JP2008227927A - Mobile communication system and mobile communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a communication band from being used only by a control message received and transmitted between a terminal and a management device. <P>SOLUTION: The mobile communication system comprises a management device (100) and a relay device (300) which are connected to a network (400) and a plurality of terminals (10, 20, and 30) which transmit the control message to be notified to the management device to the relay device. The relay device includes a message control portion (303) summarizes the control messages received from the individual terminals to form a first summary message and sends it to the management device. The management device includes a protocol processing portion (102) for generating response messages to the terminals receiving control information to the management device, and a message control portion (103) which transmits a second aggregated message formed by summarizing the response messages for the individual terminals corresponding to the individual control messages contained in the received first summary message to the relay device. The message control portion of the relay device transmits the response messages contained in the second aggregated message received from the management device to the individual terminals. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a system for using a terminal that can move between a plurality of networks, such as a portable information terminal.

  2. Description of the Related Art Conventionally, there has been known an IP mobility technique that enables a terminal connected to a certain network to continuously perform IP communication in a destination network even when connected to a different network due to movement. As a protocol that supports this IP mobility technology, there is a so-called mobile IP based on IPv6 (Internet Protocol version 6) defined in RFC2462.

  In communication using mobile IP, all terminals need to register their location information with the home agent at the time of movement between networks and every predetermined period after movement. Therefore, when the number of terminals is large, there is a possibility that the network band is excessively occupied by the control message for location registration.

As a technique in view of a problem caused by transmitting a control message from a terminal like the above problem, for example, there is a technique described in Patent Document 1 described later. Patent Document 1 discloses a technique for monitoring whether or not data transfer has occurred within a predetermined period after location registration once, and limiting re-registration message transmission according to the occurrence status. .
JP-T-2005-514824

  Although the technique of the above-mentioned patent document 1 is intended to reduce the number of control messages based on the presence / absence of data transfer after location registration, there are various usage forms of terminals, and communication is not always performed after registration. Therefore, after the registration, if the predetermined period has passed without the terminal performing communication, it is necessary to newly register the location. This technology limits the number of re-registrations and does not limit the number of new registrations. Therefore, it is difficult to alleviate the network congestion caused by the transmission of the control message by the technique disclosed in Patent Document 1.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for preventing occupation of a communication band by a control message exchanged between a terminal and a management apparatus.

  A mobile communication system according to the present invention includes a management apparatus and a relay apparatus connected to a network, and a plurality of terminals that transmit a control message including control information to be notified to the management apparatus to the relay apparatus, and the relay An apparatus includes a message control unit that aggregates control messages received from the plurality of terminals to form a first aggregate message and transmits the first aggregate message to the management apparatus. A protocol processing unit that generates a response message for the terminal that has notified the control information to the device, and a control message included in the first aggregate message received from the relay device and generated for each terminal corresponding to the control message The received response messages are aggregated to form a second aggregated message, and the second aggregated message is transmitted to the relay device And a message control unit, a message control unit of the relay apparatus recognizes the reply message included in the second aggregate messages received from the management apparatus transmits the response message to the terminal.

  According to the present invention, when a control message exchanged between a plurality of terminals and a management device is sent to the network, the control message is aggregated and sent out, so that the communication band of the network is occupied by the control message. This can be prevented. Thereby, the network can be used effectively and communication congestion can be avoided.

  FIG. 1 shows a system configuration of an embodiment of the present invention. The system 1000 includes a movable terminal 10, a terminal 20, and a terminal 30 such as a portable information terminal, and a management device 100, a relay device 200, and a relay device 300 connected to a computer network 400 such as the Internet.

  The management device 100 is a device that collectively manages control information of each terminal (10, 20, 30), and is, for example, a server device that is operated by an operator that provides services to these terminals. The relay device 200 and the relay device 300 are devices such as routers that relay communication between each terminal (10, 20, 30) and the management device 100.

  The link 1 is a physical link such as Ethernet (registered trademark) or a wireless LAN to which the relay device 200 is connected. The link 2 is a physical link such as Ethernet (registered trademark) or a wireless LAN to which the relay device 300 is connected. FIG. 1 shows a situation where the terminal 10 and the terminal 20 connected to the link 1 have moved to the link 2 to which the terminal 30 is connected.

  Each terminal (10, 20, 30) has a function of transmitting a control message including control information to be notified to the management apparatus 100 to the relay apparatus (200 or 300) of the currently connected link (1 or 2). Have. As a control message in the system 1000, for example, a location registration message used in the IP mobility technology, that is, a message in which information for notifying a current terminal connection state is described can be applied. The management apparatus 100 that has received the control message from the terminal transmits a response message to the terminal.

  FIG. 2 shows functional configurations of the management apparatus 100 and the relay apparatus 300. The relay device 200 has the same configuration as the relay device 300, but the illustration of the relay device 200 is omitted for simplification of the drawing.

  As shown in FIG. 2, the relay device 300 includes a router unit 301 that is a router function related to the IP layer, a protocol analysis unit 302 that is a server function related to the IP layer, and security-related data such as key information for encryption. Security information management unit 304 that holds the control information, a control information management unit 305 that records the control information included in the control message, and a message control unit 303.

  The message control unit 303 of the relay apparatus 300 aggregates control messages received from the terminals (10, 20, 30) to form a first aggregate message, and transmits it to the management apparatus 100. In addition, the message control unit 303 reconstructs a response message for each terminal from a later-described second aggregate message received from the management apparatus 100, and transmits them to the terminal.

  The management device 100 is related to security such as a router unit 101 that is a router function in the IP layer, a protocol processing unit 102 that generates a response message for a terminal that has notified control information to the own device, and key information at the time of encryption. A security information management unit 104 that holds data to be stored, a control information management unit 105 that records control information included in the control message, and a message control unit 103.

  The message control unit 103 of the management apparatus 100 recognizes the control message of each terminal from the first aggregate message received from the relay apparatus 300, and reads and registers the control information included in these control messages. Further, the message control unit 103 aggregates the response messages generated for the terminals corresponding to the registered control information to form a second aggregated message, and transmits it to the relay device 300.

  The operation of the system 1000 will be described with reference to the sequence shown in FIG. Here, it is assumed that the terminal 10 and the terminal 20 are currently connected to the link 2 as shown in FIG.

  When the terminal 10 sends a control message describing control information for the management device 100 to the link 2 (step S1), the relay device 300 receives it and temporarily stores it (steps S2 and S3). Further, when receiving the control message from the terminal 20, the relay device 300 also temporarily stores it (steps S4, S5, S6).

  The relay device 300 selects control messages having the same destination from the stored control messages, here, control messages addressed to the management device 100, and aggregates them to form one message (step S7). When the messages are aggregated, the aggregated data volume is aggregated so as to be smaller than the total data volume of the original control message. For example, a method of compressing a control message or extracting only necessary parts such as control information and source information included in each control message can be used. As a result, a first aggregate message is formed. Then, the formed first aggregation message is transmitted to the management apparatus 100 via the network 400 (step S8).

  When the management apparatus 100 receives the first aggregate message from the relay apparatus 300 (step S9), the management apparatus 100 recognizes the control messages of the terminals 10 and 20 aggregated in the received message (step S10). Then, the control information included in each recognized control message is registered for each terminal by the control information management unit 105 (FIG. 2) (step S11).

  Subsequently, the management device 100 creates a response message for the terminal 10 and the terminal 20 in which the control information is registered (step S12), and the security information management unit 104 (FIG. 2) regarding the response message and the terminal 10 and the terminal 20 Are aggregated with the security information held by the message to form one message (step S13). As a result, a second aggregate message is formed. Then, the formed second aggregated message is transmitted to relay apparatus 300 via network 400 (step S14).

  When receiving the second aggregate message from the management apparatus 100 (step S15), the relay apparatus 300 recognizes the response message and security information addressed to each terminal (10, 20) aggregated in the received message (step S16). ). Then, the recognized response message is transmitted to each terminal (10, 20) (step S17).

  Also, the relay device 300 registers the security information recognized from the second aggregation message and the control information notified by each terminal to the management device 100 by the security information management unit 304 and the control information management unit 305 (FIG. 2). (Step S18).

  According to the system 1000 of this embodiment, when control messages exchanged between a plurality of terminals and a management device are sent to the network 400, the control messages are aggregated by the relay device 300 and the management device 100. Since it is transmitted, it is possible to prevent the communication band of the network from being occupied by the control message. Thereby, the network can be used effectively and communication congestion can be avoided.

  A more specific example is given regarding the embodiment of the present invention. FIG. 4 shows a system configuration of the first embodiment. The system 1000A according to the present embodiment is a system to which the IP mobility technology is applied. The control message transmitted from each terminal (10, 20, 30) is a position registration message in which position information indicating which link (1, 2) the terminal is connected to is described. The response message for the location registration message is a location response message including registered location information and security information used for communication in the connection environment.

  As shown in FIG. 4, the system 1000A includes a home agent 100A as a management device, and a router 200A and a router 300A as relay devices. The home agent 100A and each router (200A, 300A) are connected to the network 400. Router 200A is connected to link 1, and router 300A is connected to link 2.

  FIG. 5 shows functional configurations of the home agent 100A and the router 300A. The illustrated components correspond to those of the management device 100 and the relay device 300 shown in FIG. That is, the constituent elements shown in FIG. 5 correspond to those obtained by adding “A” to the reference numerals of the corresponding constituent elements in FIG.

  As shown in FIG. 5, the home agent 100A includes a router unit 101A, a MIP (Mobile IP) processing unit 102A as a protocol processing unit, a message aggregation / reconstruction unit 103A as a message control unit, and a security information management unit. 104A and a control information management unit 105A.

  The router 300A includes a router unit 301A, a MIP analysis unit 302A as a protocol analysis unit, a message aggregation / reconstruction unit 303A as a message control unit, a security information management unit 304A, and a control information management unit 305A.

  The operation of the system 1000A conforms to that described with reference to FIG. Hereinafter, the operation will be described. Here, it is assumed that the terminal 10 and the terminal 20 have just moved from link 1 to link 2 as shown in FIG.

  When the terminal 10 and the terminal 20 move to the link 2, the router 10A receives the router advertisement message transmitted by the router 300A according to the mobile IP procedure, or moves from the link 1 to the link 2 by the notification information detected in the MAC layer. Detect that. The terminal 10 and the terminal 20 that have detected the movement each transmit a location registration message to the home agent 100A in order to notify the movement. Here, it is assumed that the terminal 10 has transmitted a location registration message first (FIG. 3: S1).

  The location registration message transmitted from the terminal 10 reaches the router unit 301A of the router 300A via the link 2, and is then passed to the message aggregation / reconstruction unit 303A. The message aggregation / reconstruction unit 303A temporarily stores this message (S2, S3). Thereafter, when the location registration message transmitted by the terminal 20 reaches the router 300A, the message is stored in the message aggregation / reconstruction unit 303A by the same processing as described above (S4, S5, S6).

  The message aggregation / reconstruction unit 303A extracts a message with the same destination from the temporarily stored message to create one message, that is, forms a first aggregated message, and transmits it to the home agent 100A. (S7, S8).

  When the first aggregation message transmitted from the router 300A reaches the router unit 101A of the home agent 100A via the network 400, it is supplied to the message aggregation / reconstruction unit 103A (S9). The message aggregation / reconstruction unit 103A reconstructs the location registration messages of the terminal 10 and the terminal 20 from the supplied first aggregation message and passes them to the MIP processing unit 102A (S10).

  The MIP processing unit 102A processes the location registration message of each terminal (10, 20), registers the location information contained therein in the control information management unit 105A, and creates a location response message to aggregate and reconstruct the message Passed to the part 103A (S11, S12). The message aggregation / reconstruction unit 103A selects a position response message addressed to the same router, here, addressed to the router 300A from the generated position response message. Then, the selected location response message and the security information held by the security information management unit 104A regarding the terminal 10 and the terminal 20 are aggregated to form a second aggregated message, which is transmitted to the router 300A (S13). , S14).

  When the second aggregation message transmitted from the home agent 100A reaches the router unit 301A of the router 300A via the network 400, it is passed to the message aggregation / reconstruction unit 303A (S15). The message aggregation / reconstruction unit 303A reconstructs a position response message addressed to the terminal 10 and the terminal 20 from the passed second aggregated message, and transmits them to the terminal 10 and the terminal 20 (S16, S17). Further, the MIP analysis unit 302A extracts the position information and the security information from the position response messages to the terminal 10 and the terminal 20, respectively, and registers them in the security information management unit 304A and the control information management unit 305A (S18).

  As described above, according to the system 1000A of the present embodiment, the location registration message and the location response message flowing through the network 400 are reduced, so that the communication band of the network 400 can be effectively used.

  Example 2 relating to the embodiment of the present invention will be described with reference to the flowcharts of FIGS. In the present embodiment, in the system 1000A (FIG. 4) to which the IP mobility technique is applied as in the first embodiment, the timing at which the router 300A forms the first aggregation message is defined.

  Assuming a situation immediately after the terminal 10 and the terminal 20 have moved to the link 2 of the router 300A, the procedure according to FIG. 6 will be described. When the router 300A receives a message (RS: Router Solicitation) requesting a router advertisement (RA: Router Advertisement) according to the mobile IP from the terminal 10 and the terminal 20 moved to the link 2 (FIG. 6: Step S21), Router advertisement is performed according to the request (step S22). Further, the router 300A sets the timer A when the advertisement message is transmitted (step S23).

  While the timer A is operating, the router 300A waits for a duplicate address detection (DAD: Duplicate Address Detection) message conforming to the mobile IP to arrive from each terminal (step S24). When the timer A expires (step S25: Yes), the source address of the duplicate address detection message received during the timer operation is recorded (step S26).

  Subsequently, the router 300A waits for arrival of the above-described location registration message from all terminals corresponding to the recorded transmission source address (step S27). Here, it is assumed that the addresses of the terminals 10 and 20 are recorded as the source addresses. When the router 300A detects that the location registration message has been received from these terminals 10 and 20 (step S28: Yes), the router 300A aggregates the received messages to form a first aggregate message (step S29). The subsequent processing is the same as the processing after step S8 in FIG.

  Moreover, it may replace with the said procedure and may be shown in FIG. In the procedure of FIG. 7, the procedure (steps S31 to S36) from when the router 300A receives the router advertisement request from the terminal to when the sender of the duplicate address detection message received during the timer A is recorded is shown in FIG. This is the same as the procedure described above.

  After recording the transmission source, the router 300A sets a timer B (step S38) when a location registration message is received from any of the recorded sources, for example, from the terminal 10 (step S37). For this timer B, for example, a location registration message retransmission interval or an RTT (Round Trip Time) between the router 300A and the home agent 100A defined by the system can be applied.

  During the timer B, the router 300A waits for the recorded location registration message from the other transmission source (terminal 20) (step S39), and when it times out (step S40: Yes), aggregates the received location registration messages. A first aggregate message is formed (step S41).

  According to the second embodiment, since the message aggregation timing is controlled by the timer, it is possible to limit the number of messages to be aggregated at one time, thereby making the processing of the router 300A more efficient. Further, by changing the timer according to the communication status of the network 400, the terminal location registration message can be appropriately delivered to the home agent 100A.

  Example 3 relating to the embodiment of the present invention will be described. In the system 1000A (FIG. 4) to which the IP mobility technology is applied as in the first embodiment, each terminal (10, 20, 30) needs to periodically notify the home agent 100A of the location information of the terminal itself. is there. The present embodiment relates to periodic notification after the position information is notified once.

  The operation of this embodiment will be described with reference to the flowchart shown in FIG. When the router 300A transmits a position response message reconstructed from the second aggregate message to each terminal (step S51, FIG. 3: S17), the number of responses is recorded for each terminal (step S52). Then, it is determined whether or not the number of responses has reached a preset threshold value (step S53).

  As a result of the determination, if there is a terminal whose response count has reached the threshold, the terminal is considered to be highly likely to perform location registration periodically, and the terminal is recorded as a periodic notification candidate (step S54).

  FIG. 9 shows an example of a record related to periodic notification of location registration. In the illustrated list, the destination of the position response message transmitted from the terminal, the ID of the terminal, the number of times of the position response message for the terminal, and information indicating whether or not it is a regular notification candidate are recorded. Here, it is assumed that the threshold used for determining the regular notification candidate is set to “3 times”, for example. In this case, from the illustrated list, the terminal 10 and the terminal 20 whose response count is still “once” are not listed as candidates, while the terminal 30 whose response count reaches the threshold “3” is periodically notified. Candidate for

  The router 300A refers to the above record to check whether or not there is a periodic notification candidate. If there is a candidate such as the terminal 30 in FIG. 9 (step S55: Yes), the router 300A A message requesting to send a registration message is sent (step S56). The terminal that has received this request switches control to transmit a location registration message when receiving a transmission request from the router 300A, instead of voluntarily transmitting a location registration message.

  Thereafter, the router 300A receives the location registration message transmitted from the terminal in accordance with the above request or the location registration message spontaneously transmitted from the terminal (step S57), and the above-described description with reference to FIG. The processing is continued by the procedure (FIG. 3: S3, S6˜).

  According to the third embodiment, since the router 300A presents the transmission timing of the location registration message to a terminal that is predicted to perform periodic location registration, it is avoided that the periodic transmission timing varies. it can. As a result, messages can be efficiently collected by the router 300A.

  Example 4 relating to the embodiment of the present invention will be described. This embodiment relates to encryption of control messages exchanged in the system 1000 (FIG. 1).

  The operation of this embodiment will be described along the sequence shown in FIG. Each terminal (10, 20, 30) encrypts the control message and transmits it to the relay device 300 (steps S61, S62).

  When receiving the control message from each terminal (step S63), the relay device 300 returns them to plaintext data by decryption processing and aggregates them (steps S64 and S65). The relay apparatus 300 forms a first aggregate message from the aggregated data, encrypts it, and transmits it to the management apparatus 100 (steps S66 and S67).

  When receiving the first aggregate message from the relay device 300 (step S68), the management device 100 decrypts the message (step S69). The subsequent processing is the same as that described above (FIG. 3: S10-).

  According to the fourth embodiment, when the relay device 300 forms the first aggregate message to be transmitted to the management device 100, the encrypted control messages are once decrypted and aggregated. Can be reduced. The management device 100 can obtain a plaintext control message only by decrypting the first aggregate message. Therefore, the processing load on the management apparatus 100 can be reduced as compared with the case where the encrypted control messages are aggregated as they are.

It is a block diagram which shows the system configuration | structure of embodiment by this invention. It is a block diagram which shows the function structure of the management apparatus and relay apparatus of embodiment. It is a sequence diagram which shows operation | movement of embodiment. It is a block diagram which shows the system configuration | structure of Example 1 regarding embodiment. FIG. 3 is a block diagram illustrating functional configurations of a management device and a relay device according to the first embodiment. It is a flowchart which shows the procedure of Example 2 regarding embodiment. 10 is a flowchart illustrating another procedure of the second embodiment. It is a flowchart which shows the procedure of Example 3 regarding embodiment. It is explanatory drawing regarding the response recording in Example 3. FIG. It is a sequence diagram which shows operation | movement of Example 4 regarding embodiment.

Explanation of symbols

1000,1000A system
100 management unit
200,300 relay device
400 network
10,20,30 terminal
1,2 links
101, 301: Router unit, 102: Protocol processing unit, 103, 303: Message control unit, 104, 304: Security information management unit, 105, 305: Control information management unit, 302: Protocol analysis unit

Claims (12)

A management device and a relay device connected to the network, and a plurality of terminals that transmit a control message including control information to be notified to the management device to the relay device,
The relay device includes a message control unit that aggregates control messages received from the plurality of terminals to form a first aggregate message and transmits the first aggregate message to the management device;
The management device recognizes the control message included in the first aggregation message received from the relay device and a protocol processing unit that generates a response message for the terminal that has notified the control information to the own device, and corresponds to the control message A message control unit that aggregates the response messages generated for each terminal to form a second aggregate message and transmits the second aggregate message to the relay device;
The mobile communication system, wherein the message control unit of the relay device recognizes a response message included in the second aggregated message received from the management device and transmits the response message to the terminal.   The mobile communication system according to claim 1, wherein the plurality of terminals transmit a control message including position information indicating that the terminal is connected to the relay apparatus as the control information. The plurality of terminals transmit a duplication detection message for detecting duplication of addresses to the relay device before transmission of the control message including the position information,
The message control unit of the relay device records a transmission source of the duplicate detection message received in a predetermined period, and forms the first aggregated message by control messages received from all terminals corresponding to the recorded transmission source. The mobile communication system according to claim 2. The plurality of terminals transmit a duplication detection message for detecting duplication of addresses to the relay device before transmission of the control message including the position information,
The message control unit of the relay device records the transmission source of the duplicate detection message received during a predetermined period, and the control message received from any terminal corresponding to the recorded transmission source and the predetermined period after receiving the control message 3. The mobile communication system according to claim 2, wherein the first aggregate message is formed by the control message received in the first step. The message control unit of the relay device records a terminal corresponding to the second aggregated message from the management device, and sends a control message transmission request to a terminal whose number of recording exceeds a specified value.
The mobile communication system according to any one of claims 1 to 4, wherein the plurality of terminals transmit a control message to the relay device when receiving the transmission request. The plurality of terminals encrypt a control message to be transmitted to the relay device,
The message control unit of the relay device decrypts the encrypted control message and aggregates it to form the first aggregated message, and encrypts and transmits the first aggregated message. Item 6. The mobile communication system according to any one of Items 1 to 5. In a system comprising a management device and a relay device connected to a network, and a plurality of terminals that transmit a control message including control information to be notified to the management device to the relay device,
The relay device aggregates control messages received from the plurality of terminals to form a first aggregate message, and transmits the first aggregate message to the management device;
The management device recognizes the control message included in the first aggregation message received from the relay device, generates a response message for the terminal that has notified the control information to the own device, aggregates the generated response message, 2 aggregate messages and send the second aggregate message to the relay device;
The mobile communication method, wherein the relay device recognizes a response message included in a second aggregate message received from the management device and transmits the response message to the terminal.   The mobile communication method according to claim 7, wherein the plurality of terminals transmit a control message including position information indicating that the plurality of terminals are connected to the relay apparatus as the control information. The plurality of terminals transmit a duplication detection message for detecting duplication of addresses to the relay device before transmission of the control message including the position information,
The relay apparatus records a transmission source of a duplicate detection message received in a predetermined period, and forms the first aggregated message by control messages received from all terminals corresponding to the recorded transmission source. The mobile communication method according to claim 8. The plurality of terminals transmit a duplication detection message for detecting duplication of addresses to the relay device before transmission of the control message including the position information,
The relay device records the transmission source of the duplicate detection message received during a predetermined period, and receives the control message received from any terminal corresponding to the recorded transmission source and the control message received during the predetermined period after receiving the control message. 9. The mobile communication method according to claim 8, wherein the first aggregated message is formed by a message. The relay device records a terminal corresponding to the second aggregated message from the management device, and transmits a control message transmission request to a terminal whose number of recording exceeds a specified value.
The mobile communication method according to claim 7, wherein the plurality of terminals transmit a control message to the relay apparatus when receiving the transmission request. The plurality of terminals encrypt control messages to be transmitted to the relay device,
12. The relay device, after decrypting an encrypted control message, aggregates the encrypted control message to form the first aggregated message, and encrypts and transmits the first aggregated message. The mobile communication method according to any one of the above.

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