Mobile communication network server device and call processing system

Abstract

To enable call processing for a wireless device even when the wireless device is connected to a mobile communication network other than the home mobile communication network. [Solution] The server device is equipped with a storage means for storing identification information for identifying a mobile communication network to which a wireless device, whose first mobile communication network to which the server device belongs is an HPLMN, is connected, and a notification means for, in response to receiving a message from a call processing system of the first mobile communication network requesting identification information of a connection base station to which the wireless device is connected, obtaining identification information of the connection base station from a management device that manages the wireless device's coverage area and notifying the call processing system if the wireless device is connected to the first mobile communication network, and notifying the call processing system of the specified identification information if the wireless device is connected to a mobile communication network other than the first mobile communication network.

Description

[Technical field]

[0001] The present disclosure relates to call processing techniques in mobile communication networks. [Background technology]

[0002] Mobile communication networks, also called public land mobile networks (PLMNs), provide voice call services. The voice call services are processed by, for example, the Internet Protocol (IP) Multimedia Subsystem (IMS), which is a call processing system disclosed in Non-Patent Document 1. First, a call processing sequence in a certain mobile communication network will be described with reference to FIG. 1.

[0003] Mobility management entities (MME)#1 and MME#2 in FIG. 1 are devices (functions) that manage the mobility of wireless devices (WDs), also called user equipment (UEs). In FIG. 1, MME#1 manages the mobility of WD#1, and MME#2 manages the mobility of WD#2. Also, IMS#1 and IMS#2 in FIG. 1 are collective names for a plurality of devices (functions) that constitute IMS, such as a serving call session control function (S-CSCF) and a proxy CSCF (P-CSCF) defined by 3GPP (registered trademark). In FIG. 1, IMS#1 controls outgoing calls (calls) by WD#1 and incoming calls (calls received) to WD#1, and IMS#2 controls outgoing calls by WD#2 and incoming calls to WD#2. Note that IMS#1 and IMS#2 may be the same. Also, MME#1 and MME#2 may be the same.

[0004] Furthermore, the home subscriber server (HSS) in FIG. 1 is a server device that manages subscriber information of users of the WD. The MME is configured to acquire the tracking area (TA) (location information) of the WD when the WD registers the WD to the mobile communication network, and notify the HSS of the acquired location information. The WD is also configured to execute a TA update (TAU) process to notify the MME of the TA at that time when a predetermined condition is satisfied in an idle state. The MME is configured to notify the HSS of the location information of the WD when the WD, which is a mobility management target, executes TAU. Therefore, the HSS holds information that identifies the MME that manages the location information of the WD. The information that identifies the MME can be, for example, a FQDN (fully qualified domain name). Therefore, the HSS stores information indicating that the device that manages the mobility of the WD#1 is the MME#1 and the device that manages the mobility of the WD#2 is the MME#2.

[0005] In S1, WD#1 requests IMS#1 to make a call to WD#2. In S2, IMS#1 inquires of HSS about the base station (BS) to which WD#1 is connected. In S3, HSS communicates with MME#1 that manages the mobility of WD#1 to obtain BS information of the BS to which WD#1 is connected. Since WD#1 is in an active state in S1, MME#1 can identify the BS to which WD#1 is currently connected. The BS information can be a BS identifier that uniquely identifies the BS, for example, an E-UTRAN cell group identifier (ECGI). In S4, HSS notifies IMS#1 of the BS information of the BS to which WD#1 is connected.

[0006] IMS#1 holds the determination information shown in Fig. 2. The determination information is information indicating the correspondence between the BS information of all BSs in the mobile communication network and the billing identifier indicating the billing area to which the BS belongs. IMS#1 records the billing identifier indicating the billing area of ​​the BS to which WD#1 is connected in the record of the call from WD#1 to WD#2 for use in later billing processing. For example, if the BS information of BS#1 is ECGI#1 in Fig. 2, C#1 is recorded as the billing identifier in the record of the call from WD#1 to WD#2.

[0007] After acquiring the BS information of the BS to which WD#1 is connected and associating it with the billing identifier, IMS#1 acquires information of the IMS controlling the call processing of the called party WD#2 from the HSS in S5. In this example, IMS#1 acquires information indicating IMS#2 in S5. IMS#1 notifies IMS#2 of the call from WD#1 to WD#2 in S6. IMS#2 inquires of the HSS about the BS to which WD#2 is connected in S7. HSS communicates with MME#2 that manages the mobility of WD#2 in S8 to acquire the BS information of the BS to which WD#2 is connected. When WD#2 is in the idle state, MME#2 transitions WD#2 to the active state by executing a paging process, and thus can identify the BS to which WD#2 is connected. HSS notifies IMS#2 of the BS information of the BS to which WD#2 is connected in S9.

[0008] IMS#2 also holds the determination information shown in Fig. 2. IMS#2 records the billing identifier corresponding to the BS to which WD#2 is connected in the record of the call made by WD#1 to WD#2 for use in later billing processing. For example, if the BS information of BS#2 is ECGI#2 in Fig. 2, C#2 is recorded as the billing identifier in the record of the call made by WD#1 to WD#2. After acquiring the BS information of the BS to which WD#2 is connected and associating it with the billing identifier, IMS#2 notifies WD#2 of the incoming call from WD#1 in S10. [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] 3GPP(registered trademark) TS.23.228, V18.4.0, December 2023 Summary of the Invention [Problem to be solved by the invention]

[0010] Currently, when a fault occurs in a mobile communication network, a WD that has the mobile communication network as its home PLMN (HPLMN) is rescued by another mobile communication network (another PLMN). In the following description, it is assumed that the HPLMNs of WD#1 and WD#2 in Fig. 1 are the first mobile communication network, and that the HSS, IMS#1, and IMS#2 in Fig. 1 are devices or systems (or functions) of the first mobile communication network.

[0011] For example, assume that WD#1 is connected to a second mobile communication network different from the first mobile communication network due to a failure of the first mobile communication network. In this case, WD#1 is connected to a BS of the second mobile communication network, and MME#1 managing the mobility of WD#1 is a device of the second mobile communication network. Even if MME#1 is a device of the second mobile communication network, MME#1 can determine that the HPLMN of WD#1 is the first mobile communication network based on the IMSI (International Mobile Subscriber Identity) of WD#1, so MME#1 reports the location information of WD#1 to the HSS of the first mobile communication network, not to the HSS of the second mobile communication network. Therefore, even if WD#1 is connected to the second mobile communication network, the HSS of the first mobile communication network shown in FIG. 1 can obtain information identifying the MME managing the mobility of WD#1.

[0012] Therefore, when WD#1 connected to the second mobile communication network calls WD#2 connected to the first mobile communication network, the HSS acquires BS information from MME#1 of the second mobile communication network in S3 and transmits the BS information to IMS#1 in S4. However, since this BS information is an identifier (e.g., ECGI) of the BS of the second mobile communication network, there is no entry for this BS information in the determination information shown in FIG. 2. Therefore, IMS#1 cannot acquire the billing identifier of the BS to which WD#1 is connected, and a processing error occurs, and the call processing is stopped. Note that a processing error also occurs in S9 when the calling WD#1 is connected to the first mobile communication network, but the called WD#2 is connected to the second mobile communication network.

[0013] One method for avoiding the processing error is to add, to the determination information, the BS information of the BSs used by all other mobile communication networks that rescue the WD in which the first mobile communication network is the HPLMN when the first mobile communication network fails. However, the number of BSs used by each mobile communication network is huge, and considering the addition and removal of BSs, it is not realistic to manage the BS information of the BSs used by other mobile communication networks.

[0014] The present disclosure provides a technique that enables call processing for a wireless device even when the wireless device is connected to a mobile communication network other than its home mobile communication network. [Means for solving the problem]

[0015] According to one aspect of the present disclosure, a server device includes: a storage means for storing identification information for identifying a mobile communication network to which a wireless device, which has a first mobile communication network to which the server device belongs as a home public land mobile network (HPLMN), is connected; and a notification means for, in response to receiving a message requesting identification information of a connection base station to which the wireless device is connected from a call processing system of the first mobile communication network, acquiring identification information of the connection base station from a management device that manages a coverage area of ​​the wireless device and notifying the call processing system of the identification information when the wireless device is connected to the first mobile communication network, and notifying the call processing system of predetermined identification information when the wireless device is connected to a mobile communication network other than the first mobile communication network. The predetermined identification information is different from the identification information of all base stations of the first mobile communication network. . Effect of the Invention

[0016] According to the present disclosure, it is possible to process calls to a wireless device even when the wireless device is connected to a mobile communication network other than its home mobile communication network. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a diagram showing an example of a call processing sequence. [Diagram 2] FIG. 11 is a diagram showing an example of determination information. [Diagram 3] 2 is a sequence diagram of a call process according to one embodiment. [Figure 4] FIG. 13 illustrates an example of determination information according to one embodiment. [Diagram 5] FIG. 11 is a diagram showing an example of determination information according to another embodiment. [Figure 6] FIG. 1 is a functional block diagram showing an example of the configuration of an HSS. [Figure 7] FIG. 1 is a functional block diagram showing an example of the IMS configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features among the multiple features described in the embodiments may be arbitrarily combined. In addition, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0019] First Embodiment In the following, the HPLMN of WD#1 and WD#2 in Figure 1 is the first mobile communications network, the HSS, IMSI#1 and IMSI#2 in Figure 1 are devices or systems (or functions) of the first mobile communications network, and the sequence when WD#1 or WD#2 is connected to the second mobile communications network due to a failure in the first mobile communications network is described, focusing on the differences from Figure 1.

[0020] FIG. 3(A) is a sequence diagram when WD#1 is connected to the second mobile communication network. In S1, WD#1 requests IMS#1 to call WD#2. In S2, IMS#1 inquires of HSS about the base station (BS) to which WD#1 is connected. In S20, HSS determines whether WD#1 is currently connected to the first mobile communication network or another mobile communication network based on the identification information of MME#1 that manages the mobility of WD#1. The identification information of MME is, for example, FQDN. Since FQDN includes information for identifying the mobile communication network to which MME belongs, HSS can determine whether MME#1 is a device of the first mobile communication network or another mobile communication network based on FQDN. In this example, WD#1 is connected to the second mobile communication network, so HSS determines in S20 that WD#1 is connected to the second mobile communication network. When the HSS determines that the WD#1 is connected to a mobile communication network different from the first mobile communication network, it transmits dummy BS information to the IMS#1 in S21 without inquiring of the MME#1 about the BS to which the WD#1 is connected. The dummy BS information is information different from the BS information of all BSs used in the first mobile communication network, and is stored in the HSS in advance.

[0021] In this embodiment, the determination information stored in IMS#1 is provided with an entry for dummy BS information shown as "ECGI#X" in Fig. 4. IMS#1, to which the dummy BS information has been notified in S21, records a billing identifier C#X in the record of the call made by WD#1 to WD#2 based on the determination information in Fig. 4. The subsequent processing is the same as the processing from S5 in Fig. 1.

[0022] FIG. 3B is a sequence diagram when WD#2 is connected to the second mobile communication network. As in FIG. 1, in S6, IMS#2 receives a notification of an outgoing call from WD#1 to WD#2 from IMS#1. In S7, IMS#2 inquires of HSS about the BS to which WD#2 is connected. In S30, HSS judges whether WD#2 is currently connected to the first mobile communication network or another mobile communication network based on specific information of MME#2 that manages the mobility of WD#2. In this example, since WD#2 is connected to the second mobile communication network, HSS judges that WD#2 is connected to the second mobile communication network in S30. When HSS judges that WD#2 is connected to a mobile communication network different from the first mobile communication network, it transmits dummy BS information to IMS#2 in S31 without inquiring of MME#2 about the BS to which WD#2 is connected. IMS#2, which has been notified of the dummy BS information in S31, records the billing identifier C#X in the record of the call from WD#1 to WD#2 based on the determination information in Fig. 4. After that, IMS#2 notifies WD#2 of the incoming call from WD#1 in S10.

[0023] As described above, in this embodiment, before inquiring of the MME that manages the mobility of the WD about the BS to which the WD is connected, the HSS judges whether the WD is connected to the same mobile communication network as the HSS. If the WD is connected to a mobile communication network different from the HSS, the HSS notifies the IMS of dummy BS information. In addition, a dummy billing identifier (C#X in FIG. 4) corresponding to the dummy BS information is stored in the judgment information of the IMS. With this configuration, even if the WD on the calling or called side is connected to another mobile communication network, a processing error can be avoided and call processing for the WD can be performed. In this case, the billing identifier of the WD connected to the other mobile communication network is a dummy, but when the WD connected to the other mobile communication network is the calling or called side, it is sufficient to obtain information on communication via the other mobile communication network, and this does not pose a problem.

[0024] In this embodiment, when the WD is connected to a mobile communication network different from the first mobile communication network, the same dummy BS information is used regardless of the connected mobile communication network. For example, even when the WD is connected to the second mobile communication network, the dummy BS information is ECGI#X. However, it is also possible to use different dummy BS information depending on the mobile communication network to which the WD is connected, such as using ECGI#X as the dummy BS information when the WD is connected to the second mobile communication network and using ECGI#Y as the dummy BS information when the WD is connected to the third mobile communication network.

[0025] In the embodiment, the management device that manages the mobility of the WD, that is, the location area, is assumed to be MME according to the terminology of the 4th generation long-term evolution (LTE) of 3GPP (registered trademark). However, the management device that manages the location area of ​​the WD is not limited to MME, and may be any device that manages the location area of ​​the WD, such as a device that implements the access and mobility management function (AMF) specified in the 5th generation New Radio (NR). In addition, the server device that can access information that identifies the management device that manages the mobility of the WD is assumed to be HSS according to the terminology of LTE, but the server device that can access information that identifies the management device that manages the mobility of the WD may be any server device that has information that identifies the management device that manages the mobility of the WD, such as the 5th generation unified data management (UDM).

[0026] Second Embodiment Next, the second embodiment will be described with a focus on the differences from the first embodiment. In the first embodiment, the HSS determines the PLMN to which the WD is connected, and if the WD is connected to a PLMN different from the HPLMN, the HSS notifies the IMS of dummy BS information. In this embodiment, regardless of which mobile communication network the WD is connected to, the HSS inquires the MME that manages the mobility of the WD about the BS to which the WD is connected, obtains BS information, and notifies the IMS of the obtained BS information. Therefore, the sequence of calling and receiving is the same as that in FIG. 1. However, in this embodiment, a regular expression is used in the determination information to avoid processing errors.

[0027] FIG. 5 shows an example of the determination information according to the present embodiment. ECGI, which is an example of BS information, is information in which network information indicating a PLMN (mobile communication network) and other information are linked. For example, if the network information indicating a first mobile communication network that is a PLMN is "MMMMM", the BS information of the BS in the first mobile communication network will be "MMMMM00000001" or "MMMMM00000002" as shown in FIG. 5. Note that the 8-digit number following "MMMMM" is other information and is used for the purpose of uniquely identifying each BS in the first mobile communication network. Note that the length / format of the network information and the length / format of the other information are examples and are not limited to the above lengths / formats.

[0028] For example, if the network information indicating the second mobile communication network is "XXXXX" and the network information indicating the third mobile communication network is "YYYYY", the determination information has entries of "XXXXX*" and "YYYYY*" as shown in Fig. 5. Here, the asterisk "*" indicates that any information matches. In other words, "XXXXX*" in Fig. 5 indicates that if the first five are "X", they will match regardless of the values ​​thereafter.

[0029] When WD#1 connects to a BS of a second mobile communication network and the BS information of the BS is "XXXXX00000001", IMS#1 acquires the BS information "XXXXX00000001" in S4 of Fig. 1. Since "XXXXX00000001" matches the entry for "XXXXX*" in the determination information, IMS#1 records C#X as a billing identifier in the record of the call made by WD#1 to WD#2.

[0030] Furthermore, when WD#2 connects to a BS of a third mobile communication network and the BS information of the BS is "YYYYY00000100", IMS#2 acquires the BS information "YYYYY00000100" in S9 of Fig. 1. Since "YYYYY00000100" matches the entry for "YYYYY*" in the determination information, IMS#2 records C#Y as a billing identifier in the record of the call made by WD#1 to WD#2.

[0031] As described above, in this embodiment, regular expressions are used in the BS information used to determine the billing identifier in the IMS. Specifically, for a BS in another mobile communication network, only the network information in the BS information is used to determine the billing identifier. For a BS in the same mobile communication network, the IMS determines the billing identifier using the network information and other information in the BS information. With this configuration, even if the calling or called WD is connected to another mobile communication network, it is possible to avoid processing errors and perform call processing for the WD.

[0032] <Device configuration> Fig. 6 is a functional block diagram showing a configuration example of HSS1 according to the first embodiment. HSS1 belongs to the first PLMN, that is, it is assumed to be used in the first PLMN. HSS1 may be composed of one device, or may be composed of multiple devices capable of communicating with each other. Fig. 6 shows only parts necessary for explaining the embodiment, and parts not necessary for understanding the embodiment are omitted.

[0033] The storage unit 11 stores specific information for identifying a PLMN to which a WD with a first PLMN as an HPLMN is connected. The HSS1 receives the mobility of the WD, that is, the location information of the WD from a management device that manages the location area of ​​the WD, for example, an MME. Therefore, the HSS1 can obtain information for identifying a management device that manages the location area of ​​the WD, for example, an FQDN. Since the FQDN includes specific information for identifying a PLMN to which the management device belongs, the HSS1 can obtain and store in the storage unit 11 the specific information for identifying a PLMN to which the WD is connected.

[0034] In response to receiving a message from a call processing system of the first PLMN, requesting BS information (identification information) of a base station to which a first wireless device, which uses the first PLMN as an HPLMN, is connected, the determination unit 12 determines whether the first wireless device is connected to the first PLMN based on the identification information. The call processing system is, for example, an IMS.

[0035] When the first wireless device is connected to the first PLMN, the notification unit 13 acquires identification information of the connected base station from a first management device that manages the area where the first wireless device is located, and notifies the call processing system of the identification information. On the other hand, when the first wireless device is connected to a PLMN other than the first PLMN, the notification unit 13 notifies the call processing system of predetermined identification information. Note that in this case, the notification unit 13 may omit the process of communicating with the first management device to acquire the identification information of the connected base station.

[0036] The predetermined identification information is different from the identification information of all base stations in the first PLMN, and is stored in advance in the storage unit 11. Note that the predetermined identification information can be different depending on the mobile communication network to which the first wireless device is connected.

[0037] Fig. 7 is a functional block diagram showing a configuration example of an IMS2 according to the second embodiment. The IMS2 is an example of a call processing system and may include one or more devices. Note that Fig. 7 shows only parts necessary for explaining the embodiment, and parts not necessary for understanding the embodiment are omitted. Note that the IMS2 belongs to the first PLMN.

[0038] The storage unit 21 stores the determination information indicating the correspondence between the identification information of the base station and the charging area. The identification information of the base station includes network information indicating the PLMN to which the base station belongs and other information. The other information may be information for uniquely identifying the base station within the PLMN.

[0039] When performing call processing for a first wireless device having the first PLMN as an HPLMN, the acquisition unit 22 performs an acquisition process to acquire first identification information of a connecting base station to which the first wireless device is connected. For example, the acquisition unit 22 may acquire the first identification information from an HSS of the first PLMN.

[0040] The determination unit 23 determines and records a charging area (charging identifier) ​​corresponding to the first identification information based on the determination information. Here, for base stations of PLMNs different from the first PLMN, the determination information indicates a correspondence relationship between network information and charging areas. Then, when the connected base station is a base station of PLMNs different from the first PLMN, the determination unit 23 determines a charging area corresponding to the first identification information using network information included in the first identification information. On the other hand, when the connected base station is a base station of the first PLMN, the determination unit 23 determines a charging area corresponding to the first identification information using network information and other information included in the first identification information. For example, the determination unit 23 may determine a charging area based on determination information that completely matches the first identification information among the identification information included in the determination information. Note that, when the same charging area corresponds to multiple BSs and regular expressions can be used for the BS information of the multiple BSs, the determination unit 23 may determine a charging area using network information in the first identification information and part of information in the other information. For example, if the BS information "MMMMM00000001" to MMMMM00000099" correspond to the same charging area, the determination information can use an entry of "MMMMM000000*", and the determination unit 23 can determine the charging area using the upper six digits rather than all eight digits of the other information.

[0041] Furthermore, according to the present disclosure, there is provided a computer program, which when executed on one or more devices having one or more processors, causes the one or more devices to operate as the above-mentioned HSS1 or IMS2, and a non-transitory computer-readable storage medium having stored the computer program. Furthermore, according to the present disclosure, there is provided a method executed by the HSS1 or IMS2, a computer program that causes one or more devices having one or more processors to execute the method, and a non-transitory computer-readable storage medium having stored the computer program.

[0042] With the above configuration, it is possible to process calls to a wireless device even when the wireless device is connected to a mobile communication network other than the home mobile communication network. This makes it possible to contribute to Goal 9 of the United Nations' Sustainable Development Goals (SDGs), which is to "build resilient infrastructure, promote sustainable industrialization and foster innovation."

[0043] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0044] 11: storage unit, 12: judgment unit, 13: notification unit

Claims

1. A server device, a storage means for storing identification information for identifying a mobile communication network to which a wireless device, which has a first mobile communication network to which the server device belongs as a home public land mobile network (HPLMN), is connected; a notification means for, in response to receiving a message requesting identification information of a connection base station to which the wireless device is connected from a call processing system of the first mobile communication network, acquiring identification information of the connection base station from a management device that manages an area in which the wireless device is located and notifying the call processing system when the wireless device is connected to the first mobile communication network, and notifying the call processing system of predetermined identification information when the wireless device is connected to a mobile communication network other than the first mobile communication network; Equipped with A server device, wherein the predetermined identification information is different from identification information of all base stations of the first mobile communication network.

2. 2. The server device according to claim 1, wherein when the wireless device is connected to the other mobile communication network, the notification means notifies the call processing system of the specified identification information without obtaining identification information of the connected base station from the management device.

3. The server apparatus according to claim 1 , wherein the predetermined identification information differs depending on a mobile communication network to which the wireless device is connected.

4. The server device according to claim 1 , wherein the identification information is information for identifying the management device that manages an area where the wireless device is located.

5. The server device according to claim 4 , wherein the information for identifying the management device includes information indicating a mobile communication network to which the management device belongs.

6. The server device according to claim 4 , wherein the management device is a Mobility Management Entity (MME) or a device implementing an Access and Mobility Management Function (AMF).

7. The server device of claim 1 , wherein the call processing system is an Internet Protocol (IP) Multimedia Subsystem (IMS).

8. The server device of claim 1 , wherein the server device is a Home Subscriber Server (HSS) or a device implementing Unified Data Management (UDM).

9. A computer program product which, when executed on one or more processors of an apparatus having one or more processors, causes the apparatus to function as a server apparatus according to any one of claims 1 to 8.

10. A call processing system, comprising: A storage means for storing determination information indicating a correspondence relationship between identification information of a base station and a charging area, the identification information of the base station including network information indicating a mobile communication network to which the base station belongs and other information; an acquisition means for acquiring identification information of a base station to which a wireless device is connected when performing call processing for the wireless device having a first mobile communication network as a home public land mobile network (HPLMN); a determination means for determining the charging area corresponding to the identification information of the connected base station based on the determination information; Equipped with The determination information indicates, for a base station of a mobile communication network different from the first mobile communication network, a correspondence relationship between the network information and the charging area, The determination means, when the connecting base station is a base station of a mobile communication network different from the first mobile communication network, determines the charging area corresponding to the identification information of the connecting base station using the network information included in the identification information of the connecting base station, and when the connecting base station is a base station of the first mobile communication network, determines the charging area corresponding to the identification information of the connecting base station using the network information and the other information included in the identification information of the connecting base station.

11. The call processing system of claim 10, wherein the call processing system is an Internet Protocol (IP) Multimedia Subsystem (IMS).

12. 12. The call processing system of claim 10 or 11, wherein the call processing system includes one or more devices.

13. A computer program product which, when executed on one or more processors of said one or more devices, causes said one or more devices to function as the call processing system of claim 12.

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