JP2010245783A - Mobile router ad-hoc network communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a mobile router ad-hoc network communication system wherein throughput reduction in TCP data communication is suppressed by suppressing excessive operation of TCP congestion control. <P>SOLUTION: When performing TCPProxy processing to a TCP data packet which is received from an IP terminal and is to be transmitted to an ad-hoc network, a terminal MR acquires wireless connection status or wireless transmission band information from an adjacent MR and determines whether or not the TCP data packet can be transmitted on the basis of wireless connection status or wireless transmission band information of a radio channel to be used for transferring the TCP data packet to an MR of the next hop. If a wireless connection status is a disconnected status or a wireless transmission band is zero, useless retransmission control is suppressed by temporarily suspending the transmission of the TCP data packet. If the TCP data packet can be transmitted, a transmission rate of the TCP data packet is restricted to be settled within a transmission enabled rate recognized from the wireless transmission band information. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a mobile router ad hoc network communication system to which a TCP (Transmission Control Protocol) Proxy control system is applied.

  Conventionally, a NEMO (network mobility) function that realizes a mobile network using mobile IP technology has been studied in “IETF NEMO WG”, and RFC3963 relating to NEMO specifications has been formulated (for example, see Non-Patent Document 1).

In this type of conventional system, a router that realizes a mobile network is referred to as an MR (mobile router).
The MR accommodates one or more mobile networks, and an MNN (IP terminal) is connected to the mobile network. An IP terminal need not support mobile IP.

  When an IP terminal transmits an IP packet for an external network, the IP packet is transmitted to a mobile router (MR at the end of the communication path of the network) that accommodates the IP terminal. An IP packet to the network is transmitted to a home agent (HA) that is a device in charge of packet transfer with the external network.

The home agent transmits the IP packet addressed to the external network received from the mobile router toward the external network.
At this time, the mobile router has information (prefix) of the mobile network accommodated by the mobile router and a temporary IP address (care-of address CoA: Care of) that it uses for communication with the home agent in the destination network. Address) is always registered in the home agent.

On the other hand, the home agent transmits an IP packet addressed to the IP terminal under the mobile router to the care-of address of the mobile router.
As a result, the IP terminal can communicate with the external network without being aware of the change in the care-of address due to the movement of the mobile router.

A communication method, a mobile communication node (Node), and an access router in a network system have also been proposed (see, for example, Patent Document 1).
In Patent Document 1, an ad hoc network (mesh network) is connected to an access router by mobile IP technology, and mobile nodes constituting the ad hoc network (mesh network) are connected to the access router via the mesh network. It has a configuration.

  Further, as a technique called MONEMO (Mobile AdHoc Network for Network Mobility), a case where a plurality of mobile routers are connected to each other to form an ad hoc network is also conceivable.

  In this case, each mobile router realizes mobility in IP communication by registering a care-of address to be used at the destination in the home agent and configuring an IP tunnel with the home agent. There is a possibility that another mobile router is connected in multiple stages to the router.

Conventionally, “NEMO WG” has been studied as a means for solving various problems in the multistage configuration of such a mobile router, and an improved technique of “Nested NEMO” has been proposed (for example, non-patented). Reference 2 and non-patent reference 3).
In “IETF AUTOCONF WG”, an architecture and problems when a plurality of MRs configure an ad hoc network are examined (for example, see Non-Patent Document 4).

  In the examination of these problems, “route optimization” is also shown as a problem in which the communication route between mobile routers is a route that does not go through each home agent and is closed in the ad hoc network.

  Further, in a long-distance communication line with a high delay, the TCP throughput is determined by the delay time of the line, and the TCP throughput is kept low even for a wide-band physical line.

In order to improve the TCP throughput reduction problem, a TCP Proxy function has been researched and developed (see, for example, Non-Patent Document 5).
The TCP Proxy function operates between both terminals that establish a TCP connection, and returns an acknowledgment packet (ACK: Acknowledge) in TCP congestion control as a proxy for the opposing IP terminal. is there.

  This makes it possible for the opposite terminal to appear as if it exists in a nearby network, thereby suppressing the TCP congestion control operation caused by the transmission delay time and enabling wide-band long-distance transmission.

  Furthermore, as a related technique, “Media Independent Handover” in which communication is continued by switching between a plurality of different types of wireless communication systems has been discussed. Among them, handover using a wireless connection state change event as “L2 trigger” is discussed. Processing has been proposed (for example, see Non-Patent Document 6).

Hereinafter, problems in the conventional system will be specifically described with reference to FIGS. 33 to 37.
FIG. 33 is an explanatory diagram showing a simple network configuration and shows basic operations related to state information at the layer 2 level from the TCP Proxy and the wireless device.
FIG. 34 is a perspective view showing a mobile router ad hoc network, and shows a problem when the technique of FIG. 33 is applied to a long delay network.

In FIG. 33, router # 1 and router # 2 each accommodating an IP terminal are communicable via a network.
At this time, when communication is performed between the IP terminals accommodated in both routers # 1 and # 2 using TCP, TCP termination processing operates in both terminals, and the broken-lined double-pointed arrow in FIG. A TCP connection is established in the section.

  Also, when the network transmission delay time is large, the TCP processing is divided at the position corresponding to the routers # 1 and # 2, so that the IP terminal is connected between the router # 1 and the router # 2. TCP Proxy technology (or TCP split architecture) is known that makes the transmission delay time unconscious.

FIG. 35 is an explanatory diagram showing the location of the TCP Proxy section, and shows the TCP Proxy section (dashed double arrow) when the TCP Proxy technology is applied to the simple network as shown in FIG.
FIG. 36 is an explanatory diagram showing the location of a TCP Proxy section when a wireless section is included.

  Such TCP Proxy processing is not only performed when the network has a long delay as shown in FIG. 35, but the network is configured with a wireless system as shown in FIG. It is effective even in the case of fluctuation.

  The wireless system in FIG. 36 has a function of adaptively changing the transmission band so that reliable information transmission is possible according to the wireless environment at that time. Also, depending on the positional relationship between the wireless devices, wireless connection may not be possible.

  In such a case, in the TCP Proxy process, the TCP packet can be transferred according to the change in the connection state of the wireless section by the TCP packet retransmission process. However, in the case of such a configuration, by retransmitting the information on the connection state of the wireless section and the transmittable bandwidth from the wireless device to the router device that executes the TCP Proxy processing, retransmission of the TCP packet in the TCP Proxy processing of the router device It is possible to suppress an excessive operation of the process.

FIG. 37 is an explanatory diagram showing the location of a TCP Proxy section when cooperating with a wireless device, and shows a TCP Proxy section (see dotted arrows) that uses wireless information from the wireless device.
This realizes a configuration that suppresses excessive operation of TCP packet retransmission processing in the TCP Proxy processing of the router device.

  However, when the conventional TCP Proxy process adaptable to the state in the wireless section is applied to the mobile router ad hoc network as shown in FIG. 34, the IP accommodated by the two mobile routers (# 1, # 2) constituting the ad hoc network In the communication path between terminals (MNN), there are a plurality of wireless sections as shown in FIG. Further, the communication path may change due to the ad hoc path control operation of the ad hoc network.

  As described above, the transmittable bandwidth and the transmission delay time in the communication path between the IP terminals (MNN) change in places where the mobile router that accommodates the IP terminal (MNN) cannot know, so the TCP packet retransmission process by the TCP Proxy process. There is a problem that it is not possible to effectively suppress the excessive movement of.

Special table 2008-524908

IETF RFC3963 “Network Mobility (NEMO) Basic Support Protocol” Jan 2005 IETF RFC4888 "Network Mobility Route Optimization Problem Statement" July 2007 IETF RFC4889 “Network Mobility Route Optimization Solution Space Analysis” July 2007 IETF draft “Mobile Ad Hoc Network Architecture draft-ietf-autoconf-manetarch-05” Aug 2007 "Proxy Proxy Mechanism for TCP Connection Multiplexing in Satellite Internet" IEICE Technical Report. IN, Information Network, Vol. 101, no. 716, pp. 69-76. “IEEE 802.21 Overview of Standard for Dependent Handover Services” http: // www. iee802. org / 21 / Tutorials / 802% 2021-IEEE-Tutorial. ppt, July 18 2006

  In the conventional mobile router ad hoc network communication system, when TCP Proxy processing is applied to the mobile router ad hoc network in FIG. 34, a plurality of communication paths are provided between IP terminals (MNN) accommodated by two mobile routers constituting the ad hoc network. Since there is a wireless section and the communication path is changed by the ad hoc route control operation of the ad hoc network, the transmittable bandwidth and transmission delay time in the communication path between IP terminals (MNN) accommodates the IP terminal (MNN). However, there is a problem that the excessive operation suppression effect of the TCP packet retransmission process by the TCPProxy process cannot be sufficiently realized.

  The present invention has been made to solve the above-described problems. In a terminal mobile router (MR) that accommodates both terminals (IP terminals: MNN), between both terminals (MNN) in a mobile router ad hoc network. It is efficient when a plurality of MRs constitute an ad hoc network by operating the TCPProxy function based on the wireless connection state or wireless transmission band information of the wireless circuit on the route to which the TCP packet of the TCP connection is transferred. An object is to obtain a mobile router ad hoc network communication system that realizes TCP packet transfer.

A mobile router ad hoc network communication system according to the present invention is accommodated under the control of a plurality of mobile routers that are connected to each other by a wireless system to form an ad hoc network and each terminal mobile router located at both ends of the communication path of the ad hoc network. A mobile router ad hoc network communication system that realizes IP communication between IP terminals of each terminal mobile router,
Each of the plurality of mobile routers includes a TCP proxy function for performing TCP congestion control and TCP retransmission control. The TCP proxy function of the terminal mobile router includes first and second functions, and is an intermediate mobile router located in the middle of the communication path. The TCPProxy function includes a third function,
The first function of the terminal mobile router is
Recognizing the first TCP connection of the first TCP data packet received from the IP terminal, determining whether the first TCP connection is to be a TCP Proxy processing target,
When the first TCP connection is a TCP Proxy processing target, the TCP ACK packet for the first TCP data packet is replaced with the first IP data destination IP terminal that is the destination of the first TCP data packet. To the first source IP terminal of the TCP data packet,
The first TCP data packet received from the first source IP terminal is forwarded to the mobile router as the next hop determined by the ad hoc route control of the ad hoc network, and the transferred TCP data packet is temporarily stored.
In response to the TCP data packet retransmission request from the TCP Proxy function of the destination IP terminal or the mobile router accommodating the destination IP terminal, the transferred TCP data packet temporarily stored is retransmitted on behalf of the IP terminal,
The second function of the terminal mobile router is
Recognize the second TCP connection of the second TCP data packet addressed to the IP terminal received from the adjacent mobile router of the terminal mobile router, and determine whether or not the second TCP connection is to be a TCP Proxy processing target And
If the second TCP connection is a TCP Proxy processing target, the second TCP data packet is temporarily stored, and the second TCP connection is temporarily stored using the TCP sequence number stored in the second TCP data packet. 2 inspect the order of the TCP data packets and send the second TCP data packet to the IP terminal in the correct order;
If the second TCP data packet is missing based on the inspection result by the TCP sequence number, the missing second TCP data packet is addressed to the second source IP terminal of the second TCP connection. Request a resend of
The third function of the intermediate mobile router is
Recognizing the third TCP connection of the third TCP data packet received from the adjacent mobile router of the intermediate mobile router and addressed to the IP terminal accommodated by the other mobile router, the third TCP connection is set as the TCP Proxy relay processing target. Determine whether it should be,
When the third TCP connection is a TCP Proxy relay processing target, the received third TCP data packet is forwarded to the next-hop mobile router.
In a mobile router ad hoc network communication system,
The TCP Proxy function of the terminal mobile router further includes a fourth function,
The fourth function of the terminal mobile router is
When performing TCPProxy processing on the first to third TCP data packets received from the IP terminal and transmitted to the ad hoc network,
Obtain wireless connection status or wireless transmission band information between adjacent mobile routers from wireless devices that perform wireless connection with adjacent mobile routers directly connected to the terminal mobile router,
The next-hop mobile router via the wireless device based on the wireless connection state or wireless transmission bandwidth information of the wireless line used when transferring the first to third TCP data packets to the next-hop mobile router Determining whether or not to transmit the first to third TCP data packets scheduled to be transmitted to the destination;
When the wireless connection state between a plurality of mobile routers interconnected in the ad hoc network is temporarily disconnected, or when the wireless transmission band is zero, the first to third TCP data packets are transmitted. Suppressing unnecessary retransmission control by temporarily stopping,
When the wireless connection state between the plurality of mobile routers is the connection state and the wireless transmission band is not zero, the first transmission rate is determined so that it is within the transmittable rate recognized from the wireless transmission band information obtained from the wireless device. The transmission rate of the first to third TCP data packets is limited.

  According to the present invention, when TCP data communication is performed between IP terminals in an ad hoc network in which a plurality of mobile routers are interconnected using a wireless system, the terminal MR (the end of the path accommodating the IP terminal) The TCP Proxy function of the mobile router) can suppress the TCP congestion control from being excessively operated by the TCP connection, and can suppress a decrease in throughput in the TCP data communication due to the excessive TCP congestion control.

It is a functional block diagram which shows the principal part of the mobile router ad hoc network communication system which concerns on Embodiment 1 of this invention. It is a perspective view for demonstrating the operation example reflecting the radio | wireless state by Embodiment 1 of this invention. It is a perspective view for demonstrating the outline | summary in the case of cooperating with the radio | wireless apparatus by Embodiment 1 of this invention. FIG. 4 is an explanatory diagram showing an operation at the time of reception of “radio link disconnection” by the terminal MR in FIG. 3; It is a flowchart which shows operation | movement of each MR at the time of the reception of the "radio link disconnection" by Embodiment 1 of this invention. It is explanatory drawing which shows operation | movement of the terminal MR at the time of the "radio link establishment" reception after the "radio link disconnection" reception by Embodiment 1 of this invention. It is a flowchart which shows operation | movement of each MR at the time of the "radio link establishment" reception by Embodiment 1 of this invention. It is a perspective view for demonstrating the operation example reflecting the radio | wireless link disconnection generation | occurrence | production state by Embodiment 2 of this invention. FIG. 9 is an explanatory diagram showing the operation of each MR when “radio link disconnection” is notified from the intermediate MR in FIG. 8; It is explanatory drawing which shows operation | movement of intermediate | middle MR when the "radio link establishment" return information by Embodiment 2 of this invention is notified. It is a perspective view for demonstrating the establishment operation | movement of the detour path in the middle of the path | route by Embodiment 3 of this invention. It is explanatory drawing which shows operation | movement of intermediate | middle MR at the time of the establishment of the detour route by Embodiment 3 of this invention. It is explanatory drawing which shows operation | movement of intermediate | middle MR when the detour route establishment information is notified from adjacent MR by Embodiment 3 of this invention. It is a flowchart which shows operation | movement of each MR which established the detour route by Embodiment 3 of this invention. It is a flowchart which shows operation | movement of each MR when the radio | wireless information notification (detour route establishment) by Embodiment 3 of this invention is received. It is a perspective view for demonstrating the operation | movement at the time of intermediate | middle MR failure by Embodiment 4 of this invention. It is a perspective view for demonstrating the operation | movement at the time of the establishment of the alternative path | route by Embodiment 4 of this invention. It is explanatory drawing which shows operation | movement of intermediate | middle MR at the time of "route control start" transmission by Embodiment 4 of this invention. It is a flowchart which shows operation | movement of each MR at the time of "route control start" reception by Embodiment 4 of this invention. It is explanatory drawing which shows the operation | movement at the time of the reset of the TCP connection by Embodiment 4 of this invention. It is a flowchart which shows operation | movement of each MR at the time of reset of the TCP connection by Embodiment 4 of this invention. It is a perspective view for demonstrating the operation | movement at the time of the band change by Embodiment 5 of this invention. It is explanatory drawing which shows operation | movement of intermediate | middle MR at the time of the "band change" reception in Embodiment 5 of this invention. It is a flowchart which shows operation | movement of each MR when a transmission band is changed by the radio link by Embodiment 5 of this invention. It is a perspective view for demonstrating the TCPProxy area for collecting the routing information in Embodiment 6 of this invention. It is explanatory drawing which shows the routing information collection operation | movement by the terminal MR in FIG. It is explanatory drawing which shows the routing information collection operation | movement at the time of the new route establishment by the terminal MR of Embodiment 6 of this invention. It is explanatory drawing which shows operation | movement of intermediate | middle MR at the time of the "route information collection message" reception by Embodiment 6 of this invention. It is a flowchart which shows operation | movement of each MR at the time of the "route information collection message" reception by Embodiment 6 of this invention. It is explanatory drawing which shows operation | movement of the terminal MR at the time of the "route information collection message" reception by Embodiment 6 of this invention. It is a flowchart which shows operation | movement of each MR at the time of "Route information notification message" reception by Embodiment 6 of this invention. It is explanatory drawing which shows operation | movement of the terminal MR at the time of the "route information notification message" reception by Embodiment 6 of this invention. It is explanatory drawing which shows the simple network structure in a conventional system. It is a perspective view which shows the mobile router ad hoc network in a conventional system. It is explanatory drawing which shows the location of the TCPProxy area in a conventional system. It is explanatory drawing which shows the location of the TCPProxy area in the case of including the wireless area in a conventional system. It is explanatory drawing which shows the location of the TCPProxy area in the case of cooperating with a wireless device in a conventional system.

Embodiment 1 FIG.
FIG. 1 is a functional block diagram showing a main part of a mobile router ad hoc network communication system according to Embodiment 1 of the present invention, and shows a basic configuration in an MR (mobile router) constituting the mobile router ad hoc network communication system. .

  In FIG. 1, a mobile router ad hoc network communication system provided in each of a plurality of MR (mobile routers) includes a TCP flow determination / TCP packet transfer processing unit 1, a local port transmission / reception processing unit 2 for MNN (IP terminal), The inter-MR ad hoc network port transmission / reception processing unit 3, the radio state management unit 4, the ad hoc route control unit 5, and the IP packet processing unit 6 are provided.

The local port transmission / reception processing unit 2 for MNN and the inter-MR ad hoc network port transmission / reception processing unit 3 are configured to be able to transmit and receive wirelessly with other MRs (see FIG. 2).
The local port transmission / reception processing unit 2 for MNN is configured to be able to transmit / receive to / from the TCP flow determination / TCP packet transfer processing unit 1, and performs IP packet transmission / reception with each MNN (IP terminal) accommodated by the MR. Do.

  The inter-MR ad hoc network port transmission / reception processing unit 3 is configured to be able to transmit / receive to / from the TCP flow determination / TCP packet transfer processing unit 1 via the wireless state management unit 4, the ad hoc route control unit 5, and the IP packet processing unit 6. IP packet transmission / reception between MRs is performed via a wireless device connected to the MR.

The wireless state management unit 4 is interposed between the TCP flow determination / TCP packet transfer processing unit 1 and the inter-MR ad hoc network port transmission / reception processing unit 3, and is connected to the wireless device connected to the MR (mobile router) and other devices. Transmit and receive wireless information from the mobile router.
The wireless state management unit 4 manages information on the wireless line between the mobile routers, notifies the TCP flow determination / TCP packet transfer processing unit 1 of a bandwidth usable in TCP, and transfers TCP packets. Instruct whether or not it is possible.

  The ad hoc route control unit 5 is interposed between the TCP flow determination / TCP packet transfer processing unit 1 and the inter-MR ad hoc network port transmission / reception processing unit 3 and is configured to be able to communicate with the radio state management unit 4. And performs ad hoc route control between mobile routers in an ad hoc network composed of a plurality of mobile routers.

  The IP packet processing unit 6 is interposed between the TCP flow determination / TCP packet transfer processing unit 1 and the inter-MR ad hoc network port transmission / reception processing unit 3, and performs IP packet transfer in the mobile router.

Next, with reference to FIG. 2, an example of operation reflecting the radio state at the route end point according to the first embodiment of the present invention will be specifically described.
FIG. 2 is a perspective view for explaining an operation example reflecting a radio state according to Embodiment 1 of the present invention.
In the mobile router ad hoc network of FIG. 2, when performing TCP communication between IP terminals (MNN1, MNN7) accommodated in different mobile routers (MR1, MR7) located at both ends of a communication path (TCPProxy section). The basic form of TCP Proxy processing is shown.

  In FIG. 2, the MNN connected to the MR (mobile router) in the middle of the communication path (ad hoc network) between the MNNs (IP terminals) is omitted, but in the TCP Proxy section constituting the ad hoc network. A plurality of MRs (each MR including both ends and midway of the communication path) are provided with MNNs associated with them.

  Each of the plurality of MRs is provided with a wireless device for TCP communication. Furthermore, as shown in the figure, MNN1 and MNN7 are accommodated in MR1 and MR7 located at both ends of the communication path.

  MR1 and MR7 that accommodates MNN1 and MNN7 perform TCPProxy processing to form a TCPProxy section (broken-line double-headed arrow) between MR1 and MR7, and change in radio quality in the TCPProxy section, or temporarily by the ad hoc path control unit 5 By preventing both terminals (MNN) from being aware of a typical packet transfer stop, excessive operation of TCP congestion control in the IP terminal is suppressed.

  In the configuration of FIG. 2, the MR1 and MR7 that accommodate the MNN1 and MNN7 acquire wireless connection state information from the wireless device by wireless information notification, and execute TCP Proxy processing using the wireless connection state information. This suppresses unnecessary retransmission control in a state where the connection between adjacent MRs is temporarily disconnected.

FIG. 3 is a perspective view for explaining an outline in the case of cooperating with a wireless device, and shows a TCP Proxy section (see a dotted arrow) of an ad hoc network using wireless information from the wireless device.
In FIG. 3, MR1 and MR7 configuring the TCPProxy section acquire wireless information notification (see solid line arrows) from the respective wireless devices.

  FIG. 4 is an explanatory diagram showing the operation of the terminal MR (MR1, MR7) in FIG. 3 superimposed on the block diagram of FIG. 1. In the terminal MR accommodating the MNN, the wireless communication between the MRs from the wireless device or the adjacent MR is performed. The operation when a wireless information notification (wireless link disconnection) indicating that the connection state is temporarily disconnected is received is shown.

  In FIG. 4, a thick arrow indicates an operation when information indicating “radio link disconnection” is notified from the radio apparatus, and radio information notification (radio link disconnection) notified from the radio apparatus to the MR is MR. The data is transferred to the wireless state management unit 4 by the inter-ad hoc network port transmission / reception processing unit 3.

  The wireless state management unit 4 recognizes that the packet transmission from the MR to the ad hoc network is temporarily impossible by the wireless information notification (wireless link disconnection) transferred from the inter-MR ad hoc network port transmission / reception processing unit 3. The TCP flow determination / TCP packet transfer processing unit 1 is instructed to stop the packet transfer addressed to the ad hoc network port.

  As a result, the TCP flow determination / TCP packet transfer processing unit 1 stops the packet transfer from the IP terminal to the ad hoc network for the TCP packet of the TCP flow passing through the instructed ad hoc network port.

  When the terminal MR according to Embodiment 1 of the present invention performs a TCP Proxy process on a TCP data packet received from an MNN (IP terminal) and transmitted to an ad hoc network, the terminal MR transmits a wireless connection state or wireless transmission band information. And determining whether or not the TCP data packet can be transmitted based on the wireless connection state or wireless transmission band information of the wireless line used when the TCP data packet is transferred to the next-hop MR. In the disconnected state (or the wireless transmission band is zero), transmission of TCP data packets is temporarily stopped to suppress unnecessary retransmission control. When transmission is possible, it is recognized from the wireless transmission band information. The transmission rate of TCP data packets is limited so as to be within the transmission possible rate.

Next, referring to the flowchart of FIG. 5, the operation of each MR when “radio link disconnection” is received as the radio information notification as shown in FIG. 4 will be described more specifically.
The feature of the first embodiment of the present invention corresponds to the operation when the MR determines that “the position of its own device on the path is the path end” in the processing flow (step S3) of FIG.

In the process at the time of detecting the radio link disconnection in FIG. 5, the MR first receives a radio information notification (radio link disconnection) from the radio apparatus or upstream of the path (step S1), refers to the path information (step S2), and The position on the route is determined (step S3).
Here, “wireless link disconnection” is detected when the wireless connection state between MRs is temporarily disconnected, but “wireless link disconnection” is detected when the wireless transmission band between MRs is zero. May be.

  In step S3, if it is determined that the position on the route of the device is “route intermediate (intermediate position in the middle of communication route)”, a wireless information notification (wireless link disconnection) is transmitted toward the downstream of the route (step S3). S4), the processing of FIG. 5 is terminated and the next processing wait state is entered. Step S4 relates to the operation of the second embodiment described later.

  On the other hand, if it is determined in step S3 that the position of the own device on the path is “path end (end position of communication path)”, TCP packet transfer from the MNN to the ad hoc network is temporarily stopped (step S3). S5) The next processing wait state is entered.

  FIG. 6 is an explanatory diagram showing the operation of the terminal MR upon reception of “radio link disconnection” after reception of “radio link disconnection” (FIGS. 4 and 5). The operation when the MR that has stopped the packet transfer accordingly receives a wireless information notification (wireless link establishment) from the wireless device or the adjacent MR is indicated by a thick arrow.

  In FIG. 6, the wireless information notification (wireless link establishment) notified from the wireless device to the MR is transferred to the wireless state management unit 4 by the inter-MR ad hoc network port transmission / reception processing unit 3, and the wireless state management unit 4 Recognize that packet transmission from MR to ad hoc network is possible by notification of information (establish radio link), and instruct TCP flow judgment / TCP packet transfer processing unit 1 to resume packet transfer addressed to ad hoc network port To do.

  As a result, the TCP flow determination / TCP packet transfer processing unit 1 resumes the packet transfer addressed to the ad hoc network from the IP terminal for the TCP packet of the TCP flow passing through the instructed ad hoc network port.

Next, referring to the flowchart of FIG. 7, the operation of each MR when “radio link establishment” is received as the radio information notification as shown in FIG. 6 will be described more specifically.
As described above, the feature of the first embodiment of the present invention corresponds to the operation when the MR determines that “the position on the route of its own device is the route end” in the processing flow (step S3) of FIG. To do.

In the wireless link establishment detection process of FIG. 7, steps S2 and S3 are the same processes as described above (see FIG. 5).
First, the MR receives wireless information notification (established wireless link) from the wireless device or upstream of the route (step S11), refers to the route information (step S2), and determines the position of the own device on the route (step S3). ).

  If it is determined in step S3 that the position of the own device on the route is “route intermediate”, a wireless information notification (wireless link establishment) is transmitted downstream (step S14), and the processing of FIG. Ends and waits for the next processing. Note that step S14 relates to the processing operation of the second embodiment described later.

  On the other hand, if it is determined in step S3 that the position of the own device on the route is “route end”, the TCP packet transfer from the MNN to the ad hoc network is resumed (step S15), and the next processing waiting state is set. Become.

  As described above, the mobile router ad hoc network communication system according to Embodiment 1 (FIGS. 1 to 7) of the present invention includes a plurality of mobile routers that are connected to each other by a wireless system to form an ad hoc network, and the ad hoc network. IP terminals (MNN1, MNN7) accommodated under each of terminal mobile routers (MR1, MR7) located at both ends of the communication path of the network, and realizes IP communication between the IP terminals (MNN1, MNN7) .

  Each of the plurality of mobile routers has a TCP proxy function for performing TCP congestion control and TCP retransmission control. The TCP proxy function of the terminal mobile router (MR1, MR7) includes first and second functions, and includes a communication path. The TCP Proxy function of the intermediate mobile router located in the middle includes a third function.

  The first function of the terminal mobile router (MR1, MR7) recognizes the first TCP connection of the first TCP data packet received from the IP terminal (MNN1, MNN7), and the first TCP connection performs TCP Proxy processing. It is determined whether or not to be a target, and when the first TCP connection is a TCP proxy processing target, a TCPACK packet for the first TCP data packet is changed to a destination that is a destination of the first TCP data packet. Instead of the IP terminal, the first TCP data packet is returned to the first source IP terminal.

  The first function transfers the first TCP data packet received from the first source IP terminal to the mobile router that is the next hop determined by the ad hoc route control of the ad hoc network, and the transferred TCP data. The packet is temporarily stored, and the transferred TCP data packet temporarily stored in response to the TCP data packet retransmission request from the TCP Proxy function of the destination IP terminal or the mobile router accommodating the destination IP terminal is sent to the IP terminal. Resend on behalf.

  The second function of the terminal mobile router (MR1, MR7) recognizes the second TCP connection of the second TCP data packet addressed to the IP terminal received from the adjacent mobile router, and the second TCP connection performs TCP proxy processing. It is determined whether or not to be a target, and if the second TCP connection is a TCP proxy processing target, the second TCP data packet is temporarily stored and stored in the second TCP data packet. The order of the second TCP data packet temporarily stored is checked using the TCP sequence number that is stored, and the second TCP data packet is transmitted to the IP terminal in the correct order.

  The second function is based on the inspection result by the TCP sequence number, and when the second TCP data packet is missing, the second function is missing to the second source IP terminal of the second TCP connection. Requesting retransmission of the second TCP data packet.

  On the other hand, the third function of the intermediate mobile router recognizes the third TCP connection of the third TCP data packet received from the adjacent mobile router of the intermediate mobile router and addressed to the IP terminal accommodated by the other mobile router. , It is determined whether or not the third TCP connection is to be a TCP Proxy relay process target. If the third TCP connection is a TCP Proxy relay process target, the received third TCP data packet is Forward to the hop mobile router.

  In the mobile router ad hoc network communication system, the TCP Proxy function of the terminal mobile router (MR1, MR7) further includes a fourth function, and the fourth function of the terminal mobile router is received from the IP terminal (MNN1, MNN7). When performing the TCP Proxy process on the first to third TCP data packets transmitted to the ad hoc network, the wireless device that performs wireless connection with the adjacent mobile router directly connected to the terminal mobile router Obtain wireless connection status or wireless transmission bandwidth information with the mobile router.

  The fourth function of the terminal mobile router is based on the wireless connection state or wireless transmission band information of the wireless line used when the first to third TCP data packets are transferred to the next-hop mobile router. The wireless communication between a plurality of mobile routers interconnected in an ad hoc network is determined by determining whether or not the first to third TCP data packets scheduled to be transmitted to the next-hop mobile router via a wireless device are transmitted. When the connection state is temporarily disconnected or when the wireless transmission band is zero, unnecessary retransmission control is suppressed by temporarily stopping transmission of the first to third TCP data packets. .

  Further, the fourth function of the terminal mobile router is that the wireless connection state between the plurality of mobile routers is the connection state and the wireless transmission band is not zero, from the wireless transmission band information obtained from the wireless device. The transmission rates of the first to third TCP data packets are limited so as to be within the recognized transmittable rate.

  In this way, by operating the TCP Proxy function in both terminals (IP terminals: MNN), a mobile router ad hoc network communication system that realizes efficient TCP packet transfer when a plurality of MRs constitute an ad hoc network is obtained. Can do.

  That is, in an ad hoc network in which a plurality of mobile routers are interconnected using a wireless system, when TCP data communication is performed between IP terminals, mobile routers (MR1, MR7 at the end of the path accommodating the IP terminals). ) To suppress the TCP congestion control from being excessively operated by the TCP connection, thereby suppressing a decrease in throughput in the TCP data communication due to the excessive TCP congestion control.

Embodiment 2. FIG.
In the first embodiment (FIGS. 1 to 7), the operation example (steps S5 and S15 in FIG. 5 and FIG. 7) reflecting the wireless state at the path end has been described. 7 and FIG. 8 to FIG. 10, an operation example according to the second embodiment of the present invention reflecting the radio state in the middle of the route will be described.

  In Embodiment 2 of the present invention, when a plurality of wireless sections are included in a TCP Proxy section in an ad hoc network, MR2, MR3, and MR5 (mobile routers) in the middle of a path that does not directly accommodate an MNN (IP terminal) The wireless state of the wireless section in between is notified to MR1 and MR7 (mobile routers) at the path ends executing the TCPProxy process.

  In this way, by allowing the MR1 and MR7 (mobile routers), which are the end points of the TCPProxy section, to recognize that “wireless link disconnection (or the wireless transmission band is zero)” has occurred on the communication path, It is possible to execute TCP Proxy processing adapted to the state.

  In the third and fourth embodiments, which will be described later, the middle MR4 and MR6 of the route are mobiles used when establishing a detour route or an alternative route when the middle MR2, MR3, and MR5 constituting the ad hoc network fail. It is a router.

  FIG. 8 is a perspective view for explaining an operation example reflecting a radio state according to the second embodiment of the present invention. The same reference numerals as those described above are attached to the same components as those described above (see FIGS. 2 and 3). Detailed description is omitted. In this case, an operation in the case where a “wireless link disconnection” (refer to a cross mark and a dotted line) occurs in the middle of the TCPProxy section (broken broken line double arrow) is shown.

  In FIG. 8, when communication using TCP is performed between IP terminals (MNN1 and MNN7), a TCP Proxy section between MR1 accommodating MNN1 and MR7 accommodating MNN7. (Broken line double-pointed arrow) is configured, and MR1 and MR7 are executing TCPProxy processing in the TCP connection between MNN1 and MNN7.

  At this time, in the state where the communication path between MR1 and MR7 passes through MR2, MR3 and MR5 as shown in FIG. 8, an abnormality occurs in the radio link between MR2 and MR3. When communication becomes impossible due to "link disconnection", MR2 notifies MR1 which is the end point of one TCPProxy section that "radio link disconnection" from MR2 to MR3 has occurred by wireless information notification. .

At the same time, MR3 notifies MR7, which is the end point of the other TCPProxy section, that a “radio link disconnection” has occurred.
When receiving the wireless information notification from MR2 and MR3, MR1 and MR7, which are the end points of the TCPProxy section, temporarily stop the TCP packet transfer between MR1 and MR7, and prevent unnecessary TCP packet retransmission into the ad hoc network. To do.

Further, when the “wireless link disconnection” between MR2 and MR3 is recovered within a predetermined time, MR2 and MR3 send a wireless information notification to MR1 and MR7 in the same manner as described above. Notify "Establish wireless link".
Thereafter, in response to the wireless information notification from MR2 and MR3, MR1 and MR7 resume TCP packet transfer.

  Here, referring to FIG. 9 together with FIG. 8, in the intermediate MR (MR2, MR3 in FIG. 8) that does not directly accommodate the MNN on the communication path, the wireless device of the intermediate MR “wirelessly” The operation of each MR (MR1, MR5, MR7 in FIG. 8) when the “link broken” information is notified will be described.

  FIG. 9 is an explanatory diagram showing the operation according to the second embodiment of the present invention by a thick arrow in the block diagram. The same reference numerals as those described above are attached to the same components as those described above (see FIGS. 4 and 6). Detailed description is omitted. The system configuration according to Embodiment 2 of the present invention is the same as that of Embodiment 1 described above.

  8 and 9, first, the wireless information notification (radio link disconnection) notified to the adjacent MR (MR1 or MR5) from the radio apparatus of MR (MR2 or MR3) in which the “radio link disconnection” has occurred is indicated by a thick arrow. As described above, first, the data is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 to the wireless state management unit 4.

  Subsequently, the wireless state management unit 4 refers to the route information held by the ad hoc route control unit 5 and temporarily cannot transfer packets in the ad hoc network between MRs by the notified wireless information notification (wireless link disconnection). The wireless information notification (radio link disconnection) is transmitted to the MR (MR1 or MR7) located at the route end point of the ad hoc network.

Further, in the MR on the route that does not accommodate the MNN (IP terminal), the same operation as described above is performed when the adjacent MR is notified of “radio link disconnection” information.
That is, the wireless information notification (radio link disconnection) notified from the adjacent MR is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 to the wireless state management unit 4, and the wireless state management unit 4 has the ad hoc route control unit 5 By referring to the stored route information, it is recognized that the packet transfer in the ad hoc network between the MRs is temporarily disabled by the wireless information notification (radio link disconnection), and the MR (MR1) located at the route end point of the ad hoc network is recognized. Alternatively, the wireless information notification (wireless link disconnection) is transferred to MR7).

  Here, the operation of each MR in FIG. 8 and FIG. 9 will be described with reference to the flowchart in FIG. 5 described above. The feature of the second embodiment of the present invention is that in the processing flow (step S3) in FIG. This corresponds to the processing operation in step S4 when the MR determines that “the position on the route of the own device is in the middle of the route”.

Next, the operation of the intermediate MR when the return information of “wireless link establishment” is notified from the wireless device will be described with reference to FIG.
FIG. 10 is an explanatory diagram showing the operation according to the second embodiment of the present invention with a thick line arrow in the block diagram, and the MR that has stopped the packet transfer due to the detection of the “radio link disconnection” thereafter transmits from the radio device. The operation when the return information of “wireless link establishment” is notified is shown.

  In FIG. 10, the wireless information notification (established wireless link) notified from the wireless device of the adjacent MR to the MR is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 to the wireless state management unit 4.

  As a result, the wireless state management unit 4 refers to the route information held by the ad hoc route control unit 5 and is ready to transfer packets in the ad hoc network between MRs by wireless information notification (wireless link establishment). And wireless information notification (radio link establishment) is transmitted to the MR (MR1 or MR7) located at the route end point of the ad hoc network.

The operation when the return information of “establish radio link” is notified from the adjacent MR in the MR on the route not accommodating the MNN (IP terminal) is the same.
That is, the wireless information notification (established wireless link) notified from the adjacent MR is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 to the wireless state management unit 4, and the wireless state management unit 4 is connected to the ad hoc route control unit 5. Referring to the stored route information, the wireless information notification (radio link establishment) recognizes that packet transfer in the ad hoc network between the MRs is possible, and MR (MR1 or MR1) located at the route end point of the ad hoc network The MR information is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 toward the MR 7).

  Here, the operation of the intermediate MR of FIG. 10 will be described with reference to the flowchart of FIG. 7 described above. The feature of the second embodiment of the present invention is that the MR is “in the processing flow (step S3) of FIG. This corresponds to the processing operation of step S14 when it is determined that the position of the own device on the route is in the middle of the route.

  As described above, in the mobile router ad hoc network communication system according to the second embodiment (FIGS. 8 to 10) of the present invention, the intermediate mobile router (MR2, MR3, MR5) is the terminal mobile router (MR1, MR7). , Wireless in a wireless device directly connected to an intermediate mobile router when performing TCP Proxy processing on the first to third TCP data packets received from the IP terminals (MNN1, MNN7) and transmitted to the ad hoc network A mobile terminal located in the path direction opposite to the direction in which the connection state (wireless link disconnection) or wireless transmission band information (band zero) is transmitted via the wireless device of the intermediate mobile router in the communication path of the ad hoc network Transmit to the router (MR1, MR7).

  Further, each intermediate mobile router, when receiving a packet for notifying the wireless connection state or the wireless transmission band information from the adjacent mobile router, transfers the packet to the next-hop mobile router according to the communication path of the ad hoc network.

  In response to this, the fourth function of the terminal mobile router (MR1, MR7) acquires the wireless connection state or the wireless transmission band information in the wireless device directly connected to the intermediate mobile router from the intermediate mobile router, When the first to third TCP data packets are forwarded to the next-hop mobile router, the wireless connection state or wireless transmission band information in a plurality of wireless devices on the communication path of the ad hoc network is used to pass through the communication path. Then, it is determined whether or not the first to third TCP data packets scheduled to be transmitted can be transmitted.

  The fourth function of the terminal mobile router is that when one of the wireless connection states between the plurality of mobile routers is temporarily disconnected depending on the determination result of whether transmission is possible, or any one of the wireless transmission bands is zero. In some cases, unnecessary retransmission control is suppressed by temporarily stopping the transmission of the first to third TCP data packets.

Further, the fourth function of the terminal mobile router is that when the wireless connection state between the mobile routers constituting the communication path in the ad hoc network is the connection state based on the determination result of the transmission permission / inhibition, a plurality of mobile routers on the communication path The transmission rates of the first to third TCP data packets are limited so as to be within the transmission possible rate in the communication path recognized from the obtained wireless transmission band information.
In this way, by performing an operation reflecting the wireless state in the middle of the path, it is possible to execute TCP Proxy processing adapted to the wireless state.

Embodiment 3 FIG.
In the second embodiment (FIGS. 8 to 10), the establishment of the detour route when the radio link is broken is not mentioned, but even if the detour route is established in the middle of the route as shown in FIG. Good.
Hereinafter, a third embodiment of the present invention in which a detour path is established will be described with reference to FIGS.

FIG. 11 is a perspective view for explaining an operation example when establishing a detour route in the middle of the route, and the same components as those described above (see FIG. 8) are denoted by the same reference numerals as those described above, and detailed description thereof is omitted.
FIG. 12 is an explanatory diagram showing the operation of the intermediate MR at the time of establishing a bypass route according to the third embodiment of the present invention with a thick arrow in the block diagram.

In FIG. 11, according to the third embodiment of the present invention, when MR2 and MR3 determine that the radio link between MR2 and MR3 cannot be recovered, MR4 is set as a detour path between MR2 and MR3. Establish a route through.
At this time, MR2 notifies the wireless information and notifies wireless information “establishment of a detour route from MR2 to MR3” to MR1, which is an end point of one TCPProxy section.

Similarly, MR3 notifies wireless information to MR7 which is the end point of the other TCP Proxy section, and notifies "establishment of a detour route from MR2 to MR3".
The terminal mobile routers (MR1, MR7) that have received the wireless information notifications from MR2 and MR3 resume TCP packet transfer between MR1 and MR7.

FIG. 12 shows the operation of an intermediate MR (mobile router that does not accommodate IP terminals) in the communication path of the ad hoc network. When a path with the adjacent MR is not restored due to “wireless link disconnection”, a bypass path is established. This shows a transmission operation of wireless information (establishment of a bypass route) between adjacent MRs.
In FIG. 12, the same components as those described above (see FIGS. 9 and 10) are denoted by the same reference numerals as those described above, and detailed description thereof is omitted.

  First, the ad hoc route control unit 5 in the intermediate MR (for example, MR3 in FIG. 11) performs ad hoc route control with another mobile router (for example, MR4) capable of ad hoc route control processing in the ad hoc network. When a new detour route is established after execution, the wireless state management unit 4 is notified that “the detour route has been established”.

  Upon receiving the route establishment from the ad hoc route control unit 5, the wireless state management unit 4 indicates that the detour route has been established in the ad hoc network between MRs by the wireless information notification (establishment of the detour route) as a route end point of the ad hoc network. The terminal MR (for example, MR7) located is notified.

Next, the operation of the intermediate MR when information on establishment of a detour route is notified from the adjacent MR will be described with reference to the explanatory diagram of FIG.
In FIG. 13, the wireless information notification (establishment of a bypass route) notified from the adjacent MR is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 to the wireless state management unit 4, and the wireless state management unit 4 includes an ad hoc route control unit. 5, the wireless information notification (establishment of a bypass route) is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 to the terminal MR (MR 7).

FIG. 14 is a flowchart showing the operation of each MR that establishes a detour path. The same processes as those described above (see FIGS. 5 and 7) are denoted by the same reference numerals and detailed description thereof is omitted.
In FIG. 14, first, when the completion of route establishment by route control is detected within the MR (step S21), the route information is referred to (step S2) in the same manner as described above, and the position of the own device on the route is determined. (Step S3).

Thereafter, if it is determined in step S3 that the device is in the middle of the route, a wireless information notification (establishment of a detour route) is transmitted upstream of the route (step S24), and the processing in FIG.
On the other hand, if it is determined in step S3 that the own device is the end of the route, a route information collection message is transmitted downstream in the route (step S25), and the processing in FIG. 14 is terminated.
Step S25 relates to the sixth embodiment described later.

  The feature of the third embodiment of the present invention corresponds to the operation in step S24 when the MR determines that “the position on the route of its own device is in the middle of the route” in the processing flow (step S3) of FIG. To do.

FIG. 15 is a flowchart showing the operation of each MR when a wireless information notification (establishment of a bypass route) is received. The step S21 in FIG. 14 is omitted, and “establishment of route” after the bypass route is established. The transmission point (step S24 ′) is different.
The feature of the third embodiment of the present invention corresponds to the operation of step S24 when the MR determines that “the position on the route of its own device is in the middle of the route” in the processing flow of FIG. 15 (step S3). To do.

  As described above, the intermediate mobile routers (MR2, MR3, MR5) of the mobile router ad hoc network communication system according to Embodiment 3 (FIGS. 11 to 15) of the present invention are the terminal mobile routers (MR1, MR7), When the TCP Proxy processing is executed for the first to third TCP data packets received from the IP terminals (MNN1, MNN7) and transmitted to the ad hoc network, the route to the mobile router located at the next hop is not available. Includes information indicating the start of a search for a detour route via another mobile router (MR4) that detours a route in an unusable section, and information indicating the completion of establishment of the detour route via a route of the ad hoc network. Addressed to mobile routers (MR1, MR7) located in the direction opposite to the direction of transmission To send.

  Further, when the intermediate mobile router (MR2, MR3, MR5) receives a packet for notifying an ad hoc route control processing start event and a new ad hoc route control processing route establishment event from an adjacent mobile router, Forward to the next-hop mobile router according to the route of the ad hoc network.

  As a result, the fourth function of the terminal mobile router (MR1, MR7) is configured to send an ad hoc route control process start event in the middle of a communication route and a route establishment event by a new ad hoc route control process to an intermediate mobile router ( MR2, MR3, MR5), and when the first to third TCP data packets are transferred to the next-hop mobile router, the communication path is determined by using the ad hoc path control state information on the communication path. It is determined whether or not the first to third TCP data packets scheduled to be transmitted are transmitted.

  The fourth function of the terminal mobile router (MR1, MR7) is to temporarily transmit the first to third TCP data packets when the communication path is temporarily disconnected according to the determination result. Stop unnecessary retransmission control.

  Further, the fourth function of the terminal mobile routers (MR1, MR7) is that wireless signals obtained from a plurality of intermediate mobile routers on the communication path are obtained when the communication path is established based on the determination result of whether or not transmission is possible. The transmission rates of the first to third TCP data packets are limited so as to be within the transmission possible rate in the communication path recognized from the transmission band information.

In this way, a mobile router ad hoc network communication system that realizes efficient TCP packet transfer can be obtained by establishing a detour path when the wireless link cannot be recovered.
Further, similarly to the above, it is possible to suppress the TCP congestion control from being excessively operated by the TCP connection, and to suppress a decrease in throughput in the TCP data communication due to the excessive TCP congestion control.

Embodiment 4 FIG.
In the third embodiment (FIGS. 11 to 15), the detour path is established in the middle of the path (MR2 and MR3 where the radio link is broken). However, as shown in FIG. (MR1, MR7) may try to establish a new route.
Hereinafter, a fourth embodiment of the present invention in which a new route is established in the route terminals MR1 and MR7 will be described with reference to FIGS.

FIG. 16 is a perspective view for explaining the operation of the fourth embodiment of the present invention. When a failure occurs in the intermediate MR on the communication path, a new path is established at the terminal MR (MR1, MR7) at the path end point. An example of operation when trying (before establishing an alternative route) is shown.
FIG. 17 is a perspective view for explaining the operation at the time of establishing an alternative route (solid double-pointed arrow). The same parts as those described above (see FIG. 11) are denoted by the same reference numerals as those described above and described in detail. Is omitted.

  Further, FIG. 18 is an explanatory diagram showing the operation of the intermediate MR according to the fourth embodiment of the present invention with a thick arrow in the block diagram. When the path disconnection with the adjacent MR is detected and the path control is started. The transmission operation of the wireless information notification is shown. In FIG. 18, the same components as those described above (see FIGS. 12 and 13) are denoted by the same reference numerals as those described above, and detailed description thereof is omitted.

  First, in FIG. 16, a radio link between MRs (MR2-MR3, MR3-MR4, MR3-MR5) due to a failure of a radio device at a location (for example, intermediate MR3) that has been responsible for relaying in the communication path. MR5 and MR2 that have detected “wireless link disconnection” notify MR1 and MR7, which are the end points of the TCPProxy section, of the start of ad hoc path control processing, and the adjacent MR3 and MR3. Attempts to restore the wireless link and establish a detour route.

However, if neither the restoration of the radio link nor the establishment of the detour route has succeeded, the route terminals MR1 and MR7 perform ad hoc route control processing (see FIG. 17).
At this time, MR1 and MR7 suspend the TCP packet transfer in the TCP connection that is the target of the TCPProxy processing, and resume the TCP packet transfer after the establishment of a new route is completed.

  At this time, the new MR4 and MR6 in the middle of the path (mobile routers on the path that do not accommodate IP terminals) detect a path disconnection with an adjacent mobile router as shown in FIG. 18, and perform ad hoc path control. Start.

  That is, as shown in FIG. 18, when it is determined by ad hoc route control of the mobile router that packet transfer is not possible on the route with the adjacent MR, the ad hoc route control unit 5 changes to the radio state management unit 4. The start of ad hoc route control is notified (see bold arrows).

  Subsequently, upon receiving the ad hoc route control start notification from the ad hoc route control unit 5, the wireless state management unit 4 establishes a bypass route in the ad hoc network between the mobile routers by wireless information notification (ad hoc route control start). The terminal MR (MR1, MR7) located at the end point of the route of the ad hoc network is notified that the packet transfer is temporarily impossible because the trial has started (see thick arrows).

  FIG. 19 is a flowchart showing the operation of each MR at the time of receiving the wireless information notification (route control start) according to the fourth embodiment of the present invention. The same processing as that described above (see FIG. 5) is the same as that described above. The detailed description is omitted.

The operation at the time of starting ad hoc route control by the intermediate MR on the communication route is performed when the MR determines that the position on the route of the own device is in the middle of the route in the processing flow of FIG. 19 (step S3). This corresponds to the operation (step S34).
Further, the operation at the time of starting ad hoc route control in the terminal MR is the operation when the MR determines that “the position on its own route is the route end” in the processing flow (step S3) of FIG. 19 (step S35). ).

  In FIG. 19, first, when the start of route control is detected in the own device or when wireless information notification (route control start) is received from upstream of the route (step S31), the route information is referred to in the same manner as described above. (Step S2), the position of the own device on the route is determined (Step S3).

  If it is determined in step S3 that the position of the own device on the route is “route intermediate”, a wireless information notification (route control start) is transmitted downstream of the route (step S34), and the processing of FIG. To wait for the next process.

  On the other hand, if it is determined in step S3 that the position of the own device on the route is “route end”, the TCP packet transfer from the MNN to the ad hoc network is temporarily stopped (step S5), and the next processing waiting state is established. It becomes.

At this time, after receiving the wireless information notification (ad hoc route control start), the terminal MR at the route endpoint accommodating the IP terminal performs a new ad hoc route control if the detour route is not established within a predetermined time. Start.
In addition, when a new alternative route is established at the terminal MR which is the route end point, collection of route information in the alternative route is started. The operation at the time of detecting the route establishment in the terminal MR at this time corresponds to the operation in step S25 in FIG.

  In addition, if the establishment of the alternative route is not completed within a predetermined time specified in advance and the terminal MR gives up the ad hoc route control, the terminal MR notifies the subordinate IP terminal (MNN) of the reset of the TCP connection. These TCP connections are removed from the TCP Proxy processing target.

FIG. 20 is an explanatory diagram showing the operation at the time of resetting the TCP connection according to the fourth embodiment of the present invention, and shows that the terminal MR has not established an alternative route with the other (far-end) terminal MR. The operation in the case of detection is indicated by a thick line arrow in the block diagram.
In FIG. 20, when abandoning the ad hoc route control, first, a route deletion notification is transmitted from the ad hoc route control unit 5 to the wireless state management unit 4.

As a result, the wireless state management unit 4 instructs the TCP flow determination / TCP packet transfer processing unit 1 to end the transfer of the packet addressed to the ad hoc network port.
Finally, the TCP flow determination / TCP packet transfer processing unit 1 transmits a TCP flow reset between the MNN and the ad hoc network to the local port transmission / reception processing unit 3 for MNN.

FIG. 21 is a flowchart showing the operation of each MR at the time of resetting the TCP connection, and shows the operation when a route deletion by ad hoc route control is detected inside the MR.
In FIG. 21, when a route is deleted, TCP reset transmission to the MNN is performed, and the TCP flow from the MNN to the ad hoc network is reset (step S40).

  As described above, according to the mobile router ad hoc network communication system according to the fourth embodiment (FIGS. 16 to 21) of the present invention, the fourth function of the terminal mobile router (MR1, MR7) , When executing the TCP Proxy process on the first to third TCP data packets received from the IP terminals (MNN1, MNN7) and transmitted to the ad hoc network, the ad hoc path control process start state in the middle of the communication path, Alternatively, it is acquired from the intermediate mobile router that any wireless connection state between the plurality of mobile routers is temporarily disconnected or the wireless transmission band is zero.

  Subsequently, the fourth function of the terminal mobile router (MR1, MR7) is that the route state and radio state on the communication route used when the first to third TCP data packets are transferred to the next-hop mobile router. The communication path in the ad hoc network is temporarily disconnected based on the result of determining whether the first to third TCP data packets scheduled to be transmitted via the communication path of the ad hoc network are used. In the state where unnecessary retransmission control is suppressed and the ad hoc route control function of the terminal mobile router that is the end point of the communication route between each IP terminal is given up waiting for the restoration of the communication route. Starts the route search process to form a new alternative route, and temporarily stops when it detects that a new alternative route has been generated. Resume the transfer of the first through third TCP data packets.

  Thereby, even if a detour route cannot be established when a failure occurs in the intermediate MR, an alternative route can be established in the terminal MR, and the same operational effects as described above can be achieved.

In addition, the fourth function of the terminal mobile router according to the fourth embodiment of the present invention is that, even if a predetermined time elapses after the route search process is attempted to form a new alternative route by the ad hoc route control function. When it is detected that a new alternative route could not be generated, the first to third TCP connection IP terminals that temporarily stopped the transfer of the first to third TCP data packets are Execute reset of the third TCP connection.
As a result, the TCP connection can be disconnected when the path cannot be established.

Embodiment 5 FIG.
In the first to fourth embodiments (FIGS. 1 to 21), the case where the radio band is changed is not mentioned, but when the band change occurs in the intermediate MR, as shown in FIG. “Bandwidth change” may be transmitted to the terminal MR as a wireless information notification.
The fifth embodiment of the present invention corresponding to the band change will be described below with reference to FIGS. In addition, in each figure, about the thing similar to the above, the same code | symbol as the above is attached | subjected and detailed description is abbreviate | omitted.

FIG. 22 is a perspective view for explaining the operation of the fifth embodiment of the present invention and shows an operation example when the band of the radio link between MR2 and MR3 in the communication path is changed.
FIG. 23 is an explanatory diagram showing the operation of the intermediate MR according to the fifth embodiment of the present invention, and the operation when a radio information notification (band change) is received from the radio apparatus or the adjacent MR is indicated by a thick arrow. . Further, FIG. 24 is a flowchart showing the operation of each MR when the transmission band is changed by the radio link.

  In FIG. 22, when the transmittable band from MR2 to MR3 is changed, the intermediate MR2 that has detected the band change transmits a wireless information notification (band change) to the terminal MR1 that is the end point of one TCP Proxy section. Thus, the fact that the transmission band from MR2 to MR3 has been changed is notified.

Similarly, intermediate MR 3 notifies terminal MR 7 that the transmission band from MR 3 to MR 2 has been changed.
MR1 and MR7 (endpoints of the TCP proxy section) that have received the wireless information notification (bandwidth change) execute a maximum bandwidth change process in the TCP packet transfer between MR1 and MR7, and excessive TCP packets into the ad hoc network Prevent transmission.

  Next, with reference to FIG. 23, the operation when the band change is notified from the wireless device in the intermediate MR at this time (the mobile router located in the middle of the ad hoc route and not accommodating the IP terminal) will be described.

In FIG. 23, the wireless information notification (band change) notified from the wireless device to the mobile router is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 to the wireless state management unit 4, and the wireless state management unit 4 With reference to the route information held by the control unit 5, the wireless information notification (band change) is transferred to the mobile router (MR1 or MR7) at the route end point.
The operation when the band change is notified from the adjacent MR among the intermediate MRs is the same.

Next, the operation of each MR when the transmission band is changed by the radio link will be described with reference to the flowchart of FIG.
In FIG. 24, when MR receives a wireless information notification (bandwidth change) from the wireless device or upstream of the route (step S51), the MR refers to the route information (step S2) and determines the position of the own device on the route (step S51). S3).

If it is determined in step S3 that the own apparatus is an intermediate MR in the middle of the path, a wireless information notification (band change) is transmitted downstream in the path (step S54), and the process in FIG. 24 is terminated.
If it is determined that the own device is the terminal MR at the end of the route, a route information collection message is transmitted toward the route upstream (step S55), and the processing in FIG. 24 is terminated.

The operation when the band change is detected in the mobile routers (MR2, MR3, MR5) in the middle of the path is as follows. In the processing flow (step S3) in FIG. This corresponds to the operation when it is determined that “is” (step S54).
Also, in the mobile router in the middle of the route, when the wireless information notification (bandwidth change) is received from the adjacent mobile router, the MR is “position on the route of the own device” in the processing flow (step S3) of FIG. Corresponds to the operation when it is determined that “is in the middle of the path”.

  Furthermore, when the mobile router (MR1, MR7) at the path end point receives the wireless information notification (band change) from the adjacent mobile router, the operation is performed by the MR in the processing flow (step S3) in FIG. Corresponds to the operation (step S55) when it is determined that the position on the route is the end of the route.

  As described above, the mobile routers (MR1, MR7) of the mobile router ad hoc network communication system according to the fifth embodiment (FIGS. 22 to 24) of the present invention receive the ad hoc from the IP terminals (MNN1, MNN7). A route information collection message for investigating wireless transmission band information of a communication route between IP terminals in an ad hoc network from a terminal mobile router when performing TCPProxy processing on the first to third TCP data packets transmitted to the network Is transmitted to the communication terminal mobile router (MR7, MR1).

  The intermediate mobile routers (MR2, MR3, MR5) add the wireless transmission band information for transmission toward the downstream of the communication path to the path information collection message received from the upstream of the communication path, and then the communication path To the downstream mobile router.

  The terminal mobile router (MR7, MR1) of the communication partner returns the path information collection message received from the upstream of the communication path as a path information notification message to the terminal mobile router (MR1, MR7) of the transmission source, and the intermediate mobile router (MR2, MR3, MR5) transfers the route information notification message received from the downstream of the communication route to the mobile router upstream of the communication route.

  Also, the terminal mobile router (MR1, MR7) that transmitted the original route information collection message receives the route information notification message from the downstream of the communication route, so that wireless transmissions obtained from a plurality of mobile routers on the communication route are obtained. The transmission rates of the first to third TCP data packets are limited so as to be within the maximum transmittable rate recognized from the band information.

As a result, the TCP Proxy process adapted to the wireless state can be executed as described above.
In addition, when TCP communication is performed between IP terminals in an ad hoc network where a plurality of mobile routers are interconnected using a wireless system, a decrease in throughput due to excessive TCP congestion control in the TCP connection is suppressed. can do.

Embodiment 6 FIG.
In the first to fifth embodiments, route information is always collected as described above.
Hereinafter, route information collection according to the sixth embodiment of the present invention will be described in detail with reference to FIGS. In addition, in each figure, the same code | symbol as the above-mentioned is attached | subjected about the same thing as the above-mentioned.

  For example, in the third and fourth embodiments described above, between ad hoc network route terminal mobile routers (MR1, MR7) by ad hoc route control processing such as establishment of a detour route or establishment of a new alternative route. When the TCP Proxy section is established, it is necessary to confirm the TCP packet continuity in the TCP Proxy section and to recognize that each intermediate MR in the middle of the route is located in the middle of the TCP Proxy section.

  Further, in the above-described fifth embodiment, the terminal mobile router which is the end point of the ad hoc network changes the maximum transmission band to the TCP Proxy section by the band change processing of any one of the radio sections constituting the ad hoc network path. When it is recognized that there is a possibility, the MR that is the end point of the TCP Proxy section needs to recognize the maximum transmittable bandwidth value on the route in the ad hoc network.

  If it is recognized that there is a possibility that the section that is the minimum band in the TCP Proxy section in the path has been changed due to the change in the communication path, the maximum transmittable bandwidth value in the path in the ad hoc network Must be recognized by the terminal MR, which is the end point of the TCPProxy section.

  Therefore, in order to satisfy the above request, one terminal MR1 that is the end point of the TCP Proxy section that has been determined that the wireless information in the route of the TCP Proxy section may have been changed, is directed toward the terminal MR7 that is the other end point. A section route information collection message is transmitted.

FIG. 25 is a perspective view for explaining a TCP Proxy section for collecting route information. The same reference numerals as those described above are assigned to the same components as described above.
In this case, the route information collection message is transmitted as route information to the MR of the next hop by adding the transmission transmission band of the radio link from the own MR to the MR of the next hop in association with the identifier of the own MR. .

  In FIG. 25, the terminal MR (for example, MR1) that is the end point of the TCP Proxy section transmits the “TCPProxy section path information collection” message received from the terminal MR (for example, MR7) at the opposite end point to the source MR (for example, Return to MR7).

  At this time, the terminal MR (mobile router that accommodates an IP terminal, which is a route endpoint) receives a wireless information notification (establishment of a detour route) from an intermediate mobile router located in the middle of the route, and executes route information collection.

Hereinafter, the route information collection operation by the terminal MR will be described with reference to the explanatory diagram of FIG.
In FIG. 26, the wireless information notification (establishment of a bypass route) notified from the adjacent MR located in the middle of the route is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 to the wireless state management unit 4.

  Subsequently, when the wireless state management unit 4 refers to the route information held by the ad hoc route control unit 5 and recognizes that the bypass route has been established by the wireless information notification (establishment of the bypass route), transmission on the new bypass route is performed. In order to know the possible bandwidth, a route information collection message is transmitted to the terminal MR located at the other route end point.

The operation of the terminal MR at this time is shown in step S25 in the flowchart of FIG.
The feature of the sixth embodiment of the present invention corresponds to the operation (step S25) when the MR determines that “the position of the own device on the path is the path end” in the processing flow (step S3) of FIG. To do.

  FIG. 27 is an explanatory diagram showing the operation of the terminal MR when establishing a new route and collecting route information. By ad-hoc route control at the terminal MR (mobile router that is a route endpoint that accommodates an IP terminal). The operation when a new route is established is shown.

  In FIG. 27, the radio information management unit 4 in the terminal MR, which has been notified that “a new route has been established” by the ad hoc route process, sends a route information collection message in order to recognize the transmittable bandwidth in the new route. Transmission is performed toward the other terminal MR (mobile router located at the route end point).

The operation of the terminal MR at this time is shown in step S25 in the flowchart described above (FIG. 14).
That is, the sixth embodiment of the present invention is characterized in that the operation when the MR determines that “the position of its own device on the path is the path end” in the processing flow (step S3) of FIG. 14 (step S25). It corresponds to.

  On the other hand, FIG. 28 is an explanatory diagram showing the operation of an intermediate MR (mobile router that does not accommodate an IP terminal and is in the middle of a route), and shows the operation when a route information collection message is received from an adjacent MR.

In FIG. 28, the route information collection message notified from the adjacent MR is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 to the radio state management unit 4.
The radio state management unit 4 refers to the route information held by the ad hoc route control unit 5 and adds the radio information to the route information collection message, and is directed to the terminal MR (mobile router located at the route end point of the ad hoc network). Send a route information collection message.

The operation of the intermediate MR at this time is shown in step S64 in the flowchart of FIG.
That is, the sixth embodiment of the present invention is characterized in that the operation when the MR determines that “the position of its own device on the route is in the middle of the route” in the processing flow (step S3) of FIG. 29 (step S64). It corresponds to.

  In the processing flow when the “route information collection message” is received in FIG. 29, the intermediate MR first receives a route information collection message from the downstream of the communication route (step S61), refers to the route information (step S2), The position of the own device on the route is determined (step S3).

If it is determined in step S3 that “the position of the own device on the route is in the middle of the route”, the wireless link information in the upstream direction of the route is added to the route information collection message and transmitted toward the upstream side of the route. (Step S64), the process of FIG. 29 is terminated.
On the other hand, if it is determined in step S3 that "the position of the own device on the route is the route end", the information of the route information collection message is sent to the end point (terminal MR) downstream of the route as a route information notification message. This is transmitted (step S65), and the process of FIG. 29 is terminated.

FIG. 30 is an explanatory diagram showing the operation of the terminal MR (mobile router that accommodates an IP terminal, which is a route endpoint), and shows the operation when a route information collection message is received.
In FIG. 30, the route information collection message notified from the adjacent MR is transferred from the inter-MR ad hoc network port transmission / reception processing unit 3 in the terminal MR to the radio state management unit 4.

  The radio state management unit 4 refers to the route information held by the ad hoc route control unit 5 and is directed to the terminal MR located at the other route end point of the ad hoc network that is the transmission source of the received route information collection message. A route information collection message is transmitted as a “route information notification message”.

The operation of the terminal MR at this time corresponds to the operation (step S65) when the MR determines that “the position on the route of its own device is the route end” in the processing flow of FIG. 29 (step S3).
The route information notification message from the terminal MR is transferred in the intermediate mobile router in the same way as the route information collection message transfer process shown in FIG.

Next, the operation of each MR when receiving the route information notification message will be described with reference to the flowchart of FIG.
The feature of the sixth embodiment of the present invention corresponds to the operation when the MR determines that “the position on its own route is in the middle of the route” in the operation flow (step S3) of FIG.

  In FIG. 31, first, when the MR receives a route information notification message from the upstream of the communication route (step S71), referring to the route information (step S2), the position of the own device on the route is determined (step S3). .

If it is determined in step S3 that “the position on the route of the own device is in the middle of the route”, a route information notification message is transmitted downstream in the route (step S74), and the processing in FIG. 31 is terminated.
On the other hand, if it is determined in step S3 that “the position of the own device on the route is the route end”, the route information is updated, and the TCP packet transfer rate from the MNN (IP terminal) to the ad hoc network is changed. (Step S75), the process of FIG. 31 is terminated.

FIG. 32 is an explanatory diagram showing the operation of the terminal MR (mobile router serving as a route endpoint that accommodates an IP terminal) when a route information notification message is received.
In the terminal MR, when a route information notification message arrives as a response to the route information collection message transmitted from its own device, the route information notification message notified from the adjacent MR is transmitted from the inter-MR ad hoc network port transmission / reception processing unit 3 to the It is transferred to the state management unit 4.

  Subsequently, the wireless state management unit 4 determines an appropriate transmission band in this communication path, and instructs the TCP flow determination / TCP packet transfer processing unit 1 to resume transfer of the TCP packet addressed to the ad hoc network port.

As a result, the TCP flow determination / TCP packet transfer processing unit 1 resumes the transfer of packets between ad hoc networks within the designated transmission band in accordance with the instruction from the wireless state management unit 4.
The operation of the terminal MR at this time corresponds to the operation (step S75) when the MR determines that “the position on its own route is the route end” in the processing flow of FIG. 31 (step S3).

  As described above, according to the sixth embodiment of the present invention, it is possible to achieve the operational effects as described in the first to fifth embodiments by collecting the route information.

  1 TCP flow determination / TCP packet transfer processing unit, 2 MNN local port transmission / reception processing unit, 3 MR ad hoc network port transmission / reception processing unit, 4 radio state management unit, 5 ad hoc route control unit, 6 IP packet processing unit, MR1, MR7 Terminal mobile router, MR2 to MR6 Intermediate mobile router, MR2, MR3, MR5 Intermediate mobile router constituting a TCP Proxy section, MR4, MR6 Intermediate mobile router constituting a bypass route or an alternative route.

Claims (6)

A plurality of mobile routers connected to each other by a wireless system to form an ad hoc network;
An IP terminal accommodated under each terminal mobile router located at both ends of the communication path of the ad hoc network,
A mobile router ad hoc network communication system for realizing IP communication between IP terminals of each terminal mobile router,
Each of the plurality of mobile routers includes a TCP Proxy function for performing TCP congestion control and TCP retransmission control,
The TCP proxy function of the terminal mobile router includes first and second functions,
The TCP Proxy function of the intermediate mobile router located in the middle of the communication path includes a third function,
The first function of the terminal mobile router is:
Recognizing a first TCP connection of a first TCP data packet received from the IP terminal, and determining whether the first TCP connection is to be a TCP Proxy processing target;
When the first TCP connection is the TCP Proxy processing target, a TCP ACK packet for the first TCP data packet is sent to a destination IP terminal among the IP terminals that are destinations of the first TCP data packet. Instead, return the first TCP data packet to the first source IP terminal,
The first TCP data packet received from the first source IP terminal is forwarded to a mobile router that is the next hop determined by ad hoc route control of the ad hoc network, and the transferred TCP data packet is temporarily stored. And
Responding to the TCP data packet retransmission request from the TCP proxy function of the destination IP terminal or the mobile router accommodating the destination IP terminal, the transferred TCP data packet temporarily stored is retransmitted on behalf of the IP terminal. ,
The second function of the terminal mobile router is:
Recognizing the second TCP connection of the second TCP data packet addressed to the IP terminal received from the adjacent mobile router of the terminal mobile router, whether or not the second TCP connection should be the target of the TCP proxy processing Determine whether
When the second TCP connection is the TCP Proxy processing target, the second TCP data packet is temporarily stored, and the TCP sequence number stored in the second TCP data packet is used. Check the order of the temporarily stored second TCP data packet, and send the second TCP data packet to the IP terminal in the correct order;
If the second TCP data packet is missing based on the inspection result by the TCP sequence number, the missing second address is sent to the second source IP terminal of the second TCP connection. Request retransmission of the TCP data packet,
The third function of the intermediate mobile router is:
Recognizing a third TCP connection of a third TCP data packet received from an adjacent mobile router of the intermediate mobile router and addressed to an IP terminal accommodated by another mobile router, the third TCP connection is subjected to TCP Proxy relay processing. Determine if it should be the target,
When the third TCP connection is the TCP Proxy relay processing target, the received third TCP data packet is forwarded to the next-hop mobile router.
In a mobile router ad hoc network communication system,
The TCP proxy function of the terminal mobile router further includes a fourth function,
The fourth function of the terminal mobile router is:
When executing the TCPProxy process on the first to third TCP data packets received from the IP terminal and transmitted to the ad hoc network,
From a wireless device that performs wireless connection with an adjacent mobile router directly connected to the terminal mobile router, obtain a wireless connection state or wireless transmission band information between the adjacent mobile router,
Based on the wireless connection state or wireless transmission band information of a wireless line used when transferring the first to third TCP data packets to the next-hop mobile router, the next hop is transmitted via a wireless device. To determine whether or not to transmit the first to third TCP data packets scheduled to be transmitted to the mobile router,
When any of the wireless connection states between the plurality of mobile routers interconnected in the ad hoc network is temporarily disconnected, or when any of the wireless transmission bands is zero, the first to first Suppressing unnecessary retransmission control by temporarily stopping transmission of the third TCP data packet,
When the wireless connection state between the plurality of mobile routers is a connection state and the wireless transmission band is not zero, the transmission rate is recognized within the transmittable rate recognized from the wireless transmission band information obtained from the wireless device. Limiting the transmission rate of the first to third TCP data packets;
A mobile router ad hoc network communication system. The intermediate mobile router is
When the terminal mobile router performs the TCP Proxy process on the first to third TCP data packets received from the IP terminal and transmitted to the ad hoc network,
The wireless connection state or the wireless transmission band information in the wireless device directly connected to the intermediate mobile router is positioned in a path direction opposite to the direction in which the wireless route is transmitted via the wireless device of the intermediate mobile router in the communication path. To the terminal mobile router
When receiving a packet for notifying the wireless connection state or the wireless transmission band information from the adjacent mobile router, according to the communication path, forward to the mobile router of the next hop,
The fourth function of the terminal mobile router is:
The wireless connection state or the wireless transmission band information in a wireless device directly connected to the intermediate mobile router is acquired from the intermediate mobile router,
When the first to third TCP data packets are transferred to the next-hop mobile router, the communication path is used by using wireless connection states or wireless transmission band information in a plurality of wireless devices on the communication path. Determining whether or not to transmit the first to third TCP data packets scheduled to be transmitted via
If any wireless connection state between the plurality of mobile routers is temporarily disconnected, or if any wireless transmission band is zero, the first to third TCP data packets Suppress unnecessary retransmission control by temporarily stopping transmission,
When the wireless connection state between the mobile routers constituting the communication path is a connection state, the transmittable rate in the communication path recognized from the wireless transmission band information obtained from a plurality of mobile routers on the communication path Limiting the transmission rate of the first to third TCP data packets so that
The mobile router ad hoc network communication system according to claim 1. The intermediate mobile router is
When the terminal mobile router performs the TCPProxy process on the first to third TCP data packets received from the IP terminal and transmitted to the ad hoc network,
If the route to the mobile router located at the next hop cannot be used, information indicating the start of searching for a detour route via another mobile router that detours the route of the unusable section, and completion of establishment of the detour route To the terminal mobile router located in the path direction opposite to the direction to transmit via the path of the ad hoc network,
When a packet for notifying the ad hoc route control processing start event and a new ad hoc route control processing route establishment event is received from the adjacent mobile router, it is sent to the next hop mobile router according to the ad hoc network route. Forward,
The fourth function of the terminal mobile router is:
An ad hoc route control process start event in the middle of the communication path and a route establishment event by a new ad hoc route control process are acquired from the intermediate mobile router,
When transferring the first to third TCP data packets addressed to the next-hop mobile router, the ad hoc route control state information on the communication route is used to schedule transmission via the communication route. Determining whether or not the first to third TCP data packets are transmitted,
When the communication path is temporarily disconnected, the unnecessary retransmission control is suppressed by temporarily stopping the transmission of the first to third TCP data packets,
When the communication path is in an established state, the first and second transmission rates are recognized so as to be within the transmittable rate in the communication path, recognized from radio transmission band information obtained from a plurality of intermediate mobile routers on the communication path. Limit the transmission rate of the first to third TCP data packets;
The mobile router ad hoc network communication system according to claim 1 or 2, characterized by the above. The fourth function of the terminal mobile router is:
When the terminal mobile router performs the TCPProxy process on the first to third TCP data packets received from the IP terminal and transmitted to the ad hoc network,
The ad hoc route control processing start state in the middle of the communication route, or any wireless connection state between the plurality of mobile routers is temporarily disconnected, or the wireless transmission band is zero From the intermediate mobile router,
Via the communication path of the ad hoc network, using the information of the path state and the radio state on the communication path used when transferring the first to third TCP data packets to the mobile router of the next hop Based on the result of determining whether or not to transmit the first to third TCP data packets scheduled to be transmitted, it is determined that the communication path in the ad hoc network is temporarily disconnected, and unnecessary retransmission control is suppressed. In the state that
By the ad hoc route control function of the terminal mobile router that is the end point of the communication route between the IP terminals, a route search process is started to form a new alternative route,
When detecting that the new alternative route is generated, the transfer of the first to third TCP data packets that have been temporarily stopped is resumed.
The mobile router ad hoc network communication system according to any one of claims 1 to 3, wherein the mobile router ad hoc network communication system is provided. The fourth function of the terminal mobile router is:
When the ad hoc route control function detects that the new alternative route could not be generated even after a predetermined time has elapsed since the route search process was attempted to configure the new alternative route, Resetting the first to third TCP connections to the IP terminals of the first to third TCP connections that have stopped transferring the first to third TCP data packets;
The mobile router ad hoc network communication system according to claim 4. The terminal mobile router is
When executing the TCPProxy process on the first to third TCP data packets received from the IP terminal and transmitted to the ad hoc network,
A route information collection message for investigating wireless transmission band information of a communication route between the IP terminals in the ad hoc network is transmitted from the terminal mobile router to the communication partner terminal mobile router,
The intermediate mobile router adds wireless transmission band information when transmitting toward the downstream of the communication path to the path information collection message received from the upstream of the communication path, and then downstream of the communication path. To the mobile router
The communication terminal mobile router is:
The route information collection message received from the upstream of the communication route is sent back as a route information notification message to the terminal mobile router of the transmission source,
The intermediate mobile router forwards the route information notification message received from the downstream of the communication route to the mobile router upstream of the communication route,
The terminal mobile router that sent the original route information collection message
By receiving a route information notification message from downstream of the communication route, the first to first rates are set so as to be within the maximum transmittable rate recognized from the wireless transmission band information obtained from a plurality of mobile routers on the communication route. Limit the transmission rate of the third TCP data packet;
The mobile router ad hoc network communication system according to any one of claims 1 to 5, wherein the mobile router ad hoc network communication system is provided.

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