The present invention relates to a communication system, and more particularly to a communication system that selects a communication control device from a plurality of communication control devices.
Background technology
[0002]
　With the spread of smartphones and tablet terminals, MMEs (Mobile Management Entity) located in the core network must process a wide variety of signalings generated by applications of these devices. In addition, the characteristics change greatly depending on the time or place where communication occurs, such as the provision of MTC (Machine Type Communication) services, the implementation of crowded events, or the occurrence of disasters, and the number of unpredictable signaling increases. ing. In such an environment, mobile carriers must maintain quality of service while curbing overinvestment and reducing total cost of ownership (TCO).
[0003]
　Therefore, the MME is required to have a mechanism for dynamically distributing the signaling load according to the performance of the device, the possessed resources, the load status, and the like. For example, Non-Patent Document 1 discloses a mechanism of signaling control in MME. Further, Patent Document 1 describes that the load is distributed by changing the accommodation to another MME in units of eNB (evolved NodeB) in order to avoid congestion of the MME.
Prior art literature
Patent documents
[0004]
Patent Document 1: Japanese Patent Application Laid-Open No. 2014-533011
Non-patent literature
[0005]
Non-Patent Document 1: 3GPP TS 23.401 V13.1.0 (2014-12) 5.3.2 Attach procedure
Outline of the invention
Problems to be solved by the invention
[0006]
　However, in Non-Patent Document 1, once information necessary for call processing such as MM Context (subscriber data) regarding a communication terminal is generated in a specific MME, when performing call processing regarding that communication terminal, Describes that it will continue to use the MME for which the information required for call processing has been generated. Therefore, in the call processing, there is a problem that the MME to be used cannot be dynamically changed according to the load status of the MME or the like. Further, Patent Document 1 has a problem that the load balancing of MME may not be sufficiently performed or may not be performed appropriately because the accommodation is changed in units of eNB.
[0007]
　An object of the present invention is to provide a communication system, a communication control device, a node device, and a communication method capable of solving the above problems and more effectively distributing the load of the MME.
Means to solve problems
[0008]
　The communication system according to the first aspect of the present invention is a communication system including a plurality of communication control devices and a node device that executes control processing including call processing related to the plurality of communication control devices and communication terminals. The plurality of communication control devices form a context sharing group that shares subscriber data of the communication terminal, and the node device selects a first communication control device in the context sharing group, and the first communication control device is selected. A call processing message is transmitted to the communication control device, and the first communication control device executes call processing using the subscriber data shared in the context sharing group.
[0009]
　The communication control device according to the second aspect of the present invention receives a call processing message from a context sharing unit that shares subscriber data of a communication terminal with another communication control device belonging to a context sharing group, and a node device. The call processing is executed using the subscriber data shared in the context sharing group.
[0010]
　The node device according to the third aspect of the present invention is a node device that executes control processing including call processing related to the communication control device and the communication terminal, and each time a call processing message is transmitted, subscriber data of the communication terminal is executed. One communication control device is selected from a plurality of communication control devices belonging to the context sharing group that shares the above, and a control processing message including a call processing message is transmitted to the selected communication control device.
[0011]
　The communication method according to the fourth aspect of the present invention is executed in a communication system including a plurality of communication control devices and a node device that executes control processing including call processing related to the plurality of communication control devices and communication terminals. In a communication method, the plurality of communication control devices form a context sharing group that shares subscriber data of the communication terminal, and the node device selects a first communication control device in the context sharing group. Then, a call processing message is transmitted to the selected first communication control device, and the first communication control device executes call processing using the subscriber data shared in the context sharing group. be.
The invention's effect
[0012]
　INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a communication system, a communication control device, a node device, and a communication method capable of more effectively distributing the load of the MME according to the load status of the MME and the like.
A brief description of the drawing
[0013]
FIG. 1 is a configuration diagram of a communication system according to a first embodiment.
FIG. 2 is a configuration diagram of a communication system according to a second embodiment.
FIG. 3 is a configuration diagram of an MME according to a second embodiment.
FIG. 4 is a configuration diagram of an eNB according to a second embodiment.
FIG. 5 is a configuration diagram of S-GW according to the second embodiment.
FIG. 6 is a configuration diagram of an HSS according to a second embodiment.
FIG. 7 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the eNB according to the second embodiment.
FIG. 8 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the eNB according to the second embodiment.
FIG. 9 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the eNB according to the second embodiment.
FIG. 10 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the S-GW according to the second embodiment.
FIG. 11 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the S-GW according to the second embodiment.
FIG. 12 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the S-GW according to the second embodiment.
FIG. 13 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the S-GW according to the second embodiment.
FIG. 14 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the S-GW according to the second embodiment.
FIG. 15 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the HSS according to the second embodiment.
FIG. 16 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the HSS according to the second embodiment.
FIG. 17 is a diagram showing a flow of notification processing of information regarding a context sharing group from the MME to the HSS according to the second embodiment.
FIG. 18 is a diagram showing management information managed by eNB, S-GW, and HSS according to the second embodiment.
FIG. 19 is a diagram showing a call process according to the second embodiment.
FIG. 20 is a diagram showing a call process according to the second embodiment.
FIG. 21 is a diagram showing a flow of notification processing of information regarding a context sharing group for an eNB when an MME according to the third embodiment is added.
FIG. 22 is a diagram showing a flow of notification processing of information regarding a context sharing group for S-GW when the MME according to the third embodiment is added.
FIG. 23 is a diagram showing a flow of notification processing of information regarding a context sharing group for S-GW when the MME according to the third embodiment is added.
FIG. 24 is a diagram showing a flow of notification processing of information regarding a context sharing group for S-GW when the MME according to the third embodiment is added.
FIG. 25 is a diagram showing a flow of notification processing of information regarding a context sharing group for an eNB when the MME according to the third embodiment is reduced.
FIG. 26 is a diagram showing a flow of notification processing of information regarding a context sharing group for an eNB when the MME according to the fourth embodiment is reduced.
FIG. 27 is a diagram showing a flow of notification processing of information regarding a context sharing group for S-GW when the MME according to the fourth embodiment is reduced.
FIG. 28 is a diagram showing a flow of notification processing of information regarding a context sharing group for S-GW when the MME according to the fourth embodiment is reduced.
FIG. 29 is a diagram showing a flow of notification processing of information regarding a context sharing group for S-GW when the MME according to the fourth embodiment is reduced.
FIG. 30 is a diagram showing a flow of notification processing of information regarding a context sharing group for HSS when the MME according to the fourth embodiment is reduced.
FIG. 31 is a diagram showing a flow of notification processing of information regarding a context sharing group for HSS when the MME according to the fourth embodiment is reduced.
FIG. 32 is a diagram showing a flow of notification processing of information regarding a context sharing group for an eNB when the WF of the MME according to the fifth embodiment is changed.
FIG. 33 is a diagram illustrating an interface related to HSS according to the sixth embodiment.
FIG. 34 is a diagram illustrating an interface related to HSS according to the sixth embodiment.
FIG. 35 is a diagram showing a flow of storage processing of Contact information according to the sixth embodiment.
FIG. 36 is a diagram showing a flow of storage processing of Contact information according to the sixth embodiment.
FIG. 37 is a configuration diagram of a communication system according to a seventh embodiment.
Mode for carrying out the invention
[0014]
　(Embodiment 1)
　Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a configuration example of the communication system according to the first embodiment of the present invention will be described with reference to FIG. The communication system of FIG. 1 has communication control devices 10 to 12 and a node device 20. In this figure, it is shown that the node device 20 is connected to the communication control devices 10 to 12, but the node device 20 may be connected to two or three or more communication control devices.
[0015]
　The communication control devices 10 to 12 may be computer devices that are operated by the CPU (Central Processing Unit) executing a program stored in the memory. Further, the communication control devices 10 to 12 may be MME or SGSN (Serving GPRS Support Node) specified in 3GPP (3rd Generation Partnership Project).
[0016]
　The node device 20 executes a control process including a call process related to the communication terminal between the communication control devices 10 and 12. The call processing corresponds to, for example, control processing such as route setting in a core network, which is executed when a communication terminal makes a voice call, data communication, or the like. The node device 20 may be a computer device that is operated by the CPU (Central Processing Unit) executing a program stored in the memory. Further, the node device 20 may be an eNB (evolved Node B), an RNC (Radio Network Controller), an S-GW (Serving Gateway), an HSS (Home Subscriber Server), or the like specified in 3GPP.
[0017]
　The communication terminal may be, for example, a mobile phone, a smartphone, a tablet terminal having a communication function, or the like. Further, the communication terminal may be a computer device such as a personal computer.
[0018]
　The communication control devices 10 to 12 form a context sharing group that shares the subscriber data of the communication terminal. Sharing subscriber data means that the subscriber data that can be used by the communication control device 10 can also be used by the communication control devices 11 and 12. For example, when there is a server device that manages subscriber data, communication control devices 10 to 12 may appropriately acquire subscriber data from the server device. Alternatively, the subscriber data held in the other communication control device may be acquired by transmitting and receiving the subscriber data between the respective communication control devices.
[0019]
　When the node device 20 executes call processing or control processing related to the communication terminal, the node device 20 selects any communication control device in the context sharing group. Further, the node device 20 transmits a call processing message or a control message to the selected communication control device. The call processing message may be, for example, a control message specified in 3GPP. In 3GPP, various control messages such as an Attack Request message transmitted when the power of the communication terminal transitions to the ON state are defined. The node device is the information notified from the communication control device (for example, the congestion status of each communication control device, the capacity of each communication control device, and the subscriber data (context sharing group) shared between the communication control devices). Select a communication controller based on information, etc.).
[0020]
　The communication control device selected by the node device 20, that is, the call processing message transmitted from the node device 20, or the communication control device that receives the control message, calls processing using the subscriber data shared in the context sharing group. Or, execute the control process. For example, when the communication control device selected in the node device 20 holds the subscriber data of the communication terminal to be called in its own device, the call processing is performed using the held subscriber data. Alternatively, control processing is executed. If the communication control device selected in the node device 20 does not hold the subscriber data of the communication terminal to be called in its own device, even if it acquires the subscriber data managed in the server device. Often, subscriber data may be acquired from other communication control devices.
[0021]
　As described above, by using the communication system of FIG. 1, the communication control device belonging to the context sharing group can share the subscriber data of the communication terminal. Therefore, the node device can execute the call processing or the control processing of the communication terminal regardless of which communication control device belongs to the context sharing group.
[0022]
　As a result, the node device 20 can dynamically change the communication control device that communicates when executing the call processing or the control processing. Therefore, the node device 20 can change the communication control device according to, for example, the load status of the communication control device. As a result, the node device 20 can perform load balancing control in a plurality of communication control devices. Further, the node device can distribute a call processing message or a control message to each subscriber to the communication control device that shares the subscriber data. Therefore, as compared with the case where the message is distributed to the node device unit, the node device can more appropriately distribute the message to the communication control device in a fine unit.
[0023]
　(Embodiment 2)
　Subsequently, a configuration example of the communication system according to the second embodiment of the present invention will be described with reference to FIG. The communication system of FIG. 2 is composed of the devices specified in 3GPP. The communication system of FIG. 2 has MME30-60, eNB70, HSS80, S-GW90, P-GW (Packet Data Network-Gateway) 100 and UE (User Equipment) 110. MMEs 30 to 60 correspond to the communication control device of FIG. The eNB 70, HSS 80 and S-GW 90 correspond to the node device of FIG. The UE 110 corresponds to a communication terminal.
[0024]
　Further, MME may be replaced with SGSN specified in 3GPP, and eNB may be replaced with RNC specified in 3GPP.
[0025]
　In this figure, MME30 and MME40 belong to the context sharing group A, and MME50 and MME60 belong to the context sharing group B. Further, MMEs 30 to 60 may belong to an MME group which is a group different from the context sharing group. The MME group is a group to which the candidate MME to which the eNB 70 first generates Context information belongs. The Context information corresponds to the subscriber data described in FIG. That is, the MME group may include a plurality of context sharing groups. Alternatively, the MME belonging to the MME group and the MME belonging to the context sharing group may be the same.
[0026]
　In general, if the eNB 70 first decides to generate Context information about the UE 110 in the MME 30, it will select the MME 30 in all subsequent call processing. On the other hand, in each embodiment of the present application, the eNB 70 can select the MME 30 or the MME 40 in the subsequent call processing even when the Context information is first generated in the MME 30. Further, the HSS80 and the S-GW 90 can also select an MME different from the MME from which the Context information was first generated and execute the call processing.
[0027]
　Subsequently, a configuration example of the MME 30 according to the second embodiment of the present invention will be described with reference to FIG. Since the MMEs 40 to 60 have substantially the same configuration as the MME 30, detailed description thereof will be omitted.
[0028]
　The MME 30 has a Diameter communication unit 31, an S1AP (S1 Application) communication unit 32, a GTP (General packet radio service Tunneling Protocol) -C communication unit 33, a Context sharing unit 34, a Context storage unit 35, and an MME call processing unit 36. ing. The Diameter communication unit 31 is used as an interface with the HSS 80. The S1AP communication unit 32 is used as an interface with the eNB 70. The GTP-C communication unit 33 is used as an interface with the S-GW 90.
[0029]
　The Contact sharing unit 34 acquires the Contact information of the UE 110 that is the target of the call processing. For example, when the Context information generated in the MME of the context sharing group A is managed in the server device or the like, the Context sharing unit 34 may acquire the Context information of the UE 110 to be called from the server device. good. Alternatively, the Context sharing unit 34 may acquire the Context information of the UE 110 to be called from the MME 40 belonging to the context rejection group A.
[0030]
　The Context storage unit 35 stores the Context information acquired by the Context sharing unit 34 and the Context information generated in the MME 30. The Contact storage unit 35 may be, for example, a memory in the MME 30, an external memory device mounted on the MME 30, or the like. Alternatively, the Context information may be shared among the plurality of MMEs by the HSS 80 holding the Context information and accessing it as needed by a plurality of MMEs.
[0031]
　Further, the Context storage unit 35 holds information about the context sharing group to which the MME 30 belongs. Here, the Context storage unit 35 holds information indicating the context sharing group A. The Contact storage unit 35 may be, for example, a memory in the MME 30, an external memory device mounted on the MME 30, or the like. Alternatively, the information held by the Context storage unit 35 may be shared among the plurality of MMEs by the HSS 80 holding the Context storage unit 35 and being accessed by a plurality of MMEs as needed.
[0032]
　The MME call processing unit 36 ​​executes call processing using the Context information stored in the Context storage unit 35 and the information indicating the context sharing group A. The MME call processing unit 36 ​​transmits and receives a message related to call processing to and from the eNB 70, HSS 80, or S-GW 90 via the Diameter communication unit 31, the S1AP communication unit 32, or the GTP-C communication unit 33.
[0033]
　Subsequently, a configuration example of the eNB 70 according to the second embodiment of the present invention will be described with reference to FIG. The eNB 70 has an S1AP communication unit 71, an S1AP call processing unit 72, an RRC (Radio Resource Control) processing unit 73, a radio processing unit 74, a GTP-U communication unit 75, a GTP-U processing unit 76, and a Context storage unit 77. ing.
[0034]
　The S1AP communication unit 71 is used as an interface when communicating with the MMEs 30 to 60. The S1AP call processing unit 72 executes call processing between the MMEs 30 and 60 by using the information stored in the Context storage unit 77.
[0035]
　The S1AP call processing unit 72 sends and receives a message related to call processing between the MMEs 30 and 60 via the S1AP communication unit 71. Further, the S1AP call processing unit 72 selects an MME to perform call processing using the information stored in the Context storage unit 77.
[0036]
　The RRC (Radio Resource Control) processing unit 73 executes processing related to the RRC protocol used with the UE 110. For example, the RRC processing unit 73 may execute a process of managing the connection state with the UE 110. The wireless processing unit 74 is used as an interface for wireless communication with the UE 110.
[0037]
　The GTP-U communication unit 75 is used as an interface when communicating with the S-GW 90. The GTP-U processing unit 76 transmits / receives user data to / from the S-GW 90 via the GTP-U communication unit 75.
[0038]
　The Contact storage unit 77 stores information about the context sharing group transmitted from the MMEs 30 to 60. For example, the Context storage unit 77 stores the context sharing group and the MME belonging to the group in association with each other. Further, the Context storage unit 77 may store the WF (Weight Factor) referred to when selecting each MME in association with the MME.
[0039]
　Subsequently, a configuration example of the S-GW 90 according to the second embodiment of the present invention will be described with reference to FIG. The S-GW 90 has a GTP-C communication unit 91, a GTP-U communication unit 92, a GTP-C processing unit 93, a Context storage unit 94, and a GTP-U processing unit 95.
[0040]
　The GTP-C communication unit 91 is used as an interface when communicating with the MMEs 30 to 60. The GTP-U communication unit 92 is used as an interface when communicating with the eNB 70.
[0041]
　The GTP-C processing unit 93 transmits and receives a message related to call processing between the MMEs 30 and 60 via the GTP-C communication unit 91. Further, the GTP-C processing unit 93 selects an MME to perform call processing using the information stored in the Context storage unit 94. The GTP-U processing unit 95 transmits / receives user data to / from the eNB 70 via the GTP-U communication unit 92.
[0042]
　The Contact storage unit 94 stores information about the context sharing group transmitted from the MMEs 30 to 60. For example, the Context storage unit 77 stores the context sharing group and the MME belonging to the group in association with each other. Further, the WF referred to when selecting each MME may be stored in association with the MME.
[0043]
　Subsequently, a configuration example of the HSS 80 according to the second embodiment of the present invention will be described with reference to FIG. The HSS 80 has a Diameter communication unit 81, a subscriber information processing unit 82, and a subscriber information storage unit 83. The Diameter communication unit 81 is used as an interface when communicating with the MMEs 30 to 60.
[0044]
　The subscriber information storage unit 83 stores information about the context sharing group transmitted from the MMEs 30 to 60. For example, the subscriber information storage unit 83 stores the context sharing group and the MME belonging to the group in association with each other. Further, the subscriber information storage unit 83 may store the WF referred to when selecting each MME in association with the MME.
[0045]
　The subscriber information processing unit 82 sends and receives a message related to call processing between the MMEs 30 and 60 via the Diameter communication unit 81. Further, the subscriber information processing unit 82 selects an MME to perform call processing using the information stored in the subscriber information storage unit 83.
[0046]
　Subsequently, the flow of notification processing of information regarding the context sharing group from the MME to the eNB according to the second embodiment of the present invention will be described with reference to FIG. 7. First, the eNB 70 sends an S1 SETUP REQUEST message to all MMEs in the MME group in order to establish an S1 connection (S11).
[0047]
　Next, each MME sends an S1 SETUP RESPONSE message to the eNB 70 in response to the S1 SETUP REQUEST message (S12). Each MME sets the context sharing group to which its own device belongs, GUMMEI (Globally Unique MME Identifier) ​​and WF (Weight Factor) in the S1 SETUP RESPONSE message. GUMMEI is identification information for uniquely identifying the MME. The WF is priority information used by the eNB 70 when selecting an MME to execute call processing. For example, the eNB 70 may select an MME having a high WF value more times and select an MME having a low WF value less frequently. The eNB 70 holds the information set in the S1 SETUP RESPONSE message.
[0048]
　Subsequently, with reference to FIG. 8, the flow of the notification processing different from that of FIG. 7 will be described with respect to the notification processing of the information regarding the context sharing group according to the second embodiment of the present invention. First, the MME 30 and the MME 40 carry out a representative selection process for determining which is the representative MME (S20). The representative selection process is executed among a plurality of MMEs belonging to the same context sharing group. For example, as the representative MME, an MME in which the younger identification information is set may be selected, or a representative MME may be selected according to other criteria. Here, it is assumed that the MME 30 is selected as the representative MME. Further, in the representative selection process, the MME 40 or the like that is not the representative MME may transmit information such as GUMMEI and WF of its own device to the representative MME.
[0049]
　Next, the eNB 70 sends an S1 SETUP REQUEST message to all MMEs in the MME group in order to establish an S1 connection (S21). Note that FIG. 8 shows that the eNB 70 is transmitting the S1 SETUP REQUEST message to the MME 30 and the MME 40, but it is said that the S1 SETUP REQUEST message is transmitted to all the MMEs in the MME group. do.
[0050]
　Next, the representative MME, the MME 30, transmits an S1 SETUP RESPONSE message in which the context sharing group, the GUMMEI of all the MMEs belonging to the context sharing group, and the WF of all the MMEs are set to the eNB 70 (S22). .. The MME 40, which is not the representative MME, sends an S1 SETUP RESPONSE message to the eNB 70 in order to establish an S1 connection. Information about the context sharing group may not be set in the S1 SETUP RESPONSE message transmitted by the MME 40.
[0051]
　Subsequently, with reference to FIG. 9, the flow of notification processing different from that of FIGS. 7 and 8 will be described with respect to the notification processing of the information regarding the context sharing group according to the second embodiment of the present invention. In this figure, the EMS (Element Management System) device registers information on the context sharing group, the GUMMEI of all MMEs belonging to the context sharing group, and the WF of all MMEs in the eNB 70 (S31).
[0052]
　Subsequently, with reference to FIG. 10, the flow of notification processing of information regarding the context sharing group from the MME to the S-GW according to the second embodiment of the present invention will be described. First, each MME transmits a GTP Echo REQUEST message in which the context sharing group to which the own device belongs and the WF are set to the S-GW 90 (S41). The S-GW 90 identifies the MME using the IP address of the source of the GTP Echo REQUEST message. The S-GW 90 holds the information set in the GTP Echo REQUEST message.
[0053]
　Next, the S-GW 90 transmits a GTP Echo RESPONSE message to each MME (S42). Generally, the GTP Echo REQUEST message and the GTP Echo RESPONSE message are used to confirm whether or not a failure has occurred between the MME and the S-GW.
[0054]
　Subsequently, with reference to FIG. 11, the flow of the notification processing different from that of FIG. 10 will be described with respect to the notification processing of the information regarding the context sharing group according to the second embodiment of the present invention. In this figure, the S-GW 90 transmits a GTP Echo REQUEST message to each MME (S51). Next, each MME transmits a GTP Echo RESPONSE message in which the context sharing group to which the own device belongs and the WF are set to the S-GW 90 (S52).
[0055]
　Subsequently, with reference to FIG. 12, the flow of the notification processing different from that of FIGS. 10 and 11 will be described with respect to the notification processing of the context sharing group information according to the second embodiment of the present invention.
[0056]
　First, the MME 30 and the MME 40 carry out a representative selection process for determining which is the representative MME (S60). The representative selection process is executed among a plurality of MMEs belonging to the same context sharing group. Here, it is assumed that the MME 30 is selected as the representative MME.
[0057]
　Next, the representative MME, the MME 30, transmits a GTP Echo REQUEST message in which the WFs of the context sharing group and all the MMEs belonging to the context sharing group are set to the S-GW 90 (S61). The MME 30 may be set by associating the IP address, which is the identification information of the MME belonging to the context sharing group, with the WF. The MME 40, which is not the representative MME, transmits a normal GTP Echo REQUEST message to the S-GW 90 (S62).
[0058]
　Next, the S-GW 90 transmits a GTP Echo RESPONSE message to each MME as a response message to the GTP Echo REQUEST message (S63).
[0059]
　Subsequently, with reference to FIG. 13, the flow of the notification processing different from that of FIGS. 10 to 12 will be described with respect to the notification processing of the context sharing group information according to the second embodiment of the present invention. First, the MME 30 and the MME 40 carry out a representative selection process in the same manner as in step S60 of FIG. 12 (S70). Next, the S-GW 90 transmits a GTP Echo REQUEST message to all MMEs in the MME group (S71).
[0060]
　Next, the representative MME, the MME 30, transmits a GTP Echo REQUEST message in which the WFs of the context sharing group and all the MMEs belonging to the context sharing group are set as a response message to the GTP Echo REQUEST message to the S-GW 90 (S72). ..
[0061]
　The MME 40, which is not the representative MME, transmits a normal GTP Echo RESPONSE message to the S-GW 90 as a response message to the GTP Echo REQUEST message (S73).
[0062]
　Subsequently, with reference to FIG. 14, the flow of the notification processing different from that of FIGS. 10 to 13 will be described with respect to the notification processing of the context sharing group information according to the second embodiment of the present invention. In this figure, the EMS (Element Management System) device registers information on the WF of the context sharing group and all MMEs belonging to the context sharing group with the S-GW 90 (S81).
[0063]
　Subsequently, the flow of the notification processing of the context sharing group information from the MME to the HSS80 according to the second embodiment of the present invention will be described with reference to FIG. First, each MME establishes an SCTP (Stream Control Transmission Protocol) Connection with the HSS80 (S90).
[0064]
　Next, each MME sends an Update Context Shared Group REQUEST message to the HSS 80 in which the context sharing group to which the own device belongs, Origin-Host, and WF are set (S91). Origin-Host is information that identifies the MME. The HSS80 holds the information set in the Update Context Shared Group REQUEST message.
[0065]
　Next, the HSS 80 sends an Update Context Shared Group ANSWER message to each MME in response to the Update Context Shared Group REQUEST message (S92).
[0066]
　Subsequently, with reference to FIG. 16, the flow of the notification processing different from that of FIG. 15 will be described with respect to the notification processing of the context sharing group information according to the second embodiment of the present invention. First, MME30 and MME40 establish SCTP Connection in the same manner as in step S90 of FIG. 15 (S100). Next, the MME 30 and the MME 40 carry out a representative selection process for determining which is the representative MME (S101). The representative selection process is executed among a plurality of MMEs belonging to the same context sharing group. Here, it is assumed that the MME 30 is selected as the representative MME.
[0067]
　Next, the representative MME, MME30, sends an Update Context Shared Group REQUEST message to the HSS80, which sets the Origin-Host of the context sharing group, all the MMEs belonging to the context sharing group, and the WF of all the MMEs belonging to the context sharing group. (S102). Next, the HSS 80 sends an Update Context Shared Group ANSWER message to the MME 30 as a response to the Update Context Shared Group REQUEST message (S103).
[0068]
　Subsequently, with reference to FIG. 17, the flow of the notification processing different from that of FIGS. 15 and 16 will be described with respect to the notification processing of the context sharing group information according to the second embodiment of the present invention. In this figure, the EMS (Element Management System) device registers the WF of the context sharing group and all the MMEs belonging to the context sharing group with the HSS80 (S111).
[0069]
　In FIGS. 7 to 17, the eNB 70, S-GW 90, and HSS 80 that have received the information about the context sharing group manage the information about the context sharing group as shown in FIG. The management information shown in FIG. 18 is managed by associating the context sharing group with the MME belonging to the context sharing group. Further, the WF value set in the MME is also managed in association with each MME. MME30 to MME # N belong to the context sharing group A, and MME50 and MME60 belong to the context sharing group B. Further, for example, MME30 belongs to the context sharing group A, and it is shown that the value of WF is 50.
[0070]
　Further, the information for identifying the MME may differ depending on the type of node. For example, the eNB may use GUMMEI as the identification information of the MME, the SGW may use the IP address as the identification information of the MME, and the HSS may use Origin-Host.
[0071]
　Subsequently, the flow of the call processing according to the second embodiment of the present invention will be described with reference to FIGS. 19 and 20. First, the UE 110 transmits a NAS (Non-Access Stratum): Attach REQUEST message to the eNB 70 when the power button is pressed by the user and the device is started (S121). The UE 110 sets the GUTI (Globally Unique Temporary Identifier) ​​in the NAS: Attach REQUEST message. GUTI is information composed of GUMMEI and M-TMSI (Temporary Mobile Subscriber Identity). GUTI is temporary identification information used to uniquely identify the UE.
[0072]
　Next, the eNB 70 performs a process of selecting an MME for transmitting a NAS: Attach REQUEST message (S122). The eNB 70 identifies the GUMMEI from the GUTI set in the NAS: Attach REQUEST message in the process of selecting the MME. The GUMMEI identified from the GUTI indicates the MME that generated the Context information about the UE 110 in the previous Attach process, or the MME selected by the eNB. From the management information shown in FIG. 18, the eNB 70 can identify the context sharing group to which the MME identified by GUMMEI belongs. The eNB 70 selects an MME according to the WF from among the MMEs belonging to the specified context sharing group. In this figure, it is assumed that MME30 is selected as eNB70.
[0073]
　Next, the eNB 70 sends a NAS: Attach REQUEST / S1AP: Initial UE message to the selected MME (S123). Next, the MME 30 selects an Authentication Information REQUEST message to the HSS 80 in order to acquire an authentication vector (AV) relating to the UE 110 (S124). Next, the HSS 80 performs a process of selecting the MME to be the destination of the Authentication Information ANSWER message in which the AV is set (S125). The HSS 80 uses the management information shown in FIG. 18 to identify the context sharing group to which the MME 30 that has sent the Authentication Information REQUEST message belongs. The HSS80 selects an MME according to the WF from among the MMEs belonging to the specified context sharing group. In this figure, it is assumed that MME # N is selected for HSS80. It is assumed that MME # N is included in the same context sharing group A as MME30.
[0074]
　Next, the HSS 80 sends an Authentication Information ANSWER message to the selected MME # N (S126). In this way, the HSS 80 can send the Authentication Information ANSWER message to the MME # N different from the MME 30 that has sent the Authentication Information REQUEST message. Next, MME # N sends an Authentication REQUEST message to the eNB 70 (S127).
[0075]
　Moving on to FIG. 20, the MME 30 sends a Create Session REQUEST message to the S-GW 90 in order to generate a session with the S-GW 90 (S128). Next, the S-GW 90 performs a process of selecting the MME to be the destination of the Create Session RESPONSE message (S129). The S-GW 90 uses the management information of FIG. 18 to identify the context sharing group to which the MME 30 that has sent the Create Session REQUEST message belongs. The S-GW 90 selects an MME according to the WF from the MMEs belonging to the specified context sharing group. In this figure, it is assumed that MME # N is selected for S-GW90.
[0076]
　Next, the S-GW 90 sends a Create Session RESPONSE message to the selected MME # N (S130). In this way, the S-GW 90 can send the Create Session RESPONSE message to the MME # N different from the MME 30 that has sent the Create Session REQUEST message.
[0077]
　Next, MME # N sends a NAS: Attach Accept / S1AP: Initial Context Setup Request message to the eNB 70 (S131). In step S131, the eNB 70 can receive the NAS: Attach Accept message from the MME # N different from the MME 30 that sent the NAS: Attach Request message.
[0078]
　Next, the eNB 70 transmits a NAS: Attach Accept message to the UE 110 (S132). Next, in step S131, when the eNB 70 receives the S1AP: Initial Context Setup REQUEST message, it performs a process of selecting the MME to be the destination of the S1AP: Initial Context Setup RESPONSE message (S133). Here, it is assumed that the eNB 70 selects MME # N from the context sharing group A. Next, the eNB 70 sends an S1AP: Initial Context Setup RESPONSE message to the selected MME # N. In this way, the eNB 70 can transmit the S1AP: Initial Context Setup RESPONSE message to the MME # N different from the MME 30 which is the destination of the NAS: Attach REQUEST message transmitted in step S123.
[0079]
　Next, MME # N transmits a Modify Bearer REQUEST message to the S-GW 90 (S135). Next, the S-GW 90 performs the same process as in step S129 in order to select the MME for transmitting the Modify Bearer RESPONSE message (S136). Here, it is assumed that S-GW 90 selects MME30. Next, the S-GW 90 sends a Modify Bearer RESPONSE message to the selected MME30.
[0080]
　As described above, the MME can share the Context information about the UE with other MMEs in the same context sharing group. Therefore, even if a call processing message is transmitted from the eNB, S-GW, and HSS to any MME in the context sharing group, the call processing to the UE can be continued.
[0081]
　Further, the node devices around the MME, eNB, S-GW, and HSS, can send a call processing message to any MME in the context sharing group when performing the call processing of the UE. Therefore, the eNB, S-GW, and HSS can distribute the load of call processing executed in the MME.
[0082]
　(Embodiment 3)
　Subsequently, with reference to FIG. 21, a flow of notification processing of context sharing group information from the MME to the eNB when the MME according to the third embodiment of the present invention is added will be described.
[0083]
　First, after adding an MME, another MME in the context sharing group to which the added MME belongs sends an S1 SETUP request message requesting the activation of the S1 SETUP message to the eNB 70 (S151). In this figure, the additional MME belongs to the context sharing group A, and the MME 30 in the context sharing group A transmits the S1 SETUP request message to the eNB 70.
[0084]
　After that, the process of FIG. 7 or FIG. 8 is executed, and the eNB 70 receives the information about the context sharing group set in the S1 SETUP RESPONSE message.
[0085]
　The MME that sends the S1 SETUP request message may be, for example, an MME selected as a representative before the additional MME belongs to the context sharing group, or an MME in which information about the additional MME is input from an administrator or the like. May be good. Further, when the representative selection process is executed between the expansion MME and the existing MME and the expansion MME is selected as the representative MME, the expansion MME may send an S1 SETUP request message.
[0086]
　Further, instead of the MME transmitting the S1 SETUP request message, the EMS apparatus may register the information regarding the additional MME in the eNB 70 as shown in FIG. When the information about the additional MME is registered, the eNB 70 may send the S1 SETUP REQUEST message to all the MMEs or only the additional MMEs as shown in FIGS. 7 and 8.
[0087]
　Subsequently, with reference to FIG. 22, a flow of notification processing of context sharing group information from the MME to the S-GW when the MME according to the third embodiment of the present invention is added will be described. First, the expansion MME transmits a GTP Echo REQUEST message in which the context sharing group to which the own device belongs and the WF are set to the S-GW 90 (S161).
[0088]
　The S-GW 90 manages the information shown in FIG. 18, and by receiving the GTP Echo REQUEST message, the information related to the additional MME is added to the information shown in FIG. 18 to update the management information (S162). Next, the S-GW 90 transmits a GTP Echo RESPONSE message to the expansion MME (S163).
[0089]
　Subsequently, with reference to FIG. 23, regarding the flow of notification processing of context sharing group information from the MME to the S-GW when the MME according to the third embodiment of the present invention is added, a processing flow different from that of FIG. 22. explain.
[0090]
　First, when the MME is added, the selection process of the representative MME is executed in the context sharing group to which the added MME belongs (S171). Here, it is assumed that MME # N is selected as the representative MME. Next, the representative MME sends a GTP Echo REQUEST message to the S-GW 90 in which the WFs of the context sharing group and all the MMEs belonging to the context sharing group are set (S172).
[0091]
　Since steps S173 and S174 are the same as steps S162 and S163 in FIG. 22, detailed description thereof will be omitted. However, in step S174, the S-GW 90 transmits a GTP Echo REQUEST message to the representative MME.
[0092]
　Subsequently, using FIG. 24, the flow of notification processing of the context sharing group information from the MME to the S-GW when the MME according to the third embodiment of the present invention is added is different from that of FIGS. 22 and 23. The flow of is explained.
[0093]
　Since step S181 is the same as step S171 in FIG. 23, detailed description thereof will be omitted. Next, the S-GW 90 transmits a GTP Echo REQUEST message to all MMEs in the MME group (S182). Next, the representative MME transmits a GTP Echo RESPONSE message in which the WFs of the context sharing group and all the MMEs belonging to the context sharing group are set to the S-GW 90 (S183). Here, for MMEs other than the representative MME, a GTP Echo RESPONSE message that does not set information such as a context sharing group may be transmitted to the S-GW 90. Since step S184 is the same as step S173 in FIG. 23, detailed description thereof will be omitted.
[0094]
　Further, instead of using the GTP Echo REQUEST message and the GTP Echo RESPONSE message as shown in FIGS. 22 to 24, the EMS apparatus may register the information regarding the expansion MME in the S-GW 90 as shown in FIG. Further, instead of using the GTP Echo REQUEST message and the GTP Echo RESPONSE message as shown in FIGS. 22 to 24, information on the expansion MME is transmitted to the S-GW 90 using a new message that is not currently defined in 3GPP. May be good.
[0095]
　Subsequently, the flow of the notification processing of the context sharing group information from the expansion MME to the HSS according to the third embodiment of the present invention will be described. When MME is added, SCTP Connection is established between the added MME and HSS80 as in FIGS. 15 and 16. After the SCTP Connection is established, the Update Context Shared Group REQUEST message is used to notify the HSS of information such as a context sharing group related to the added MME, as in FIGS. 15 and 16.
[0096]
　As described above, when the MME is added, the eNB 70, S-GW 90 and HSS 80 can grasp that the MME has been added and update the management information. The eNB 70, S-GW 90, and HSS 80 can perform call processing using the added MME by selecting the added MME according to the value of the WF. That is, the eNB 70, S-GW 90, and HSS 80 can dynamically transmit a call processing message to the added MME.
[0097]
　(Embodiment 4)
　Subsequently, the flow of information update processing of the eNB 70 in the case where the MME according to the fourth embodiment of the present invention is reduced with reference to FIG. 25 will be described. First, the MME to be reduced starts the reduction process (S191). The MME reduction process may be, for example, turning off the power of the MME or shutting down the MME.
[0098]
　When the MME performs the reduction process, the S1AP connection between the reduced MME and the eNB 70 is disconnected. At this time, the eNB 70 detects that the connection of S1AP is disconnected (S192). Next, the eNB 70 updates the management information by deleting the information regarding the reduced MME from the management information described with reference to FIG. 18 (S193). At this time, if the only MME belonging to the context sharing group is the reduced MME, the eNB 70 may also disconnect the RRC connection.
[0099]
　In this figure, the case where the MME is reduced has been described, but the processing in this figure may be applied even when a failure occurs in the MME.
[0100]
　Subsequently, with reference to FIG. 26, the flow of the information update processing of the eNB 70 in the case where the MME according to the fourth embodiment of the present invention is reduced will be described with respect to the flow of the information update processing different from that of FIG. 25. The MME to be reduced sends an MME Shutdown Indication message to the eNB 70 before starting the reduction process (S201). The MME to be reduced sends an MME Shutdown Indication message to the eNB 70 to notify that the reduction process is started. Also, the MME Shutdown Indication message may be a message with a different name.
[0101]
　The MME to be reduced may set the context sharing group, GUMMEI, and shutdown time in the MME Shutdown Indication message. The shutdown time is, for example, information indicating the time when the MME to be reduced starts the reduction process, or how many seconds later the MME starts the reduction process. In this way, by transmitting the shutdown time to the eNB 70 by the MME to be reduced, for example, it is possible to prevent call loss due to the sudden reduction of the MME. For example, the eNB 70 that has received the MME Shutdown Indication message may prioritize the call processing with the MME to be reduced.
[0102]
　Subsequently, with reference to FIG. 27, the flow of the information update processing of the S-GW 90 in the case where the MME according to the fourth embodiment of the present invention is reduced will be described. The S-GW 90 periodically sends a GTP Echo REQUEST message to the MME to confirm that it is normally connected to the MME (S211). However, when the MME is reduced, the S-GW 90 does not receive a response signal to the transmitted GTP Echo REQUEST message. Therefore, the S-GW 90 repeats the transmission of the GTP Echo REQUEST message (S212).
[0103]
　Next, if the S-GW 90 does not receive the response message even after repeating the transmission of the GTP Echo REQUEST message a predetermined number of times, it determines that the MME has been reduced or a failure has occurred in the MME. In this case, the S-GW 90 updates the management information of FIG. 18 and deletes the entry of the MME determined to have been reduced or a failure has occurred (S213).
[0104]
　Subsequently, with reference to FIG. 28, the flow of the information update processing of the S-GW 90 in the case where the MME according to the fourth embodiment of the present invention is reduced will be described as a processing flow different from that of FIG. 27. The MME to be reduced sends a GTP Echo REQUEST message set to be reduced to the S-GW 90 before starting the reduction (S221). The MME to be reduced may set, for example, a context sharing group to which the MME to be reduced belongs and a reduction flag indicating the reduction as a new IE (Information Element) in the GTP Echo REQUEST message. ..
[0105]
　Next, when the S-GW 90 receives the GTP Echo REQUEST message in step S221, it updates the management information of FIG. 18 and deletes the entry of the MME to be reduced (S222). Next, the S-GW 90 transmits a GTP Echo RESPONSE message to the MME to be reduced (S223).
[0106]
　Subsequently, with reference to FIG. 29, the flow of the information update processing of the S-GW 90 in the case where the MME according to the fourth embodiment of the present invention is reduced will be described as a processing flow different from that of FIGS. 27 and 28. .. In FIG. 28, the MME to be reduced has been informed to the S-GW 90 that it will be reduced by sending a GTP Echo REQUEST message, but in FIG. 29, the MME Shutdown Indication message is sent to the S-GW 90. Tell them to shut down by sending. The MME to be reduced may set a context sharing group and a shutdown time in the MME Shutdown Indication message. The shutdown time is, for example, information indicating the time when the MME to be reduced starts the reduction process, or how many seconds later the MME starts the reduction process.
[0107]
　Next, when the S-GW 90 receives the MME Shutdown Indication message in step S221, it updates the management information of FIG. 18 and deletes the entry of the MME to be reduced (S232). Here, the S-GW 90 ends the process without transmitting a response message to the MME Shutdown Indication message.
[0108]
　Further, instead of using the GTP Echo REQUEST message and the MME Shutdown Indication message as shown in FIGS. 27 to 29, the EMS apparatus may register the information regarding the reduced MME in the S-GW 90 as shown in FIG. Further, instead of using the GTP Echo REQUEST message and the MME Shutdown Indication message as shown in FIGS. 27 to 29, information on the reduced MME is transmitted to the S-GW 90 using a new message that is not currently defined in 3GPP. You may.
[0109]
　Subsequently, with reference to FIG. 30, the flow of the information update processing of the HSS 80 when the MME according to the fourth embodiment of the present invention is reduced will be described. First, the MME to be reduced starts the reduction process (S241). The MME reduction process may be, for example, turning off the power of the MME or shutting down the MME.
[0110]
　When the MME performs the reduction process, the TCPP connection between the reduced MME and the HSS80 is disconnected. At this time, the HSS 80 detects that the TCP connection is disconnected (S242). Next, the HSS 80 deletes the information regarding the reduced MME from the management information described in FIG. 18 and updates the management information (S243).
[0111]
　Subsequently, with reference to FIG. 31, the flow of the information update processing of the HSS 80 in the case where the MME according to the fourth embodiment of the present invention is reduced will be described with respect to the flow of the information update processing different from that of FIG. 30. The MME to be reduced sends an MME Shutdown Indication message to the HSS 80 before starting the reduction process (S252). The MME to be reduced sends an MME Shutdown Indication message to the HSS 80 to notify that the reduction process is started. Also, the MME Shutdown Indication message may be a message with a different name.
[0112]
　The MME to be reduced may set the context sharing group, Origin-Host, and shutdown time in the MME Shutdown Indication message. The shutdown time is, for example, information indicating the time when the MME to be reduced starts the reduction process, or how many seconds later the MME starts the reduction process. In this way, by transmitting the shutdown time to the eNB 70 by the MME to be reduced, for example, it is possible to prevent call loss due to the sudden reduction of the MME. For example, the HSS 80 that has received the MME Shutdown Indication message may prioritize the call processing with the MME to be reduced.
[0113]
　Next, the MME to be reduced starts the reduction process at the timing indicated in the shutdown time (S252). Further, the HSS 80 updates the management information by deleting the MME to be reduced from the management information entry shown in FIG.
[0114]
　As described above, when the MME is reduced, the eNB 70, S-GW 90, and HSS 80 can grasp that the MME has been reduced and can update the management information. After updating the management information, the eNB 70, S-GW 90, and HSS 80 will not send a call processing message to the reduced MME.
[0115]
　Normally, when the MME is reduced, the MME to be reduced needs to transfer the Context information of each UE held by the MME to another MME. In such a case, in general, the MME causes the UE to detach, causes the UE to perform the Attach process again, and causes the new MME to generate the context information of the UE. Here, when the UE being communicated is detached, there is a problem that the communication of the UE being communicated is temporarily interrupted.
[0116]
　On the other hand, in the communication system according to the fourth embodiment, each MME can share the Context information stored in an external server device or the like. Therefore, it is not necessary to detach the UE even when the MME is reduced. From this, by using the communication system according to the fourth embodiment, it is possible to reduce the number of MMEs without interrupting the communication of the UE.
[0117]
　Further, when the Context information is stored in the server device or the like, the Context information is not deleted even when the MME is reduced. Therefore, the remaining MME can continue the call processing by using the Context information stored in the server device or the like instead of the reduced MME.
[0118]
　(Embodiment 5)
　Subsequently, the flow of information update processing of the HSS 80 when the MME according to the fifth embodiment of the present invention is scaled up or down will be described with reference to FIG. 32. Scale-up of MME is to improve the performance of MME, and scale-down of MME is to reduce the performance of MME. When the MME is scaled up, the call processing amount in the scaled up MME can be increased. In such a case, the scaled-up MME raises the value of WF to increase the chance that the own device is selected in the peripheral node device. When the MME is scaled down, the scaled-down MME lowers the value of the WF to reduce the chance that the own device is selected in the peripheral node device. In FIG. 32, the flow of processing when notifying the eNB 70 of the WF changed by scale-up or scale-down will be described.
[0119]
　First, it is assumed that MME # N belonging to the context sharing group A is scaled up or down (S261). Next, MME # N sends an MME Configuration Update message to the eNB 70 (S262). MME # N sets the values ​​of the context sharing group, GUMMEI, and the updated WF in the MME Configuration Update message.
[0120]
　Next, the eNB 70 updates the WF value of MME # N in the management information shown in FIG. 18 (S263). Next, the eNB 70 sends an MME Configuration Update Acknowledge message to MME # N.
[0121]
　Further, in this figure, an example in which the MME # N whose WF has been changed sends the MME Configuration Update message to the eNB 70 has been described, but the representative MME in the context sharing group A sends the MME Configuration Update message to the eNB 70. May be good. In this case, the representative MME may set the context sharing group and the GUMMEI and WF of all MMEs in the context sharing group in the MME Configuration Update message. Alternatively, the representative MME may set the context sharing group, the GUMMEI of the MME that updated the WF, and the updated WF in the MME Configuration Update message.
[0122]
　Further, as shown in FIG. 9, the EMS apparatus may register the information regarding the updated WF of MME # N in the eNB 70.
[0123]
　Subsequently, the flow of the information update processing of the S-GW 90 when the MME is scaled up or down will be described. When the MME is scaled up or down, the updated WF is set in the GTP Echo REQUEST message or the GTP Echo RESPONSE message in the same manner as in the processes shown in FIGS. 10 to 13. Alternatively, as in the process in FIG. 14, the EMS apparatus may register the updated WF of the MME scaled up or down to the S-GW 90.
[0124]
　Subsequently, the flow of the information update processing of the HSS 80 when the MME is scaled up or down will be described. When the MME is scaled up or down, the MME sets the updated WF in the Update Context Shared Group REQUEST message as in the processing in FIGS. 15 and 16. Alternatively, similar to the process in FIG. 17, the EMS apparatus may register information about the updated WF of the MME scaled up or down to the HSS80.
[0125]
　As described above, by using the communication system according to the fifth embodiment of the present invention, the load balancing control of the MME can be dynamically performed according to the change in the performance of the MME.
[0126]
　Further, the WF may be changed when congestion occurs in the MME. For example, when congestion occurs in the MME, the WF of the MME in which the congestion has occurred may be changed to a low value. By doing so, the peripheral node devices have less chance to select the MME, and congestion can be avoided.
[0127]
　(Embodiment 6)
　Subsequently, with reference to FIGS. 33 and 34, a configuration in the case where the MME in the context sharing group uses the HSS80 as a device for storing the Context information in order to share the Context information will be described. ..
[0128]
　FIG. 33 shows that the MME 30 is connected to the HSS 80 via the S6a interface. In this figure, it is shown that the MME 30 is connected to the HSS 80, but a plurality of MMEs are connected to the HSS 80 via the S6a interface.
[0129]
　FIG. 34 shows that the MME 30 is connected to the HSS-FE (Front End) 85 via the S6a interface and is connected to the UDR (User Data Repository) 86 via the Ud interface. Further, the HSS-FE85 is connected to the UDR86 via the Ud interface.
[0130]
　The UDR86 holds the subscriber data of the UE. Further, the HSS-FE85 is arranged between the MME30 and the UDR86, and relays the communication between the MME30 and the UDR86. In this way, the configuration of the HSS 80 may be separated into a UDR 86 which is a data storage unit and an HSS-FE 85 which operates as an interface when communicating with the MME 30.
[0131]
　Subsequently, the flow of the process of storing the Context information created in the MME in the HSS80 or UDR86 will be described with reference to FIGS. 35 and 36.
[0132]
　First, the eNB 70 selects the MME to which the NAS: Attach REQUEST message is sent, as in step S122 and the like in FIG. 19 (S271). Here, it is assumed that the eNB 70 has selected the MME 30. Next, the eNB 70 transmits a NAS: Attach REQUEST message to the selected MME 30 (S272).
[0133]
　Next, the MME 30 generates Context information regarding the UE that has transmitted the NAS: Attach REQUEST message (S273). For example, the MME 30 generates the Context information when the Context information regarding the UE that has transmitted the NAS: Attach REQUEST message is not stored in the HSS 80.
[0134]
　Next, the MME 30 transmits a Context Put REQUEST message in order to store the generated Context information in the HSS80 or UDR86 (hereinafter referred to as HSS80 or the like) (S275). Next, the HSS80 or the like stores the Context information set in the Context Put REQUEST message in the memory or the like of its own device (S275). Next, HSS80 and the like send a Context Put ANSWER message to MME30. Here, the HSS80 or the like does not execute the process of selecting an arbitrary MME in the context sharing group, but sends the Context Put ANSWER message to the MME that has sent the Context Put REQUEST message.
[0135]
　Next, the MME 30 transmits an Authentication Information REQUEST message to the HSS 80 or the like in order to acquire the authentication vector (AV) required to authenticate the UE (S277). Next, the HSS 80 or the like sends an Authentication Information Answer message set with the authentication vector of the designated UE to the MME 30 (S278).
[0136]
　Next, the MME 30 transmits a Context Put REQUEST message to the HSS 80 or the like in order to transmit the authentication vector transmitted from the HSS 80 or the like to the HSS 80 or the like. The HSS80 or the like updates the Context information by reflecting the authentication vector of the UE in the Context information stored in step S275 (S280). Next, the HSS 80 transmits a Context Put ANSWER message to the MME 30 (S281).
[0137]
　Next, the MME 30 transmits an Authentication REQUEST message to the UE via the eNB 70 in order to authenticate the UE (S282). Next, the eNB 70 selects the destination MME in the same manner as in step S271 in order to transmit the Authentication RESPONSE message (S283). Here, it is assumed that the eNB 70 selects MME # N belonging to the context sharing group A.
[0138]
　Next, the eNB 70 sends an Authentication RESPONSE message to the selected MME # N (S284).
[0139]
　Proceeding to FIG. 36, MME # N sends a Context Get REQUEST message to HSS80 or the like in order to acquire the Context information regarding the UE (S285). Next, the HSS80 or the like sends a Context Get ANSWER message in which the Context information of the specified UE is set to MME # N (S286).
[0140]
　Next, MME # N executes an authentication process related to the UE (S287). Next, MME # N sends a Context Put REQUEST message in which the Context information is set in the HSS 80 in order to store the Context information reflecting the authentication process in the HSS 80 or the like (S288). Next, HSS80 and the like update the current Context information by using the Context information set in the Context Put REQUEST message (S289). Next, HSS80 and the like send a Context Put ANSWER message to MME # N (S290).
[0141]
　Here, steps S277 to S281 in FIG. 35 are operations of acquiring the authentication vector required for authenticating the UE from the HSS and further storing the authentication vector in the Context stored in the HSS 80. Therefore, when the HSS80 or the like executes the operation of saving the authentication vector in the stored Contex information, steps S277 to S281 can be omitted.
[0142]
　As described above, by using the communication system according to the sixth embodiment of the present invention, the HSS can store the Context information generated in the MME. As a result, a plurality of MMEs belonging to the context sharing group can use the Context information generated in other MMEs by acquiring the Context information from the HSS.
[0143]
　(Embodiment 7)
　Subsequently, a configuration example of the communication system according to the seventh embodiment of the present invention will be described with reference to FIG. 37. The communication system of FIG. 37 differs from the communication system of FIG. 2 in the MME belonging to the context sharing group. In this figure, the points different from the communication system of FIG. 2 will be mainly described.
[0144]
　In the communication system of this figure, MME30 and MME40 belong to the context sharing group C. Further, MME40, MME50 and MME60 belong to the context sharing group D. That is, the MME 40 belongs to the context sharing group C and the context sharing group D. In this way, the MME may belong to a plurality of context sharing groups.
[0145]
　In the context sharing group configuration as shown in FIG. 37, when the call processing of FIG. 19 is executed, the eNB 70 indicates which context the MME 40 is when the GUMMEI specified from the GUTI set in the NAS: Attach REQUEST message indicates the MME 40. It is not possible to specify whether it belongs to a shared group.
[0146]
　Therefore, in such a case, information that can identify the context sharing group may be set in GUMMEI. For example, the MMEC area of ​​GUMMEI may be subdivided into MMEC + context sharing group ID. Alternatively, after the eNB 70 sends the NAS: Attach REQUEST message to the MME 40, the context sharing group may be specified in the message sent from the MME.
[0147]
　As described above, as in the communication system according to the seventh embodiment of the present invention, by allowing the MME to belong to a plurality of context-sharing groups, the MMEs belonging to the plurality of context-sharing groups are respectively. It can also be used as an alternative device in the context sharing group of.
[0148]
　The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit.
[0149]
　Although the invention of the present application has been described above with reference to the embodiments, the invention of the present application is not limited to the above. Various changes that can be understood by those skilled in the art can be made within the scope of the invention in the configuration and details of the invention of the present application.
[0150]
　This application claims priority on the basis of Japanese application Japanese Patent Application No. 2015-049573 filed on March 12, 2015, and the entire disclosure thereof is incorporated herein by reference.
Code description
[0151]
　10 Communication control device
　11 Communication control device
　12 Communication control device
　20 Node device
　30 MME
　31 Diameter communication unit
　32 S1AP communication unit
　33 GTP-C communication unit
　34 Contact sharing unit
　35 Contact storage unit
　36 MME Call processing unit
　40 MME
　50 MME
　60 MME
　70 eNB
　71 S1AP communication unit
　72 S1AP call processing unit
　73 RRC processing unit
　74 Radio processing unit
　75 GTP-U communication unit
　76 GTP-U processing unit
　77 Context storage unit
　80 HSS
　81 Diameter communication unit
　82 Subscriber Information processing unit
　83 Subscriber Information storage unit
　85 HSS-FE
　86 UDR
　90 S-GW
　91 GTP-C communication unit
　92 GTP-U communication unit
　93 GTP-C processing unit
　94 Context storage unit
　95 GTP-U processing unit
　100 P-GW
　110 UE
The scope of the claims
[Claim 1]
　A communication system including a plurality of communication control devices, the plurality of communication control devices, and a node device that executes call processing related to the communication terminal, and the
　plurality of communication control devices share subscriber data of the communication terminal. The
　node device
　selects the first communication control device in the context sharing group, sends a call processing message to the first communication control device, and controls
　the first communication. The device is a
　communication system that executes call processing using the subscriber data shared in the context sharing group.
[Claim 2]

　The communication system according to claim 1, wherein 　each communication control device belonging to the context sharing group transmits an identifier of the context sharing group to which the own device belongs and an identifier of the own device to the node device.
[Claim 3]

　The communication system according to claim 2, wherein 　each communication control device belonging to the context sharing group further transmits weight information indicating a priority for selecting its own device to the node device.
[Claim 4]

　The communication according to claim 1, wherein the 　representative communication control device belonging to the context sharing group transmits the identifier of the context sharing group to which the own device belongs and the identifiers of all the communication control devices belonging to the context sharing group to the node device. system.
[Claim 5]
　The representative communication control device belonging to the
　context sharing group further transmits weight information indicating a priority for selecting each call control device to the node device for all communication control devices belonging to the context sharing group. 4. The communication system according to 4.
[Claim 6]

　The communication system according to claim 1, 　wherein the node device receives an identifier of the context sharing group and an identifier of all communication control devices belonging to the context sharing group transmitted from a management device that manages the network.
[Claim 7]

　The communication system according to claim 6, 　wherein the management device further transmits weight information indicating a priority for selecting each call control device to the node device for all communication control devices belonging to the context sharing group.
[Claim 8]
　The communication terminal
　transmits an identifier of a communication control apparatus that has performed the previous communication to the node device,
　the node device,
　wherein the communication terminal identifies the shared context group including call control apparatus executed the previous communication, the specific The communication system according to any one of claims 2 to 7, wherein the call processing message is transmitted to a communication control device selected from a plurality of communication control devices belonging to the context sharing group.
[Claim 9]
　The communication terminal
　transmits the identifier of the context sharing group to which the communication control device that has previously communicated belongs to the node device, and the
　node device
　communicates selected from a plurality of communication control devices belonging to the context sharing group. The communication system according to any one of claims 2 to 7, wherein the call processing message is transmitted to the control device.
[Claim 10]
　The node device
　identifies the context sharing group to which the call control device that has transmitted the call processing message belongs, and sends the call processing message to the communication control device selected from the plurality of communication control devices belonging to the specified context sharing group. The communication system according to any one of claims 2 to 7, wherein a response message to the above is transmitted.
[Claim 11]
　The node device
　deletes the second communication control device from the context sharing group when it detects that the connection with the second communication control device belonging to the context sharing group is disconnected. 10. The communication system according to any one of 10.
[Claim 12]

　Each time the 　node device transmits a call processing message , the node device selects one of the communication control devices from a plurality of communication control devices belonging to the context sharing group, and transmits the call processing message to the selected communication control device. The communication system according to any one of claims 1 to 11.
[Claim 13]
　The third communication control device scheduled to stop the operation
　transmits a message indicating that the own device stops the operation to the node device, and the
　node device
　shares the third communication control device with the context. The communication system according to any one of claims 1 to 12, which is deleted from the group.
[Claim 14]

　The communication system according to claim 13, 　wherein the third communication control device sets information indicating a timing at which the operation is stopped in a message indicating that the own device stops the operation.
[Claim 15]
　When a
　call processing message is received from a context sharing means that shares subscriber data of a communication terminal with another communication control device belonging to the context sharing group and a node device , the subscriber data shared in the context sharing group is used. A communication control device that executes call processing.
[Claim 16]
　A node device that executes call processing related to a communication control device and a communication terminal, and
　one of a plurality of communication control devices belonging to a context sharing group that shares subscriber data of the communication terminal each time a call processing message is transmitted. A node device that selects a communication control device and sends a call processing message to the selected communication control device.
[Claim 17]
　A communication method executed in a communication system including a plurality of communication control devices, the plurality of communication control devices, and a node device that executes call processing related to the communication terminal,
　wherein the plurality of communication control devices are the communication terminals. A context sharing group is formed to share the subscriber data of the
　above, the node device selects the first communication control device in the context sharing group,
　and sends a call processing message to the selected first communication control device. and,
　the first communication control unit executes the call processing by using the subscriber data to be shared in the context sharing group, the communication method.