KR101767472B1 - Method for changing data path by sdn-based controller - Google Patents

Abstract

The present invention relates to a network capable of efficient and proper handover or load balancing by utilizing a SDN (Software Defined Network) in an environment where heterogeneous interface networks are mixed, and a central controller It is possible to manage the handover in an efficient and satisfactory manner.

Description

METHOD FOR CHANGING DATA PATH BY SDN-BASED CONTROLLER [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network capable of efficient and proper handover or load balancing by utilizing SDN (Software Defined Network) in a mixed environment of heterogeneous interface networks.

Handover in heterogeneous wireless networks is not performed in real time, and APs with weak radio signals of WiFi AP or interference between APs tend to be selected.

1. OpenFlow Switch Specification version 1.4.0 (Wire Protocol 0x05), October 14, 2013 [https://www.opennetworking.org/images/stories/downloads/sdn-resources/onf-specifications/openflow/openflow-spec- v1.4.0.pdf] 2. Software-Defined Networking: The New Norm for Netwrks, ONF White Paper, April 13, 2012 [https://www.opennetworking.org/images/stories/downloads/sdn-resources/white-papers/wp-sdn- newnorm.pdf] 3. ETSI GS NFV 002 v1.1.1 (2013-10) [http://www.etsi.org/deliver/etsi_gs/NFV/001_099/002/01.01.01_60/gs_NFV002v010101p.pdf]

It is an object of the present invention to provide an SDN-based controller and / or a switch, or a network system including the same, capable of instructing a mobile terminal to perform handover based on centralized access network information or the like using an SDN .

A network system capable of changing the heterogeneous network path of traffic according to an embodiment of the present invention includes a SDN (Software Defined Network) agent, and a first and a second wireless network interface A mobile terminal having two communication modules; An SDN-based first and second wireless access devices that wirelessly communicate with the first and second communication modules, respectively; An SDN based switch for performing wired or wireless communication with the first and second wireless access devices and switching traffic between the mobile terminal and the external network through the first and second wireless access devices; And an SDN-based controller for transmitting a network change message for changing from the first wireless access device to the second wireless access device to relay the communication between the mobile terminal and the SDN switch to the SDN switch.

In addition, when the SDN controller makes a network change decision by at least one of a network state, a QoS policy, a setting request by the user of the mobile terminal, and a setting instruction by the SDN controller administrator, the SDN controller generates the network change message .

In addition, when the mobile terminal receives the network change message through the first wireless access device, the mobile terminal can activate the second communication module and communicate with the second wireless access device.

Also, the mobile terminal may transmit the IP address request message of the second communication module to the second wireless access device.

The IP address request message may include a network change notification indicating that the first communication module is in communication.

The SDN switch transmits the IP address request message to the SDN controller when the network change notification is included in the IP address request message of the mobile terminal received through the second radio access device, The address request message may include identification information of the second communication module.

If the SDN controller does not have the identification information of the second communication module of the mobile terminal, the SDN controller transmits the IP address of the first communication module and the IP address of the second communication module via the SDN switch before transmitting the network change message. The mobile terminal network information including the identification information can be acquired.

When the SDN controller receives the IP address request message for the second communication module including the identification information of the second communication module of the mobile terminal after transmitting the network change message, The second communication module network configuration information including the same IP address as the IP address of the first communication module can be generated.

The second communication module network configuration information may be transmitted to the second communication module of the mobile terminal through the second wireless access device.

In addition, the mobile terminal network information and the second communication module network configuration information may include at least one of the same default gateway information, a subnet mask, and DNS (Domain Name Server) information.

In addition, one of the first and second wireless networks may be a mobile communication and the other may be a WiFi network.

Also, the second wireless network may be WiFi, and the network change message may include SSID information required for connection to the second wireless access device.

The network change message may further include a wireless encryption key required for encrypted communication with the second wireless access device.

In addition, the network change message may include a command to allow the mobile terminal to access the second wireless access device specified by the controller among a plurality of wireless access devices of the same type as the second wireless access device.

A network interface changing method according to another embodiment of the present invention includes a SDN-based switch controlled by a SDN (Software Defined Network) -based controller, a first and second radio access devices A method of changing a network interface of an SDN-based mobile terminal having first and second communication modules of different kinds of network interfaces communicating with each other through a first communication module, step; Receiving a network change message from the SDN controller; And activating the second communication module in response to the network change message.

Receiving a message requesting network information of the mobile terminal before receiving the network change message; And generating the mobile terminal network information including the IP address of the first communication module and the identification information of the second communication module, and transmitting the generated mobile terminal network information to the first wireless access device.

Transmitting an IP address request message to the second wireless access device when the second communication module is activated; And receiving the second communication module network configuration information including the same IP address as the IP address of the first communication module in response to the IP address request message.

In addition, the second communication module network setting information may include at least one of default gateway information, a subnet mask, and DNS (Domain Name Server) information, and at least one of the second communication module network setting information may include at least one of May be the same as at least one of the network information.

Also, the second wireless network is a WiFi network, and the network change message includes at least SSID information among SSID information necessary for connection to the second wireless access device and wireless encryption key required for encrypted communication with the second wireless access device .

The data path method according to another exemplary embodiment of the present invention includes an SDN-based mobile terminal having first and second communication modules of different types of network interfaces, first and second wireless accesses based on SDN (Software Defined Network) A method for changing a data path of an SDN-based controller for controlling an SDN-based switch communicating via a first wireless access device, wherein a data path between the mobile terminal and the SDN switch via the first wireless access device, Determining a network change to cause the device to pass; And generating a network change message corresponding to the network change.

In addition, the network change determination may be determined by at least one of a network state, a QoS policy, a setup request by the user of the mobile terminal, and a setup instruction by the SDN controller administrator.

Also, if there is no identification information of the second communication module, before determining the network change, mobile terminal network information including the IP address of the first communication module and the identification information of the second communication module is transmitted through the SDN switch And a step of acquiring the image data.

Transmitting the generated network change message to the SDN switch and receiving an IP address request message for the second communication module of the mobile terminal; And generating second communication module network configuration information including the same IP address as the IP address of the first communication module from the mobile terminal network information.

In addition, the mobile terminal network information and the second communication module network configuration information may include at least one of the same default gateway information, a subnet mask, and DNS (Domain Name Server) information.

The second communication module network configuration information may be transmitted to the second communication module of the mobile terminal through the second wireless access device.

A computer program according to another embodiment of the present invention may include computer executable instructions for performing the above-mentioned methods.

According to the present invention, it is possible to manage the handover in a central controller capable of grasping the entire network state rather than the mobile terminal, thereby providing an efficient and satisfactory handover.

1 is a block diagram of an SDN network system according to an embodiment of the present invention;
2 is a block diagram of a controller of the network system of FIG. 1;
FIG. 3 is a block diagram of a switch of the network system of FIG. 1,
4 is an operation table showing a field table of a flow entry and an operation type according to a flow entry,
5 shows the field table of the group and meter tables,
6 is a block diagram of a network system according to an embodiment of the present invention;
7 is a block diagram of a network system according to another embodiment of the present invention, and Fig.
8 is a signal flow diagram in the network system of Fig. 7 of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Also, the fact that the first component and the second component on the network are connected or connected means that data can be exchanged between the first component and the second component by wire or wirelessly.

In addition, suffixes "module" and " part "for the components used in the following description are given merely for convenience of description, and do not give special significance or role in themselves. Accordingly, the terms "module" and "part" may be used interchangeably.

When such components are implemented in practical applications, two or more components may be combined into one component, or one component may be divided into two or more components as necessary. The same or similar elements are given the same throughout the drawings, and the detailed description of the elements having the same reference numerals can be omitted and replaced with the description of the above-described elements.

FIG. 1 is a block diagram of an SDN network system according to an embodiment of the present invention. FIG. 2 is a block diagram of a controller of the network system of FIG. 1. FIG. 3 is a block diagram of a switch of a network system of FIG. 4 is an operation table showing a field table of a flow entry and an operation type according to a flow entry, and Fig. 5 is a field table of a group and a meter table.

Referring to FIG. 1, an SDN network system according to an embodiment of the present invention may include a controller 10, a plurality of switches 20, and a plurality of network devices 30.

The network device 30 may include a user terminal device for exchanging data or information, or a physical device or a virtual device for performing a specific function. From a hardware standpoint, the network device 30 may be a PC, a client terminal, a server, a workstation, a supercomputer, a mobile communication terminal, a smart phone, a smart pad, or the like. The network device 30 may also be a virtual machine (VM) created on a physical device.

The network device 30 may be referred to as a network function that performs functions on various networks. Network features include anti-DDoS, intrusion detection / blocking (IDS / IPS), integrated security services, virtual private network services, anti-virus, anti-spam, security services, access management services, firewalls, load balancing, . ≪ / RTI > These network functions can be virtualized.

There is a network function virtualization (NFV) defined in a white paper on NFV issued by the European Telecommunications Standards Institute (ETSI) (see non-patent reference 3) as a virtualized network function. The network function (NF) may be used herein in combination with network function virtualization (NFV). NFV provides necessary network functions by dynamically generating necessary L4-7 service connection for each tenant, and provides firewall, IPS and DPI functions necessary for policy-based DDoS attacks quickly through a series of service chaining . NFVs can also easily turn on and off firewalls or IDS / IPS and provision them automatically. NFV can also reduce the need for overprovisioning.

A controller 10 is a kind of command computer that controls the SDN system and can perform various complex functions such as routing, policy declaration, and security check. The controller 10 can define the flow of packets occurring in the plurality of switches 20 in the lower layer. The controller 10 may calculate a path (data path) to be flowed by referring to a network topology or the like with respect to a flow allowed in the network policy, and then set an entry of the flow on a switch on the path. The controller 10 may communicate with the switch 20 using a specific protocol, e.g., an open flow protocol. The communication channel between the controller 10 and the switch 20 can be encrypted by SSL.

2, the controller 10 may include a switch communication unit 110, a control unit 100, and a storage unit 190, which communicate with the switch 20.

The storage unit 190 may store a program for processing and controlling the control unit 100. [ The storage unit 190 may perform a function for temporarily storing input or output data (packet, message, etc.). The storage unit 190 may include an entry database (DB) 191 for storing flow entries.

The controller 100 may control the overall operation of the controller 10 by controlling the operations of the respective units. The control unit 100 may include a topology management module 120, a path calculation module 125, an entry management module 135, and a message management module 130. Each module may be configured in hardware in the control unit 100 and may be configured in software separate from the control unit 100. [

The topology management module 120 can construct and manage network topology information based on the connection relationship of the switches 20 collected through the switch communication unit 110. [ The network topology information may include a topology between the switches and a network device topology connected to each switch.

The path calculation module 125 can obtain the data path of the packet received through the switch communication unit 110 and the action column to be executed by the switch on the data path based on the network topology information established in the topology management module 120 .

The entry management module 135 registers the entry in the entry DB 191 as an entry such as a flow table, a group table, and a meter table based on the result calculated by the route calculation module 125, a policy such as QoS, . The entry management module 135 may proactively register an entry in each table in the switch 20 and react to an addition or update request of an entry from the switch 20. [ The entry management module 135 may change or delete entries in the entry DB 191 as needed or in accordance with an entry disappearance message of the switch 10. [

The message management module 130 may interpret a message received through the switch communication unit 110 or may generate a controller-switch message to be transmitted to the switch through the switch communication unit 110, which will be described later. The status change message, which is one of the controller-switch messages, may be generated based on the entry according to the entry management module 135 or the entry stored in the entry DB 191. [

The switch 20 may be a physical switch or a virtual switch supporting an open flow protocol. The switch 20 can process the received packet and relay the flow between the network devices 30. [ To this end, the switch 20 may comprise a single flow table or a multiple flow table for pipeline processing as described in non-patent document 1. [

The flow table may include a flow entry defining rules for how to handle the flow of network device 30. [

A flow may refer to a packet flow of a particular path according to a series of packets sharing a value of at least one header field from a single switch or a combination of multiple flow entries of multiple switches. The open-flow network can perform path control, fault recovery, load balancing and optimization on a flow-by-flow basis.

The switch 20 can be divided into a core switch between an ingress and egress edge switch and an edge switch between a flow according to the combination of multiple switches.

3, the switch 20 includes a port portion 205 for communicating with other switches and / or network devices, a controller communication portion 210 for communicating with the controller 10, a switch control portion 200, and a storage portion 290).

The port unit 205 may include a plurality of pairs of ports that are flown out from a switch or a network device. A pair of ports can be implemented as one port.

The storage unit 290 may store a program for processing and controlling the switch control unit 210. [ The storage unit 290 may perform a function for temporarily storing input or output data (packets, messages, etc.). The storage unit 290 may include a table 291 such as a flow table, a group table, and a meter table. Entries in the table 230 or table may be added, modified, or deleted by the controller 10. The table entry can be destroyed by itself.

The flow table can be composed of multiple flow tables to handle the pipeline of open flows. 4, a flow entry of a flow table includes match fields describing conditions (matching rules) to match a packet, a priority, counters to be updated when there are packets to be matched, An instruction that is a set of various actions that occurs when there is a packet matched to a flow entry, timeouts that describe the time to be discarded in the switch, and an opaque type that is selected by the controller. Can be used to filter flow statistics, flow changes, and flow deletions, and can include tuples such as cookies that are not used in packet processing. An instruction may change pipeline processing such as forwarding a packet to another flow table. The instructions may also include a collection of actions to add an action to an action set, or a list of actions to apply directly to a packet. An action is an operation that modifies a packet, such as sending a packet to a specific port or decreasing the TTL field. The action may be part of an instruction set associated with the flow entry or belonging to an action bucket associated with the group entry. An action set is an aggregated set of actions indicated in each table. An action set can be performed when no table is matched. 5 illustrates various packet processing by a flow entry.

A pipeline is a sequence of packets between a packet and a flow table. When a packet is input to the switch 20, the switch 20 searches for a flow entry matching the packet in the order of higher priority of the first flow table. When the matching is performed, the instruction of the entry is executed. An instruction may be an apply-action that is immediately matched, a command to clear or add / modify an action set, a write-action, a write-metadata command, And a goto-table that moves packets along with metadata to a table. If there is no flow entry matched with the packet, the packet may be dropped according to the table setting, or the packet may be sent to the controller 10 in a packet-in message.

The group table may include group entries. The group table may be indicated by a flow entry to suggest additional forwarding methods. Referring to FIG. 6, the group entry of the group table may include the following fields. A group identifier for identifying a group entry, a group type for specifying a rule for performing a select or all action buckets defined in the group entry, a counter for a flow entry , And action buckets, which are a set of actions associated with the parameters defined for the group.

The meter table is made up of meter entries and defines per-flow meters. The flow meter-party can allow open flows to be applied to various QoS operations. A meter is a kind of switch element that can measure and control the rate of packets. Referring to FIG. 7, a meter table includes a meter identifier identifying the meter, a rate specified in the band and meter bands indicating how the packet is to be operated, And counters fields that are updated when they become available. Meter bands include a band type indicating how the packet is to be processed, a rate used to select the meter band by the meter, counters that are updated when the packets are processed by the meter band, ), And a type specific argument, which is a bad type with optional arguments.

The switch control unit 210 can control the overall operation of the switch 200 by controlling the operations of the respective units. The control unit 210 may include a table management module 240 that manages the table 291, a flow search module 220, a flow processing module 230, and a packet processing module 235. Each module may be configured in hardware in the control unit 110 and may be configured in software separate from the control unit 110. [

The table management module 240 may add the entry received from the controller 10 to the appropriate table through the controller communication unit 210 or periodically remove the time-out entry.

The flow search module 220 may extract flow information from the received packet as user traffic. The flow information includes identification information of an ingress port as a packet inflow port of the edge switch, identification information of an incoming port of the switch of the switch, packet header information (IP address of the source and destination, MAC address, port, And VLAN information, etc.), metadata, and the like. The metadata may be optionally added in the previous table or may be data added in another switch. The flow search module 220 can search the table 291 for a flow entry for a received packet by referring to the extracted flow information. The flow search module 220 may request the flow processing module 260 to process the received packet according to the retrieved flow entry, if a flow entry is found. If the flow entry search fails, the flow search module 220 may transmit the minimum data of the received packet or the received packet to the controller 100 through the controller communication unit 210.

The flow processing module 230 may process an action, such as outputting a packet to a specific port or multiple ports, dropping it, or modifying a specific header field, in accordance with the procedure described in the entry retrieved from the flow search module 220 have.

The flow processing module 230 may execute an action set to execute a pipeline process of a flow entry, execute an instruction to change an action, or execute a set of actions when it is no longer possible to go to the next table in a multi-flow table.

The packet processing module 235 can actually output the processed packet by the flow processing module 230 to one or more ports of the port unit 205 specified by the flow processing module 230. [

Although not shown in FIG. 1, the SDN network system may further include an orchestrator for creating, changing, and deleting virtual network devices, virtual switches, and the like. When an orchestrator creates a virtual network device, the orchestrator generates a virtual network device such as a network device, such as identification information of a switch to be connected to the virtual network, port identification information connected to the switch, MAC address, IP address, tenant identification information, To the controller (10).

The controller 10 and the switch 20 exchange various information, which is called an open flow protocol message. Such an open flow message may be of a type such as a controller-to-switch message, an asynchronous message, and a symmetric message. Each message may have a transaction identifier (transaction id; xid) in the header that identifies the entry.

The controller-switch message is a message generated by the controller 10 and transmitted to the switch 20, which is mainly used for managing or checking the state of the switch 20. [ The controller-switch message may be generated by the controller 100 of the controller 10, and in particular by the message management module 130.

The controller-switch message includes features inquiring about the capabilities of the switch, configuration for inquiring and setting the settings of the configuration parameters of the switch 20, flow / group / meter of the open flow table, A modify state message for adding / deleting / modifying entries, a packet-out message for transmitting a packet received from the switch through a packet-in message to a specific port on the switch, and the like . The state change message includes a modify flow table message, a modify flow entry message, a modify group entry message, a prot modification message, and a meter entry change message. Message (meter modification message).

The asynchronous message is a message generated by the switch 20, and is used to update the state of the switch, the network event, and the like in the controller 10. The asynchronous message may be generated by the control unit 200 of the switch 20, in particular by the flow search module 220.

Asynchronous messages include packet-in messages, flow-removed messages, and error messages. The packet-in message is used by the switch 20 to send a packet to the controller 10 to receive control of the packet. The packet-in message includes all or part of the received packet, or a copy thereof, sent from the open flow switch 20 to the controller 10 to request the data path when the switch 20 receives an unknown packet Message. A packet-in message is used even when the action of the entry associated with the incoming packet is determined to be sent to the controller. The deleted flow-removed message is used to forward the flow entry information to the controller 10 to be deleted from the flow table. This message occurs when the controller 10 requests the switch 20 to delete the corresponding flow entry or in a flow expiry process by a flow timeout.

The symmetric message is generated in both the controller 10 and the switch 20, and is transmitted even when there is no request from the other party. A hello used to initiate the connection between the controller and the switch, an echo to confirm that there is no abnormality in the connection between the controller and the switch, and an error message used by the controller or switch to inform the other side of the problem an error message, and the like. The error message is mostly used in the switch to indicate a failure in response to a request initiated by the controller.

FIG. 6 is a block diagram of a network system according to an embodiment of the present invention. FIG. 7 is a block diagram of a network system according to another embodiment of the present invention. FIG. Please refer to Figs. 1 to 5.

Referring to FIG. 6, the mobile network system includes a mobile terminal 30, first and second radio access networks 40-1 and 40-2, a core network 60 based on a SDN (Software Defined Network) Based controller 10, as shown in FIG. Reference is made to Figs. 1 to 5 for a detailed description of the same or similar components.

The mobile terminal 30 may correspond to the network device of Fig. The mobile terminal 30 is preferably a mobile communication terminal capable of wireless transmission / reception, a smart phone, a mobile communication module, or a PC with a wireless communication module, a notebook, a smart pad, and the like.

The mobile terminal 30 may include a plurality of communication modules 31 and 32. The first and second communication modules 31 and 32 may be different types of network interfaces. In this embodiment, the network interface is preferably a wireless interface.

The mobile terminal 30 may include an SDN agent or be SDN-based. The SDN agent may include functionality to interpret and / or generate SDN-based messages (e.g., Open Flow Protocol messages). The SDN agent can be mounted on an OS or a part of the kernel or an application.

The radio access network may comprise a plurality of networks 40-1 and 40-2. Each of the wireless access networks 40-1 and 40-2 may have different kinds of wireless network protocols or interfaces.

The mobile network system may include first and second radio access devices (base stations) 41 and 42. Each base station 41 and 42 may be any device configured to access one or more communication networks, such as the core network 65 or the external network 60, via at least one mobile terminal 30 and an air interface. For example, the base stations 41 and 42 may include a base transceiver station (BTS), a node B, an eNode B, a home Node B, a home eNode B, a site controller, an access point (AP) Router or the like. Although each base station 41, 42 is shown as a single element in this embodiment, the base station may comprise any number of interconnected base stations and / or network elements.

The first radio access network 40-1 may be a base station itself or may include other base stations and / or network elements such as a base station controller (BSC), a radio network controller (RNC), a relay node, can do. The first base station 41 may be configured to transmit and receive radio signals within a specific area referred to as a cell. The cell may be subdivided into a plurality of cell sectors.

The mobile network system may be a multiple access system and may employ one or more channel approaches such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base stations 41 and / or 42 in the radio access network and the mobile terminal 30 may be connected to a Universal Mobile Telecommunications System (UMTS) terrestrial radio access (UTRA), which establishes a radio interface using wideband CDMA (WCDMA) The same wireless technology can be implemented. WCDMA may include communications protocols such as High Speed Packet Access (HSPA) or Evolved HSPA (HSPA +). The HSPA may include high speed downlink packet access (HSDPA) or high speed uplink packet access (HSUPA). In another embodiment, the base station 41 and / or 42 and the mobile terminal 30 may use an evolutionary UMTS terrestrial radio access (LTE) system that establishes a wireless interface using Long Term Evolution (LTE) and / or LTE- (E-UTRA). ≪ / RTI >

In other embodiments, the base stations 41 and / or 42 and the mobile terminal 30 may be configured to support IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access), CDMA2000, CDMA2000 1X, CDMA2000 EV- (GSM), EDGE (Enhanced Data Rates for GSM Evolution), GSM EDGE (GERAN), and the like, for example, IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 Can be implemented.

The base station 41 and / or 42 may be a wireless router, a home Node B, a home eNode B, or an AP and may be any suitable wireless access capable of wireless connection in a local area such as a business premises, home, automobile, campus, Network. In one embodiment, base station 40 and mobile terminal 30 may implement a wireless technology such as IEEE 802.11 (WiFi) to establish a wireless local area network (WLAN). In another embodiment, the base station 41 and / or 42 and the mobile terminal 30 may implement a wireless technology such as IEEE 802.15 to establish a wireless private network (WPAN). In another embodiment, the base station 40 and the mobile terminal 30 establish a picocell or femtocell using a cellular based wireless access network (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, can do.

The base station 41 and / or 42 may mount an SDN agent. The base stations 41 and / or 42 may communicate with the SDN-based switch 20 and / or the controller 10 of the core network 65. This communication protocol may follow, but is not limited to, the openflow protocol. The base station 40 may have the functions or components of the switches of Figs. 1 and 3, or may have additional functions or elements.

The wireless access network communicates with a core network 65 and the core network provides voice over one or more mobile terminals 30 with voice, data, applications and / or voice over internet protocol Lt; / RTI > network. For example, the core network can provide call control, billing services, mobile location-based services, prepaid calling, internet access, image distribution, and can perform advanced security functions such as user authentication. Although not shown in FIG. 6, the radio access network can directly or indirectly communicate with another radio access network using the same radio access network or another radio access network as the radio access network or the core network. For example, in addition to being connected to a wireless access network using E-UTRA wireless technology, the core network may also communicate with other wireless access networks (not shown) using GSM wireless technology.

The core network 65 may function as a gateway for the mobile terminal 30 to connect to the PSTN, the Internet, and the external network 60. [ The PSTN may include a circuit switched telephone network providing a plain old telephone service (POTS). The external network 60 may comprise a wired or wireless communication network owned or operated by another service provider. The external network 60 may include an Internet Service Provider (ISP), another core network, and a public data network (Internet).

In the present embodiment, the core network 65 may include an open flow switch 20 that satisfies the SDN-based open flow protocol. For details of the open flow switch 20, refer to FIG. 1 or FIG.

When the wireless access network uses an LTE system including an Evolved Universal Terrestrial Radio Access Network (EUTRAN), the open flow switch 20 can be switched between the serving gateway S-GW and the packet data network PDN gateway P- Or at least some of the functions of each gateway. The open flow switch 20 may be composed of two switches, serving gateway and PDN gateway functions. The base station may be referred to as eNode B (eNB) in the LTE system.

The controller 10 communicates with the SDN-based or SDN agent-mounted component and can control the component. In this embodiment, the controller 10 can communicate with the open flow switch 20 of the core network in an open flow protocol. The detailed description of the controller 10 is replaced by the contents of FIG. 1 and FIG.

Hereinafter, the first wireless access network 40-1 and the second wireless access network 40-2 among the various wireless interfaces use the LTE system and the WiFi system, respectively.

7, the mobile network system may include a mobile terminal 30, an eNode B (eNB) 41, an AP 42, a switch 20, a controller 10, and a core network 65 have. Each element may be SDN-based or may include an SDN agent.

The first communication module 31 of the mobile terminal 30 of FIG. 6 is connected to the LTE module 31, the second communication module 32 is connected to the WiFi module 32 and the first radio access device 41 is connected to the eNB 41, and the second wireless access device 42 may be configured as an AP 42. [ The LTE radio access network 40-1 and the WiFi radio access network 40-2 may correspond to the first and second radio access networks 40-1 and 40-2 of FIG.

The switch 20 is supposed to be disposed outside the core network 65, but is not limited thereto. For example, the switch 20 may be part of the core network 65 as described in FIG. The core network 65 may include the core network of the LTE system as it is. The core network 65 may include an Internet Service Provider (ISP) and / or a Dynamic Host Configuration Protocol (DHCP) server. In this embodiment, the external network may be a public data network such as the Internet.

The AP 42 may be directly connected to the external Internet. Or the AP 42 may be directly connected to the external Internet through the core network 65. [ The AP 42 can communicate indirectly with the switch 20 via the external network 60. [ As shown, the AP 42 and the switch 20 may communicate directly.

Hereinafter, the mobile terminal 30 is initially connected via the LTE air interface with reference to FIGS. 7 and 8. FIG.

When the mobile terminal 30 accesses the LTE radio access network (femtocell), the LTE module 31 can request an IP address to the eNB 41 (S410). The mobile terminal 30 may generate an IP address request message or may generate an IP address request message without the content, indicating that the mobile terminal 30 has not been connected to another wireless network at the beginning of the connection of the wireless network. The mobile terminal 30 may include a network change notification in the IP address request message indicating that the mobile terminal 30 is connected to another wireless network through another wireless module, for example, the WiFi module 32. If the mobile terminal 30 is connected for the first time, . In this embodiment, it is assumed that the mobile terminal 30 generates an IP add request message (IP add request) without a network change notification.

the eNB 41 may transmit an IP address request message (IP add request) to the switch 20 (S415). The switch 20 determines whether a network change notification is included in the IP address request message of the LTE module 31. The switch 20 transmits an IP address request message to the controller 10 if the IP address request message includes a network change notification. If the network address change request message does not include a network change notification, the switch 20 transmits an IP address And transmits a request message. The IP address issuing server (not shown) may be operated as a separate server or a P-GW of a Dynamic Host Configuration Protocol (DHCP) server or an LTE core network. The P-GW can assign an IP address in conjunction with a DHCP server.

Since this is the first connection in this process, the IP address request message does not include the network change notification. Accordingly, the switch 20 may transmit an IP address request message to the IP address issuing server to receive the IP address (IP add) assigned by the IP address issuing server (S420). The switch 20 may transmit the received IP address to the LTE module 31 through the eNB 41 (S430 and S435). This IP address setting is a type of wireless network setting of the LTE module 31. When the wireless network setting is completed by the LTE module 31, the mobile terminal 30 uses the LTE module 31 as an interface, The traffic can be exchanged with the switch 20 at step S440.

When the switch 20 receives the IP address request message (S415) or transmits / receives the traffic (S440), the switch 20 can inquire the controller 10 about the flow not in the flow table and update the flow entry. This process can be applied throughout this specification.

When the path setting between the LTE module 31 and the switch 20 is completed (S440), the controller 10 determines whether the mobile terminal network information including the IP address of the LTE module 31 of the mobile terminal 30 exists It can be judged. If there is no network information of the corresponding terminal, the controller 10 may generate a mobile network information request message (NW info req.) Requesting network information of the mobile terminal 30 and transmit it to the switch 20 (S445 ). The switch 20 may transmit the received mobile network information request message NW info req. To the eNB 41 (S450). The eNB 41 may transmit the received mobile network information request message NW info req. to the mobile terminal 30 through the LTE module 31 (S455).

Upon receiving the mobile terminal network information request message (NW info req.), The mobile terminal 30 can generate the mobile terminal network information NW info including the identification information of the WiFi module 32. The identification information of the WiFi module 32 is preferably a MAC address. The mobile terminal network information (NW info) may further include an IP address of the LTE module (31). The IP address of the LTE module 31 may be acquired in advance by the controller 10 through the switch 20 and the IP address of the LTE module 31 may be transmitted to the controller 10 by the mobile terminal 30 itself. . The mobile terminal network information NW info may further include default gateway information, a subnet mask, DNS (Domain Name Server) information, and the like.

The mobile terminal 30 can respond to the mobile terminal network information request message in response to the mobile terminal network information request message. The mobile terminal network information NW info may be transmitted to the controller 10 via the LTE module 31, the eNB 41 and the switch 20 (S460, S465, and S470). The controller 10 may store the received mobile terminal network information in a database. The above-mentioned request message or information message is contents included in the packet, and it is possible to modify the packet in the network element as needed. This can be applied throughout the specification.

the eNB 41 may transmit the network status such as a bearer status with the mobile terminal 30 to the controller 10 through the switch 20 at steps S475 and S480.

Based on various factors such as the network status of the bearer and the like, the QoS policy, the request of the user of the mobile terminal 30, and / or the instruction to change the network of the manager of the controller 10, It is possible to determine the traffic route change between the switches 20 (S510). Such network change or traffic path change is a kind of handover, and the mobile communication network and the WiFi network can be interlocked with each other.

When the handover of the mobile terminal 30 is determined (S510), the controller 10 generates an interface change message (I / F mod msg) including a command for the mobile terminal 30 to change the wireless interface To the mobile terminal 30. The controller 10 can designate a specific radio access device to which the mobile terminal 30 will connect among a plurality of identical radio access devices. That is, the controller 10 can designate a specific AP to which the mobile terminal 30 will connect among a plurality of APs. The specific AP designation of the controller 10 may take into consideration the LTE and WiFi signal strengths, the positional relationship between the mobile terminal 30 and a plurality of APs, and the like. The interface change message (I / F mod msg) may include an instruction to cause the mobile terminal to perform a handover operation to the designated AP. The interface change message (I / F mod msg.) May further include SSID information required for connection of the designated AP (42). The interface change message (I / F mod msg.) May further include a wireless encryption key required for encryption communication with the AP 42.

The interface change message (I / F mod msg) may be transmitted to the LTE module 31 via the switch 20 and the eNB 41 (S515, S520, S525).

When the mobile terminal 30 receives the interface change message (I / F mod msg) through the LTE module 31, the mobile terminal 30 can activate the WiFi module 32 (S530). The mobile terminal 30 may deactivate the LTE module 31 at the same time as activating the WiFi module 32 (S535). However, it is more preferable that the LTE module 31 is deactivated after the handover is completed. The mobile terminal 30 can maintain the activation of the LTE module 31 as needed. In this case, the mobile terminal 30 can distribute the traffic to the LTE module 31 and the WiFi module 32 or to distribute the traffic to the multi-path by the switch 20. [ This traffic distribution can reduce load burden on the network.

When the WiFi module 32 is activated, the WiFi module 32 can request the IP address to the AP 42 (S540). The IP address request can be a DHCP message (DHCP req.). The DHCP message may include identification information of the WiFi module 32, that is, a MAC address. The DHCP message may include a network change notification.

The AP 42 may transmit the received DHCP message to the switch 20 (S545). The switch 20 may determine whether the network change notification is included in the address request message and transmit the MAC address of the WiFi module 32 included in the DHCP message with the network change notification to the controller 10 in operation S550.

Upon receiving the MAC address from the switch 20, the controller 10 can retrieve the mobile station network information including the corresponding MAC address in the mobile terminal network information list. And the network setting information can be generated based on the retrieved mobile terminal network information. In this embodiment, the controller 10 generates network setting information for the WiFi module 32 including the same IP address as the IP address of the LTE module 31. So that a handover can be performed so as to maintain continuous traffic transmission / reception. The network setting information may include default gateway information, subnet mask, DNS information, and the like. The controller 10 can transmit the generated network configuration information config info to the WiFi module 32. [ The network configuration information config info may be transmitted from the controller 10 to the WiFi module 32 via the switch 20 and the AP 42 (S560, S565, S570).

The mobile terminal 30 can complete the network setting for the WiFi module 32 based on the network setting information received through the WiFi module 32. [ When the network setting for the WiFi module 32 is completed, the mobile terminal 30 can generate an interface change complete message (I / F change complete Msg.). The interface change complete message (I / F change complete Msg.) May be transmitted from the WiFi module 32 to the controller 10 via the AP 42 and the switch 20 (S580). The mobile terminal 30 can transmit and receive traffic to / from the switch 20 through the WiFi network (S600).

The switch 20 can close the path to the eNB 41 when it recognizes that the interface change of the mobile terminal 30 is completed by the interface change complete message (I / F change complete Msg.) (S590). The mobile terminal 30 may deactivate the LTE module 31 at the same time as or after generating the interface change complete message (I / F change complete Msg.). Whether or not the network path closure and the LTE module 31 are inactivated and the timing thereof may be optional. As described above, when the data path between the LTE module 31 and the switch 20 is maintained, the mobile terminal 30 or the switch 20 distributes the traffic to the multi-path according to the network status and the predetermined policy It is possible.

The present invention can be implemented in hardware or software. The present invention can also be embodied as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission via the Internet) . The computer readable recording medium may also be distributed over a networked computer system so that computer readable code can be stored and executed in a distributed manner. And functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers skilled in the art to which the present invention pertains.

Embodiments of the present invention may include a carrier wave having electronically readable control signals, which may be operated with a programmable computer system in which one of the methods described herein is implemented. Embodiments of the present invention may be implemented as a computer program product having program code, wherein the program code is operated to execute one of the methods when the computer program is run on a computer. The program code may be stored on, for example, a machine readable carrier. One embodiment of the invention may be a computer program having program code for executing one of the methods described herein when the computer program is run on a computer. The present invention may include a computer, or programmable logic device, for performing one of the methods described above. A programmable logic device (e.g., a field programmable gate array, a complementary metal oxide semiconductor based logic circuit) may be used to perform some or all of the functions described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

10: controller 20: SDN switch
30: mobile terminal 40: wireless access network

Claims (7)

Based on a SDN-based mobile terminal having first and second communication modules of different types of network interfaces and a first and a second wireless access device based on SDN (Software Defined Network) A method of changing a data path of an SDN-based controller,
Determining a network change that causes a data path between the mobile terminal and the SDN switch via the first wireless access device to pass through the second wireless access device; And
Generating a network change message corresponding to the network change,
If there is no identification information of the second communication module, acquires the mobile terminal network information including the IP address of the first communication module and the identification information of the second communication module through the SDN switch before the network change determination Further comprising the steps of: The method according to claim 1,
Wherein the network change determination is determined by at least one of a network status, a QoS policy, a configuration request by the user of the mobile terminal, and a configuration instruction by the SDN controller administrator. The method according to claim 1,
Wherein the network change message includes a command to cause the mobile terminal to access the second radio access device specified by the controller among a plurality of radio access devices of the same type as the second radio access device . The method according to claim 1,
Transmitting the generated network change message to the SDN switch and receiving an IP address request message for the second communication module of the mobile terminal; And
And generating second communication module network configuration information including the same IP address as the IP address of the first communication module from the mobile terminal network information. 5. The method of claim 4,
Wherein the mobile terminal network information and the second communication module network configuration information each include at least one of the same default gateway information, a subnet mask, and DNS (Domain Name Server) information. 5. The method of claim 4,
And the second communication module network configuration information is transmitted to the second communication module of the mobile terminal through the second wireless access device. delete

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