WO2022080001A1 - Base station and wireless system - Google Patents

Abstract

A base station comprises: a wireless communication unit that wirelessly communicates with terminals; and a transmission processing unit for causing, in response to reception by the wireless communication unit of a tracking area update request from a first terminal, the wireless communication unit to transmit information for completing the tracking area update processing of the first terminal to the first terminal, causing the wireless communication unit to transmit information for specifying a second terminal different from the first terminal to the first terminal, and causing the first terminal to transmit information for completing the tracking area update processing of the second terminal to the second terminal.

Description

Base station and wireless system

This disclosure relates to base stations and wireless systems. The present application claims priority to Japanese Patent Application No. 2020-172422 filed in Japan on October 13, 2020, the contents of which are incorporated herein by reference.

Patent Document 1 discloses a wireless communication network. The base station constituting the wireless communication network acquires information on the moving direction of each wireless communication terminal from the signal obtained by wireless communication with each wireless communication terminal constituting the wireless communication network. Further, the base station manages a plurality of wireless communication terminals having the same moving direction as a group. Further, when the communication state with a plurality of wireless communication terminals belonging to the group deteriorates, the base station issues a handover instruction to the plurality of wireless communication terminals. When issuing a handover instruction, the base station determines a target base station for the plurality of wireless communication terminals. Further, the base station transmits information for identifying the target base station to the plurality of wireless communication terminals.

Japanese Patent No. 5399860

In the wireless communication network disclosed in Patent Document 1, the base station must give a handover instruction to all of the plurality of wireless communication terminals belonging to the group. Therefore, when the number of the plurality of wireless communication terminals is large, a large load is applied to the base station. For this reason, there are problems such as a long time required for the plurality of wireless communication terminals to perform the handover, and a wireless communication terminal in which the wireless communication is disconnected is generated.

This disclosure was made in view of these issues. It is an object of the present disclosure to reduce the processing performed by a base station that wirelessly communicates with many terminals.

A base station of one embodiment of the present disclosure has a wireless communication unit that wirelessly communicates with a terminal, and in response to the wireless communication unit receiving a tracking area update request from a first terminal, the wireless communication unit is notified of the wireless communication unit. Information for completing the tracking area update process of the first terminal is transmitted to the first terminal, and the wireless communication unit is provided with information for identifying a second terminal different from the first terminal. The first terminal is provided with a transmission processing unit for transmitting information for completing the tracking area update process of the second terminal to the second terminal.

Further, another form of the wireless communication system of the present disclosure includes the base station of the present disclosure, the first terminal, and the second terminal.

According to the present disclosure, the tracking area update process of the first terminal and the second terminal without the base station transmitting the information for completing the tracking area update process of the second terminal to the second terminal. Can be completed. Therefore, the processing performed by the base station can be reduced.

It is a figure which schematically illustrates the mobile communication network of 1st Embodiment. It is a figure explaining the tracking area update process performed in the mobile communication network of 1st Embodiment. It is a figure explaining the tracking area update process performed in the mobile communication network of 1st Embodiment. It is a figure which schematically illustrates the composition example of the group in the mobile communication network of 1st Embodiment. It is a block diagram which schematically illustrates the base station provided in the mobile communication network of 1st Embodiment. It is a block diagram which shows typically the terminal provided in the mobile communication network of 1st Embodiment. It is a figure explaining the connection state of the base station and the terminal provided in the mobile communication network of 1st Embodiment. It is a flowchart which shows the flow of the tracking area update process by grouping performed in the mobile communication network of 1st Embodiment. It is a flowchart which shows the flow of the tracking area update process by grouping performed in the mobile communication network of 1st Embodiment. The state in which a plurality of terminals belonging to a group are inside one vehicle provided in the mobile communication network of the first embodiment is schematically illustrated. The state in which a plurality of terminals belonging to a group are inside one vehicle provided in the mobile communication network of the second embodiment is schematically illustrated. It is a flowchart which shows the flow of the tracking area update process by grouping performed in the mobile communication network of 2nd Embodiment. It is a flowchart which shows the flow of the tracking area update process by grouping performed in the mobile communication network of 2nd Embodiment.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicate description will be omitted.

1 First Embodiment 1.1 Mobile Communication Network FIG. 1 is a diagram schematically showing the mobile communication network 1 of the first embodiment.

As illustrated in FIG. 1, the mobile communication network 1 includes a core network 11 and a plurality of terminals 12. The core network 11 includes a plurality of base stations 21.

The plurality of terminals 12 and the plurality of base stations 21 constitute a wireless system. Each terminal 12 included in the plurality of terminals 12 can wirelessly communicate with one base station 21 selected from the plurality of base stations 21. The base station 21 with which each terminal 12 wirelessly communicates can be switched. The plurality of base stations 21 can communicate with each other.

1.2 Tracking Area Update Process FIGS. 2 and 3 are schematic views illustrating a tracking area update process performed in the mobile communication network 1 of the first embodiment.

FIG. 2 illustrates the first base station 21P and the second base station 21Q included in the plurality of base stations 21. Further, FIG. 2 shows a plurality of connected terminals 12C included in the plurality of terminals 12. Further, FIG. 2 shows a train 32 having a plurality of vehicles 31.

In the situation illustrated in FIG. 2, the plurality of connected terminals 12C are inside the cell of the first base station 21P and are connected to the first base station 21P. The plurality of connected terminals 12C are terminals owned by passengers on the train 32, and are moving from the inside of the cell of the first base station 21P to the inside of the cell of the second base station 21Q together with the train 32. ..

In the situation illustrated in FIG. 2, the cell switching process of the plurality of connected terminals 12C for switching the base station to which the plurality of connected terminals 12C are connected from the first base station 21P to the second base station 21Q is performed. Must be done.

The plurality of connected terminals 12C include an idle terminal 12I and an active terminal 12A. The idle terminal 12I does not wirelessly communicate with the first base station 21P. The active terminal 12A wirelessly communicates with the first base station 21P.

When the cell switching process of the idle terminal 12I is performed, the tracking area update process of the idle terminal 12 is performed. When the tracking area update process of the idle terminal 12I is performed, the idle terminal 12I randomly accesses the first base station 21P and transmits a tracking area update request to the first base station 21P. Further, the base station identifier (base station ID) that identifies the base station to which the idle terminal 12I is connected is updated from the base station ID of the first base station 21P to the base station ID of the second base station 21Q. When the cell switching process of the active terminal 12A is performed, the handover process of the active terminal 12A is performed.

The plurality of connected terminals 12C often include a large number of idle terminals 12I and a small number of active terminals 12A.

Therefore, in the situation shown in FIG. 2, the tracking area update process of a large number of idle terminals 12I is performed when the tracking area update is triggered. Therefore, when the tracking area is updated, a large number of idle terminals 12I randomly access the first base station 21P all at once. Therefore, a large load is applied to the first base station 21P.

Therefore, in the first embodiment, as shown in FIG. 3, a plurality of terminals 12 are grouped. Further, one terminal 12 included in the plurality of terminals 12 belonging to the group 41 is the reader terminal 12L. Further, the remaining terminals 12 included in the plurality of terminals 12 are member terminals 12M. Further, the first base station 21P undertakes the tracking area update process of the reader terminal 12L, and performs the tracking area update process of the reader terminal 12L in cooperation with the reader terminal 12L. Further, the reader terminal 12L undertakes the tracking area update process of the member terminal 12M, and performs the tracking area update process of the member terminal 12M in cooperation with the member terminal 12M. The first base station 21P wirelessly communicates with the reader terminal 12L when performing the tracking area update process of the reader terminal 12L, and instructs the reader terminal 12L to update the base station ID by wireless communication. When the tracking area update process of the member terminal 12M is performed, the reader terminal 12L performs wireless communication between the member terminals 12M and instructs the member terminal 12M to update the base station ID by the wireless communication between the terminals. As a result, the reader terminal 12L and the member terminal 12M are connected to the base station identified by the updated base station ID, and can wirelessly communicate with the base station. As a result, the first base station 21P needs to undertake the tracking area update process of the reader terminal 12L, but does not need to undertake the tracking area update process of the member terminal 12M. Therefore, it is possible to prevent a large load from being applied to the first base station 21P.

The plurality of terminals 12 do not have to be terminals owned by passengers on the train 32. For example, the plurality of terminals 12 may be terminals owned by passengers on a plurality of sightseeing buses traveling in tandem. When the terminal owned by a specific person is the reader terminal 12L, the plurality of terminals 12 may be terminals owned by a group traveler who is walking inside a station, an airport, etc., or a station, a bus stop, etc. It may be a terminal owned by an spectator who is walking from to a large-scale venue such as an exhibition hall, a concert hall, or a stadium. The plurality of terminals 12 may be terminals owned by a group moving in a limited range. For example, the plurality of terminals 12 may be terminals owned by employees moving inside the office, terminals owned by students moving inside the school, or one of condominiums and the like. It may be a terminal owned by a resident who is moving inside the house. A situation in which a large number of employees are moving inside the office occurs, for example, when all employees are moving to the hall or when all employees are participating in an evacuation drill.

1.3 Method of grouping When a plurality of terminals 12 are terminals owned by passengers on the train 32, the plurality of terminals 12 are gathered and move greatly. On the other hand, in the case where the plurality of terminals 12 are terminals owned by an audience who walks to a large-scale venue, the plurality of terminals 12 gather but do not move significantly.

When a plurality of terminals 12 move significantly, a plurality of terminals 12 having a common attribute may be grouped, or a plurality of terminals 12 having location information satisfying a specific condition may be grouped.

The plurality of terminals 12 having a common attribute are terminals having the same operator, terminals having a common identifier (ID), terminals using the same band, and the like.

The plurality of terminals 12 having position information satisfying a specific condition are terminals possessed by passengers on the same vehicle 31, terminals moving in the same direction, and the like, which are determined from the position information of the plurality of terminals 12. ..

Even when the plurality of terminals 12 do not move significantly, a plurality of terminals 12 having a common attribute may be grouped, or a plurality of terminals 12 having location information satisfying a specific condition may be grouped.

The plurality of terminals 12 having a common attribute are terminals having the same operator, terminals having a common identifier (ID), terminals using the same band, and the like.

The plurality of terminals 12 having position information satisfying a specific condition are terminals and the like existing in a specific area included in the plurality of areas, which are determined from the position information of the plurality of terminals 12. Multiple areas are set by dividing the area. In this case, by mounting the reader terminal 12L on the drone, it is possible to set a plurality of areas without being bound by the position. A plurality of areas may be set only when a plurality of terminals 12 are expected to be accumulated, such as when an event is held.

1.4 Method for determining reader terminal A plurality of terminals 12 belonging to one group 41 search for and access a base station 21. In the first embodiment, the base station 21 sets the reader terminal 12L as the terminal 12 that first accesses the base station 21 among the plurality of terminals 12. When the plurality of terminals 12 are terminals existing inside the same vehicle 31, the terminal 12 that first accesses the base station 21 among the plurality of terminals 12 existing inside the same vehicle 31 becomes the reader terminal 12L. Set. As a result, the terminal 12 inside the vehicle 31 can be a candidate for the reader terminal 12L.

The order in which the plurality of terminals 12 belonging to one group 41 access the base station 21 may be ignored, and any terminal 12 selected from the plurality of terminals 12 may be set as the reader terminal 12L. The terminal 12 fixedly installed inside the vehicle 31 may be set to the reader terminal 12L. In this case, the terminal 12 newly entered inside the vehicle 31 negotiates with the reader terminal 12L to become the member terminal 12M. A specific example thereof will be described in the second embodiment.

1.5 Group management method The base station 21 manages the group 41. When managing the group 41, the base station 21 uses a group identifier (group ID) that identifies the group 41. The management of the group 41 includes processing such as creation of the group 41, registration of the terminal 12 in the group 41, withdrawal of the terminal 12 from the group 41, and release of the group 41.

The base station 21 associates a member terminal list including information identifying a plurality of terminals 12 belonging to the group 41 with a group ID that identifies the group 41.

When the terminal 12 is registered in the group 41, the information for identifying the terminal 12 is added to the member terminal list associated with the group ID that identifies the group 41. As a result, the terminal 12 belongs to the group 41.

When the terminal 12 is withdrawn from the group 41, the information identifying the terminal 12 is deleted from the member terminal list associated with the group ID that identifies the group 41. As a result, the terminal 12 does not belong to the group 41.

The base station 21 manages the group ID, notifies the leader terminal 12L belonging to the group 41 identified by the group ID of the group ID, and also notifies the member terminal 12M belonging to the group 41 via the reader terminal 12L. do.

The reader terminal 12L collaborates with the member terminal 12M belonging to the group 41 to which the reader terminal 12L belongs to perform the tracking area update process of the member terminal 12M.

When a large number of terminals 12 exist, a plurality of groups 41 may be created. In this case, the large number of terminals 12 are divided into a plurality of groups 41. Further, a reader terminal 12L belonging to each group 41 included in the plurality of groups 41 may be set, and as a result, a plurality of reader terminals 12L may be set. When a plurality of reader terminals 12L are set, the member terminal 12M belonging to the group 41 to which the upper level reader terminal 12L belongs may be set as the lower level reader terminal 12L. As a result, a tree-shaped terminal network having the top-level reader terminal 12L as the apex is formed, and a plurality of groups 41 can be managed.

When the plurality of terminals 12 belonging to the group 41 are terminals owned by passengers on the vehicle 31, the terminals 12 owned by the passengers who got off the vehicle 31 when the vehicle 31 stopped at the station are separated from the group 41. Will be. Further, the terminal 12 owned by the passenger who newly got on the vehicle 31 when the vehicle 31 stops at the station is registered in the group 41. Therefore, the member terminal list must be updated when the vehicle 31 stops at the station.

1.6 Group Configuration Example FIG. 4 is a diagram schematically illustrating a configuration example of the group 41 in the mobile communication network 1 of the first embodiment.

As shown in FIG. 4, a plurality of groups 41 may be configured in the mobile communication network 1. In the configuration example shown in FIG. 4, the plurality of groups 41 are three groups. A reader terminal 12L and a member terminal 12M belong to each group 41.

1.7 Base station FIG. 5 is a block diagram schematically showing a base station 21 provided in the mobile communication network 1 of the first embodiment.

As shown in FIG. 5, the base station 21 includes a wireless communication unit 51, a connection unit 52, a control unit 53, and a storage unit 54.

The wireless communication unit 51 is connected to the terminal 12 and communicates with the connected terminal 12.

The connection unit 52 is connected to the core network 11 and communicates with the core network 11. Information transmission performed between the base stations 21 when the tracking area update is performed is performed via the core network 11.

The control unit 53 controls the operation of the base station 21.

The storage unit 54 stores data. The stored data includes transmission / reception data, control data, and the like.

As shown in FIG. 5, the base station 21 includes a grouping unit 61, a selection unit 62, and a transmission processing unit 63. The grouping unit 61, the selection unit 62, and the transmission processing unit 63 are provided in the control unit 53.

The grouping unit 61 groups a plurality of terminals 12. The grouping unit 61 groups a plurality of terminals 12 according to the grouping method described above.

The selection unit 62 selects the reader terminal 12L from a plurality of terminals 12 belonging to the group 41. As a result, the plurality of terminals 12 include a first terminal that becomes the reader terminal 12L and a second terminal that becomes the member terminal 12M. The member terminal 12M is a terminal different from the reader terminal 12L, and is a terminal other than the reader terminal 12L. In the first embodiment, the selection unit 62 makes the reader terminal 12L the terminal 12 to which the wireless communication unit 51 first receives the tracking area update request among the plurality of terminals 12.

In response to the wireless communication unit 51 receiving the tracking area update request from the reader terminal 12L, the transmission processing unit 63 causes the wireless communication unit 51 to read information for completing the tracking area update process of the reader terminal 12L. Send to the terminal 12L. Further, the transmission processing unit 63 causes the wireless communication unit 51 to transmit information identifying the member terminal 12M to the reader terminal 12L in response to the wireless communication unit 51 receiving the tracking area update request from the reader terminal 12L. .. As a result, the reader terminal 12L can transmit information for completing the tracking area update process of the member terminal 12M to the member terminal 12M.

The transmission processing unit 63 causes the connection unit 52 to transmit a member terminal list including information specifying a plurality of terminals 12 belonging to the group 41 to the core network 11. The transmitted information is notified to the base station 21 with which the plurality of terminals 12 will wirelessly communicate when the tracking update process of the plurality of terminals 12 is performed.

Further, when the connection unit 52 receives a member terminal list including information specifying a plurality of terminals 12 belonging to the group 41 from the core network 11, the selection unit 62 selects the reader terminal 12L from the plurality of terminals 12. .. The received member terminal list is notified from the base station 21 with which the plurality of terminals 12 have been wirelessly communicating when the tracking update process of the plurality of terminals 12 is performed.

The reader terminal 12L and the member terminal 12M that are the targets of the tracking area update process are connected terminals that are connected to the base station 21 but do not perform wireless communication, that is, idle terminals 12I.

The member terminal list is stored in the storage unit 54.

1.8 Terminal FIG. 6 is a block diagram schematically showing a terminal 12 provided in the mobile communication network 1 of the first embodiment.

The terminal 12 is, for example, a feature phone, a smartphone, a tablet, or the like. As shown in FIG. 6, the terminal 12 includes a first wireless communication unit 71, a second wireless communication unit 72, a control unit 73, and a storage unit 74.

The first wireless communication unit 71 is connected to the base station 21 and wirelessly communicates with the connected base station 21.

The second wireless communication unit 72 is connected to another terminal 12 and wirelessly communicates with the connected other terminal 12. For example, the second wireless communication unit 72 of the reader terminal 12L is connected to the member terminal 12M and wirelessly communicates with the connected member terminal 12M. Further, the second wireless communication unit 72 of the member terminal 12M is connected to the reader terminal 12L, wirelessly communicates with the connected reader terminal 12L, is connected to the other member terminal 12M, and is connected to the other member terminal 12M. Wirelessly communicate with.

The control unit 73 controls the operation of the terminal 12.

The storage unit 74 stores data. The stored data includes transmission / reception data, control data, and the like.

When the terminal 12 is the reader terminal 12L, the control unit 73 responds to the first wireless communication unit 71 receiving information from the base station 21 for completing the tracking area update process of the terminal 12. The tracking area update process of the terminal 12 is performed. Further, the control unit 73 responds to the first wireless communication unit 71 receiving a member terminal list including information identifying a plurality of terminals 12 belonging to the group 41 from the base station 21, and the second wireless communication unit 73. The unit 72 is made to transmit the information for completing the tracking area update process of the member terminal 12M to the member terminal 12M. The member terminal 12M performs the tracking area update process of the member terminal 12M in response to the second wireless communication unit 72 receiving information for completing the tracking area update process of the member terminal 12M from the reader terminal 12L. ..

1.9 Connection state of base station and terminal FIG. 7 is a diagram illustrating a connection state of base station 21 and terminal 12 provided in the mobile communication network 1 of the first embodiment.

(A) During communication As shown in FIG. 7, during communication, the base station 21 and the terminal 12 are connected to each other and exchange data. At that time, the terminal 12 uses the first wireless communication unit 71 for communication. This point is the same regardless of whether the terminal 12 is a reader terminal 12L or a member terminal 12M. During communication, the reader terminal 12L and the member terminal 12M do not need to cooperate with each other, so that the reader terminal 12L and the member terminal 12M do not need to be connected to each other.

(B) At the time of selection As shown in FIG. 7, at the time of selection, the base station 21 and the reader terminal 12L are connected to each other and perform a tracking area update process. At that time, the reader terminal 12L uses the first wireless communication unit 71 for communication. Further, the reader terminal 12L and the member terminal 12M are connected to each other and perform a tracking area update process. At that time, the reader terminal 12L and the member terminal 12M use the second wireless communication unit 72 for communication. When at least one of the reader terminal 12L and the member terminal 12M does not have the second wireless communication unit 72, the reader terminal 12L and the member terminal 12M may use the first wireless communication unit 71 for communication. When the tracking area update process is performed, the base station 21 connected to the plurality of terminals 12 belonging to the group 41 has a base station ID that identifies the base station 21 and information that identifies the plurality of terminals 12. The member terminal list including the above is transmitted to the base station 21 to which the plurality of terminals 12 are connected next.

(C) Others (when idle, etc.)
As shown in FIG. 7, in other states such as idle, the base station 21 and the terminal 12L are connected to each other and maintain synchronization. Similarly, the terminals 12L and 12M are also connected to each other and maintain synchronization.

1.10 Flow of tracking area update process by grouping FIGS. 8 and 9 are flowcharts showing a flow of tracking area update process by grouping performed in the mobile communication network 1 of the first embodiment. 8 and 9 show a flow of processing performed by the first base station 21P, the second base station 21Q, the reader terminal 12L, and the member terminal 12M.

In step S101, the grouping unit 61 of the first base station 21P groups a plurality of terminals 12 to which the tracking area update process is performed collectively, and assigns a group ID for identifying the group 41 to which the plurality of terminals 12 belong. Determine and create a member terminal list containing information identifying the plurality of terminals 12. However, a plurality of terminals 12 that have already been grouped have moved from the previous base station to the first base station 21P by the tracking area update process, and the first base station 21P has the group ID and the group ID from the previous base station. When receiving the member terminal list, the first base station 21P inherits the received group ID and the member terminal list, and does not execute step S101.

In step S102, a plurality of terminals 12 belonging to the group 41 move.

In step S103, since the plurality of terminals 12 belonging to the group 41 have moved, the tracking area update (TAU) process of the plurality of terminals 12 must be performed. Therefore, the tracking area update request of the plurality of terminals 12 is generated.

In step S104, the control unit 73 of each terminal 12 included in the plurality of terminals 12 belonging to the group 41 sends a tracking area update request to the first wireless communication unit 71 of each terminal 12 to the first base station 21P. To send to. The transmission of the tracking area update request from the plurality of terminals 12 to the first base station 21P is performed at random.

In step S105, the wireless communication unit 51 of the first base station 21P receives the tracking area update request from the first terminal 12 among the plurality of terminals 12 belonging to the group 41.

In step S106, the transmission processing unit 63 of the first base station 21P causes the wireless communication unit 51 of the first base station 21P to provide information for completing the tracking area update process of the first terminal 12 to the first terminal. Send to 12. The information includes a base station ID that identifies a second base station 21Q to which a plurality of terminals 12 belonging to the group 41 are next connected.

In step S107, the first wireless communication unit 71 of the first terminal 12 receives information from the first base station 21P for completing the tracking area update process of the first terminal 12. The information includes a base station ID that identifies a second base station 21Q to which a plurality of terminals 12 belonging to the group 41 are next connected.

In step S108, the selection unit 62 of the first base station 21P selects the first terminal 12 from the plurality of terminals 12 belonging to the group 41. Further, the transmission processing unit 63 of the first base station 21P causes the wireless communication unit 51 of the first base station 21P to transmit information for making the first terminal 12 into the reader terminal 12L to the first terminal 12.

In step S109, the control unit 73 of the first terminal 12 receives information from the first base station 21P for the first wireless communication unit 71 of the first terminal 12 to make the first terminal 12 a reader terminal 12L. In response to this, the process for the first terminal 12 to become the reader terminal 12L is completed.

In step S110, even if the first base station 21P receives a tracking area update request from a terminal 12 other than the first terminal 12, the tracking area update request is ignored and the tracking area is concerned. Does not respond to update requests.

In step S111, the transmission processing unit 63 of the first base station 21P provides the wireless communication unit 51 of the first base station 21P with a member terminal list including information specifying a plurality of member terminals 12M belonging to the group 41. Send to the reader terminal 12L.

In step S112, the first wireless communication unit 71 of the reader terminal 12L receives a member terminal list including information identifying a plurality of member terminals 12M belonging to the group 41 from the first base station 21P.

In step S113, the control unit 73 of the reader terminal 12L updates the base station information indicating the base station to which the reader terminal 12L is connected from the first base station 21P to the second base station 21Q. As a result, in response to the first wireless communication unit 71 of the first terminal 12 receiving information for completing the tracking area update process of the first terminal 12 from the first base station 21P, the reader terminal 12L Tracking area update process is completed.

In step S114, the control unit 73 of the reader terminal 12L causes the second wireless communication unit 72 of the reader terminal 12L to transmit information for completing the tracking area update process of the member terminal 12M to the member terminal 12M. The information includes a base station ID that identifies a second base station 21Q to which a plurality of terminals 12 belonging to the group 41 are next connected.

In step S115, the second wireless communication unit 72 of the member terminal 12M receives information from the reader terminal 12L for completing the tracking area update process of the member terminal 12M. The information includes a base station ID that identifies a second base station 21Q to which a plurality of terminals 12 belonging to the group 41 are next connected.

In steps S114 and S115, the base station ID that identifies the second base station 21Q is notified from the reader terminal 12L to the member terminal 12M by wireless communication between terminals. Therefore, the member terminal 12M does not need to communicate with the first base station 21P in order to obtain the base station ID that identifies the second base station 21Q. The base station ID may be notified by communication that does not go through the base station other than wireless communication between terminals. For example, the base station ID may be notified by multicast-type D2D communication.

In step S116, the control unit 73 of the member terminal 12M updates the base station information indicating the base station to which the member terminal 12M is connected from the first base station 21P to the second base station 21Q. As a result, in response to the second wireless communication unit 72 of the member terminal 12M receiving information for completing the tracking area update process of the member terminal 12M from the reader terminal 12L, the tracking area update process of the member terminal 12M is performed. Is completed.

In step S117, the control unit 73 of the member terminal 12M notifies the second wireless communication unit 72 of the member terminal 12M that the tracking area update of the member terminal 12M is completed. To send to.

In step S118, the second wireless communication unit 72 of the reader terminal 12L receives the tracking area update completion notification from all of the member terminals 12M.

In step S119, the control unit 73 of the reader terminal 12L notifies the first wireless communication unit 71 of the reader terminal 12L that all tracking area update processing of the plurality of terminals 12 belonging to the group 41 is completed. The area update completion notification is transmitted to the second base station 21Q.

In step S120, the wireless communication unit 51 of the second base station 21Q notifies from the reader terminal 12L that all tracking area updates of the plurality of terminals 12 belonging to the group 41 have been completed. Receive.

In the tracking area update process by grouping, steps S121 to S123 are executed separately from steps S111 to S120.

In step S121, the transmission processing unit 63 of the first base station 21P sets a member terminal list including information for identifying a plurality of terminals 12 belonging to the group 41 in the connection unit 52 of the first base station 21P in the core network. Send to 11. The first base station 21P may delete the transmitted member terminal list after the member terminal list is transmitted to the core network 11.

In step S122, the connection unit 52 of the second base station 21Q receives a member terminal list including information identifying a plurality of terminals 12 belonging to the group 41 from the core network 11.

In step S123, the control unit 53 of the second base station 21Q updates the managed member terminal list based on the received member terminal list.

After the first base station 21P updates all the base station information of the plurality of terminals 12 belonging to the group 41, the first base station 21P gives the information about the plurality of terminals 12 to the second base station together with the group ID for identifying the group 41. It may be transmitted to 21Q. The information about the plurality of terminals 12 is a terminal ID that identifies the plurality of terminals 12, location information of the plurality of terminals 12, and the like.

According to the tracking area update process by this grouping, the first base station 21P does not send the information for completing the tracking area update process of the member terminal 12M to the member terminal 12M, but the reader terminal 12L and the member terminal. The 12M tracking area update process can be completed. Therefore, the processing performed by the first base station 21P can be reduced. That is, in conjunction with a tracking area update request from any one terminal 12 included in the plurality of terminals 12 belonging to the group 41, all of the plurality of terminals 12 receive base station information indicating a base station to be connected. It is possible to update from the first base station 21P to the second base station 21Q.

2 Second Embodiment The second embodiment is different from the first embodiment in the following points. Regarding points not described below, the same configuration as that adopted in the first embodiment is adopted in the second embodiment.

10 and 11 are diagrams illustrating the differences between the first embodiment and the second embodiment. FIG. 10 schematically illustrates a state in which a plurality of terminals 12 belonging to the group 41 provided in the mobile communication network 1 of the first embodiment are inside one vehicle 31. FIG. 11 schematically illustrates a state in which a plurality of terminals 12 belonging to the group 41 provided in the mobile communication network 1 of the second embodiment are inside one vehicle 31.

In the first embodiment, as shown in FIG. 10, any terminal included in the plurality of terminals 12 belonging to the group 41 can be the reader terminal 12L. For example, the terminal that first transmits the tracking area update process to the base station 21 is the reader terminal 12L.

On the other hand, in the second embodiment, as shown in FIG. 11, the specific terminal 12 included in the plurality of terminals 12 belonging to the group 41 is the reader terminal 12L. The reader terminal 12L is fixedly installed on the vehicle 31, for example. The shape, configuration, function, etc. of the reader terminal 12L are not limited. The model of the reader terminal 12L may be the same as the model of the member terminal 12M, or may be different from the model of the member terminal 12M. When the model of the reader terminal 12L is different from the model of the member terminal 12M, for example, the model of the reader terminal 12L may be a model having a function of being a master unit, and the model of the member terminal 12M is a child. It may be a model having a function as a machine. In response to receiving the tracking area update request from the member terminal 12M, the reader terminal 12L transmits information for completing the tracking area update process of the member terminal 12M to the member terminal 12M.

When the reader terminal 12L is a specific terminal and is fixedly installed on the vehicle 31, the reader terminal 12L is determined. Therefore, the reader terminal 12L uses the terminal 12 that entered the vehicle 31 after the reader terminal 12L is installed. It has the advantage of being recognizable.

Taking advantage of this, when the terminal 12 goes out of the cell of the reader terminal 12L, the reader terminal 12L deletes the terminal 12 from the member terminal 12M belonging to the group 41 to which the reader terminal 12L belongs, and that is noted. Notify the base station 21. When the terminal 12 enters the cell of the reader terminal 12L, the reader terminal 12L receives the tracking area update request made by the terminal 12 and adds the terminal 12 to the member terminal 12M belonging to the group 41 to which the reader terminal 12L belongs. Then, the base station 21 is notified of this. When the terminal 12 moves from one vehicle 31 to another vehicle 31 inside the train 32, the leader terminal 12L inside the one vehicle 31 is from the member terminal 12M belonging to the group 41 to which the leader terminal 12L belongs. The terminal 12 is deleted, and the base station 21 is notified of this. The reader terminal 12L inside the other vehicle 31 receives the tracking area update request made by the terminal 12 and adds the terminal 12 to the member terminal 12M belonging to the group 41 to which the reader terminal 12L belongs, and bases it on this. Notify station 21. As a result, the member terminal list is updated by the reader terminal 12L.

If the tracking area update of the terminal 12 is completed before the update of the member terminal list by the reader terminal 12L, only the member terminal list is updated by the base station 21. Therefore, the member terminal list managed by the base station 21 and the member terminal list managed by the reader terminal 12L are different from each other. In order to avoid this problem, the reader terminal 12L periodically refers to the member terminal list managed by the base station 21, and the member terminal list managed by the base station 21 and the member terminal managed by the reader terminal 12L. Synchronize with the list with each other.

12 and 13 are flowcharts showing the flow of the tracking area update process by grouping performed in the mobile communication network 1 of the second embodiment. 12 and 13 show a flow of processing performed by the first base station 21P, the second base station 21Q, the reader terminal 12L, and the member terminal 12M.

In step S201, the grouping unit 61 of the first base station 21P groups a plurality of terminals 12 to which the tracking area update process is performed collectively, and assigns a group ID for identifying the group 41 to which the plurality of terminals 12 belong. Determine and create a member terminal list containing information identifying the plurality of terminals 12. However, a plurality of terminals 12 that have already been grouped have moved from the previous base station to the first base station 21P by the tracking area update, and the first base station 21P has the group ID and members from the previous base station. When receiving the terminal list, the first base station 21P inherits the received group ID and member terminal list, and does not execute step S201.

In step S202, a plurality of terminals 12 belonging to the group 41 move.

In step S203, since the plurality of terminals 12 belonging to the group 41 have moved, the tracking area update process of the plurality of terminals 12 must be performed. Therefore, the tracking area update request of the plurality of terminals 12 is generated.

In step S204, the control unit 73 of each terminal 12 included in the plurality of terminals 12 belonging to the group 41 causes the second wireless communication unit 72 of each terminal 12 to transmit the tracking area update request to the reader terminal 12L. .. The tracking area update request is randomly transmitted from the plurality of terminals 12 to the reader terminal 12L.

In step S205, the second wireless communication unit 72 of the reader terminal 12L receives the tracking area update request from the terminal 12.

In step S206, the control unit 73 of the reader terminal 12L registers the terminal 12 that has transmitted the tracking area update request in the group 41. As a result, the terminal 12 becomes a member terminal 12M. However, if the terminal 12 that has sent the tracking area update request is already registered in the group 41 and becomes a member terminal 12M, the reader terminal 12L may ignore the tracking area update request.

In step S207, the control unit 73 of the reader terminal 12L causes the first wireless communication unit 71 of the reader terminal 12L to transmit the tracking area update request to the first base station 21P.

In step S208, the wireless communication unit 51 of the first base station 21P receives the tracking area update request from the reader terminal 12L.

In step S209, the transmission processing unit 63 of the first base station 21P sends information to the wireless communication unit 51 of the first base station 21P to the reader terminal 12L to complete the tracking area update process of the reader terminal 12L. Send it. The information includes a base station ID that identifies a second base station 21Q to which a plurality of terminals 12 belonging to the group 41 are next connected.

In step S210, the first wireless communication unit 71 of the reader terminal 12L receives information from the first base station 21P for completing the tracking area update process of the reader terminal 12L. The information includes a base station ID that identifies a second base station 21Q to which a plurality of terminals 12 belonging to the group 41 are next connected.

In the following steps S211 to S223, the same processing as that performed in steps S111 to S123 of the first embodiment is performed.

Also in the second embodiment, as in the first embodiment, the first base station 21P does not transmit the information for completing the tracking area update process of the member terminal 12M to the member terminal 12M, but the reader terminal 12L. And the tracking area update process of the member terminal 12M can be completed. Therefore, the processing performed by the first base station 21P can be reduced.

The present disclosure is not limited to the above-described embodiment, and is substantially the same as the configuration shown in the above-described embodiment, a configuration having the same action and effect, or a configuration capable of achieving the same purpose. May be replaced with.

Claims (10)

1. The wireless communication unit that wirelessly communicates with the terminal,
   In response to the wireless communication unit receiving the tracking area update request from the first terminal, the wireless communication unit is provided with information for completing the tracking area update process of the first terminal. The wireless communication unit is made to transmit to the terminal, and the information for identifying the second terminal different from the first terminal is transmitted to the first terminal, and the first terminal is made to transmit the information of the second terminal. A transmission processing unit that transmits information for completing the tracking area update process to the second terminal, and a transmission processing unit.
   Base station equipped with.
2. A grouping unit that groups multiple terminals,
   A selection unit that selects the first terminal from the plurality of terminals,
   Equipped with
   The base station according to claim 1, wherein the second terminal is a terminal other than the first terminal included in the plurality of terminals.
3. The base station according to claim 2, wherein the plurality of terminals have common attributes.
4. The base station according to claim 2 or 3, wherein the plurality of terminals have location information satisfying a specific condition.
5. Connections that communicate with the core network and
   A selection unit that selects the first terminal from the plurality of terminals when the connection unit receives information for identifying a plurality of terminals from the core network.
   Equipped with
   The base station according to any one of claims 1 to 4, wherein the second terminal is a terminal other than the first terminal included in the plurality of terminals.
6. The base station according to any one of claims 2 to 5, wherein the selection unit uses the terminal for which the wireless communication unit first receives the tracking area update request as the first terminal among the plurality of terminals.
7. Equipped with a connection to communicate with the core network
   The base station according to any one of claims 2 to 6, wherein the transmission processing unit causes the connection unit to transmit information identifying the plurality of terminals to the core network.
8. The first terminal is a specific terminal, and in response to receiving a tracking area update request from the second terminal, the information for completing the tracking area update process of the second terminal is described. The base station according to claim 1, which is transmitted to a second terminal.
9. The base station according to any one of claims 1 to 8, wherein the first terminal and the second terminal are connected terminals that do not perform wireless communication.
10. The base station according to any one of claims 1 to 9 and
    With the first terminal
    With the second terminal
    A wireless system equipped with.

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