KR101197281B1 - Integarated mobility management server and method for supporting mobility in the network management system based on wireless communication network - Google Patents

Abstract

A mobility management server supporting mobility of a mobile terminal, comprising: a physical address authenticator authenticating a physical address of a predetermined mobile terminal based on a physical address table, and a physical address of an authenticated mobile terminal as a physical address of the mobility management server A physical address conversion unit for converting, an IP address conversion unit for converting an IP address of the authenticated mobile terminal into a fixed IP address given by the physical address table, and the authenticated movement using the converted physical address and IP address And a communication relay unit for communicating with the terminal and the network management center.

Description

INTEGARATED MOBILITY MANAGEMENT SERVER AND METHOD FOR SUPPORTING MOBILITY IN THE NETWORK MANAGEMENT SYSTEM BASED ON WIRELESS COMMUNICATION NETWORK}

The present invention relates to a mobility management server and method for mobility support in a wireless network based network management system.

Today, many corporate personal computers are connected by a network (LAN), and each personal computer user can access the Internet through a local area network (LAN) as well as exchange data between computers. However, the existing wired LAN has a disadvantage in that it is possible to provide a service through a limited space and cabling requiring high installation cost. The wireless LAN, a technology developed to compensate for these drawbacks, can transmit and receive data over the air, rather than the conventional wire, to provide a service provided by the existing wired LAN.

In recent years, wireless LANs are being used to connect to the Internet or to work with computers while traveling. In addition, devices that can utilize the wireless LAN is increasingly diversified, such as a portable terminal, a smart phone, a tablet PC, as well as a computer, and accordingly, more and more users are using the service by accessing the wireless LAN.

Wireless LAN has the advantages of LAN that can share various information and resources and convenience of providing unlimited connectivity, and has the advantages of flexibility and ease of installation as well as reliable data transmission. Wireless LANs in particular are not restricted by geopolitical installation because they do not use cables. In addition, wireless LANs can significantly reduce human and economic costs compared to wired LANs because there is no need to expand or change a line even when the mobile terminal is changed or added or deleted.

However, since wireless LANs may cause interference between frequencies and a narrow range of wireless communication networks, frequent handovers may occur, and thus mobility support of mobile terminals may be difficult.

1 is an overall configuration diagram showing a network system of a general wireless LAN.

As shown in FIG. 1, a network system of a wireless LAN according to an embodiment of the prior art includes a print 100, a personal computer 110, a server 120, a broadband modem 130, an access router 140, and a bridge. Or a switch 150, an access point 160, a mobile terminal 170, and a notebook 180.

The basic structure of a standardized network in an IEEE 802.11 WLAN is one basic service set (BSS), which forms a single access point (AP), a plurality of mobile terminals connected thereto, and a DS to form an extended service set (ESS). It may be connected and configured through a backbone called a distribution system. The ESS provides a seamless wireless LAN service and is required when handing over from one AP to another. In an 802.11 WLAN structure, a plurality of APs may be connected via Ethernet, and in general, an AP may be configured as a second layer switch or a bridge device.

In FIG. 1, SS (Station Service) refers to a service provided between mobile terminals, and services such as authentication and quality of service (QoS) are possible, and DSS (Distribution System Service) is a service provided by DS as association, distribution, Services such as reassociation can be provided.

According to the prior art of the WLAN, MAC frame of 802.11 can be largely divided into MAC header, frame body, FCS. In this case, the MAC header includes information such as frame control, duration, address, sequence control information, QoS control information, and the like, and the frame body includes a frame type and a subtype. A total of four address fields in the MAC header may have information such as a basic service set ID (BSSID), a source address (SA), a destination address (DA), a transmitting STA address (TA), and a receiving STA address (RA). Here, the source MAC address is the MAC address of the mobile terminal, the destination MAC address means the MAC address of the target to which the mobile terminal wants to communicate. In addition, since the MAC header component is a component not related to the present invention, a separate description is not provided. In FIG. 1, when transmitted through a DS to a wired network, an 802.3 based Ethernet MAC header includes a destination MAC address and a source MAC address. The present invention can perform a process of creating a MAC table and converting a destination MAC address based on the source MAC address of the mobile terminal transmitted in this procedure.

On the other hand, in such a wireless LAN environment, since the user device managed by the network center is not fixed and moves, frequent log disconnections occur in the network center, which makes it difficult to efficiently manage the user device. In addition, packet loss, delay time, and the like may occur during handover, thereby preventing smooth mobility for the user device.

One embodiment of the present invention provides a mobility management server and method capable of performing a handover based on a triggering response message transmitted from a mobile terminal.

In addition, an embodiment of the present invention provides a mobility management server and method capable of continuously maintaining a connection log by converting a physical address and an IP address using a physical address table.

In addition, an embodiment of the present invention performs buffering for packets to be transmitted to the mobile terminal, thereby preventing excessive delay time caused by short communication radius of the network management system using the wireless communication network and packet loss caused by such delay time. Provides a mobility management server and method that can be.

As a technical means for achieving the above-described technical problem, an embodiment of the present invention, in a mobility management server supporting mobility of a mobile terminal, a physical address for authenticating a physical address of a predetermined mobile terminal based on a physical address table Authentication unit, a physical address conversion unit for converting the physical address of the authenticated mobile terminal to the physical address of the mobility management server, IP for converting the IP address of the authenticated mobile terminal to a fixed IP address given by the physical address table Including a address translator and a communication relay unit for communicating with the authenticated mobile terminal and the network management center using the converted physical address and IP address to support the mobility of the mobile terminal in a wireless network-based network management system Provide mobility management server Can.

Further, another embodiment of the present invention is to authenticate the physical address of the mobile terminal based on the physical address of the predetermined mobile terminal stored in the physical address table, the physical address of the authenticated mobile terminal to the physical address of the mobility management server Converting and communicating with the mobile terminal and a network management center using the translated physical address and a fixed IP address corresponding to the converted physical address. A mobility management method supporting mobility of a terminal can be provided.

According to the above-described problem solving means of the present invention, it is possible to continuously maintain the access log by converting the physical address and IP address using the physical address table.

In addition, according to the aforementioned problem solving means of the present invention, by performing buffering for the packet to be transmitted to the mobile terminal, due to the excessive delay time caused by the short communication radius of the network management system using the wireless communication network and the Packet loss can be prevented.

1 is an overall configuration diagram showing a network system of a general wireless LAN.
2 is an overall configuration diagram showing a network system of a wireless LAN according to an embodiment of the present invention.
3 is a detailed block diagram showing the configuration of a mobility management server according to an embodiment of the present invention.
4 is a flowchart illustrating a handover procedure of a mobile terminal according to an embodiment of the present invention.
5 is a flowchart illustrating a mobility management method according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is an overall configuration diagram showing a network system of a wireless LAN according to an embodiment of the present invention.

2, a wireless LAN network system includes a mobile terminal 200, a first access point 210, a second access point 220, a first access router 230, a second access router 240, The backbone router 250, the mobility management server 300, and the network management center 400 are included. Here, the mobility management server 300 may be located between the network management center 400 and the backbone router 250 to control all packets that attempt to access the network management center 400. In addition, the mobility management server 300 may prevent packet loss, delay time, and truncation of the access log due to handover occurring while the network user uses the wireless LAN. Therefore, the network user using the mobile terminal 200 communicates with the network management center 400 using the wireless LAN, and can be supported by the mobility management server 300 in the wireless communication network.

When the mobile terminal 200 moves toward the second access point 220 while initially maintaining a connection with the first access point 210, the mobile terminal 200 may execute handover. In this case, the mobility management server 300 may convert the source physical address and the source IP address of the mobile terminal 200 using the physical address table, thereby preventing the connection log with the network management center 400 from being disconnected. . In addition, the mobility management server 300 may prevent packet loss that may occur by performing buffering on a packet to be transmitted to the mobile terminal during handover.

The stated operation will be described in detail with reference to FIG. 3.

3 is a detailed block diagram showing the configuration of a mobility management server according to an embodiment of the present invention.

Referring to FIG. 3, the mobility management server 300 may include a physical address authenticator 310, a physical address translator 320, an IP address translator 330, a handover determiner 340, and a packet buffering performer ( 350, a communication relay unit 360.

The physical address authenticator 310 authenticates the physical address of the mobile terminal 200 based on the physical address table. Here, the mobility management server 300 may configure a physical address table in the initial installation process. Table 1 is an example of a physical address table (hereinafter referred to as MAC table) configured in the mobility management server 300.

The MAC table includes MAC addresses M1, M2, and M3 of a predetermined mobile terminal, a fixed IP address corresponding to a predetermined MAC address of a mobile terminal, whether a triggering ACK occurs, a destination port number, an address type, and the like. The user is registered in advance for the network user to include the information, and the registration procedure is not described because it is far from what is described in the present invention.

MAC address Address type Unique IP Triggering ACK Priority M1 Self 192.168.1.5 0 One M2 Dynamic 192.168.1.6 0 2 M3 Static 192.168.1.7 One 3

The physical address authentication unit 310 may determine whether to access the mobile terminal 200 based on the MAC table. The physical address authentication unit 310 passes only the MAC addresses (M1, M2, M3) of the mobile terminal registered in the MAC table in Table 1, and all other packets are denied access to the network management center 400. Can be. As the flexible IP in the wireless network is used, the mobility management server 300 cannot determine whether the mobile terminal 200 is used by the network user using only the third layer IP address. The MAC address of the mobile terminal 200 corresponding to the MAC table may be authenticated to determine whether the mobile terminal 200 is connected.

The physical address conversion unit 320 converts the physical address of the mobile terminal 200 to the physical address of the mobility management server 300. The physical address conversion unit 320 may convert the source MAC address, that is, the MAC address of the mobile terminal 200, into the MAC address of the mobility management server 300 in the second layer header of the transmitted packet. This procedure causes the network management center 400 to recognize the source MAC address as the mobility management server 300, so that when the mobile terminal 200 hands over, the network management center 400 knows the progress of the handover. The connection with the network management center 400 may be maintained continuously.

The IP address conversion unit 330 converts the IP address of the mobile terminal into a fixed IP address corresponding to the MAC address of the mobile terminal predetermined by the MAC table. The IP address conversion unit 330 may convert the floating IP address used in the wireless LAN into a fixed IP address, as specified in Table 1.

Here, the mobility management server 300 converts the source IP address from the third layer IP header of the transmitted packet into a fixed IP address corresponding to the MAC address of the mobile terminal predetermined by the MAC table, thereby providing a physical address conversion unit ( As in 320, the network management center 400 may recognize the source IP address as the mobility management server 300. Accordingly, the IP address conversion unit 330 may maintain the access log with the network management center 400 even after the mobile terminal 200 of the network user completes the handover.

The handover determination unit 340 determines whether the mobile terminal 200 is handed over. The handover determination unit 340 may perform a handover by transmitting a triggering response message (hereinafter triggering ACK) indicating a handover from the access point (AP) connected to the mobile terminal 200 to the mobility management server 300. have.

Referring to Table 1, the AP may indicate 0 or 1 in the MAC table according to whether the triggering ACK occurs. In this case, when the triggering ACK is 0 in the MAC table, the triggering ACK does not occur. When the triggering ACK is 1, it means that the triggering ACK is generated. Accordingly, if the handover determination unit 340 does not transmit the triggering ACK to the mobility management server 300, the handover may not be performed. If the handover determination unit 340 transmits the triggering ACK, the handover may be performed.

That is, the criteria for determining whether the mobility management server 300 handovers the mobile terminal 200 may be divided as the AP transmits a triggering ACK to the mobility management server 300. Here, the description of the handover of the mobile terminal 200 will be described later with reference to FIG. 4.

When the mobile terminal 200 performs handover, the packet buffering unit 350 performs buffering on a packet to be transmitted to the mobile terminal. The packet buffering execution unit 350 may perform packet buffering when the triggering ACK is generated from the handover determination unit 340.

The packet buffering unit 350 according to an embodiment of the present invention may perform packet buffering according to priority when a plurality of packets are to be handed over at the same time and thus need to be buffered. Here, the priority may be determined according to the MAC address in the MAC table as shown in Table 1, and may be determined when the MAC table is created in advance.

The packet buffering unit 350 determines the buffering order and the transmission order of the transport packet based on the priority, and may perform buffering in the order of the MAC addresses having the highest priority in the MAC table. Here, the size of the buffer for performing packet buffering may be calculated in association with the handover time of 802.11, but the selection of the calculation process may be determined according to a policy selected by those skilled in the art, and thus will be omitted.

In addition, the buffering timer informs the initialization time of the packet, which is an important factor in the packet buffering unit. If the initialization time of the buffer is not correct, the TCP sequence numbers of the packets buffered in the buffer are indistinguishably mixed, and the packets may be discarded even if they are transmitted after being buffered.

Therefore, the packet buffering execution unit 350 may calculate the size of the buffer to obtain the maximum handover time, and based on this, the initialization time of the buffering timer may be obtained. Accordingly, the buffer performs buffering under the control of the buffering timer. If no reconnection occurs from the network user until the buffered packet exceeds the reference time of the buffering timer, all packets in the buffer may be initialized.

If the mobile terminal 200 attempts to reconnect while the buffering timer is operating, the buffer may stop buffering, and the buffered packet may be transmitted to the mobile terminal 200 by the communication relay 360.

Therefore, when the mobile terminal 200 performs a handover, the mobility management server 300 buffers a packet to be transmitted to the mobile terminal 200 and stops buffering when the handover is completed, and the buffered packet is stored in the mobile terminal. By transmitting to 200, packet loss can be prevented.

The communication relay unit 360 communicates with the mobile terminal 200 and the network management center 400 using the converted physical address and IP address. When the triggering ACK is not transmitted, that is, when the handover is not performed, the communication relay unit 360 includes the translated physical address and IP address in the second and third layer headers of the transport packet and thus the network management center 400. Can be sent to.

On the contrary, when the triggering ACK is transmitted, the communication relay unit 360 transmits the buffered packet from the packet buffering unit 350 according to priority when the mobile terminal 200 attempts to reconnect when the handover is completed. It may transmit to the mobile terminal 200.

4 is a flowchart illustrating a handover procedure of a mobile terminal according to an embodiment of the present invention. Here, FIG. 4 includes a procedure performed when the mobile terminal 200 performs a handover from a currently connected AP to a new AP.

As shown in FIG. 4, the mobile terminal 200 may detect a weakness of a received signal strength indication (RSSI) in an AP to which it is currently connected, and attempt to handover to a new AP. When the RSSI becomes weak, the mobile terminal 200 transmits and receives a probe request and a probe response message, scans a new AP and receives parameter information such as beacon transmission interval, BSSID, and channel capacity of each AP in this process. .

The triggering ACK sent by the mobile terminal 200 to the AP in the scanning process may not only be a second layer message but also may inform handover. In the present invention, the mobile terminal 200 may perform a handover by transmitting a second layer triggering ACK indicating that the AP, which has received the triggering ACK, handovers to the mobility management server 300.

The mobile terminal 200 may perform a synchronization process such as timing of second and third layers and a new AP to be handed over and connect. When the connection is completed, the authentication procedure is performed through communication with the RADIUS server, and the movement of the mobile terminal 200 is notified to the previous AP (Previous AP) by transmitting and receiving an IAPP packet. Subsequently, the new AP informs whether to accept the corresponding terminal by sending an association response message, allocates resources for the mobile terminal 200 and sets an association ID when accepting.

 5 is a flowchart illustrating a mobility management method according to an embodiment of the present invention.

Referring to FIG. 5, in step S500, the physical address of the mobile terminal 200 is authenticated based on the MAC address of the predetermined mobile terminal stored in the MAC table. Here, the MAC table may be preconfigured in the process of installing the mobility management server 300 initially. In addition, the MAC table may include information such as a MAC address of a predetermined mobile terminal, a fixed IP address corresponding to the MAC address of a predetermined mobile terminal, whether a triggering ACK occurs, a destination port number, an address type, and the like. Can be.

The mobility management server 300 may accept a connection with the network management center 400 when the mobile terminal 200 has a MAC address corresponding to the MAC address registered in the MAC table.

In step S501, the physical address of the mobile terminal 200 is converted into the physical address of the mobility management server 300. The mobility management server 300 converts the source MAC address, that is, the MAC address of the mobile terminal 200, into the MAC address of the mobility management server 300 in the second layer header of the transmitted packet, so that the network management center 400 Without knowing the situation in which the handover is performed, it is possible to continuously maintain the connection with the mobile terminal 200.

In step S502, the IP address of the mobile terminal is converted into a fixed IP address corresponding to the MAC address of the predetermined mobile terminal in the MAC table. The mobility management server 300 converts the source IP address into a unique IP address by the MAC table in the third layer IP header of the transmitted packet, so that the network management center 400 converts the source IP address into the mobility management server 300. Can be recognized as). Therefore, even after the mobile terminal 200 of the network user completes the handover, the access log with the network management center 400 may be maintained.

In step S503, it is determined whether a triggering ACK for handover notification is transmitted from the AP accessing the mobile terminal 200.

As a result of the determination, when the triggering ACK indicating the handover is not transmitted, in step S504, the converted physical address and IP address may be included in the second and third layer headers of the transport packet and transmitted to the network management center 400.

On the other hand, if a triggering ACK for handover notification is transmitted as a result of the determination, in step S505, buffering of a packet to be transmitted to the mobile terminal 200 is performed. The mobility management server 300 may perform packet buffering according to priority when a plurality of packets are to be handovered at the same time and thus need to perform packet buffering. Here, the priority may be determined according to the MAC address in the MAC table as shown in Table 1, and buffering may be performed in order of the MAC addresses having the highest priority. If the mobile terminal 200 attempts to reconnect while buffering, the buffering may be stopped.

In step S506, after the mobile terminal 200 completes the handover, if the mobile terminal 200 attempts to reconnect, the packet buffered in the step S505 may be transmitted to the mobile terminal 200.

One embodiment of the present invention may also be embodied in the form of a recording medium including instructions executable by a computer, such as program modules, being executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

200: mobile terminal 210, 220: access point
230, 240: access router 250: backbone router
300: mobility management server 310: physical address authentication unit
320: physical address conversion unit 330: IP address conversion unit
340: handover determination unit 350: packet buffering execution unit
360: communication relay 400: network management center

Claims (10)

A mobility management server supporting mobility of a mobile terminal in a network management system based on a wireless communication network,
A physical address authenticator configured to authenticate a physical address of a predetermined mobile terminal based on the physical address table;
A physical address translator configured to translate a physical address of an authenticated mobile terminal into a physical address of the mobility management server;
An IP address conversion unit for converting an IP address of the authenticated mobile terminal into a fixed IP address given by the physical address table;
A communication relay unit configured to communicate with the authenticated mobile terminal and a network management center using the converted physical address and IP address;
Including, a mobility management server.
The method of claim 1,
A handover determination unit that determines whether the authenticated mobile terminal is handed over based on a triggering response message transmitted from the authenticated mobile terminal.
Further comprising, a mobility management server. The method of claim 2,
If it is determined that the handover is performed, a packet buffering unit that performs packet buffering to be transmitted to the authenticated mobile terminal
Further comprising, a mobility management server.
The method of claim 2,
The physical address table is
Mobility management including information regarding at least one of a physical address of the predetermined mobile terminal, a fixed IP address corresponding to the physical address of the predetermined mobile terminal, whether the triggering response message is generated, a destination port number, and an address type. server.
The method of claim 1,
The physical address authentication unit, the mobility management server to determine whether to access the authenticated mobile terminal by the physical address of the predetermined mobile terminal included in the physical address table.
A mobility management method for supporting mobility of a mobile terminal in a network management system based on a wireless communication network,
Authenticating the physical address of the mobile terminal based on the physical address of the predetermined mobile terminal stored in the physical address table;
Converting a physical address of the authenticated mobile terminal into a physical address of a mobility management server; and
Communicating with the mobile terminal and a network management center using the translated physical address and a fixed IP address corresponding to the translated physical address
Including, mobility management method.
The method according to claim 6,
Determining whether the mobile terminal is handed over based on a triggering response message transmitted from the mobile terminal;
If it is determined that the handover has been performed, performing packet buffering to be transmitted to the mobile terminal;
Further comprising, mobility management method.
The method of claim 7, wherein
The physical address table is
And information on at least one of a physical address of the predetermined mobile terminal, a fixed IP address corresponding to the physical address of the predetermined mobile terminal, whether the triggering response message is generated, a destination port number, and an address type. How to manage mobility.
The method according to claim 6,
In the authenticating of the physical address, determining whether to access the mobile terminal based on the physical address of the predetermined mobile terminal included in the physical address table.
The method of claim 7, wherein
Performing the packet buffering,
Perform packet buffering according to priority, wherein the priority corresponds to a physical address of the predetermined mobile terminal.

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