WO2017006548A1

WO2017006548A1 - Communication system, base station, and communication control method and device

Info

Publication number: WO2017006548A1
Application number: PCT/JP2016/003155
Authority: WO
Inventors: 誠藤波; 暢彦伊藤
Original assignee: 日本電気株式会社
Priority date: 2015-07-06
Filing date: 2016-07-01
Publication date: 2017-01-12

Abstract

[Problem] To provide a communication system, a base station, and a communication control method and device with which it is possible to reduce or avoid the congestion of a wireless access network without lowering the quality of experience (QoE) of a user. [Solution] The communication system detects the congestion state of the radio access network (RAN) of a first network (10) capable of accommodating a communication terminal, and the first network (10) switches, in accordance with the congestion state, the radio connection of at least one communication terminal (40) to a second network (20) at least the radio access network of which is physically independent from the first network (10).

Description

COMMUNICATION SYSTEM, BASE STATION, COMMUNICATION CONTROL METHOD AND DEVICE

The present invention relates to a communication system, and more particularly to a network congestion management technique.

In recent years, traffic has increased rapidly with the spread of smartphones. For this reason, congestion is likely to occur in a radio access network (RAN). The congestion of the RAN user plane causes packet loss or delay, and degrades the user's quality of experience communication. Therefore, in 3GPP (3rd Generation Partnership Project), studies on UPCON (User Plane CONgestion management) are being promoted as a management system for detecting and reducing congestion (Non-patent Document 1).

In UPCON, RCAF (RAN Congestion Awareness Function) is newly defined in the core network, and a congestion report (RCI: RAN user plane Congestion Information) is collected from the RAN side to detect congestion. The core network side can narrow down traffic and reduce congestion by executing bandwidth control, priority control, etc. according to RAN congestion.

However, if traffic regulation is performed on the core network side, even if RAN congestion can be avoided, the quality of communication (QoE: Quality of Experience) may be reduced on the regulated user side.

Therefore, an object of the present invention is to provide a communication system, a base station, a communication control method and an apparatus capable of reducing or avoiding congestion of a radio access network without reducing a user's QoE.

In the communication system according to the present invention, a first network capable of accommodating a communication terminal detects a congestion state of a radio access network, and the first network establishes a wireless connection of at least one communication terminal according to the congestion state. The first network and at least the radio access network are switched to a second network that is physically independent.
In the communication control method according to the present invention, a first network capable of accommodating communication terminals detects a congestion state of a radio access network, and the first network establishes a wireless connection of at least one communication terminal according to the congestion state. The first network and at least the radio access network are switched to a second network that is physically independent.
The base station according to the present invention is a base station in a network capable of accommodating communication terminals, and includes congestion detection means for detecting a congestion state of a radio access network of the network, and at least one communication terminal according to the congestion state. Control means for switching the wireless connection to at least another network in which the wireless access network is physically independent.
The communication control device according to the present invention comprises a congestion recognition means for recognizing a congestion state of a radio access network in a first network capable of accommodating a communication terminal, and a wireless connection of at least one communication terminal according to the congestion state, Control means for switching to a second network in which the first network and at least the radio access network are physically independent.

According to the present invention, congestion of the radio access network can be reduced or avoided without reducing the user's QoE.

FIG. 1 is a system configuration diagram showing a schematic functional configuration of a communication system according to a first embodiment of the present invention. FIG. 2 is a system configuration diagram showing a schematic functional configuration of a communication system according to the second embodiment of the present invention. FIG. 3 is a block diagram showing in more detail the configuration of the base station function in the radio access network of the communication system according to the second embodiment. FIG. 4 is a sequence diagram showing a communication control operation of the communication system according to the second embodiment. FIG. 5 is a system configuration diagram showing a schematic functional configuration of a communication system according to the third embodiment of the present invention. FIG. 6 is a block diagram showing in more detail the configuration of the core network function of the communication system according to the third embodiment. FIG. 7 is a sequence diagram showing a communication control operation of the communication system according to the third embodiment. FIG. 8 is a system configuration diagram showing a schematic functional configuration of a communication system according to the fourth embodiment of the present invention. FIG. 9 is a sequence diagram showing a communication control operation of the communication system according to the fourth embodiment. FIG. 10 is a system configuration diagram showing a schematic functional configuration of a communication system according to the fifth embodiment of the present invention. FIG. 11 is a sequence diagram showing a communication control operation of the communication system according to the fifth embodiment.

<Outline of Embodiment>
According to the embodiment of the present invention, the traffic of one or more terminals connected to or trying to connect to the radio access network is offloaded to another network according to the congestion level in the radio access network. For example, when congestion occurs in a radio access network, congestion of the radio access network can be reduced or avoided by offloading at least a part of user traffic related to the congestion to another network. Furthermore, since the offloaded traffic is maintained through other networks, it is possible to avoid a decrease in the QoE of the user. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. First Embodiment As illustrated in FIG. 1, a communication system according to a first embodiment of the present invention is a first network 10 and a second network 20 having at least a radio access function physically independent, and an external packet network. A plurality of communication terminals 40 including the Internet 30 and a plurality of communication terminals 40, the plurality of communication terminals 40 being connectable to the Internet 30 through a radio access network (RAN) and a core network (EPC: Evolved Packet Core) of the first network; To do.

As a desirable example, the first network 10 is a non-virtual network, and the second network 20 is a virtual network that can realize addition or deletion of network functions as necessary. As described in Non-Patent Document 1 described above, the first network has a function of detecting the presence or absence of RAN congestion or the RAN congestion level. The second network 20 has a wireless access function that allows at least the communication terminal 40 to be wirelessly connected, and the wireless access function is physically independent of the RAN function of the first network 10. The wireless access function of the second network 20 does not have to be the same access method as the RAN of the first network, but if the access method is different, the communication terminal 40 is provided with wireless communication means corresponding to both access methods. Need to be.

In the present embodiment, it is assumed that the second network 20 has the same wireless access function and Internet connection function as the RAN of the first network 10, and the communication terminal 40 can be connected to the Internet 30 through the second network. In the present embodiment, the first network 10 and the second network 20 are exemplified as a plurality of physically independent networks. However, three or more networks may be used.

The communication terminal 40 is a mobile radio station such as a mobile phone, a user equipment (UE: User Equipment), and the like, and has radio communication means that can be connected to both the networks 10 and 20. Hereinafter, a case where a plurality of communication terminals 40 are connected to the first network and congestion occurs in the RAN of the first network 10 will be described.

As shown in FIG. 1, when the occurrence of congestion is detected in the RAN of the first network 10 (operation S1), a part of the plurality of communication terminals 40 is connected with the EPC with or without the EPC. 2 Handover to the network 20 or switching (operation S2). More specifically, the number of communication terminals according to the level of congestion, a predetermined number of communication terminals, or a communication terminal performing low-priority communication is handed over to the second network or connected to the first network 10. By switching the request to the second network 20, RAN congestion of the first network 10 is reduced.

According to the present embodiment, unlike the above-described UPCON, congestion is reduced by offloading user traffic to another network instead of narrowing down user traffic on the core network side. A decrease can be avoided.

2. Second Embodiment According to the second embodiment of the present invention, when a base station of a non-virtual network detects congestion, a virtual network is provided to at least a part of a plurality of currently connected communication terminals according to the congestion level. Local handover (X2 handover) to the base station. Thereby, congestion of the radio access network in the non-virtual network can be reduced or avoided.

Desirably, the base station of the virtual network has a C-RAN architecture. In the C-RAN architecture, a baseband processing unit (BBU: BaseBand Unit) that performs modulation / demodulation processing and a remote radio unit (RRH: Remote Radio Head) including an antenna are separated and connected by a fronthaul such as an optical fiber. Is done. In particular, BBUs can be installed together in a center unit and implemented as a virtual BBU (vBBU: virtualized ： BBU) using a general-purpose server. In the C-RAN architecture adopting such a virtual BBU, RRH and vBBU can be dynamically allocated according to the congestion level detected by the base station. For example, consumption is achieved by stopping unused RRH and vBBU. It is possible to reduce electric power and improve the operation rate. The configuration and operation of the system according to the present embodiment will be described below with reference to FIGS.

2.1) System Configuration As illustrated in FIG. 2, the communication system according to the second embodiment of the present invention includes a non-virtual network 10 as a first network and a virtualized network 20a as a second network. The non-virtual network 10 is as described in the first embodiment. The virtual network 20 a includes a vBBU pool 21 a composed of a plurality of vBBUs configured on a server, and the vBBU pool 21 a is connected to the EPC 12 through the backhaul of the non-virtual network 10. The virtual network 20a may also be provided with a virtual core network vEPC similar to the EPC 12 of the non-virtualized network 10.

The base station on the virtual network side has a C-RAN architecture, and a vBBU pool 21a and a plurality of RRHs 22 are connected by a front hole 23. The front hole 23 is, for example, a CPRI (Common Public Radio Interface) or ORI (Open Radio Equipment Interface) network. In the C-RAN architecture, the number of vBBUs and RRHs to be used can be increased / decreased according to traffic conditions, so that power consumption can be reduced and the operating rate of the apparatus can be improved. Even in a C-RAN architecture using a normal BBU instead of being virtualized, the number of RRHs can be increased / decreased, so that power consumption can be reduced and the operating rate can be improved.

In such a communication system, when the base station 11 of the non-virtual network 10 detects the occurrence of congestion, the base station 11 performs handover to at least a part of the currently connected communication terminals 40 to the RRH 22 according to the congestion level. To control. The communication terminal 40 handed over to the RRH side maintains communication with the Internet 30 through the vBBU of the vBBU pool 21a and the EPC 12 of the non-virtual network 10. Hereinafter, the configurations of the base station 11 and the virtual baseband processing unit vBBU of the non-virtual network 10 will be described in more detail.

As shown in FIG. 3, the base station 11 includes a wireless communication unit 101 for wireless communication with a plurality of communication terminals 40 and a congestion detection unit 102 for detecting the congestion status of the wireless access network. The base station 11 also includes a handover control unit 103, a backhaul communication unit 104, an interface 105 for communicating with other base stations, and a control unit 106 that controls the overall operation of the base station. Base station operations such as wireless connection to the terminal, terminal control during handover, communication with the EPC 12, and the like.

The vBBU pool 21a is installed by aggregating and mounting a plurality of vBBUs on a virtual machine on the server, and realizes a base station function by the RRH 22 connected by the front hole 23 and the vBBU connected thereto. Each RRH 22 includes an antenna and a radio (RF: Radio Frequency) unit for wireless communication with a communication terminal in the cell. 3, it is assumed that cells sC1, sC2,..., Which are managed by the RRH 22 and vBBU and are smaller than the cell mC1, can be formed in the cell mC1 managed by the base station 11.

Each vBBU is mounted on the virtual machine of the server, and communicates with the fronthaul communication unit 201 for communicating with each RRH 22, the handover control unit 202, the backhaul communication unit 203 for communicating with the EPC 12, and other base stations. An interface 204 for performing the operation, and a control unit 205 for controlling the overall operation of the vBBU. Hereinafter, when at least one communication terminal 40 that is located in the overlapping region of the cells mC1 and sC1 and is performing radio communication with the cell mC1 performs handover from the cell mC1 to the predetermined cell sC1 triggered by the congestion detection of the base station 11 Will be explained.

2.2) Operation As illustrated in FIG. 4, it is assumed that the communication terminal 40 establishes a connection with the Internet 30 through the base station 11 and the non-virtual network 10 and performs communication (operation S301). In this state, when the congestion detection unit 102 of the base station 11 detects congestion in the radio access network or determines that there is a high possibility of congestion (operation S302), the control unit 106 performs handover according to the congestion level. Start the procedure. That is, the handover control unit 103 selects at least one communication terminal 40 as a handover target according to the congestion level and selects the handover destination cell sC1. In order to hand over at least one communication terminal 40 to the selected cell sC1, the handover control unit 103 transmits a handover request message to the vBBU pool 21a through the interface 105 (operation S303).

When the RRH and vBBU for managing the predetermined cell sC1 in the vBBU pool 21a are assigned, the handover control unit 202 of the vBBU determines whether or not the handover of the communication terminal 40 can be accepted (operation S304), and can be performed. If so, a handover request response is returned to the base station 11 (operation S305).

When the handover request response is received, the handover control unit 103 of the base station 11 transmits a handover instruction to the communication terminal 40 through the wireless communication unit 101 (operation S306). Upon receiving the handover instruction, the communication terminal 40 transmits a handover instruction response to the handover destination RRH and vBBU (operation S307). When receiving the handover instruction response, the handover control unit 202 of the vBBU transmits a path switching request to the EPC 12 (Operation S308). When the path to the communication terminal 40 is switched from the base station 11 side to the vBBU side in the EPC 12, A response to the path switching request is received from the EPC 12 (Operation S309). Thereby, the connection between the communication terminal 40 and the Internet 30 is established through the vBBU and the EPC 12, and the communication of the communication terminal 40 is continued (operation S310).

2.3) Effect According to the second embodiment of the present invention, when occurrence of congestion is detected in the RAN of the non-virtual network, a part of traffic of a plurality of currently connected communication terminals is transferred to the base station of the virtual network. By being offloaded locally, RAN congestion of the non-virtual network can be reduced or avoided. Further, as described above, since the base station of the virtual network has the C-RAN architecture using vBBU, it becomes possible to dynamically allocate RRH and vBBU according to the congestion level of RAN of the non-virtual network, Also, even in a C-RAN architecture using a normal BBU, the number of RRHs can be increased / decreased, so that power consumption can be reduced and the operating rate can be improved.

3. Third Embodiment According to the third embodiment of the present invention, when congestion is detected in a RAN of a non-virtual network, at least a part of a plurality of currently connected communication terminals is transferred to a base station of a virtual network. By executing the X2 or S1 handover, the path between the communication terminal and the Internet is switched from the non-virtual network to the virtual network. This reduces RAN congestion in the non-virtual network and also reduces the load on the core network in the non-virtual network. Further, as in the second embodiment described above, it is desirable that the base station of the virtual network has a C-RAN architecture. The configuration and operation of the system according to this embodiment will be described below with reference to FIGS.

3.1) System Configuration As illustrated in FIG. 5, the communication system according to the third embodiment of the present invention includes a non-virtual network 10 as a first network and a virtualized network 20b as a second network. . As in the second embodiment, the non-virtual network 10 includes a base station 11 and
The EPC 12 has a mobile backhaul (MBH) that connects them, and the EPC 12 includes a serving gateway (SGW) 1201, a packet data network gateway (PGW) 1202, a mobility management entity (MME) Management Entity) 1203, and RAN Congestion Awareness Function (RCAF) 1204.

Similarly to the second embodiment, the virtual network 20b includes a vBBU pool 21b composed of a plurality of vBBUs configured on a server, a vEPC 12b that is a virtual core network, and a mobile backhaul (MBH) that connects them. VEPC 12b includes a virtual serving gateway (vSGW) 1201b, a virtual packet data network gateway (vPGW) 1202b, and a virtual mobility management device (vMME) 1203b. The vEPC 12b and each vBBU are mounted on a server virtual machine.

As shown in FIG. 6, the base station on the virtual network side has a C-RAN architecture as in the second embodiment, and a vBBU pool 21b and a plurality of RRHs 22 are connected by a front hole 23. It is assumed that the cell configuration is the same. The MME 1203 in the EPC 12 on the non-virtual network side has a relocation control function and a target MME selection function in accordance with the congestion level, as will be described later, in addition to a normal mobility management function.

In such a communication system, when the base station 11 of the non-virtual network 10 detects the occurrence of congestion, the base station 11 notifies the MME 1203 of congestion information through the RCAF 1204 of the EPC 12. Upon receiving the congestion notification, the MME 1203 selects a target MME in the virtual network 20b and transmits an MME relocation request to the vEPC 12b. At least a part of the communication terminals 40 connected to the base station 11 is handed over to the RRH 22 and vBBU by the X2 handover similar to the second embodiment or the S1 handover led by the MME 1203, and the communication with the Internet 30 is maintained through the vEPC 12b. The Hereinafter, taking the cell configuration shown in FIG. 6 as an example, at least one communication terminal 40 that is located in the overlapping region of the cells mC1 and sC1 and is performing wireless communication with the cell mC1 is triggered by the congestion detection of the base station 11. A case where a handover is performed from the cell mC1 to the predetermined cell sC1 will be described.

3.2) Operation As illustrated in FIG. 7, it is assumed that the communication terminal 40 establishes a connection with the Internet 30 through the base station 11 and the SGW 1201 and PGW 1202 of the non-virtual network 10 and performs communication (operation S401). . In this state, when the congestion detection unit 102 of the base station 11 detects congestion in the radio access network or determines that there is a high possibility of congestion (operation S402), the control unit 106 includes congestion information including the congestion level. Is notified to the MME 1203 through the RCAF 1204 (operation S403). Upon receiving the congestion notification, the MME 1203 selects a target MME in the virtual network 20b (operation S404), transmits an MME relocation request to the virtual network 20b (operation S405), and at least one of the relocation procedure and handover target. The X2 / S1 handover procedure for the two communication terminals 40 is started (operation S406). When the handover is completed, a connection between the communication terminal 40 and the Internet 30 is established through the vBBU and vEPC 12b, and the communication of the communication terminal 40 continues (operation S407).

3.3) Effect According to the third embodiment of the present invention, when congestion occurrence is detected in the RAN of the non-virtual network, a part of traffic of a plurality of currently connected communication terminals is offloaded to the virtual network. This reduces RAN congestion and EPC load in the non-virtual network. Further, since the base station of the virtual network has the C-RAN architecture, RRH and vBBU can be dynamically allocated according to the RAN congestion level of the non-virtual network.

4). Fourth Embodiment According to the fourth embodiment of the present invention, when congestion occurs in a RAN of a non-virtual network, the core network of the non-virtual network takes the lead, and at least a part of a plurality of currently connected communication terminals Instructs the user to detach from the non-virtual network and attach to the virtual network. As a result, RAN congestion of the non-virtual network can be reduced, and the load on the core network in the non-virtual network can also be reduced. As in the second embodiment described above, it is desirable that the base station of the virtual network has a C-RAN architecture. Hereinafter, the configuration and operation of the system according to the present embodiment will be described with reference to FIGS.

As illustrated in FIG. 8, the basic configuration of the communication system according to the fourth embodiment of the present invention is the same as that of the third embodiment, so the same reference numerals are given and the description thereof is omitted. The communication control operation according to the present embodiment is different in that the communication terminal detach and retouch operations are used instead of the handover of the third embodiment. More specifically, when receiving the congestion notification, the MME 1203 of the EPC 12 in the non-virtual network 10 has a function of transmitting a detach request to at least some communication terminals and instructing retouch to the virtual network 20b. Hereinafter, taking the cell configuration shown in FIG. 6 as an example, at least one communication terminal 40 that is located in the overlapping region of the cells mC1 and sC1 and is performing wireless communication with the cell mC1 is triggered by the congestion detection of the base station 11. A case of retouching from the cell mC1 to the predetermined cell sC1 will be described.

9, it is assumed that the communication terminal 40 establishes a connection with the Internet 30 through the base station 11 and the SGW 1201 and PGW 1202 of the non-virtual network 10 and performs communication (operation S501). In this state, when the congestion detection unit 102 of the base station 11 detects congestion in the radio access network or determines that there is a high possibility of congestion (operation S502), the control unit 106 transmits the congestion information through the RCAF 1204 to the MME 1203. (Operation S503). Upon receiving the congestion notification, the MME 1203 designates a retouch destination (network ID or the like) for at least some communication terminals 40 corresponding to the congestion level among the connected communication terminals (operation S504), and each communication terminal 40 A detach request including retouch destination information is transmitted to (operation S505). As a result, the connection in the non-virtual network 12 between the communication terminal 40 that has received the detach request and the Internet 30 is released (operation S506).

The communication terminal 40 that has received the detach request transmits an attach request to the designated retouch destination virtual network 20b (operation S507). Accordingly, a connection is established in the virtual network 20b, and communication can be resumed between the communication terminal 40 and the Internet 30 (operation S508).

According to the fourth embodiment of the present invention, when congestion occurrence is detected in the RAN of the non-virtual network, the EPC takes the initiative to offload some traffic of a plurality of currently connected communication terminals to the virtual network. RAN congestion and EPC load in a non-virtual network can be reduced. Further, since the base station of the virtual network has the C-RAN architecture, RRH and vBBU can be dynamically allocated according to the RAN congestion level of the non-virtual network.

5). Fifth Embodiment According to the fifth embodiment of the present invention, when congestion occurs in the RAN of a non-virtual network, the communication terminal that is executing the attach procedure is instructed to switch the attach destination to the virtual network. As a result, deterioration of RAN congestion in the non-virtual network can be prevented, and an increase in the load on the core network in the non-virtual network can be avoided. As in the second embodiment described above, it is desirable that the base station of the virtual network has a C-RAN architecture. Hereinafter, the configuration and operation of the system according to the present embodiment will be described with reference to FIGS. 10 and 11.

As illustrated in FIG. 10, since the basic configuration of the communication system according to the fifth embodiment of the present invention is the same as that of the third embodiment, the same reference numerals are given and description thereof is omitted. According to the present embodiment, the EPC 12 instructs the communication terminal 40 to switch the attachment destination while the communication terminal 40 is executing the attachment procedure to the non-virtual network 10. More specifically, when receiving the congestion notification, the MME 1203 of the EPC 12 in the non-virtual network 10 has a function of instructing the communication terminal that has transmitted the attach request to switch the attachment destination to the virtual network 20b. In response to the attach destination switching instruction, the communication terminal 40 switches the transmission destination of the attach request to the virtual network 20b. Hereinafter, communication control according to the present embodiment will be described with reference to FIG.

As illustrated in FIG. 11, it is assumed that the communication terminal 40 transmits an attach request to the MME 1203 through the base station 11 (Operation S601), and the attach procedure is started (Operation S602). If the congestion detection unit 102 of the base station 11 detects congestion in the radio access network or determines that there is a high possibility of congestion when the attach procedure is being executed (operation S603), the control unit 106 The congestion information is notified to the MME 1203 through the RCAF 1204 (Operation S604). Upon receiving the congestion notification, the MME 1203 transmits a switching instruction message including the network ID of the attachment destination to at least a part of the communication terminals 40 that are executing the attach request procedure (Operation S605).

The communication terminal 40 that has received the attach destination switching instruction transmits an attach request to the virtual network 20b instructed as the switching destination (operation S606). Thereby, the vMME of the virtual network 20b establishes a connection between the communication terminal 40 and the Internet 30 through the vSGW and vPGW of the virtual network 20b (Operation S607), and the communication terminal 40 passes through the virtual network 20b. Communication with the Internet 30 is started.

According to the fourth embodiment of the present invention, when congestion occurs in the RAN of the non-virtual network, by instructing at least a part of the communication terminals that are performing the attach procedure to switch the attach destination to the virtual network. , An increase in the load on the RAN and the core network can be avoided. Further, since the base station of the virtual network has the C-RAN architecture, RRH and vBBU can be dynamically allocated according to the RAN congestion level of the non-virtual network.

6). Additional Notes Part or all of the above-described embodiments may be described as the following additional notes, but are not limited thereto.
(Appendix 1)
The first network that can accommodate the communication terminal detects the congestion state of the radio access network,
The first network switches the wireless connection of at least one communication terminal to a second network in which the first network and at least the radio access network are physically independent according to the congestion state;
Communications system.
(Appendix 2)
The communication system according to appendix 1, wherein the first network is a non-virtual network and the second network is a virtual network.
(Appendix 3)
The supplementary note 1 or 2, wherein the first network switches the wireless connection of the at least one communication terminal by a handover from the base station of the first network to the base station of the second network according to the congestion state. The communication system described.
(Appendix 4)
The communication system according to any one of appendices 1-3, wherein the traffic of the at least one communication terminal is offloaded to a path including a base station of the second network and a core network of the first network.
(Appendix 5)
The communication system according to any one of appendices 1-4, wherein the first network switches a wireless connection of the at least one communication terminal by a handover involving only a base station according to the congestion state.
(Appendix 6)
The communication system according to any one of appendices 1-3, wherein the traffic of the at least one communication terminal is offloaded to a path including a base station of the second network and a core network of the second network.
(Appendix 7)
The first network switches the wireless connection of the at least one communication terminal by a handover involving the core network of the first network and the core network of the second network according to the congestion state. The communication system according to any one of 3 and 6.
(Appendix 8)
In response to the congestion state, the first network transmits a detach request from the first network whose retouch destination is the second network to the at least one communication terminal. The communication system according to attachment 1 or 2, wherein the connection is switched.
(Appendix 9)
In response to the attach request from the at least one communication terminal, the first network transmits the attach destination switching instruction in which the attach destination is the second network in response to the congestion state, so that the at least one communication The communication system according to attachment 1 or 2, wherein the wireless connection of the terminal is switched.
(Appendix 10)
The communication system according to any one of appendices 1-9, wherein the function of the base station of the second network is separated into a remote radio station and a baseband processing unit.
(Appendix 11)
The first network that can accommodate the communication terminal detects the congestion state of the radio access network,
The first network switches the wireless connection of at least one communication terminal to a second network in which the first network and at least the radio access network are physically independent according to the congestion state;
Communication control method.
(Appendix 12)
A base station in a network capable of accommodating communication terminals,
Congestion detection means for detecting a congestion state of the wireless access network of the network;
Control means for switching a wireless connection of at least one communication terminal to another network at least a radio access network is physically independent according to the congestion state;
Base station with
(Appendix 13)
13. The base station according to appendix 12, wherein the control means switches the wireless connection of the at least one communication terminal by handover to the base station of the other network according to the congestion state.
(Appendix 14)
14. The base station according to appendix 12 or 13, wherein the control means switches the wireless connection of the at least one communication terminal by a handover involving only the base station according to the congestion state.
(Appendix 15)
A congestion recognition means for recognizing a congestion state of the radio access network in the first network capable of accommodating communication terminals;
Control means for switching the wireless connection of at least one communication terminal to a second network in which the first network and at least the wireless access network are physically independent according to the congestion state;
A communication control device.
(Appendix 16)
The communication according to appendix 15, wherein the control means switches the wireless connection of the at least one communication terminal by a handover from the base station of the first network to the base station of the second network according to the congestion state. Control device.
(Appendix 17)
The communication control device according to appendix 15 or 16, wherein the traffic of the at least one communication terminal is offloaded to a path including a base station of the second network and a core network of the first network.
(Appendix 18)
The communication control device according to appendix 15 or 16, wherein the traffic of the at least one communication terminal is offloaded to a path including a base station of the second network and a core network of the second network.
(Appendix 19)
The control means switches the wireless connection of the at least one communication terminal by a handover involving the core network of the first network and the core network of the second network according to the congestion state. Or the communication control apparatus of 18.
(Appendix 20)
According to the congestion state, the control means transmits a detach request from the first network to which the retouch destination is the second network, to the at least one communication terminal, thereby wirelessly connecting the at least one communication terminal. The communication control device according to attachment 15, wherein the communication control device is switched.
(Appendix 21)
In response to the attach request from the at least one communication terminal, the first network transmits the attach destination switching instruction in which the attach destination is the second network in response to the congestion state, so that the at least one communication The communication control device according to attachment 15, wherein the wireless connection of the terminal is switched.
(Appendix 22)
A program for causing a computer to function as a base station in a network capable of accommodating communication terminals,
A congestion detection function for detecting a congestion state of the wireless access network of the network;
A control function for switching a wireless connection of at least one communication terminal to another network at least a radio access network is physically independent according to the congestion state;
A program for realizing the above on the computer.
(Appendix 23)
A program for causing a computer to function as a communication control device,
A congestion recognition function for recognizing the congestion state of the radio access network in the first network capable of accommodating communication terminals;
A control function for switching the wireless connection of at least one communication terminal to a second network in which the first network and at least the radio access network are physically independent according to the congestion state;
A program for realizing the above on the computer.

The present invention is generally applicable to mobile communication systems.

10 First network (non-virtual network)
11 Base station 12 EPC
12b vEPC
20

Second network

20a, 20b

Virtual network

21a, 21b vBBU pool 22 RRH
23 Front hall

Claims

The first network that can accommodate the communication terminal detects the congestion state of the radio access network,
The first network switches the wireless connection of at least one communication terminal to a second network in which the first network and at least the radio access network are physically independent according to the congestion state;
Communications system.
The communication system according to claim 1, wherein the first network is a non-virtual network and the second network is a virtual network.
The first network switches the wireless connection of the at least one communication terminal by a handover from a base station of the first network to a base station of the second network according to the congestion state. The communication system according to 1.
The communication system according to any one of claims 1 to 3, wherein traffic of the at least one communication terminal is offloaded to a path including a base station of the second network and a core network of the first network.
The communication system according to any one of claims 1 to 4, wherein the first network switches wireless connection of the at least one communication terminal by handover involving only a base station according to the congestion state.
The communication system according to any one of claims 1 to 3, wherein traffic of the at least one communication terminal is offloaded to a path including a base station of the second network and a core network of the second network.
The first network switches the wireless connection of the at least one communication terminal by a handover involving a core network of the first network and a core network of the second network according to the congestion state. The communication system according to any one of -3 and 6.
In response to the congestion state, the first network transmits a detach request from the first network whose retouch destination is the second network to the at least one communication terminal. The communication system according to claim 1 or 2, wherein the connection is switched.
In response to the attach request from the at least one communication terminal, the first network transmits the attach destination switching instruction in which the attach destination is the second network in response to the congestion state, so that the at least one communication The communication system according to claim 1, wherein the wireless connection of the terminal is switched.
The communication system according to any one of claims 1 to 9, wherein a function of a base station of the second network is separated into a remote radio station and a baseband processing unit.
The first network that can accommodate the communication terminal detects the congestion state of the radio access network,
The first network switches the wireless connection of at least one communication terminal to a second network in which the first network and at least the radio access network are physically independent according to the congestion state;
Communication control method.
A base station in a network capable of accommodating communication terminals,
Congestion detection means for detecting a congestion state of the wireless access network of the network;
Control means for switching a wireless connection of at least one communication terminal to another network at least a radio access network is physically independent according to the congestion state;
Base station with
The base station according to claim 12, wherein the control means switches the wireless connection of the at least one communication terminal by a handover to a base station of the other network according to the congestion state.
The base station according to claim 12 or 13, wherein the control means switches the wireless connection of the at least one communication terminal by a handover involving only the base station according to the congestion state.
A congestion recognition means for recognizing a congestion state of the radio access network in the first network capable of accommodating communication terminals;
Control means for switching the wireless connection of at least one communication terminal to a second network in which the first network and at least the wireless access network are physically independent according to the congestion state;
A communication control device.
16. The control unit according to claim 15, wherein the control means switches the wireless connection of the at least one communication terminal by a handover from a base station of the first network to a base station of the second network according to the congestion state. Communication control device.
The communication control device according to claim 15 or 16, wherein the traffic of the at least one communication terminal is offloaded to a path including a base station of the second network and a core network of the first network.
The communication control device according to claim 15 or 16, wherein the traffic of the at least one communication terminal is offloaded to a path including a base station of the second network and a core network of the second network.
The control means switches the wireless connection of the at least one communication terminal by a handover involving the core network of the first network and the core network of the second network according to the congestion state, The communication control device according to 16 or 18.
According to the congestion state, the control means transmits a detach request from the first network to which the retouch destination is the second network, to the at least one communication terminal, thereby wirelessly connecting the at least one communication terminal. The communication control device according to claim 15, wherein the communication control device is switched.
In response to the attach request from the at least one communication terminal, the first network transmits the attach destination switching instruction in which the attach destination is the second network in response to the congestion state, so that the at least one communication The communication control device according to claim 15, wherein the wireless connection of the terminal is switched.
A program for causing a computer to function as a base station in a network capable of accommodating communication terminals,
A congestion detection function for detecting a congestion state of the wireless access network of the network;
A control function for switching a wireless connection of at least one communication terminal to another network at least a radio access network is physically independent according to the congestion state;
A program for realizing the above on the computer.
A program for causing a computer to function as a communication control device,
A congestion recognition function for recognizing the congestion state of the radio access network in the first network capable of accommodating communication terminals;
A control function for switching the wireless connection of at least one communication terminal to a second network in which the first network and at least the radio access network are physically independent according to the congestion state;
A program for realizing the above on the computer.