second wireless mesh network system of the present invention, the virtual wireless access point aggregates and holds the traffic amount within a predetermined time as the traffic amount transmitted / received within each predetermined channel in each channel, and the control The apparatus may acquire the traffic amount within a predetermined time period for each virtual wireless access point, and define a flow with the channel having the minimum traffic amount within the predetermined time period as the use channel. In this way, since a channel with a small amount of traffic within a predetermined time is used as a use channel, more even use of each channel can be promoted, and the network capacity of the wireless backbone network can be further increased. Here, 10 msec, 100 msec, 1000 msec, etc. can be used as the “predetermined time”. The same applies to the following “predetermined time”.

  In the second wireless mesh network system of the present invention, the wireless access point aggregates and holds a traffic amount within a predetermined time as a traffic amount transmitted / received within a predetermined time in each channel, and the control device includes: For each wireless access point, the amount of traffic within the predetermined range is acquired, and the amount of traffic within the predetermined range for each channel is obtained by summing the amount of traffic within the predetermined time of virtual wireless access points belonging to the predetermined range for each channel. In addition to calculation, a channel that minimizes the amount of traffic within a predetermined range may be defined in the flow as the usage channel. In this way, since a channel with a small amount of traffic within a predetermined range is used as a use channel, more even use of each channel can be promoted, and the network capacity of the wireless backbone network can be further increased. Here, as the “predetermined range”, a range in which radio waves reach in radio transmission (interference range), a range of adjacent wireless access points, and the like can be used. The same applies to the “predetermined range” below.

  In the second wireless mesh network system of the present invention, the wireless access point aggregates and holds a traffic amount within a predetermined time as a traffic amount transmitted / received within a predetermined time in each channel, and the control device includes: For each wireless access point, (A1) obtain the traffic amount within the predetermined time from the wireless access point, and (B1) select one flow from the flow group transmitted on the channel with the maximum traffic amount within the predetermined time. In addition to the selection, the use channel may be changed so that the selected flow is transmitted through the channel having the minimum traffic amount within a predetermined time. In this way, even when the traffic amount of the channel within a predetermined time changes with the passage of time, more even use of each channel can be promoted, and the network capacity of the wireless backbone network can be further increased. .

  In the second wireless mesh network system of the present invention, the wireless access point aggregates and holds the amount of transmission traffic as the amount of traffic transmitted within a predetermined time on each channel, and the control device For the access point, (A2) obtain the transmission traffic volume, and (B2) calculate the traffic volume within the predetermined range for each channel by summing the transmission traffic volume of each channel of each wireless access point belonging to the predetermined range. And calculating an inter-channel difference as a difference between channels of the traffic amount within the predetermined range, and (C2) for the wireless access point having the maximum inter-channel difference among the wireless access points belonging to the predetermined range. , The amount of traffic within the specified range is transmitted on the channel with the maximum It is also possible to select one flow from the flow group and change the use channel so that the selected flow is transmitted through the channel having the smallest traffic amount within the predetermined range. In this way, even if the transmission traffic amount of the channel changes with the passage of time, each channel can be used more evenly in data transfer as the entire data transfer path.

  In the first wireless mesh network system or the second wireless mesh network system of the present invention using an open flow, the control device includes a channel group including at least one channel and mainly not transmitting / receiving. A and a group B including at least one channel that is mainly used for transmission / reception, so that a new flow is transmitted on a channel having the maximum transmission rate among the channels belonging to group A. The usage channel may be defined. In this way, a more appropriate usage channel can be defined for a new flow whose transfer rate is unknown.

  In the first wireless mesh network system or the second wireless mesh network system of the present invention using an open flow, the control device includes a channel group including at least one channel and mainly not transmitting / receiving. A and a group B of channels including at least one channel that is mainly transmitted and received, and the value of the number of flows flowing through the transmission rate among the channels belonging to group A with respect to the new flow The utilization channel may be defined such that an expected value obtained by dividing by 1 is transmitted on the maximum channel. In this way, a more appropriate usage channel can be defined for a new flow whose transfer rate is unknown.

  In the first or second wireless mesh network system according to the present invention, the channel having the maximum transmission rate or the channel having the maximum expected value among the channels belonging to group A for the new flow is defined as the use channel. As an initial value, the apparatus may distinguish the channel having the lowest transmission rate into the group B and distinguish the remaining channels into the group A. In this way, the channel with the maximum transmission rate can be group A and the channel with the minimum transmission rate can be group B.

  In the first or second wireless mesh network system according to the present invention, the channel having the maximum transmission rate or the channel having the maximum expected value among the channels belonging to group A for the new flow is defined as the use channel. When a new flow is transmitted / received on a channel belonging to group B with respect to a new flow whose usage channel is defined for a channel belonging to group A, the apparatus transmits a new flow to the channel having the maximum channel utilization rate of 100% or less. The usage channel can be changed. In this way, flows can be sequentially aggregated into some of the channels of group B. Here, the channel utilization rate is the ratio of the sum of the channel occupation times of each flow within a predetermined time to the target channel with respect to the predetermined time. The channel having the maximum channel utilization rate of 100% or less means the channel having the maximum sum of the channel occupation times of each flow within a predetermined time. In other words, the channel utilization rate (100−channel utilization rate). Is a channel that minimizes the remaining time obtained by subtracting the sum of the channel occupation times of each flow from a predetermined time. The channel usage rate is also agreed below.

  In the first or second wireless mesh network system of the present invention according to this aspect, the control device changes a use channel to a group B channel for a new flow in which a use channel is defined for a channel belonging to group A. When this is not possible, the channel defined in the flow as the use channel for the new flow may be changed to group B. In addition, when there are two or more channels belonging to group B and there are channels that are not transmitted / received among the channels belonging to group B, the control device performs transmission / reception among the channels belonging to group B. An unassigned channel may be changed to group A. In this way, the group B can be distinguished and the channel of the group A can be secured as necessary.

  In the first wireless mesh network system or the second wireless mesh network system of the present invention using an open flow, the control device is not used for transmission / reception among a plurality of available channels for a new flow. The usage channel may be defined so that the channel with the highest residual rate is transmitted. In this way, a more appropriate usage channel can be defined for a new flow whose transfer rate is unknown. Here, the residual rate is a value obtained by subtracting a transfer rate of a flow being transmitted / received from a transmission rate with respect to a target channel, and a transfer rate that can be further transmitted / received through the target channel.

  In the first wireless mesh network system or the second wireless mesh network system of the present invention using an open flow, the control device assigns transmission rates of a plurality of available channels to each channel for a new flow. The usage channel may be defined such that an expected value obtained by dividing the number of flowing flows by a value obtained by adding the value 1 is transmitted on the maximum channel. In this way, a more appropriate usage channel can be defined for a new flow whose transfer rate is unknown.

  In the first or second wireless mesh network system of the present invention in which a channel having a maximum residual rate or a channel having a maximum expected value is defined as a usage channel for a new flow, the control device defines the usage channel. The used channel may be changed to a channel having a maximum channel utilization rate of 100% or less when a new flow is transmitted / received through a channel different from the used channel. In this way, the flows can be aggregated sequentially to some of all channels.

It is a block diagram which shows the outline of a structure of the wireless mesh network system 20 as 1st Example of this invention. It is a block diagram which shows the outline of a structure in the data transfer path | route from the mobile terminal 12 to the internet 10 in FIG. It is a block diagram which shows the outline of a structure in case each of the virtual wireless access points VAP1-VAP4 in FIG. 2 is comprised by two wireless LAN access points AP. It is a flowchart which shows an example of the utilization channel definition method of the definition method 1. It is explanatory drawing which shows a mode that a channel is allocated by the utilization channel definition method of the definition method 1. FIG. It is a flowchart which shows an example of the utilization channel definition method of the definition method 2. It is explanatory drawing which shows a mode that a channel is allocated by the utilization channel definition method of the definition method 2. FIG. It is a flowchart which shows an example of the utilization channel definition method of the definition method 3. It is explanatory drawing which shows a mode that a channel is allocated by the utilization channel definition method of the definition method 3. FIG. It is explanatory drawing which shows a mode that a channel is allocated by the utilization channel definition method of the definition method 3. FIG. It is a flowchart which shows an example of the utilization channel definition method of the definition method 4. It is a flowchart which shows the utilization channel definition method of the definition method 4 when all the virtual radio | wireless access points VAP in a data transfer path | route become the predetermined range (interference range). It is explanatory drawing which shows a mode that a channel is allocated by the utilization channel definition method of the definition method 4. FIG. It is a flowchart which shows an example of the utilization channel change method of the change method 1. FIG. FIG. 4 is an explanatory diagram showing a state in which two data transmissions are assigned to a channel from the mobile terminal 12 in the configuration of FIG. 3 and transmitted. Explanation of how channels are allocated by the definition channel 3 using channel definition method when data is transmitted from the mobile terminal 13 to the Internet gateway IGW through the virtual wireless access points VAP3, VAP4 in the state of FIG. FIG. It is explanatory drawing which shows a result when a use channel is changed by the use channel change method of the change method 1 in the state of FIG. It is a flowchart which shows an example of the utilization channel change method of the change method 2. FIG. It is a flowchart which shows the utilization channel definition method of the change method 2 when all the virtual radio | wireless access points VAP in a data transfer path | route become the predetermined range (interference range). It is explanatory drawing which shows a result when a utilization channel is changed by the utilization channel change method of the change method 2 in the state of FIG. It is explanatory drawing which shows the method of the experiment 1 typically. FIG. 6 is an explanatory diagram showing the results of Experiment 1. It is explanatory drawing which shows the method of the experiment 2 typically. FIG. 10 is an explanatory diagram showing the results of Experiment 2. It is explanatory drawing which shows the method of the experiment 3 typically. It is explanatory drawing which shows the result of the experiment 3. FIG. It is a flowchart which shows an example of the utilization channel definition method of the definition method 5. It is a flowchart which shows an example of the utilization channel change method of the change method 3. FIG. It is explanatory drawing which shows a mode that a channel is allocated by the utilization channel definition method of the definition method 5. FIG. It is explanatory drawing which shows a mode that a utilization channel is changed with the utilization channel change method of the change method 3 with respect to FIG. It is explanatory drawing which shows a mode that a channel is allocated by the utilization channel definition method of the definition method 5 with respect to FIG. It is explanatory drawing which shows a mode that a utilization channel is changed with the utilization channel change method of the change method 3 with respect to FIG. It is explanatory drawing which shows a mode that a channel is allocated with the utilization channel definition method of the definition method 5 with respect to FIG. It is explanatory drawing which shows a mode that a utilization channel is changed with the utilization channel change method of the change method 3 with respect to FIG. It is explanatory drawing which shows a mode that a channel is allocated to the new flow by the utilization channel definition method of the definition method 5 before calculation required time passes with respect to FIG. It is explanatory drawing which shows the result of the experiment 4. It is a flowchart which shows an example of the utilization channel definition method of the definition method 6. It is a flowchart which shows an example of the utilization channel change method of the change method 4. FIG. It is explanatory drawing which shows a mode that a utilization channel is changed with the utilization channel change method of the change method 4 with respect to FIG. It is explanatory drawing which shows a mode that a channel is allocated with the utilization channel definition method of the definition method 6 with respect to FIG. It is explanatory drawing which shows a mode that a utilization channel is changed with the utilization channel change method of the change method 4 with respect to FIG. It is explanatory drawing which shows a mode that a channel is allocated with the utilization channel definition method of the definition method 6 with respect to FIG. It is explanatory drawing which shows a mode that a utilization channel is changed with the utilization channel change method of the change system 4 with respect to FIG.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a block diagram showing an outline of the configuration of a wireless mesh network system 20 according to the first embodiment of the present invention. The wireless mesh network system 20 according to the first embodiment includes a wireless mesh network 22 configured in a mesh shape with a plurality of virtual wireless access points VAP as access points, wirelessly connected to the wireless mesh network 22, and wired to the Internet 10. A plurality of connected Internet gateways IGW; a data transfer path in the wireless mesh network 22; and an open flow controller OFC for setting a use channel in the data transfer path. The mobile terminal 12 is connected to the Internet via the wireless mesh network 22. 10 is configured as a system connected to the network.

  As shown in the lower right in the figure, each virtual wireless access point VAP is connected to a plurality of wireless LAN access points AP in a daisy chain so as to be able to transmit and receive each other by wire. It is configured as an access point that can use the same number of channels simultaneously, and implements the OpenFlow switch (OpenFlow switch) function in OpenFlow. Each wireless LAN access point AP is configured as a known wireless device capable of wireless transmission / reception in a predetermined frequency band. In addition, each virtual wireless access point VAP stores the number of transmission packets and the number of bytes of transmission packets in each channel for a predetermined time, and based on this, the amount of transmission traffic and reception of data transmitted and received in each channel within a predetermined time The traffic volume, the transmission traffic volume (transmission flow traffic volume) and the reception traffic volume (reception flow traffic volume) for each flow in which data is transmitted and received within a predetermined time in each channel are aggregated and held. In the following description, the sum of the transmission traffic amount and the reception traffic amount is referred to as a predetermined time traffic amount, and the sum of the transmission flow traffic amount and the reception flow traffic amount is referred to as a flow traffic amount.

  The OpenFlow controller OFC is configured by executing software having an OpenFlow controller (OpenFlow controller) function in OpenFlow (OpenFlow) on a general-purpose computer, and packets with undefined flows from each virtual wireless access point Is received, the flow is defined by writing the data transfer path in the wireless mesh network 22 and the channel used in this data transfer path into the flow table. A flow can be defined by a combination of identification information of layers 1 to 4 (12 types in OpenFlow 1.0 and 15 types in OpenFlow 1.1). In the first embodiment, the source IP address and destination IP are used as matching rules. Address, transmission port number, and reception port number are mainly used, and MAC / IP address rewriting and output port designation are used as actions. Since the present invention essentially uses a plurality of channels in the data transfer path, the data transfer path is set by a known method or an unknown method that will be developed in the future. A detailed description of the setting will not be given.

  In FIG. 1, the data transfer path from the mobile terminal 12 to the Internet 10 set by the OpenFlow controller OFC by a well-known method is shown as the lower right number of the virtual wireless access point VAP. FIG. 2 is a block diagram showing an outline of the configuration of the data transfer path from the mobile terminal 12 to the Internet 10 in FIG. 1, and FIG. 3 shows that each of the virtual wireless access points VAP1 to VAP4 in FIG. It is a block diagram which shows the outline of a structure in case it is comprised by the access point AP. As shown in FIG. 1, the data transfer path from the mobile terminal 12 to the Internet 10 includes the lower center virtual wireless access point VAP1, the middle middle virtual wireless access point VAP2, the middle left virtual wireless access point VAP3, the upper left The virtual wireless access point VAP4 and the left internet gateway IGW are provided. In this data transfer path, the same number of channels as the number of wireless LAN access points AP of channel A, channel B, channel C,... Can be used simultaneously between the virtual wireless access points VAP in FIG. 3, two channels of channel A and channel B can be used simultaneously between the virtual wireless access points VAP. Note that the number of wireless LAN access points AP in each virtual wireless access point VAP may be any number. Further, the number of wireless LAN access points AP in each virtual wireless access point VAP does not have to be the same. For example, in FIG. 3, when the virtual wireless access point VAP3 is composed of two wireless LAN access points AP, channel A and channel B are transmitted between the virtual wireless access point VAP3 and the virtual wireless access points VAP2 and VAP4. These channels can be used simultaneously, and channels A, B, C,... Can be used simultaneously between the virtual wireless access points VAP1, VAP2.

  Next, in the wireless mesh network system 20 of the first embodiment configured as described above, the use channel in each virtual wireless access point VAP when the data transfer path from the mobile terminal 12 to the Internet 10 is set will be described. The use channel is set for the virtual wireless access point VAP of the data transfer path after setting the data transfer path when the flow is defined for the packet whose flow is undefined by the OpenFlow controller OFC. FIG. 4 is a flowchart showing a utilization channel definition method of the definition method 1. In the usage channel definition method of the definition method 1, a channel corresponding to the counter C is set as a usage channel for all virtual wireless access points VAP of the set data transfer path (step S100), and the counter C is set to a value of 1 When the counter C reaches the number of channels (step S120), the counter C is initialized to the value 1 (step S130), and the process is terminated. Channels corresponding to the counter C can be determined as, for example, channel A when the counter C = 1, channel B when the counter C = 2, channel C when the counter C = 3, and so on. Thus, every time a flow is defined, a channel different from channel A, channel B, channel C,... Is set as a use channel. The relationship between the counter C and the channel is the same in the following description.

  FIG. 5 is an explanatory diagram showing a state in which channels are allocated by the utilization channel definition method of the definition method 1 when three data transmissions are performed from the mobile terminal 12 in the configuration of FIG. In the figure, white arrows, diagonal hatched arrows, and black arrows indicate three data transmissions from the mobile terminal 12. In this example, a data transmission operation is performed from the mobile terminal 12 in the order of a white arrow, a diagonal hatched arrow, and a black arrow. In the data transmission of the white arrow, since the counter C is the initial value 1, the channel A corresponding to the counter C = 1 is set as the use channel in all the virtual wireless access points VAP1 to VAP4. In the data transmission of the next hatched hatching arrow, since the counter C is incremented by the value 1 to become the value 2, the channel B corresponding to the counter C = 2 is used by all the virtual wireless access points VAP1 to VAP4. Set as At this time, the counter C is initialized to a value 1 in order to reach the number of channels (value 2). In the data transmission of the black arrow, since the counter C has an initial value of 1, the channel A corresponding to the counter C = 1 is set as a use channel in all the virtual wireless access points VAP1 to VAP4. In this way, more even use of each channel is achieved.

  FIG. 6 is a flowchart showing a utilization channel definition method of the definition method 2. In the usage channel definition method of the definition method 2, the channel corresponding to the counter C is set as the usage channel for the first virtual wireless access point VAP in the data transfer path (step S200), and the second and subsequent virtual wireless access points A channel next to the reception channel is set as a usage channel for the VAP (step S210). That is, the channel is sequentially switched every time the virtual wireless access point VAP relays (for each hop). Then, the counter C is incremented by 1 (step S220). When the counter C reaches the number of channels (step S230), the counter C is initialized to 1 (step S240), and the process is terminated. Here, the next channel after the reception channel means the next channel in the order of channel A, channel B, channel C,. For example, as shown in FIG. 3, when each of the virtual wireless access points VAP1 to VAP4 is composed of two wireless LAN access points AP, since there are two channels A and B, the receiving channel is When the channel is A, the next channel is channel B, and when the reception channel is channel B, the next channel is channel A.

  FIG. 7 is an explanatory diagram showing a state in which channels are allocated by the utilization channel definition method of the definition method 2 when three data transmissions are performed from the mobile terminal 12 in the configuration of FIG. In the figure, white arrows, diagonal hatched arrows, and black arrows indicate three data transmissions from the mobile terminal 12. In this example, a data transmission operation is performed from the mobile terminal 12 in the order of a white arrow, a diagonal hatched arrow, and a black arrow. In the data transmission indicated by the white arrow, the counter C has an initial value of 1. Therefore, the channel A corresponding to the counter C = 1 is set as the use channel at the first virtual wireless access point VAP1. In the second virtual wireless access point VAP2, since the reception channel is channel A, channel B of the next channel is set as a use channel, and in the third virtual wireless access point VAP3, the reception channel is channel B. Channel A of the next channel is set as a usage channel, and in the fourth virtual wireless access point VAP3, since the reception channel is channel A, channel B of the next channel is set as the usage channel. That is, channel A and channel B are switched for each hop. In the data transmission of the next hatched hatching arrow, the counter C is incremented by the value 1 to become the value 2. Therefore, the channel B corresponding to the counter C = 2 at the first virtual wireless access point VAP1 is used as the use channel. In the second and subsequent virtual wireless access points VAP2 to VAP4, channel A, channel B, and channel A are set as usage channels. In the data transmission of the black arrow, since the counter C1 is the initial value 1, the channel A corresponding to the counter C = 1 is set as the use channel at the first virtual wireless access point VAP1 as in the white arrow. In the second and subsequent virtual wireless access points VAP2 to VAP4, channel B, channel A, and channel B are set as usage channels.

  FIG. 8 is a flowchart showing a utilization channel definition method of the definition method 3. In the utilization channel definition method of the definition method 3, the traffic amount within a predetermined time of each channel is acquired from each virtual wireless access point VAP (step S300), and the channel with the smallest amount of traffic within the predetermined time at each virtual wireless access point VAP is obtained. Is set as a use channel (step S310).

  FIG. 9 shows a case in which one data transmission is very large from the mobile terminal 13 to the virtual wireless access points VAP3, VAP4 and the Internet gateway IGW when one data transmission is performed from the mobile terminal 12 in the configuration of FIG. It is explanatory drawing which shows a mode that a channel is allocated with respect to the data transmission from the mobile terminal 13 by the utilization channel definition method of the definition method 3 when data transmission is performed. FIG. 10 is an explanatory diagram showing a state in which channels are allocated by the utilization channel definition method of the definition method 3 when one more data transmission is performed from the mobile terminal 12 from the state of FIG. In FIG. 9, in the data transmission of the white arrow from the mobile terminal 12, the channel A is set for all the virtual wireless access points VAP1 to VAP4. At this time, when the black arrow data transmission is performed from the mobile terminal 13 through the data transfer path of the virtual wireless access points VAP3, VAP4, and the Internet gateway IGW, in the black arrow data transmission, the use channel is the virtual wireless access point VAP3. A channel B having a small amount of traffic within a predetermined time is set for the VAP 4. From this state, when data transmission of the hatched hatched arrow is performed from the mobile terminal 12, the unused channel B is set for the virtual wireless access points VAP1 and VAP2, and the virtual wireless access points VAP3 and VAP3 are used. For VAP4, the amount of flow traffic in the data transmission indicated by the black arrow is larger than the data transmission indicated by the white arrow. Since the amount of internal traffic is small, channel A is set. In this way, more even use of each channel is achieved.

  FIG. 11 is a flowchart showing a utilization channel definition method of the definition method 4. In the utilization channel definition method of the definition method 4, the transmission traffic amount of each channel is acquired from each virtual wireless access point VAP (step S400), and sequentially within the predetermined range from the target virtual wireless access point VAP in the order of the data transfer path. The transmission traffic volume of each channel of each virtual wireless access point VAP is summed to calculate the traffic volume within the predetermined range for each channel (step S410), and the channel with the minimum traffic volume within the predetermined range is set as the use channel ( Step S420). Here, as the “predetermined range”, for example, a range (interference range) where the radio of the target virtual radio access point VAP reaches, a range of the adjacent virtual radio access point VAP, or the like can be used. In particular, the interference range is desirable. Then, it is determined whether or not there is a virtual wireless access point VAP next to the target virtual wireless access point VAP in the order of the data transfer path (step S430). When the next virtual wireless access point VAP exists, the process proceeds to step S410. Returning, when the next virtual wireless access point VAP does not exist, the process ends. That is, the processes in steps S410 and S420 are performed by sequentially changing the target virtual wireless access point VAP in the order of the data transfer path. FIG. 12 is a flowchart showing a utilization channel definition method of the definition method 4 in a case where all virtual wireless access points VAP in the data transfer path fall within a predetermined range (interference range). In this case, since all the virtual wireless access points VAP are within the predetermined range, step S410 adds the traffic amount within a predetermined time for each channel of each virtual wireless access point VAP to obtain the traffic amount within the predetermined range for each channel. The calculation process (step S410B) is performed, and the determination process in step S430 is not necessary.

  FIG. 13 is an explanatory diagram showing a state in which channels are allocated by the utilization channel definition method of the definition method 4 when another data transmission is performed from the mobile terminal 12 from the state of FIG. For ease of explanation, consider a case where all the virtual wireless access points VAP1 to VAP4 in the data transfer path fall within a predetermined range (interference range). In the state of FIG. 9, the traffic amount within the predetermined range is calculated as the sum of the transmission traffic amount (transmission flow traffic amount of data transmission indicated by white arrows) at each virtual wireless access point VAP1 to VAP4 in channel A, It is calculated as the sum of the transmission traffic volume of the wireless access points VAP3 and VAP4 (transmission flow traffic volume of data transmission indicated by black arrows). When the amount of transmission flow traffic in the black arrow data transmission is very large compared to the amount of transmission flow traffic in the white arrow data transmission, the traffic amount within the predetermined range of channel B becomes larger than that of channel A. For one data transmission from the mobile terminal 12 (data transmission with hatched hatching arrows), channel A is set as a usage channel as shown in FIG. In this way, by setting a use channel in consideration of a predetermined range (interference range), more even use of each channel can be achieved.

  Next, a description will be given of a technique for changing a flow usage channel while a plurality of data transmissions are being performed using a predefined flow. FIG. 14 is a flowchart illustrating an example of the usage channel changing method of the changing method 1. This flowchart is repeatedly executed at a constant frequency in parallel with each virtual wireless access point VAP. In the utilization channel changing method of the changing method 1, first, the traffic amount within a predetermined time and the flow traffic amount of each channel are acquired from the virtual wireless access point VAP (step S500), and the inter-channel difference of the traffic amount within the predetermined time is obtained. It is calculated (step S510), and it is determined whether or not the maximum inter-channel difference among the calculated inter-channel differences is greater than or equal to a predetermined value (step S520). Here, the “predetermined value” is used to determine whether or not it is necessary to change the use channel of the flow because the difference between channels is large, and is determined as appropriate depending on the wireless communication capacity and the predetermined time. When it is determined that the maximum inter-channel difference is equal to or greater than the predetermined value, it is determined that the use channel needs to be changed, and the maximum amount of flows transmitted in the channel with the maximum traffic volume within the predetermined time is the maximum. A flow whose flow traffic amount is closest to a value obtained by multiplying the inter-channel difference by a predetermined coefficient k1 is selected (step S530), and the use channel of the selected flow is changed to a channel that minimizes the traffic amount within a predetermined time (step S540). ). Here, the predetermined coefficient k1 is a value larger than the value 0 and smaller than the value 1, and is preferably around 0.5. The reason why the predetermined coefficient k1 is preferably in the vicinity of 0.5 is based on the fact that the difference between channels can be canceled by changing the use channel of the flow having a flow traffic amount ½ of the maximum difference between channels. On the other hand, in the virtual wireless access point VAP in which it is determined in step S520 that the maximum inter-channel difference is less than the predetermined value, it is determined that the use channel change is unnecessary, and the process is terminated without changing the use channel. .

  FIG. 15 is an explanatory diagram showing a state in which a usage channel is allocated and transmitted for two data transmissions from the mobile terminal 12 in the configuration of FIG. FIG. 16 shows how channels are allocated by the use channel definition method of the definition method 3 when data transmission is performed from the mobile terminal 13 to the Internet gateway IGW via the virtual wireless access point VAP4 from the state of FIG. It is explanatory drawing shown. FIG. 17 is an explanatory diagram showing a result when the utilization channel changing method according to the changing method 1 is executed in the state of FIG. 15 to 16, it is assumed that the data traffic of the white arrow has a smaller flow traffic volume than the data transmission of the hatched hatched arrow, and the data traffic of the black arrow is transmitted to the data transmitted by the white arrow or the hatched hatched arrow. It must be very large. In FIG. 15, in the data transmission of the white arrow from the mobile terminal 12, the channel A is set for the virtual wireless access points VAP1 to VAP4 in the data transmission of the white arrow, and in the data transmission of the hatched hatching arrow, the usage channel is Channel B is set for virtual wireless access points VAP1 to VAP4. When the black arrow data transmission is performed from the mobile terminal 13 from this state, the channel used for the black arrow data transmission is smaller in the amount of flow traffic in the data transmission in the white arrow than in the data transmission in the hatched hatching arrow. The same channel A as the data transmission channel A indicated by the white arrow is set for the virtual wireless access point VAP4. When the usage channel change method of the change method 1 is executed in the state of FIG. 16, the maximum value of the inter-channel difference is less than a predetermined value at the virtual wireless access points VAP1 to VAP3. At the virtual wireless access point VAP4, since the flow traffic volume of the black arrow data transmission is very large, the channel A flow (the white arrow data transmission and the black arrow data transmission with the maximum traffic volume within a predetermined time) is determined. ) Is obtained by multiplying the difference between channels A and B by a predetermined coefficient k1 (about 0.5) ((flow traffic amount of data transmission indicated by white arrow + flow traffic amount of data transmission indicated by black arrow−diagonal line) The flow with the closest flow traffic volume to the hatched arrow (flow traffic volume) x k2) (white arrow data) Shin) is selected, a predetermined time in traffic usage channel data transmission) in the flow (white arrow is changed to the lowest channel B. This state is shown in FIG. As shown in the figure, each channel is used more evenly.

  FIG. 18 is a flowchart illustrating an example of a usage channel change method of the change method 2. This flowchart is repeatedly executed at a constant frequency. In the utilization channel changing method of the change method 2, the transmission traffic volume and the transmission flow traffic volume of each channel are acquired from each virtual radio access point VAP (step S600), and the target virtual radio access points are sequentially applied in the order of the data transfer path. The processing from step S610 to step S680 described below is executed for the VAP.

  In the processing for each virtual wireless access point VAP, first, the transmission traffic amount in each channel of each virtual wireless access point VAP within a predetermined range from the target virtual wireless access point VAP is totaled to obtain the traffic amount within the predetermined range for each channel. The difference between the channels is calculated as a difference between the channels of the traffic amount within the predetermined range (step S610) (step S620). In the virtual wireless access point VAP with the maximum inter-channel difference, the maximum inter-channel difference is multiplied by the predetermined coefficient k2 in the flow group transmitted on the channel with the maximum amount of traffic within the predetermined range. It is confirmed whether or not it is possible to select a flow having a transmission flow traffic amount closest to the upper limit value within a predetermined coefficient range (steps S630 and S640). Here, there may be a case where there are a plurality of virtual wireless access points VAP having the maximum inter-channel difference. In this case, in the first embodiment, the data transfer paths are selected in the order. The predetermined coefficient k2 is a value larger than the value 0 and smaller than the value 1, and is preferably 0.5 or less in the vicinity of 0.5. The reason why the predetermined coefficient k2 is preferably in the vicinity of 0.5 is based on the fact that the difference between channels can be canceled by changing the use channel of the flow having a flow traffic amount ½ of the maximum difference between channels. If the flow can be selected, the usage channel of the selected flow is changed to a channel that minimizes the amount of traffic within the predetermined range at the virtual wireless access point VAP (step S650), and the flow with the changed usage channel is changed. Is subtracted from and added to the transmission traffic volume of the channel before and after the change to calculate a new transmission traffic volume (step S660), and the virtual wireless access point VAP having the maximum inter-channel difference is determined in the next step S630. In step S670, the virtual wireless access point VAP that has the maximum inter-channel difference is deleted from the target that can be selected, and the virtual wireless access point VAP that has the maximum time-channel difference is still not selected. Wireless access point VAP It is determined whether or not it exists (step S680). If there is a virtual wireless access point VAP that has not been selected, the process returns to step S610. By repeating the processes from step S610 to step S680, all virtual wireless access points VAP within a predetermined range are sequentially selected as virtual wireless access points VAP with the largest inter-channel difference in step S630, and the flow channel used When changes are possible, they are changed.

  If the processes in steps S610 to S680 are repeatedly executed for the number of virtual wireless access points VAP within the predetermined range, it is determined in step S680 that there are no virtual wireless access points VAP that are not selected within the predetermined range. It is determined whether or not there is a virtual wireless access point VAP next to the target virtual wireless access point VAP in the order of the path (step S690). When the next virtual wireless access point VAP exists, the process returns to step S610, The virtual wireless access point VAP is set as the target virtual wireless access point VAP, and the processes of steps S610 to S680 are repeatedly executed for the number of virtual wireless access points VAP within a predetermined range.

  When the processes of steps S610 to S680 are executed for all virtual wireless access points VAP in the order of the data transfer path, it is determined whether or not all the inter-channel differences are equal to or smaller than a predetermined value (step S700). It is determined whether or not the processes in steps S610 to S680 have been executed a predetermined number of times for all virtual wireless access points VAP in the order of the transfer path (step S710). When the number of times is not executed, the process returns to step S610, and the processes of steps S610 to S680 are executed again for all virtual wireless access points VAP in the order of the data transfer path. On the other hand, when all the inter-channel differences are less than or equal to a predetermined value, or when all the inter-channel differences are not less than or equal to the predetermined value, the routine is terminated. Here, for example, 5 times, 10 times, 20 times, or the like can be used as the predetermined number of times. As described above, by considering the transmission traffic amount of each channel of each virtual wireless access point VAP within a predetermined range from the virtual wireless access point VAP, it is possible to more evenly use each channel as the entire data transfer path. it can.

  FIG. 19 is a flowchart showing a utilization channel definition method of the change method 2 when all virtual wireless access points VAP in the data transfer path fall within a predetermined range (interference range). In this case, since all the virtual wireless access points VAP are within the predetermined range, step S610 calculates the amount of traffic within the predetermined range for each channel by summing the transmission traffic amount of each channel of each virtual wireless access point VAP. This is a process (step S610B), and the determination process in step S690 is not necessary.

  FIG. 20 is an explanatory diagram showing a result when the use channel is changed by the use channel change method of the change method 2 in the state of FIG. For ease of explanation, consider a case where all the virtual wireless access points VAP1 to VAP4 in the data transfer path fall within a predetermined range (interference range). In the state of FIG. 17, the traffic amount within the predetermined range is the sum of the transmission traffic amounts of the virtual wireless access points VAP1 to VAP3 (sum of the transmission flow traffic amount of data transmission indicated by white arrows) and the virtual wireless access point VAP4 in the channel A. It is calculated as the sum of the transmission traffic volume (transmission flow traffic volume for black arrow data transmission), and for channel B, the sum of the transmission traffic volume of virtual wireless access points VAP1 to VAP3 (transmission flow traffic for data transmission indicated by hatched arrows) The sum of the transmission traffic volume of the virtual wireless access point VAP4 (the sum of the transmission flow traffic volume of the data transmission indicated by the diagonally hatched arrow and the transmission flow traffic volume of the data transmission indicated by the white arrow). As described above, the transmission flow traffic volume for data transmission indicated by the black arrow is very large compared to the transmission flow traffic volume for data transmission indicated by the white arrow or the hatched hatched arrow. Becomes channel A. Since the inter-channel differences at the virtual wireless access points VAP1 to VAP4 are the same, the virtual wireless access points VAP with the maximum inter-channel difference are virtual wireless access points VAP1 to VAP4. In the first embodiment, when there are a plurality of virtual wireless access points VAP having the maximum inter-channel difference, the virtual wireless access point VAP1 is selected because it is selected in the order of the data transfer path. Transmission flow traffic closest to the upper limit within a predetermined coefficient range obtained by multiplying the maximum inter-channel difference by a predetermined coefficient k2 (k2 is preferably close to 0.5) in the channel A flow group of the virtual wireless access point VAP1. Since the amount of transmission flow traffic for the data transmission indicated by the black arrow is very large, the data transmission indicated by the white arrow is selected as the flow with the transmission flow traffic amount closest to the upper limit within the predetermined coefficient range. The channel used for the flow (data transmission with white arrows) is changed to channel B with a small amount of traffic within a predetermined range. When the channel used for data transmission indicated by the white arrow of the virtual wireless access point VAP1 is changed to channel B, the traffic amount within the predetermined range decreases by the amount of transmission flow traffic of data transmission indicated by the white arrow in channel A, and in channel B Although the amount increases accordingly, the transmission flow traffic amount of the data transmission indicated by the black arrow is dominant, and therefore the channel with the maximum traffic amount within the predetermined range is continued in channel A. Since the virtual wireless access point VAP1 is excluded from the target, the virtual wireless access point VAP2 is selected as the virtual wireless access point VAP that maximizes the inter-channel difference, and as with the virtual wireless access point VAP1, the white arrow The data transmission flow is selected and the channel used is changed to channel B with a small amount of traffic within a predetermined range. The same applies to the virtual wireless access point VAP3. Finally, the virtual wireless access point VAP4 becomes the virtual wireless access point VAP with the maximum inter-channel difference, but the flow (black arrow data transmission) is selected because the amount of transmission flow traffic of the black arrow data transmission is very large. Cannot be used, and the use channel is not changed. This state is shown in FIG.

  Next, an experiment on how much the network capacity has been increased by the wireless mesh network system 20 of the first embodiment was performed, and the result will be described. As a basic configuration in the experiment, as shown in FIG. 21 and FIG. 23, the data transfer path is divided into client computer PC1, virtual wireless access point VAP1, virtual wireless access point VAP2, virtual wireless access point VAP3, virtual wireless access point VAP4. As the client computer PC2, IEEE802.11a (100ch / 112ch) was used, and the OpenFlow controller OFC was connected to each virtual wireless access point VAP1 to VAP4 by wire.

  In Experiment 1, two data transmissions at a transmission rate of 7M were performed from the client computer PC1 by the comparative example and the utilization channel definition method of the definition method 1, and the utilization channel during data transmission was not changed. FIG. 21 is an explanatory diagram schematically showing the method of Experiment 1, and FIG. 22 is an explanatory diagram showing the result of Experiment 1. In FIG. As a comparative example, four wireless LAN access points that can use only a single channel are used instead of the four virtual wireless access points VAP1 to VAP4. As shown in FIG. 22, in the comparative example, traffic for two flows flows through one channel and thus the throughput is as small as 8.25 to 8.44. Is distributed over two channels, and the traffic flows, the throughput is as high as 14.08 to 14.10.

  In Experiment 2, when the usage channel is set by the usage channel definition method of the definition method 1 and the usage channel is not changed during data transmission (hereinafter simply referred to as “definition method 1”), the usage channel of the definition method 2 When the usage channel is set by the definition method and the usage channel is not changed during data transmission (hereinafter simply referred to as “definition method 2”), the usage channel is set by the usage channel definition method of the definition method 3, and thereafter When the usage channel is changed during data transmission by the changing method 1 using channel changing method (hereinafter simply referred to as “changing method 1”), the using channel is set using the defining method 4 using channel definition method, and thereafter When changing the usage channel during data transmission by the usage channel changing method of the changing method 2 (hereinafter referred to simply as “changing method 2”) Cormorant.) For four cases, the transmission rate 1M, and the data transmission of the transmission rate 0.1M alternately data transmission of the transmission rate 0.1M after transmitting each 12 transmits 12. FIG. 23 is an explanatory view schematically showing the method of Experiment 2, and FIG. 24 is an explanatory view showing the result of Experiment 2. As shown in FIG. 24, in the definition method 1, since the channel usage is biased, the throughput is as small as 9.31 to 10.64. In the definition method 2, since the channel usage is equalized compared to the definition method 1, the throughput is increased to 12.87 to 14.26. In the change method 1, the traffic is smoothed in each channel by dynamic channel assignment, so the throughput is as large as 14.25 to 14.27. Even in the change method 2, since the traffic is smoothed by each channel by dynamic channel assignment, the throughput is as large as 14.25 to 14.26. In Experiment 2, no significant difference could be recognized between the change method 1 and the change method 2.

  In Experiment 3, two data transmissions with a transmission rate of 3.5 M are transmitted from the client computer PC1 to the client computer PC2 via the virtual wireless access points VAP1, VAP2, VAP3, and VAP4 for the modification method 1 and the modification method 2. Thereafter, data transmission at a transmission rate of 28.5M was performed from the client computer PC3 to the client computer PC3 via the virtual wireless access points VAP3 and VAP4. FIG. 25 is an explanatory diagram schematically illustrating the technique of Experiment 3, and FIG. 26 is an explanatory diagram illustrating the result of Experiment 3. As shown in FIG. 26, in the change method 1, the transmission traffic of the virtual wireless access points VAP1 and VAP2 is affected by the large transmission traffic of the virtual wireless access point VAP3 due to the individual control of each virtual wireless access point VAP. The throughput is not so large as 26.30 to 28.03. In the change method 2, since the use channel of the transmission traffic of the virtual wireless access points VAP1 and VAP2 is also changed by the wide area control, the throughput is as large as 33.26 to 35.46.

  According to the wireless mesh network system 20 of the first embodiment described above, a plurality of virtual wireless access points VAP formed by connecting a plurality of wireless LAN access points AP in a daisy chain so as to be able to transmit and receive each other by wire are used as wireless access points. By configuring the mesh network 22, the same number of channels as the number of wireless LAN access points AP configuring the virtual wireless access point VAP can be used simultaneously. As a result, the network capacity of the wireless backbone network can be dramatically increased. In addition, since OpenFlow is used, simultaneous use of a plurality of channels for data transfer can be easily performed.

  In the wireless mesh network system 20 of the first embodiment, a different channel is set as a use channel every time a flow is defined using the use channel definition method of the definition method 1, thereby promoting more even use of each channel. be able to. In addition, by using the usage channel definition method of the definition method 2 and setting a different channel as the usage channel every time it hops in the data transfer path, each channel is compared with the case of the usage channel definition method of the definition method 1. Further equal use can be promoted.

  In the wireless mesh network system 20 of the first embodiment, by using the usage channel definition method of the definition method 3, the flow having the minimum traffic amount within a predetermined time is set as the usage channel for each virtual radio access point VAP. By defining, it is possible to promote more even use of each channel compared to the case of using the definition channel 1 using channel definition method and the definition method 2 using channel definition method.

  In the wireless mesh network system 20 of the first embodiment, by using the utilization channel definition method of the definition method 4, the traffic amount within a predetermined time of the virtual wireless access point belonging to the predetermined range is determined for each channel for each virtual wireless access point VAP. To calculate the traffic volume within a predetermined range for each channel, and by defining the channel having the minimum traffic volume within the predetermined range as the usage channel in the flow, the virtual wireless access points VAP within the predetermined range Considering the transmission / reception state, it is possible to promote further equal use of each channel.

  In the wireless mesh network system 20 of the first embodiment, by using the usage channel change method of the change method 1, the flow group is transmitted to each virtual wireless access point VAP through the channel having the maximum traffic volume within a predetermined time. By selecting one flow and changing the usage channel so that the selected flow is transmitted on the channel with the smallest amount of traffic within the predetermined time, the traffic amount within the predetermined time of the channel changes over time. Even so, more even use of each channel can be promoted. As a result, the network capacity of the wireless backbone network can be further increased. In addition, an inter-channel difference is calculated as a difference in traffic amount within a predetermined time between channels, and the flow traffic amount closest to a value obtained by multiplying the maximum inter-channel difference among the calculated inter-channel differences by a predetermined coefficient k1 is obtained. Since the flow is selected, it is possible to more efficiently use each channel more efficiently by adjusting the predetermined coefficient. In addition, when the maximum inter-channel difference among the inter-channel differences is less than a predetermined value, the use channel is not changed, so that unnecessary change of the use channel can be suppressed.

  In the wireless mesh network system 20 according to the first embodiment, the transmission traffic of each channel of each virtual wireless access point VAP belonging to a predetermined range is transmitted to each virtual wireless access point VAP using the usage channel changing method of the change method 2. The amount of traffic within a predetermined range for each channel is calculated by summing the amounts, and the inter-channel difference as a difference between channels of the traffic amount within the predetermined range is calculated, and the channels of the virtual wireless access points VAP belonging to the predetermined range are calculated. For the virtual wireless access point VAP with the largest difference between the channels, one flow is selected from the flow group transmitted through the channel with the maximum traffic volume within the predetermined range, and the selected flow is the traffic volume within the predetermined range. Is used so that is transmitted on the smallest channel. By changing the Le, also vary the predetermined time in the amount of traffic channels with the lapse of time, it is possible to achieve a more uniform utilization of each channel in the data transfer as a whole the data transfer path. In addition, when there is a flow having a transmission flow traffic amount within a predetermined coefficient range obtained by multiplying the maximum inter-channel difference among the inter-channel differences by the predetermined coefficient k2, the transmission flow traffic amount is the highest in the upper limit value of the predetermined coefficient range. By changing the usage channel by selecting a close flow, and changing the usage channel when there is no flow with the flow traffic amount within the predetermined coefficient range, it is possible to suppress unnecessary changes in the usage channel. . Further, in the virtual wireless access point VAP where the inter-channel difference is maximized, when the use channel is changed, the flow traffic amount of the flow related to the change is subtracted from the transmission traffic amount of the channel before the change and the transmission traffic of the channel after the change is made The virtual wireless access point VAP that is the target of the virtual wireless access point VAP that maximizes the difference between channels is deleted from the target of the virtual wireless access point VAP that maximizes the difference between channels in step S630, Since the processes in steps S610 to S680 are repeated until there is no virtual wireless access point VAP as a selection target in step S630, channel usage within a predetermined range can be equalized with high accuracy. In addition, the first virtual wireless access in the order of the data transfer path until the processing in steps S610 to S680 is executed a predetermined number of times even if all the inter-channel differences are less than or equal to the predetermined value or less than the predetermined value. Since the processing in steps S610 to S680 is repeated with the point VAP as the target virtual wireless access point VAP, equalization of channel usage over the entire data transfer path can be performed with high accuracy.

  In the wireless mesh network system 20 of the first embodiment, it is assumed that it is connected to the Internet 10 by a plurality of Internet gateways IGW, but it may not be connected to the Internet.

  In the wireless mesh network system 20 of the first embodiment, each virtual wireless access point VAP is connected in a daisy chain so that a plurality of wireless LAN access points AP can be transmitted to and received from each other by wire. The point APs are connected in a daisy chain so that they can be transmitted and received with each other wirelessly, or some of the plurality of wireless LAN access points AP are connected in a wired manner and the rest are connected in a daisy chain so that they can be transmitted and received with each other wirelessly. It may be a thing.

  In the wireless mesh network system 20 of the first embodiment, OpenFlow is used. However, it is not always necessary to use OpenFlow.

  In the wireless mesh network system 20 of the first embodiment, the definition of the usage channel definition method of the definition method 1, the usage channel definition method of the definition method 2, and the usage channel definition method of the definition method 3 Although the use channel of each virtual wireless access point VAP is set, the use channel of each virtual wireless access point VAP in the data transfer path is defined at the time of flow definition using a definition method other than these use channel definition methods. It may be set.

  In the wireless mesh network system 20 of the first embodiment, in the usage channel changing method of the changing method 1, the traffic volume of the virtual wireless access point VAP is the largest among the flow groups transmitted on the channel with the maximum amount of time. The flow having the closest flow traffic amount to the value obtained by multiplying the inter-channel difference by the predetermined coefficient k1 is selected. However, the flow having the smallest flow traffic amount is selected as the flow for changing the use channel, or the flow traffic is selected. An arbitrary flow other than the flow with the maximum amount may be selected as a flow for changing the use channel.

  In the wireless mesh network system 20 of the first embodiment, in the usage channel change method of the change method 1, when the maximum inter-channel difference among the inter-channel differences in the traffic amount within a predetermined time is less than a predetermined value, the usage channel is changed. Although not performed, it is possible to always change the use channel regardless of the maximum inter-channel difference value.

  In the wireless mesh network system 20 of the first embodiment, in the utilization channel changing method of the change method 2, the virtual wireless access point VAP having the maximum inter-channel difference has the maximum traffic volume within the predetermined range from the flow group of the channel. The flow having the flow traffic amount closest to the upper limit value within the predetermined coefficient range obtained by multiplying the difference between channels by the predetermined coefficient k2 is selected as the flow for changing the use channel. May be selected as a flow for changing the usage channel, or any flow other than the flow with the largest flow traffic volume may be selected as the flow for changing the usage channel.

  In the wireless mesh network system 20 of the first embodiment, in the use channel change method of the change method 2, the flow traffic amount of the changed flow is changed when the use channel is changed in the virtual wireless access point VAP in which the inter-channel difference is maximum. The virtual wireless access point VAP that is the target of the virtual wireless access point VAP that is subtracted from the traffic amount within a predetermined time period of the channel before the change and is added to the traffic amount within the predetermined time period of the channel after the change to maximize the inter-channel difference Are deleted from the target of the virtual wireless access point as the selection target in step S630, and the processes in steps S610 to S680 are repeated until there is no virtual wireless access point VAP as the selection target in step S630. But Such a repetition may be as not done.

  In the wireless mesh network system 20 of the first embodiment, in the utilization channel changing method of the change method 2, steps S610 to S610 are performed until there is no virtual wireless access point VAP next to the target virtual wireless access point VAP in the order of the data transfer path. Although the process of S680 is repeatedly performed, such repetition may not be performed.

  In the wireless mesh network system 20 of the first embodiment, in the usage channel changing method of the change method 2, even if all the inter-channel differences are less than a predetermined value or all the inter-channel differences are not less than the predetermined value. The processing in steps S610 to S690 is repeated until the predetermined number of times is executed. However, regardless of the number of repetitions, the processing is repeatedly performed until all the inter-channel differences are equal to or less than the predetermined value. Regardless of the value, the process may be repeatedly executed up to a predetermined number of times. In addition, such repeated processing may not be performed.

  Next, the wireless mesh network system 120 according to the second embodiment of the present invention will be described. The wireless mesh network system 120 of the second embodiment has the same configuration as the wireless mesh network system 20 of the first embodiment. Therefore, in order to avoid redundant description, the same reference numerals are given to the same configurations as those of the wireless mesh network system 20 of the first embodiment among the configurations of the wireless mesh network system 120 of the second embodiment. Description is omitted.

  In the wireless mesh network system 120 of the second embodiment, the channels are classified into group A and group B. As the initial value of group discrimination, the channel with the lowest transmission rate is set as group B, and the other channels are set as group A. Then, a usage channel is assigned to one of the channels of group A to the new flow by the usage channel definition method of definition method 5, and a new flow in which the usage channel is assigned to the channel of group A by the usage channel change method of change method 3 Change to group B channel. FIG. 27 is a flowchart illustrating an example of the usage channel definition method of the definition method 5, and FIG. 28 is a flowchart illustrating an example of the usage channel change method of the change method 3.

  In the usage channel definition method of the definition method 5, first, it is determined whether or not the calculation required time has elapsed since the usage channel was defined for the previous new flow (step S1100). Here, the calculation required time is set in advance as a time required until the transfer rate of the new flow can be calculated after the use channel is assigned to the new flow. Note that the usage channel changing method of FIG. 28 is executed when the required calculation time has elapsed since the usage channel was defined for the new flow. When the calculation required time has elapsed since the use channel was defined for the previous new flow, the channel having the highest transmission rate among the channels of group A is defined as the use channel for the new flow (step S1110). ) When the calculation required time has not elapsed since the use channel was defined for the previous new flow, the value 1 is set to the number of flows flowing through the transmission rate of the group A channels for the new flow. A channel having the maximum expected value obtained by dividing by the added number (the number of flows + 1) is defined as a use channel (step S1120). The expected value means a rate that can be expected per flow of the channel. For example, the expected value is a transmission rate in a channel in which data is not transmitted and received, a transmission rate / 2 in a channel in which one flow is flowing, and a transmission rate / 3 in a channel in which two flows are flowing. It becomes.

  In the utilization channel changing method of the changing method 3, first, the number of transmission packets for each channel and the number of bytes of each transmission packet within the calculation required time are obtained from each virtual wireless access point VAP (step S1200). Subsequently, the channel occupation time and the remaining time of each flow within a predetermined time in each channel are calculated from the transmission rate of each channel of group B, the number of transmitted packets, and the number of bytes of each transmitted packet (step S1210). Here, the channel occupation time is obtained by multiplying the ratio of the transfer rate of the flow flowing in the channel to the transmission rate of the channel (the channel occupation rate of the flow) and a predetermined time. The remaining time is obtained by subtracting the sum of the channel occupation times of the respective flows of the channel from the predetermined time. The ratio of the remaining time to the predetermined time is referred to as a channel non-use rate, and the value obtained by subtracting the channel non-use rate from the value 1 is referred to as a channel use rate.

  Next, for the target flow of group A (a new flow for which a calculation required time has elapsed after the use channel is defined), the number of transmission packets within a predetermined time, the number of bytes of each transmission packet, and the transmission rate of each channel of group B Then, the channel occupation time for each channel of group B within a predetermined time is calculated (step S1220). That is, the channel occupation time when the target flow is made to flow through each channel of loop B is calculated. Then, the remaining time after the change when the target flow of group A is changed to each channel of group B is calculated, and the channel having the minimum remaining time of 0 or more is changed as the use channel of the target flow ( Step S1230). Here, the minimum remaining time means that the channel non-use rate is minimum, in other words, the channel usage rate is maximum. If the remaining time after the change is negative, it means that the channel utilization rate exceeds 100%, which means that packet loss occurs when the target flow is transmitted and received on that channel. In the method 3 for changing the use channel, the use channel cannot be changed to that channel. When the target flow usage channel cannot be changed to the group B channel, the target flow usage channel (group A channel) is changed to group B (steps S1240 and S1250).

  When either the use channel is changed or the use channel is changed to group B, it is determined whether or not there is a channel in which transmission / reception is completed and no flow is flowing among the channels of group B (step S1260) When there is a channel that does not flow, the channel is changed to group A (step S1270). In this case, if there is only one group B channel and the channel is changed to group A, the channel of group B disappears, so the channel with the lowest transmission rate is immediately assigned to group B as the initial value. It will be distinguished.

  FIG. 29 is a diagram illustrating a state in which channels are allocated by the definition channel 5 using channel definition method when 3 Mbps data is transmitted from the mobile terminal 12a to the mobile terminal 12b via the virtual wireless access points VAP1 to VAP4. FIG. In FIG. 29, the transmission rates of channels A to D are 9 Mbps, 54 Mbps, 9 Mbps, and 54 Mbps in order, and channel C with the lowest transmission rate is distinguished as group B as an initial value, and channels A, B, and D are grouped. A is distinguished. As data transmission conditions, 1.8 Mbps data can be stably transmitted and received in a channel with a transmission rate of 9 Mbps, and 9 Mbps data can be stably transmitted and received in a channel with a transmission rate of 54 Mbps. Therefore, if only transmission or reception is performed, it is possible to stably transmit or receive data of 3.6 Mbps on a channel with a transmission rate of 9 Mbps, and stably transmit or receive data of 18 Mbps on a channel with a transmission rate of 54 Mbps. become. This means that a header such as a source IP address, a destination IP address, a transmission port number, a reception port number, a waiting time, and the like are added to the transmission packet, so that the transmission rate is 1.8 Mbps for a channel of 9 Mbps. This means that the channel utilization rate becomes 100% due to transmission / reception of a channel, and the channel utilization rate becomes 100% due to transmission / reception at 9 Mbps in a channel with a transmission rate of 54 Mbps. Also, consider a case where all virtual wireless access points VAP in the data transfer path fall within the interference range. In the utilization channel definition method of the definition method 5, since the new flow (white arrow) is assigned to the channel with the maximum transmission rate among the channels of group A, it is assigned to either channel A or D as shown in the figure. It will be. In FIG. 29, it is assigned to channel D.

  FIG. 30 is an explanatory diagram showing how the usage channel is changed by the usage channel changing method of the change method 3 with respect to the state of FIG. In the first hop (transmission / reception between the virtual wireless access points VAP1 and VAP2), the channel of group B is only channel C, the virtual wireless access point VAP1 is only transmitting, and the virtual wireless access point VAP2 is only receiving. , 3 Mbps data can be stably transmitted and received on channel C. That is, the remaining time is 0 or more. For this reason, the use channel is changed to the channel C of the group B. The channel utilization rate in this case can be calculated as (3 Mbps / 3.6 Mbps). In the second hop (transmission / reception between the virtual wireless access points VAP2 to VAP3), all the virtual wireless access points VAP in the data transfer path are in the interference range in the channel C of the group B whose usage channel is changed in the first hop. When the usage channel is changed to channel C, the channel usage rate exceeds 100% and the remaining time becomes a negative value. For this reason, the use channel of the new flow is not changed, and the channel D of the group A is changed to the group B.

  FIG. 31 shows a case where 3 Mbps data transmission (diagonal hatched arrow) is performed as a new flow from the mobile terminal 12a to the mobile terminal 12b via the virtual wireless access points VAP1 to VAP4 in the state of FIG. It is explanatory drawing which shows a mode that a channel is allocated with respect to a new flow by the utilization channel definition method of the definition method 5. The new flow (diagonal hatched arrow) is assigned to channel B having the higher transmission rate among channels A and B of group A. FIG. 32 is an explanatory diagram showing how the usage channel is changed by the usage channel changing method of the change method 3 with respect to the state of FIG. At the first hop (transmission / reception between the virtual wireless access points VAP1 and VAP2), all virtual wireless access points VAP in the data transfer path are in the interference range, so the use channel is not changed to the channel C of the group B. . On the other hand, even if the usage channel of the new flow (diagonal hatched arrow) is changed to the channel D of the group B, the changed channel usage rate is 6 Mbps / 9 Mbps, and the remaining time is 0 or more. For this reason, the use channel of the new flow (diagonal hatched arrow) is changed to channel D. Similarly to the first hop, the usage channel is changed to the channel D at 2 hops (transmission / reception between the virtual wireless access points VAP2 to VAP3) and the third hop (transmission / reception between the virtual wireless access points VAP3 to VAP4).

  FIG. 33 is new when 3 Mbps data transmission (black arrow) is performed as a new flow from the mobile terminal 12a to the mobile terminal 12b via the virtual wireless access points VAP1 to VAP4 in the state of FIG. It is explanatory drawing which shows a mode that a channel is allocated with the utilization channel definition method of the definition method 5 with respect to a flow. The new flow (black arrow) is assigned to channel B having the higher transmission rate among channels A and B of group A. FIG. 34 is an explanatory diagram showing how the usage channel is changed by the usage channel changing method of the change method 3 with respect to the state of FIG. Similarly to the case of FIG. 32, at the first hop (transmission and reception between the virtual wireless access points VAP1 and VAP2), the change of the use channel to the group C of the channel B is not performed. On the other hand, when the use channel of the new flow (diagonal hatched arrow) is changed to the channel D of the group B, considering the fact that all virtual wireless access points VAP in the data transfer path are in the interference range, the changed channel use The rate is 9 Mbps / 9 Mbps and the remaining time is the value 0. For this reason, the use channel of the new flow (black arrow) is changed to channel D. Similarly to the first hop, the usage channel is changed to the channel D at 2 hops (transmission / reception between the virtual wireless access points VAP2 to VAP3) and the third hop (transmission / reception between the virtual wireless access points VAP3 to VAP4).

  FIG. 35 shows a new flow of 3 Mbps black arrows before the calculation time has elapsed after assigning a channel using the definition method 5 channel definition method to define a new flow of 3 Mbps diagonal hatched arrows. It is explanatory drawing which shows a mode that a channel is allocated by the utilization channel definition method of the system 5. FIG. In this case, since the expected values of the channels A and B of the group A are 9 Mbps and 27 Mbps, the new flow indicated by the black arrow is assigned to the channel B. The change of the channel used for the group B channel of the new flow indicated by the hatched hatching arrow and the change of the channel used for the group B channel of the new flow indicated by the black arrow are the same as in the states of FIGS.

  Next, an experiment 4 was performed on how much the packet loss is reduced by the wireless mesh network system 120 of the second embodiment, and the result will be described. As a basic configuration in Experiment 4, as shown in FIG. 29 to FIG. 35, the data transfer path includes a mobile terminal 12a, a virtual wireless access point VAP1, a virtual wireless access point VAP2, a virtual wireless access point VAP3, and a virtual wireless access point VAP4. , The mobile terminal 12b, the transmission rates of channels A to D are set to 9 Mbps, 54 Mbps, 9 Mbps, and 54 Mbps in order, and IEEE802.11a (100ch / 112ch) is used. Connected by wire.

  In Experiment 4, when a plurality of flows are sequentially transmitted from the mobile terminal 12a, the usage channel definition method of the definition method 4 and the usage channel change method of the change method 2 are used (good method of the first embodiment) and the definition method. The packet loss rate and the number of packet losses when the usage channel definition method of 5 and the usage channel change method of the change method 3 were used (second embodiment) were tabulated. FIG. 36 shows the total result. As shown in FIG. 36, in the good method of the first embodiment, the minimum value of the packet loss rate is 13.825, the median value is 16.548, the maximum value is 22.695, and the minimum value of the number of packet losses is 5967. The median was 7142 and the maximum was 9795. On the other hand, in the second embodiment, the minimum value of the packet loss rate is 0.013902, the median is 0.31974, the maximum is 0.81094, the minimum value of the number of packet losses is 6, the median is 138, the maximum The value was 321. Thus, in the second embodiment, the packet loss rate and the number of packet losses can be drastically reduced even with the good method of the first embodiment.

  Similarly to the wireless mesh network system 20 of the first embodiment, the wireless mesh network system 120 of the second embodiment described above also includes a plurality of wireless LAN access points AP connected in a daisy chain so that they can be transmitted and received with each other by wire. By configuring the wireless mesh network 22 using the virtual wireless access point VAP as an access point, the same number of channels as the number of wireless LAN access points AP constituting the virtual wireless access point VAP can be used simultaneously. As a result, the network capacity of the wireless backbone network can be dramatically increased. In addition, since OpenFlow is used, simultaneous use of a plurality of channels for data transfer can be easily performed.

  In the wireless mesh network system 120 according to the second embodiment, the channel of group A is used for a new flow after the calculation required time has elapsed after the usage channel is assigned to the new flow by using the usage channel definition method of the definition method 5. By defining the channel having the maximum transmission rate among these as the use channel, a more appropriate use channel can be assigned to a new flow whose transfer rate is unknown.

  In the wireless mesh network system 120 according to the second embodiment, using the usage channel definition method of the definition method 5, for a new flow before the calculation required time elapses after the usage channel is allocated to the new flow, the group A By defining the channel that maximizes the expected value obtained by dividing the number of flows that flow through the transmission rate by the number of values 1 among the channels, it is possible to deal with new flows with unknown transfer rates. Therefore, a more appropriate usage channel can be allocated.

  In the wireless mesh network system 120 of the second embodiment, the channel having the lowest transmission rate is distinguished as the group B as the initial value, and the remaining channels are distinguished as the group A. As a result, the channel with the maximum transmission rate can be group A and the channel with the minimum transmission rate can be group B.

  In the wireless mesh network system 120 according to the second embodiment, the use channel is defined in the channel of group A when the calculation required time elapses after the use channel is assigned to the new flow by using the use channel change method of the change method 3. When the channel is changed to each channel of group B for the new flow (target flow), the remaining time after the change is calculated, and the channel in which the remaining time becomes the smallest positive value, that is, the channel utilization rate is The channel used for the target flow is changed to the maximum channel at 100% or less. As a result, the flows can be sequentially aggregated into some of the channels of the group B without causing packet loss.

  In the wireless mesh network system 120 according to the second embodiment, when the usage channel cannot be changed to the group B channel with respect to the new flow in which the usage channel is defined as the group A channel, the usage channel of the new flow is changed to the group B. The channel that is not transmitted / received among the channels of group B is changed to group A. Thereby, the group B can be distinguished and the channel of the group A can be secured as necessary.

  In the wireless mesh network system 120 according to the second embodiment, the channels of the virtual wireless access point VAP are classified into groups A and B, and the channel with the maximum transmission rate and the expected value of the channels of group A for the new flow. The largest channel is defined as the usage channel, and the new flow to which the usage channel is assigned is changed to group B after the calculation required time. However, without distinguishing the channels of the virtual wireless access point VAP into groups A and B, the channel having the maximum transmission rate or the channel having the maximum expected value is defined as the usage channel in the new flow, and the usage channel is determined after the calculation required time. The use channel may be changed for the assigned new flow. In this case, the definition method 6 utilization channel definition method illustrated in FIG. 37 and the modification method 4 utilization channel change method illustrated in FIG. 38 may be executed.

  In the usage channel definition method of the definition method 6, first, it is determined whether or not the calculation required time has elapsed since the usage channel was defined for the previous new flow (step S1300). The calculation required time is set in advance as the time until the transfer rate of the new flow is known after the usage channel is assigned to the new flow, or a time slightly longer than this time, as in the usage channel definition method of the definition method 5. Is. Therefore, the utilization channel changing method of FIG. 38 is executed when the calculation necessary time has elapsed after the utilization channel is defined for the new flow. When the calculation required time has elapsed since the channel used was defined for the previous new flow, the remaining rate of each channel is calculated from the transmission rate of each channel, the number of transmitted packets, and the number of bytes of transmitted packets (step S1310) For the new flow, the channel having the maximum residual rate is defined as the use channel (step S1320). Here, the remaining rate is obtained by subtracting the sum of the transfer rates of each flow that is being transmitted / received at that time on the target channel from the transmission rate, and is the amount of margin that can be transmitted / received without causing packet loss on the target channel. Rate. Therefore, the transmission rate is the residual rate in a channel that does not transmit or receive data. Note that the residual rate can also be indicated by “residual rate = transmission rate × residual time / predetermined time” if the above-described residual time is used. On the other hand, when the calculation required time has not elapsed since the usage channel was defined for the previous new flow, the value obtained by adding the value 1 to the number of flows flowing through the transmission rate for the new flow (number of flows The channel having the maximum expected value obtained by dividing by +1) is defined as the use channel (step S1120).

  In the utilization channel changing method of the changing method 4, first, the number of transmission packets for each channel and the number of bytes of each transmission packet within a predetermined time are acquired from each virtual wireless access point VAP (step S1400). Subsequently, the channel occupation time and the remaining time of each flow within a predetermined time in each channel are calculated from the transmission rate of each channel, the number of transmitted packets, and the number of bytes of each transmitted packet (step S1410). Next, the remaining time after the change when the use channel of the new flow (new flow for which the calculation required time has elapsed after the use channel is defined) is changed is calculated, and the remaining time is the channel whose value is 0 or more and becomes the minimum Is changed as a use channel of the new flow (step S1420). As described above, minimizing the remaining time means maximizing the channel utilization rate. When all the remaining time after the change is a negative value, the use channel is not changed.

  The usage channel of the new flow (white arrow) by the usage channel definition method of the definition method 6 is assigned to the channel with the maximum transmission rate. As in the case of the wireless mesh network system 120 according to the second embodiment described with reference to FIGS. 29 to 36, the case where the transmission rates of the channels A to D are 9 Mbps, 54 Mbps, 9 Mbps, and 54 Mbps in order is as follows. Assigned to either channel B or D. Now, considering the case where a new flow is assigned to channel D, the state is the same as in FIG. FIG. 39 is an explanatory diagram showing how the usage channel is changed by the usage channel changing method of the change method 4 with respect to the state of FIG. In the first hop (transmission / reception between virtual wireless access points VAP1 and VAP2), the remaining time after the change is minimum when the values of channels A and C are 0 or more, so the used channel is changed to one of channels A and C. The FIG. 39 shows a state where the use channel is changed to channel C. In the second hop (transmission / reception between virtual wireless access points VAP2 to VAP3), considering that all virtual wireless access points VAP in the data transfer path are in the interference range, the remaining time of channel C after the change is a negative value Thus, the remaining time of channel A is minimum when the value is 0 or more. Therefore, the usage channel is changed to channel A. In the third hop (transmission / reception between the virtual wireless access points VAP3 to VAP4), the remaining times of the channels A and C after the change are both negative values, and the remaining times of the channels B and D are minimum when the value is 0 or more. . For this reason, the utilization channel is held in channel D.

  FIG. 40 shows a state in which 3 Mbps data transmission (diagonal hatched arrow) is performed as a new flow from the mobile terminal 12a to the mobile terminal 12b via the virtual wireless access points VAP1 to VAP4 in the state of FIG. It is explanatory drawing which shows a mode that a channel is allocated with respect to a new flow by the utilization channel definition method of the definition method 6. FIG. A new flow (diagonal hatched arrow) is assigned to channel B having the maximum transmission rate. FIG. 41 is an explanatory diagram showing how the usage channel is changed by the usage channel changing method of the change method 4 with respect to the state of FIG. In the first hop (transmission / reception between the virtual wireless access points VAP1 and VAP2), the change to the changed channels A and C is not performed. In channel D, 3 Mbps white arrow data is transmitted / received at the third hop (transmission / reception between virtual wireless access points VAP3 to VAP4). Therefore, considering this influence, the channel utilization rate after change is 6 Mbps / 9 Mbps, and the remaining time is minimum when the value is 0 or more. For this reason, the utilization channel is changed to channel D. The second hop (transmission / reception between the virtual wireless access points VAP2 to VAP3) and the third hop (transmission / reception between the virtual wireless access points VAP3 to VAP4) are also changed to the channel D in the same manner as the first hop.

  FIG. 42 is new when 3 Mbps data transmission (black arrow) is performed as a new flow from the mobile terminal 12a to the mobile terminal 12b via the virtual wireless access points VAP1 to VAP4 in the state of FIG. It is explanatory drawing which shows a mode that a channel is allocated with the utilization channel definition method of the definition method 6 with respect to a flow. The new flow (black arrow) is assigned to channel B with the maximum transmission rate. FIG. 43 is an explanatory diagram showing how the usage channel is changed by the usage channel changing method of the change method 4 with respect to the state of FIG. In the first hop (transmission / reception between the virtual wireless access points VAP1 and VAP2), the change to the changed channels A and C is not performed. Channel D performs transmission / reception of 3 Mbps white arrow data and 3 Mbps diagonal hatched arrow data in the third hop (transmission / reception between virtual wireless access points VAP3 to VAP4). Considering this, the channel utilization after the change is 9 Mbps / 9 Mbps, and the remaining time is 0. For this reason, the utilization channel is changed to channel D. The second hop (transmission / reception between the virtual wireless access points VAP2 to VAP3) and the third hop (transmission / reception between the virtual wireless access points VAP3 to VAP4) are also changed to the channel D in the same manner as the first hop.

  Thus, without distinguishing the channels of the virtual wireless access point VAP into groups A and B, the channel with the maximum transmission rate or the channel with the maximum expected value is used for the new flow by the usage channel definition method of the definition method 6. Even if the channel used for the new flow to which the channel used is allocated after the calculation required time is changed to the channel whose remaining time after the change is 0 or more and becomes the minimum by the channel change method of the change method 4 Effects similar to those of the wireless mesh network system 120 of the second embodiment, for example, the effect of being able to use the same number of channels as the number of wireless LAN access points AP constituting the virtual wireless access point VAP, the network of the wireless backbone network Capacity can be increased dramatically As a result, the use of OpenFlow can facilitate the simultaneous use of multiple channels for data transfer, the effect of assigning more appropriate channels to new flows with unknown transfer rates, and packet loss. It is possible to obtain an effect that the usage channels of the flow can be sequentially aggregated into some channels without being generated.

  In the wireless mesh network system 20 of the first embodiment and the wireless mesh network system 120 of the second embodiment described above, a plurality of wireless LAN access points AP are connected in a daisy chain so that they can be transmitted and received with each other by wire. The virtual wireless access point VAP is configured as an access point that can simultaneously use the same number of channels as the number of wireless LAN access points AP. However, since the virtual wireless access point VAP only needs to be an access point that can simultaneously use a plurality of channels, a part of the virtual mesh network system 20 of the first embodiment and the virtual mesh network system 120 of the second embodiment are partially virtual. The wireless access point VAP may be configured by a single wireless access point AP that can simultaneously use a plurality of channels, or all of the wireless mesh network system 20 of the first embodiment and the wireless mesh network system 120 of the second embodiment. The virtual wireless access point VAP may be configured by a single wireless access point AP that can simultaneously use a plurality of channels. Even if a part or all of the virtual wireless access point VAP is configured by a single wireless access point AP that can simultaneously use a plurality of channels, the wireless mesh network system 20 of the first embodiment and the wireless mesh network of the second embodiment The same effect as that of the system 120 can be obtained. Further, a part of the wireless access point AP constituting the virtual wireless access point VAP may be configured by a single wireless access point AP that can be used simultaneously by a plurality of channels.

  In the wireless mesh network system 20 of the first embodiment and the wireless mesh network system 120 of the second embodiment, OpenFlow is used. However, SDN (software defined network) as a generalized concept of OpenFlow may be used. In this case, the “open flow switch function” is referred to as a “data plane function”, and the “open flow controller function” is referred to as a “control plane function”.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of wireless mesh network systems.

  10 Internet, 12, 12a, 12b, 13 Mobile terminal, 20, 120 Wireless mesh network system, 22 Wireless mesh network, AP Wireless LAN access point, IGW Internet gateway, OFC open flow controller, PC1 to PC3 Client computer, VAP, VAP1 ~ VAP4 Virtual wireless access point.

Claims (21)

A wireless mesh network system,
By connecting multiple wireless access points in a daisy chain by wire or wireless, it is possible to use the same number of channels as the number of wireless access points at the same time, and it has an open flow switch function and functions as an access point for a wireless mesh network. A virtual wireless access point;
A control apparatus for setting a data transfer path in a wireless mesh network and a use channel used for data transfer among the same number of channels of the virtual wireless access points included in the data transfer path by an open flow controller function; ,
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The virtual wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow. Yes,
Furthermore,
Each time the control device defines a flow, the use channel is defined in the flow so that the channels are sequentially transmitted through different channels among the available channels.
Wireless mesh network system. The wireless mesh network system according to claim 1,
The control device defines the usage channel as a flow to be transmitted on the same channel in the data transfer path,
Wireless mesh network system. The wireless mesh network system according to claim 1,
The control device defines the usage channel as a flow so that it is transmitted on a different channel every time it hops in the data transfer path.
Wireless mesh network system. A wireless mesh network system,
By connecting multiple wireless access points in a daisy chain by wire or wireless, it is possible to use the same number of channels as the number of wireless access points at the same time, and it has an open flow switch function and functions as an access point for a wireless mesh network. A virtual wireless access point;
A control apparatus for setting a data transfer path in a wireless mesh network and a use channel used for data transfer among the same number of channels of the virtual wireless access points included in the data transfer path by an open flow controller function; ,
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The virtual wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow. Yes,
Furthermore,
The virtual wireless access point aggregates and holds the traffic amount within a predetermined time as the traffic amount transmitted / received within a predetermined time in each channel,
The control device acquires the traffic amount within the predetermined time for each virtual wireless access point, and defines a flow with the channel having the minimum traffic amount within the predetermined time as the use channel.
Wireless mesh network system. A wireless mesh network system,
By connecting multiple wireless access points in a daisy chain by wire or wireless, it is possible to use the same number of channels as the number of wireless access points at the same time, and it has an open flow switch function and functions as an access point for a wireless mesh network. A virtual wireless access point;
A control apparatus for setting a data transfer path in a wireless mesh network and a use channel used for data transfer among the same number of channels of the virtual wireless access points included in the data transfer path by an open flow controller function; ,
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The virtual wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow. Yes,
Furthermore,
The virtual wireless access point aggregates and holds the traffic amount within a predetermined time as the traffic amount transmitted / received within a predetermined time in each channel,
The control device acquires the traffic volume within a predetermined time period for each virtual wireless access point, and sums the traffic volume within a predetermined time period for virtual wireless access points belonging to a predetermined range for each channel. Calculating a traffic amount within a predetermined range and defining a channel in which the traffic amount within a predetermined range is minimum as the use channel in the flow;
Wireless mesh network system. A wireless mesh network system,
By connecting multiple wireless access points in a daisy chain by wire or wireless, it is possible to use the same number of channels as the number of wireless access points at the same time, and it has an open flow switch function and functions as an access point for a wireless mesh network. A virtual wireless access point;
A control apparatus for setting a data transfer path in a wireless mesh network and a use channel used for data transfer among the same number of channels of the virtual wireless access points included in the data transfer path by an open flow controller function; ,
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The virtual wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow. Yes,
Furthermore,
The virtual wireless access point aggregates and holds the traffic amount within a predetermined time as the traffic amount transmitted / received within a predetermined time in each channel,
The control device, for each virtual wireless access point,
(A1) Obtain the traffic amount within the predetermined time from the virtual wireless access point;
(B1) A usage channel is selected so that one flow is selected from the flow group transmitted on the channel with the maximum amount of traffic within the predetermined time, and the selected flow is transmitted with the channel with the minimum amount of traffic within the predetermined time. Change
Wireless mesh network system. The wireless mesh network system according to claim 6,
The virtual wireless access point aggregates and holds the flow traffic volume as the traffic volume for each flow transmitted and received within the predetermined time in each channel,
The control device includes:
In (A1), the flow traffic volume is acquired together with the traffic volume within the predetermined time,
In (B1), the flow traffic closest to the value obtained by calculating the inter-channel difference as a difference in traffic volume within a predetermined time between channels and multiplying the maximum inter-channel difference by the predetermined coefficient among the calculated inter-channel differences. Select the flow that will be the quantity as the one flow,
Wireless mesh network system. The wireless mesh network system according to claim 6 or 7,
In (B1), when the maximum inter-channel difference among the calculated inter-channel differences is less than a predetermined value, the control device does not change the use channel of the selected flow.
Wireless mesh network system. A wireless mesh network system,
By connecting multiple wireless access points in a daisy chain by wire or wireless, it is possible to use the same number of channels as the number of wireless access points at the same time, and it has an open flow switch function and functions as an access point for a wireless mesh network. A virtual wireless access point;
A control apparatus for setting a data transfer path in a wireless mesh network and a use channel used for data transfer among the same number of channels of the virtual wireless access points included in the data transfer path by an open flow controller function; ,
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The virtual wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow. Yes,
Furthermore,
The virtual wireless access point aggregates and holds the transmission traffic amount as the traffic amount transmitted within a predetermined time in each channel,
The control device, for each virtual wireless access point,
(A2) Obtain the amount of transmission traffic,
(B2) calculating the traffic amount within the predetermined range for each channel by summing the transmission traffic amount of each channel of each virtual wireless access point belonging to the predetermined range, and as a difference between the channels of the traffic amount within the predetermined range Calculate the channel difference,
(C2) One flow from a group of flows transmitted in the channel with the maximum amount of traffic within the predetermined range to the virtual wireless access point with the maximum inter-channel difference among the virtual wireless access points belonging to the predetermined range. And the usage channel is changed so that the selected flow is transmitted on the channel having the smallest traffic amount within the predetermined range.
Wireless mesh network system. The wireless mesh network system according to claim 9, wherein
The virtual wireless access point aggregates and holds the transmission flow traffic volume as the traffic volume for each flow transmitted within the predetermined time in each channel,
The control device includes:
In (A2), the transmission flow traffic volume is acquired together with the transmission traffic volume,
In (C2), when there is a flow having a transmission flow traffic amount within a predetermined coefficient range obtained by multiplying the maximum inter-channel difference among the inter-channel differences by a predetermined coefficient, the transmission flow traffic amount is within the predetermined coefficient range. The flow closest to the upper limit value is selected as the one flow, and the usage channel of the selected flow is changed. When there is no flow with the flow traffic amount within the predetermined coefficient range, the usage channel is changed. Absent,
Wireless mesh network system. The wireless mesh network system according to claim 9 or 10,
The control device includes:
(D2) In the virtual wireless access point having the maximum difference between channels, when the use channel is changed, the flow traffic amount of the flow related to the change is subtracted from the transmission traffic amount of the channel before the change and Add to the amount of outgoing traffic,
(E2) deleting the virtual wireless access point that is the target of the virtual wireless access point having the maximum difference between channels in (C2) from the target of the virtual wireless access point of (C2),
(F2) Repeat (B2) to (E2) until there is no virtual wireless access point target that maximizes the inter-channel difference in (C2).
Wireless mesh network system. The wireless mesh network system according to claim 11,
The control device includes:
(G2) Repeat (B2) to (F2) a predetermined number of times or until the difference between the channels at each virtual wireless access point becomes a predetermined value or less.
Wireless mesh network system. A wireless mesh network system,
By connecting multiple wireless access points in a daisy chain by wire or wireless, it is possible to use the same number of channels as the number of wireless access points at the same time, and it has an open flow switch function and functions as an access point for a wireless mesh network. A virtual wireless access point;
A control apparatus for setting a data transfer path in a wireless mesh network and a use channel used for data transfer among the same number of channels of the virtual wireless access points included in the data transfer path by an open flow controller function; ,
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The virtual wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow. Yes,
Furthermore,
The control device includes:
Distinguishing the channel into a group A of channels including at least one channel and not mainly transmitting / receiving and a group B of channels including at least one channel and mainly transmitting / receiving,
For the new flow, the usage channel is defined so that the channel having the maximum transmission rate among the channels belonging to group A is transmitted.
Wireless mesh network system. A wireless mesh network system,
By connecting multiple wireless access points in a daisy chain by wire or wireless, it is possible to use the same number of channels as the number of wireless access points at the same time, and it has an open flow switch function and functions as an access point for a wireless mesh network. A virtual wireless access point;
A control apparatus for setting a data transfer path in a wireless mesh network and a use channel used for data transfer among the same number of channels of the virtual wireless access points included in the data transfer path by an open flow controller function; ,
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The virtual wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow. Yes,
Furthermore,
The control device includes:
Distinguishing the channel into a group A of channels including at least one channel and not mainly transmitting / receiving and a group B of channels including at least one channel and mainly transmitting / receiving,
For the new flow, the use channel is set so that an expected value obtained by dividing the number of flows that flow through the transmission rate among the channels belonging to group A by the value 1 is transmitted on the maximum channel. Define,
Wireless mesh network system. The wireless mesh network system according to claim 13 or 14 ,
The control device, as an initial value, distinguishes a channel with the lowest transmission rate into the group B and distinguishes the remaining channels into the group A.
Wireless mesh network system. A wireless mesh network system according to any one of claims of claims 13 to 15,
The control device newly adds a channel that has a maximum channel utilization rate of 100% or less when a new flow is transmitted / received on a channel belonging to group B to a new flow whose channel is defined as a channel belonging to group A. Change the flow channel,
Wireless mesh network system. The wireless mesh network system according to claim 16 , wherein
When the usage channel cannot be changed to the channel of group B with respect to a new flow in which the usage channel is defined as a channel belonging to group A, the control device changes the channel defined as the usage channel to the new flow. Change to group B,
Wireless mesh network system. The wireless mesh network system according to claim 16 or 17 ,
When there are two or more channels belonging to group B and there is a channel that is not transmitted / received among the channels belonging to group B, the control device performs transmission / reception among the channels belonging to group B. Change the non-channel to group A,
Wireless mesh network system. A wireless mesh network system,
By connecting multiple wireless access points in a daisy chain by wire or wireless, it is possible to use the same number of channels as the number of wireless access points at the same time, and it has an open flow switch function and functions as an access point for a wireless mesh network. A virtual wireless access point;
A control apparatus for setting a data transfer path in a wireless mesh network and a use channel used for data transfer among the same number of channels of the virtual wireless access points included in the data transfer path by an open flow controller function; ,
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The virtual wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow. Yes,
Furthermore,
The control device defines the use channel so that the remaining rate that is not used for transmission / reception among the plurality of available channels is transmitted with respect to the new flow.
Wireless mesh network system. A wireless mesh network system,
By connecting multiple wireless access points in a daisy chain by wire or wireless, it is possible to use the same number of channels as the number of wireless access points at the same time, and it has an open flow switch function and functions as an access point for a wireless mesh network. A virtual wireless access point;
A control apparatus for setting a data transfer path in a wireless mesh network and a use channel used for data transfer among the same number of channels of the virtual wireless access points included in the data transfer path by an open flow controller function; ,
With
When the control apparatus receives a packet with an undefined flow, the control apparatus uses the packet to identify at least the source IP address, the destination IP address, the transmission port number, and the reception port number among the identification information of layers 1 to 4 Define the flow using
The virtual wireless access point transmits the packet to the control device for a packet with an undefined flow, and transmits the packet to a control channel based on the flow for a packet with a defined flow. Yes,
Furthermore,
The controller is a channel having a maximum expected value obtained by dividing each transmission rate of a plurality of available channels by the number of flows flowing in each channel plus a value of 1 for a new flow. Define the usage channel to be transmitted,
Wireless mesh network system. The wireless mesh network system according to claim 19 or 20 ,
The control device changes the usage channel to a channel that has a maximum channel utilization rate of 100% or less when a new flow is transmitted / received on a channel different from the usage channel for a new flow in which a usage channel is defined.
Wireless mesh network system.

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