KR20030052774A - Method for protecting cutting off data stream transmission at situation registry and authentication in WLAN - Google Patents

Abstract

PURPOSE: A method for preventing data receiving from being interrupted during authentication and position registration in a wireless LAN is provided to simultaneously perform terminal cell access authentication and position registration of a terminal roaming to other cell from the wireless LAN, thereby preventing data receiving from being interrupted. CONSTITUTION: An AP(Access Point) informs a terminal of roaming confirmation(S310). The AP sets a connection with the terminal(S320). The AP sets a packet or a signal-capable state between a wired LAN and a cell(S330), and simultaneously performs an authentication procedure(S350) and a position registration procedure(S340). If cell access is authenticated in the authentication procedure(S350)(S351), the terminal is in a communication state of receiving a service through the AP of the cell(S360). If a mobile IP registration procedure is performed, the terminal is in a communication state of receiving the service through the AP(S360). If the cell access is not authenticated(S352), the terminal is not supplied with the service.

Description

How to prevent interruption of data reception during authentication and location registration in WLAN {Method for protecting cutting off data stream transmission at situation registry and authentication in WLAN}

The present invention relates to a wireless local area network (W-LAN). In particular, the present invention relates to terminal cell access authentication and location registration roaming to another cell in a wireless LAN in a mobile IP environment. The present invention relates to a method of preventing a disconnection of a service, i.e., interruption of data reception by performing the same.

In general, a wireless LAN of a mobile IP environment includes a plurality of cells formed by a plurality of access points (APs) and foreign agents (FAs) that perform wireless communication with mobile nodes and connect a wired network to a wireless network. ), And a mobile IP is given for one cell or a plurality of cells to ensure mobility of the terminal. Here, the FA may be configured as a device independent of the AP, but may be integrated with the AP.

Terminals in a wireless LAN are laptops, PCs, PDAs, PCSs, etc. that comply with the "802.11 x standard" capable of transmitting and receiving wireless signals while moving, and these terminals are roaming (roaming in the present invention means inter-cell movement). If the roaming fact is notified, the AP of the roaming cell is notified and the cell access authentication is performed through the authentication server.

The process in which the terminal roams and receives a service from the WLAN is illustrated in FIG. 1. 1 is a diagram illustrating an authentication process of a terminal roaming in a conventional WLAN. As shown in FIG. 1, in a wireless LAN of a conventional mobile IP environment, the terminal 10 notifies the AP 20 of roaming when roaming and requests a new connection between the terminal 10 and the AP 20 to be established. do. Then, the AP 20 establishes a new link with the terminal 10 (S10), and a setup response message including Service Set IDentification (SSID) information assigned to itself 20 (re-association response). After transmitting the massage to the terminal 10, by disabling a port connected to the wired LAN to set the packet forwarding inhibited state, signal transmission between the corresponding cell and the wired LAN is not performed ( S11).

As described above, when signal transmission between the wired LAN and the corresponding cell is prohibited, uploading, which is packet transmission from the WLAN to the wired LAN, is possible, but downloading, which is packet transmission from the wired LAN, to the WLAN is prohibited.

In this state, the terminal 10 transmits an authentication start message indicating the authentication start to the AP 20 (S12), and the AP 20 requests the terminal 10 to transmit the ID of the terminal 10 (S13). ). Accordingly, the terminal 10 transmits the terminal ID assigned to itself 10 to the authentication server 50 through the AP 20 (S14, S15), the authentication server 50 receives the terminal ID and the terminal ( A signal for requesting a password of 10 is transmitted to the terminal 10 through the AP 20 (S16 and S17), and a password of the terminal 10 is received (S18 and S19).

Then, the authentication server 50 performs authentication by comparing the received terminal ID and the password of the terminal with the stored information (S20), and the authentication completion message (approval message) to the terminal 10 through the AP 20. Transmit (S21.S22).

If the access authentication of the terminal 10 is approved through the above process, the AP 20 enables a signal transmission with the wired LAN by enabling a port connected to the wired backbone (S23).

In this packet forwarding state, the terminal 10 waits according to a timer or a predetermined criterion not defined to receive an Agent Advertisement Message (AAM) periodically transmitted from the FA 30 (S24). .

Here, the AAM includes a care of address (COA) indicating the current location of the terminal, where the COA is represented as a mobile IP in a wireless LAN of a mobile IP environment.

The terminal 10 receives the AAM from the FA 30 during the waiting period (S25), checks the COA (mobile IP assigned to each cell in the mobile IP environment) included in the AAM, and checks the FA 30. The mobile IP is transmitted to the HA 40 to request location registration (S26 and S27).

Then, the HA 40 receives the mobile IP of the terminal 10 received through the FA 30 and registers the current position for updating the current position of the terminal 10 (S28), and registers the registration response message with the FA ( Transfer to the terminal 10 through 30 (S29, S30). When the terminal 10 receives the registration response message from the HA 40, the terminal 10 knows that its location registration is successful, and then accesses the network through the AP 10 and transmits the packet to the AP 20. It can be received through (S31).

However, in the related art, while the authentication procedure is performed as shown in FIG. 1, the packet received from the wired LAN cannot be transmitted to the terminal 10 while the AP 20 is transmitted to the terminal 10 generated during the authentication procedure. The delay of transmission of packets, ie, user traffic, occurs, and furthermore, the delay of transmission of long user traffic is generated by performing the current location registration procedure of the terminal after the authentication procedure is prevented. do. Due to the propagation delay of the user traffic, the user traffic is discarded or buffered, and thus the service provided to the terminal is interrupted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to enable packet transmission to a terminal even during a cell access authentication procedure.

In addition, an object of the present invention is to prevent the service is disconnected due to packet delivery delay by performing the authentication of the terminal and the current location registration at the same time.

1 is a diagram illustrating an authentication and location registration process of a roaming terminal in a conventional WLAN.

2 is a diagram illustrating a configuration of a wireless LAN of a mobile IP environment to which the present invention is applied.

Figure 3 is a schematic diagram of a method for preventing the interruption of data reception during authentication and location registration in a wireless LAN according to an embodiment of the present invention.

4 is a diagram illustrating an authentication process of a terminal in a wireless LAN according to an embodiment of the present invention.

5 is a view showing a process in the case where the authentication server according to an embodiment of the present invention rejects the approval.

6 is a diagram illustrating an operation of an AP for processing an authentication procedure in response to a set time according to an embodiment of the present invention.

7 is a diagram illustrating a current location registration process of a terminal in a wireless LAN according to an embodiment of the present invention.

The present invention for achieving the above technical problem is a method for preventing the disconnection of data reception when performing location registration in a wireless LAN of a mobile IP environment including an AP, authentication server, FA and HA, the terminal cell in the authentication server Even during connection authentication, a packet received from a wired LAN is set to be delivered to a wireless LAN, thereby eliminating a packet delay.

To this end, when the connection between the terminal and the AP of the roaming cell is established, the present invention sets the state of the AP to a state capable of transmitting a signal between the wired LAN and the wireless LAN, thereby simultaneously performing an authentication procedure and a registration procedure.

Hereinafter, with reference to the accompanying drawings will be described a method for preventing the interruption of data reception during authentication and location registration in a wireless LAN according to an embodiment of the present invention.

First, an exemplary configuration of a wireless LAN of a mobile IP environment to which the present invention can be applied will be described with reference to FIG. 2. 2 is a diagram illustrating a configuration of a wireless LAN of a mobile IP environment to which the present invention is applied. As shown in FIG. 2, the wireless LAN of the mobile IP environment to which the present invention is applied is connected to a wired backbone network by wire, and a plurality of APs 210, 220,. ..) together with FAs 31, 320, ... form one cell c1, c2, ..., respectively.

In addition, the wired LAN network is connected to the HA 400 involved in the location registration and packet transmission of the terminal, and the authentication server 500 for the cell connection authentication of the terminal, the other network (NET) is connected. Therefore, the HA 400 and the authentication server 500 communicate with the AP or FA of the corresponding cell through the wired LAN network, and the packet transmitted from the network (NET) to the terminal 100 is delivered to the HA 400. The HA 400 is delivered to the terminal through the FA and the AP of the cell.

Accordingly, the APs 210, 220,... May serve as bridges connecting the base station or the existing wired backbone network to the wireless network. On the other hand, the AP (210, 220, ...) is built in the FA in some cases, in this case the AP includes the function of the FA. And, each AP (210, 220, ...) is assigned an SSID to distinguish each cell, FA (310, 320, ...) one cell to provide mobility of the terminal 100 Or it stores the mobile IP assigned to a plurality of aggregated cells.

Hereinafter, a method of preventing the interruption of data reception when performing location registration in a WLAN according to an embodiment of the present invention will be described with reference to FIGS. 2 to 5.

Figure 3 is a schematic diagram of a method for preventing the interruption of data reception during authentication and location registration in a wireless LAN according to an embodiment of the present invention.

As shown in FIG. 3, when the terminal 100 roams from the cell c1 to the cell c2, the terminal 100 notifies that the roaming is performed to the AP 220 of the cell c2. In this case, the terminal 100 receives a beacon frame from the AP 220 of the cell c2 to inform the roaming facts to the AP 220, transmits a response message for the beacon frame, or receives the beacon frame for a predetermined time. If not, the probe frame is transmitted to the AP 220 to inform that it has roamed to the cell c2. Here, the beacon frame is a frame transmitted from the AP 220 to all terminals visiting its cell, and the probe frame is a frame for perceiving the possibility of delivering a message. Then, the AP 220 notifies the roaming fact check by transmitting a response message to the terminal 100 according to the roaming fact notification signal received from the terminal 100 (S310).

Then, the AP 220 allows a connection between the terminal 100 and the AP 220 to be established at the request of the terminal 100 (S320).

When the connection between the terminal 100 and the AP 220 is established as described above, the AP 220 is configured to enable a packet or a signal between the wired LAN and the cell c2 (S330) and perform an authentication procedure (S350). And location registration (mobile IP registration) procedure (S340) to be performed at the same time.

Herein, the present invention sets a state capable of signal transmission between the wired LAN and the wireless LAN as described above, that is, between the AP 200, the FA 320, the HA 400, and the authentication server 500. Signal transmission is made possible, thereby enabling the authentication procedure and the location registration procedure to be performed simultaneously.

When the cell access authentication of the terminal is approved by the authentication procedure 350 (S351), the terminal 100 is in a communication state capable of receiving a service through the AP 220 of the cell c2 (S360). When the mobile IP registration procedure is performed, the terminal 100 is in a communication state capable of receiving a service through the AP 220 (S360).

In the above, if the cell connection authentication of the terminal 100 is denied in performing the authentication procedure (S352), after setting the signal transmission between the wired LAN and the wireless LAN is prohibited, the terminal 100 services through the AP 220. Do not be provided.

Hereinafter, the authentication procedure shown in FIG. 3 will be described in detail with reference to FIGS. 4, 5, and 6.

4 is a diagram illustrating an authentication process of a terminal in a wireless LAN according to an embodiment of the present invention.

As shown in FIG. 4, the AP 220 transmits a response message corresponding to a signal received from the terminal 100 to the terminal 10 to notify the roaming fact check, and thus, the terminal 100 receives the AP 220. A connection request signal for requesting establishment of a link for connection with the AP is transmitted to the AP 220, so that the AP 220 establishes a new connection with the terminal 100 (S410; FIG. 3). Same as step 320 shown in FIG.

In the above, when the AP 220 establishes a new connection with the terminal 100, the AP 220 notifies the terminal 100 of the fact as a connection response signal. In this case, the connection response signal includes information on a transmission interval, a transmission speed, an SSID, the performance of the terminal, and a supportable speed.

When the connection with the terminal 100 is established as described above, the AP 200 enables a signal connection between the wired LAN and the wireless LAN by enabling a port connected to the wired backbone, and at the same time, a timer. Then, it checks whether the authentication procedure execution time is within the set T1 time (S411; same as step 330 shown in FIG. 3).

(Certification process)

As soon as the terminal 100 receives the connection response signal from the AP 220, the terminal 100 transmits an authentication start message notifying the start of authentication to be approved for access to the AP 220 (S412). Then, the AP 220 requests the terminal 100 to transmit the ID of the terminal 100 (S413), and receives the terminal ID assigned to the terminal 10 from the terminal 100 (S414). It passes to 500 (S415).

When the authentication server 500 receives the terminal ID through the AP 200, the authentication server 500 transmits a signal requesting a password of the terminal 100 to the terminal 100 through the AP 200 (S416 and S417). As a result, the terminal 10 transmits its password to the authentication server 500 through the AP 200 (S418 and S419).

Here, the password transmission process (S412 to S416) between the terminal 100 and the authentication server 500 is a challenge response, which is a known method of authenticating identity by whether the terminal selects something to increase security. It is through the method. In more detail, the authentication server 500 transmits a randomly selected string sequence to the terminal 100, and the terminal 100 transmits the received string string and its password to a known algorithm. After encrypting using MD5 (message digest algorithm 5), the encrypted password is transmitted to the authentication server 500 again. Then, the authentication server 500 stores the randomly selected string string, and then extracts the password of the terminal 100 by removing the randomly selected string string from the encrypted password of the terminal 100.

Meanwhile, when the authentication server 300 receives the ID and password of the terminal 100, the authentication server 300 processes the authentication of the terminal 100 by comparing with the stored information (S420). The terminal 100 can use the service. If the authentication is approved, otherwise the authentication is rejected (S421). If the authentication of the terminal 100 is approved, the authentication server 500 transmits an authentication completion message (approval message) to the terminal 10 through the AP 20 (S422, S423).

As such, when the terminal 100 receives the authentication approval from the authentication server 500, the terminal 100 accesses the network NET through the AP 220 of the cell c2 and receives the desired service (S424).

Here, with reference to Figure 5 will be described the subsequent process of the case (A) when the authentication server 500 shown in Figure 4 rejects the approval. 5 is a view showing a process in the case where the authentication server according to an embodiment of the present invention rejects the approval.

As shown in FIG. 5, when the authentication server 500 rejects authentication of the terminal 100 (S450), the authentication server 500 transmits a message informing of the authentication rejection to the terminal 100 through the AP 220 (S451). Then, the AP 220 confirms the authentication rejection of the authentication server 500 to terminate the timer driving, that is, terminates the T1, and disables the enabled port to deliver the packet between the wired LAN and the cell c2. This is not done (S452). Meanwhile, as the authentication is denied, the terminal 100 requests reauthentication or stops cell access (S453).

Hereinafter, an authentication procedure processing procedure according to driving of the timer driven in step S411 of FIG. 4 will be described with reference to FIG. 6. 6 is a diagram illustrating an operation of an AP for processing an authentication procedure in response to a set time according to an embodiment of the present invention.

As shown in FIG. 6, the AP 220 establishes a connection with the terminal 100 (S410), and after enabling the port to enable packet forwarding at the same time and confirming the set time T1 (S411). In operation S460, a built-in timer is driven to check the time.

In this way, when the authentication approval is completed while the timer is running and counting the time (S461), the AP 220 maintains a packet forwarding state (S462), and the operation of the present invention from the process S422 shown in FIG. Let this proceed. However, if the authentication is not made until the timer is driven to exceed the set T1 time (S461 and S463), the AP 220 disables the port so that packets received from the wired LAN cannot be delivered to the WLAN. (S464). Then, the terminal 100 receives the authentication rejection message from the authentication server 500, and accordingly requests re-authentication or stops cell access (S452).

Hereinafter, the location registration procedure S340 performed simultaneously with the authentication procedure shown in FIG. 3 will be described in more detail with reference to FIG. 7. 7 is a diagram illustrating a current location registration process of a terminal in a wireless LAN according to an embodiment of the present invention.

As shown in FIG. 7, when a connection between the terminal 100 and the AP 220 is established (S710; same as step 320 shown in FIG. 3), the AP 220 may transmit a signal between the wired LAN and the wireless LAN. (S711; same as step S330 shown in FIG. 3), and transmits a connection setup response message to the terminal 100.

(Location registration procedure)

As described above, since the response message includes the SSID information assigned to the AP 220 of the cell c2, the terminal 100 extracts the SSID information included in the connection response signal, and the SSID currently owned by the UE. It is determined whether they are equal to each other by comparing with (S712).

The determination (S712) process is to determine whether the terminal 100 has changed the position to a new cell, the terminal 100 determines that the position is not changed if the same as the current SSID that the receiving SSID in the determination (S31) The location registration is not performed in the HA 300, and if the received SSID is different from the current SSID, it is determined that the location has been changed and the current location registration is performed in the HA 400.

Here, since the present invention relates to a case where the terminal 10 registers a location, assuming that the reception SSID and the current SSID are different, the terminal 100 registers its current location with the HA 400 without time delay. In step S713, a current location request signal (agent solicitation message) requesting information on its current location (mobile IP information) is transmitted.

Then, the FA 320 transmits an agent advertisement message (AAM) signal including mobile IP information assigned to the cell according to the current location request signal transmitted from the terminal 100 to the terminal 100 (S714). .

Accordingly, the terminal 100 extracts the mobile IP (COA) of the cell c2 roamed from the AAM signal to determine the current position, and compares whether the received (extracted) mobile IP is the same as the mobile IP currently held (S715). ).

Comparing the mobile IP (S44) is for managing the movement of the terminal 100 in a mobile IP environment, there is a first case in which a different mobile IP is assigned to each cell in a wireless LAN of the mobile IP environment, Since there is a second case in which a plurality of cells are used as one unit, and a different mobile IP is assigned to each unit, the mobile IP of the cell before the move and the mobile IP of the cell after the move even in the second case, even if the cell moves. Because may be the same.

Accordingly, the terminal 100 does not need to perform the process (S44) when different mobile IPs are assigned to each cell, but when the mobile IPs are assigned as a unit of a plurality of cells. If the received mobile IP and the current mobile IP are the same through the process (S44), the service is directly provided by wireless communication with the AP 220 without performing the current location registration, and if the received mobile IP and the current mobile IP are different, the received mobile IP is different. Performs a registration procedure to register with the HA (400).

If the received mobile IP is different from the current mobile IP, the terminal 100 transmits a location registration request signal including the received mobile IP information to the FA 320 (S716), and the FA 320 transmits the location registration request signal. To be delivered to the HA (400) (S717). Then, the HA 400 receives the location registration request signal of the terminal 100 received through the FA 320 and changes the location information of the currently stored terminal 100 to the received mobile IP included in the location registration request signal. Location registration is performed (S718).

In addition, the HA 400 transmits a message indicating the completion of location registration to the terminal 100 through the FA 320 (S719 and S720), so that the terminal 100 knows the location registration success.

As described above, when the terminal 100 registers the location with the HA 400, the terminal 100 may receive the packet transmitted by the HA 400 through the FA 320 and the AP 220, and then provide the wireless LAN. The service can be used (S721).

Meanwhile, the present invention is not only applied to a wireless LAN configuration in which an AP is connected to a wired backbone to transmit a transport packet of a terminal to a destination as shown in FIG. 2, and the transport packet of the terminal is transmitted to a destination through wireless communication between the AP and another AP. It can be applied to the WLAN configuration to enable. Since the packet transmission configuration of the terminal according to the wireless communication between the AP is already known, those skilled in the art can be easily implemented.

In addition, the present invention can be implemented not only in the WLAN shown in FIG. 2 in which the AP and the FA are configured as independent devices, but also in the WLAN in which the FA and the AP are configured as a single device. Applicable to all configured wireless LANs.

The technical spirit of the present invention has been described above with reference to the accompanying drawings, but this is by way of example only and not intended to limit the present invention. In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

The present invention prevents a packet from being transmitted from a wired LAN to a wireless LAN before a terminal roaming to another cell and performing authentication and location registration in the process of changing from a wireless LAN environment to a wireless IP environment of a mobile IP environment. Even if roaming is broken, packet delivery is possible, and authentication and location registration are performed at the same time, thereby preventing service interruption due to packet delivery time delay.

Claims (8)

In the method for preventing the interruption of data reception when performing location registration in a wireless LAN of a mobile IP environment including a plurality of AP, authentication server, and HA, A first step of notifying a roaming fact to an AP of a cell roaming by a terminal; A second step of establishing a connection between the terminal and the AP according to a request of the terminal; Setting a state of the AP to a packet forwarding state such that a packet can be forwarded to the WLAN; And A fourth step of simultaneously performing a cell access authentication procedure and a location registration procedure of the terminal; Method for preventing the interruption of data reception during authentication and location registration in the containing WLAN. The method of claim 1, In the third step, the packet forwarding state is A method for preventing disconnection of data reception during authentication and location registration in a wireless LAN, characterized in that achieved by enabling a port of the AP connected to a wired LAN network. The method of claim 1, And setting a T1 time at the same time as performing the second step and starting a time measurement for checking the expiration of the set T1 time, thereby preventing disconnection of data reception during authentication and location registration in a WLAN. How to. The method of claim 3, The time measurement of the fifth step is performed by a timer embedded in the AP, and the operation is stopped when the set T1 time expires or the authentication procedure is completed. How to prevent. The method of claim 4, wherein The authentication process of the fourth step, If the cell access authentication is approved within the set T1 time, an acknowledgment is transmitted to the terminal, and if the cell access authentication procedure is not completed or the cell access authentication is rejected within the T1 time, the port of the AP is set to the packet access inhibited state. And stopping the data reception during authentication and location registration in the wireless LAN, characterized in that the authentication procedure is stopped. The method of claim 1, The location registration procedure of the fourth step, Comparing, by the terminal, a first SSID received from an AP of the roaming cell and a second stored SSID to determine whether the first and second SSIDs are different; The terminal requesting and receiving first mobile IP information provided to the roamed cell for location registration, and forwarding the first mobile IP transmitted from the terminal to the HA to perform location registration; Method of preventing the interruption of data reception during authentication and location registration in a wireless LAN comprising a. The method of claim 6, Registering the location by transferring the first mobile IP to the HA, And comparing, by the terminal, the first mobile IP with the stored second mobile IP, when the authentication and location registration are performed in the WLAN. The method of claim 7, wherein Registering the location by transferring the first mobile IP to the HA, And performing data only when the first mobile IP and the second mobile IP are different from each other.