Mobile communication network

Abstract

To provide a technique capable of suppressing an influence due to a failure of a NF.SOLUTION: A mobile communication network comprises: determination means of determining whether or not a component in associated with identification information is generated in a calculation machine group of a mobile communication network on the basis of the identification information contained in a resistor request message when receiving a register request message for requesting a registration to the mobile communication network from a radio device; and processing means of performing a processing for generating the component in associated with the identification information to the calculation machine group of the mobile communication network in the case where it is determined that the component in associated with the identification information is not generated in the calculation machine group of the mobile communication network. The component in associated with the identification information includes one or more dedicated NF in one or more radio devices using the identification information.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a mobile communication network using virtualization technology.

Background Art

[0002] Non-Patent Document 1 discloses a fifth-generation (5G) mobile communication network. For example, a 5G mobile communication network has a core network (CN) and a radio access network (RAN). The core network (CN) includes various network functions (NFs). An example of an NF is an access and mobility function (AMF) that manages mobility, a session management function (SMF) that manages sessions, and a user plane function (UPF) that relays data transmitted and received by a user. Each NF of the CN is arranged, for example, at one or more central sites.

[0003] The central site can be connected to one or more edge sites. At the edge site, a distributed unit (DU) and a central unit (CU), which are components of the RAN, are arranged. The edge site is connected to one or more antenna sites. At the antenna site, a radio unit (RU), which is a component of the RAN, is arranged. Note that the edge site may include the antenna site. That is, one of the one or more antenna sites connected to the edge site may be the same site as the edge site.

[0004] The 5G mobile communication network aims to separate the control plane (CP) and the user plane (UP). For example, the AMF and the SMF are functions of the CP, and the UPF is a function of the UP. Accordingly, the CU is also separated into a function of the CP (CU-CP) and a function of the UP (CU-UP). Similarly, the DU is also separated into a function of the CP (DU-CP) and a function of the UP (DU-UP).

[0005] When a wireless device (WD), such as a user equipment (UE) or IoT device, sends an IP packet to a server on the internet, for example, it is sent to the RU, DU-UP, and CU-UP. At the CU-UP, the packet is encapsulated in a GTP packet. The GTP packet is forwarded according to the PDU session and reaches the UPF at the point of connection to the internet. The UPF at the point of connection to the internet sends the IP packet contained in the GTP packet to the internet. The SMF performs tasks such as establishing the PDU session.

[0006] Each NF, CU, and DU, excluding RUs that transmit and receive wireless signals, can be configured using virtualization technology. In other words, multiple general-purpose computers (hereinafter referred to as computer clusters) can be placed at central and edge sites, and each NF, CU, and DU can be implemented in software within the computer clusters. This makes it possible to increase or decrease the computing resources allocated to individual NFs, CUs, and DUs depending on the state of the mobile communication system, and to increase or decrease the number of CUs, DUs, and NFs depending on the services provided. Although CUs and DUs are not named NFs, in the following explanation, CUs and DUs that can be implemented using virtualization technology will be considered one type of NF. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] "5G System Overview", [online], August 8, 2022, [Retrieved January 20, 2023], Internet,<URL:https: / / www.3gpp.org / technologies / 5g-system-overview> [Overview of the project] [Problems that the invention aims to solve]

[0008] Each NF in a mobile communication network is shared by multiple WDs, and therefore, a failure in an NF affects many WDs.

[0009] This disclosure provides a technology to mitigate the effects of NF failures. [Means for solving the problem]

[0010] According to one aspect of the present disclosure, a mobile communication network, upon receiving a registration request message from a wireless device requesting registration to the mobile communication network, includes a determination means for determining, based on the identification information contained in the registration request message, whether a component associated with the identification information has been generated in the computer group of the mobile communication network; and a processing means for generating the component associated with the identification information in the computer group of the mobile communication network if the determination means determines that the component associated with the identification information has not been generated in the computer group of the mobile communication network, wherein the component associated with the identification information has one or more network functions dedicated to one or more wireless devices using the identification information. The one or more network functions include one or more distributed units (DUs) and central units (CUs). . [Effects of the Invention]

[0011] According to this disclosure, the impact of NF failures can be mitigated. [Brief explanation of the drawing]

[0012] [Figure 1] A diagram illustrating the configuration of a mobile communication system according to one embodiment. [Figure 2] A sequence diagram of the registration process when a component has not been generated, according to one embodiment. [Figure 3] A sequence diagram of the registration process when a component has been generated, according to one embodiment. [Figure 4] A sequence diagram of the component deletion process according to one embodiment. [Figure 5]A sequence diagram of the PDU session establishment process according to one embodiment. [Figure 6] A diagram illustrating the configuration of a mobile communication network according to one embodiment. [Modes for carrying out the invention]

[0013] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features from the multiple features described in the embodiments may be combined arbitrarily. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.

[0014] Figure 1 is a configuration diagram of a mobile communication system including a WD1 and a mobile communication network according to this embodiment. The central site 4 accommodates one or more edge sites 3, and one edge site 3 accommodates one or more antenna sites. RU2 is located at the antenna sites and transmits and receives radio signals with the WD1. The edge sites 3 are located at the controller 31, the computer group 32, and the transfer unit 33. In Figure 1, for the sake of understanding this embodiment, the controller 31 and the transfer unit 33 are shown as separate from the computer group 32, but the controller 31 and the transfer unit 33 can be implemented in software by the computer group 32.

[0015] The central site 4 houses a controller 41, a computer group 42, a transfer unit 43, and a management database (DB) 44. The controller 41 and the transfer unit 43 have the same functions as the controller 31 and the transfer unit 33. In Figure 1, for the sake of understanding this embodiment, the controller 41, the transfer unit 43, and the management DB 44 are shown as separate from the computer group 42, but these can also be implemented in software by the computer group 42.

[0016] In this embodiment, "components" are created for each WD1 or group of WD1s. A component is a set of various types of NFs necessary to provide services to WD1, and is realized software-wise on computer clusters 32 and 42. Below, the case of creating components for individual WD1s will be described as an example. In the case of components of a group of WD1s, the "identification information" in the following description will be the identification information assigned to the group of WD1s, rather than the identification information of individual WD1s.

[0017] Figure 2 is a sequence diagram when WD1 requests registration to the mobile communication network 42 in a state where components of WD1 have not been created. Note that since RU2 only relays signals between WD1 and the computer cluster 32 of the edge site 3, RU2 is omitted in Figure 2. At S1, WD1 transmits a registration request message including the identification information of WD1. The identification information is, for example, SUPI (Subscription Permanent Identifier). The registration request message is input to the transfer unit 33 within the computer cluster 32. The transfer unit 33 holds information indicating the relationship between the identification information and the components generated in the computer cluster 32. In this example, since the components of WD1 have not been generated, the transfer unit 33 does not manage the identification information included in the registration request message. In this case, at S2, the transfer unit 33 transfers the registration request message to the controller 31.

[0018] In response to receiving the registration request message, at S3, the controller 31 transmits a component information request message to the management DB 44 of the central site 4. The component information request message includes the identification information of WD1. The management DB 44 holds component information indicating the relationship between the identification information and the NFs to be included in the component. The management DB 44 also has an authentication function for WD1. When the authentication of WD1 is successful, at S4, the management DB 44 transmits the component information of WD1 to the controller 31.

[0019] In S5, the controller 31 generates the components of WD1 in the computer cluster 32 according to the received component information. According to FIG. 2, the components of WD1 include DU, CU, UPF, SMF, AMF, and a state management unit (state management function). Note that DU is the general term for DU-CP and DU-UP, and CU is the general term for CU-CP and CU-UP. The state management unit centrally manages the state information of WD1 that was conventionally managed individually by each NF such as AMF and SMF. The state information can be in the form of, for example, UE context or SM context. In S5, when the components of WD1 are generated, the state management unit has the initial value of the state information of WD1. The initial value can be, for example, part or all of the state information of WD1 when the components of WD1 were deleted last time. The initial value is stored in the management DB 44 as described later and is included in the component information received by the controller 1 in S4. In the following description, unless otherwise specified, "component" refers to the components of WD1.

[0020] In S6, the controller 31 transmits a registration request message to the CU via the DU of the component. Along with the registration of WD1, the CU (CU-CP) of the component updates the state information of WD1 stored in the state management unit, for example, the UE context, in S7. When the state information of WD1 is updated, the CU of the component transmits a registration response message to the controller 31 via the DU in S8. This registration response message is transmitted to WD1 via the transfer unit 33. Note that the transfer unit 33 stores information indicating the relationship between the identification information of WD1 and the component in response to the reception of the registration response message.

[0021] Figure 3 is a sequence diagram showing the process when WD1 requests registration with the mobile communication network 42 while its components have been created. The process in Figure 3 may occur, for example, when WD1 transitions from a connected state to an idle state or another state after its components have been created, and then reconnects to the mobile communication system. In S10, WD1 sends a registration request message containing its identification information. The registration request message is input to the transfer unit 33, as in Figure 2. Since the transfer unit 33 holds the identification information of WD1, in S11 it sends the registration request message to the CU via the component's DU.

[0022] Upon registration of WD1, the component's CU updates the WD1 state information stored in the state management unit, such as the UE context, in S12. After updating the WD1 state information, the component's CU sends a registration response message to WD1 via the DU and the transfer unit 33 in S13. Note that the component's CU (CU-CP) may be configured to authenticate WD1 by sending the WD1 identification information to the management DB 44 before updating the state information in S12.

[0023] Random access procedures that may be executed before S1 in Figure 2 or S10 in Figure 3 are processed by the controller 31 regardless of whether the components of WD1 have been created or not. In other words, the transfer unit 33 outputs the signals for random access procedures received from WD1 via RU2 to the controller 31.

[0024] Figure 4 is a sequence diagram of the process by which WD1 deletes a component. In S20, WD1 sends a termination request (deletion request) message containing WD1's identification information. The termination request message is input to the transfer unit 33 within the computer group 32. Since the transfer unit 33 holds WD1's identification information, in S21 it sends the termination request message to the CU via the DU of WD1's component.

[0025] Upon receiving a termination request message, the component's CU (CU-CP) retrieves the state information of WD1 from the state management unit in S22, and performs state storage processing in S23 to store the state information in the management DB44. The state information stored in the management DB44 may be, for example, state information that is specified to be retained in the 3GPP (registered trademark) standard. Alternatively, instead of the CU retrieving the state information from the state management unit and storing it in the management DB44, the CU may instruct the state management unit to execute the state storage processing, and the state management unit may perform the state storage processing.

[0026] Once the state storage process is complete, the component's CU sends a termination response message to the controller 31 in S24. The termination response message includes the identification information of WD1. In response to the termination response message, the controller 31 deletes the component of WD1. After deleting the component of WD1, the controller 31 sends a termination response message to WD1 via the transfer unit 33 in S26. The transfer unit 33 also deletes the information indicating the relationship between the identification information of WD1 and the component in response to the termination response message.

[0027] Furthermore, component deletion can be performed not only when WD1 explicitly requests it from the mobile communication network, but also by a timer managed by the network. For example, if WD1 transitions to an idle state and a predetermined period of time elapses without WD1 reconnecting, the controller 31 can be configured to delete the components of WD1.

[0028] Furthermore, Figure 2 illustrates the sequence when WD1 requests registration with the mobile communication network 42 while its components have been created. As explained using Figure 4, the components of WD1 are deleted by explicit processing by WD1 or by the expiration of a timer. Since the time remaining until the timer expires is also known to WD1, WD1 can determine whether or not its components are maintained in the mobile communication network. Therefore, the process in Figure 2 can be reinterpreted not as a registration process to the mobile communication network, for example, but as a reconnection process. In this case, WD1 may be configured to send a reconnection message in S10 instead of a registration request message. The reconnection message also includes the identification information of WD1.

[0029] Figure 5 is a sequence diagram of the PDU session establishment process for WD1. PDU session establishment is performed after the registration process shown in Figures 2 and 3. Since the WD1 component has been created, the control signals transmitted by WD1 are forwarded to other NFs via RU2, the forwarding unit 33, and the component's CU-CP. In Figure 5, RU2, the forwarding unit 33, and the CU-CP are omitted for simplification.

[0030] In S30, WD1 sends a PDU session establishment request message. The PDU session establishment request message is forwarded to AMF via CU-CP. In S31, AMF selects an SMF to perform the PDU session establishment process, and in S32, instructs the selected SMF to establish the PDU session. In S33, SMF updates the state information of WD1 stored in the state management unit, for example, the SM context. In S34, SMF selects a UPF in the PDU session path, and in S35, instructs the UPF to establish the PDU session. Once the PDU session establishment is complete, SMF updates the state information of WD1 stored in the state management unit, for example, the SM context, in S36. After updating the state information of WD1 stored in the state management unit, SMF sends a PDU session establishment response message to WD1 via CU-CP in S37.

[0031] Conventionally, each NF managed its own state information, requiring the transmission and reception of state information between NFs when updating it. For example, as explained in Figure 5, instead of processing S33, state information was transmitted and received between the AMF and SMF. Similarly, instead of processing S36, state information was transmitted and received between the AMF and SMF. In this embodiment, since the state information of WD1 is centrally managed by the state management unit, there is no need to transmit and receive state information between NFs, and the processing load on each NF can be reduced.

[0032] Furthermore, NF (Network Functions) are scaled out or scaled in to cope with increases or decreases in processing load. If NF manages state information, it is necessary to scale out while maintaining state information, but scaling out while maintaining state information is difficult. On the other hand, in this embodiment, the state information of WD1 is centrally managed by the state management unit, making it easier to scale out NF.

[0033] Furthermore, conventionally, WD1, as an NF of the CP within the core network, only transmitted and received control signals with AMF, and did not directly transmit or receive control signals with, for example, SMF. In this embodiment, in S37, SMF transmits a control signal to WD1 without going through AMF. In this way, by not using AMF as a mere relay function for control signals, the processing load on AMF can be reduced. Also, control signals transmitted and received between NFs regarding WD1 and groups of WD1 are basically transmitted and received within the component. Therefore, congestion of CP due to the transmission and reception of control signals can be avoided.

[0034] Furthermore, the types of NFs included in the components generated for each WD1 and each group of WD1s, as well as the number of each type of NF, may differ for each WD1 and group. It is also possible to divide the function of a single NF into multiple parts and configure the combination of NF functions included in the components of WD1s and groups to be different. For example, one of the functions performed by an AMF is location management (mobility management) of WD1s. Therefore, if a WD1 is an IoT device or the like that is fixedly installed in a predetermined location, the AMF component of that IoT device may not have a location management function.

[0035] Furthermore, in the above embodiment, the components were generated in the computer group 32 at edge site 3. However, it is also possible to configure the system to generate the components in the computer group 42 at central site 4. For example, the system can be configured to basically generate the components in the computer group 32 at edge site 3, and if the components cannot be generated in the computer group 32 at edge site 3 due to insufficient resources, the components can be generated in the computer group 42 at central site 4. If the components cannot be generated in the computer group 32 at edge site 3, the controller 31 at edge site 3 forwards the registration request message received in S2 of Figure 2 to the controller 41 at central site 4. Note that if WD1 and groups are assigned priorities, and the computer group 32 at edge site 3 does not have the resources to generate high-priority components such as WD1, the system can be configured to generate high-priority components in the computer group 32 at edge site 3 by moving existing lower-priority components to central site 4. Furthermore, it is also possible to configure the system so that some of the multiple NFs included in the component are generated on the computer cluster 32 at edge site 3, and the remaining NFs are generated on the computer cluster 42 at central site 4.

[0036] <Summary> Figure 6 is a diagram showing the configuration of the mobile communication network 500 according to this embodiment. The mobile communication network comprises a computer group 5 and one or more RU2 connected to the computer group 5. The computer group 5 is a collective term for the computer group 32 at the edge sites and the computer group 42 at the central site shown in Figure 1. In other words, the computer group 5 is a collective term for one or more computers located at various sites of the mobile communication network 500.

[0037] The computer group 5 implements the determination unit 51 and the processing unit 52 in software. The determination unit 51 is a collective term for the transfer unit 33 and the transfer unit 43 in Figure 1, and is provided, for example, at each site of the mobile communication network 500. The processing unit 52 is a collective term for the controller 31 and the controller 41 in Figure 1, and is provided, for example, at each site of the mobile communication network 500. The management DB 53 corresponds to the management DB 44 in Figure 1. The management DB 44 may also be provided at multiple sites. The component group 54 is a collective term for WD1 and components provided specifically for groups of WD1.

[0038] When the determination unit 51 receives a first request message from WD1 via RU2 requesting registration or reconnection to the mobile communication network 500, it determines, based on the identification information contained in the first request message, whether the component associated with the identification information has been generated in the computer group 5. If the determination unit 51 determines that the component associated with the identification information has been generated in the computer group 5 of the mobile communication network 500, it outputs the first request message to the component associated with the identification information.

[0039] On the other hand, if the processing unit 52 determines that a component associated with the identification information has not been generated in the computer group 5 of the mobile communication network 500, the processing unit 52 performs the process of generating the component associated with the identification information in the computer group 5 of the mobile communication network 500. The management DB 53 stores the information about which NFs to include in the component and the initial values ​​of the state information to be stored in the state management unit as component information. In other words, the processing unit 52 generates the component according to the component information for each piece of identification information held by the management DB 53.

[0040] Furthermore, when the processing unit 52 receives a second request message from WD1 requesting the deletion of a component, it performs the process of deleting the component associated with the identification information contained in the second request message from the computer group 5.

[0041] In this way, by generating a dedicated NF for each WD1 or group of WD1s, it becomes possible to reduce the number of WD1s affected in the event of an NF failure.

[0042] Furthermore, as described above, the component associated with the identification information has a state management unit, which centrally manages the state information of WD1 that uses the identification information. Therefore, the NF (other than the state management unit) of the component associated with the identification information does not hold state information. The NF refers to the state information stored in the state management unit, and when the state of WD1 changes, it updates the state information stored in the state management unit. In this way, by centrally managing state information in the state management unit, the processing load on the NF can be reduced, and the NF can be easily scaled out.

[0043] Furthermore, the NF, which is different from the component's AMF, does not use the AMF solely for relaying control plane messages when sending and receiving them. This configuration reduces the processing load on the AMF.

[0044] The invention is not limited to the embodiments described above, and various modifications and changes are possible within the scope of the gist of the invention.

[0045] This configuration makes it possible to mitigate the impact of NF failures. Therefore, it becomes possible to contribute to Goal 9 of the United Nations Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote sustainable industrialization and foster innovation." [Explanation of Symbols]

[0046] 500: Mobile communication network, 5: Computer group, 51: Decision unit, 52: Processing unit, 54: Component group

Claims

1. A mobile communication network, When a first request message is received from a wireless device requesting registration or connection to the mobile communication network, a determination means determines, based on the identification information contained in the first request message, whether a component associated with the identification information has been generated in the computer group of the mobile communication network. If the determination means determines that the component associated with the identification information has not been generated in the group of computers of the mobile communication network, the processing means performs a process to generate the component associated with the identification information in the group of computers of the mobile communication network. Equipped with, The component associated with the identification information has one or more network functions dedicated to one or more wireless devices that use the identification information. The aforementioned one or more network functions include one or more distributed units (DUs) and central units (CUs) in a mobile communication network.

2. The mobile communication network according to claim 1, wherein the determination means determines that the component associated with the identification information has been generated in the group of computers of the mobile communication network, and outputs the first request message to the component associated with the identification information.

3. The mobile communication network according to claim 1, wherein when the processing means receives a second request message from the wireless device, it performs a process of deleting the component associated with the identification information contained in the second request message from the group of computers.

4. The mobile communication network according to claim 1, wherein the component associated with the identification information further has storage means for storing state information of one or more wireless devices that use the identification information, and the one or more network functions of the component associated with the identification information do not hold the state information.

5. The mobile communication network according to claim 4, wherein one or more network functions of the component associated with the identification information refer to the state information stored in the storage means, and when the state of one or more wireless devices changes, the state information stored in the storage means is updated.

6. The mobile communication network according to claim 1, wherein the determination means and the processing means are implemented in the computer group.

7. The mobile communication network according to claim 6, wherein the group of computers receives the first request message from the wireless device via a wireless unit (RU) that transmits and receives wireless signals.

8. The mobile communication network according to any one of claims 1 to 7, wherein the one or more network functions further include one or more of the following: user plane functions (UPF), access and mobility functions (AMF), and session management functions (SMF).

9. The one or more network functions mentioned above include the AMF, The mobile communication network according to claim 8, wherein one or more of the network functions, which are different from the AMF, does not use the AMF solely for relaying control plane messages when sending and receiving such messages.

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