JP6025232B1 - Mobile communication system, MME, communication method, and program - Google Patents

Abstract

To provide a mobile communication system in which a UE can normally hand over from a 3GPP communication area to a Non-3GPP communication area even after resumption of HSS. A mobile communication system according to the present invention includes a PGW that establishes a PDN connection used for communication with a mobile communication terminal, an HSS that holds a PGW ID that is an identifier of the PGW, and a mobility management of the mobile communication terminal. The mobility management device 100 receives the Tracking Area Update message transmitted from the mobile communication terminal 10, and updates the PGW ID set regardless of the PGW ID holding state in the HSS 12. A Location Request message is transmitted to the HSS 12. [Selection] Figure 1

Description

  The present invention relates to a mobile communication system, a mobility management device, a communication method, and a program, and more particularly, to a mobile communication system, a mobility management device, a communication method, and a program that execute a handover process.

  In 3GPP (3rd Generation Partnership Project), a communication area (3GPP communication area) in which a wireless communication method specified in 3GPP is used and a communication area (Non-3GPP communication area) in which a wireless communication method not specified in 3GPP is used A method related to a handover for continuously providing a service to the Internet is being studied.

  A method for performing handover from the 3GPP communication area to the Non-3GPP communication area, which is currently being studied in 3GPP, will be described below. First, in a 3GPP communication area, a UE (User Equipment) which is a mobile communication terminal connects to a visited network (EPC: Evolved Packet Core) using a 3GPP radio access technology, and a gateway (for example, PGW: Packet Data Network Gateway). ) To an external network (PDN: Packet Data Network or Internet). The PGW is a gateway for transmitting (transmitting / receiving) user data related to the UE between the visited network and the external network, and establishes a PDN Connection used for communication with the UE. PDN Connection is composed of one or a plurality of communication bearers. A PDN Connection is established for each service provided to the UE. The service is related to an APN (Access Point Name) such as IMS (IP Multimedia Subsystem) or Internet connection.

  In establishing PDN Connection in this 3GPP communication area, an MME (Mobility Management Entity) transmits a PGW ID, which is PGW identification information, to an HSS (Home Subscriber Server) that manages subscriber information related to the UE. The PGW ID is identification information of a PGW that has established a PDN connection used for communication with the UE. The MME is a node device that performs PDN Connection settings, mobility management related to UE, communication control, and the like. The HSS is a server device that performs management for associating a PGW ID with each PDN Connection, management of subscriber information of the UE, and the like. The procedure for the MME to transmit the PGW ID to the HSS is described in Non-Patent Document 1 describing the ATTACH procedure.

  Next, when the UE moves to the Non-3GPP communication area, the UE connects to the IP access device using the Non-3GPP radio access technology. The IP access device makes an inquiry to the AAA (Authentication Authorization Accounting) server for the PGW ID of the PGW that has established PDN Connection with the UE so that the UE can continuously receive services from the external network. The AAA server executes communication authentication and the like in the Non-3GPP communication area. Here, the AAA server cooperates with the HSS, and can acquire the PGW ID managed in the HSS. The AAA server notifies the IP access device of the PGW ID acquired from the HSS.

  The IP access device can select a PGW that has established a PDN connection for the UE, using the PGW ID acquired from the AAA server. Further, the IP access device establishes a communication path or communication bearer between the UE and the PGW. In this way, the UE can continue to receive services from the external network via the same PGW even at the movement destination. That is, handover from the 3GPP communication area to the Non-3GPP communication area is realized by using the PGW as an anchor point.

  Next, a case where a failure occurs in the HSS holding the PGW ID will be described. When a failure occurs in the HSS, the service is temporarily stopped in the HSS, and the HSS is resumed by performing an initial setting operation. The procedure when this HSS is restarted is described in Non-Patent Document 2. Specifically, when the HSS resumes, it deletes all the PGW IDs it has held. Further, the HSS issues a Reset notification to the MME.

  When the MME receives a Reset notification from the HSS, the MME manages Location Information Confirmed in HSS (LICH) in the UE as Not Confirmed. Note that the state in which LICH is Not Confirmed indicates that the HSS has resumed and does not hold the PGW ID of the PGW that has established the PDN Connection used for communication with the UE.

  Here, in the 3GPP communication area, the UE transmits a TAU Request message to the MME in order to periodically perform TAU (Tracking Area Update) as providing location information. Upon receiving the TAU Request message, the MME transmits an ULR (Update Location Request) message to the HSS in order to update the TA (Tracking Area) of the UE. At this time, the MME transmits an ULR message in which an Active APN (Access Point Name) AVP (Attribute Value Pair) including the PGW ID of the PGW that has established the PDN Connection used for communication with the UE is set to the HSS. Although the case where the MME receives the TAU Request message has been described here, the MME establishes the PDN Connection used for communication with the UE even when the MME receives any message other than the TAU Request message from the UE. An ULR message in which an Active APN (Access Point Name) AVP (Attribute Value Pair) including the PGW ID of the PGW is set may be transmitted to the HSS.

  Therefore, the HSS can hold the PGW ID deleted by the resumption in association with the UE again by receiving the ULR message in which the Active APN AVP is set. Thereby, even after restarting, HSS can hold | maintain PGW ID linked | related with UE again. Therefore, when the UE is subsequently handed over to the Non-3GPP communication area, the AAA server can acquire the PGW ID of the PGW that has established the PDN Connection used for communication with the UE from the HSS. As a result, the UE can access the same PGW as the PGW in the 3GPP communication area even in the Non-3GPP communication area, and can perform handover using the PGW as an anchor point.

3GPP TS 23.401 V13.3.0 (2015-06) Section 5.3.2 3GPP TS 29.272 V13.2.0 (2015-06) Section 5.2.4 3GPP TS 23.402 V13.2.0 (2015-06) Sections 4.3.1.2, 4.3.4, Chapter 16

  The recovery procedure after resumption of HSS in Non-Patent Document 2 is based on the premise that the UE executes TAU in an area that does not involve MME change. Specifically, the UE transmits a TAU Request message to the MME that manages LICH as Not Confirmed. When the LICH of the UE that has transmitted the TAU Request message is Not Confirmed, the MME sends the ULR message in which the Active APN AVP including the PGW ID of the PGW that has established the PDN Connection used for communication with the UE is set to the HSS. Send to.

  Here, as a recovery procedure after resuming the HSS, a procedure when the UE moves to an area accompanied by an MME change will be described. First, when the HSS resumes, the HSS transmits a Reset notification to each MME. Thereby, each MME manages the LICH of the UE as Not Confirmed for the UE currently under the control of the own device. Next, when a certain UE moves to an area with an MME change, the UE transmits a TAU Request message to the newly changed MME. However, the MME after the change does not manage the LICH of the UE that has transmitted the TAU Request message as Not Confirmed. Therefore, the changed MME does not transmit the PGW ID of the PGW that has established the PDN Connection used for communication with the UE to the HSS. However, even in such a case, the MME after the change can acquire the information of the PGW ID from the MME before the change. Therefore, the MME after the change can be connected to the same PGW as the PGW to which the UE was connected before moving, using the acquired PGW ID.

  In such a situation, when the UE is further handed over from the 3GPP communication area to the Non-3GPP communication area, the HSS does not hold the PGW ID of the PGW that has established the PDN Connection used for communication with the UE. The AAA server cannot obtain the PGW ID from the HSS. For this reason, the IP access device in the Non-3GPP communication area cannot detect the PGW serving as an anchor point. As a result, there arises a problem that the UE cannot be handed over from the 3GPP communication area to the Non-3GPP communication area.

  An object of the present invention is to provide a mobile communication system, a mobility management apparatus, and a communication method that allow a UE to normally perform a handover from a 3GPP communication area to a non-3GPP communication area even after resumption of HSS in the above situation. And providing a program.

  A mobile communication system according to a first aspect of the present invention includes a PGW that establishes a PDN connection used for communication with a mobile communication terminal, an HSS that holds a PGW ID that is an identifier of the PGW, and the movement of the mobile communication terminal A mobility management device that performs management.When the mobility management device receives the Tracking Area Update message transmitted from the mobile communication terminal, the mobility management device sets the PGW ID regardless of the holding state of the PGW ID in the HSS. A set Update Location Request message is transmitted to the HSS.

  The mobility management device according to the second aspect of the present invention, when receiving the Tracking Area Update message transmitted from the mobile communication terminal, holds the PGW ID of the PGW that has established the PDN Connection used for communication with the mobile communication terminal Regardless of the holding state of the PGW ID in the HSS, a communication unit that transmits an Update Location Request message in which the PGW ID is set to the HSS is provided.

  The communication method according to the third aspect of the present invention, when receiving the Tracking Area Update message transmitted from the mobile communication terminal, holds the PGW ID of the PGW that has established the PDN Connection used for communication with the mobile communication terminal. The Update Location Request message in which the PGW ID is set is transmitted to the HSS regardless of the holding state of the PGW ID.

  When the program according to the fourth aspect of the present invention receives the Tracking Area Update message transmitted from the mobile communication terminal, the program in the HSS that holds the PGW ID of the PGW that has established the PDN Connection used for communication with the mobile communication terminal Regardless of the holding state of the PGW ID, the computer is caused to transmit an Update Location Request message in which the PGW ID is set to the HSS.

  According to the present invention, in the above situation, even after resumption of HSS, the UE can normally hand over from the 3GPP communication area to the Non-3GPP communication area, the mobile management device, the communication method, and A program can be provided.

1 is a configuration diagram of a mobile communication system according to a first embodiment. FIG. 3 is a configuration diagram of a mobile communication system according to a second embodiment. It is a block diagram of MME concerning Embodiment 2. FIG. It is a block diagram of UE concerning Embodiment 2. FIG. It is a figure which shows the flow of the TAU process concerning Embodiment 2. FIG. It is a figure which shows the flow of the TAU process concerning Embodiment 2. FIG. It is a figure which shows the Update Location Request message concerning Embodiment 2. FIG. FIG. 10 is a diagram showing a flow of a handover process according to the second embodiment. FIG. 3 is a configuration diagram of a mobile communication system according to a second embodiment. It is a figure which shows the setting content of the Context Response message concerning Embodiment 3. FIG. It is a figure which shows the setting content of Indication set to Indication Flags concerning Embodiment 3. FIG. It is a figure which shows the setting content of MME / SGSN UE EPS PDN Connections of the Context Response message concerning Embodiment 3. FIG. It is a figure which shows the content of ARD concerning Embodiment 4. FIG. FIG. 10 is a diagram showing a flow of handover processing according to the fifth embodiment. It is a figure which shows the flow of the authentication process performed among the AAA server concerning Embodiment 5, HSS, and MME.

(Embodiment 1)
Embodiments of the present invention will be described below with reference to the drawings. A configuration example of the mobile communication system according to the first exemplary embodiment of the present invention will be described using FIG. The mobile communication system of FIG. 1 includes a mobile communication terminal 10, a PGW 11, an HSS 12, and a mobility management device 100. The communication system of FIG. 1 is configured using node devices mainly defined in 3GPP.

  The mobile communication terminal 10 may be a mobile phone terminal, a smart phone terminal, a tablet terminal, or the like. Alternatively, the mobile communication terminal 10 may be an M2M (Machine to Machine) terminal, an MTC (Machine Type Communication) terminal, or the like. In addition, the mobile communication terminal 10 may be a computer device that operates when a processor executes a program stored in a memory. The mobile communication terminal 10 is assumed to be a terminal that can communicate in the 3GPP communication area and the Non-3GPP communication area.

  The PGW 11, the HSS 12, and the mobility management device 100 are node devices whose functions and operations are defined in 3GPP. The PGW 11, the HSS 12, and the mobility management device 100 may be computer devices that operate when a processor executes a program stored in a memory.

  The PGW 11 establishes a PDN connection used for communication with the mobile communication terminal 10. The PDN Connection is established between the mobile communication terminal 10 and the PGW 11 via an eNB (evolved Node B) (not shown) or an RNC (Radio Network Controller) (not shown). eNB and RNC are devices whose functions and operations are defined in 3GPP. The eNB is a base station that supports LTE (Long Term Evolution) as a wireless communication method. The RNC is a node device that supports a wireless communication system called 2G (second generation mobile phone) or 3G (third generation mobile phone). The PGW 11 is assigned a PGW ID that is an identifier uniquely identified in the communication system. The communication system may be, for example, an EPS (Evolved Packet System).

  The HSS 12 holds the PGW ID of the PGW that has established the PDN Connection used for communication with the mobile communication terminal 10. The mobility management device 100 performs mobility management related to the mobile communication terminal 10. The movement management may be, for example, managing position information that changes as the mobile communication terminal 10 moves. Further, the mobility management device 100 may be an MME or an SGSN (Serving GPRS Support Node).

  Here, the mobile communication terminal 10 periodically transmits a TAU Request message to the mobility management apparatus 100. Specifically, the mobile communication terminal 10 transmits a TAU Request message to the mobility management device 100 via the eNB.

  The Tracking Area is composed of one or more cells. The Tracking Area is information managed by the mobility management device 100, for example. In other words, the mobility management device 100 manages the Tracking Area as the location information of the mobile communication terminal 10. Further, when the mobile management device 100 calls the mobile communication terminal 10, the mobile management device 100 executes Paging for all mobile communication terminals located in the tracking area associated with the mobile communication terminal 10.

  When the mobility management device 100 receives the TAU Request message transmitted from the mobile communication terminal 10, the mobility management device 100 transmits a ULR message in which the PGW ID is set to the HSS 12 regardless of the holding state of the PGW ID in the HSS 12.

  The mobility management device 100 transmits a ULR message to the HSS 12 in order to update the location information of the mobile communication terminal 10 managed in the HSS 12. The HSS 12 normally acquires the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the mobile communication terminal 10 during the ATTACH process of the mobile communication terminal 10. Further, the HSS 12 holds the mobile communication terminal 10 and the PGW ID of the PGW 11 in association with each other. However, the HSS 12 deletes all held PGW IDs when it resumes due to the occurrence of a failure or the like. Therefore, the HSS 12 may not hold the PGW ID of the PGW 11 associated with the mobile communication terminal 10.

  The mobility management device 100 transmits a ULR message in which the PGW ID of the PGW 11 is set regardless of whether or not the HSS 12 holds the PGW ID of the PGW 11 associated with the mobile communication terminal 10. When receiving the ULR message, the HSS 12 already holds the PGW ID of the PGW 11, and if there is no change from the received PGW ID, the HSS 12 does not perform the process of updating the PGW ID of the PGW 11 associated with the mobile communication terminal 10. May be. On the other hand, if the already held PGW ID is different from the PGW ID set in the ULR message, it is overwritten and saved.

  When receiving the ULR message, the HSS 12 holds the PGW ID set in the ULR message in association with the mobile communication terminal 10 when the PGW ID of the PGW 11 is not held.

  Regardless of whether the HSS 12 holds the PGW ID of the PGW 11 or not, the mobility management device 100 manages the LICH as Not Confirmed for the mobile communication terminal 10 that has transmitted the TAU Request message. Regardless, it may be paraphrased. That is, the mobility management device 100 transmits the ULR message in which the PGW ID is set to the HSS 12 regardless of whether or not the LICH is managed as Not Confirmed for the mobile communication terminal 10 that has transmitted the TAU Request message.

  As described above, the mobility management apparatus 100 determines whether or not the HSS 12 holds the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the mobile communication terminal 10 that has transmitted the TAU Request message. Regardless, the ULR message in which the PGW ID is set is transmitted to the HSS 12. In other words, the mobility management device 100 transmits the ULR message in which the PGW ID is set to the HSS 12 regardless of whether or not the LICH is managed as Not Confirmed for the mobile communication terminal 10 that has transmitted the TAU Request message.

  As a result, the HSS 12 acquires the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the mobile communication terminal 10 even when the mobile communication terminal 10 moves with the change of the MME after restarting. be able to. Therefore, even when the MME that has transmitted the TAU Request message before the HSS 12 resumes and the MME that has transmitted the TAU Request message after the HSS 12 resumes, the mobile communication terminal 10 performs the handover process of the mobile communication terminal 10. Can be executed normally. Furthermore, even when the mobile communication terminal 10 moves from the 3GPP communication area to the Non-3GPP communication area, the handover process of the mobile communication terminal 10 can be executed normally.

  That is, the HSS 12 can update the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the mobile communication terminal 10 at the timing when the mobile communication terminal 10 transmits the TAU Request message. Therefore, even if the mobile communication terminal 10 moves with a change of the MME in the 3GPP communication area after the mobile device restarts, and the mobile communication terminal 10 moves to the Non-3GPP communication area, The PGW ID related to the mobile communication terminal 10 can be transmitted to the AAA server. Therefore, since the PGW ID of the PGW 11 serving as the anchor point can be specified also in the Non-3GPP communication area, the handover process related to the mobile communication terminal 10 can be executed normally.

(Embodiment 2)
Then, the structural example of the mobile communication system concerning Embodiment 2 of this invention is demonstrated using FIG. The mobile communication system of FIG. 2 has PGW11, HSS12, MME13, MME14, UE20, AAA server 31, IP access device 32, eNB40, eNB41, SGW50, SGW60, and PCRF70. Since the PGW 11 and the HSS 12 are the same as those in FIG. In FIG. 2, the MME 13 is used as the mobility management device 100.

  The UE 20 corresponds to the mobile communication terminal 10 in FIG. UE 20 is used as a general term for mobile communication terminals in 3GPP. The AAA server 31 is a device that performs authentication of the UE 20 in the Non-3GPP communication area. Further, the AAA server 31 is linked to the HSS 12 and receives the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 from the HSS 12.

  The IP access device 32 is a device that communicates with the UE 20 in the Non-3GPP communication area. The IP access device 32 may be, for example, an access point in a wireless LAN, or may be a device that performs mobile communication with the UE 20 using a communication method different from the communication method defined in 3GPP. The IP access device 32 may be a Trusted non-3GPP Access network, an ePDG (Evolved Packet Data Gateway), or a TWAN (Trusted WLAN Access Network) described in Non-Patent Document 3. The IP access device 32 may be a WT (Wireless LAN Termination).

  Further, the IP access device 32 acquires the PGW ID associated with the UE 20 from the AAA server 31. The IP access device 32 accesses the PGW 11 using the acquired PGW ID. As a result, the IP access device 32 can relay communication between the PGW 11 serving as an anchor point and the UE 20.

  eNB40 and eNB41 communicate with UE20 using LTE as a radio system. Moreover, SGW50 relays communication between eNB40 and PGW11, and SGW60 relays communication between eNB41 and PGW11. The PCRF 70 is a node device that manages a QoS policy or the like related to the UE 20.

  FIG. 2 shows that the UE 20 moves from the Tracking Area managed by the MME 13 to the Tracking Area managed by the MME 14 and further moves to the Non-3GPP communication area. The solid line in FIG. 2 indicates that control information or C-Plane information is transmitted or received. A broken line in FIG. 2 indicates that user data or U-Plane information is transmitted or received. Moreover, the arrow shown between UE20 of FIG. 2 shows that UE20 is moving.

  In the second embodiment, after the HSS 12 is resumed, the UE 20 moves from the Tracking Area managed by the MME 13 to the Tracking Area managed by the MME 14 and then moves to the Non-3GPP communication area. Mainly explained.

  Then, the structural example of MME13 concerning Embodiment 2 of this invention is demonstrated using FIG. Since the MME 14 has the same configuration as the MME 13, detailed description thereof is omitted. The MME 13 includes a communication unit (the communication unit may be referred to as a transmission and reception unit) 15 and a control unit 16. The communication unit 15 and the control unit 16 may be software or a module that operates when a processor executes a program stored in a memory. Alternatively, the communication unit 15 and the control unit 16 may be hardware such as a circuit or a chip.

  The communication unit 15 communicates with the eNB 40, the HSS 12, and the MME 14. Further, the communication unit 15 communicates with the UE 20 via the eNB 40. The control unit 16 generates a message to be transmitted to the eNB 40, the MME 14, and the HSS 12 via the communication unit 15, and further analyzes a message received from the eNB 40, the MME 14, and the HSS 12.

  For example, in the ATTACH process of the UE 20, the control unit 16 transmits a Notify Request message in which the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 is set to the HSS 12 via the communication unit 15. When the control unit 16 receives the TAU Request message transmitted from the UE 20 via the eNB 40, the control unit 16 transmits the ULR message in which the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 is set to the communication unit 15. To the HSS 12.

  Moreover, the control part 16 will manage LICH regarding UE20 as Not Confirmed, if Reset notification is received from HSS12.

  Then, the structural example of UE20 concerning Embodiment 2 of this invention is demonstrated using FIG. The UE 20 includes a 3GPP communication unit 21 and a Non-3GPP communication unit 22. The 3GPP communication unit 21 and the Non-3GPP communication unit 22 may be software or a module that operates when a processor executes a program stored in a memory. Alternatively, the 3GPP communication unit 21 and the Non-3GPP communication unit 22 may be hardware such as a circuit or a chip.

  The 3GPP communication unit 21 performs radio communication with the eNB 40. For example, the 3GPP communication unit 21 performs radio communication with the eNB 40 using LTE as a radio communication method. The 3GPP communication unit 21 transmits an ATTACH Request message to the eNB 40 when the UE 20 transitions from the power OFF state to the ON state. Further, the 3GPP communication unit 21 periodically transmits a TAU Request message for transmitting the location information of the UE 20 to the eNB 40. Alternatively, the 3GPP communication unit 21 transmits a TAU Request message to the eNB 40 when moving with a change of the MME.

  The Non-3GPP communication unit 22 performs wireless communication with the IP access device 32. For example, the Non-3GPP communication unit 22 may perform wireless LAN communication with the IP access device 32 or may communicate with the IP access device 32 using other communication methods.

  Subsequently, the flow of the TAU process and the handover process in the 3GPP communication area according to the second embodiment of the present invention will be described with reference to FIGS. 5 and 6. 5 and 6 refer to Figure 5.3.3.1-1 in 3GPP TS 23.401 V13.1.0 (2014-12). 5 and 6, it is assumed that the HSS 12 has restarted (S1) and the HSS 12 has transmitted a Reset notification to the MME 13 and the MME 14 (S2 and S3). First, the UE 20 determines to start the TAU process (S11). For example, the UE 20 starts the TAU process when it moves to a position that involves a change in MME or when it detects a periodic timing for starting the TAU process. In FIG. 5, the flow of the TAU process when the UE 20 moves to a position with an MME change will be described.

  Next, UE20 transmits a TAU Request message to MME14 via eNB41 (S12 and S13). The MME 14 is an MME (new MME) that manages the UE 20 after movement. Moreover, MME (old MME) which managed UE20 before movement is set to MME13.

  Next, the MME 14 transmits a Context Request message to the MME 13 that has managed the UE 20 before moving in order to request transmission of subscriber information and the like regarding the UE 20 (S14). Next, the MME 13 transmits a Context Response message in which subscriber information including the PGW ID related to the UE 20 is set to the MME 14 (S15). Next, the authentication process regarding UE20 is performed between UE20 and MME14, and also between MME14 and HSS12 (S16).

  Next, the MME 14 transmits a Context Acknowledge message to the MME 13 in order to instruct to change the gateway apparatus accommodating the UE 20 from the SGW (Serving Gateway) 50 to the SGW 60 as the UE 20 moves (S17). .

  Next, the MME 14 transmits a Create Session Request message to instruct the SGW 60 to generate a communication bearer with the PGW 11 (S18). Next, the SGW 60 transmits a Modify Bearer Request message to the PGW 11 in order to request generation of a communication bearer (S19). Next, the PGW 11 transmits a Modify Bearer Response message to the SGW 60 as a response to the Modify Bearer Request message (S20). Next, the SGW 60 transmits a Create Session Response message to the MME 14 as a response to the Create Session Request message in Step S18 (S21). In this way, the UE 20 establishes a PDN connection with the PGW 11 via the SGW 60.

  Next, the MME 14 transmits an Update Location Request message in which an Active APN AVP including the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 is set to the HSS 12 (S22). FIG. 7 shows an Update Location Request message in which the Active APN AVP is set. FIG. 7 refers to 3GPP TS 29.272 V13.2.0 (2015-06) Table 5.2.1.1.1 / 1. The MME 14 sets the Active APN AVP including the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 in the Update Location Request message regardless of whether or not the LICH related to the UE 20 is managed as Not Confirmed. To do. In other words, the MME 14 sets the Active APN AVP including the PGW ID in the Update Location Request message regardless of whether or not the PGW ID needs to be reset in the HSS 12 when the HSS 12 is restarted or reset. In addition, the MME 14 acquires information on the PGW ID from the MME 13 by using a Context Response message. Therefore, the MME 14 can use the acquired PGW ID to connect to the same PGW that the UE was connected to before moving, and can normally perform a handover even after the HSS is resumed.

  Next, a flow of handover processing from the 3GPP communication area to the non-3GPP communication area according to the second embodiment of the present invention will be described using FIG. FIG. 8 refers to FIG. 8.2.2-1 in Non-Patent Document 3. First, it is assumed that the UE 20 performs communication in the 3GPP communication area. At this time, it is assumed that a communication bearer is set between SGW 60 and PGW 11 using PMIPv6 or GTP tunnel (S31).

  Next, a case where the UE 20 moves from the 3GPP communication area to the Non-3GPP communication area will be described. At this time, the UE 20 detects the IP access device 32 (S32). When the UE 20 detects the IP access device 32, an authentication process is executed between the UE 20 and the IP access device 32 (S33). Moreover, the authentication regarding UE20 is performed also in a network (S34). In the authentication process of step S34, the AAA server 31 makes an inquiry to the HSS 12, acquires the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20, and transmits the PGW ID to the AAA proxy 71. The AAA proxy 71 is used as a proxy server for the AAA server 31.

  Further, in the authentication process of step S 34, the AAA proxy 71 transmits the PGW ID received from the AAA server 31 to the IP access device 32.

  Next, the UE 20 executes L3 Attach Trigger processing with the IP access device 32 (S35). Thereby, for example, the UE 20 transmits information on the APN used at the time of communication in the 3GPP communication area to the IP access device 32.

  Next, a Gateway Control Session Establishment Procedure is executed between the IP access device 32 and the vPCRF (Policy and Charging Rules Function) 72, and further between the vPCRF 72 and the hPCRF 73 (S36). The PCRF is a node device that manages a QoS policy or the like related to the UE 20. The vPCRF 72 executes policy control related to the UE 20 in the roaming destination network when the UE 20 roams. The hPCRF 73 executes policy control related to the UE 20 in the home network of the UE 20.

  In step S <b> 36, the hPCRF 73 transmits the QoS policy information regarding the UE 20 to the vPCRF 72. Further, the vPCRF 72 transmits (transfers) QoS policy information and the like related to the UE 20 to the IP access device 32.

  Next, the IP access device 32 transmits Proxy Binding Update to the PGW 11 using the PGW ID of the PGW 11 received in Step S34 (S37). By receiving the Proxy Binding Update, the PGW 11 associates the PDN Connection used for communication with the UE 20 in the 3GPP communication area and the communication bearer or communication connection in the Non-3GPP communication area, and executes the handover process of the UE 20.

  As described above, by using the mobile communication system according to the second embodiment of the present invention, the HSS 12 establishes a PDN connection used for communication with the UE 20 every time the UE 20 executes the TAU process. PGW ID can be obtained. In other words, the MME 14 sends the PGW ID of the PGW 11 that establishes the PDN Connection used for communication with the UE 20 to the HSS 12 every time the TAU process of the UE 20 is performed regardless of whether or not the LICH is managed as Not Confirmed. To do.

  As a result, even if the UE 20 moves with the change of the MME after the HSS 12 resumes, the HSS 12 establishes a PDN Connection used for communication with the UE 20 from the MME 14 that performs the mobility management related to the UE 20 after the movement. The PGW ID of the PGW 11 being received can be received (S22). As a result, the AAA server 31 can acquire the PGW ID related to the UE 20 from the HSS 12 even after the HSS 12 is restarted. Therefore, the UE 20 can access the same PGW before and after the movement. As an anchor point, a normal handover can be performed from the 3GPP communication area to the Non-3GPP communication area. As a result, the UE can continue to receive services from the external network via the same PGW even at the movement destination.

  In the second embodiment, the MME is mainly used as the mobility management apparatus 100. However, as shown in FIG. 9, SGSN 110 and SGSN 111 may be used instead of the MME. In this case, the MME 13 in FIG. 2 is replaced with the SGSN 110, and the MME 14 is replaced with the SGSN 111. Furthermore, eNB 40 and eNB 41 in FIG. 2 are replaced with RNC 130 and RNC 131. Further, the HSS 12 in FIG. 2 is replaced with the HLR 120. In that case, the UE 20 executes a RAU (Routing Area Update) process instead of the TAU process, and transmits a RAU Request to the SGSN 111 via the RNC 131.

(Embodiment 3)
Subsequently, a flow of the TAU process according to the third embodiment will be described. The flow of TAU processing in the third embodiment is the same as that in FIGS. 5 and 6 described in the second embodiment, and the message setting contents are different. Therefore, in the third embodiment, in FIG. 5 and FIG. 6, a message for setting contents different from the message in the second embodiment will be mainly described.

  In the third embodiment, it is assumed that the HSS 12 is restarted and a Reset notification is transmitted to the MME 13. Further, the MME 13 manages the LICH in the UE 20 as Not Confirmed by receiving the Reset notification.

  Further, the UE 20 moves from a position managed by the MME 13 to a position managed by the MME 14. In such a situation, the UE 20 executes the TAU process after step S11 in FIG.

  Steps S11 to S14 are the same as those in the second embodiment. In step S14, when the MME 13 specifies that the TAU process related to the UE 20 is being performed, in step S15, the MME 13 transmits to the MME 14 a Context Response message that sets that LICH is managed as Not Confirmed.

  Here, the setting contents of the Context Response message will be described with reference to FIG. FIG. 10 refers to 3GPP TS29.274 V13.2.0 (2015-06) Table 7.3.6-1. FIG. 10 shows that MME / SGSN UE EPS PDN Connections indicating that there is data set for each PDN Connection is set in the Context Response message. Further, it is indicated that the IE (Information Element) Type of MME / SGSN UE EPS PDN Connections is PDN Connection. Furthermore, it is shown that LICH is added to Indication Flags of the Context Response message. In addition, the IE Type of Indication Flags indicates Indication.

  Here, the setting contents of Indication set in Indication Flags of the Context Response message will be described with reference to FIG. FIG. 11 refers to 3GPP TS29.274 V13.2.0 (2015-06) Figure 8.12-1. FIG. 11 shows that a flag related to LICH is set in Bit 5 of Octet 9. For example, when 1 is set in Bit 5 of Octet 9, when the MME 14 transmits the Update Location Request message to the HSS 12, it indicates that the Active APN needs to be set in the Update Location Request message. . That is, when 1 is set in Bit 5 of Octet 9, it indicates that LICH is Not Confirmed.

  Here, the setting contents of the MME / SGSN UE EPS PDN Connections of the Context Response message will be described with reference to FIG. FIG. 12 refers to 3GPP TS29.274 V13.2.0 (2015-06) Table 7.3.6-2. FIG. 12 shows that a Context Identifier indicating PDN Connection identification information is added. The Context Identifier is information used to identify the PDN Connection, and is used when transmitting an Active-APN AVP described later. Therefore, the MME 13 sets a Context Identifier in the Context Response message together with a flag indicating that the LICH related to the UE 20 is Not Confirmed. Further, the MME 13 transmits a Context Response message including the PGW ID of the PGW 11 to the MME 14. Here, the information about the PGW ID is transferred from the MME 13 to the MME 14 using the MME / SGSN UE EPS PDN Connections IE, but the information about the PGW ID may be transferred using a dedicated IE.

  Returning to FIG. 5 and FIG. 6, steps S16 to S21 are the same as those in the second embodiment. In step S22, since the LICH related to the UE 20 is Not Confirmed, the MME 14 transmits, to the HSS 12, the ULR message in which the Active-APN AVP including the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 is set. To do. For example, in step S15, when the MME 14 receives a Context Response message in which Bit 5 of Octet 9 in the area indicating Indication is set to 1, the MME 14 sets the Context Identifier set in the Context Response message in step S15 to Active-APN AVP. Set to. Thereby, in step S22, MME14 transmits the ULR message which set Active-APN AVP containing PGW ID of PGW11 which has established PDN Connection used for communication with UE20 to HSS12.

  As described above, the MME 14 that has managed the UE 20 after moving can grasp the LICH management state related to the UE 20 by the Context Response message transmitted from the MME 13 that has managed the UE 20 before moving. it can. That is, even if the MME that manages the UE 20 changes from the MME 13 to the MME 14 due to the movement of the UE 20, the management state of the LICH can be taken over to the MME 14. Therefore, the HSS 12 can acquire the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 by receiving the ULR message from the MME 14.

  As a result, even if the UE 20 moves to the Non-3GPP communication area after moving with the change of the MME, the AAA server 31 has established a PDN connection used for communication with the UE 20 from the resumed HSS 12. The PGW ID of the PGW 11 can be acquired. Therefore, the UE 20 can normally hand over from the 3GPP communication area to the Non-3GPP communication area.

(Embodiment 4)
Next, the flow of the TAU process according to the fourth embodiment will be described. The flow of TAU processing in the fourth embodiment is the same as that in FIGS. 5 and 6 described in the second embodiment, and the contents set in the message are different. Therefore, in the fourth embodiment, in FIG. 5 and FIG. 6, a message for setting contents different from the message of the second embodiment will be mainly described.

  In the fourth embodiment, it is assumed that the HSS 12 is restarted and a Reset notification is transmitted to the MME 13. Further, the MME 13 manages the LICH in the UE 20 as Not Confirmed by receiving the Reset notification.

  Further, the UE 20 moves from a position managed by the MME 13 to a position managed by the MME 14. In such a situation, the UE 20 executes the TAU process after step S11 in FIG.

  Furthermore, 3GPP TS 29.272 V13.2.0 (2015-06) Table 7.7.31 / 1 stipulates that HSS12 retains Access-Restriction-Data (ARD) indicating an access network in which use of UE20 is restricted. Has been. As shown in FIG. 13, the ARD is defined by associating an area where the ARD is set and the restriction content. For example, when 1 is set in Bit 5 of the area indicating ARD, the UE 20 indicates that handover to the Non-3GPP communication area is not permitted. In addition, when 0 is set in each Bit in the area indicating ARD, it indicates that the use of the access network associated with each Bit is not restricted.

  Further, the HSS 12 transmits information regarding the ARD to the MME 13. For example, in periodic TAU processing of the UE 20, the HSS 12 sets ARD-related information in an Update Location Answer message that is a response message to the Update Location Request message, and transmits the information to the MME 13.

  Here, in step S14 of FIG. 5, when the MME 13 specifies that the TAU process related to the UE 20 is being performed, the MME 13 confirms whether 0 is set in Bit 5 of the area indicating the ARD of the UE 20. The fact that 0 is set in Bit 5 of the area indicating ARD indicates that the UE 20 is permitted to perform handover to the Non-3GPP communication area.

  When the MME 13 determines that the TAU process related to the UE 20 is being executed, the MME 13 transmits instruction information to the MME 14 when confirming that Bit 5 in the area indicating the ARD of the UE 20 is set to 0. Specifically, the MME 13 sets, in the Context Response message, information that instructs the HSS 12 to transmit the ULR message in which the Active-APN including the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 is set. The Context Response message is set and transmitted to the MME 14. Bit 5 of the area indicating ARD is a flag indicating a state of HTN3AA (Handover To Non 3GPP-Access Not Allowed). It should be noted that it may be defined other than ARD to mean this state, and the MME 13 may notify the MME 14 by setting this in a Context Response message.

  In step S15, when the MME 14 obtains information instructing to transmit the ULR message including the Active-APN AVP to the HSS 12, in step S22, the MME 14 transmits the ULR message in which the Active-APN including the PGW ID is set to the HSS 12. .

  Furthermore, when 0 is set in Bit 5 of the area indicating the ARD of the UE 20 and the LICH is managed as Not Confirmed, the MME 13 establishes the PDN connection used for communication with the UE 20 and the PGW of the PGW 11 Information instructing transmission of the ULR message in which the Active-APN including the ID is set to the HSS 12 may be set in the Context Response message. Then, the MME 13 may transmit the Context Response message to the MME 14.

  As described above, the MME 13 can transmit the instruction information regarding the content of the ULR message to the MME 14 that manages the UE 20 after movement, using the restriction content indicated in the ARD. That is, the MME 13 can instruct the MME 14 to set the PGW ID of the PGW 11 for which the UE 20 has set the communication bearer in the ULR message.

  Moreover, in Embodiment 4, MME14 sets Active-APN to a ULR message, only when UE20 is permitted to hand over to a Non-3GPP communication area. Thereby, when the processing in the fourth embodiment is executed, the information amount of the ULR message can be reduced as compared with the first and second embodiments in which the Active-APN is always set in the ULR message.

  In Embodiments 3 and 4, SGSN 110 and 111 may be used instead of MME 13 and 14, RNC 130 and RNC 131 may be used instead of eNB 40 and eNB 41, and HLR 120 is used instead of HSS 12. May be. In that case, the UE 20 executes the RAU process instead of the TAU process, and transmits the RAU Request to the SGSN 111 via the RNC 131.

(Embodiment 5)
Subsequently, the flow of the handover process from the 3GPP communication area to the non-3GPP communication area according to the fifth embodiment of the present invention will be described with reference to FIGS. 14 and 15. FIG. 14 refers to FIG. 8.2.2-1 in Non-Patent Document 3. First, it is assumed that the UE 20 performs communication in the 3GPP communication area. At this time, it is assumed that a communication bearer is set between SGW 60 and PGW 11 using PMIPv6 or GTP tunnel (S31).

  Next, a case where the UE 20 moves from the 3GPP communication area to the Non-3GPP communication area will be described. At this time, the UE 20 detects the IP access device 32 (S32). When the UE 20 detects the IP access device 32, an authentication process is executed between the UE 20 and the IP access device 32 (S33). Moreover, the authentication regarding UE20 is performed also in a network (S34). In the authentication process of step S34, the HSS 12 / AAA server 31 needs to transmit the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 to the AAA Proxy 71, but the HSS 12 is restarted so that the HSS 12 The PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 may be deleted from the HSS 12. In this case, the HSS 12 obtains the PGW ID of the PGW 11 that has established the PDN connection used for communication with the UE 20 by making an inquiry to the MME 14 that is the destination of the UE 20, and then transmits the PGW ID to the AAA Proxy 71. The AAA proxy 71 is used as a proxy server of the AAA server 31.

  Here, the AAA server 31, the HSS 12, and the PGW ID of the PGW 11 that has established the PDN Connection used by the HSS 12 for communication with the UE 20 due to the restart of the HSS 12 using FIG. 15 are deleted from the HSS 12. Details of the authentication process performed between the MMEs 14 will be described. When the restart operation occurs in the HSS 12 (S41), the HSS 12 sends a RESET message to the related MME (S42). The MME 14 that has received the RESET message lists all the subscribers accommodated in the HSS 12 to which the RESET message has been sent, sets it as a RESET ANSWER message, and transmits the RESET ANSWER message to the HSS 12 (S43). The list of subscribers set here may be configured by IMSI or another user identity. The HSS 12 can manage the association between the subscriber and the MME that the subscriber moves to after the RESET process by holding the subscriber list in MME units. This association enables an inquiry operation from the HSS 12 to the MME 14, which will be described below. However, the association may be used for other operations such as SMS reception, network-initiated subscriber location search, service provision from the MTC server, and the like. I do not care. Here, it is assumed that the UE 20 has moved from the 3GPP communication area to the Non-3GPP communication area (S44).

  As an authentication request for the UE 20, the HSS 12 receives an STa Access Authentication and Authorization Request message from the AAA server 31. (S45) In the STa Access Authentication and Authorization Request message, a parameter corresponding to IMSI is set as User Identity. When the HSS 12 does not hold the PGW ID for the User Identity, the HSS 12 further transmits a Status request message to the MME. (S46) This message includes subscriber information corresponding to IMSI and an information element indicating that information on the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 is requested. Further, the Status request message may be a RESET REQUEST message or another message. The MME 14 that has received the Status request message sets information on the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20, and transmits a Status answer message to the HSS 12. (S47). In addition, the Status answer message may be a RESET ANSWER message or another message. The HSS 12 transmits to the AAA server 31 a Trusted non-3GPP Access Authentication and Authorization Answer message in which information related to the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20 is set. (S48)

From here, it returns to FIG. 14 and continues and demonstrates after step S34.

  In the authentication process of step S34, the AAA proxy 71 transmits the PGW ID received from the HSS 12 / AAA server 31 to the IP access device 32.

  Next, the UE 20 executes L3 Attach Trigger processing with the IP access device 32 (S35). Thereby, for example, the UE 20 transmits information on the APN used at the time of communication in the 3GPP communication area to the IP access device 32.

  Next, a Gateway Control Session Establishment Procedure is executed between the IP access device 32 and the vPCRF (Policy and Charging Rules Function) 72, and further between the vPCRF 72 and the hPCRF 73 (S36). The PCRF is a node device that manages a QoS policy or the like related to the UE 20. The vPCRF 72 executes policy control related to the UE 20 in the roaming destination network when the UE 20 roams. The hPCRF 73 executes policy control related to the UE 20 in the home network of the UE 20.

  In step S <b> 36, the hPCRF 73 transmits the QoS policy information regarding the UE 20 to the vPCRF 72. Further, the vPCRF 72 transmits (transfers) QoS policy information and the like related to the UE 20 to the IP access device 32.

  Next, the IP access device 32 transmits Proxy Binding Update to the PGW 11 using the PGW ID of the PGW 11 received in Step S34 (S37). By receiving the Proxy Binding Update, the PGW 11 associates the PDN Connection used for communication with the UE 20 in the 3GPP communication area and the communication bearer or communication connection in the Non-3GPP communication area, and executes the handover process of the UE 20.

  As described above, by using the mobile communication system according to the second embodiment of the present invention, the HSS 12 makes an inquiry to the MME 14 that is the destination of the UE 20 using the authentication processing request from the AAA server 31 as a trigger. I can do things. As a result, the HSS 12 can acquire the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20.

  As a result, even if the UE 20 moves with the change of the MME after the HSS 12 resumes, the HSS 12 establishes a PDN Connection used for communication with the UE 20 from the MME 14 that performs the mobility management related to the UE 20 after the movement. The PGW ID of the PGW 11 being received can be received. As a result, the AAA server 31 can acquire the PGW ID related to the UE 20 from the HSS 12 even after the HSS 12 is restarted. Therefore, the UE 20 can access the same PGW before and after the movement. As an anchor point, a normal handover can be performed from the 3GPP communication area to the Non-3GPP communication area. As a result, the UE can continue to receive services from the external network via the same PGW even at the movement destination.

  Further, in the fifth embodiment, immediately after the HSS 12 is restarted and the MME receives the RESET signal, the UE 20 does not communicate with the MME and the UE 20 moves from the 3GPP communication area to the Non-3GPP communication area. The AAA server 31 can acquire the PGW ID of the PGW 11 that has established the PDN Connection used for communication with the UE 20, and has the same effect.

  In the second embodiment, the MME is mainly used as the mobility management apparatus 100. However, as shown in FIG. 9, SGSN 110 and SGSN 111 may be used instead of the MME. In this case, the MME 13 in FIG. 2 is replaced with the SGSN 110, and the MME 14 is replaced with the SGSN 111. Furthermore, eNB 40 and eNB 41 in FIG. 2 are replaced with RNC 130 and RNC 131. Further, the HSS 12 in FIG. 2 is replaced with the HLR 120. In that case, UE20 performs RAU (Routing Area Update) process instead of TAU process, and transmits RAU Request to SGSN111 via RNC.

  In the above-described embodiments, the present invention has been described as a hardware configuration, but the present invention is not limited to this. The present invention can also realize processing in each node device constituting the mobile communication system by causing a CPU (Central Processing Unit) to execute a computer program.

  In the above example, the program can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)) are included. The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

10 Mobile communication terminal 11 PGW
12 HSS
13 MME
14 MME
15 Communication unit 16 Control unit 20 UE
21 3GPP communication unit 22 Non-3GPP communication unit 31 AAA server 32 IP access device 40 eNB
41 eNB
50 SGW
60 SGW
70 PCRF
71 AAA Proxy
72 vPCRF
73 hPCRF
100 mobility management device 110 SGSN
111 SGSN
120 HLR
130 RNC
131 RNC

Claims (7)

A PGW for establishing a PDN Connection with a mobile communication terminal;
A subscriber information management device holding a PGW ID which is an identifier of the PGW;
A mobility management entity (MME) that performs mobility management of the mobile communication terminal that supports handover to non-3GPP on the network , and
The subscriber information management device is initialized ,
When the MME is changed, the changed MME sends a message in which the PGW ID is set to the subscriber information management device in Tracking Area Update (TAU) processing or Routing Area Update (RAU) processing . Mobile communication system. The mobile communication system according to claim 1,
  The changed MME receives a TAU Request message or a RAU Request message from the mobile communication terminal, and sets the PGW ID in the Tracking Area Update process or the Routing Area Update process based on the TAU Request message or the RAU Request message. A mobile communication system for transmitting a message to the subscriber information management device. A mobility management entity (MME) that performs mobility management of mobile communication terminals that support handover to non-3GPP on the network, and holds a PGW ID that is an identifier of a PGW that establishes a PDN connection with the mobile communication terminal when the subscriber information management device is initialized, the MME is changed,
MME provided with the transmission means which transmits the message which set the said PGW ID to the said subscriber information management apparatus in Tracking Area Update process or Routing Area Update process. The MME according to claim 3, wherein
  Further comprising receiving means for receiving a TAU Request message or a RAU Request message from the mobile communication terminal,
  The MME, wherein the transmission means transmits a message in which the PGW ID is set to the subscriber information management apparatus in a Tracking Area Update process or a Routing Area Update process based on the TAU Request message or the RAU Request message. A subscriber information management device that holds a PGW ID that is an identifier of a PGW that establishes a PDN connection with the mobile communication terminal is initialized, and performs mobility management of the mobile communication terminal that supports handover to non-3GPP on the network when Mobility management Entity (MME) is changed, Tracking Area in Update process or Routing Area Update process, a communication method for transmitting a message set for the PGW ID to the subscriber information management device. The communication method according to claim 5, wherein
  In the Tracking Area Update process or the Routing Area Update process, a TAU Request message or a RAU Request message is received from the mobile communication terminal,
  A communication method of transmitting a message in which the PGW ID is set to the subscriber information management apparatus in the Tracking Area Update process or the Routing Area Update process based on the TAU Request message or the RAU Request message. A subscriber information management device that holds a PGW ID that is an identifier of a PGW that establishes a PDN connection with the mobile communication terminal is initialized, and performs mobility management of the mobile communication terminal that supports handover to non-3GPP on the network when Mobility management Entity (MME) is changed, Tracking Area in Update process or Routing Area Update process program for executing a process of transmitting the message set for the PGW ID to the subscriber information management device to the computer.

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