JP2017229022A - Radio communication system and communication method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system capable of forming a mobile network in an autonomous distributed manner without concentrating traffic in a core network.SOLUTION: A radio communication system includes: radio base stations 100 having a radio access function unit for forming a radio access section; and a core network 200 for accommodating the radio base stations 100. Among function units for forming the core network 200, a gateway function unit for transmitting user data and having a connection function to an external network including the Internet 300 is arranged on each of the radio base stations 100. Among the function units for forming the core network 200, at least part of a control plane function unit related to a control plane is arranged on the Internet 300.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wireless communication system.

  Mobile communication is rapidly spreading in recent years, and a standard cellular radio communication system established by 3GPP (Third Generation Partnership Project) called 3G or LTE (Long Term Evolution) is widely used. A mobile communication service provided by a cellular radio communication system is generally operated in a license band, and a carrier licensed to use a frequency performs the mobile communication service using the frequency band. On the other hand, a frequency band called an unlicensed band is prepared as a frequency band for wireless communication. The frequency band of the unlicensed band is characterized by a frequency band that can be used by anyone, although the device needs to satisfy the standard. For example, IEEE802.11 standard wireless LAN is widely used in 2.4GHz band and 5GHz band unlicensed band.

  Mobile communication traffic continues to increase rapidly due to the spread of smartphones and the like, and in the future, there may be a shortage of frequencies in the license band to which mobile operators are allocated. For this reason, in mobile communication, a scheme for operating LTE even in an unlicensed band is being studied. For example, LAA (Licensed Assisted Access) (prior art document 1) studied by 3GPP is an example. LAA is a technology that simultaneously uses a license band and an unlicensed band in the 5 GHz band between a UE (terminal, user equipment) and a base station (eNodeB), and it is assumed that there is a communication path in the license band. In addition, this is a technology that uses the unlicensed band for downlink communication by LTE. Based on this technology, a technology called MultiFire has been proposed by the MultiFire Alliance (http://www.multefire.org/), and it will be a technology that enables LTE services to be performed by an unlicensed band alone. It is. LAA requires the integrated use with the license band, whereas MultiFire can be used only with the unlicensed band, and can be used not only in the downlink direction but also in the uplink / downlink direction. For this reason, for example, there is a merit that a communication carrier without a license for a license band can provide a mobile communication service compliant with LTE, and future practical use is expected.

  MultiFire can provide mobile communication in an unlicensed band, and anyone can implement mobile communication if equipment is prepared. However, since the MultiFire is basically used in an unlicensed band in accordance with the LTE standard, the equipment on the network side of the MultiFire requires a mobile core network device in addition to the base station. In LTE, these devices are called EPC (Enhanced Packet Core) (prior art document 2). The EPC is composed of a plurality of function groups, and provides functions such as UE authentication, mobility management, and policy control. As a component of EPC, an HSS (Home Subscriber Server) stores subscriber information for authenticating an LTE UE. MME (Mobility Management Entity) controls UE mobility management. The S-GW (Serving Gateway) and P-GW (PDN Gateway) operate in cooperation to perform a traffic handover function when the UE moves. A PCRF (Policy and Charging Rules Function) provides a policy control function such as QoS.

3GPP, TR 36.889 V13.0.0 (2015-06), Technical Specification Group Radio Access Network; Study on Licensed-Assisted Access to Unlicensed Spectrum; (Release 13) 3GPP, TS 23.401 V13.6.1 (2016-03), Technical Specification Group Services and System Aspects; General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access (Release 13)

  Since the MultiFire base station operates on the premise that the EPC function exists as a core network, it is necessary to prepare an EPC for use. Therefore, for example, a base station alone cannot operate like a wireless LAN. EPC is premised on providing LTE mobile services on a relatively large scale, and cost is an issue in preparing the equipment. EPC is basically assumed to be used within a single operator network, and provides functions such as UE mobility management within the operator network, and access to the Internet is P -Take the configuration aggregated in the GW. However, as a use case of MultiFire, it is conceivable to make free use of various network lines by taking advantage of the free installation. When providing a mobile service in such a use case, it is conceivable to deploy an EPC function on a cloud server on the Internet and accommodate a base station connected to any line. Since the P-GW serves as an anchor point for user data and communication traffic is aggregated, there are problems that bottlenecks such as congestion occur and Internet access via the anchor point increases delay.

  As described above, when an EPC that is connected to various networks and accommodates a MultiFire base station that is freely installed by a user is deployed on the network, the EPC may be deployed on a cloud server. In EPC, there is a possibility that a bottleneck may occur due to concentration of traffic, and there is a problem that EPC is expensive.

  In order to achieve the above object, the present invention provides a radio communication system comprising a radio base station having a radio access function unit forming a radio access section and a core network accommodating a plurality of radio base stations, Among the functional units forming the core network, a gateway functional unit that transmits user data and has a function of connecting to an external network including the Internet is provided in the radio base station, and control is performed among the functional units that form the core network. It is characterized in that at least a part of the control plane function unit related to the plane is arranged on the Internet.

  According to the present invention, it is possible to easily and cost-effectively deploy the core network function on the network side when providing a mobile communication service by a radio base station, and autonomously decentralized without concentrating traffic on the core network. It becomes possible to form a mobile network. Further, in the present invention, there is no need to change the function to the user terminal, and the function can be provided by the network side device.

The figure which shows the topology of the radio | wireless communications system which concerns on this invention Diagram showing LTE topology 1 is a configuration diagram of a radio base station according to an embodiment of the present invention. The block diagram of MME which concerns on one Embodiment of this invention Configuration of HSS according to an embodiment of the present invention Example of management information of UE belonging P-GW management DB in HSS according to one embodiment of the present invention Example of management information of radio base station management DB in HSS according to one embodiment of the present invention Sequence diagram when wireless base station is connected to mobile network Sequence diagram when a radio base station is deleted from the mobile network Sequence diagram showing the procedure of UE belonging to a mobile network Sequence diagram showing a procedure for de-assigning UE from mobile network Sequence diagram when starting communication between UEs connected to different radio base stations

  A radio communication system according to an embodiment of the present invention will be described with reference to the drawings. The wireless communication system according to the present embodiment is LTE or a wireless communication system similar to LTE, and has a processing function (HSS, MME, PCRF) of EPC C-Plane (Control Plane) on a cloud server. At the same time, an E-PC S-GW / P-GW U-Plane (User Plane) function is provided in the base station.

  FIG. 1 shows a topology of a wireless communication system according to the present invention. Each radio base station 100 in FIG. 1 has a function deployment in which a function of an eNodeB that is an LTE standard base station and P-GW and S-GW are integrated. In the present invention, by providing the P-GW and S-GW functions in each base station 100, one base station 100 has a function equivalent to one P-GW and S-GW. All base stations 100 are connected to the EPC 200 installed on the cloud server of the Internet 300, and transmit and receive C-Plane signals. All base stations 100 have a P-GW so that a multi-P-GW configuration is obtained as a whole. Here, the functional units of the EPC 200 deployed on the cloud server, that is, deployed on the Internet 300 include at least the MME 210 and the HSS 220.

  On the other hand, FIG. 2 shows a standard LTE system topology for comparison. Basically, in the LTE standard, one P-GW is provided for a connection point to a PDN (Packet Data Network). Therefore, the P-GW provides a route for access to the Internet to a mobile network under its control. Therefore, it is common for a P-GW to be deployed in a small number, such as one location, for one managed mobile network.

  FIG. 3 shows a functional configuration diagram of the radio base station in the present embodiment. The radio base station 100 includes a P-GW function unit 121 corresponding to the LTE P-GW function and an S-GW function unit 122 corresponding to the S-GW function, and also corresponds to a standard LTE eNodeB function. An eNodeB function unit 110 is provided. Furthermore, the radio base station 100 includes an encryption path setting function unit 130. As shown in FIG. 2, the encrypted path setting function unit 130 sets an encrypted path between the base stations 100 on the Internet 300 to form a closed network. An implementation example of this encryption path setting function is an Internet VPN function using functions such as IPsec, PPTP (Point to Point Tunneling Protocol), and SSL (Secure Socket Layer) technology.

  FIG. 4 shows a functional configuration of the MME in the present technology. The MME 210 includes, in addition to the LTE standard MME function unit 211, an inter-base station connection management unit 212 and a UE belonging P-GW management unit 213.

  FIG. 5 shows the functional configuration of the HSS. The HSS 220 of the present invention includes a UE belonging P-GW management DB (Data Base) 222 and a radio base station authentication management DB 223 in addition to the LTE standard HSS function unit 221.

  FIG. 6 shows a configuration example of the UE belonging P-GW management DB. As shown in FIG. 6, the UE manages the current belonging destination in a database based on the ID for identifying the P-GW function unit 121 of the wireless base station 100 to which the UE belongs and the IP address thereof.

  FIG. 7 shows an example of management information in the radio base station authentication management DB. As shown in FIG. 7, the radio base station 100 uses the identification ID (P-GW ID) of the P-GW function unit 121 of each base station 100 and the base station 100 to the mobile network configured by the present invention. Are managed by a database for managing authentication information for authenticating the connection, a registration status in the mobile network, and a setting status of an encryption path between base stations.

  FIG. 8 shows a sequence when the radio base station of the present invention is connected to a mobile network. When the wireless base station 100 is connected to the Internet line and can access the EPC 200 on the Internet 300, the wireless base station 100 makes a registration request including the P-GW ID that is its own identifier (step S1).

  In the EPC 200, the inter-base station connection management unit 212 of the MME 210 receives the registration request (step S2), and makes an authentication request to the radio base station authentication management DB 223 of the HSS 220. The HSS 220 refers to the authentication information of the base station from the P-GW ID (step S3), and performs authentication processing with the radio base station 100 (step S4). If the authentication is successful, the HSS 220 permits registration and performs registration in the radio base station authentication management DB 223 (steps S5 to S7). The registered radio base station 100 requests a base station list already registered in the mobile network registered in the inter-base station connection management unit 212 of the MME 210 (step S8). The MME 210 obtains information from the radio base station authentication management DB 223 of the HSS 220 (steps S9 and S10), and returns a list of base stations including the P-GW IP address (step S11). Using the IP address information of the base station, the radio base station 100 sets an encryption path for each base station (step S12). The setting result of the encryption path with each base station is notified to the MME 210 (steps S13 and S14) and stored in the radio base station authentication management DB 223 of the HSS 220 (step S15).

  FIG. 9 shows a sequence when the radio base station of the present invention is deleted from the mobile network. The leaving radio base station 100 transmits a deletion request including its own P-GW ID to the inter-base station connection management unit 212 of the MME 210 (step S21). The MME 210 changes the registration content of the wireless base station authentication management DB 223 of the HSS 220 and deletes the attribution (steps S22 and S23). Thereafter, the completion result is notified (steps S24 and S25). Although this procedure exemplifies a case where there is a request from the base station 100, the inter-base station connection management unit 212 of the MME 210 autonomously performs radio base station authentication when the existence of the radio base station 100 cannot be confirmed for a certain period of time. The registration of the management DB 223 may be changed.

  FIG. 10 shows a procedure for belonging to a mobile network according to the present invention. The UE 10 performs wireless connection and authentication processing in the same manner as a normal LTE procedure, and attaches to the mobile network (steps S31 to S35). In this attach process, the UE's belonging P-GW management unit 213 of the MME 210 stores the information of the belonging P-GW in the UE's belonging P-GW management DB 222 of the HSS 220 (steps S36 to S38). .

  FIG. 11 shows a procedure for canceling the attribution of the UE to the mobile network according to the present invention. The UE 10 performs a detach process in the same manner as a normal LTE procedure (steps S41 to S43). In this detach process, the UE's belonging P-GW management unit 213 of the MME 210 instructs the UE's belonging P-GW management DB 222 of the HSS 220 to change the information of the belonging P-GW and cancels the belonging. (Step S44).

  FIG. 12 shows a procedure for starting communication between UEs connected to different radio base stations in the mobile network of the present invention. Here, the start of communication means, for example, a voice call by a telephone number or transmission of a packet to a destination IP address.

  When the UE 10 # 1 belonging to the radio base station 100 # 1 starts communication with the UE 10 # 2 belonging to the radio base station 100 # 2, the UE 10 # 1 issues a call request to the radio base station 100 # 1. This is performed (step S51). Here, it is assumed that the encryption path is already set between the base stations between the radio base stations 100 # 1 and # 2 (step S50).

  The radio base station 100 # 1 makes an inquiry to the UE's belonging P-GW management unit 213 of the MME 210 in order to make an inquiry to the EPC about the IP address of the P-GW to which the UE 10 # 2 belongs (step S52). The MME 210 refers to the belonging P-GW management DB 222 and the radio base station authentication management DB 223 of the HSS 220, obtains and returns the IP address of the belonging P-GW of the UE 10 # 2 (steps S53 to S56).

  Using the information, radio base station 100 # 1 makes a call to radio base station 100 # 2 (step S57), and radio base station 100 # 2 calls UE 10 # 2 to make a call. Communication between UEs is started by notifying (step S58).

  Although one embodiment of the present invention has been described in detail above, the present invention is not limited to this. For example, in the above embodiment, the MME 210 and the HSS 220 are deployed on the cloud server. However, if the MME 210 and the HSS 220 are installed on the Internet 300, the deployment mode is not limited.

  In the above embodiment, the P-GW function unit 121 and the S-GW function unit 122 are individually mounted in the radio base station 100. However, both function units are integrated as one P / S-GW function unit. You may make it mount in.

  In the above embodiment, the LTE base station of an unlicensed band such as MultiFire has been described in detail. However, the present invention can also be implemented in a radio base station using a license band.

DESCRIPTION OF SYMBOLS 100 ... Wireless base station 110 ... eNodeB functional part 121 ... P-GW functional part 122 ... S-GW functional part 130 ... Encryption path setting functional part 200 ... EPC
210 ... MME
211 ... Standard MME function unit 212 ... Inter-base station connection management unit 213 ... UE belonging P-GW management unit 220 ... HSS
221 ... Standard HSS function unit 222 ... UE belonging P-GW management DB
223 ... Wireless base station authentication management DB
300 ... Internet

Claims (6)

A wireless communication system comprising a wireless base station having a wireless access function unit forming a wireless access section and a core network accommodating a plurality of wireless base stations,
A gateway function unit that transmits user data among the function units forming the core network and has a function of connecting to an external network including the Internet is provided in the radio base station,
A wireless communication system, wherein at least a part of a control plane function unit related to a control plane among the function units forming the core network is arranged on the Internet. The control plane function unit provided on the Internet manages terminal position management by associating identification information of the gateway function unit in the radio base station to which the user terminal belongs and the IP address of the gateway function unit. The wireless communication system according to claim 1, further comprising a functional unit. The gateway function unit includes a VPN function unit that forms a VPN (Virtual Private Network) via the Internet,
The virtual closed network in which each radio base station is accommodated is formed by forming an encrypted communication path connecting a plurality of radio base stations in a mesh form on the Internet. Wireless communication system. The wireless communication system according to any one of claims 1 to 3, wherein each functional unit in the wireless communication system has a function and an interface defined by LTE (Long Term Evolution). The radio access function unit has an eNodeB function and an interface that provide a radio access function,
The gateway function unit has at least a PDN (Packet Data Network) -Gateway function and interface;
The wireless communication according to claim 4, wherein the control plane function unit deployed on the Internet has at least a function and interface of MME (Mobility Management Entity) and a function and interface of HSS (Home Subscriber Server). system. A communication method between user terminals in a radio communication system including a radio base station having a radio access function unit that forms a radio access section and a core network that accommodates a plurality of radio base stations,
A gateway function unit that transmits user data among the function units forming the core network and has a function of connecting to an external network including the Internet is provided in the radio base station,
Among the functional units forming the core network, at least part of the control plane functional unit related to the control plane is deployed on the Internet,
The control plane function unit deployed on the Internet is a terminal location management that manages the location of the user terminal by associating the identification information of the gateway function unit in the radio base station to which the user terminal belongs and the address information of the gateway function unit It has a functional part,
The gateway function unit includes a VPN function unit that forms a VPN (Virtual Private Network) via the Internet,
Forming a virtual closed network in which each radio base station is accommodated by forming an encrypted communication path connecting a plurality of radio base stations in a mesh shape on the Internet,
The control plane function unit deployed on the Internet refers to the terminal location information management unit when a call is made from a user terminal, and determines the IP address of the gateway function unit to which the partner user terminal belongs, In a radio communication system, wherein a radio base station to which a terminal belongs is notified, and the radio base station makes a call to a partner user terminal via the encrypted communication path for the notified IP address Communication method.

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