KR20140091913A - Method for accessing interworking wireless local area network, device, and recording medium thereof - Google Patents

Abstract

The present invention discloses an interworking wireless local area network (I-WLAN) access method and a device and a recording medium therefor. Specifically, a method for enabling a terminal to connect to the I-WLAN by considering an internet quality condition comprises a step of enabling a terminal to receive a domain name server (DNS) internet protocol (IP) address and a basic gateway IP address from an I-WLAN access point (AP); a step of enabling the terminal to determine the internet quality condition using the internet connection condition of the I-WLAN; and a step of setting basic routing using the received basic gateway IP address and by setting the DNS IP address as the DNS address of the terminal when the internet quality condition is good.

Description

Field of the Invention [0001] The present invention relates to an interworking wireless LAN access method, a device and a recording medium therefor,

The present invention relates to a method of connecting to an interworking wireless local area network (I-WLAN), and more particularly, to a wireless communication system interworking with a heterogeneous network, A device for the same, and a recording medium.

Recently, with the emergence of smartphones, the use of wireless communication services has been gradually expanded to provide various multimedia services such as video calls and Internet access as well as voice. As a result, the demand for various applications as well as high-speed data transmission has greatly increased, and the number of users who use the Internet by accessing a wireless local area network (WLAN) which provides a cost-effective and economical and high- .

In this way, when the user terminal accesses the access point (AP) of the WLAN, the terminal receives an IP (Internet Protocol) address through DHCP from the connected WLAN AP and receives a DNS (Domain Name System / Server) and receives the IP address of the gateway. In other words, the existing terminal performs system DNS setting and basic routing setting only once immediately after connecting to the WLAN AP. However, if there is a problem in the WAN (Wide Area Network) section of the WLAN AP, the terminal can not use the Internet, which is a problem that persists until the user disconnects from the WLAN AP.

An object of the present invention is to provide a method for dynamically controlling connection of a user terminal to an I-WLAN according to a result of an Internet quality test using a connection state of an I-WLAN (Interworking WLAN) in a wireless communication system in which a heterogeneous network is interlocked And a recording medium.

It is another object of the present invention to provide a method for dynamically controlling system DNS and basic routing settings according to a result of an Internet quality test using a connection state of an I-WLAN in a wireless communication system interworking with a heterogeneous network, Media.

It is also an object of the present invention to provide a communication system in which when an I-WLAN is disconnected while being connected to an I-WLAN in a wireless communication system in which a heterogeneous network is interworked, ), An apparatus and a recording medium therefor.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to another aspect of the present invention, there is provided an I-WLAN access method for accessing a WLAN by a terminal in consideration of an Internet quality state, The method comprising: receiving an Internet Protocol (IP) address and a basic gateway IP address; determining whether the terminal is in an Internet quality state using the Internet connection state of the I-WLAN; Setting the DNS IP address to the DNS address of the terminal, and performing basic routing using the received default gateway IP address.

Preferably, the step of determining determines whether the DNS IP address received by the terminal is routed to the I-WLAN and determines whether or not the terminal can access the DNS having the received DNS IP address.

Preferably, the determining step determines whether or not the IP address of the advanced packet data gateway (ePDG) is searchable in the DNS having the DNS IP address received by the terminal.

Preferably, the determining step determines that the terminal sets the IP address of the ePDG to be routed to the I-WLAN, and determines the Internet quality state based on whether or not the ePDG is reachable.

Preferably, the determining step comprises setting a preset IP address to be routed to the I-WLAN, and determining whether the terminal is capable of accessing a preset IP address through HTTP (hyper text transfer protocol) .

Preferably, the method further comprises confirming whether the terminal is capable of simultaneously connecting to the wireless communication network other than the I-WLAN and I-WLAN, if the internet quality condition is not good.

Preferably, when the terminal is capable of simultaneously connecting to the I-WLAN and another wireless communication network other than the I-WLAN, the connection to the other wireless communication network while maintaining the connection with the I-WLAN is performed.

Preferably, the method further includes the step of terminating the connection with the I-WLAN and performing the connection to the other wireless communication network when the terminal can not simultaneously access the I-WLAN and another wireless communication network other than the I-WLAN.

According to an aspect of the present invention, there is provided a terminal for accessing an I-WLAN in consideration of an Internet quality state, the terminal comprising: a transmission / reception unit for transmitting and receiving information; Name Server Receives an IP (Internet Protocol) address and a gateway IP address and determines the Internet quality status using the Internet connection status of the I-WLAN. If the Internet quality status is good, the received DNS IP address To the DNS address of the terminal, and performs a basic routing setting using the received basic gateway IP address.

Preferably, the control unit sets the received DNS IP address to be routed to the I-WLAN, and determines the Internet quality state based on whether or not the received DNS IP address is connectable to the DNS having the received DNS IP address.

Preferably, the control unit determines whether the IP address of the enhanced Packet Data Gateway (ePDG) is searchable in the DNS having the received DNS IP address.

Preferably, the control unit sets the IP address of the ePDG to be routed to the I-WLAN, and judges the Internet quality state based on whether or not the e-PDG is reachable.

Preferably, the control unit sets the predetermined IP address to be routed to the I-WLAN, and determines the Internet quality state based on whether or not the IP address can be connected to a preset IP address through HTTP (hyper text transfer protocol).

Preferably, the control unit checks whether simultaneous connection is possible to the wireless communication network other than the I-WLAN and the I-WLAN when the internet quality status is not good.

Preferably, when the I-WLAN and another wireless communication network other than the I-WLAN can be simultaneously connected, the control unit maintains connection with the I-WLAN and performs connection to another wireless communication network.

Preferably, when the simultaneous connection to the I-WLAN and another wireless communication network other than the I-WLAN is impossible, the control unit terminates the connection with the I-WLAN and performs connection to the other wireless communication network.

A computer readable recording medium storing a program of the present invention for achieving the above object is a computer readable recording medium having recorded thereon a program for allowing a terminal to access an I-WLAN in consideration of an Internet quality state, A function of receiving an Internet Protocol (IP) address of a DNS (Domain Name Server) and an IP address of a default gateway from an access point, a function of determining the Internet quality state using the Internet connection state of the I- If the status is good, it includes setting the received DNS IP address to the DNS address of the terminal and performing basic routing setting using the received default gateway IP address.

According to the embodiment of the present invention, the connection of the user terminal to the I-WLAN is dynamically controlled according to the result of the Internet quality test utilizing the connection state of the I-WLAN in the wireless communication system in which the heterogeneous networks are interlocked, The convenience can be increased.

According to the embodiment of the present invention, the system DNS and basic routing settings are dynamically controlled according to the result of the Internet quality test using the connection state of the I-WLAN in the wireless communication system in which the heterogeneous networks are interlocked, The convenience can be increased.

In addition, according to the embodiment of the present invention, when the user terminal accesses the WLAN, the I-WLAN connection is automatically performed, and only when the Internet quality of the I-WLAN is determined to be good, The convenience of the user can be increased.

In addition, according to the embodiment of the present invention, it is not necessary to communicate with a separate server for the Internet quality check in the system in which the I-WLAN is already operating, thereby reducing the network load.

The effects obtained in the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description .

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the technical features of the invention.
1 is a diagram showing an example of the configuration of a WLAN system.
2 is a diagram illustrating a procedure for a terminal to access an AP in a WLAN system.
3 is a diagram illustrating a signal transmission / reception process for a terminal to receive an IP address from an AP in a WLAN system.
4 is a diagram illustrating a network structure diagram to which the present invention can be applied.
5 is a diagram illustrating an interworking process of a heterogeneous wireless access system due to mobility of a terminal according to an embodiment of the present invention.
6 is a diagram illustrating a WLAN access method according to an embodiment of the present invention.
7 illustrates a block diagram of a wireless communication apparatus according to an embodiment of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. In the description of the drawings, there is no description of procedures or steps that may obscure the technical gist of the present invention, nor is any description of steps or steps enough to be understood by those skilled in the art.

Throughout the specification, when an element is referred to as "comprising" or " including ", it is meant that the element does not exclude other elements, do. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have. Also, the terms " a or ", "one "," the ", and the like are synonyms in the context of describing the invention (particularly in the context of the following claims) May be used in a sense including both singular and plural, unless the context clearly dictates otherwise.

The specific terms used in the embodiments of the present invention are provided to facilitate understanding of the present invention, and the use of such specific terms may be changed into other forms without departing from the technical idea of the present invention.

Embodiments of the present invention may be supported by standard documents disclosed in at least one of the IEEE 802 systems, 3GPP systems, 3GPP LTE and LTE-Advanced (LTE-Advanced) systems, and 3GPP2 systems, which are wireless access systems. That is, the steps or portions of the embodiments of the present invention that are not described in order to clearly illustrate the technical idea of the present invention can be supported by the documents. In addition, all terms disclosed in this document may be described by the standard document.

1. A wireless LAN to which the present invention can be applied WLAN : Wireless Local Area Network ) System General

1 is a diagram showing an example of the configuration of a WLAN system.

Referring to FIG. 1, a WLAN system includes one or more Basic Service Sets (BSSs). A BSS is a set of stations (STAs) that can successfully communicate and communicate with each other. In FIG. 1, two BSSs (BSS 1, BSS 2) and two STAs (STA 1, 2 / STA 3, 4) connected to each BSS are illustrated. In Fig. 1, an elliptical mark denotes a coverage area of a BSS, which is called a basic service area (BSA). If the STA moves beyond the BSA, the STA can no longer communicate directly with other STAs present in the BSA.

BSS is divided into Independent BSS (IBSS) and Infrastructure BSS (Infrastructure BSS). IBBS allows direct communication between STAs, and the type of inter-STA operation is called an ad hoc network.

In order for the STA to access the BSS, it must perform synchronization procedures with the base station. Also, in order to access all the services of the infrastructure BSS, the STA must be associated with the base station. This association procedure is performed dynamically and involves the use of a Distribution System Service (DSS).

The direct distance that can be supported between the STA and the STA may be physically limited. Depending on the network, this distance may be sufficient, but not enough and expansion of coverage may be required. Thus, the BSS may be composed of one element in an expanded form of the network consisting of a plurality of BSSs. Thus, the architectural element used to interconnect the BSSs is referred to as a distribution system (DS).

The DS is a mechanism for connecting a plurality of access points (APs), and is not necessarily a network, and there is no limitation in the form of a DS if it can provide a predetermined distribution service. For example, the DS may be a wireless network such as a mesh network, or may be a physical structure that links APs together.

In a WLAN system, a distibution system medium (DSM) and a wireless medium (WM) can be logically divided. Each logical medium is used for different purposes by different elements of the architecture. Device mobility is supported by the DS providing logical services needed to manage the seamless integration of multiple BSSs and address mapping to destinations.

An AP is an entity that allows the associated STA to access the distribution system via WM. Through this AP, data is moved between the BSS and the DS. Here, since all APs can be STAs, an AP is also an entity having an address. However, the addresses used by APs for communication via WM and for communication via DSM do not have to be the same.

A wireless network having an arbitrary size and complexity can be formed using DS and BSS, and this type of network is called an extended service set (ESS) network. An ESS refers to a plurality of BSSs connected through a DS and does not include a DS. Since the ESS network has the same logical link control (LLC) layer as the IBSS network, the STAs belonging to the ESS can move transparently from one BSS to another within the same ESS in the LLC .

BSSs may overlap partially to form physically continuous coverage. And, since the logical distance between BSSs is not limited, BSSs may not be physically connected. Also, BSSs may not be physically coupled to avoid unnecessary duplication. In addition, when the ad-hoc network operates in a location having an ESS network, or when a physically overlapping WLAN system network is set up in a different structure, or when a plurality of different connections or security policies are required at the same location More) An IBBS or ESS network may be physically in the same space as one (or more) ESS networks.

The STA is a logical entity including a medium access control (MAC) and a physical layer interface for a wireless medium, and includes an AP STA (AP Station) and a non-AP STA (Non-AP Station) do. A portable terminal operated by a user in the STA is a non-AP STA, and sometimes referred to as a non-AP STA. The non-AP STA may be a terminal, a wireless transmit / receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile terminal, May also be referred to as another name such as a Mobile Subscriber Unit. An AP is an entity that provides a connection to a distribution system (DS) through a wireless medium to an associated station (STA). The AP may be referred to as a centralized controller, a base station (BS), a Node-B, a base transceiver system (BTS), a femto BS (femto BS)

2 is a diagram illustrating a procedure for a terminal to access an AP in a WLAN system.

Referring to FIG. 2, the AP periodically generates and transmits a beacon frame in a broadcast format. The terminal receiving the beacon frame detects the presence of the access point. The beacon frame may be configured to include a header, a frame body, a frame check sequence (FCS), and may include a timestamp, a beacon interval, a capability, , A service set identifier (SSID), and supported rates. The service set identifier is an identifier used for distinguishing a plurality of different basic service sets in the WLAN system, and may also be referred to as a basic service set identifier (BSSID).

The terminal receives the beacon frame and confirms the presence of a plurality of access points accessible through the received beacon frames. This is called passive scanning. The terminal selects a specific AP among a plurality of APs and transmits a probe request frame to the selected AP.

On the other hand, the terminal can store the information of APs that have been connected to the AP as a profile. The terminal may store the information of the APs that have been previously connected as a profile, select the AP in the profile to be transmitted later without receiving the beacon frame, and transmit the probe request frame to the selected access point. This is called active scanning.

The probe request frame may be configured to include a header, a frame body, a frame check sequence (FCS), and may include information such as a service set identifier (SSID) and supported rates have. As described above, the service set identifier is an identifier used for distinguishing the basic service set. Any terminal that does not know the unique service set identifier of the specific basic service set can not access the corresponding basic service set. That is, in order to access a specific basic service set, that is, the AP, the terminal sends a service set identifier to the probe request frame.

The AP receiving the probe request frame transmits a probe response frame to the terminal in response to the probe request frame. The probe response frame may be configured to include a header, a frame body, a frame check sequence (FCS), and may include a timestamp, a beacon interval, a capability, An identifier (SSID), supported rates, and the like. Such a series of processes is called a search process.

After the searching process, the terminal and the AP perform an authentication process. Specifically, after receiving the probe response frame from the AP, the terminal transmits an authentication request frame to the AP to request authentication. Then, the AP transmits an Authentication Response frame to the terminal, thereby establishing authentication between the AP and the terminal. The authentication request frame and / or the authentication response frame may be configured to include a header, a frame body, a frame check sequence (FCS), and may include an authentication algorithm number, an authentication processing sequence number An authentication transaction sequence number, and a status code.

After the authentication process, the terminal and the AP perform an association process. Specifically, after establishing authentication between the AP and the UE, the UE transmits an association request frame to the AP. The association request frame may be configured to include a header, a frame body, a frame check sequence (FCS), and may include Capability, Listen interval, Service Set Identifier (SSID) And may include information such as supported rates.

The AP transmits an association response frame to the terminal in response to the association request frame, thereby being connected to the terminal. The association response frame may be configured to include a header, a frame body, a frame check sequence (FCS), and may include Capability, Status Code, Association ID (AID) , Supported rates, and the like. Here, the association identifier (AID) is a specific identifier assigned to each terminal by the AP in order to distinguish a plurality of terminals after the terminal associates with the AP.

3 is a diagram illustrating a signal transmission / reception process for a terminal to receive an IP address from an AP in a WLAN system.

Referring to FIG. 3, the UE connected to the AP according to the embodiment shown in FIG. 2 transmits a Dynamic Host Configuration Protocol (DHCP) Discover message requesting an IP address to the AP. At this time, since the terminal does not know its own IP address and the IP address of the AP as a DHCP server, it can transmit a DHCP discovery message in a broadcast format.

Upon receiving the DHCP DISK message, the AP sends a DHCP Offer message to the terminal in response to the DHCP DISK message. The DHCP-provided message includes information such as an IP address, a subnet mask, a period, and a DHCP address that can be allocated by the AP. At this time, since the IP address has not yet been assigned to the terminal, the AP can also transmit a DHCP-provided message in a broadcast manner.

The terminal selects a specific IP address from among the IP addresses included in the DHCP providing message and transmits a DHCP Request message to request the selected IP address to the AP. Then, the AP sends a DHCP Acknowledge (Ack) message, whereby the allocation of the IP address to the terminal is completed.

Meanwhile, the DHCP DISK message is a message transmitted by the UE for the first time to receive an IP address. Accordingly, if the IP address has expired after the IP address is allocated to the terminal, the transmission of the DHCP discovery message may be omitted. That is, when the terminal requests the AP to re-request the IP address, the terminal can receive the DHCP request message by sending the DHCP request message to the AP.

2. I- WLAN  Connection method

The present invention proposes a method for dynamically controlling the system DNS (Domain Name System / Server) and basic routing according to the Internet quality test result utilizing the I-WLAN (Interworking WLAN) connection state of the terminal.

Hereinafter, it is assumed that a terminal is a terminal having both a RAT (Radio Access Technology) function capable of communicating with a cellular mobile communication method and a RAT function capable of communicating with a WLAN communication method. Further, the I-WLAN referred to herein means a WLAN that is interworked with a mobile communication system (e.g., a 3GPP system).

It is also assumed that the I-WLAN AP according to the present invention is an AP connected to the Internet or an ISP (Internet Service Provider) network. 6 illustrates the structure of a network to which the present invention can be applied. However, the present invention is not limited thereto and may be applied to a wireless communication system supporting heterogeneous (multiple) wireless access networks.

4 is a diagram illustrating a network structure diagram to which the present invention can be applied.

The network structure diagram of FIG. 4 shows a schematic structure of an evolved packet system (EPS) including an EPC (Evolved Packet Core).

EPC is a key element of System Architecture Evolution (SAE) to improve the performance of 3GPP technologies. SAE is a research project that determines the network structure that supports mobility between various types of networks. SAE aims to provide an optimized packet-based system such as, for example, supporting various wireless access technologies on an IP-based basis and providing improved data transmission capabilities.

Specifically, the EPC is a core network of an IP mobile communication system for a 3GPP LTE system, and can support packet-based real-time and non-real-time services. In a conventional mobile communication system (i.e., a second- or third-generation mobile communication system), there are two distinct sub-domains: Circuit-Switched (CS) for voice and Packet- Function has been implemented. However, in the 3GPP LTE system, which is the evolution of the 3G mobile communication system, the CS and PS sub-domains are unified into one IP domain. That is, in the 3GPP LTE system, the connection between the UE and the UE having the IP capability is performed by an IP-based base station (eNodeB (evolved Node B), an EPC, an application domain (for example, IMS Multimedia Subsystem). That is, the EPC is an essential structure for implementing an end-to-end IP service.

EPC may include various components. In FIG. 4, a Serving Gateway (SGW), a Packet Data Network Gateway (PDN GW), a Mobility Management Entity (MME), a Serving GPRS Radio Service) Supporting Node, and Enhanced Packet Data Gateway (ePDG).

The SGW is an element that functions as a boundary between a radio access network (RAN) and a core network, and maintains a data path between the eNodeB and the PDN GW. In addition, when a terminal moves across an area served by an eNodeB, the SGW acts as a local mobility anchor point. That is, packets can be routed through the SGW for mobility within the Evolved-Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) defined after 3GPP Release-8 (release-8). In addition, the SGW can also provide mobility to other 3GPP networks (RANs defined before 3GPP Release-8, for example, UTRAN or GERAN (Global System for Mobile Communication) / EDGE (Enhanced Data Rates for Global Evolution) As an anchor point.

The PDN GW (or P-GW) corresponds to the termination point of the data interface towards the packet data network. The PDN GW can support policy enforcement features, packet filtering, and charging support. In addition, mobility management with a 3GPP network and a non-3GPP network (e.g., a trusted network such as an untrusted network such as Interworking Wireless Local Area Network (I-WLAN), Code Division Multiple Access (CDMA) It can serve as an anchor point for.

In the example of the network structure of FIG. 4, although the SGW and the PDN GW are configured as separate gateways, two gateways may be implemented according to the Single Gateway Configuration Option.

The MME is an element that performs signaling and control functions to support access to a network connection of a terminal, allocation, tracking, paging, roaming, and handover of network resources. The MME controls the control plane functions related to subscriber and session management. The MME manages a large number of eNodeBs and performs signaling for selection of conventional gateways for handover to other 2G / 3G networks. The MME also performs functions such as security procedures, terminal-to-network session handling, and idle terminal location management.

The SGSN handles all packet data such as the user's mobility management and authentication to another 3GPP network (e.g., GPRS network).

The ePDG acts as a secure node for an untrusted non-3GPP network (e.g., I-WLAN, WiFi hotspot, etc.).

As described with reference to FIG. 4, a terminal having an IP capability can access an IP service network (not shown) provided by a provider (i.e., an operator) via various elements in the EPC even in 3GPP access and non- For example, IMS).

5 is a diagram illustrating an interworking process of a heterogeneous wireless access system due to mobility of a terminal according to an embodiment of the present invention.

FIG. 5A is a diagram illustrating mobility of a mobile station in a space where cellular network coverage and I-WLAN coverage coexist. FIG. 5B illustrates a handover between a cellular network and an I-WLAN FIG. 5C is a schematic diagram illustrating an operation of connecting / disconnecting to / from an I-WLAN, in addition to connection with a cellular network.

Referring to FIG. 5, if the terminal is located within the service coverage of the base station of the cellular network but not within the service coverage of the I-WLAN AP, the terminal performs communication via the cellular network without being connected to the I- . Here, when the I-WLAN interface mounted on the terminal is activated, the terminal scans the beacon signal periodically transmitted from the I-WLAN AP.

Thereafter, when the terminal moves to the service coverage of the I-WLAN AP as in (1), the I-WLAN communication module of the terminal searches for the nearby I-WLAN AP through the beacon signal transmitted from the I-WLAN AP .

The terminal searching for the I-WLAN AP can perform continuous communication by performing a handover to the I-WLAN AP retrieved from the cellular network as shown in FIG. 5 (b). That is, the link with the cellular network is switched to the link with the I-WLAN, and the data transmitted and received through the cellular network can be continuously transmitted and received through the I-WLAN.

In addition, the terminal searching for the I-WLAN AP may further establish a new link with the I-WLAN while maintaining the link with the existing cellular network as shown in FIG. 5 (c). That is, the data transmitted and received through the existing cellular network continues to be transmitted and received through the cellular network, and the terminal may transmit and receive new data through the I-WLAN.

If the UE moves beyond the service coverage of the I-WLAN AP, the UE is disconnected from the connected I-WLAN AP and performs communication only through the cellular network.

Here, as shown in (b) of FIG. 5, the terminal can perform continuous communication by performing handover from the I-WLAN to the cellular network again. That is, the link with the I-WLAN is switched to the link with the cellular network, and the data transmitted / received through the I-WLAN can be continuously transmitted / received through the cellular network.

In addition, when the link with the existing cellular network is maintained as shown in FIG. 5 (c), the link with the cellular network can be maintained even if the link with the I-WLAN is lost. That is, the transmission and reception of data through the I-WLAN is interrupted, and the data transmitted and received through the existing cellular network can be continuously transmitted and received through the cellular network.

In FIG. 5, for convenience of description, the terminal has assumed the mobility of the terminal in a space where the coverage of the cellular network and the coverage of the I-WLAN coexist. However, the present invention is not limited thereto. The operation of the terminal can be performed according to the quality of the terminal.

In the present invention, even if the terminal succeeds in accessing the searched I-WLAN AP, the terminal directly checks the service quality of the I-WLAN without performing communication via the I-WLAN, It is proposed to perform communication through the I-WLAN only when it is confirmed that it is normal. That is, the UE does not perform communication through the searched I-WLAN AP until it confirms that the service quality of the I-WLAN is normal, and can continuously perform communication through only the existing connected cellular network. When it is confirmed that the quality of service of the I-WLAN is normal, the UE performs handover from the cellular network to the I-WLAN so that the link with the existing cellular network is switched to the I-WLAN or the link with the existing cellular network And establish a new link with the I-WLAN.

6 is a diagram illustrating an I-WLAN access method according to an Internet quality according to an embodiment of the present invention.

Referring to FIG. 6, the terminal accesses the searched I-WLAN AP and receives a DHCP IP address from the connected I-WLAN AP (S601). Here, the I-WLAN AP allocates an IP address to the terminal, and transmits the DNS IP address and the basic gateway IP address to the terminal. As described above, the AP associated with the terminal functions as a DHCP server and transmits a DHCP Ack message to the terminal in response to a DHCP Request message received from the terminal Thereby assigning an IP address to the terminal.

The terminal receiving the DNS IP address and the default gateway IP address from the I-WLAN AP does not reflect the received DNS and the default gateway IP address in the system DNS and default gateway setting (S603). Here, DNS refers to a system (or a device) that converts the name of a domain or a host in a network to a numeric IP address or vice versa, and the basic gateway is a system Means a gateway used by default among one or more gateways.

Then, the terminal performs an Internet quality check using the I-WLAN connection status (S605), and determines whether the Internet quality status is good (S607). That is, the terminal can determine the Internet quality state using the Internet connection state of the I-WLAN. Here, the terminal may perform Internet communication through another communication interface while performing the Internet quality check. For example, the terminal may perform Internet quality checking through an I-WLAN connection state while performing Internet communication through a cellular network.

The Internet quality test method for the I-WLAN of the terminal is as follows. The Internet quality inspection schemes described below may be used independently of each other, or at least two schemes may be used in combination.

1) The UE sets the DNS IP address provided by the I-WLAN AP to be routed to the I-WLAN, and the UE attempts to access the DNS through the DNS IP address provided by the I-WLAN AP (S605). If the connection to the DNS is successful, the terminal determines that the internet quality is good. If the connection to the DNS is unsuccessful, the terminal determines that the internet quality is bad (S607).

2) The terminal retrieves the IP address of the ePDG (or packet data interworking function (PDIF)) server of the I-WLAN from the DNS described above. That is, the terminal attempts to retrieve the IP address of the ePDG or the PDIF server from the DNS provided by the I-WLAN AP (S605). If the search of the IP address of the ePDG or the PDIF server is successful in DNS, If the search of the IP address of the ePDG or the PDIF server in the DNS fails, the terminal determines that the internet quality is poor (S607). Here, the terminal can check whether the DNS system provided by the I-WLAN AP or the internal DNS system operated by the Internet service provider (ISP) is normal through searching the IP address of the ePDG or the PDIF server in the DNS. That is, the UE can confirm whether the internal network of the ISP connected to the WLAN AP is operating normally.

3) The UE sets the IP address of the ePDG (or PDIF) server of the I-WLAN to be routed to the WLAN, and the UE attempts to connect to the ePDG (or PDIF) server (S605). If the connection to the ePDG (or PDIF) server is successful within a preset predetermined time, the terminal determines that the internet quality is good. If the connection with the ePDG (or PDIF) server fails within a preset predetermined time, (S607). Here, an attempt to connect to the ePDG (or PDIF) server means that the UE verifies that the connection to the internal network of the mobile communication company is possible.

In general, a mobile communication company provides its own dedicated mobile communication service, and as described above, the ePDG serves as a security node for an untrusted non-3GPP network (I-WLAN). Therefore, it is not possible to connect to the internal network of a mobile communication company with a general untrusted connection for the purpose of security of the mobile communication company. That is, attempting to connect to the ePDG (or PDIF) server at the terminal means that a VPN (Virtual Private Network) connection is attempted from the terminal to the ePDG of the mobile communication company. When the VPN is connected, And the like.

4) If the previous 3) is unsuccessful, the terminal searches for the IP address of a predetermined server in the DNS described above, and sets the IP address of a predetermined server to be routed to the I-WLAN. (or a device) such as a portal server (S605). If the connection with the predetermined server is successful, the terminal determines that the internet quality is good. If the connection with the predetermined server fails, the terminal determines that the internet quality is bad (S607). Here, the I-WLAN AP may be a paid Wi-Fi hotspot using a redirect.

After confirming that the exclusive service of the mobile communication company is unavailable by failing in the above 3), the terminal can confirm whether or not the general Internet can not be used. Dedicated services provided by mobile carriers are not available, but if the Internet portals are available, a simple Internet is available. However, if the HTTP connection fails, it indicates that only the internal network of the connected I-WLAN AP can be used, which means that it can not be connected to the Internet.

If it is determined in step S607 that the Internet quality for the I-WLAN is good, the terminal performs the system DNS and default routing settings that were reserved in step S603 (S609). That is, the DNS IP address received in step S603 is set as the DNS server address of the terminal to be referred to in the domain query, and basic routing is set using the basic gateway address. Then, the terminal performs Internet communication through the I-WLAN (S611). Thereafter, the terminal performing the Internet communication through the I-WLAN branches to step S605 and periodically or non-periodically performs the Internet quality test using the I-WLAN connection status.

On the other hand, if it is determined in step S607 that the Internet quality for the I-WLAN is poor, the terminal determines whether the I-WLAN and another communication interface can be activated simultaneously (S613). That is, the UE confirms whether or not the I-WLAN and another wireless communication network can be simultaneously connected. For example, the terminal can confirm whether the I-WLAN interface module and the cellular network interface module can be simultaneously activated and simultaneously access the I-WLAN and the cellular network.

Meanwhile, if the I-WLAN connection is terminated after the terminal determines that the Internet quality for the I-WLAN is good in step S607 and performs Internet communication through the I-WLAN, step S613 may be performed.

In step S613, if the simultaneous connection to the I-WLAN and the other wireless communication network is impossible, the terminal terminates the I-WLAN connection and connects to the other wireless communication network (e.g., cellular network) (S615). That is, the terminal deactivates the I-WLAN interface module, activates only the other wireless communication network interface module, and performs Internet communication through the other wireless communication network. In this case, the terminal can use the value set in the other wireless communication network for DNS and basic lighting.

On the other hand, if it is possible to simultaneously access the I-WLAN and another wireless communication network (for example, a cellular network) in step S613, Internet communication is performed through another communication interface (S617). That is, the terminal selectively activates or deactivates the I-WLAN interface module, and performs Internet communication through another wireless communication network using another wireless communication network interface module. In this case, the terminal can use the value set in the other wireless communication network for DNS and basic lighting. Thereafter, the terminal performing the Internet communication through the other wireless communication network branches to step S605 and periodically or non-periodically performs the Internet quality test using the I-WLAN connection state.

3. Devices in which the present invention may be implemented

7 illustrates a block diagram of a wireless communication apparatus according to an embodiment of the present invention.

The AP 70 includes a control unit 71, a storage unit 72, and a transmission / reception unit 73. The control unit 71 implements the proposed functions, procedures and / or methods. The layers of the wired / wireless interface protocol can be implemented by the control unit 71. The storage unit 72 is connected to the control unit 71 and stores various information for driving the control unit 71. [ The transceiver unit 73 is connected to the control unit 71 to transmit and / or receive a wired / wireless signal.

The terminal 80 includes a control unit 81, a storage unit 82, and a transmission / reception unit 83. The control unit 81 implements the proposed functions, procedures and / or methods. The layers of the wired / wireless interface protocol can be implemented by the control unit 81. The storage unit 82 is connected to the control unit 81 and stores various information for driving the control unit 81. The transmission / reception unit 83 is connected to the control unit 81 to transmit and / or receive a wired / wireless signal.

The storage units 72 and 82 may be located inside or outside the control units 71 and 81 and may be connected to the control units 71 and 81 by various well known means. In addition, the AP 70 and / or the terminal 80 may have a single antenna or multiple antennas. The storage units 72 and 82 may be implemented by various storage means. For example, the storage units 72 and 82 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, SD Or XD memory), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read- Memory, a magnetic memory, a magnetic disk, and an optical disk.

In this document, the embodiments of the present invention have been mainly described with reference to the data transmission / reception relationship between the terminal and the AP. The specific operation described herein as being performed by an AP may be performed by its upper node, as the case may be. That is, it is apparent that various operations performed for communication with a terminal in a network including a plurality of network nodes including an AP can be performed by other network nodes other than the AP or the AP. The access point may be replaced by terms such as a base station, a fixed station, a Node B, an eNode B (eNB), an Internet router, an IP router, and the like. In addition, the terminal may be replaced by terms such as a UE (User Equipment), a Mobile Station (MS), and a Mobile Subscriber Station (MSS).

The embodiments described above are those in which the elements and features of the present invention are combined in a predetermined form. Each component or feature shall be considered optional unless otherwise expressly stated. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to construct embodiments of the present invention by combining some of the elements and / or features. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is clear that the claims that are not expressly cited in the claims may be combined to form an embodiment or be included in a new claim by an amendment after the application.

Embodiments in accordance with the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) field programmable gate arrays, processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, a procedure, a function, or the like which performs the functions or operations described above. The software code can be stored in memory and driven by the processor. The memory is located inside or outside the processor, and can exchange data with the processor by various means already known.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the foregoing detailed description is to be considered in all respects illustrative and not restrictive. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

The WLAN connection scheme according to the present invention can be applied to various wireless communication systems.

70: Access point 71:
72: storage unit 73: transmission /
80: terminal 81:
82: Storage unit 83: Transmitting /

Claims (17)

A method for a terminal to access an Interworking Wireless Local Area Network (I-WLAN) in consideration of an Internet quality state,
Receiving a Domain Name Server (DNS) IP address and a basic gateway IP address from an I-WLAN Access Point (AP);
Determining the Internet quality status using the Internet connection status of the I-WLAN; And
And setting the basic DNS to a DNS address of the terminal if the Internet quality state is good and performing a basic routing setting using the received basic IP address of the terminal, I-WLAN access method. 2. The method according to claim 1,
Wherein the terminal sets the received DNS IP address to be routed to the I-WLAN, and determines the Internet quality state based on whether or not the received DNS IP address is connectable to the DNS having the received DNS IP address. 3. The method according to claim 2,
Wherein the terminal determines the Internet quality state based on whether the IP address of an enhanced Packet Data Gateway (ePDG) is searchable in the DNS having the received DNS IP address. 4. The method of claim 3,
Wherein the terminal sets the IP address of the ePDG to be routed to the I-WLAN, and determines the Internet quality state based on whether or not the ePDG is reachable. 5. The method of claim 4,
Wherein the terminal is configured to route a pre-established IP address to the I-WLAN and to determine the Internet quality state through whether the terminal is able to access the preset IP address via hypertext transfer protocol (HTTP) Way. The method according to claim 1,
Further comprising the step of determining whether the terminal is capable of simultaneous connection to the I-WLAN and a wireless communication network other than the I-WLAN if the Internet quality status is not good. The method according to claim 6,
Further comprising performing connection to the other wireless communication network while maintaining connection with the I-WLAN when the terminal is capable of simultaneously connecting to the I-WLAN and another wireless communication network other than the I-WLAN , An I-WLAN access method. The method according to claim 6,
And terminating the connection with the I-WLAN and performing connection to the other wireless communication network when the terminal can not simultaneously access the I-WLAN and another wireless communication network other than the I-WLAN , An I-WLAN access method. A terminal for accessing an Interworking Wireless Local Area Network (I-WLAN) in consideration of an Internet quality state,
A transmitting and receiving unit for transmitting and receiving information; And
Receives an Internet Protocol (IP) address and a gateway IP address of a Domain Name Server (DNS) from an I-WLAN Access Point (AP) and determines the Internet quality state using the Internet connection state of the I-WLAN And a controller configured to set basic routing using the received basic IP address of the terminal and the DNS IP address of the terminal if the Internet quality state is good. 10. The apparatus according to claim 9,
Setting the received DNS IP address to be routed to the I-WLAN, and determining the Internet quality state based on whether the received DNS IP address is connectable to the DNS having the received DNS IP address. 11. The apparatus according to claim 10,
And determines whether the IP address of the enhanced Packet Data Gateway (ePDG) is retrievable from the DNS having the received DNS IP address. 12. The apparatus according to claim 11,
Establishing the IP address of the ePDG to be routed to the I-WLAN, and determining the Internet quality state based on whether or not the ePDG is reachable. 13. The apparatus according to claim 12,
Wherein the terminal is configured to set a predetermined IP address to be routed to the I-WLAN and to determine the Internet quality state based on whether the IP address is connectable to the preset IP address through hypertext transfer protocol (HTTP). 10. The apparatus according to claim 9,
And confirms whether simultaneous access to the I-WLAN and a wireless communication network other than the I-WLAN is possible if the Internet quality state is not good. 15. The apparatus of claim 14,
And performs connection to the other wireless communication network while maintaining connection with the I-WLAN when the I-WLAN and another wireless communication network other than the I-WLAN can be simultaneously connected. 15. The apparatus of claim 14,
And terminates the connection with the I-WLAN and performs connection to the other wireless communication network when the simultaneous connection to the I-WLAN and another wireless communication network other than the I-WLAN is impossible. A computer-readable recording medium storing a program for allowing a terminal to access an Interworking Wireless Local Area Network (I-WLAN) in consideration of an Internet quality state,
Receiving a DNS (Domain Name Server) IP (Internet Protocol) address and a basic gateway IP address from an I-WLAN access point (AP);
A function of determining an Internet quality status using the Internet connection status of the I-WLAN; And
Setting the received DNS IP address as a DNS address of the terminal and performing basic routing setting using the received IP address of the terminal when the Internet quality state is good, A computer readable recording medium.

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