JP2010226668A - Communication device and method of controlling traffic volume - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device that prevents a controlled mobile network node from determining that a network is congested when a communication band is varied. <P>SOLUTION: The communication device that operates as a mobile router includes: a statistical information management portion 13 that collects the current position, moving speed, and type of communication media in use of its own device, radio field intensity, communication speed and network delay between counter devices and holds them as the statistical information; a moving plan management portion 14 for estimating variation of the communication band caused by the movement of the own device based on the statistical information held by the statistical information management portion 13; and a TCP proxy function portion 11 for controlling the user traffic volume that is transmitted from an IP terminal accommodated therein based on the estimated results of the variation at the moving plan management portion 14. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a communication apparatus that operates as a mobile router or a home agent of a communication system that realizes network mobility using mobile IP (Internet Protocol), and a traffic amount control method.

  TCP (Transmission Control Protocol) is used for the transport layer in IP communication that requires certainty, such as WEB browsing or downloading on the Internet. In TCP, when a packet receiving terminal normally receives a packet, it returns an acknowledgment packet to the transmitting terminal. By receiving this confirmation response, the transmission side terminal transmits the next packet, and when the confirmation response does not come, it retransmits the same packet, thereby maintaining the certainty of data transfer. In TCP, efficient data transfer is realized using a technique called window control. In this window control, when the amount of packets that can be sent without an acknowledgment (called window size) is reached, the sending terminal continues to send packets without waiting for an acknowledgment, and the receiving terminal reaches the window size. In the same way, a confirmation response packet is returned. Congestion control is performed by changing the window size according to the network status.

  Patent Document 1 below describes an example of an IP communication system using TCP. In the system described in Patent Document 1, a TCP proxy device is arranged in the vicinity of a terminal, and each TCP proxy device performs high-speed data transfer in a method that does not depend on the connection distance, thereby increasing the connection distance that is a problem of TCP. As a result, the data transfer speed is prevented from decreasing.

  In addition, as another technique related to IP communication, Mobile IP (Mobile IP) that allows communication to continue even when a wireless terminal in IP communication moves between connection points is defined in Non-Patent Documents 1 and 2 below. ing.

  When this mobile IP is applied, when a mobile IP terminal (Mobile Node, hereinafter referred to as MN) moves to an external network (Foreign Network) other than the home link, the subnetwork prefix of the external network is transferred to the network. By registering a Care-of Address (hereinafter referred to as “CoA”) as an identifier with a Home Agent (hereinafter referred to as “HA”), the MN can obtain a home address (hereinafter referred to as “HoA”) that is an IP address assigned to itself. It is possible to continue communication with a communication partner (Correspond Node, hereinafter referred to as CN) without changing the description.

  Further, in a system in which the router accommodating the MN performs wireless connection with an access router that is a higher-level communication device, the router maintains an IP router while maintaining an IP communication (Access Router, hereinafter referred to as AR). Non-Patent Documents 3 and 4 below define NEMO Basic Support Protocol (hereinafter simply referred to as NEMO) that enables switching operation.

  In NEMO, a router (Mobile Router, hereinafter referred to as MR) that accommodates a plurality of subnets under its control has a function equivalent to that of a mobile IP MN, thereby realizing network mobility of the IP subnet itself. In NEMO, an extension is added to add a subnetwork (Mobile Network Prefix, hereinafter referred to as MNP) accommodated by MR to Binding Update (hereinafter referred to as BU) which is a location registration message of Mobile IP. As a result, an IP terminal (Mobile Network Node, hereinafter referred to as MNN) belonging to the MNP can communicate without performing signaling such as location registration even when the MR moves and changes the AR of the connection point. It is possible to continue. User traffic between the MNN and the CN is IP-in-IP encapsulated and transferred by the MIP tunnel between the MR and HA.

JP 2005-136684 A

IETF (Internet Engineering Task Force) RFC3344 “IP Mobility Support for IPv4” IETF RFC3775 “Mobility Support in IPv6” IETF RFC3963 “Network Mobility (NEMO) Basic Support Protocol” IETF RFC5177 “Network Mobility (NEMO) Extensions for Mobile IPv4”

  However, the technology described in Patent Document 1 does not take into account the mobility of an IP terminal or a router that accommodates the IP terminal as described in Non-Patent Documents 1 to 4 above. Therefore, when the technique (TCP proxy function) described in Patent Document 1 is applied to a system including an MR, the MR and the MNN accommodated in the MR (hereinafter collectively referred to as “mobile”) However, due to temporary communication interruption at the time of handover and fluctuations in the communication band accompanying handover or movement of the mobile body, a situation in which transfer between TCP proxies cannot be performed successfully occurs. In addition, when the communication band becomes narrow due to handover, etc., it is necessary to suppress the amount of user traffic (amount of user data transmitted and received) between the MNN and the CN, and output from the MNN until the amount of user traffic decreases. It is necessary to temporarily buffer the received user data by the MR having the TCP proxy function or the TCP proxy function (apparatus) independent of the MR. This means that if the buffer amount of the TCP proxy function is small, user data cannot be stored and data discarding occurs.

  Therefore, when the communication between the MNN and the CN is made efficient by the TCP proxy function, if the user traffic volume is controlled while measuring the communication band with movement, the communication terminal cannot follow the rapid change of the communication band. May determine network congestion.

  The present invention has been made in view of the above, and avoids the IP terminal from determining that the network is congested and reducing the window size even when the communication band suddenly fluctuates with movement. It is an object of the present invention to obtain a communication device that can operate as a mobile router or a home agent and a traffic amount control method.

  In order to solve the above-described problems and achieve the object, the present invention provides a communication device that operates as a mobile router in a communication system that realizes network mobility using mobile IP, and includes a current position of the own device, Statistics information management means that collects movement speed, communication media type in use, radio wave intensity, communication speed, and network delay between the opposite device and holds as statistical information, and is held by the statistical information management means Based on the statistical information, the fluctuation prediction means for predicting the fluctuation of the communication band that occurs with the movement of the own device, and the fluctuation prediction result in the fluctuation prediction means, transmitted from the accommodated IP terminal And a traffic volume control means for controlling the user traffic volume.

  According to the present invention, a change in the communication band is predicted based on statistical information collected and held in the past, and the amount of user traffic transmitted by the MNN connected to itself is controlled based on the prediction result. Therefore, there is an effect that it is possible to prevent the MNN from determining that the network is congested when the communication band is changed by adjusting the traffic amount before the communication band rapidly changes.

FIG. 1 is a diagram illustrating a configuration example of a first embodiment of a communication system including a communication device according to the present invention. FIG. 2 is a diagram illustrating a configuration example of the mobile router according to the first embodiment. FIG. 3 is a diagram showing an example of management information. FIG. 4 is a diagram illustrating an example of a communication band change prediction result. FIG. 5 is a diagram illustrating an example of a communication band change prediction result.

  Embodiments of a communication apparatus and a traffic amount control method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of a first embodiment of a communication system including a communication device according to the present invention. The communication system shown in FIG. 1 includes a mobile router (MR) 1 that is a communication apparatus according to the present invention, an IP terminal (MNN) 2 that is connected to a mobile network under the control of MR1 and moves together with MR1, A plurality of access routers (AR) 3 ₁ , 3 ₂ , 3 ₃ ,..., 3 _n that are connection destinations, a home agent (HA) 4 that is arranged in a fixed network such as the Internet and manages the movement of MR1, and MNN2 And an IP terminal (CN) 5 arranged in a fixed network, for example. Note that user traffic between the MNN 2 and the CN 5 is IP-in-IP encapsulated and transferred by the MIP tunnel between the MR 1 and the HA 4.

Further, MR1 as an initial state, complete the location registration under the control AR3 _1, assumed to be in a state connected to the AR3 _1. In this state, when the mobile body including an MR1 and MNN2 has moved to AR3 ₂ under (communication area), MR1 will receive a router advertisement from the AR3 _2. Then, by receiving the router advertisement, a care-of address (CoA # 2) that can be used under AR3 ₂ is acquired, and by registering the location of CoA # 2 with HA4, communication between MNN2 and CN5 is continued. It is possible.

  FIG. 2 is a diagram illustrating a configuration example of the mobile router (MR) according to the first embodiment. MR1 of the present embodiment includes a routing processing unit 10, a radio communication unit 20, a geographic information measurement unit 30, and a movement plan setting unit 40.

  The routing processing unit 10 includes a TCP proxy function unit 11, a network mobility control unit 12, a statistical information management unit 13, and a movement plan management unit 14. The characteristic processing (details will be described later) of the mobile router according to the present embodiment. ).

  The wireless communication unit 20 has a plurality of communication media (not shown) corresponding to different wireless communication methods, and performs wireless connection with an access router (AR) using an arbitrary communication medium. 2 shows the mobile router 1 having a single wireless communication unit 20, the mobile router 1 may include a plurality of wireless communication units 20.

  The geographic information measuring unit 30 uses a positioning system such as GPS (Global Positioning System) to acquire position information of the own device (MR1). The movement plan setting unit 40 provides a user with a function for setting a destination (destination) of a moving body including MR1 and MNN2.

  The TCP proxy function unit 11 (corresponding to traffic volume control means) has a function of controlling communication with the MNN2, and transfers user data transmitted and received by the MNN2 using the MIP tunnel with the HA4. At the same time, it controls user traffic from MNN2 to CN5. When the CN 5 side has a component that realizes a function similar to that of the TCP proxy function unit 11 (hereinafter referred to as “opposite TCP proxy function unit” for convenience of explanation), the user traffic control is a pseudo confirmation response to the MNN 2. This is done by replying and adjusting the window size. The pseudo-reply response operation (pseudo-acknowledge operation) is not particularly defined, but when the TCP proxy function unit 11 receives a packet transmitted from MNN2 to CN5, it immediately returns the confirmation response to MNN2. To do. Such a control procedure is described, for example, in Patent Document 1 and Japanese Patent Application Laid-Open No. 2008-172521.

  In addition, when the CN 5 side has a counter TCP proxy function unit, the TCP proxy function unit 11 transmits data between the counter TCP proxy function unit at a higher speed than when using TCP, for example, using UDP (User Datagram Protocol). In addition, the original retransmission control is performed to transmit and receive data reliably at high speed.

  The network mobility control unit 12 performs NEMO location registration to the HA 4 via the communicable AR, and forms a MIP tunnel between the HA 4 and the MR 1 to continue communication between the CN 5 and the MNN 2. Also, the TCP proxy function unit 11 is notified of available MIP tunnels.

  The statistical information management unit 13 includes an average moving speed of the mobile body (that is, an average moving speed of the own device, hereinafter simply referred to as “moving speed”), a communication media type and radio wave intensity that the wireless communication unit 20 is currently using, The current communication speed, the network delay with the opposing TCP proxy function unit, and the current position are collected at a predetermined timing, and the collected information is held as statistical information. Among the above pieces of information, the moving speed and the current position are acquired from the geographic information measuring unit 30. Further, the currently used communication media type and radio wave intensity are acquired from the wireless communication unit 20, and the current communication speed and network delay are acquired from the TCP proxy function unit 11. The moving speed may be calculated based on position information (current position and position information acquired in the past). Further, the statistical information management unit 13 may also acquire a network prefix that is a position on the IP network topology from the network mobility control unit 12 and store it together with the above information. The operation using this network prefix will be described in the second embodiment.

  The movement plan management unit 14 (corresponding to the fluctuation prediction means) acquires information on the movement direction specified from the destination (destination) set by the user from the movement plan setting unit 40, and the acquired movement direction information, Based on the statistical information managed by the statistical information management unit 13, the fluctuation of the communication band due to movement is predicted.

  FIG. 3 is a diagram illustrating an example of management information collected and managed by the statistical information management unit 13. As illustrated, the management information includes information such as a point (position), communication media, average moving speed, communication speed and delay (network delay), and radio wave intensity. The movement plan management unit 14 uses this statistical information, and based on the current MR1 position (point) and movement speed, the currently usable communication media, the communication quality (average communication speed, (Average network delay and average field strength) can be determined (estimated). Further, in the travel plan setting unit 40, when the destination is set, the average communication speed, the average network delay and the average radio wave intensity at a predetermined point on the travel plan route to the set destination can be obtained. Is possible.

Next, the detailed operation of MR1 of the present embodiment will be described. Here, for simplification, MR1 that can use a single communication medium will be described. Further, MR1 is set destination and the moving path of the moving body by the moving plan setting unit 40, in accordance with the settings, it starts moving from the initial state (AR3 while connected to ₁₎ shown in FIG. 1, a description will be given of the operation when moving to the AR3 ₃ subordinate via the AR3 ₂ under. Further, it is assumed that user traffic is generated from MNN2 toward CN5 during this movement.

MR1 is, with the movement, executes the handover when performing switching of the connection point of the case, and AR3 ₂ to AR3 ₃ to switch the connection points from the AR3 ₁ to AR3 _2, the location registration to HA4 Do.

  At this time, the movement plan management unit 14 moves to the destination set by the statistical information (see FIG. 3) and the movement plan setting unit 40 that have been collected and managed by the statistical information management unit 13 so far. Based on the above, a change in the communication band on the moving route to the destination is predicted.

  FIG. 4 is a diagram illustrating an example of a change prediction result of the communication band by the movement plan management unit 14, and shows a change prediction result of the communication band from the start of movement to the destination. That is, as the mobile object including MR1 moves, the communication band greatly increases when the point a is reached, and then the communication band is not so large for a while after reaching the point b. The example shows a case where it is predicted that the communication band will be reduced by half (significantly reduced) when it fluctuates and further reaches point c.

  In addition, the movement plan management unit 14 notifies the TCP proxy function unit 11 of the timing and amount of fluctuation of the communication band in accordance with the predicted change of the communication band. That is, the movement plan management unit 14 acquires the current position from the geographic information measurement unit 30 at a predetermined timing, determines whether or not the communication band varies from the comparison result with the prediction result, Notify that. The movement plan management unit 14 does not acquire the current position from the geographic information measurement unit 30 at a predetermined timing, but collects various information (various information included in the statistical information) by the statistical information management unit 13. The current position output from the geographic information measuring unit 30 may be received to determine whether or not the communication band varies. That is, the movement plan management unit 14 may determine whether or not the communication band fluctuates following (or simultaneously with) the collection operation of various information by the statistical information management unit 13.

  A specific example of the operation of the movement plan management unit 14 will be described. For example, when the prediction result is as shown in FIG. 4, the movement plan management unit 14 compares the current position with the prediction result, and detects that its own device (MR1) approaches the point a in FIG. The TCP proxy function unit 11 is instructed to increase the communication band. In the instruction, the communication band after the change or the change amount of the communication band is notified.

  The TCP proxy function unit 11 that has received the increase notification of the communication band from the movement plan management unit 14 determines the amount of user data transmitted from the MNN 2 based on the own buffer size and the predicted communication band after the change (from the point a) (user Traffic volume). Specifically, the amount of user traffic is increased to an amount that can be transmitted after passing through point a. That is, the MNN 2 is notified to increase the window size, and an acknowledgment for the data transmitted by the MNN 2 is transmitted without delay. Thereby, the MNN 2 recognizes that the communication band has increased, and increases the amount of user traffic to be transmitted. Of the user traffic received between the point where the instruction to increase the communication band is received and the point a, the increased amount of user traffic is buffered in the buffer of the TCP proxy function unit 11 of the MR1 and reaches the point a. Then, it is transmitted to CN5 via the MIP tunnel.

  Furthermore, when the movement plan management unit 14 detects that MR1 has approached the point b, the movement plan management unit 14 notifies the TCP proxy function unit 11 that the communication band is reduced. When the TCP proxy function unit 11 is notified that the communication band fluctuates, the user is based on the own communication buffer size and the predicted communication band after the change (after the point b) as in the case where the point a approaches the point a. Control traffic volume. However, if it is determined that the fluctuation amount of the communication band can be absorbed by the own buffer size, that is, even if the MNN2 continues to transmit with the user traffic volume so far, it can be buffered by its own buffer, and the point b When it can be determined that the transmission can be sufficiently performed in the predicted communication band after the passage, the MNN 2 is not instructed to change the user traffic amount. As a result, the MNN 2 can continue communication without detecting a change in the communication band.

  Thereafter, whenever the movement plan management unit 14 detects that the communication band change is predicted to approach a point where the change is predicted, the movement plan management unit 14 notifies the TCP proxy function unit 11 of the change contents of the communication band. Based on the notification content, an instruction to change the amount of user traffic is issued to MNN2 as necessary. For example, when detecting that MR1 has approached the point c, the movement plan management unit 14 notifies the TCP proxy function unit 11 that the communication band is reduced, and the TCP proxy function unit 11 Based on the predicted communication band after passing through point c, it is determined that the amount of user traffic needs to be reduced, and the amount of user traffic is reduced to an amount that can be transmitted after passing through point c. That is, the MNN 2 is notified to reduce the window size, and the acknowledgment response to the data transmitted by the MNN 2 is delayed and transmitted. As a result, the MNN 2 recognizes that the communication band has decreased, and reduces the amount of user traffic to be transmitted.

  With the above control, for example, control is performed such that the user traffic volume is increased after the communication band is measured after reaching point a in FIG. 4, or the user traffic volume is decreased after the communication band is measured after reaching point c. Compared with the case where it carries out, the improvement of communication efficiency can be expected. Further, when the amount of user traffic is reduced after the communication band is measured after reaching the point c, when the data transmitted from the MNN2 exceeds the buffer amount of the TCP proxy function unit 11, the MNN2 is network congestion. Therefore, it is possible to prevent the MNN2 from autonomously limiting the amount of user traffic.

  As described above, the communication device (mobile router) according to the present embodiment collects and holds statistical information (moving speed, communication media type and radio wave intensity, communication speed, Predict the change in the communication bandwidth on the travel route to the destination based on the information including the network delay between the opposing TCP proxy function part and the travel route to the destination, and the prediction result and current position The amount of user traffic (amount of user data) transmitted by the MNN connected to itself is determined (controlled) according to the comparison result. As a result, it is possible to prevent the MNN from determining that the network is congested when the communication bandwidth actually fluctuates by adjusting the traffic volume before the communication bandwidth rapidly changes. That is, communication efficiency can be improved.

  In the above description, the movement plan management unit 14 performs the fluctuation prediction of the communication band over all the movement routes to the destination in advance, and the description is made as if the fluctuation prediction result as shown in FIG. 4 is obtained. However, the prediction may be divided into a plurality of times at a constant time interval, or the prediction may be divided into a plurality of times for every predetermined distance (each time the fixed distance is moved).

  Moreover, although the case where CN5 side has a counter TCP proxy function part was demonstrated, even if it is a case where CN5 side does not have this function, the same user traffic amount control is possible. That is, when the CN 5 side does not have the counter TCP proxy function unit, the TCP proxy function unit 11 can realize user traffic control by performing TCP communication with the CN 5. In this case, both TCP from MNN2 and TCP from CN5 are once terminated at MR1 (TCP proxy function unit 11). In this case, the TCP proxy function unit 11 may also perform control (window control) of the user traffic amount transmitted from the CN 5.

  Further, in the present embodiment, for the sake of simplification, description has been made assuming MR1 having a single communication medium, but a configuration having a plurality of communication media may also be used. In this case, the network mobility control unit 12 notifies the TCP proxy function unit 11 that a plurality of MIP tunnels can be used. In addition, the movement plan management unit 14 notifies the TCP proxy function unit 11 of a change in the communication band for each communication medium.

  Moreover, although the description has been made assuming that the destination and the travel route are set, these pieces of information may not be set. However, it is assumed that the statistical information includes a time stamp (information on the date and time when information is collected) or information corresponding thereto. In this case, the movement plan management unit identifies the movement direction from the statistical information and the current position, and predicts fluctuations in the communication band based on the movement direction, the current position, and the statistical information. That is, if the moving direction is known, a future moving route can be predicted from the current position and moving speed. Therefore, for example, the predicted arrival position is predicted from the position predicted to arrive after N seconds (expected arrival position) and statistical information. It is possible to predict the communication band at

  Further, the description has been made assuming the user traffic transmitted from MNN2 to CN5, but the same control is possible for the user traffic transmitted from CN5 to MNN2. In this case, the predicted communication band accompanying the movement of MR1 is notified to HA4, and HA4 is configured to execute the same control as the control in TCP proxy function unit 11 of MR1. The notification of the predicted bandwidth to the HA 4 can be easily notified by expanding the location registration BU message, expanding the header portion when the user traffic is IP-in-IP encapsulated by the MIP tunnel, or the like.

  In the above description, the timing at which the movement plan management unit 14 acquires the current position from the geographic information measurement unit 30 is not particularly defined, but this timing may be variable based on the moving speed. That is, when the geographic information measuring unit 30 acquires the current position information, the moving speed information is also acquired, or the previously acquired position information and the current position information and the elapsed time from the previous acquisition to the current acquisition Based on the movement speed, the position information (current position) is acquired with a shorter period as the speed increases according to the acquired or estimated movement speed information. As a result, it is possible to improve followability with respect to fluctuations in the communication band and to prevent the user traffic volume control operation from being executed in a cycle shorter than necessary. Similarly, the timing at which statistical information is collected by the statistical information management unit 13 may be changed according to the moving speed.

Embodiment 2. FIG.
Next, the mobile router according to the second embodiment will be described. The configuration of the communication system including the mobile router according to the present embodiment and the configuration of the mobile router itself are the same as those in the first embodiment (see FIGS. 1 and 2). Similarly to the first embodiment, MR1 has a destination and a moving route set by the movement plan setting unit 40, and is connected to the initial state (AR3 ₁₎ shown in FIG. The operation in the case where the movement is started from the (state) and moved to the AR3 ₃ via the AR3 ₂ will be described. It is assumed that user traffic is generated from MNN2 to CN5 while moving from the initial state to AR3 ₃ . In the following description of the operation, parts different from those of the mobile router of the first embodiment are mainly described, and parts that are not described are the same as those of the first embodiment.

  The operation of the mobile router (MR1) of the present embodiment will be described. MR1 of the present embodiment is characterized in that a network prefix indicating a position on the IP network topology is held as one piece of information included in statistical information, and handover control is performed in consideration of this network prefix. To do.

That is, the MR1 statistical information management unit 13 of the present embodiment combines the network prefix in addition to the position, moving speed, media information used, etc. (see FIG. 3) shown in the first embodiment. Collect and keep. Then, when the movement plan management unit 14 predicts a change in the communication band based on the statistical information held in the statistical information management unit 13, a change in the network prefix (a change in connectable AR) is also included. Predict. FIG. 5 is a diagram illustrating an example of a predicted change in the communication band by the movement plan management unit 14 according to the present embodiment. In addition to the predicted change in the communication band for each section on the movement route, the connection is made in each section. The possible AR change prediction results are also shown. Specifically, it can communicate with AR3 _{1 in} the section from the start of movement to point b, can communicate with AR3 _{2 in} the section from point b to point c, and communicates with AR3 ₃ after passing point c. This is shown together with the prediction result of the communication band.

In addition, the TCP proxy function unit 11 of MR1 of the present embodiment performs the same operation as that described in the first embodiment. The network mobility control unit 12 performs connection destination switching (handover) based on the prediction result (change prediction result of connectable AR) in the movement plan management unit 14. That is, upon detecting that close to the point b on the basis of the acquired position information in a geographic information measurement unit 30, in preparation for the occurrence of the location registration with the destination switch to AR3 ₂ after point b pass, AR3 ₂ CoA used for location registration when switching to is acquired. Then, as soon as it reaches the point b, it performs position registration for switching the connection destination to the AR3 ₂ relative HA4. By the control operation of the network mobility control unit 12, the MR1 of the present embodiment can start location registration before receiving the router advertisement from the AR3 ₂ . As a result, stable handover can be realized, and the frequency with which communication is interrupted due to failure of handover can be reduced and the time during which communication is interrupted can be shortened.

  As described above, the mobile router of the present embodiment collects and holds the network prefix information in addition to the statistical information collected and held by the mobile router of the first embodiment. Along with the communication bandwidth control (window control) described above, the necessity of handover is determined, and if it is detected that the handover execution position (switching point of the access router that is the connection destination) is approaching, the handover operation (position The CoA used in the registration process is acquired. Thereby, after reaching the handover execution position, the position registration can be performed immediately without receiving the router advertisement and acquiring the CoA, and as a result, it is possible to avoid communication disconnection. The location registration using the acquired CoA is executed. Thereby, the time (communication interruption time) when communication is interrupted can be shortened.

  In this embodiment, an example of handling user data transmitted from MNN2 to CN5 has been described. However, similar control is possible when handling user data transmitted from CN5 to MNN2. is there.

  When realizing control for user data transmitted from CN5 to MNN2, for example, MR1 notifies HA4 in advance of the travel route to the set destination, and also provides statistical information. Statistical information is notified to the HA 4 every time it is collected. As described in the first embodiment, the notification to the HA 4 is performed using an extended BU message. The HA 4 has the same function as the statistical information management unit 13 of the MR 1, and when statistical information is notified from each MR managed by the HA 4, creates more accurate statistical information based on the statistical information. . Based on the statistical information and the travel route to the destination of each MR, a change in the communication band is predicted for each MR. Further, based on the predicted change in the communication band and the current position of each MR, CN5 to MNN2 (The window size is determined and the determination result is notified to the CN 5). More simply, each MR notifies the HA 4 of the prediction result of the fluctuation of the communication band, and the HA 4 controls the user traffic from the CN 5 to the MNN 2 using the prediction result notified from each MR. Also good. In addition, the HA 4 may have a function of notifying the MR of the statistical information held in response to a request from each MR. Thus, for example, when a wireless communication unit corresponding to a new communication medium is added to the MR, even when the MR does not have statistical information for the added communication medium, the statistical information notified from the HA 4 is used. Thus, communication band control and handover control can be performed.

  MR1 can also perform the following operations using the statistical information held in the statistical information management unit 13. That is, in MR1, if it is determined that there is no communicable area of the communication media possessed by the wireless communication unit 20 based on the statistical information, the wireless communication unit 20 searches by reducing the connection point search frequency. I do. Thereby, it is possible to suppress energy consumed for searching for connection points, and energy saving can be realized.

  As described above, the communication device according to the present invention is useful for a communication device that performs wireless IP communication. In particular, even if the mobile device moves while performing IP communication and switches the access router of the wireless access point, the communication device Suitable for mobile routers that can maintain communication.

1 Mobile router (MR)
2 IP terminal (MNN)
3 ₁ , 3 ₂ , 3 ₃ , 3 _n Access router (AR)
4 Home Agent (HA)
5 IP terminal (CN)
DESCRIPTION OF SYMBOLS 10 Routing processing part 11 TCP proxy function part 12 Network mobility control part 13 Statistical information management part 14 Movement plan management part 20 Wireless communication part 30 Geographic information measurement part 40 Movement plan setting part

Claims (10)

In a communication system that implements network mobility using mobile IP, a communication device that operates as a mobile router,
Statistical information management means for collecting the current position of the own device, the moving speed, the type of communication media being used, the radio wave intensity, the communication speed, and the network delay between the opposite device, and holding as statistical information;
Based on the statistical information held by the statistical information management means, a fluctuation prediction means for predicting fluctuations in the communication band that occur with the movement of the device itself;
Traffic volume control means for controlling the amount of user traffic transmitted from the accommodated IP terminal based on the fluctuation prediction result in the fluctuation prediction means;
A communication apparatus comprising:   The communication apparatus according to claim 1, wherein the traffic volume control unit controls the user traffic volume by TCP window control. When collecting the statistical information, the statistical information management means further collects and holds network prefix information together,
The fluctuation prediction means further predicts the occurrence timing of handover based on the statistical information and network prefix information held by the statistical information management means,
3. The communication according to claim 1, wherein a CoA used in a handover process is acquired in advance from an access router serving as a handover destination access point based on a handover generation timing prediction result by the fluctuation prediction unit. apparatus.   6. The method according to claim 1, wherein it is checked whether or not a communicable area is in the vicinity based on the statistical information, and if there is no communicable area in the vicinity, the connection frequency is searched by reducing the search frequency. Item 4. The communication device according to Item 1, 2, or 3. A communication device having a function as a home agent for performing mobility management of the communication device according to any one of claims 1 to 4,
A communication band variation prediction result predicted by a mobility management target communication device is acquired, and a user traffic amount transmitted to the communication device is controlled based on the acquired variation prediction result. Communication device. A communication device having a function as a home agent for performing mobility management of the communication device according to any one of claims 1 to 4,
The statistical information collected by the communication device subject to movement management and the destination information of the communication device are acquired, and based on the acquired statistical information, the fluctuation of the communication band that occurs due to the movement of the communication device is predicted. Further, the communication device controls the amount of user traffic transmitted from the communication partner of the communication device to the communication device based on the prediction result.   If there are a plurality of communication devices subject to mobility management, based on the statistical information acquired from each of the communication devices, new statistical information with higher accuracy is newly generated, and the newly generated statistical information is used for communication bandwidth. The communication apparatus according to claim 6, wherein a fluctuation in the number is predicted.   8. The communication apparatus according to claim 7, wherein the newly generated statistical information is notified to a requesting communication apparatus in response to a request from a movement management target communication apparatus. A traffic amount control method executed by a mobile router in a communication system that realizes network mobility using mobile IP,
An information collecting step for collecting the current position of the own device, the moving speed, the type of communication media in use, the radio wave intensity, the communication speed, and the network delay between the opposite device;
Based on each information collected in the information collecting step, a fluctuation prediction step for predicting fluctuations in the communication band that occur with the movement of the own device;
A traffic volume control step for controlling the user traffic volume transmitted from the accommodated IP terminal based on the fluctuation prediction result in the fluctuation prediction step;
A traffic volume control method comprising: In a communication system that implements network mobility using mobile IP, a traffic amount control method executed by a home agent that performs mobility management of a mobile router,
An information acquisition step for acquiring the network delay between the mobile router to be managed, the position of the mobile router, the moving speed, the communication media type in use, the radio wave intensity, the communication speed, and the opposite device
Based on each piece of information acquired in the information acquisition step, user traffic transmitted to the mobile router is predicted based on the prediction result, by predicting fluctuations in the communication bandwidth that occur with the movement of the managed mobile router. A user traffic volume control step for controlling the volume;
A traffic volume control method comprising:

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