KR20190106048A - Method for controlling mobility of a terminal in a distributed core system - Google Patents

Abstract

A method for controlling mobility of a terminal in a distributed core system is provided. The method performed by a controller connected to a central core device to control mobility of a terminal in a distributed core system comprising the central core device that manages mobility and multiple edge core devices that process data under control of the central core device, comprises the steps of: receiving mobility information of the terminal from mobility information of the terminal; identifying based on the mobility information a serving switch connected to a serving edge core device of the terminal and a target switch connected to a target edge core device of the terminal; transmitting a changed flow rule to the serving switch; and transmitting a newly generated flow rule to the target switch, wherein the changed flow rule is set to cause the serving switch to be conveyed to the target switch through a backhaul transmission network, and the newly generated flow rule is set to cause data of the terminal transmitted from the serving switch to be processed by the target edge core device and then be transmitted to the terminal.

Description

METHOOD FOR CONTROLLING MOBILITY OF A TERMINAL IN A DISTRIBUTED CORE SYSTEM}

The present invention relates to a method for controlling mobility of a terminal in a distributed core system and to a handover technique of a terminal.

The 4G core network structure is a centralized structure in which Mobility Management Entity (MME), Serving Gateway (SGW), and PDN Gateway (PGW) are centrally located. In the 4G core network structure, a terminal interworks with an external packet network such as the Internet via a base station, SGW, and PGW to receive an Internet service. Core gateways such as SGW and PGW not only perform functions such as terminal authentication and IP address assignment, but also serve as anchoring points when moving terminals. Even if the terminal moves, the core gateway does not change, and while maintaining the terminal IP through the new tunneling configuration with the moved base station, it is possible to seamlessly receive data traffic even in the moved position.

However, in the 5G era, when the core gateway is located in the central office, network operators incur a lot of costs. 5G mobile communication network should provide throughput of 1Gbps per terminal and about 20Gbps per base station, which is about 20 times more traffic than 4G. Therefore, when the 4G core network is located in the center, the traffic of the transmission network section between the base station and the core gateway also increases by at least 20 times, in which case a huge transmission network investment cost is required.

Unlike the 4G core network structure, the proposed 5G core network structure is a core gateway that forwards and controls a user plane function (UPF), which is a core gateway that handles traffic, at an edge node or base station site in each region. Place CPF (Control Plane Function) at central office. In this way, by deploying core gateways in each region, it is possible to efficiently handle 5G traffic, which is more than 20 times, without having to increase the backhaul transmission network by distributing the traffic to each regional office rather than processing all the central offices. As a result, the transmission network investment can be reduced.

However, when the core gateways are distributed and distributed in the local offices in this way, there is a need for a method of efficiently providing mobility when the terminal moves beyond the offices. That is, when an edge station that first connects an anchoring point is maintained, when the terminal moves beyond the edge, tunneling between edges is required.

In extreme cases, when the terminal moves through multiple edges, continuous tunneling is generated from the initial anchoring point to the edge moved, and in this case, a large amount of traffic is sent to multiple edges. ), There is a problem that efficient traffic processing cannot be performed.

Problems to be solved by the present invention are a plurality of edge core devices for processing data in a user plane, and a central core device for controlling a plurality of edge core devices in a control plane and manages the mobility of the terminal In a distributed core system including a terminal, a method of controlling mobility of a terminal capable of maintaining service continuity while maintaining a session even though the terminal moves between edge core devices is provided.

According to one aspect of the present invention, a mobility control method includes a central core device for managing mobility and a plurality of edge core devices for processing data according to the control of the central core device. A method for controlling mobility of a terminal by a controller connected to the terminal, the method comprising: receiving mobility information of the terminal from the central core apparatus, a serving switch connected to a serving edge core apparatus of the terminal based on the mobility information, and a target of the terminal; Identifying a target switch connected to an edge core device, transmitting a changed flow rule to the serving switch, and transmitting a newly generated flow rule to the target switch, wherein the changed flow rule is the serving switch. Through the backhaul network Is set to forward to the target switch, the flow rule newly generated is set to transmit to the terminal after they have been processed by the data from the MS received from the serving switch to the target edge device core.

The newly generated flow rule further includes a flow entry configured to transmit downlink data received through the Internet network and uplink data received from the terminal after being processed by the target edge core device, and newly generated. After transmitting a flow rule, receiving handover completion information of the terminal from the central core device, transmitting a flow rule requesting deletion of a flow entry set to be delivered to the target switch to the serving switch; And transmitting, to the target switch, a flow rule requesting deletion of a flow entry for data received from the serving switch.

Prior to receiving the handover request information, receiving the network connection information of the terminal from the central core device, and transmitting a newly generated flow rule to the serving switch, the serving switch The newly generated flow rule transmitted to the mobile station may include a flow entry configured to transmit downlink data received through the Internet network and uplink data received from the terminal after being processed by the serving edge core device.

The flow entry may include a match field for setting an in-network identifier assigned by the terminal from the central core device, a data inflow port into which the data flows in, and an action field for defining a port for outputting data introduced into the data inflow port. The in-network identifier may be assigned when the central core device assigns an IP address to the terminal, and may be included in data of the terminal to identify a subscriber.

The controller and the switch may communicate via Software Defined Networks (SDN) protocol.

According to another aspect of the present invention, a mobility control method includes a serving edge core device in a distributed core system including a central core device for managing mobility and a plurality of edge core devices for processing data according to control of the central core device; A method of controlling a mobility of a terminal by a connected serving switch, the method comprising: receiving a changed flow rule according to a handover request of the terminal from a controller connected to the central core device, and downlink data of the terminal according to the changed flow rule To the target switch via a backhaul transmission network, and downlink data of the terminal is transferred from the target switch to a target edge core device connected to the target switch, and processed by the target edge core device. It is then delivered to the terminal.

The changed flow rule may include a flow entry in which a port connected between the serving switch and the internet network is set as a data inflow port, and a port connected between the serving switch and the backhaul transport network is set as a data output port.

After the step of transmitting to the target switch, receiving the changed flow rule according to the handover completion of the terminal from the controller, and deleting all of the flow entry of the terminal according to the changed flow rule have.

Before receiving the flow rule, receiving a flow rule according to the network connection of the terminal from the controller, and uplink data of the terminal and downlink data of the terminal to the flow rule according to the network connection And processing according to the network connection, wherein the uplink data of the terminal and the downlink data of the terminal are processed by the serving edge core device and then set to be transmitted to the terminal. Can be.

The flow rule according to the network connection is a flow entry in which a port connected between the serving switch and the internet network is set as a data inflow port and a port connected between the serving switch and the serving edge core device is set as a data output port, and the data inflow port. A port connected between the serving switch and the serving edge core device is set, and a port connected between the serving switch and the base station to which the terminal is connected as a data output port, and a flow entry and data inlet port connected between the base station and the serving switch. A flow entry in which a port is set and a port connected between the serving switch and the serving edge core device as a data output port, and a port connected between the serving switch and the serving edge core device as the data inflow port is set and data output The Trojan the serving switch and the port coupled to the Internet manganese may include a flow entry set.

According to another feature of the present invention, a mobility control method includes a target core core device in a distributed core system including a central core device for managing mobility and a plurality of edge core devices for processing data according to the control of the central core device. A target switch connected to a terminal to control mobility of a terminal, the method comprising: receiving a flow rule generated according to a handover request of the terminal from a controller connected to the central core device, and a serving switch is connected to the terminal according to the flow rule; Receiving data in service from the serving switch, and processing data received from the serving switch according to the flow rule, wherein the flow rule is configured to receive data received from the serving switch from the target edge core. After being processed by the device and sent to the terminal Is set.

After the transmitting, receiving the changed flow rule from the controller according to the completion of the handover of the terminal, and deleting the flow entry for the data received from the serving switch according to the changed flow rule. can do.

And after receiving the changed flow rule, processing uplink data of the terminal and downlink data of the terminal according to the changed flow rule, wherein the changed flow rule includes uplink data of the terminal. After the is processed by the target edge core device, it is transmitted to the Internet network, and the downlink data of the terminal may be set to be delivered to the terminal after being processed by the target edge core device.

The generated flow rule and the changed flow rule may be set to have the same network identifier of the data, and the network identifier may be given when the IP address of the terminal is allocated.

The serving switch and the target switch are connected through a backhaul transmission network, and the flow rule is set as relationship information between a data inflow port and a data output port, and the data inflow port and the data output port are the target switch and the data switch. Any one of a first port connected between a backhaul transmission network, a second port connected between the target switch and the Internet network, a third port connected between the target switch and the target edge core device, and a fourth port connected between the target switch and the base station It may be a port.

According to an embodiment of the present invention, in a 5G network environment in which a core network is distributed to a regional edge office rather than a central office, when a terminal moves between edge offices, it efficiently handles traffic and performs session continuity. Can provide.

In addition, even if the terminal moves between edge stations, the service continuity can be provided by providing service continuity at the same time without being dependent on the anchoring point to which the terminal is initially connected, and the anchor-free traffic processing can be performed. Cost effective traffic handling

1 illustrates a configuration of a distributed core system according to an embodiment of the present invention.
2 illustrates a state in which a terminal is connected to a serving edge core device before moving according to an embodiment of the present invention.
3 illustrates a state in which inter-handover occurs between edge core devices due to movement of a terminal according to an embodiment of the present invention.
4 illustrates a state in which inter handover between edge core devices is completed according to an embodiment of the present invention.
5 illustrates an organic connection flow diagram between components of a distributed core system according to an embodiment of the present invention.
6 is a flowchart illustrating an organic connection between components of a distributed core system when a handover occurs according to an embodiment of the present invention.
7 is a flowchart illustrating an organic connection between components of a distributed core system when handover is completed according to an embodiment of the present invention.
8 is a hardware block diagram of a server device according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

In addition, the terms “… unit”, “… unit”, “… module” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. Can be.

In the present specification, a terminal is a user device, and includes a device, a user equipment (UE), a mobile equipment (ME), a mobile station (MS), a mobile terminal (MT), a subscriber station (subscriber station, Terms such as SS, Portable SubscriberStation (PSS), User Equipment (UE), Access Terminal (AT), etc., may be referred to as mobile terminal, subscriber station, portable subscriber station, user It may also include all or part of the functionality of the device or the like.

The expressions used in the singular herein may be interpreted in the singular or the plural, unless an explicit expression such as “one” or “single” is used.

Embodiments of the present invention may be supported by standard documents related to 3rd Generation Partnership Project (3GPP) 5G systems, such as the Study on Architecture for Next Generation System (FS_NextGen). That is, steps or parts which are not described in order to clearly reveal the technical spirit of the present invention among the embodiments of the present invention may be supported by the document. In addition, all terms disclosed in the present document can be described by the above standard document.

1 illustrates a configuration of a distributed core system according to an embodiment of the present invention.

Referring to FIG. 1, a distributed core system includes a central node 100 located at a communication bureau and serving a control function, and a plurality of edge nodes 200 arranged forward in proximity to each base station site and serving bearer forwarding functions. Include.

Here, the central node 100 includes a central core device (control plane function, hereinafter referred to as 'CFP') 110 and a controller 130. The plurality of edge nodes 200 includes an edge core device (hereinafter, referred to as a “UPF”) 210 and a switch 230.

The CFP 110 includes various functions for controlling a network and a terminal, for example, signaling and authentication for call connection, service policy application, billing, session management, and mobility management. ). Finally, traffic transmission parameters to be used in the edge node 200 are finally determined in consideration of user services and network conditions such as bearer management and quality of service (QoS) management.

At this time, the access and mobility function (AMF) 111 in charge of the mobility management function of the terminal 600 and the session management function (SMF) 113 in charge of the session management function of the terminal 600 are independent functional units ( Function) may be included in the CFP unit 110.

The controller 130 communicates with the plurality of switches 230 using a specific protocol to dynamically set data transmission paths of the plurality of switches 230. The controller 130 creates, modifies, and deletes a flow entry defining a data transmission path through a flow command. A flow may refer to a packet flow of a specific path according to a combination of a series of packets or multiple flow entries of multiple switches that share a value of at least one header field from one switch perspective.

Here, the specific protocol may include a software defined network (hereinafter, referred to as SDN) protocol, an openflow protocol, and the like.

In particular, the controller 130 transmits a flow command generated based on the mobility information of the terminal 600 received from the CFP unit 110 to the switch 230 through the backhaul transmission network 300.

The UPF 210 processes the actual user data by applying the parameter determined by the CFP unit 110. For example, user data processing may include functions such as data transfer, data discard, data buffering, tunnel encapsulation and decapsulation, or the execution of quality of service (QoS) assurance.

The UPF 210 accesses the AMF 111 and the SMF 113 through the switch 230 and performs a signaling procedure for call connection and session creation. In this case, the switch 230 is connected to the AMF 111 and the SMF 113 through a signaling interface.

The switch 230 performs a flow relay operation under the control of the controller 130. That is, the switch 230 transmits data received from the Internet network 400 to the terminal 600 through the base station 500, and transmits data received from the terminal 600 through the base station 500 to the internet network 400. To pass).

At this time, the switch 230 transmits data according to the flow entry registered in the flow table. The switch 230 manages the flow table according to the flow command received from the controller 130, and creates, changes, and deletes the flow table. It also creates, changes, and deletes flow entries in the flow table.

The terminal 600 connects to the edge node 200. In this case, the terminal 600 accesses the central node 100 through the base station 500 and the switch 230 in which the edge node 200 is located in close proximity and performs a network access procedure. Here, the base station 500 may be a wireless signal processing apparatus equipped with a wireless processing function of the base station. The wireless signal processing apparatus is installed in a service target area, and amplifies an RF signal and transmits the amplified RF signal through an antenna. In this case, although not shown, a digital unit (hereinafter, referred to as “DU”) equipped with a digital signal processing function of the base station may be included in the central node 100.

The CPF 110 generates a session of the terminal 600 and generates a Tunnel Endpoint ID (TEID), which is an in-network identifier for the terminal 600. The CPF 110 delivers session information including the in-network identifier to the controller 130.

The controller 130 generates a flow rule according to the session information, and transmits a flow command including the flow rule to the switch 230 through the backhaul transmission network 300. Here, the flow rule is used to set the data transmission / reception path of the terminal 600 to the switch 230.

The switch 230 extracts a flow rule from the received flow command and generates a flow entry based on the flow rule. The flow entry includes a Match field and an Action field.

The match field is a field in which a flow rule for distinguishing the received data is recorded. The match field may include information included in each packet header, a packet incoming port number where the packet enters the switch, metadata, and the like. In other words, different fields can be configured and processed for each flow using the match field.

The action field contains contents defining what processing is to be performed when data meeting the conditions described in the match field is received.

According to an embodiment of the present invention, a flow rule that defines data processing consists of port information connecting the switch 230 and adjacent components 210, 300, 400, 500. The switch 230 includes four ports, a port connecting the switch 230 and the UPF 210, a port connecting the switch 230 and the backhaul transmission network 300, a switch 230 and the Internet network ( A port for connecting 400, and a port for connecting the switch 230 and the base station 500.

When the terminal 600 requests a handover by moving the base station site, the CPF 110 transmits handover request information to the controller 130 and requests mobility control of the terminal 600. In this case, the terminal mobility control operation of the controller 130 will be described in detail as follows.

2 is a view illustrating a state in which a terminal is connected to a serving edge core device before moving according to an embodiment of the present invention, and FIG. 3 is a diagram illustrating inter-handover between edge core devices due to movement of a terminal according to an embodiment of the present invention. 4 illustrates a state in which handover occurs, and FIG. 4 illustrates a state in which interhandover between edge core devices is completed according to an embodiment of the present invention.

First, referring to FIG. 2, the terminal 600 connects to the serving edge core device 211 at the first connection. Here, the first connection refers to an operation of first connecting to the network, such as powering on the terminal 600. In this case, the terminal 600 performs a network access procedure by accessing the central node 100 through the base station 501 and the first switch 231 in which the serving edge core device 211 is closely located.

When the network connection procedure is successfully completed, the first switch 231 receives a flow command from the controller 130. The flow entry shown in Table 1 is generated according to the flow rule extracted from the flow command.

Identification no Match Action Explanation No1. TEID = 100 & Incoming port = ① Output to port = ② Uplink: Base Station-> Core No2. TEID = 100 & Incoming port = ② Output to port = ③ Uplink: Core-> Internet No3. TEID = 100 & Incoming port = ③ Output to port = ② Downlink: Internet-> Core No4. TEID = 100 & Incoming port = ② Output to port = ① Downlink: Core-> Base Station

Here, the port of the first switch 231 is a port (①) connected to the base station 501, a port (②) connected to the first UPF, a port (③) connected to the Internet network 400, a backhaul transmission network ( And a port ④ connected to 300.

According to Table 1, when data of a specific subscriber (TEID = 100) flows into Incoming port = ①, it outputs to port = ②. That is, when data is received from the base station 501, the first switch 231 outputs the data to the first UPF 211.

When data of a specific subscriber (TEID = 100) flows into the incoming port = ②, it is output to port = ③. That is, when data is received from the first UPF 211, the first switch 231 outputs the data to the internet network 400.

When data of a specific subscriber (TEID = 100) flows into the incoming port = ③, it is output to port = ②. That is, when data is received from the base station 501, the first switch 231 outputs the data to the first UPF 211.

When data of a specific subscriber (TEID = 100) flows into Incoming port = ②, it outputs to port = ①. That is, when data is received from the base station 501, the first switch 231 outputs the data to the base station 501.

Therefore, the uplink data is transferred to the paths of the ports ① → ② → ③, and the downlink data is transferred to the paths of ③ → ② → ①.

When the terminal 600 moves and accesses the target base station 503, inter handover between edge core devices occurs as shown in FIG. 3. In particular, FIG. 3 illustrates a case where the terminal moves while downloading a large amount of data from the serving edge core device.

Referring to FIG. 3, when the terminal 600 moves and accesses the target base station 503, the handover request is transmitted to the CPF 110 through the second switch 233. The CPF 110 transmits the handover request information of the terminal 600 to the controller 130 and requests the mobility control of the terminal 600.

The controller 130 flows the serving edge core device 211 to the serving edge core device 211 so that the service provided from the serving edge core device 211 to the terminal 600 may proceed continuously to the terminal 600 through the target edge core device 213. Request a rule change and transmit a flow command to the target edge core device 213 to request the generation of the flow rule.

Table 2 shows the flow entry changed by the first switch 231 according to the flow command transmitted from the controller 130 to the serving edge core device 211.

Identification no Match Action Explanation No3. TEID = 100 & Incoming port = ③ Output to port = ④ Downlink: Internet → Serving Edge → Target Edge

In comparison with Table 1, according to the handover of the terminal 600, flow entries corresponding to No1, No2, and No4 were deleted, and flow entries corresponding to No3 were modified. That is, when data of a specific subscriber (TEID = 100) flows into the incoming port = ③, it outputs to port = ④. That is, when data is received from the internet network 400, the first switch 231 outputs the data to the second switch 233 of the target edge core device 213 through the backhaul transmission network 300.

Therefore, even if the terminal 600 moves while downloading a large amount of data from the serving edge core device 211, the target edge core device 213 directly through the backhaul transmission network 300 without passing through the first UPF 211. Since it can be downloaded, unnecessary traffic processing of the first UPF 211 does not occur.

In addition, the second switch 233 generates a flow entry shown in Table 3 according to the flow rule extracted from the flow command.

Identification no Match Action Explanation No1. TEID = 100 & Incoming port = ⓐ Outputtoport = ⓑ Uplink: Base Station-> Core No2. TEID = 100 & Incoming port = ⓑ Outputtoport = ⓒ Uplink: Core-> Internet No3. TEID = 100 & Incoming port = ⓒ Outputtoport = ⓑ Downlink: Internet-> Core No4. TEID = 100 & Incoming port = ⓓ Outputtoport = ⓑ Downlink: Internet → Serving Edge → Target Edge No5. TEID = 100 & Incoming port = ⓑ Outputtoport = ⓐ Downlink: Core-> Base Station

Here, the port of the second switch 233 is a port ⓐ connected to the base station 503, a port ⓑ connected to the first UPF, a port ⓒ connected to the Internet network 400, and a backhaul transmission network ( And a port ⓓ connected to 300.

According to Table 3, when data of a specific subscriber (TEID = 100) flows into Incoming port = ⓐ, it outputs as port = ⓑ. That is, when data is received from the base station 503, the second switch 233 outputs the data to the second UPF 213.

When data of a specific subscriber (TEID = 100) flows into Incoming port = ⓑ, it outputs to port = ⓒ. That is, when data is received from the second UPF 213, the second switch 233 outputs the data to the internet network 400.

When data of a specific subscriber (TEID = 100) flows into Incoming port = ⓒ, it outputs as port = ⓑ. That is, when data is received from the internet network 400, the second switch 233 outputs the data to the second UPF 213.

When data of a specific subscriber (TEID = 100) flows into Incoming port = ⓓ, it outputs to port = ⓑ. That is, when data is received from the first switch 231 through the backhaul transmission network 300, the second switch 233 outputs the data to the second UPF 213.

When data of a specific subscriber (TEID = 100) flows into Incoming port = ⓑ, it outputs as port = ⓐ. That is, when data is received from the second UPF 213, the second switch 233 outputs the data to the base station 503.

Thus, the uplink data is delivered on the path ⓐ → ⓑ → ⓒ and the downlink data is transferred on the path ⓒ → ⓑ → ⓐ or ⓓ → ⓑ → ⓐ. The second switch 233 processes the uplink data and the downlink data generated after the terminal 600 moves according to the flow entry of Table 2.

Here, the path of ⓓ → ⓑ → ⓐ corresponds to the data path received by the serving edge core device 211 before the terminal 600 moves. Therefore, transmission can be performed without loss of traffic due to handover.

Thereafter, when the handover of the terminal 600 is completed, the CPF 110 transmits handover completion information to the controller 130. The controller 130 changes the flow rules of the first switch 231 and the second switch 233 according to the handover completion information, and sends a flow command including the changed flow rule to the first switch 231 and the second switch. Transmit to 233, respectively.

Since the controller 130 completes the handover, the controller 130 generates a flow rule for deleting the flow entry of the terminal 600 set in the first switch 231. Accordingly, the first switch 231 deletes all of the flow entries shown in Table 2 according to the flow command received from the controller 130.

Since the handover is completed, the controller 130 generates a flow rule for deleting a flow entry defining a data processing rule transferred from the first switch 231 to the second switch 233. The second switch 233 modifies the flow entry as shown in Table 4 according to this flow rule.

Identification no Match Action Explanation No1. TEID = 100 & Incoming port = ⓐ Output to port = ⓑ Uplink: Base Station-> Core No2. TEID = 100 & Incoming port = ⓑ Output to port = ⓒ Uplink: Core-> Internet No3. TEID = 100 & Incoming port = ⓒ Output to port = ⓑ Downlink: Internet-> Core No5. TEID = 100 & Incoming port = ⓑ Output to port = ⓐ Downlink: Core-> Base Station

In comparison with Table 3, the flow entry corresponding to No4 is deleted according to the handover completion of the terminal 600. Therefore, the uplink data of the terminal 600 is transferred to the path of port ⓐ → ⓑ → ⓒ of the second switch 233, and the downlink data is transferred to the path of ⓒ → ⓑ → ⓐ of the second switch 233. do. As such, when the handover is completed, the data transmission path for service continuity is deleted, so that the terminal 600 first accesses the target edge core device 213 without changing the IP assigned to the terminal. The second UPF 213 is linked with a new anchoring point.

5 illustrates an organic connection flow diagram between components of a distributed core system according to an embodiment of the present invention. In this case, detailed descriptions that overlap with the contents described with reference to FIGS. 1 to 4 will be omitted.

Referring to FIG. 5, the terminal 600 transmits an attach request, which is a non-access stratum (NAS) message, to the CPF 110 for initial access (S101 and S103). The access request may include International Mobile Station Identity (IMSI) information of the terminal 600.

The CPF 110 performs an authentication procedure such as subscriber authentication for the terminal 600, a subscriber registration in the network, a check of which service a user can use, and location registration (S105).

The CPF 110 assigns a terminal endpoint identifier (TEID), which is an IP address of the terminal 600 and an ID of a bearer, respectively (S107 and S109) to generate a session (S111). In operation S113, an access response message is transmitted to the first switch 231.

The first switch 231 transfers the access response message to the first UPF 211 (S115). The first switch 231 transfers the access response message to the terminal 600 (S117).

The CPF 110 transmits session information including the TEID to the controller 130 (S119).

The controller 130 generates a flow rule for the TEID (S121), and transmits a flow command including the generated flow rule to the first switch 231 (S123).

The first switch 231 generates a flow entry based on the flow rule extracted from the received flow command (S123) (S125). Data processing is performed based on the generated flow entry (S127).

6 is a flowchart illustrating an organic connection between components of a distributed core system when a handover occurs according to an embodiment of the present invention.

Referring to FIG. 6, when the terminal 600 generates a handover from the serving base station 501 to the target base station 503 (S201), the terminal 600 sends a CPF 110 to the CPF 110 through the first switch 231. The handover request is transmitted (S203, S205).

The CPF 110 transmits the handover request information to the controller 130 (S207). The controller 130 changes the flow rule of the serving edge core device 211 according to the handover request information (S209). In operation S211, a flow command including the changed flow rule is transmitted to the first switch 231.

The controller 130 generates a flow rule of the target edge core device 213 according to the handover request information (S213). In operation S215, a flow command including the generated flow rule is transmitted to the second switch 233.

The first switch 231 changes the pre-generated flow entry based on the flow rule extracted from the received flow command (S211) (S217), and then processes data based on the changed flow entry (S219).

The second switch 233 generates a flow entry based on the flow rule extracted from the received flow command (S 215), and then processes data based on the generated flow entry (S 223).

At this time, Based on the changed flow entry (S217) and the generated flow entry (S221), data for service continuation is transmitted from the first switch 231 to the terminal 600 through the second switch 233.

7 is a flowchart illustrating an organic connection between components of a distributed core system when handover is completed according to an embodiment of the present invention.

Referring to FIG. 7, when the handover procedure of the terminal 600 is completed, the CPF 110 transmits handover completion information to the controller 130 (S301).

The controller 130 performs a flow rule change of each of the first switch 231 and the second switch 233 according to the handover completion information (S303). Then, the flow command including the changed flow rules is transmitted to the first switch 231 and the second switch 233, respectively (S305 and S307).

The first switch 231 changes the flow entry (S309) based on the flow rule extracted from the received flow command (S305). In this case, the change corresponds to the deletion of the flow entry of the terminal 600.

The second switch 233 changes the flow entry based on the flow rule extracted from the received flow command (S307) (S311). Data is processed based on the changed flow entry (S311) (S313).

8 is a hardware block diagram of a server device according to an embodiment of the present invention, and the central node 100, the edge node 200, the CPF 110, the AMF 111, and the SMF described with reference to FIGS. 1 to 7 are illustrated. Hardware configuration of the 113, the controller 130, the UPF 210, the switch 230, the first UPF 211, the first switch 231, the second UPF 213, and the second switch 233. Indicates.

Referring to FIG. 8, the server device 700 includes a communication device 701, a memory 703, a storage device 705, and at least one processor 707. The communication device 701 is connected with at least one processor 707 to transmit and / or receive data via the networks 300 and 400. The memory 703 is connected to at least one processor 707 and stores a program including instructions for executing the configuration and / or method according to the embodiments described with reference to FIGS. 1 to 7. The program implements the present invention in combination with hardware such as memory 703 and at least one processor 707.

The storage device 705 includes information necessary for the operation of the server device. The processor 707 executes the present invention in combination with hardware such as the memory 703, the storage device 705, and the like.

The embodiments of the present invention described above are not only implemented through the apparatus and the method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (15)

In a distributed core system including a central core device for managing mobility and a plurality of edge core devices for processing data according to the control of the central core device, a controller connected to the central core device to control the mobility of the terminal,
Receiving mobility information of the terminal from the central core device;
Identifying a serving switch connected to a serving edge core device of the terminal and a target switch connected to a target edge core device of the terminal based on the mobility information;
Transmitting a changed flow rule to the serving switch, and
Transmitting the newly generated flow rule to the target switch,
The changed flow rule is set such that the serving switch transmits data of the terminal to the target switch through a backhaul transmission network, and the newly generated flow rule transmits data of the terminal received from the serving switch to the target edge core device. And to transmit to the terminal after being processed by the. In claim 1,
The newly created flow rule,
And a flow entry configured to deliver downlink data received through the Internet network and uplink data received from the terminal after being processed by the target edge core device.
After transmitting the newly generated flow rule,
Receiving handover completion information of the terminal from the central core apparatus;
Transmitting a flow rule to the serving switch requesting deletion of a flow entry set to be delivered to the target switch, and
Transmitting a flow rule to the target switch requesting deletion of a flow entry for data received from the serving switch;
Further comprising, mobility control method. In claim 2,
Before the step of receiving the handover request information,
Receiving network connection information of the terminal from the central core apparatus, and
Transmitting the newly generated flow rule to the serving switch;
The newly generated flow rule transmitted to the serving switch includes a flow entry configured to transmit downlink data received through an internet network and uplink data received from a terminal after being processed by the serving edge core device. Control method. In claim 3,
The flow entry,
A match field in which the terminal sets an in-network identifier allocated from the central core device and a data inflow port into which the data is introduced; and
An action field defining a port for outputting data introduced to the data inflow port;
The in-network identifier is
The central core device is assigned when assigning an IP address to the terminal and included in the data of the terminal and used to identify the subscriber. In claim 1,
The controller and the switch,
A method of mobility control that communicates via Software Defined Networks (SDN) protocol. In a distributed core system including a central core device that manages mobility and a plurality of edge core devices that process data according to the control of the central core device, a serving switch connected to a serving edge core device controls the mobility of a terminal. ,
Receiving a changed flow rule according to a handover request of the terminal from a controller connected to the central core device, and
Transmitting downlink data of the terminal to the target switch through a backhaul transmission network according to the changed flow rule;
Downlink data of the terminal,
And from the target switch to a target edge core device connected to the target switch, to be processed by the target edge core device and to the terminal. In claim 6,
The changed flow rule,
And a flow entry in which a port connected between the serving switch and the internet network is set as a data inflow port and a port connected between the serving switch and the backhaul transport network is set as a data output port. In claim 6,
After transferring to the target switch,
Receiving a changed flow rule according to the handover completion of the terminal from the controller, and
Deleting all of the flow entries of the terminal according to the changed flow rule
Further comprising, mobility control method. In claim 6,
Before the step of receiving the flow rule,
Receiving a flow rule according to a network connection of the terminal from the controller, and
Processing uplink data of the terminal and downlink data of the terminal according to a flow rule according to the network connection;
The flow rule according to the network connection,
And configured to transmit the uplink data of the terminal and the downlink data of the terminal to the terminal after being processed by the serving edge core device. In claim 9,
The flow rule according to the network connection,
A flow entry in which a port connected between the serving switch and the internet network is set as a data inflow port and a port connected between the serving switch and the serving edge core device is set as a data output port;
A flow entry in which a port connected between the serving switch and the serving edge core device is set as the data inflow port and a port connected between the serving switch and a base station to which the terminal is connected as a data output port;
A flow entry having a port connected between the base station and the serving switch as a data inflow port and a port connected between the serving switch and the serving edge core device as a data output port; and
A flow entry in which a port connected between the serving switch and the serving edge core device is set as the data inflow port and a port connected between the serving switch and the internet network as a data output port.
Including a mobility control method. In a distributed core system including a central core device that manages mobility and a plurality of edge core devices that process data according to control of the central core device, a target switch connected to a target edge core device controls the mobility of a terminal. ,
Receiving a flow rule generated according to a handover request of the terminal from a controller connected to the central core device;
Receiving, by the serving switch, data in service to the terminal from the serving switch according to the flow rule; and
Processing data received from the serving switch according to the flow rule;
The flow rule is configured to transmit data received from the serving switch to the terminal after being processed by the target edge core device. In claim 11,
After the transmitting step,
Receiving a flow rule changed according to the handover completion of the terminal from the controller, and
Deleting a flow entry for data received from the serving switch according to the changed flow rule
Further comprising, mobility control method. In claim 12,
After receiving the changed flow rule,
Processing uplink data of the terminal and downlink data of the terminal according to the changed flow rule;
The changed flow rule,
Mobility, wherein the uplink data of the terminal is processed by the target edge core device and then transferred to the internet network, and the downlink data of the terminal is processed by the target edge core device and then transferred to the terminal. Control method. In claim 13,
The generated flow rule and the changed flow rule,
The in-network identifier of the data is set equally,
The in-network identifier is
The mobility control method is given when the IP address of the terminal is assigned. In claim 11,
The serving switch and the target switch are connected through a backhaul transmission network,
The flow rule,
It is set as the relationship information between the data inlet port and the data output port.
The data inflow port and the data output port,
A first port connected between the target switch and the backhaul transmission network;
A second port connected between the target switch and the internet network;
A third port connected between the target switch and the target edge core device, and
And a fourth port connected between the target switch and the base station.

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