KR100824461B1 - Device and method of maintenance ip on the wireless telecommunication system during data hand-off - Google Patents

Abstract

The present invention relates to an apparatus for maintaining IP during data handoff in a mobile communication system and a method thereof. In particular, the method of the present invention provides an IP for a wireless data communication service in a PDSN or a GGSN to a mobile terminal located in a CDMA network or a WCDMA network. To provide wireless data service, and when the mobile station moves from the mobile terminal to the WCDMA network or the CDMA network, the previously mobile IP address is transferred to the mobile GGSN or PDSN. If there is a PPP session remaining in the GGSN, open the data packet call path with the PDSN or GGSN before the relocation in the relocated GGSN or PDSN, and then through the PDSN or GGSN before relocation in the relocated GGSN or PDSN It connects to an internet server through a gateway to provide a wireless data communication service to a mobile terminal. Therefore, the present invention continuously maintains an IP address assigned to a mobile terminal even when data is handed off between a CDMA network and a WCDMA network (or between CDMA networks) so that wireless data communication services such as online games with an Internet server are seamlessly interrupted. It can provide and replace the scarce IP resources of the mobile communication system, thereby saving the IP resources.

CDMA, WCDMA, Data Handoff, IP

Description

Device and method for maintaining IP during data handoff in mobile communication system {DEVICE AND METHOD OF MAINTENANCE IP ON THE WIRELESS TELECOMMUNICATION SYSTEM DURING DATA HAND-OFF}

1 is a block diagram schematically illustrating an IP holding apparatus at the time of data handoff in a mobile communication system according to an embodiment of the present invention;

2 is a flowchart sequentially illustrating a method for maintaining an IP during data handoff in a mobile communication system according to an embodiment of the present invention;

3 is a block diagram schematically illustrating an IP holding apparatus at the time of data handoff in a mobile communication system according to another embodiment of the present invention;

4 is a flowchart sequentially illustrating a method for maintaining an IP during data handoff in a mobile communication system according to another embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

10, 90: mobile terminal 20: base station (BTS)

30: base station controller (BSC) 40: PDSN

50: GGSN 60: SGSN

70: RNC 80: wireless repeater

100: Gateway 110: Internet Server

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and in particular, a mobile communication system capable of saving IP resources while preventing disconnection of a wireless data communication service by maintaining an IP allocated for wireless data communication even when a mobile terminal moves its location. An apparatus and method for maintaining an IP at the time of data handoff in the present invention.

Currently, wireless data services using mobile terminals are diversifying and increasing in mobile communication systems.

Internet Protocol (IP) addresses are required for wireless data services of mobile terminals, but 32-bit IPv4 with up to 12 digits (for example 210.113.39.224) is limited to meet the exponentially growing demand for Internet addresses. There is.

That is, in a wireless network environment using IPv4, a public IP pool assigned by a mobile carrier is limited, and thus a fixed IP that can be allocated to a mobile terminal, that is, a mobile IP is limited.

In the high-speed data service environment such as EVDO, WCDMA, etc., the up / down bandwidth of the mobile terminal increases as time goes by, and the capacity and computing performance of the mobile terminal itself continue to develop, so that the mobile terminal physically moves, The demand for fixed IPs, or mobile IPs, which can serve as servers with fixed IP (FTP, TELNET, HTTP, etc.) is also increasing.

In addition, in case of accessing the online game server through wireless data communication through the mobile terminal, even if the location of the mobile terminal moves, the IP assigned to the terminal must be fixed so that the online game server can be continuously online without disconnection (or forced logout). You can enjoy the game.

Therefore, in the wireless data communication environment according to the prior art, a new IP should be assigned to the mobile terminal when the location of the mobile terminal moves and data is handed off between the PDSN network or between the PDSN network and the GGSN network. Since the public IP pool allocated by the mobile communication provider is limited, there is a limit to satisfy the increasing demand of the Internet IP address of the mobile terminal, and there is a problem that wireless data communication of the mobile terminal is interrupted in the process of newly assigning IP.

An object of the present invention is to save the IP resources while preventing the disconnection of the wireless data communication service by proceeding wireless data communication over the already assigned IP even if the mobile terminal moves the location in order to solve the problems of the prior art as described above The present invention provides an apparatus for maintaining an IP when data is handed off in a mobile communication system.

Another object of the present invention is to provide a data hand in a mobile communication system capable of saving IP resources while preventing the disconnection of a wireless data communication service by maintaining the IP allocated for wireless data communication even when the mobile terminal moves its location. It is to provide an IP maintenance method when off.

In order to achieve the above object, the present invention provides a mobile communication system for providing wireless data communication of an Internet server to a mobile terminal, wherein the mobile station is connected through a base station of a CDMA network to allocate an IP for a wireless data communication service. And a GGSN connected to a mobile terminal through a wireless repeater of a WCDMA network to allocate an IP for a wireless data communication service, and a gateway connecting to an Internet server through an IP assigned from a PDSN or GGSN. When relocating to a CDMA network or WCDMA network, a data packet call path with a PDSN or GGSN before relocating from the relocated GGSN or PDSN using the previously assigned IP is opened, and the gate passes through the PDSN or GGSN before relocation. It is characterized in that the connection to the Internet server via the way.

In order to achieve the above object, another apparatus of the present invention is a mobile communication system for providing wireless data communication of an Internet server to a mobile terminal, wherein the mobile terminal is connected through a base station of a CDMA network to provide an IP for a wireless data communication service. A first PDSN to be allocated, a second PDSN connected to another mobile station in the CDMA network to allocate an IP for a wireless data communication service, and a gateway for accessing the Internet server through the first PDSN or the IP assigned to the second PDSN. When the mobile terminal is moved between the CDMA network by opening a data packet call path with the second PDSN or the first PDSN relocated using the previously assigned IP in the first PDSN or the second PDSN or the first PDSN before the position movement or And connect to the Internet server through the gateway via the second PDSN.

In order to achieve the above object, the present invention provides a method for servicing wireless data communication of an Internet server to a mobile terminal, comprising: IP for wireless data communication service in a PDSN or GGSN to a mobile terminal located in a CDMA network or a WCDMA network. Providing a wireless data service by allocating a mobile station, and transmitting a previously allocated IP address to a GGSN or PDSN, which has been previously assigned by the mobile device, when the mobile station moves to a WCDMA network or a CDMA network. Opening a data packet call path with the PDSN or GGSN before relocating in the relocated GGSN or PDSN if there is a PPP session remaining in the PDSN or GGSN prior to Wireless data communication services by accessing Internet servers through gateways via PDSN or GGSN A comprises the step of providing to the mobile terminal.

In order to achieve the above object, the present invention provides a method for servicing wireless data communication of an internet server to a mobile terminal, and assigning an IP for wireless data communication service in a first PDSN or a second PDSN to a mobile terminal located in a CDMA network. Providing a wireless data service, transmitting a previously allocated IP address to the second PDSN or the first PDSN, which has been previously moved by the mobile terminal when the mobile terminal is moved between CDMA networks; Opening a data packet call path with the first PDSN or the second PDSN before the location shift in the relocated second PDSN or the first PDSN if there is a PPP session remaining in the first PDSN or the second PDSN; Connect to the Internet server through the gateway via the 1PDSN or the 2PDSN before the location shift in 1PDSN. Providing the wireless data communication service to the mobile terminal.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

1 is a block diagram schematically illustrating an apparatus for maintaining an IP when data handoff is performed in a mobile communication system according to an embodiment of the present invention. An embodiment of the present invention provides a data hand of a mobile terminal between a CDMA network and a WCDMA network. For example, off.

As shown in FIG. 1, the IP holding apparatus for data handoff in a mobile communication system according to an embodiment of the present invention includes a mobile station 10, 90, a base station / base station controller (BTS / BSC), which is a CDMA network ( 20, 30) and a Packet Data Serving Node (PDSN) 40, a Gateway GPRS Support Node (GGSN) 50, a Serving GPRS Support Node (SGSN) 60, and a Radio Network Controller (RNC) 70, which are WCDMA networks. , A wireless repeater 80, a gateway 100, an internet server 110, and the like.

The mobile terminal 10 is in the range of the base station (BTS) 20 in the CDMA network, and the terminal information is transmitted to the PDSN 40 via the base station / base station controller (BTS / BSC) 20, 30, and the PDSN ( The information transmitted from 40 is transmitted to the mobile terminal 10 via a base station controller / base station (BSC / BTS) 30. The moved mobile terminal 90 is within the range of the wireless instrument 80 in the WCDMA network, and transmits the terminal information to the GGSN 50 via the radio repeater / RNC / SGSN 80, 70, 60, The information transmitted from the GGSN 50 is transmitted to the mobile terminal 90 through the SGSN / RNC / wireless repeaters 60, 70, and 80.

The base station (BTS) 20 connects the mobile terminal 10 to the PDSN 40, performs wireless communication with the mobile terminal 10, and performs wired / wireless conversions to communicate with the base station controller (BSC) 30 by wire. Perform the function.

The PDSN 40 connects a wireless signal to the gate weight 100 through interworking between a base station system (BSS) consisting of a base station / base station controller (BTS / BSC) 20 and 30 and a data core network (DCN). However, by assigning an IP for wireless data communication, the mobile terminal 10 of the CDMA network, which is a mobile subscriber using Point-to-Point Protocol (PPP) and Transmission Control Protocol / Internet Protocol (TCP / IP) protocol, may be Wireless data communication with the Internet server 110 is performed.

When the GGSN 50 receives a packet data initiation request through the SGSN 60, the GGSN 50 allocates a temporary IP address that can be used only within GPRS to the corresponding user, and changes the transmitted packet to a global IP address so that the gate weight can be changed. By connecting to (100), the mobile terminal 90 of the mobile communication subscriber WCDMA network performs wireless data communication with any Internet server 110.

The PDSN 40 and the GGSN 50 according to the present invention store node IP address information of a network different from the current network when the IP is assigned. The mobile terminal 10 or 90 then moves from the PDSN 40 network to the GGSN 50, or from the GGSN 50 to the PDSN 40, i.e., from the CDMA network to the WCDMA network. Before the mobile terminal 10 or 90 moves by sending a data call message to the previously assigned IP information (i.e., IP address) to the PDSN 40 or GGSN 540 to which the (10, 90) has moved. (40) or determine whether there is a PPP session as a data link in the GGSN 50, and if there is a PPP session, the previous PDSN / GGSN (40, 50) and the moved GGSN / PDSN (50, 40) and Wireless data by connecting to the gateway 100 through the PDSN / GGSN (40, 50) before moving from the GGSN / PDSN (50, 40) moved using the previously allocated IP information. Communicate

The SGSN 60 is a node in charge of data packet delivery within a service area and has functions such as packet routing and transmission, mobility management, logical link management, authentication, and charging.

The RNC 70 is composed of a wireless repeater (NODE-B) 80 and a radio network controller (RNC), and services for access to public switched telephone networks and the Internet, roaming, transparent connections, and data and web connections. It includes quality management.

The gateway 100 interprets the request using the WAP protocol of the PDSN 40 and the GGSN 50, converts the request into a TCP / IP-based request, and transmits the request to the Internet server 110, and the TCP transmitted from the Internet server 110. It converts / IP based information into WAP protocol and transmits it to PDSN 40 and GGSN 50.

Therefore, the IP holding apparatus at the time of the data handoff in the mobile communication system according to the embodiment of the present invention, IP in the mobile terminal (10, 90) through the PDSN (40) of the CDMA network or the GGSN (50) of the WCDMA network When the mobile terminal 10 or 90 is connected to the gateway 100 to provide a wireless data communication service, the mobile terminal 10 or 90 moves from the PDSN 40 to the GGSN 50 or the GGSN 50 to the PDSN 40. If a data handoff occurs, a data call path between the previous PDSN / GGSN (40, 50) and the moved GGSN / PDSN (50, 40) is opened, and the moved GGSN / PDSN (50) is transferred using the previously allocated IP information. The wireless data communication is performed by connecting to the gateway 100 through the PDSN / GGSN (40, 50) before moving in, 40).

Therefore, the apparatus according to the present embodiment continuously maintains a simple IP address, which is a dynamic IP address assigned to the mobile terminals 10 and 90, even when data is handed off between the CDMA network and the WCDMA network through the gateway 100. Wireless data communication services such as online games with the Internet server 110 are seamlessly provided.

2 is a flowchart sequentially illustrating a method of maintaining an IP during data handoff in a mobile communication system according to an exemplary embodiment of the present invention.

1 and 2, in the mobile communication system according to an embodiment of the present invention, a method for maintaining IP when data is handed off between a CDMA network and a WCDMA network is as follows.

First, when the mobile terminal 10 requests a wireless data communication service, a traffic channel is established through a base station / base international controller (BTS / BSC) 20 and 30 of a CDMA network, and a PPP is transmitted to the PDSN 40. Set a simple IP address (for example, IPv4) that is a floating IP address. (S10)

The PDSN 40 stores the IP address assigned to its node and at the same time stores the IP address of the GGSN 50 of the WCDMA network (S20).

The PDSN 40 connects to the gateway 100 using the assigned IP address and connects to the Internet server 110. The server 110 transmits packet data such as an online game to the mobile terminal 10 through the gateway 100 and the PDSN 40 to provide a wireless data communication service (S30).

If the mobile terminal 10 moves the location 90 to the WCDMA network during the wireless data communication through the PDSN 40 to generate a data handoff, the mobile terminal 90 moved to the wireless relay 80. In step S40, a traffic channel is established through the RNC / SGSN 70 and 60, and the GGSN 50 negotiates a session establishment for PPP establishment.

The mobile terminal 90 transmits the previously assigned IP address to the GGSN 50 through the radio repeater 80 and the RNC / SGSN 70 and 60, and the GGSN 50 transmits the previously assigned IP address. In step S50, a message for opening a data packet call path is transmitted from the IP address of the other PDSN to the PDSN 40 of the data handoff target.

The PDSN 40 receiving the message searches for a PPP session using the MIN number of the mobile terminal 90 and the previously assigned IP address and determines whether there is a PPP session corresponding to the corresponding IP address.

As a result of the S60 determination, if there is a PPP session with the previously allocated IP address, the PDSN 40 opens a data packet call path by sending a success message to the GGSN 50 of the WCDMA network where the mobile terminal 90 moves. S70)

The mobile terminal 90 is connected to the gateway 100 via the wireless repeater 80, the RNC / SGSN 70, 60, the GGSN 50, and the PDSN 40 that has created the data packet call path. The server 110 is connected. And, the mobile terminal through the gateway 100, PDSN (40), GGSN (50), SGSN (60), RNC (70) and wireless repeater (80) for packet data, such as online games of the Internet server 110 It transmits to the 90 to provide a wireless data communication service (S80).

If, as a result of the S60 determination, if the PPP idle timer has elapsed for more than a preset time (for example, 6 minutes) and the PPP session of the previously allocated IP address is not deleted, the PDSN 40 may determine the GGSN (50) of the WCDMA network. Send a reject message and assign a new simple IP address (eg, IPv4) by setting PPP (S90).

The mobile terminal 90 is connected to the gateway 100 through the wireless repeater 80, the RNC / SGSN 70, 60, and the GGSN 50 to access the Internet server 110. Then, packet data such as an online game of the Internet server 110 is transmitted to the mobile terminal 90 through the gateway 100, the GGSN 50, the SGSN 60, the RNC 70, and the wireless repeater 80. To provide a wireless data communication service.

Therefore, the method according to an exemplary embodiment of the present invention maintains a simple IP address, which is a floating IP address assigned to the mobile terminals 10 and 90, even when data is handed off between the CDMA network and the WCDMA network. The terminal 10, 90 provides a wireless data communication service such as an online game with the Internet server 110 through the gateway 100 without interruption.

Meanwhile, in the exemplary embodiment of the present invention, only the data handoff in which the mobile terminal is moved from the CDMA network to the WCDMA network has been described. However, even when the data handoff is performed from the WCDMA network to the CDMA network, the GGSN is used by using the IP address of the GGSN. Opens a data packet call path from the PDSN to the gateway and the Internet server via the GGSN to provide wireless data communication services.

FIG. 3 is a block diagram schematically illustrating an IP holding apparatus at the time of data handoff in a mobile communication system according to another embodiment of the present invention. Another embodiment of the present invention provides a data hand of a mobile terminal between a CDMA network and a CDMA network. For example, off.

As shown in FIG. 3, the IP holding apparatus at the time of data handoff in the mobile communication system according to another embodiment of the present invention includes the mobile terminals 200 and 270 and the first base station / base station controller (BTS / BSC) ( 210, 220, first PDSN (PDSN # 1) 230, second PDSN (PDSN # 2) 240, second base station / base station controller (BTS / BSC) 250, 260, gateway 280, Internet server 290 and the like. In the configuration of the present embodiment will be omitted for the same components as the embodiment.

The apparatus according to another embodiment of the present invention stores node IP address information of a network different from itself when IP is allocated in the first PDSN (PDSN # 1) 230 and the second PDSN (PDSN # 2) 240. The mobile terminal 200, 270 then moves from the first PDSN (PDSN # 1) 230 to the second PDSN (PDSN # 2) 240 or from the second PDSN (PDSN # 2) 240 to the first PDSN (PDSN # 1). IP information previously assigned to the first PDSN (PDSN # 1) 230 or the second PDSN (PDSN # 2) 240 moved by the mobile terminal 200 or 270 when the data handoff moves to the location 230. That is, before the mobile terminal 200 or 270 moves by transmitting a data call message to the IP address), the data link is transmitted to the first PDSN (PDSN # 1) 230 or the second PDSN (PDSN # 2) 240. Determine if there is a PPP session remaining, and if there is a PPP session open, open a data packet call path between the previous first PDSN (PDSN # 1) / second PDSN (PDSN # 2) 230, 240 and the moved PDSN, and assign Using the IP information, the mobile station connects to the gateway 280 through the PDSN before moving from the moved PDSN to provide a wireless data communication service with the Internet server 290.

Therefore, the IP holding apparatus at the time of the data handoff in the mobile communication system according to another embodiment of the present invention uses a simple IP address, which is a floating IP address allocated to the mobile terminals 200 and 270, to the data hand of the CDMA network and the CDMA network. By continuously maintaining even when off, the gateway 280 provides a wireless data communication service such as an online game with the Internet server 290 without interruption.

4 is a flowchart sequentially illustrating a method for maintaining IP during data handoff in a mobile communication system according to another embodiment of the present invention.

3 and 4, in the mobile communication system according to another embodiment of the present invention, a method for maintaining IP when data is handed off between a CDMA network and a CDMA network is as follows.

First, when the mobile terminal 200 requests a wireless data communication service, a traffic channel is established through the first base station / base international controller (BTS / BSC) 210 and 220, and the first PDSN (PDSN # 1) 230 is transmitted. PPP is set to allocate a simple IP address (eg, IPv4), which is a floating IP address (S200).

The first PDSN (PDSN # 1) 230 stores the IP address assigned to its node and at the same time stores the IP address of the second PDSN (PDSN # 2) 240 (S210).

The first PDSN (PDSN # 1) 230 connects to the gateway 280 using the assigned IP address and connects to the Internet server 290. In addition, packet data such as an online game of the Internet server 290 is transmitted to the mobile terminal 200 through the gateway 280 and the first PDSN (PDSN # 1) 230 to provide a wireless data communication service. )

If the mobile terminal 200 moves the location 270 during the wireless data communication through the first PDSN (PDSN # 1) 230 to generate a data handoff, the mobile terminal 270 that has moved is moved to the second location. A traffic channel is established through a base station / base international controller (BTS / BSC) 260 and 250, and a PPP is set to a second PDSN (PDSN # 2) 240 to request negotiation of session establishment (S230).

The moved mobile terminal 270 transmits the previously assigned IP address to the second PDSN (PDSN # 2) 240 through the second base station / base international controller (BTS / BSC) 260 and 250, and the second PDSN ( PDSN # 2) 240 sends a message for opening a data packet call path from the IP address of another PDSN to the first PDSN (PDSN # 1) 230 of the data handoff target based on the previously assigned IP address. (S240)

The first PDSN (PDSN # 1) 230 receiving the message searches for the PPP session with the MIN number of the mobile terminal 270 and the previously assigned IP address to determine whether there is a PPP session remaining corresponding to the IP address. (S250)

As a result of the determination of S250, when there is a PPP session of the previously allocated IP address, the first PDSN (PDSN # 1) 230 sends a success message to the second PDSN (PDSN # 2) 240 where the mobile terminal 270 is moved. Open the data packet call path by sending (S260).

The mobile terminal 270 has a second base station / base international flag (BTS / BSC) 260, 250, a second PDSN (PDSN # 2) 240, and a first PDSN (PDSN # 1) (FIG. It is connected to the gateway 280 via 230 to access the Internet server 290. Then, the packet data such as the online game of the Internet server 290 is transferred to the gateway 280, the first PDSN (PDSN # 1) 230, the second PDSN (PDSN # 2) 240, the second base station / base international controller ( BTS / BSC) to the mobile terminal 270 through the (260, 250) to provide a wireless data communication service (S270).

If, as a result of the determination of S250, if the PPP idle timer has elapsed for more than a predetermined time (for example, 6 minutes) and the PPP session of the previously allocated IP address is not deleted and remains, the first PDSN (PDSN # 1) 230 A reject message is sent to the second PDSN (PDSN # 2) 240, and PPP is set to allocate a new simple IP address (e.g., IPv4) (S280).

The mobile terminal 270 is connected to the gateway 280 through the second base station / base international flag (BTS / BSC) 260, 250 and the second PDSN (PDSN # 2) 240 to access the Internet server 290. do. Then, the packet data such as the online game of the Internet server 290 is transferred through the gateway 280, the second PDSN (PDSN # 2) 240, and the second base station / base international flag (BTS / BSC) 260 and 250. It transmits to the mobile terminal 270 to provide a wireless data communication service (S290).

Therefore, the method according to another embodiment of the present invention is a mobile terminal (e.g., a mobile terminal 200, 270), which is a floating IP address assigned to the mobile terminal (200, 270) continuously maintained even during data handoff between CDMA networks. The wireless data communication service such as an online game with the Internet server 290 is provided to the 200 and 270 through the gateway 280 without interruption.

As described above, the present invention moves to a previous PDSN / GGSN when a data handoff occurs in which a mobile terminal moves from a PDSN to a GGSN (or another PDSN) or from a GGSN to a PDSN (or another PDSN). Opens a data call route with the GGSN / PDSN which has been established, and provides wireless data communication service with the Internet server by connecting to the gateway through the PDSN / GGSN before moving from the moved GGSN / PDSN using the previously allocated IP information. .

Therefore, the present invention continuously maintains the IP address assigned to the mobile terminal even during data handoff between the CDMA network and the WCDMA network (or between the CDMA networks) to seamlessly disconnect wireless data communication services such as online games with an Internet server. to provide. In addition, the present invention can replace the scarce IP resources of the mobile communication system, thereby saving IP resources.

On the other hand, the present invention is not limited to the above-described embodiment, various modifications are possible by those skilled in the art within the spirit and scope of the present invention described in the claims to be described later.

Claims (10)

In the mobile communication system for providing wireless data communication of the Internet server to the mobile terminal, A PDSN connected to the mobile terminal through a base station of a CDMA network and allocating an IP for the wireless data communication service; A GGSN connected to the mobile terminal through a wireless repeater of a WCDMA network to allocate an IP for the wireless data communication service; A gateway connecting to the Internet server through an IP assigned by the PDSN or the GGSN, When the mobile station moves to the CDMA network or the WCDMA network, the mobile station opens a data packet call path with the PDSN or GGSN before moving the location by using the IP allocated from the location-based GGSN or the PDSN. IP maintenance apparatus in the case of data handoff in a mobile communication system connecting to the Internet server through the gateway via a previous PDSN or GGSN. The method of claim 1, The location-oriented GGSN or PDSN opens a data packet call path when there is a PPP session connected to the gateway at the PDSN or GGSN before the mobile terminal is moved. IP retention device on off. The method of claim 1, The mobile GGSN or PDSN is connected to the gateway by allocating a new IP when there is no PPP session connected to the gateway in the PDSN or GGSN before the mobile terminal is moved. IP retention device upon data handoff in the system. A method for servicing wireless data communication of an Internet server to a mobile terminal, Providing the wireless data service by allocating an IP for the wireless data communication service in a PDSN or a GGSN to the mobile terminal located in a CDMA network or a WCDMA network; When the mobile station moves from the mobile terminal to a WCDMA network or a CDMA network, transmitting the previously allocated IP address from the mobile terminal to the mobile GGSN or PDSN; Opening a data packet call path from the relocated GGSN or PDSN to the relocating PDSN or GGSN if there is a PPP session remaining in the relocating PDSN or GGSN; Providing the wireless data communication service to the mobile terminal by accessing the Internet server through a gateway via a PDSN or GGSN before the location movement in the location-shifted GGSN or PDSN; IP holding method during data handoff in a mobile communication system comprising a. The method of claim 4, wherein The method, If there is no PPP session in the PDSN or GGSN before the location movement, the IP address is allocated from the moved GGSN or PDSN and connected to the Internet server through the gateway to provide the wireless data communication service to the mobile terminal. The method of claim 1, further comprising the step of performing an IP handoff in a mobile communication system. In the mobile communication system for providing wireless data communication of the Internet server to the mobile terminal, A first PDSN connected to the mobile terminal through a base station of a CDMA network and allocating an IP for the wireless data communication service; A second PDSN connected to the mobile terminal through another base station of a CDMA network and allocating an IP for the wireless data communication service; A gateway for accessing the Internet server through an IP assigned by the first PDSN or the second PDSN, When the mobile station moves between the CDMA networks, a data packet call path is opened with the second PDSN or the first PDSN moved using the previously allocated IP from the first PDSN or the second PDSN to transfer the first location before the location move. IP holding apparatus in a mobile communication system for accessing the Internet server through the gateway via a 1PDSN or the second PDSN. The method of claim 6, The 2PDSN or 1PDSN, which is moved, opens a data packet call path when there is a PPP session connected to the gateway at the 1PDSN or 2PDSN before the mobile station moves. IP maintenance device at data handoff in the network. The method of claim 6, The 2PDSN or 1PDSN, which is moved, allocates a new IP and connects to the gateway when there is no PPP session connected to the gateway to the 1PDSN or 2PDSN before the mobile terminal moves. IP holding apparatus at the time of data handoff in a mobile communication system. A method for servicing wireless data communication of an Internet server to a mobile terminal, Providing the wireless data service by allocating an IP for the wireless data communication service in a first PDSN or a second PDSN to the mobile terminal located in a CDMA network; Transmitting the previously allocated IP address to the second PDSN or the first PDSN that has been moved by the mobile terminal when the mobile terminal is moved between the CDMA networks; Opening a data packet call path from the relocated 2PDSN or 1PDSN with the 1PDSN or 2PDSN before relocating if there is a PPP session remaining in the 1PDSN or 2PDSN before relocating; Providing the wireless data communication service to the mobile terminal by accessing the Internet server through a gateway through the first PDSN or the second PDSN before the location movement in the second PDSN or the first PDSN. IP holding method during data handoff in a mobile communication system comprising a. The method of claim 9, The method, If there is no PPP session in the first PDSN or the second PDSN before moving to the location, the IP address is allocated from the moved second PDSN or the first PDSN to access the Internet server through the gateway to provide the wireless data communication service. The method of claim 1, further comprising providing a mobile terminal.

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