JP4768834B2 - Communication control system, connection processing node, and communication control method - Google Patents

Description

The present invention relates to a communication control system which is included in the mobile communication network establishes a connection to the mobile communication terminal and a predetermined connection destination, the connection processing node that is part in the communication control system, and a communication control method according to their .

  An IMT-2000 network, which is a mobile communication network for data communication, includes an SGSN (Serving GPRS Support Node) and a GGSN (Gateway GPRS Support Node) (see, for example, Patent Document 1). The SGSN receives a connection request signal (C-Plane signal) for requesting connection to a server in a PDN (PacketData Network) connected to the mobile communication network from a mobile communication terminal connected to the mobile communication network. To do. The SGSN transmits a connection request signal to the GGSN to perform connection processing. As a result of connection processing by GGSN or the like, when a connection is established between the mobile communication terminal and the server or the like, a user packet (U-Plane signal) is transmitted / received through the connection. That is, SGSN is a connection request receiving node that receives a connection request from a mobile communication terminal via a mobile communication network, and GGSN is a connection processing node that performs connection processing based on the connection request.

JP 2003-259422 A

  The SGSN is normally connected to a plurality of GGSNs, and selects a GGSN address for transmitting a connection request signal from a plurality of GGSN addresses, and transmits the connection request signal. The reason why a plurality of GGSNs are provided is for load distribution of signal connection processing and relay processing. The selection of the GGSN address is performed based on a predetermined selection logic from an APN (Access Point Name) indicating a connection destination included in a request transmitted from the mobile communication terminal and a selection list stored in the SGSN.

  The GGSN that has received the connection request signal confirms the number of connections currently managed by its own node, and allows the connection if it is less than the maximum number of simultaneous connections stored in advance in the GGSN. However, even if the number of connections managed in the GGSN is less than the maximum number of simultaneous connections, if the usable bandwidth of the GGSN is tight due to burst traffic, etc., the user after the connection is established Packets are not processed smoothly. For example, when the available bandwidth is tight, the user packet is transmitted from the GGSN to the router connected to the connected PDN, and the router discards the user packet (Policing) or buffering ( (Shaping) is executed. This impairs the convenience for the user and causes a problem that the retransmission packet causes an increase in system processing load.

The present invention has been made to solve the above-described problems, and prevents the available bandwidth from becoming constricted in the connection processing node in the mobile communication network, and transmits and receives data via the mobile communication network. and an object that the communication control system to allow it to be performed smoothly, providing a connection processing node and a communication control method.

  To achieve the above object, a communication control system according to the present invention is included in a mobile communication network, and includes a connection request receiving node and a plurality of connection processing nodes connected to the connection request receiving node. A connection request receiving node for receiving a connection request from a mobile communication terminal connected to a mobile communication network via a mobile communication network designating a connection destination; A connection processing node that transmits a connection request received by the connection request accepting unit is selected from a plurality of connection processing nodes, a connection request is transmitted to the selected connection processing node, and a response to the connection request is sent to the connection processing node If the connection request processing means received from the server and the response received by the connection request processing means do not perform connection processing based on the connection request, The connection request processing means is made to transmit the connection request to the subsequent processing node, and the connection processing node related to the response is sent to the destination determination means for a predetermined period based on the information included in the response. A connection processing node that receives the connection request from the connection request receiving node and a bandwidth usage measuring unit that measures the bandwidth usage in the local node by the connection established by the local node. A connection request receiving unit that performs connection processing based on the bandwidth usage measured by the bandwidth usage measuring unit, whether to perform connection processing based on the connection request received by the connection request receiving unit; Connection that performs connection processing between the mobile communication terminal and the connection destination based on the connection request when the connection processing is determined by the connection determination unit Period notification means for notifying the connection request receiving node of information for excluding the own node from the connection request transmission destination for a predetermined period, when it is determined by the connection means and the connection possibility determination means that the connection processing is not performed. And comprising.

  In the communication control system of the present invention, the connection processing node determines whether or not to perform connection processing based on the connection request based on the bandwidth usage in the own node. When it is determined that the connection processing is not performed by the above determination when the bandwidth usage is so large that there is a risk of reducing the efficiency of connection processing or data transmission / reception via the connection, a predetermined period, The connection processing node notifies the connection request receiving node that the own node is excluded from the connection request transmission destination. When the above notification is made in response to the connection request, the connection request receiving node excludes the connection processing node from the connection request transmission destination for a predetermined period.

  That is, in the communication control system of the present invention, when the bandwidth usage at the connection processing node is so large that there is a risk of reducing the efficiency of data transmission / reception via the connection processing or the connection, a predetermined period, New connection processing is not performed. Therefore, the bandwidth usage at the connection processing node decreases during that time. Therefore, according to the communication control system of the present invention, it is possible to prevent the available bandwidth from being constricted in the connection processing node in the mobile communication network, and to smoothly transmit and receive data via the mobile communication network.

  It is desirable that the period notifying unit of the connection processing node determines a predetermined period according to the band usage measured by the band usage measuring unit. According to this configuration, the period during which no new connection processing is performed in the connection processing node can be made appropriate according to the bandwidth usage. As a result, it is possible to prevent the period during which new connection processing is not performed from becoming excessively long, and to prevent the available bandwidth from becoming tight in the connection processing node appropriately.

  The connection request processing means of the connection request receiving node includes information indicating the number of connection processing nodes that can be selected as a connection request transmission destination and the number of times of transmission of the connection request in the connection request transmitted to the selected connection processing node, The connection processing node connection possibility determination means determines the number of connection processing nodes that can be selected as the connection request transmission destination indicated by the information included in the connection request received by the connection request reception means and the number of times the connection request has been transmitted. In comparison, when the number of times of transmission of the connection request is equal to or greater than the number of connection processing nodes that can be selected as the connection request transmission destination, the connection processing based on the connection request is performed regardless of the determination based on the bandwidth usage. It is desirable to judge. According to this configuration, it is possible to reliably perform connection processing at any of the connection processing nodes.

  The connection request processing means of the connection request receiving node selects a connection processing node that transmits the connection request from a plurality of connection processing nodes corresponding to the connection destination specified by the connection request, and the control means of the connection request receiving node is In accordance with the connection destination specified by the connection request, the transmission destination determination unit excludes the connection processing node related to the response from the connection request transmission destination for a predetermined period, and the bandwidth usage measurement unit of the connection processing node Measures the bandwidth usage according to the connection destination, and the connection availability determination means determines whether to perform connection processing based on the connection request received by the connection request reception means according to the connection destination. desirable. According to this configuration, it is possible to prevent the available bandwidth from being constrained in the connection processing node for each connection destination, and to enable smooth data transmission / reception via the mobile communication network.

  It is preferable that the period notification means of the connection processing node determines a predetermined period according to the connection destination. According to this configuration, the period during which no new connection processing is performed in the connection processing node for each connection destination can be made appropriate according to the bandwidth usage.

Connection processing node that is part of the communication control system of the present invention, themselves have a novel structure, each of which constitutes the present invention.

  The connection processing node according to the present invention is included in a mobile communication network, and is a connection in a communication control system including a connection request receiving node and a plurality of connection processing nodes connected to the connection request receiving node. A processing node, a bandwidth usage measuring means for measuring bandwidth usage in the own node by a connection established by the own node, a connection request receiving means for receiving a connection request from the connection request receiving node, and a connection request receiving means A connection availability determination unit that determines whether to perform connection processing based on the connection request received by the bandwidth usage measurement unit, and a connection availability determination unit that performs connection processing. If determined, connection processing means for performing connection processing between the mobile communication terminal and the connection destination based on the connection request, and connection processing means for not performing connection processing. If it is determined by the possibility determining section, characterized in that it comprises a predetermined time period, and the period notifying means for notifying the information indicating which excludes its own node from the destination of the connection request to the connection request receiving node, the.

Incidentally, the present invention can be described as an invention of a communication control system及 beauty connection processing node as described above, can also be described as an invention of a communication control method according to them as follows. This is substantially the same invention only in different categories, and has the same operations and effects.

  That is, the communication control method according to the present invention is included in a mobile communication network, and is a communication by a communication control system configured to include a connection request receiving node and a plurality of connection processing nodes connected to the connection request receiving node. A connection request receiving step in which a connection request receiving node receives a connection request via a mobile communication network designating a connection destination from a mobile communication terminal connected to the mobile communication network; The connection processing node that transmits the connection request received in the reception step is selected from a plurality of connection processing nodes, the connection request is transmitted to the selected connection processing node, and a response to the connection request is received from the connection processing node. Connection request processing step to be performed, and the response received in the connection request processing step does not perform connection processing based on the connection request. The connection request to another connection processing node is transmitted in the connection request processing step, and the connection processing node related to the response is connected for a predetermined period in the transmission destination determination step based on the information included in the response. A control step of excluding the request from the transmission destination of the request, wherein the connection processing node measures the bandwidth usage at the own node by the connection established by the own node, and the connection request from the connection request receiving node A connection request receiving step for receiving a connection request, and determining whether to perform connection processing based on the connection request received in the connection request receiving step based on the bandwidth usage measured in the bandwidth usage measuring step If it is determined in the step and the connection possibility determination step that the connection processing is performed, it is based on the connection request. In addition, when it is determined in the connection processing step for performing the connection processing between the mobile communication terminal and the connection destination and the connection permission determination step in which the connection processing is not performed, the local node is set as the transmission destination of the connection request for a predetermined period. A period notifying step of notifying the connection request receiving node of information to be excluded from the connection request.

  The communication control method according to the present invention is a connection in a communication control system that is included in a mobile communication network and includes a connection request receiving node and a plurality of connection processing nodes connected to the connection request receiving node. A communication control method by a processing node, a bandwidth usage measuring step for measuring bandwidth usage in the own node by a connection established by the own node, a connection request receiving step for receiving a connection request from the connection request receiving node, A connection availability determination step for determining whether to perform connection processing based on the connection request received in the connection request reception step based on the bandwidth usage measured in the bandwidth usage measurement step, and connection when the connection processing is performed When it is determined in the determination step, the connection process between the mobile communication terminal and the connection destination is performed based on the connection request. A period notification for notifying the connection request receiving node of information for excluding the own node from the connection request transmission destination for a predetermined period when it is determined in the connection processing step and the connection permission determination step that the connection processing is not performed. And a step.

  According to the present invention, when the amount of bandwidth used in the connection processing node is so large that there is a risk of reducing the efficiency of connection processing or data transmission / reception via the connection, a new connection processing is performed for a predetermined period. Is not done. Therefore, the bandwidth usage at the connection processing node decreases during that time. Therefore, according to the present invention, it is possible to prevent the usable bandwidth from becoming constricted in the connection processing node in the mobile communication network, and to smoothly transmit and receive data via the mobile communication network.

It is a figure which shows the function structure of the communication control system which concerns on embodiment of this invention. It is an address resolution management table memorize | stored by SGSN. It is a threshold value management table memorize | stored by GGSN. It is a figure which shows the hardware constitutions of SGSN and GGSN contained in the communication control system which concerns on embodiment of this invention. It is a sequence diagram which shows the process (communication control method) performed by the communication control system which concerns on embodiment of this invention. It is a figure which shows another example of a structure of the communication control system which concerns on embodiment of this invention.

  Hereinafter, preferred embodiments of a communication control system, a connection request receiving node, a connection processing node, and a communication control method according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Note that the node name, data name, signal name, and specific contents thereof in this embodiment conform to 3GPP (3rd Generation Partnership Project).

  FIG. 1 shows a communication control system 1 according to the present embodiment. The communication control system 1 is a component of the mobile communication network N1, and is included in the mobile communication network N1. As shown in FIG. 1, the communication control system 1 includes an SGSN 10 and a plurality of GGSNs 20. The mobile communication network N1 also includes a router 30 that interconnects the GGSN 20 and a network other than the mobile communication network N1, such as a PDN (packet data network) N2. The mobile communication network N1 is a connection target of the mobile communication terminal 40 and provides the mobile communication terminal 40 with a mobile communication function. In addition to the above-described components, the mobile communication network N1 includes components that constitute a normal mobile communication network such as a base station, a radio controller, and an HLR (Home Location Register) (not shown).

  As will be described in more detail later, the SGSN 10 is a connection request reception node that receives a connection (communication connection) request from the mobile communication terminal 40 via the mobile communication network N1. The SGSN 10 is connected to a plurality of GGSNs 20 by wire or the like, and transmits the accepted connection request to any of the GGSNs 20 connected to the own node 10. The GGSN 20 is a connection processing node that receives a transmitted connection request and performs connection processing. Although only one SGSN 10 is depicted in FIG. 1, the mobile communication network N1 normally includes a plurality of SGSNs 10. Moreover, although SGSN10 and GGSN20 are demonstrated as one apparatus in this embodiment, you may be implement | achieved as several apparatus (system by a computer).

  The mobile communication terminal 40 is a device possessed by a user and having a function of connecting to the mobile communication network N1 by mobile communication. The mobile communication terminal 40 establishes a connection via mobile communication with the connection destination device by the function of the mobile communication network N1, and transmits / receives data to / from the connection destination device. Establishing the connection means, for example, that a session is established between the mobile communication terminal 40 and the connection destination, and a state where data (user packet) can be transmitted and received.

  The mobile communication terminal 40 has a function of transmitting a connection request (ActivatePDP Context Req.) To the mobile communication network N1 by a user operation or the like in order to establish a connection. The APN information that is information indicating the connection destination is included in the connection request. The APN is determined for each communication service type such as the type of Internet connection service. The function of the mobile communication terminal 40 is the same as that of a conventional mobile communication terminal.

  The PDN (N2) includes a Gi server 50 that can be a connection destination of the mobile communication terminal 40. The Gi server 50 is designated by the above APN.

  Subsequently, functions of the SGSN 10 and the GGSN 20 according to the present invention will be described in detail. As shown in FIG. 1, the SGSN 10 includes a connection request receiving unit 11, a connection request processing unit 12, and a control unit 13.

  The connection request receiving unit 11 receives a connection request (Activate PDP Context Req.) From the mobile communication terminal 40 connected to the mobile communication network N1 via the mobile communication network designating the connection destination. It is. This reception is performed via the constituent elements of the mobile communication network N1, such as a base station and a radio controller (the same applies to the transmission / reception between the mobile communication terminal 40 and the SGSN 10). The connection request receiving unit 11 outputs the received connection request to the connection request processing unit 12.

  The connection request processing unit 12 is a connection request processing unit that processes the connection request received by the connection request receiving unit 11. When a connection request is input from the connection request receiving unit 11, the connection request processing unit 12 selects a GGSN 20 that transmits the connection request from a plurality of GGSNs 20 connected to the own node 10 (address resolution), and selects A connection request (Create PDP Context Req.) Is transmitted to the GGSN 20. The selection of the GGSN 20 is performed based on an address resolution management table stored in advance in the connection request processing unit 12 shown in FIG.

  As shown in FIG. 2, the address resolution management table stores information indicating one or more GGSN 20 addresses (GGSN addresses) in association with information indicating APN. Each GGSN address is associated with information indicating the order of the GGSN 20 at the time of address resolution (information in the column “Selection List” such as Primary and Secondary). The connection request processing unit 12 stores in advance the order of the GGSN 20 that transmits the connection request (for example, transmission to the Secondary next to the Primary, transmission to the Secondary next to the Secondary, etc.).

  Specifically, address resolution is performed as follows. The connection request processing unit 12 refers to the information indicating the APN included in the connection request and the address resolution management table, and specifies a GGSN address to which the connection request can be transmitted. For example, when the APN is “A”, the GGSN addresses that can transmit the connection request are “aaa.aaa.aaa.aaa” (Primary), “bbb.bbb.bbb.bbb” (Secondary), and “Ccc.ccc.ccc.ccc” (Tertiary). The connection request processing unit 12 stores information (Primary, Secondary, etc.) indicating the order associated with the GGSN 20 that has previously transmitted a connection request to the APN, and transmits a connection request based on the order. Select the address of GGSN20.

  As will be described later, when the GGSN address of the GGSN 20 to be excluded from the connection request transmission destination is included in the GGSN addresses that can transmit the connection request, the GGSN address is excluded from the selection.

  The connection request processing unit 12 receives a response (Create PDPContext Res.) To the transmitted connection request from the GGSN 20. If the received response indicates that the connection process with the connection destination has been performed and the connection (session) has been established, a response to the connection request from the mobile communication terminal 40 (ActivatePDP Context Accept) ) To the mobile communication terminal 40.

  On the other hand, when the received response is a notification notifying that the connection process is not performed, that is, a notification notifying that the GGSN 20 is reselected, the information included in the response is output to the control unit 13. The connection request processing unit 12 receives the control from the control unit 13 and transmits the connection request to another GGSN 20. In that case, the above address resolution processing is performed again, and the GGSN 20 is reselected. Also, the connection request processing unit 12 excludes the GGSN 20 that has made a response indicating that the connection processing is not performed, from the connection request transmission destination based on the control from the control unit 13.

  The connection request processing unit 12 includes information indicating the number of GGSNs 20 (number of connection lists) that can be selected as a transmission destination of the connection request and the number of times of connection request transmission (number of connection requests) in the connection request to be transmitted. The number of connection lists is confirmed by referring to the address resolution management table as described above. For example, in the address resolution management table shown in FIG. 2, if the APN is “A”, the number of connection lists is three. When the control for excluding the GGSN 20 from the connection request transmission destination is performed, the number is subtracted from the number of connection lists. The number of connection requests is confirmed by counting the number of transmissions to the GGSN 20 for each connection request. These pieces of information are used to determine whether or not connection processing can be executed in the GGSN 20 as will be described later.

  The control unit 13 is a control unit that controls the connection request processing unit 12 when the response from the GGSN 20 received by the connection request processing unit 12 does not perform connection processing based on the connection request. The control unit 13 causes the connection request processing unit 12 to transmit the connection request to another GGSN 20.

  The information included in the response includes information indicating a period (non-selection time) during which the GGSN 20 that transmitted the response is excluded from the connection request transmission destination. The control unit 13 controls the connection request processing unit 12 to exclude the GGSN 20 from the connection request transmission destination for the period indicated by the information. The period to be excluded is, for example, several seconds as will be described later. The control unit 13 starts control from the time when the information included in the response is received from the connection request processing unit 12, and releases the control when the period elapses (the connection request is also transmitted to the GGSN 20). enable).

  The control part 13 is good also as performing said control according to APN used as a connection destination. That is, when the connection processing based on the connection request is not performed and information indicating the non-selection time is included, only the connection request is excluded from the connection request transmission destination with the same APN as the transmission request as the transmission destination. It is also possible to make it. The above is the functional configuration of the SGSN 10.

  Subsequently, functions of the GGSN 20 according to the present invention will be described in detail. As shown in FIG. 1, the GGSN 20 includes a bandwidth usage measurement unit 21, a connection request reception unit 22, a connection availability determination unit 23, a connection processing unit 24, and a period notification unit 25.

  The bandwidth usage measuring unit 21 is bandwidth usage measuring means for measuring the bandwidth usage in the own node 20 by the connection established by the own node 20. The connection established between the mobile communication terminal 40 and the connection destination is via the GGSN 20. Therefore, data (user packet) transmitted / received using the connection is relayed by the GGSN 20. The bandwidth usage measuring unit 21 monitors, for example, user packets to be relayed and measures the bandwidth usage in the own node 20 (a method including an existing method can be used as the measurement method). The information on the bandwidth usage to be measured is information such as 10 Mbps.

  The measurement by the bandwidth usage measuring unit 21 is performed, for example, at all times (or at regular intervals) so that information on the measured bandwidth usage can be used at all times. The bandwidth usage to be measured is only uplink data (data transmitted from the mobile communication terminal 40 to the connection destination), only downlink data (data transmitted from the connection destination to the mobile communication terminal 40), and uplink / downlink. Any of the sum of the data can be used. The bandwidth usage measuring unit 21 outputs information on the measured bandwidth usage to the connectability determining unit 23 in response to a request. In addition, as described later, when performing control according to the connection destination, the bandwidth usage may be measured for each connection destination (APN).

  The connection request receiving unit 22 is a connection request receiving unit that receives a connection request (Create PDPContext Req.) From the SGSN 10. The connection request reception unit 22 outputs the received connection request to the connection availability determination unit 23.

  The connection availability determination unit 23 determines whether to perform connection processing based on the connection request received by the connection request reception unit 22 based on the bandwidth usage measured by the bandwidth usage measurement unit 21. Means. The connection possibility determination unit 23 stores a threshold value in advance, and the bandwidth usage at the time when the connection request is input from the connection request reception unit 22 (or the latest bandwidth usage measured at that time) and the threshold. And compare. It is assumed that the connection possibility determination unit 23 does not perform the connection process when it is determined that the bandwidth usage exceeds the threshold, and performs the connection processing when it is determined that the bandwidth usage does not exceed the threshold. The above threshold value is set to a value that may cause the GGSN 20 to run out of available bandwidth based on, for example, the capacity of the line, and that data transmission / reception may not be performed smoothly. The threshold value may be set as a ratio to the maximum bandwidth usage determined based on the capacity of the line. Note that, when the determination using the band usage amount is made, the connection possibility determination unit 23 requests and acquires information on the band usage amount from the band usage amount measurement unit 21.

  Further, the above determination may be made according to the connection destination (APN). That is, a threshold is provided for each APN, and the determination may be made based on the bandwidth usage for each APN.

  The connection possibility determination unit 23 compares the number of selection lists indicated by the information included in the connection request with the number of connection requests of the connection request, and if the number of connection requests is equal to or greater than the number of selection lists (or those If the values match), it is determined that the connection process based on the connection request is performed regardless of the determination based on the band usage amount. This is to prevent connection requests from being processed by any GGSN 20. This determination is preferably performed before the determination based on the bandwidth usage in consideration that the determination based on the bandwidth usage is wasted. In this determination, when it is determined that the connection process is to be performed, the determination using the bandwidth usage amount is not performed.

  In addition to the above determinations, the connectability determination unit 23 may determine whether or not to perform connection processing based on the number of established connections and the like as in the conventional method.

  If the connection determination unit 23 determines that connection processing based on the connection request is to be performed based on the above determination, the connection determination unit 23 notifies the connection processing unit 24 and outputs information necessary for the connection processing included in the connection request. To do. On the other hand, when it is determined that the connection process based on the connection request is not performed, the connection availability determination unit 23 notifies the period notification unit 25 to that effect.

  The connection processing unit 24 is a connection processing unit that performs a connection process between the mobile communication terminal 40 and the connection destination based on the connection request when the connection permission determination unit 23 determines that the connection process is performed. As in the conventional method by the connection processing unit 24, the connection between the mobile communication terminal 40 and the connection destination is established by processing such as transmitting a session establishment request to the connection destination based on the information included in the connection request. . When the connection is established, the connection processing unit 24 transmits the fact to the SGSN 10 as a response to the connection request (Create PDP Context Req.).

  The period notification unit 25 notifies the SGSN 10 of information indicating that the node 20 is excluded from the connection request transmission destination for a predetermined period when the connection determination unit 23 determines that the connection process is not performed. Means. This notification is transmitted as a response to the connection request (Create PDP Context Req.). First, the period notification unit 25 includes information indicating that the connection processing related to the response is not performed in the node 20, that is, information for notifying the SGSN 10 to reselect the GGSN 20 in the response.

  Further, the period notification unit 25 includes information indicating a period (non-selection time) in which the own node 20 is excluded from the connection request transmission destination in the response. The period notification unit 25 stores the period in advance. Since no new connection process is performed during this period, the number of connections does not increase. Therefore, based on past statistical data or the like, it is preferable to set a period in which the bandwidth usage of the GGSN 20 is ensured so that data transmission and reception can be performed smoothly. If the period is too short, the bandwidth usage will not be reduced sufficiently, and if the period is too long, the GGSN 20 will not perform a new connection process, so the process of the entire mobile communication network N1 may become inefficient.

  The period may be a uniform time. Alternatively, the period notification unit 25 may determine the non-selection time according to the bandwidth usage measured by the bandwidth usage measuring unit 21. When the bandwidth usage is used to determine the non-selection time, information on the bandwidth usage is input from the connection availability determination unit 23. The determination of the non-selection time is performed based on, for example, a threshold management table stored in advance in the period notification unit 25 shown in FIG. The threshold management table shown in FIG. 3 stores the bandwidth usage threshold and the non-selection time in association with each other. Here, the threshold value of the bandwidth usage is a value of a ratio to the maximum bandwidth usage determined based on the capacity of the line.

  The connectability determination unit 23 determines the bandwidth usage associated with the threshold value that exceeds the bandwidth usage as information to notify the SGSN 10. If a% <b%, the non-selection time is c seconds if the bandwidth usage exceeds only a%, and the non-selection time is d seconds if the bandwidth usage exceeds b%. The Note that any relationship between the threshold and the non-selection time can be used, but it is preferable to increase the non-selection time as the threshold increases. This is because it usually takes a longer time for data to be smoothly transmitted and received when the threshold value is larger. In general, the smallest threshold value (a% in FIG. 3) is preferably matched with the threshold value used for determining whether or not to execute the connection process.

  Further, the above determination may be made according to the connection destination (APN). That is, the determination may be made based on the bandwidth usage for each APN. A threshold management table may be prepared for each APN. The functional configuration of the GGSN 20 has been described above.

  Subsequently, FIG. 4 shows a hardware configuration of the SGSN 10 and the GGSN 20 according to the present embodiment (the SGSN 10 and the GGSN 20 have the same hardware configuration). As shown in FIG. 4, the SGSN 10 and the GGSN 20 include a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102 and a ROM (Read Only Memory) 103, which are main storage devices, a communication module 104, and an auxiliary storage device such as a hard disk. The computer is provided with a hardware having 105 or the like. When these components operate, the above-described functions of the SGSN 10 and the GGSN 20 are exhibited.

  Subsequently, processing (communication control method) executed by the communication control system 1 according to the present embodiment will be described with reference to the sequence diagram of FIG. In the description of this process, a connection request to the PDN (N2) Gi server is made from the mobile communication terminal 40a and the mobile communication terminal 40b. Moreover, GGSN20a and GGSN20b shall be contained in several GGSN20 which can make a connection request | requirement with respect to the connection request.

  In the GGSN 20a and the GGSN 20b, the bandwidth usage measurement unit 21 measures the bandwidth usage in the own nodes 20a and 20b by the connection established by the own nodes 20a and 20b (S01, S02, bandwidth usage measurement step). ). This measurement is always performed (or at regular intervals) as described above.

  A connection request (Activate PDP Context Req.) Specifying the Gi server 50 as a connection destination is transmitted from the mobile communication terminal 40a to the SGSN 10. In the SGSN 10, the connection request reception unit 11 receives the connection request (S03, connection request reception step). The received connection request is output from the connection request receiving unit 11 to the connection request processing unit 12.

  Subsequently, the connection request processing unit 12 refers to the address resolution management table and selects the GGSN 20 that transmits the connection request from the plurality of GGSNs 20 connected to the own node 10 (address resolution) (S04, connection request). Processing steps). Here, GGSN 20a is selected as the transmission destination. Subsequently, the connection request processing unit 12 confirms information indicating the number of GGSNs 20 (number of connection lists) that can be selected as the transmission destination of the connection request and the number of times of transmission of the connection request (number of connection requests) (S05, Connection request processing step). Subsequently, the connection request processing unit 12 includes the connection list (x) and the number of connection requests (y) included in the connection request (Create PDP Context Req.) Based on the connection request from the mobile communication terminal 40a and is selected. Is transmitted to the GGSN 20a (S06, connection request processing step). At this time, the connection request processing unit 12 counts the number of transmissions of the connection request to the GGSN 20.

  In the GGSN 20a, the connection request is received by the connection request receiving unit 22 (S06, connection request receiving step). The received connection request is output from the connection request reception unit 22 to the connection availability determination unit 23. Subsequently, the connection availability determination unit 23 compares the number of selection lists (x) indicated by the information included in the connection request with the number of connection requests (y) of the connection request (S07, connection availability determination step).

  Here, if the number of connection requests is equal to or greater than the number of selection lists, the connection determination unit 23 determines that connection processing based on the connection request is to be performed. When the determination is made in this way, the connection determination unit 23 notifies the connection processing unit 24 of the fact and outputs information necessary for the connection processing included in the connection request. Subsequently, the connection processing unit 24 performs connection processing between the mobile communication terminal 40 and the Gi server 50 that is the connection destination. Specifically, a session establishment request is transmitted from the connection processing unit 24 to the Gi server 50 (S08, connection processing step), and the connection processing unit 24 sends a response to the session establishment request from the Gi server 50. Received (S09, connection processing step). Thereafter, normal connection processing is performed by the connection processing unit 24 (S10, connection processing step).

  On the other hand, if the number of connection requests is not equal to or greater than the number of selection lists in the comparison in S07, the bandwidth usage measuring unit 21 determines whether or not to perform connection processing based on the connection request by the connection possibility determination unit 23. A determination is made based on the measured bandwidth usage (S11, connection possibility determination step). Specifically, the connection availability determination unit 23 compares the bandwidth usage amount with a threshold value stored in advance. When it is determined that the bandwidth usage does not exceed the threshold value, connection processing is performed, and connection processing (S08 to S10) by the connection processing unit 24 is performed in the same manner as described above (not shown).

  When it is determined that the bandwidth usage exceeds the threshold, it is determined that the connection process is not performed, and that is notified from the connection availability determination unit 23 to the period notification unit 25. Subsequently, the non-selection time is determined by the period notification unit 25 (S12, period notification step). As described above, the non-selection time is determined according to the bandwidth usage amount with reference to, for example, the threshold management table shown in FIG. Subsequently, a response (Create PDP Context Req) including information (reselection notification) for notifying the SGSN 10 to reselect the GGSN 20 by the period notification unit 25 and information indicating the non-selection time determined as described above. .) Is generated and transmitted to the SGSN 10 (S13, period notification step).

  In the SGSN 10, the response is received by the connection request processing unit 12 (S13, connection request processing step). Subsequently, the connection request processing unit 12 determines that the response notifies the GGSN 20 to reselect, and outputs information included in the response to the control unit 13.

  Subsequently, the control unit 13 holds the information on the non-selection time corresponding to the GGSN 20a, and the connection request processing unit 12 is configured to exclude the GGSN 20a from the connection request transmission destination during the non-selection time indicated by the information. Control is started (S14, control step). Further, the control unit 13 instructs the connection request processing unit 12 to reselect the GGSN 20 that is the transmission destination of the connection request.

  Subsequently, the connection request processing unit 12 that has received an instruction from the control unit 13 reselects the GGSN 20 that is the transmission destination of the connection request (S15, connection request processing step). The reselection of the GGSN 20 is performed in the same manner as the address resolution process (S04). Here, GGSN20b shall be selected. Subsequently, the connection request processing unit 12 includes the number of connection lists (x) and the number of connection requests (y) in the connection request (Create PDP Context Req.), And transmits the selected GGSN 20b (S16, connection). Request processing step). Here, the information on the number of connection requests included is one larger than the information on the number of times included in the connection request to the GGSN 20a. The number of connection lists is the same as that included in the connection request to the GGSN 20a.

  In the GGSN 20b, the connection request is received by the connection request reception unit 22, and is output to the connection availability determination unit 23 (S16, connection request reception step). Subsequently, as in the above (S07), the connection determination unit 23 performs connection processing based on information on the number of selection lists (x) included in the connection request and the number of connection requests (y) of the connection request. Whether or not execution is possible is determined (S17, connection possibility determination step). Here, if the number of connection requests is not equal to or greater than the number of selection lists, then, similarly to the above (S11), whether or not to perform connection processing based on the connection request is determined by the connection availability determination unit 23. Determination is made based on the bandwidth usage measured by the unit 21 (S18, connection possibility determination step). When it is determined that the bandwidth usage does not exceed the threshold value, the connection process is performed, and the connection process is performed between the connection processing unit 24 and the Gi server in the same manner as (S08 to S10) (S19, connection). Processing steps). When the connection process is completed, the connection processing unit 24 transmits the fact to the SGSN 10 as a response to the connection request (Create PDP Context Res.) (S20, connection process step).

  In the SGSN 10, the response is received by the connection request processing unit 12, and the fact that the connection process with the connection destination has been performed is indicated as a response to the connection request from the mobile communication terminal 40 (Activate PDP Context Accept). 40 (S21, connection request processing step). Thereafter, the connection established between the mobile communication terminal 40a and the Gi server 50 is used to transmit and receive user packets (S22). This transmission / reception is performed via the GGSN 20b and is a measurement target by the band usage measuring unit 21.

  Here, a connection request (Activate PDP Context Req.) Specifying the Gi server 50 as a connection destination is transmitted from the mobile communication terminal 40b different from the mobile communication terminal 40a to the SGSN 10. In the SGSN 10, the connection request reception unit 11 receives the connection request (S31, connection request reception step). The received connection request is output from the connection request receiving unit 11 to the connection request processing unit 12.

  Subsequently, the connection request processing unit 12 refers to the address resolution management table, and the GGSN 20 that transmits the connection request is selected from a plurality of GGSNs 20 connected to the own node 10 (address resolution) (S32, connection request). Processing step, control step). Here, since the connection request processing unit 12 is controlled by the control unit 13 to exclude the GGSN 20a from the connection request transmission destination, the GGSN 20a is excluded from the selection targets. Here, GGSN 20b is selected.

  Similarly to (S05) above, information indicating the number of GGSNs 20 (number of connection lists) that can be selected as the transmission destination of the connection request and the number of transmissions of the connection request (number of connection requests) by the connection request processing unit 12 Is confirmed (not shown). Here, the number of selection lists does not include the above GGSN 20a. Subsequently, the connection request processing unit 12 includes the number of connection lists (x) and the number of connection requests (y) in the connection request (Create PDP Context Req.) And transmits them to the selected GGSN 20b (S33, connection). Request processing step). Subsequent processing is similar to the processing described above (S34).

  When the control unit 13 detects that the non-selection time has elapsed since the control unit 13 started the control for excluding the GGSN 20a from the connection request transmission destination, the control for causing the GGSN 20a to be excluded from the connection request transmission destination is performed. The connection request processing unit 12 can select the GGSN 20a as the connection request transmission destination again. The above is the processing executed by the communication control system 1 according to the present embodiment.

  As described above, in the communication control system 1 according to the present embodiment, the GGSN 20 determines whether or not to perform connection processing based on the connection request based on the bandwidth usage in the own node 20. If this band usage amount is likely to reduce the efficiency of connection processing or data transmission / reception via the connection, or if it is large enough to actually reduce the efficiency, it is determined that the connection processing is not performed. In this case, during the non-selection time, the GGSN 20 notifies the SGSN 10 that the own node 20 is excluded from the connection request transmission destination. When the above notification is made in response to the connection request, the SGSN 10 excludes the GGSN 20 from the connection request transmission destination during the non-selection time.

  That is, in the communication control system 1 according to the present embodiment, the bandwidth usage in the GGSN 20 may decrease the efficiency of connection processing or data transmission / reception via the connection, or is actually large enough to decrease the efficiency. In some cases, no new connection processing is performed during the non-selection time. Therefore, the bandwidth usage in the GGSN 20 decreases during that time (however, since the user packet is transmitted / received through the connection established through the GGSN 20 at that time, the bandwidth usage may increase) is there).

  In addition, the connection process is selected and transmitted with priority from the GGSN 20 that allows user packets to communicate smoothly. Therefore, according to the communication control system 1 according to the present embodiment, efficient use of equipment in the mobile communication network N1 can be realized, and the available bandwidth in the GGSN 20 can be prevented from becoming tight, and the mobile communication network N1 can be configured. The data can be transmitted and received smoothly. That is, compared to the mobile communication network N1, connection delays and discarding of user packets are reduced in the conventional case. In addition, since the number of retransmitted user packets is reduced, it contributes to an early leveling of the band tight condition, and the processing load on the facility can be reduced.

  In addition, as in the present embodiment, it is desirable that the non-selection time is determined according to the measured bandwidth usage using the threshold management table shown in FIG. According to this configuration, the period during which no new connection processing is performed in the GGSN 20 can be made appropriate according to the bandwidth usage. As a result, it is possible to prevent the bandwidth usage amount from becoming excessively long and appropriately prevent the available bandwidth in the GGSN 20 from becoming tight.

  Further, as in this embodiment, the connection request (CreatePDP Context Req.) Transmitted from the SGSN 10 to the GGSN 20 includes the number of connection lists and the number of connection requests, and determines whether or not to perform connection processing based on the information. It is desirable. According to this configuration, it is possible to prevent the occurrence of a situation in which connection processing is not performed in all of the GGSNs 20 that can be selected as the connection request transmission destination in the SGSN 10, and to reliably perform connection processing in any of the GGSNs 20. be able to.

  Further, as described above, it is desirable to determine whether or not connection processing can be performed for each APN, or to determine a non-selection time. According to this configuration, it is possible to perform appropriate processing according to the APN. However, when there is no difference in the GGSN 20 according to the APN or when there is no difference in the total bandwidth usage by the GGSN 20 according to the APN, it is not necessary to perform the above.

  In the present embodiment, the connection request receiving node is described as SGSN 10 and the connection processing node is described as GGSN 20. However, these devices are not necessarily required. The present invention is applicable to any communication control system in which one connection request receiving node selects a connection processing node from a plurality of connection processing nodes and performs connection processing.

  For example, the present invention can be applied to a GGSN 60 as shown in FIG. The GGSN 60 receives a connection request from the SGSN 70 and performs connection processing. The GGSN 60 includes a C-Plane processing device 61 that is one connection request receiving node that receives a connection request, and a U-Plane processing device 62 that is connected to the C-Plane processing device 61 and is actually connected. It is comprised including. Each U-Plane processing device 62 has a different physical configuration.

  The C-Plane processing device 61 and the U-Plane processing device 62 have the same configuration as the SGSN 10 and the GGSN 20 described above for the processing for the connection request. That is, the C-Plane processing device 61 has a configuration corresponding to the connection request receiving unit 11, the connection request processing unit 12, and the control unit 13, and the U-Plane processing device 62 is configured to use the bandwidth usage measuring unit 21. And a connection request reception unit 22, a connection availability determination unit 23, a connection processing unit 24, and a period notification unit 25. The present invention can be applied even in the case of the above configuration.

  DESCRIPTION OF SYMBOLS 1 ... Communication control system, 10 ... SGSN, 11 ... Connection request reception part, 12 ... Connection request process part, 13 ... Control part, 20 ... GGSN, 21 ... Bandwidth usage measurement part, 22 ... Connection request reception part, 23 ... Connection possibility determination unit, 24 ... connection processing unit, 25 ... period notification unit, 101 ... CPU, 102 ... RAM, 103 ... ROM, 104 ... communication module, 105 ... auxiliary storage device, 30 ... router, 40 ... mobile communication terminal, 50 ... Gi server, 60 ... GGSN, 61 ... C-Plane processing device, 62 ... U-Plane processing device, N1 ... Mobile communication network, N2 ... PDN.

Claims (8)

A communication control system included in a mobile communication network, comprising a connection request receiving node and a plurality of connection processing nodes connected to the connection request receiving node,
The connection request receiving node is:
A connection request receiving means for receiving a connection request via a mobile communication network designating a connection destination from a mobile communication terminal connected to the mobile communication network;
A connection processing node that transmits the connection request received by the connection request accepting unit is selected from the plurality of connection processing nodes, and a connection request is transmitted to the selected connection processing node and a response to the connection request is transmitted. Connection request processing means received from the connection processing node;
When the response received by the connection request processing means does not perform connection processing based on the connection request, the connection request processing means transmits the connection request to another connection processing node and Control means for excluding the connection processing node related to the response from the destination of the connection request for a predetermined period based on the information included in the response,
The connection processing node
Bandwidth usage measuring means for measuring bandwidth usage in the own node by connection established by the own node;
Connection request receiving means for receiving the connection request from the connection request receiving node;
A connection availability determination unit that determines whether to perform connection processing based on the connection request received by the connection request reception unit, based on the bandwidth usage measured by the bandwidth usage measurement unit;
A connection processing means for performing connection processing between the mobile communication terminal and the connection destination based on the connection request when the connection processing is determined by the connection permission determination means;
A period notifying unit for notifying the connection request receiving node of information for excluding the own node from a connection request transmission destination for a predetermined period when it is determined by the connection enable / disable determining unit that the connection process is not performed; Comprising
A communication control system characterized by that.   2. The communication control system according to claim 1, wherein the period notifying unit of the connection processing node determines the predetermined period according to the band usage measured by the band usage measuring unit. The connection request processing means of the connection request receiving node transmits information indicating the number of connection processing nodes that can be selected as the transmission destination of the connection request and the number of times of transmission of the connection request to the selected connection processing node. Include in the request
The connection possibility determination unit of the connection processing node includes the number of connection processing nodes that can be selected as a transmission destination of the connection request indicated by information included in the connection request received by the connection request reception unit, and the connection If the number of transmissions of the connection request is equal to or greater than the number of connection processing nodes that can be selected as the transmission destination of the connection request by comparing with the number of transmissions of the request, regardless of the determination based on the bandwidth usage Determine that connection processing based on the connection request is to be performed,
The communication control system according to claim 1 or 2. The connection request processing means of the connection request receiving node selects a connection processing node that transmits the connection request from the plurality of connection processing nodes according to a connection destination specified by the connection request,
The control means of the connection request receiving node excludes the connection processing node related to the response from the connection request transmission destination for a predetermined period with respect to the transmission destination determination means according to the connection destination specified by the connection request. Let
The bandwidth usage measuring means of the connection processing node measures the bandwidth usage according to the connection destination,
The connection availability determination unit determines whether to perform connection processing based on the connection request received by the connection request reception unit, according to a connection destination.
The communication control system according to any one of claims 1 to 3.   The communication control system according to claim 1, wherein the period notifying unit of the connection processing node determines the predetermined period according to the connection destination. The connection processing node in a communication control system, which is included in a mobile communication network and includes a connection request receiving node and a plurality of connection processing nodes connected to the connection request receiving node,
Bandwidth usage measuring means for measuring bandwidth usage in the own node by connection established by the own node;
Connection request receiving means for receiving the connection request from the connection request receiving node;
A connection availability determination unit that determines whether to perform connection processing based on the connection request received by the connection request reception unit, based on the bandwidth usage measured by the bandwidth usage measurement unit;
A connection processing means for performing connection processing between the mobile communication terminal and the connection destination based on the connection request when the connection processing is determined by the connection permission determination means;
A period notifying unit for notifying the connection request receiving node of information for excluding the own node from a connection request transmission destination for a predetermined period when it is determined by the connection enable / disable determining unit that the connection process is not performed; ,
A connection processing node comprising: A communication control method by a communication control system that is included in a mobile communication network and includes a connection request receiving node and a plurality of connection processing nodes connected to the connection request receiving node,
The connection request receiving node is
A connection request receiving step for receiving a connection request via a mobile communication network designating a connection destination from a mobile communication terminal connected to the mobile communication network;
The connection processing node that transmits the connection request received in the connection request reception step is selected from the plurality of connection processing nodes, the connection request is transmitted to the selected connection processing node, and a response to the connection request is transmitted. A connection request processing step received from the connection processing node;
If the response received in the connection request processing step does not perform connection processing based on the connection request, the connection request is sent to another connection processing node in the connection request processing step and A control step of excluding the connection processing node related to the response from the transmission destination of the connection request for a predetermined period in the transmission destination determination step based on information included in the response,
The connection processing node is
A bandwidth usage measuring step for measuring bandwidth usage in the local node by the connection established by the local node;
A connection request receiving step for receiving the connection request from the connection request receiving node;
A connection availability determination step of determining whether to perform connection processing based on the connection request received in the connection request reception step, based on the bandwidth usage measured in the bandwidth usage measurement step;
A connection processing step for performing connection processing between the mobile communication terminal and the connection destination based on the connection request when it is determined in the connection permission determination step when the connection processing is performed;
A period notifying step for notifying the connection request receiving node of information indicating that the local node is excluded from a connection request transmission destination for a predetermined period when it is determined in the connection permission determination step that the connection processing is not performed; ,including,
A communication control method characterized by the above. A communication control method by the connection processing node in a communication control system that is included in a mobile communication network and includes a connection request receiving node and a plurality of connection processing nodes connected to the connection request receiving node,
A bandwidth usage measuring step for measuring bandwidth usage in the local node by the connection established by the local node;
A connection request receiving step for receiving the connection request from the connection request receiving node;
A connection availability determination step of determining whether to perform connection processing based on the connection request received in the connection request reception step, based on the bandwidth usage measured in the bandwidth usage measurement step;
A connection processing step for performing connection processing between the mobile communication terminal and the connection destination based on the connection request when it is determined in the connection permission determination step when the connection processing is performed;
A period notifying step for notifying the connection request receiving node of information indicating that the local node is excluded from a connection request transmission destination for a predetermined period when it is determined in the connection permission determination step that the connection processing is not performed; ,
The communication control method characterized by including.

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