JP7436586B1 - Information processing equipment and programs - Google Patents

Abstract

An object of the present invention is to realize a technology that makes it possible to quickly determine that a terminal is located out of service area. [Solution] In the registration management state of a terminal managed by the core network, the state of the terminal is a registration state indicating that it is registered with the core network, and in the connection management state of the terminal managed by the core network. , if the state of the terminal is an idle state indicating that the connection between the terminal and the control plane function of the core network has not been established, a measurement unit that measures the duration of the idle state; (73), a transmission control unit (74) that causes the core network to transmit a polling message requesting a response from the terminal to the core network when the measured duration exceeds a threshold; and a threshold setting unit (75) that sets a threshold for each terminal based on information acquired from the core network. [Selection diagram] Figure 5

Description

The present invention relates to an information processing apparatus and a program, and more particularly, to an information processing apparatus and a program that make it possible to quickly determine that a terminal is located outside the service area.

In the 5G core network, for example, an Access and Mobility Management Function (AMF) manages the connection state of a terminal as an RM (Registration Management) state and a CM (Connection Management) state. 3GPP. According to TS23.501, the duration of the RM-REGISTERED state is measured by the T3512 timer starting from the time when the RM state transitions from RM-DEREGISTERED to RM-REGISTERED or when Registration Updated Accept is performed. Then, when the timer expires, the RM state is transitioned from RM-REGISTERED to RM-DEREGISTERED. Thereby, the 5G core network can know that the terminal is located outside the service area.

Additionally, a technology has been proposed that allows the application server to appropriately check the location of the terminal even if the location of the terminal changes multiple times within the minimum reporting interval specified by the application server while monitoring location reporting events. (For example, see Patent Document 1).

JP2022-521224A

In recent years, the services provided by application servers connected to the 5G core network have diversified, and there is a growing need to quickly determine whether communication with a terminal is possible. In particular, for terminals that are remotely controlled, terminals that are attached to moving objects, aircraft, etc., it is necessary to determine whether communication with the terminal is possible or not in a shorter period of time.

However, in the conventional technology as described above, there is a problem in that it is not possible to know that the terminal is located outside the service area until the T3512 timer expires.

One aspect of the present invention aims to realize a technology that allows it to be quickly determined that a terminal is located outside the service area.

An information processing device according to one aspect of the present invention is an information processing device connected to a core network, and in a registration management state of a terminal managed by the core network, the state of the terminal is registered in the core network. and in the connection management state of the terminal managed by the core network, the state of the terminal is that the connection between the terminal and the control plane function of the core network is not established. a measuring unit that measures the duration of the idle state when the terminal is in an idle state, and a response from the terminal to the core network when the measured duration exceeds a threshold; a transmission control unit that causes the core network to transmit a polling message requesting the terminal to the terminal; and a threshold setting that sets the threshold value for each terminal based on information obtained from the core network corresponding to the terminal. It is equipped with a section.

Each aspect of the present invention may be realized by a computer, and in this case, a program for realizing the system on the computer by operating the computer as each part (software element) included in the above system, and a program recorded thereon. Computer readable recording media also fall within the scope of the present invention.

According to one aspect of the present invention, it is possible to realize a technique that allows the user to quickly determine that a terminal is located outside the service area.

1 is a diagram illustrating a configuration example of a conventional 5G network communication system. FIG. 2 is a state transition diagram of a CM state and an RM state in AMF defined in 3GPP TS23.501. FIG. 2 is a diagram illustrating states of a terminal corresponding to CM states and RM states managed by AMF. 1 is a diagram illustrating a configuration example of a 5G network communication system according to an embodiment of the present invention. FIG. 2 is a block diagram showing an example of a functional configuration of an out-of-service area determination control device. 12 is a flowchart illustrating a flow of an example of out-of-service determination processing. 12 is a flowchart illustrating the flow of an example of a threshold value etc. setting process. 12 is a flowchart illustrating a flow of an example of a threshold value etc. setting process. It is a figure explaining the variation regarding the setting of T_polling, N_polling, and T_wait. FIG. 2 is a diagram illustrating an example of the configuration of a computer that executes instructions of a program that is software that implements each function.

<First embodiment>
(Conventional 5G network communication system)
First, a conventional 5G network communication system will be described.

FIG. 1 is a diagram showing a configuration example of a conventional 5G network communication system 10. In the 5G network communication system 10 shown in the figure, the terminals 21-1 to 21-3 can communicate with the application server 60 via the core network 50. Note that if there is no need to distinguish the terminals 21-1 to 21-3 individually, they will be collectively referred to as the terminals 21. Further, the terminal is also referred to as UE (User Equipment).

Terminal 21 is connected to core network 50 via base station 41 . The base station 41 is installed corresponding to a cell 42 that is a communication area of the base station 41. Although only one base station 41 is shown in FIG. 1, there are actually many more base stations and cells corresponding to those base stations. Furthermore, a TA (Tracking Area) consisting of a plurality of cells is defined, and the terminal 21 can detect which TA the base station 41 belongs to.

The core network 50 includes an AMF (Access and Mobility management function) 51 and a NEF (Network Exposure Function) 52. Note that the AMF 51 and the NEF 52 are part of a control plane function (CPF) group related to control processing such as establishing communication. A user plane function (UPF) 53 executes processing for transmitting and receiving user data.

The application server 60 is connected to the NEF 52 and UPF 53 of the core network 50.

In the example of FIG. 1, the terminal 21-1 is communicating with the application server 60. That is, the terminal 21-1 transmits and receives data related to the control plane to and from the application server 60 via the base station 41, AMF 51, and NEF 52. Furthermore, the terminal 21-1 transmits and receives data related to the user plane to and from the application server 60 via the base station 41 and the UPF 53.

In the example of FIG. 1, the terminal 21-2 and the terminal 21-3 are not communicating with the application server 60.

The AMF 51 manages a CM (Connection Management) state, which is a connection management state of the terminal 21 .

When the terminal 21 is connected to the AMF 51 through the N1 interface, the CM state of the terminal 21 is CM-CONNECTED. That is, when a connection is established between the terminal 21 and the control plane function of the core network 50 (AMF 51 in this example) by NAS (Non-Access-Stratum) signaling, the CM state of the terminal 21 is CM- It becomes CONNECTED.

On the other hand, when the terminal 21 is not connected to the AMF 51 through the N1 interface, the CM state of the terminal 21 becomes CM-IDLE. That is, if a connection by NAS signaling is not established between the terminal 21 and the control plane function of the core network 50 (AMF 51 in this example), the CM state of the terminal 21 becomes CM-IDLE.

In the example of FIG. 1, the CM state of the terminal 21-1 is CM-CONNECTED, and the CM states of the terminals 21-2 and 21-3 are CM-IDLE.

The AMF 51 also manages the RM (Registration Management) state, which is the registration management state of the terminal 21 .

If the terminal 21 is registered in the core network 50, the RM state of the terminal 21 is RM-REGISTERED, and if the terminal 21 is not registered in the core network 50, the RM state of the terminal 21 is RM-DEREGISTERED. .

When the RM state is RM-REGISTERED, the terminal 21 provides the AMF 51 with information representing its own location. For example, when the TA to which the cell corresponding to the base station with which the wireless link has been established changes due to movement of the terminal 21, the terminal 21 transmits the identification information of the new TA to the AMF 51. The process in which the terminal 21 updates the information of the TA to which its own cell belongs is referred to as NAS Mobility Update or Mobility Registration Update.

When the RM state is RM-DEREGISTERED, the core network 50 cannot detect the location of the terminal 21 and therefore cannot reach the terminal 21.

In the example of FIG. 1, it is assumed that the RM states of the terminals 21-1 to 21-3 are RM-REGISTERED.

3GPP TS23.501 specifies details of the CM state and RM state (5.3.2, 5.3.3). FIG. 2 shows a state transition diagram of the CM state and RM state in the AMF 51 as defined by 3GPP TS23.501.

As shown in FIG. 2, when the N2 Context is released, the CM state managed by the AMF 51 transitions from CM-CONNECTED to CM-IDLE. When the N2 Context is established, the CM state managed by the AMF 51 transitions from CM-IDLE to CM-CONNECTED.

Further, when Deregistration Registration is rejected, the RM state managed by the AMF 51 changes from RM-REGISTERED to RM-DEREGISTERED. Further, when Registration is accepted, the RM state managed by the AMF 51 changes from RM-DEREGISTERED to RM-REGISTERED. On the other hand, if Registration Update is accepted, the RM state managed by AMF 51 does not transition from RM-REGISTERED, and if Registration is rejected, the RM state managed by AMF 51 does not transition from RM-DEREGISTERED.

FIG. 3 is a diagram illustrating the states of the terminal 21 corresponding to the CM state and RM state managed by the AMF 51. When the CM state is CM-IDLE and the RM state is RM-DEREGISTERED, the terminal 21 is powered off or located out of range, that is, outside the cell 42. When the CM state is CM-CONNECTED and the RM state is RM-REGISTERED, the terminal 21 is in communication. When the CM state is CM-IDLE and the RM state is RM-REGISTERED, the terminal 21 is on standby.

In the example of FIG. 1, the CM states of the terminals 21-2 and 21-3 are CM-IDLE, and when viewed from the core network 50, the terminals 21-2 and 21-3 are recognized as being on standby. However, in reality, the terminal 21-3 is located outside the cell 42, outside the service area, and the core network 50 cannot reach the terminal 21-3.

According to the 3GPP regulations, the AMF 51 determines the duration of the RM-REGISTERED state using the T3512 timer, starting from the time when the terminal 21-3 transitions from RM-DEREGISTERED to RM-REGISTERED, or from the time when Registration Updated Accept is made. Monitored by If the Registration Update from the UE to the AMF still does not occur even after the T3512 timer expires, the AMF 51 transitions the RM state of the terminal 21-3 to RM-DEREGISTERED.

Normally, the expiration time of the T3512 timer is 54 minutes, and even if the terminal 21-3 is located outside the service area during this time, the core network 50 recognizes the terminal 21-3 as being on standby.

In recent years, the services provided by the application server 60 connected to the 5G core network have been diversified, and there is a growing need to quickly determine whether communication with the terminal 21 is possible. In particular, for terminals that are remotely controlled, terminals that are attached to moving objects, aircraft, etc., it is necessary to determine whether communication with the terminal is possible or not in a shorter period of time.

However, conventionally, it was not possible to know that the terminal was located outside the service area until the T3512 timer expired.

(5G network communication system according to this embodiment)
FIG. 4 is a diagram illustrating a configuration example of a 5G network communication system according to the present embodiment. Note that components having the same functions as those described with reference to FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

In the example of FIG. 4, the 5G network communication system 10 is provided with an out-of-service area determination control device 70. The out-of-service area determination control device 70 is connected to the AMF 51 and the NWDAF (Network Data Analysis Function) 54 of the core network 50 . Roughly speaking, the out-of-service area determination control device 70 is a device that determines whether or not the terminal 21-3 is located outside the service area, without waiting for the expiration of the T3512 timer, and notifies the core network 50 of the determination. Further, the out-of-service area determination control device 70 sets a threshold value used for the above-described determination for each terminal 21 based on the information acquired from the AMF 51 and the NWDAF 54. As an example, the out-of-service area determination control device 70 can be configured by a general-purpose computer.

(Example of configuration of out-of-service determination control device 70)
FIG. 5 is a block diagram showing an example of the functional configuration of the out-of-service area determination control device 70. In the example shown in the figure, the out-of-service area determination control device 70 includes a general control section 71, a state confirmation section 72, a duration measurement section 73, a transmission control section 74, a threshold value setting section 75, and a determination section 76.

The general control unit 71 controls the processing of each unit constituting the out-of-service area determination control device 70, and also performs control related to data transmission and reception with the core network 50. The state confirmation unit 72 acquires the CM state and RM state of the terminal 21 via the AMF 51 or the NEF. When the CM state acquired by the state confirmation unit 72 is CM-IDLE and the RM state is RM-REGISTERED, the duration measuring unit 73 calculates the duration for which the CM state is CM-IDLE. Measure the duration.

When the duration measured by the duration measurement unit 73 exceeds a preset threshold, the transmission control unit 74 sends a polling message requesting a response from the terminal 21 to the core network 50 from the core network 50 to the terminal 21. have it sent to The threshold value setting unit 75 sets a threshold value used for the above-described determination for each terminal 21 based on the information acquired from the AMF 51 and the NWDAF 54.

In this way, in the registration management state of the terminal 21 managed by the core network 50, the out-of-service area determination control device 70 sets the registration state (RM-REGISTERED) indicating that the terminal 21 is registered in the core network 50. , and in the connection management state of the terminal managed by the core network, the state of the terminal 21 is an idle state (CM - IDLE), a duration measuring unit 73 that measures the duration of the idle state, and a response from the terminal 21 to the core network 50 if the measured duration exceeds a threshold. a transmission control unit 74 that causes the core network 50 to transmit a polling message requesting the terminal 21 from the core network 50 to the terminal 21; and a threshold setting that sets a threshold value for each terminal 21 based on information acquired from the core network 50 corresponding to the terminal 21. 75.

Further, the determination unit 76 determines the state regarding whether or not the terminal 21 can be reached. For example, after a predetermined waiting time has elapsed after transmitting the polling message, the determination unit 76 determines that the state of the terminal in the connection management state is that the connection between the terminal and the control plane function of the core network has been established. If the terminal does not change to the connected state (CM-CONNECTED), it is determined that the terminal is located outside the service area.

(Flow of out-of-service determination processing)
Next, an example of the out-of-service area determination process executed by the out-of-service area determination control device 70 will be described with reference to FIG. FIG. 6 is a flowchart illustrating the flow of an example of out-of-service area determination processing.

In step S31, the comprehensive control unit 71 identifies a terminal to be determined as being out of service area. The terminal to be determined as being out of service area is specified based on a request from the application server 60, for example. For example, when there is a request from the application server 60 to determine that the terminal 21-3 is out of service area, in step S31, the identification information of the terminal 21-3 is acquired via the core network 50, and the out of service determination is made. The target terminal is identified.

In step S32, the state confirmation unit 72 acquires the CM state and RM state of the terminal identified in step S31 via the AMF 51 or the NEF 52.

In step S33, the state confirmation unit 72 determines whether the RM state acquired in step S32 is RM-REGISTERED. If it is determined in step S33 that it is not RM-REGISTERED, the process of step S34 is executed. In this case, the RM state is RM-DEREGISTERED. In step S34, the determination unit 76 determines that the terminal identified in step S31 is powered off.

If it is determined in step S33 that it is RM-REGISTERED, the process in step S35 is executed. In step S35, the state confirmation unit 72 determines whether the CM state acquired in step S72 is CM-IDLE. If it is determined in step S35 that it is not CM-IDLE, the process returns to step S32 and subsequent processing is executed. In this case, the CM state is CM-CONNECTED.

If it is determined in step S35 that it is CM-IDLE, the process in step S36 is executed. In step S36, the duration measuring unit 73 starts measuring the duration of the CM state being CM-IDLE, in other words, the duration of the CM state not changing.

In step S37, the duration measurement unit 73 determines whether the duration time measurement started in step S36 exceeds a threshold value. Although the details will be described later, the threshold used here is the threshold set for each terminal identified in step S31.

For example, if the threshold is 3 minutes, and the state in which the CM state does not transition continues for more than 3 minutes after the start of measurement of the duration, it is determined in step S37 that the duration exceeds the threshold; The process of step S38 is executed.

On the other hand, if the CM state changes within 3 minutes after the start of measurement of the duration, it is determined in step S37 that the duration does not exceed the threshold. In this case, since the CM state has already transitioned to CM-CONNECTED, the process returns to step S32.

In step S38, the transmission control unit 74 causes the core network 50 to transmit the C-Plane message. Here, the C-Plane message is an example of a polling message that requests a response from the terminal 21 to the core network 50. Further, as an example, the C-Plane message may be an SMS, NIDD, or a PDU session modification command. When such a message is received by the terminal 21, the terminal 21 responds to the core network 50, so that the CM state of the terminal 21 changes from CM-IDLE to CM-CONNECTED.

Note that the polling message is not limited to the C-Plane message; for example, a U-Plane message such as Ping may be sent from the core network 50 to the terminal 21 as the polling message. That is, if the CM state of the terminal 21 that received the message changes from CM-IDLE to CM-CONNECTED, it can be used as a polling message.

After the process in step S38, it is determined in step S39 whether a predetermined waiting time has elapsed.

In step S40, the state confirmation unit 72 obtains the CM state of the terminal identified in step S31. In step S41, the state confirmation unit 72 determines whether the CM state acquired in step S40 is CM-IDLE.

If it is determined in step S41 that the terminal 21 is CM-IDLE, this means that the CM state of the terminal 21 has transitioned from CM-IDLE to CM-CONNECTED, and the process returns to step S32.

Note that the CM state is changed after waiting for the time required for the state transition of the terminal 21 in response to the C-Plane message to be reflected in the CM state managed by the AMF 51 (i.e., the waiting time in step S39) to elapse. A determination is made as to whether or not CM-IDLE is CM-IDLE. Therefore, a determination as to whether the terminal 21 is located outside the service area is made after a predetermined waiting time has elapsed after the polling message was sent.

The waiting time may be, for example, a predetermined time. Further, if the time required for the transition of the state of the terminal 21 to be reflected in the CM state managed by the AMF 51 is sufficiently short, the process of step S39 may be skipped.

If it is determined in step S41 that it is CM-IDLE, the process in step S42 is executed. In step S42, the determination unit 76 determines that the terminal identified in step S31 is located outside the service area. For example, in the terminal 21-3 shown in FIG. 4, the RM state managed by the AMF 51 is RM-REGISTERED, but in step S42, it is determined that the terminal 21-3 is located outside the service area. .

As an example, the determination result in step S42 is transmitted by the general control unit 71 to the NEF 52, and the NEF 52 transmits information indicating that the terminal 21-3 is located outside the service area to the application server 60. That is, the terminal 21 communicates with the application server 60 via the core network 50, and the core network 50 provides the application server 60 with the determination result of the determination unit 76.

Further, the determination result of step S42 may be transmitted by the comprehensive control unit 71 to the NF (Network Function) forming the core network such as the AMF 51, the SMF (Session Management Function), and the NWDAF 54, or to the application server 60. In this case, since the AMF 51 can detect that the terminal 21-3 is located outside the service area, the RM state of the terminal 21-3 may be changed from RM-REGISTERED to RM-DEREGISTERED.

In this way, the out-of-service area determination process by the out-of-service area determination control device 70 is executed. By executing the out-of-service area determination process, the application server 60 can detect that the terminal 21, which is recognized as being on standby by the core network 50, is actually located outside the service area.

(Flow of threshold value etc. setting process)
Next, details of the threshold used in step S37 in FIG. 6 will be explained. This threshold value is set for each terminal by the threshold value setting unit 75 of the out-of-service area determination control device 70.

FIGS. 7 and 8 are flowcharts illustrating the flow of an example of the threshold value etc. setting process. This process may be executed, for example, prior to execution of the process shown in FIG. 6, or during the process shown in FIG. 6. For example, threshold value setting processing may be performed between step S35 and step S36 in FIG.

In step S61 of FIG. 7, the threshold value setting unit 75 acquires attribute information of the terminal 21 corresponding to the threshold value to be set. For example, when a threshold value used for out-of-service determination processing for the terminal 21-3 is set, attribute information of the terminal 21-3 is acquired. As an example, the attribute information may be information representing the purpose of the terminal, but is not limited to this.

The attribute information indicating the purpose of the terminal is, for example, information that specifies whether the terminal is a smartphone, an IoT device, a terminal attached to a moving object such as a car or a drone, or a terminal attached to a flying object. . Further, the attribute information may include the content of the service that each terminal has contracted with the carrier that operates the core network 50. For example, the attribute information is transmitted from the terminal 21 to the CPF of the core network 50 and provided to the out-of-service determination control device 70.

In step S62, the threshold setting unit 75 determines the priority based on the attribute information. For example, if the purpose of the terminal is indicated to be a terminal used for emergency communications, or if it is indicated to be a terminal that is attached to a mobile or flying object and is remotely controlled, Communication has high priority. On the other hand, if the usage of the terminal indicates that it is a normal smartphone and is a terminal that has a low fee contract with a carrier, the communication priority of the terminal is low. For example, the threshold setting unit 75 has a table that identifies priorities corresponding to attribute information, and here, the attribute information acquired in step S61 has three priorities: high, medium, and low. shall be classified into degrees.

In this way, the threshold setting unit 75 identifies the priority of communication of the terminal within the core network based on the attribute information, and sets the threshold according to the priority.

If it is determined in step S62 that the priority is high, the process in step S64 is executed. In step S64, the threshold value setting unit 75 sets the value of the threshold value T_polling to the same value (T_RLF×1) as the radio link failure determination time T_RLF required for the terminal to determine a wireless link failure.

The terminal 21 is configured to detect the reception quality of the reference signal transmitted from the base station 41 at predetermined intervals (for example, 100 ms) so that it can detect whether it is located outside the service area. . When the received quality of the reference signal falls below a predetermined threshold, out-of-sync indicating that the received quality has decreased is detected. When this out-of-sync is detected consecutively a predetermined number of times (N310), a timer (T310) for determining radio link failure (RLF) is started. If the reception quality of the reference signal does not exceed the threshold before the timer 310 expires, the terminal 21 determines that there is a wireless link failure with the base station 41. That is, the value of the radio link failure determination time T_RLF is calculated by N310×100ms+T310. Note that the value of N310 and the value of T310 are set by the CPF of the core network 50 or the base station.

Furthermore, if it is determined in step S62 that the priority is low, the process in step S66 is executed. In step S66, the threshold setting unit 75 sets the value of the threshold T_polling to 1/2 (T3512×0.5) of the time set by the timer T3512. Note that in step S66, the threshold setting unit 75 may set the value of the threshold T_polling to T_RLF×100.

In this way, the threshold value setting unit 75 acquires attribute information, which is information related to the purpose of the terminal, from the core network 50, and sets a threshold value based on the attribute information. Further, the threshold value is determined by multiplying the determination time required to determine a wireless link failure by a predetermined coefficient when the terminal 21 receives a signal transmitted from a base station with reception quality lower than a preset quality value. A predetermined coefficient is determined based on information obtained from the core network 50 corresponding to the terminal 21.

On the other hand, if it is determined in step S62 that the priority is intermediate ("middle"), the process of step S63 is executed. In step S63, the threshold setting unit 75 acquires the UE location and behavior of the terminal 21.

The UE location is information related to the location of the terminal 21, and is, for example, TA information representing a TA (Tracking Area) to which the base station 41 corresponding to the cell 42 covering the terminal 21 belongs.

The behavior is information obtained based on the analysis result by the NWDAF 54. The NWDAF 54 collects and analyzes data from, for example, NF (Network Function) and OAM (Operation Administration and Management) of the core network 50. By referring to the behavior, it is possible to specify, for example, the moving speed and communication frequency of the terminal.

In this way, the threshold setting unit 75 further acquires behavior information, which is information related to the moving speed and communication frequency of the terminal 21, and position information related to the location of the terminal, from the core network 50, and acquires attribute information, behavior information, and Set a threshold based on location information.

After the process in step S63, in step S65, the threshold setting unit 75 specifies the TA and moving speed of the terminal 21 by referring to the behavior acquired in step S63.

In step S67, the threshold setting unit 75 determines the geographical extent of the TA identified in step S65. The geographical size of a TA is determined, for example, as the size of the area covered by the cells of the base stations included in the TA; for example, if the area is larger than a preset threshold, the TA is determined to be wide. , if the area is smaller than the threshold, it is determined that the TA is narrow. If it is determined in step S67 that the TA is wide, the process in step S68 is executed.

In step S68, the threshold setting unit 75 determines whether the moving speed of the terminal 21 identified in step S65 is high or low. For example, if the moving speed of the terminal 21 is faster than a preset threshold, it is determined that the moving speed is high, and if the moving speed of the terminal 21 is slower than the threshold, it is determined that the moving speed is slow. Note that when the terminal is stopped, that is, when the moving speed is 0 km, the moving speed is determined to be low.

If it is determined in step S68 that the moving speed is low, the process in step S70 is executed. In step S70, the threshold value setting unit 75 calculates the value of the temporary threshold value P by T_RLF×1.

On the other hand, if it is determined in step S68 that the moving speed is high, the process in step S71 is executed. In step S71, the threshold value setting unit 75 calculates the value of the temporary threshold value P by T_RLF×4.

On the other hand, if it is determined in step S67 that the TA is narrow, the process in step S69 is executed. In step S69, the threshold setting unit 75 determines whether the moving speed of the terminal 21 identified in step S65 is high or low.

If the moving speed is determined to be low in step S69, the process of step S72 is executed. In step S72, the threshold value setting unit 75 calculates the value of the temporary threshold value P by T_RLF×2.

On the other hand, if it is determined in step S69 that the moving speed is high, the process in step S73 is executed. In step S71, the threshold value setting unit 75 calculates the value of the temporary threshold value P by T_RLF×8.

In this way, the temporary threshold P is calculated based on T_RLF, which is the determination time required to determine a wireless link failure. Furthermore, the value of the threshold T_polling is set by multiplying the temporary threshold P calculated in steps S70 to S73 by a predetermined coefficient in subsequent processing.

By determining the size of the TA in step S67 and determining the moving speed of the terminal 21 in steps S68 and S69, it is possible to determine the probability that the terminal 21 will execute the NAS Mobility Update. As described above, when the terminal 21 moves and is connected to a base station corresponding to a cell of a different TA, the terminal 21 executes NAS Mobility Update. Since the CM state of the terminal 21 that has executed the NAS Mobility Update changes to CM-CONNECTED, the CM state can change even without transmitting a polling message.

For example, the terminal 21 that moves at high speed is highly likely to move across TAs and is also likely to execute NAS Mobility Update. Furthermore, if the TA is narrow, the terminal 21 moving at high speed is more likely to move across the TA and more likely to execute NAS Mobility Update. It is inefficient to have such a terminal frequently transmit C-plane messages (polling messages) to 21 in step S38 of FIG. This is because, as described above, the polling message is sent to transition the CM state of the terminal 21. Therefore, in the processes of steps S71 and S73, the value by which the radio link failure determination time T_RLF is multiplied becomes large, and the value of the threshold T_polling also becomes large. Therefore, the threshold time for sending a polling message becomes longer.

On the other hand, for example, a terminal 21 that moves at a low speed is less likely to move across TAs and less likely to execute NAS Mobility Update. Furthermore, when the TA is wide, the terminal 21 moving at low speed is less likely to move across the TA and even less likely to execute NAS Mobility Update. Such a terminal should be made to transmit the C-plane message (polling message) in step S38 in FIG. 6 early. Therefore, in the processes of step S70 and step S72, the value by which the radio link failure determination time T_RLF is multiplied becomes small, and the value of the threshold value T_polling also becomes small. Therefore, the threshold time for sending a polling message becomes shorter.

After the processing in steps S70 to S73, the processing in step S80 in FIG. 8 is executed. In step S80, the threshold setting unit 75 identifies the communication frequency by referring to the behavior acquired in step S63. Here, the communication frequency is specified as information indicating, for example, whether communication is performed regularly at predetermined intervals or communication is performed irregularly. In other words, the communication frequency is information indicating whether or not the terminal 21 executes periodic communication, and can be said to be a characteristic related to periodic communication. Note that communication performed irregularly is also referred to as event-driven communication.

In step S81, the threshold setting unit 75 determines whether the communication frequency specified in step S81 is periodic or event-driven.

If it is determined in step S81 that the communication frequency is event-driven, the process in step S82 is executed. In step S82, the threshold setting unit 75 sets the value of the threshold T_polling to a value (P×α) obtained by multiplying the temporary threshold P by a predetermined coefficient α. The coefficient α may be predetermined as one value, or may be a value determined corresponding to the attribute information acquired in step S61. For example, the value of the coefficient α may be determined depending on the contract between the terminal and the carrier.

If it is determined in step S81 that the communication frequency is periodic, the process in step S83 is executed. In step S83, the threshold value setting unit 75 determines whether the communication interval in periodic communication is smaller than the provisional threshold value P.

If it is determined in step S83 that the communication interval is smaller than the temporary threshold P, the process in step S84 is executed. In step S84, the threshold value setting unit 75 sets the value of the threshold value T_polling to a value obtained by multiplying the temporary threshold value P by 0.9. That is, the value of the threshold T_polling is set so as not to be larger than the communication cycle of the terminal 21. Note that in step S83, the value of the threshold T_polling may be set to the same value as the radio link failure determination time T_RLF.

On the other hand, if it is determined in step S83 that the communication interval is equal to or greater than the temporary threshold P, the threshold setting unit 75 sets the value of the threshold T_polling to the same value as the temporary threshold P.

After the process of step S64 or step S66 in FIG. 7 is executed, the threshold value setting process ends. Further, after the process of step S82, step S84, or step S85 in FIG. 8 is executed, the threshold value setting process ends.

In this way, the threshold value etc. setting process is executed.

(Effects of the first embodiment)
As explained above, the out-of-service area determination control device 70 according to the present embodiment executes the out-of-service area determination process, so that the terminal 21 that is recognized as being on standby by the core network 50 actually becomes out of service area. The location is detected. For example, in the core network 50, the RM state of the terminal 21-3 shown in FIG. It will be determined that there is.

As a result, it is possible to determine whether or not the terminal is located outside the service area without waiting for the expiration of the T3512 timer as in the past, and it is possible to realize a technology that can more quickly determine that the terminal is located outside the service area. . For example, it becomes possible to ascertain whether or not communication with a terminal can be established in a shorter time, which is required for a terminal that is remotely controlled, a terminal that is attached to a moving object, an aircraft, etc.

Further, in the out-of-service area determination control device 70 according to the present embodiment, a threshold value is set for each terminal 21 to determine the timing for transmitting a polling message requesting a response from the terminal 21 to the core network 50. This makes it possible to transmit polling messages at an appropriate transmission frequency depending on the attributes, location, and behavior of the terminal. For example, it is possible to suppress the consumption of wireless communication resources due to unnecessarily increasing the transmission frequency of polling messages, and it is also possible to suppress the power consumption of terminals associated with responses to polling messages.

Furthermore, by using the C-Plane message as the polling message, it is also possible to suppress an increase in communication fees charged to the terminal.

<Second embodiment>
In the first embodiment, when the CM state continues to be CM-IDLE, T=polling, which is the time until a polling message is sent, is set as a threshold for each terminal, and out-of-service determination processing is performed. We have explained an example of executing . However, in addition to T=polling, N_polling, which is the number of times the polling message is transmitted, may be set.

For example, if the reception quality of the signal transmitted from the base station 41 is low in the cell 42 corresponding to the location of the terminal 21, there is a high possibility that the transmission of the polling message or the reception of the response to the polling message will fail. In such a case, it is necessary to ensure that the polling message is retransmitted. For this reason, the threshold value setting unit 75 of the out-of-service area determination control device 70 may further set the number of times N_polling of polling messages is transmitted in addition to the threshold value T=polling.

For example, since the NWDAF 54 analyzes events in each cell, the NWDAF 54 can detect the number of times reconnection occurs in each cell. Since it is considered that the reception quality of the signal transmitted from the base station 41 is low in a cell with a large number of reconnection occurrences, for example, the out-of-service area determination control device 70 determines the reconnection of the cell corresponding to the location of the terminal 21 from the NWDAF 54. All you have to do is get the number of occurrences. Note that information specifying the cell corresponding to the location of the terminal 21 is obtained from the AMF 51, for example.

That is, the threshold setting unit 75 obtains cell information related to cells included in the TA to which the terminal 21 belongs from the core network 50, and sets the number of times of transmission N based on the cell information.

As an example, the threshold setting unit 75 sets N_polling corresponding to the cell at the location of the terminal 21 using a table that associates the number of reconnections with the number of polling message transmissions. It is assumed that a table associating the number of reconnections with the number of polling message transmissions is generated in advance and stored in the storage unit of the out-of-service area determination control device 70, for example. Alternatively, N_polling may be set by performing a predetermined calculation on the number of reconnections.

In this case, the transmission control unit 74 of the out-of-service area determination control device 70 transmits the C-Plane message the number of times corresponding to the value of N_polling at preset intervals (for example, every 10 seconds) in step S38 of FIG. do. For example, when the value of N_polling is 2, the transmission control unit 74 transmits a C-Plane message once, and 10 seconds later transmits a C-Plane message again.

In this way, when N_polling is set, the determination unit 76 of the out-of-service determination control device 70 may determine whether the CM state has transitioned each time a polling message is transmitted. That is, the threshold setting unit 75 further sets the number of times N of polling message transmissions, and the determining unit 76 determines whether the state of the terminal in question has changed in the CM state in the connection management state each time a polling message is transmitted. It may be determined whether or not.

Alternatively, the determining unit 76 may determine whether the CM state has transitioned only once after polling messages have been transmitted the number of times corresponding to the value of N_polling. That is, the threshold setting unit 75 further sets the number of times N of polling messages are transmitted, and the determining unit 76 determines whether or not the state of the terminal has changed in the connection management state after the polling message has been transmitted N times. It may be determined.

In this way, by setting the number of times the polling message is sent for each terminal 21, it becomes possible to send the polling message an optimal number of times depending on the location of the terminal 21. This makes it possible to perform more accurate out-of-range determination while appropriately suppressing the consumption of wireless communication resources and the power consumption of the terminal.

<Third embodiment>
Furthermore, in addition to T=polling, a waiting time from when a polling message is transmitted until it is determined whether or not the terminal 21 is located outside the service area may be set for each terminal. In this case, the waiting time T_wait used in step S39 in FIG. 6 will be set for each terminal.

The terminal 21 may have settings related to DRX (Discontinuous Reception). Information specifying the DRX-related settings of the terminal 21 can be acquired from the control plane function group of the core network 50 as DRX information.

When settings related to DRX are made, the terminal 21 receives signals intermittently. Therefore, compared to the terminal 21 that is not configured for DRX, the terminal 21 that is configured for DRX is likely to take more time to respond to the polling message.

For this reason, the threshold setting unit 75 of the out-of-service determination control device 70 waits for each terminal after sending the polling message until the determination unit 76 executes the process of determining whether or not the CM state of the terminal has transitioned. Further time may be set. Then, the threshold setting unit 75 may obtain DRX information related to DRX (Discontinuous Reception) set in the terminal from the core network 50, and set the standby time based on the DRX information.

As an example, the threshold setting unit 75 sets the waiting time according to the value of DRX cycle included in the DRX information. The threshold setting unit 75 may set T_wait using a table that associates the DRX cycle value with the waiting time, or may set T_wait by performing a predetermined calculation on the DRX cycle value. You may also do so.

Note that the waiting time T_wait may be set only when eDRX (extended DRX) is set in the terminal 21. Whether or not eDRX is configured in the terminal 21 can be determined based on the DRX information. In this case, the value of T_polling may also be set according to the value of eDRX cycle included in the DRX information.

As an example, when eDRX is configured in the terminal 21, the threshold setting unit 75 sets T_polling to M times the eDRX cycle (M is a positive integer), and sets T_wait to the same value as the eDRX cycle. You can do it like this.

By setting the standby time for each terminal 21 in this way, it is possible to appropriately suppress the power consumption of the terminal and to perform a more accurate out-of-service determination.
<Variations regarding threshold, number of transmissions, and waiting time settings>
FIG. 9 is a diagram illustrating variations regarding the settings of the threshold value T_polling, the number of transmissions N_polling, and the waiting time T_wait.

T_polling may be set based on the characteristics of the terminal 21 itself and the characteristics regarding various settings related to communication between the terminal 21 and the base station 41 or the core network.

As an example, the terminal 21 can be classified into a smartphone, a stationary IoT device, or a moving IoT device based on attribute information.

The terminals 21 classified as smartphones are further classified into those used for normal usage, those used while enjoying priority control services, and those used in conjunction with a car or the like. Further, the terminal 21 classified as a stationary IoT device is classified as a CPE (Customer Premises Equipment), a smart meter, or a remote control device. The terminal 21 classified as a moving IoT device is classified as a mobile Wi-Fi (registered trademark) router, a USB dongle, a drone, or a connected vehicle. Furthermore, the terminals 21 classified as drones are classified as drones for within visual line of sight and drones for beyond visual line of sight, and the terminals 21 classified as connected vehicles have automatic driving LV2 or LV3, or automatic driving LV4 or higher. being classified.

For example, since the priority of terminals 21 classified as smartphones, CPEs, mobile Wi-Fi (registered trademark) routers, or USB dongles used in normal usage is considered to be low, T_polling as a relatively long time may be set. On the other hand, for example, since it is considered that a drone for flying beyond visual line of sight or a terminal 21 classified as automatic driving LV4 or higher has a high priority, T_polling as a relatively short time may be set.

Furthermore, the communication capability of the terminal and the available power amount of the terminal are specified from the classification results based on the attribute information, and T_polling, N_polling, or T_wait is set based on the communication capability of the terminal and the available power amount of the terminal. You can do it like this.

The communication capability includes, for example, the strength of radio waves transmitted from the terminal 21, the reception sensitivity of the terminal 21, and the like. For example, the level of communication capability of the terminal 21 may be specified based on the strength of the maximum transmission power, minimum reception sensitivity, etc. of the terminal 21. As an example, the threshold value T_polling of the terminal 21 with low communication ability can be set to a shorter time and the number of transmissions N_polling can also be set to a larger value than the terminal 21 with high communication ability.

Further, the available power amount is, for example, the power amount that the terminal 21 can consume by one charge. For example, the amount of available power of the terminal 21 may be specified based on the battery capacity of the terminal 21, the elapsed time after charging, etc. As an example, the threshold value T_polling of the terminal 21 with a small amount of available power can be set to a long time and the number of transmissions N_polling can also be set to a small value compared to the terminal 21 with a large amount of available power. It is.

Similarly, the terminal 21 can identify the movement speed and communication frequency from the behavior. In the example described above with reference to FIG. 7, it was explained that the moving speed is classified into either low speed or high speed. However, as shown in FIG. 9, when the car moving with the terminal 21 is stuck in a traffic jam, the user holding the terminal 21 is walking, the user holding the terminal 21 is staying indoors, the terminal The user who holds 21 may be classified as traveling by bicycle.

In addition, characteristics related to various settings related to communication between the terminal 21 and the base station 41 or core network include the size of the TA area, settings related to DRX, the value of the T3512 timer, or the ability to reconnect the cell. One example is the abundance.

As described above, the width of the TA can be used, for example, in combination with the movement speed to determine the high possibility that the NAS Mobility Update will be executed. The settings related to DRX can be used, for example, to set the wait time T_wait. The number of cell reconnections can be used, for example, to set the number of polling message transmissions N_polling.

Also, the value of the T3512 timer can be changed by the AMF51. For example, if the time set as the value of the T3512 timer is longer than usual, or if PSM (Power Saving Mode) is used, a process different from the threshold value setting process described in the above embodiment is executed. It is also possible to do so.

The settings of the threshold T_polling, the number of transmissions N_polling, or the waiting time T_wait in the first to third embodiments depend on the characteristics of the terminal 21 itself and the communication between the terminal 21 and the base station 41 or core network. It may be performed in various ways based on the characteristics regarding the various settings.

(Example of implementation using software)
Some or all of the functions of the out-of-service area determination control device 70 may be realized by hardware such as an integrated circuit (IC chip), or may be realized by software.

In the latter case, the out-of-service area determination control device 70 is realized, for example, by a computer that executes instructions of a program that is software that implements each function. An example of such a computer (hereinafter referred to as computer C) is shown in FIG.

Computer C includes at least one processor C1 and at least one memory C2. A program P for operating the computer C as the out-of-service area determination control device 70 is recorded in the memory C2. In the computer C, the processor C1 reads the program P from the memory C2 and executes it, thereby realizing each function of the out-of-service area determination control device 70.

As the processor C1, for example, a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), a DSP (Digital Signal Processor), an MPU (Micro Processing Unit), FPU (Floating point number Processing Unit), PPU (Physics Processing Unit) , a microcontroller, or a combination thereof. As the memory C2, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof can be used.

Note that the computer C may further include a RAM (Random Access Memory) for expanding the program P during execution and temporarily storing various data. Further, the computer C may further include a communication interface for transmitting and receiving data with other devices. Further, the computer C may further include an input/output interface for connecting input/output devices such as a keyboard, a mouse, a display, and a printer.

Furthermore, the program P can be recorded on a non-temporary tangible recording medium M that is readable by the computer C. As such a recording medium M, for example, a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit can be used. Computer C can acquire program P via such recording medium M. Furthermore, the program P can be transmitted via a transmission medium. As such a transmission medium, for example, a communication network or broadcast waves can be used. Computer C can also obtain program P via such a transmission medium.

Further, part or all of the functions of each block of the out-of-service area determination control device 70 can be realized by a logic circuit. For example, an integrated circuit in which logic circuits functioning as each block are formed is also included in the scope of the present invention. In addition to this, it is also possible to realize the functions of each block using, for example, a quantum computer.

In addition, the effects achieved by each aspect of the present invention described above will contribute to the achievement of Goal 9 of the Sustainable Development Goals (SDGs) advocated by the United Nations, "Create a foundation for industry and technological innovation." be.

Furthermore, the present invention is not limited to the embodiments described above, and can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. The embodiments are also included in the technical scope of the present invention.

10 5G network communication system 21 terminal 41 base station 42 cell 50 core network 51 AMF
52 NEF
53 UPF
54 NWDAF
60 Application server 70 Out-of-service determination control device 71 General control unit 72 State confirmation unit 73 Continuation time measurement unit 74 Transmission control unit 75 Threshold value setting unit 76 Determination unit

Claims (16)

An information processing device connected to a core network,
In the registration management state of the terminal managed by the core network, the state of the terminal is a registration state indicating that it is registered with the core network, and in the connection management state of the terminal managed by the core network, If the state of the terminal is an idle state indicating that a connection between the terminal and the control plane function of the core network has not been established, a measurement that measures the duration of the idle state. Department and
a transmission control unit that causes the core network to transmit a polling message requesting a response from the terminal to the core network, when the measured duration exceeds a threshold;
An information processing apparatus, comprising: a threshold setting unit that sets the threshold for each terminal based on information acquired from the core network corresponding to the terminal. The threshold value setting section includes:
acquiring attribute information, which is information related to the purpose, communication capability, or available power amount of the terminal, from the core network;
The information processing device according to claim 1, wherein the threshold value is set based on the attribute information. The threshold value setting section includes:
The information processing device according to claim 2, wherein the communication priority of the terminal within the core network is specified based on the attribute information, and the threshold is set according to the priority. The threshold value setting section includes:
behavior information that is information related to the moving speed and communication frequency of the terminal;
further acquiring location information regarding the location of the terminal from the core network,
The information processing device according to claim 2, wherein the threshold is set based on the attribute information, the behavior information, and the position information. The threshold value setting section includes:
acquiring TA information related to a TA (Tracking Area) to which the terminal belongs from the core network as the location information of the terminal;
The information processing device according to claim 4. The threshold value is
Calculated by multiplying the determination time required to determine a wireless link failure by a predetermined coefficient when the terminal receives a signal transmitted from a base station with reception quality lower than a preset quality value,
The information processing device according to claim 1, wherein the predetermined coefficient is determined based on information acquired from the core network corresponding to the terminal. After a predetermined waiting time has elapsed after sending the polling message, the state of the terminal in the connection management state transitions to a connection state in which a connection between the terminal and a control plane function of the core network is established. The information processing apparatus according to claim 1, further comprising a determination unit that determines that the terminal is located outside the service area if the terminal is not located within the service area. The threshold value setting section includes:
further setting a number N of transmissions of the polling message;
The information processing apparatus according to claim 7, wherein the determination unit determines whether the state of the terminal has changed in the connection management state each time the polling message is transmitted. The threshold value setting section includes:
further setting a number N of transmissions of the polling message;
The information processing apparatus according to claim 7, wherein the determination unit determines whether the state of the terminal has changed in the connection management state after the polling message has been transmitted N times. The threshold value setting section includes:
Obtaining cell information regarding cells included in the TA to which the terminal belongs from the core network;
The information processing device according to claim 8 or 9, wherein the number of times of transmission N is set based on the cell information. The terminal communicates with an application server via the core network,
The information processing device according to claim 7, wherein the core network provides the application server with the determination result of the determination unit. The information processing apparatus according to claim 7, wherein the threshold setting unit further sets the waiting time for each terminal. The threshold value setting section includes:
acquiring DRX information related to DRX (Discontinuous Reception) set in the terminal from the core network;
The information processing device according to claim 12, wherein the standby time is set based on the DRX information. The information processing apparatus according to claim 1, wherein the polling message is a C-Plane message. The C-Plane message is
The information processing device according to claim 14, which is an SMS, NIDD, or PDU session modification command. computer,
An information processing device connected to a core network,
In the registration management state of the terminal managed by the core network, the state of the terminal is a registration state indicating that it is registered with the core network, and in the connection management state of the terminal managed by the core network, If the state of the terminal is an idle state indicating that a connection between the terminal and the control plane function of the core network has not been established, a measurement that measures the duration of the idle state. Department and
a transmission control unit that causes the core network to transmit a polling message requesting a response from the terminal to the core network, when the measured duration exceeds a threshold;
A program for functioning as an information processing apparatus, comprising: a threshold value setting unit that sets the threshold value for each terminal based on information acquired from the core network corresponding to the terminal.

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