KR20040051329A - Hand-Over Method Between Wireless Local Area Network and Mobile Telecommunication Network - Google Patents

Abstract

PURPOSE: A handover scheme between WLAN and a mobile communication network is provided to easily provide a service by allowing a GGSN interworking at an IP level to perform a handover function. CONSTITUTION: When a mobile terminal is moved into a WLAN(Wireless Local Area Network) region from a 3GPP UTRAN region, connection between the mobile terminal and the 3GPP UTRAN(UMTS Terrestrial Radio Access Network) is maintained as it is and a wireless matching with an AP of the WLAN is set(S408). A subscriber authentication(security) is performed for a service with an AAA server(S409) and the mobile terminal puts the same APN(Access Point Name) used for identifying the service in the UTRAN region on a DHCP discover message, and broadcasts it(S410). The GGSN puts the same IP address on a DHCP providing message and transmits it to the mobile terminal(S411). The mobile terminal transmits a DHCP(Dynamic Host Configuration Protocol) request message to the GGSN(S412). The GGSN transmits a DHCP ACK message to the mobile terminal(S413), thereby completing WLAN matching connection. The mobile terminal sends a deactivate PDP context request message to the GGSN(S414). An SGSN(Serving GPRS Support Node) deletes PDP context which has been set between the SGSN and the GGSN(S415), and carries a result on a deactivate PDP context response message and transmits it to the mobile terminal(S416). A radio access bearer release message and a radio bearer release message are transmitted to an RAN(Radio Access Network) and the mobile terminal to release radio resource(S417,S418).

Description

Handover Method between Wireless LAN Network and Mobile Communication Network {Hand-Over Method Between Wireless Local Area Network and Mobile Telecommunication Network}

The present invention relates to a wireless packet service, and more particularly, to a handover scheme between a wireless LAN network and a mobile communication network suitable for easily providing a handover service at an IP level.

1 is a structural diagram according to the prior art for interworking a WLAN-UMTS (Wireless Local Area Network-Universal Mobile Telecommunication Systems) network, a packet service and a 3GPP UMTS via a wireless local area network (WLAN). The WLAN-3GPP Dual Mode / Dual Band mobile terminal 10 capable of providing packet service through the service or the UTS Terrestrial Radio through the WLAN 20 according to its location Access Network (hereinafter referred to as UTRAN) 30 may be provided with a service.

That is, when located in an area where WLAN service can be provided, the mobile terminal 10 is wirelessly matched to the WLAN 20 through an access point (hereinafter referred to as an AP) 21. 20 transmits the message requested by the mobile terminal 10 to the UMTS packet network 40 through an access router 22.

At this time, an inter-work unit (hereinafter referred to as IWU) 23 exists between the WLAN 20 and the UMTS packet network 40 so that the WLAN 20 matches the UMTS packet network 40. To be possible.

On the other hand, when the mobile terminal 10 is located in an area where WLAN service cannot be provided, it is matched to the UTRAN 30 through a Node-B (Node-B) 31, and the UTRAN 30 is mobile. The service message requested by the terminal 10 is transmitted to the UMTS packet network 40 through a radio network controller (hereinafter referred to as RNC) 32.

In addition, the UMTS packet network 40 authenticates the mobile terminal 10 requesting packet service through the UTRAN 30 using a mobile communication packet switching station (hereinafter referred to as SGSN) 41. And a packet call establishment request.

At the time of location registration, the mobile terminal 10 authenticates the subscriber by using the International Mobile Subscriber Identity (IMSI), and the SGSN 41 assigns the TMSI to the mobile terminal 10 to hide the IMSI so that the TMSI is used for subscriber verification. .

The SGSN 41 receives an PDP Context Request message containing an Access Point Name (hereinafter referred to as APN) and TMSI from the mobile terminal 10 and uses the TMSI included in the message. By using the APN to identify the subscriber to select the GGSN (42) to provide the service requested by the mobile terminal (10).

The SGSN 41 requests the IP of the GGSN 43 to provide a service to a DNS server (not shown) by using the APN. In this case, several GGSN IP addresses may be mapped to the APN. The SGSN 41 selects any GGSN IP among the multiple GGSN IPs, and includes an IMSI and an APN mapped to TMSI in a Create PDP Context Request message, indicating the selected GGSN IP. The GGSN 42 allocates an IP address to be used by the mobile terminal 10, and informs the mobile terminal 10 of the IP address allocation result through the SGSN 41.

The GGSN 42 identifies the mobile station 10 by using an interim (International Mobile Subscriber Identity (hereinafter referred to as IMSI)) number transmitted from the SGSN 41, and the GGSN 42 assigns an IP address. Then save the IP address assigned to the IMSI number. When the IP address is assigned to the mobile terminal 10, the service subscriber can use the packet service.

In the UTRAN region, packet call setup is performed using a packet session establishment procedure recommended by 3GPP.

As described above, in the WLAN-UMTS interworking scheme currently proposed, SGSN 41 is used as a matching node for WLAN-UMTS packet service, and a call processing procedure and node matching are performed using a wireless matching standard and following 3GPP UMTS packet service procedure. This structure is called a WLAN-UMTS tight coupling structure.

Currently, the WLAN handover procedure between UMTS is under standardization standard in 3GPP.

However, in the above-described prior art, the protocol conversion between WLAN and 3GPP UMTS, the IWU function development for providing the SGSN and the matching function, and the matching protocol between the IWU and the SGSN have to be newly defined. There is a costly problem in developing a function for conversion.

In addition, since the handover procedure is being standardized in 3GPP, it is expected that a lot of time is required until the handover scheme is released.

An object of the present invention is to provide a handover scheme between a WLAN network and a mobile communication network for facilitating control according to interworking between WLAN-UMTS and handover between WLAN-UTRAN. .

The handover scheme between the wireless LAN and the mobile communication network according to the present invention for achieving the above object is to receive a DHCP (Dynamic Host Configuration Protocol) discovery broadcast message containing the access point name from the mobile terminal located in the wireless LAN network Providing a service by wireless matching through a packet gateway exchange selected using the access point name, and receiving a session establishment activation request message containing an access point name from a mobile terminal handed over to the Utran region. And setting up a session with a packet gateway switch selected using the access point name included in the received message to provide a service, and performing handover from the WLAN network to the mobile communication system network.

More specifically, after establishing a session with the packet gateway switch and before providing a service, receiving a DHCP release message from the mobile terminal to notify the packet gateway switch that the radio matching has been released, the mobile in the WLAN network Handover is made to a communication system network.

The method may further include receiving a session establishment activation request message including an access point name from a mobile terminal located in a yutran region, and providing a service by setting up a session with a packet gateway exchange selected using the access point name; Receiving a DHCP discovery broadcast message containing the access point name from the mobile terminal handed over to the wireless LAN network, and wirelessly matched to the packet gateway switch selected using the access point name included in the received message Including the providing step characterized in that the handover to the Utran region in the WLAN.

More specifically, the method may further include receiving a session inactivity request message from the mobile station, deleting the session and releasing the allocated resource before providing a service after wireless matching with the selected packet gateway exchange. It is done.

1 is a network structural diagram according to the prior art for interworking WLAN-UMTS network;

2 is a network structural diagram according to the present invention for interworking WLAN-UMTS network;

3A and 3B are signal flow diagrams illustrating a handover process according to the present invention when a mobile terminal moves to a UTRAN region in a WLAN network.

4A and 3B are signal flow diagrams illustrating a handover process according to the present invention when a mobile terminal moves from a UTRAN region to a WLAN network.

Explanation of symbols for the main parts of drawings

100: mobile terminal 200: wireless LAN network

300: Utran 400: universal mobile communication packet network

500: internet network 201: access point

202: access router 301: node-B

302: wireless network controller 401: mobile communication packet switching station

402: packet gateway switching center 403: AAA server

404: DHCP server 405: HLR

406: RAN

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a diagram illustrating a network structure according to an embodiment of the present invention for interworking WLAN-UMTS networks.

WLAN-3GPP UMTS Dual Mode / Dual Band Mobile Terminal capable of providing packet service over Wireless Local Area Network (hereinafter, referred to as WLAN) and packet service over 3GPP UMTS 100 may be provided with a service through a WLAN 200 network or a service through a Utran (UMTS Terrestrial Radio Access Network: UTRAN) 300 according to its location.

That is, when the mobile terminal 100 is located in an area where the WLAN service can be provided, the mobile terminal 100 is wirelessly matched to the WLAN 200 through an access point 201. 200 transmits the message requested by the mobile terminal 100 to the packet gateway switching center (GGSN) 402 of the UMTS packet network 400 through an access router (202).

On the other hand, when the mobile terminal 100 is located in an area where WLAN service cannot be provided, it is matched to Utran (hereinafter referred to as UTRAN) 300 through a Node-B (Node-B) 301. The UTRAN 300 transmits a service message requested by the mobile terminal 100 to the UMTS packet network 400 through a wireless network controller (hereinafter referred to as RNC) 302.

In the UMTS packet network 400, the mobile station 100 requests a packet service through the UTRAN 300 using a mobile communication packet switching station (hereinafter referred to as SGSN) 401. Performs registration and processing of authentication and packet call requests.

When the SGSN 401 receives the PDP Context Activation Request message including TMSI and APN from the mobile terminal 100, the SGSN 401 identifies the subscriber using the TMSI included in the received message and uses the APN. The mobile terminal 100 selects the GGSN 402 to provide the service requested.

The SGSN 401 queries the APN for a DNS server (not shown) and requests the IP of the GGSN 402 to provide a service to the mobile terminal 100. In this case, the GGSN IP address corresponding to the APN is previously known. Although several may be mapped, in the case of an APN interworking with a WLAN network, the DNS server maps only one GGSN IP address to the APN so that one GGSN IP can be obtained using the APN.

The SGSN 401 receiving the GGSN IP from the DNS server transmits the IMSI and APN mapped to the TMSI to the GGSN 402 indicated by the GGSN IP in a PDP Context Request message. ) Allocates an IP address to use and notifies the mobile station 100 of the IP allocation result through SGSN 401.

In this case, the GGSN 402 may assign authentication / billing / authorization and IP address to the mobile terminal 100 by using additional devices such as the AAA server 403 and the DHCP server 404 as necessary.

As described above, the present invention has no configuration of an IWU node, which is a node for interworking between WLAN and UMTS packet networks, and uses GGSN instead of SGSN as a matching node for WLAN-UMTS packet service.

As such, the structure of the present invention, which achieves matching through GGSN, which is a node managing / allocating IP, is called a WLAN-UMTS interworking scheme or an IP coupling structure in the IP layer.

Next, a handover scheme according to the present invention will be described.

3A and 3B are signal flow diagrams illustrating a handover process according to the present invention when a mobile terminal moves from a WLAN region to a UTRAN region, and FIGS. 4A and 4B illustrate a mobile terminal moving from a UTRAN region to a WLAN region. In this case, the signal flow shows the handover process according to the present invention.

3A and 3B, and FIGS. 4A and 4B are continuous views, and thus description will be made without separate classification.

As shown in FIGS. 3A and 3B, after a service subscriber requesting a packet service through a WLAN network performs wireless matching using the dual mode / dual band mobile terminal 10 (802.11 association request) (S301), (802.11 association response) (S302), AAA server (403) and subscriber authentication (Security) for the service (S303) and DHCP discovery message (DHCP DISCOVER) with multiple GGSNs interworking in the same General Packet Radio Service (GPRS) network Send an IP address request (S304).

At this time, a user ID (USER ID) for identifying a mobile station in the DHCP DISCOVER message and an access point name (Access Point Name: hereinafter referred to as APN) used in a 3GPP UMTS packet network to identify a service. ) And transmit it by the method of broadcasting.

The GGSNs 402 that have received the DHCP Discover message (DHCP DISCOVER), if the APN included in the DHCP Discover message (DHCP DISCOVER) is an identifier indicating itself, the mobile terminal 100 as a DHCP OFFER (DHCP OFFER). (S305), if the APN is not an identifier indicating itself, the received DHCP Discover message (DHCP DISCOVER) is ignored.

Accordingly, the mobile terminal 100 sends a DHCP request message (DHCP REQUEST) to the corresponding GGSN (402) to inform that the specific GGSN is selected (S306).

Subsequently, the selected GGSN 402 obtains an IP address to be allocated to the mobile terminal 100 using the user ID, and assigns the IP address to the mobile terminal 100 by placing the IP address in a DHCP ACK message. (S307).

The mobile terminal 100 assigned the IP address may receive a packet service through the WLAN network (S308).

As such, when the mobile terminal 100 receiving the packet service through the WLAN network moves to the 3GPP UTRAN region, the mobile terminal 100 requests a service through a 3GPP UMTS packet call setup procedure.

In this case, the mobile terminal 100 transmits an PDP Context Activation Request message (S309) to the SGSN 401 (S309), which was used to identify a service in the WLAN network in the PDP Context Activation Request message. By transmitting the same APN as the APN, the same GGSN is selected in the 3GPP UTRAN area as in the WLAN network.

Subsequently, a radio access bearer is established between the SGSN 401 and a radio access network (RAN) 406 (S310), and a radio bearer is established between the RAN 406 and the mobile terminal 100. At step S311, the GGSN 13 determines whether to accept the requested PDP context, and if it is accepted, the GGSN 13 has the same IP address as the PDP context creation message (Create PDP Context) (S312). The mobile station 100 allocates the mobile terminal 100 to the mobile terminal 100 through an PDP context activation accept message (S313).

The GGSN 402 knows that the mobile terminal 100 is receiving a service through the WLAN, and the mobile terminal 100 releases the WLAN registration as it moves to the UTRAN 300 area. If the GGSN 402 is informed via the DHCP RELEASE message (DHCP RELEASE) with the user ID (100) (S314), packet transmission / reception is performed through the 3GPP UMTS network (S315).

On the contrary, as shown in FIGS. 4A and 4B, the mobile terminal 100 accesses an access point name (hereinafter abbreviated as APN) and a traffic channel requested by the user in order to receive a packet service. Bearer information (Bandwidth) is specified, and these are included in an PDP Context Activation Request message (S401) and transmitted to the SGSN 12 through the base station.

The SGSN 401 receiving the PDP Context Activation Request message selects one GGSN 402 using the APN included in the message.

Thereafter, a radio access bearer is established between the SGSN 401 and the radio access network (RAN) 406 (S402), and a radio bearer between the RAN 406 and the mobile terminal 100 is established. If set (S403), the SGSN 401 creates a PDP context with the selected GGSN 402 (Create PDP Context) (S404).

Subsequently, the SGSN 401 is assigned an appropriate IP address from the GGSN 402 and transmits the IP address to the mobile terminal 100 in the PDP Context Activation Accept message (S405).

As such, when the IP address is assigned to the mobile terminal 100, the mobile terminal 100 may receive a packet service through the UMTS network (S406).

As such, when the mobile terminal 100 receiving the packet service in the 3GPP UTRAN region moves to the WLAN region, the mobile terminal 100 wirelessly maintains the connection with the 3GPP UTRAN while maintaining the connection with the AP 201 of the WLAN 200 network. The registration is set (802.11 association request) (S407), (802.11 association response) (S408).

Subsequently, after AAA server 403 and subscriber security (S409) for the service, the access point name (APN) used to identify the service in the UTRAN area in the DHCP DISCOVER (S410). Contains the same APN as and transmits it by the method by broadcasting.

Accordingly, the GGSN 402 indicated by the APN transmits the same IP address to the mobile terminal 100 in the DHCP OFFER (DHCP OFFER) with the same IP address allocated to the service in the 3GPP UTRAN region (S411). The APN is the same APN as the APN used to identify the service in the UTRAN region, and the GGSN selected using the APN is also the same as the GGSN providing the service in the UTRAN region.

In addition, the mobile terminal 100 sends a DHCP request message (DHCP REQUEST) (S412) to the GGSN 402, and the GGSN 402 responds to the mobile terminal 100 with a DHCP Ack message (DHCP ACK) (S413). The WLAN match connection is complete.

Subsequently, a procedure of releasing a resource connected through a 3GPP UMTS packet network is performed. When the mobile terminal 100 sends a Deactivate PDP Context Request message (S414) to the GGSN 402, the SGSN 401 transmits a PDP Context Request. Delete the PDP context set up with the GGSN (402) (Delete PDP Context) (S415), and transfer the result to the PDP Context Deactivation Response message (Deactivate PDP Context Response) (S416) to the mobile terminal 100 Deactivate the session you set up for service in the Utran area.

Subsequently, a radio resource access release message (Radio Access Bearer Release) (S417) and a radio resource release message (Radio Bearer Release) are transmitted to the Radio Access Network (RAN) 406 and the mobile terminal (MS) 100. The wireless resource is released by transmitting (S418).

Through the above process, handover is performed between the WLAN network and the UTRAN region.

The handover scheme between the wireless LAN network and the mobile communication network of the present invention as described above provides a handover function in the GGSN interworking at the IP level, thereby providing a simpler service and minimizing modifications to the existing WLAN and 3GPP UMTS packet networks. It can be effected.

In addition, the use of the access point name can solve the security problem of IP address exposure of the packet gateway exchange over the air.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (4)

Receiving a DHCP (Dynamic Host Configuration Protocol) discovery broadcast message including an access point name from a mobile station located in a wireless LAN network; Providing a service by wireless matching through a packet gateway exchange selected using the access point name; Receiving a session establishment activation request message containing an access point name from a mobile terminal which has handed over to the Utran region; Wireless LAN network and mobile, characterized in that the handover is made from the WLAN network to the mobile communication system, including providing a service by establishing a session to the packet gateway switch selected using the access point name included in the received message Handover between communication networks. The method of claim 1, After establishing a session with the packet gateway exchange and before providing a service, Receiving a DHCP release message from the mobile terminal and notifying the packet gateway exchange that the radio matching has been released, wherein the handover between the wireless LAN network and the mobile communication network is performed. Over scheme. Receiving a session establishment activation request message including an access point name from a mobile terminal located in a yutran region; Providing a service by establishing a session with a packet gateway exchange selected using the access point name; Receiving a DHCP discovery broadcast message containing the access point name from a mobile terminal handed over to a wireless LAN network; A wireless LAN network and a mobile communication network characterized in that a handover is performed from a WLAN network to a Utran region, including providing a service by wirelessly matching to a packet gateway exchange selected using an access point name included in a received message. Handover Scheme. The method of claim 3, wherein Before providing a service after wireless matching with the selected packet gateway exchange, And receiving the session inactivity request message from the mobile terminal, deleting the session, and releasing the allocated resources.