KR20030065232A - The Structure of Complex Mobile Equipment and its Call Flow to support Seamless Handover between WCDMA and W-LAN Networks - Google Patents

Abstract

PURPOSE: An integrated terminal supporting ceaseless handover between WCDMA network and a W-LAN(Wireless LAN) network and its method are provided to ensure handover without interruption by installing an MIP(Mobile IP) server controlling an MIP protocol in a service provider local IP backbone. CONSTITUTION: A digital processor(10) includes a main processing unit(20) for controlling a module, a WCDMA processor(30) for performing a communication with WCDMA, and a W-LAN processor(40) for performing a communication with a W-LAN. The main processing unit(20) includes a main processor(21) for performing every function software of a module, a flash memory(22) for booting when power is applied, and a DRAM(23) for driving a software by itself. The main processing unit(20) additionally includes a dual-port RAM(24) connected to a switching buffer(25) for communication with the WCDMA processor(30) and the W-LAN processor(40), and an external matching unit(26) for selecting the CDMA processor(30) and the W-LAN processor(40) and connecting it to an external host. A baseband signal-RF signal interface unit(50) interfaces a baseband signal and an RF signal. An antenna unit(60) radiates an output of a terminal as an electromagnetic wave in space or inputs the electromagnetic wave from space to the terminal.

Description

The terminal and method for supporting seamless handover between broadband code division multiple access network and wireless LAN network {The Structure of Complex Mobile Equipment and its Call Flow to support Seamless Handover between WCDMA and W-LAN Networks}

The present invention is a mobile computer, a mobile phone, a personal digital assistant (PDA), and the like, between a broadband code division multiple access (WCDMA) mobile communication network having an advantage in mobility and a fixed wireless LAN (W-LAN) network capable of high-speed data transmission. The present invention relates to a hybrid terminal and a method for supporting a seamless handover between a wideband code division multiple access network and a wireless LAN network. The RF portion includes a WCDMA unit and a W-LAN unit. A common module of the most common part and MIP server that controls Mobile IP (MIP) protocol in the Service Provider Local IP Backbone, which is a seamless hand between broadband code division multiple access network and wireless LAN network. The present invention relates to a multi- terminal supporting the over and a method thereof.

Recently, unlike the existing communication service using a wired network, wireless communication, a next-generation communication service that enables two-way communication anytime, anywhere without restriction of time and place using a portable terminal or a mobile terminal device (laptop PC, mobile phone, PDA, etc.) It's suddenly rising. In this way, as the wireless communication network has moved to the next generation, a wideband code division multiple access (WCDMA) scheme based on a third generation (3G) network has been developed as a new type of wireless network.

In addition, as communication networks continue to evolve throughout the world, numerous equipment suppliers around the world work with standard groups to manufacture these systems and typically to ensure the commonality and compatibility of the networks.

In addition, a wireless LAN has been developed for converting transmission data between personal computers and servers of each organization into radio signals or optical signals and transmitting and receiving them wirelessly. The wireless LAN is a network connection between a building and a terminal. Various applications are possible in areas where mobility is required or in areas where cable wiring is difficult.

However, in order to access the WCDMA network and the W-LAN network, a dedicated terminal for accessing each network is required. To this end, equipment manufacturers separately develop a WCDMA dedicated terminal and a W-LAN dedicated terminal device. Supply.

Accordingly, users of third generation mobile communication services (3G services) can receive various 3G multimedia services using WCDMA dedicated terminal devices, but have to suffer inconvenience in using high-speed services in real time due to limited wireless capacity. In fact, the wireless capacity of the WCDMA system is difficult to provide more than 384Kbps per subscriber.

In addition, 3G service users can use a W-LAN service area (main school campus, inside a specific building, etc.) because W-LAN supports transmission speed of up to 54Mbps (IEEE 802.11a standard). Must be serviced.

Accordingly, when the 3G service user moves from the WCDMA network to the W-LAN network, the existing WCDMA service is interrupted and there is an inconvenience in that the W-LAN service must be newly accessed.

1 is a diagram illustrating a network configuration of WCDMA based on an IP network which is an evolutionary trend of mobile communication. The difference from the IP network is that the components such as FA / HA / R / BG for IP protocol processing including RNS (Node B + RNC) / SGSN / GGSN / HLR, which are components of the existing WCDMA system, are added. There is. There is also a separate WCDMA terminal. Here, the RNS is a system in which Node B, which is a base station equipment, and RNC, which is a base station controller, are combined, and a Serving GPRS Support Node (SGSN) serves to transmit a packet to an MS in a service area. And, the GGSN (Gate GPRS Supporting Node) is a GPRS network entity that acts as a wireless gateway between SGSN and PDN, and uses the GGSN to handle logical interfaces with external PDNs so that mobile subscribers can access PDNs. HLR (Home Location Register) is located at a fixed point in the network for the mobile terminal and has a database function in the network for managing subscriber level information, location information, etc. for providing services. Represents a register.

In addition, the FA (Foreign Agent) is a router that provides location and connection setting service for the terminal moved to another network, HA (Home Agent) is located in the home network to which the user subscribed to the terminal moved in conjunction with the FA It is a router that maintains the current location information and intercepts the data packet destined for the mobile terminal and delivers it to the moved location. R (Router) is a router and BG (Border Gateway) communicates with routers of other automatic systems. Each of which represents a router.

2 is a diagram illustrating a network configuration of a W-LAN. The W-LAN dedicated terminal (or laptop) is connected to the internet network through an access point, and a hub and a router are located in the middle to route a path that the W-LAN terminal wants to access.

However, in the past, WCDMA terminals having mobility and W-LAN terminals, which are fixed network services, were developed as separate models, respectively, so that a user may be provided with mobility services when the user receives services using the WCDMA terminal. On the other hand, there is a limit to providing high-speed data service due to limited wireless capacity.

In addition, when a user receives a service by using a W-LAN terminal, the user has a merit of providing a high-speed data service, while having a disadvantage of no mobility of the service.

Therefore, when the WCDMA service user enters the W-LAN service area, it is desirable to switch to the W-LAN service, which is a high-speed service. . In order to provide such services seamlessly, there is a need for a hybrid terminal in which WCDMA and W-LAN are implemented in dual mode, but dual mode terminals supporting both WCDMA and W-LAN simultaneously are required. There is a problem that the / W size becomes large.

The present invention has been invented in view of the above-described circumstances, and the RF module can be made as common as possible while mounting the WCDMA processing unit and the W-LAN processing unit in one hardware module in the H / W of the hybrid terminal supporting WCDMA and W-LAN simultaneously. WCDMA and W-LAN share a single RF module so that the appearance of a composite terminal can be miniaturized to provide a hybrid terminal that supports seamless handover between a wideband code division multiple access network and a wireless LAN network. There is an object of the invention.

The present invention also provides a method for seamless handover between a WCDMA mobile communication network having high mobility and a fixed W-LAN network capable of high-speed data transfer by using a composite terminal supporting WCDMA and W-LAN simultaneously. The purpose of the invention is to provide.

1 is a network configuration diagram of WCDMA;

2 is a network configuration diagram of a W-LAN,

3 is a block diagram of a composite terminal according to the present invention;

4 is a configuration diagram of a MIP network between a W-LAN network and a W-CDMA network according to the present invention;

5 is a W-LAN protocol stack,

6 shows a WCDMA protocol stack (user plane),

7 shows a WCDMA protocol stack (control plane),

8 is a call flow diagram when a composite terminal is handed over from a WCDMA service area to a W-LAN service area;

9 shows a call flow diagram in which a composite terminal is handed over from W-LAN to W-CDMA.

* Description of the symbols for the main parts of the drawings *

10-digital processing unit, 20-main processor unit,

30-W-CDMA processor, 40-W-LAN processor,

50-BB-RF Signal Interface Unit, 60-Antenna Unit

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is in charge of the integrated management function of the module, the main processor 21, all the software that performs the function of the module, such as the arbitration function for the port design and release of the WCDMA processing unit 30 and the W-LAN processing unit 40, power is applied Flash memory 22 for self-booting, DRAM 23 for switching on its own software, and a switching buffer 25 are connected to each other so that the dual port RAM for communication between the WCDMA processing unit 30 and the W-LAN processing unit 40 ( A main processor unit (20) comprising a memory block (24) and an external matching unit (26) for selecting a WCDMA processing unit (30) and a W-LAN processing unit (40) to connect with an external host;

W-CDMA modem 31 and its own memory block connected to the switching buffer 25 and the external matching unit 6 of the main processor unit 20, including a CDMA processor and 3GPP all protocol stack function, AMR Codec function A W-CDMA processing section 30 consisting of 32;

A media access controller (MAC) 41 connected to an external matching unit 26 of the main processor unit 20 to communicate with a host through a PCMCIA interface and process user data using a W-LAN protocol; W-LAN processing unit consisting of a baseband processor (BB) 42 and its own memory block 43 for A / D and D / A converter functions for the I / Q data, and the transmitter APC / receiver AGC functions. 40;

I / Q-type baseband transmission signal input from the baseband processor to the uplink to the spreading signal of the IF band and the I / Q to supply the baseband processor the downlink converted signal to the IF band An I / Q demodulation unit 51 which performs a demodulation function to a baseband signal of the type, and up-converts the transmission signal of the IF band to an RF frequency band for wireless connection, and converts the received signal of the RF band to an IF frequency band. The RF interface converter 52 for down-converting the signal, a BB-RF transmitter 53 for converting and transmitting a baseband signal into an RF signal, a BB-RF receiver 54 for converting and receiving an RF signal into a baseband signal, and the BB- A BB-RF signal interface unit 50 connected to the RF transmitters and receivers 53 and 54, respectively, and including SAW filters 55 and 56 for removing influences caused by the proximity band of the signal or an external signal;

Final transmission with a low noise amplifier (LNA) 61 connected to the BB-RF signal interface unit 50 and connected to amplify only a desired signal with respect to noise of an externally input signal and input the same to the RF interface converter 52. It consists of an antenna unit 60 consisting of power amplifiers 62 and 63 and a duplexer 64 which amplify data to a desired output signal power level.

In the seamless handover method between the wideband code division multiple access network and the wireless LAN network according to the present invention, the handset is searched for the size of the WCDMA received energy and the W-LAN received energy when the terminal is moved to the boundary between the WCDMA and the W-LAN. If the WCDMA received energy is reduced and the W-LAN received energy is increased, the handover procedure is performed to the W-LAN network while the W-LAN received energy is reduced and WCDMA is determined. If the received energy is increased, the handover procedure is performed to the WCDMA network.

In addition, the step of performing a handover procedure from WCDMA to W-LAN transmits a "Measurement Report" to the WCDMA network in reverse direction from the MS and the RNC in the WCDMA network compares the received energy reported by the MS to the W-LAN network. Determining the handover to the terminal through the "Handover From UTRAN Command" message to command the handover, the composite terminal acquires the physical initial synchronization for the W-LAN, the "Agent Advertisement" in the MIP server Message is sent to the terminal through the message, and the composite terminal registers with the MIP server through the "MIP Registration Request" message, and then the MIP server registers with the "MIP Registration Reply" message to the terminal. Location registration step using W-LAN network to notify, MIP server transfers data transmission path to W-LAN network And be delivered to the device via the AP, it consists of a service route in the WCDMA network to which the path that was used in the existing WCDMA network is turn off step.

In addition, performing the handover procedure from the W-LAN to the WCDMA includes: arbitrarily disconnecting the wireless section transmission from the W-LAN, acquiring an initial synchronization with the WCDMA, and the WCDMA path from the WCDMA. Registering to the MIP server through the MIP server, the MIP server transfers the transmission path of the user data to the WCDMA network to transfer the data to the terminal through the GGSN and Node B to release the path used in the existing W-LAN network consist of.

3 shows a block diagram of a composite terminal according to the present invention.

The composite terminal according to the present invention includes a single composite module that can be connected to a WCDMA network and a W-LAN network. The composite module is used for communication between the main processor unit 20 that is in charge of the module's main module and WCDMA. Digital processing unit 10 comprising a WCDMA processing unit 30 and a W-LAN processing unit 40 for communication with the W-LAN, and a baseband signal-RF signal interface unit 50 for interfacing the baseband signal with the RF signal. And it is composed of an antenna unit 60 for radiating the output from the terminal as electromagnetic waves into the space or to input the electromagnetic waves from the space into the terminal.

At initial startup, the main processor 21 of the main processor unit 20, the baseband processor 42 of the W-LAN processing unit 40, and the W-CDMA modem 31 of the W-CDMA processing unit 30 each have their own flashes. The boot process is performed by boot code stored in memory.

Thereafter, a process of searching for an RF signal is performed, and a signal input from the antenna unit having a W-LAN function among the antenna units 60 passes through a power amplifier 62 having a T / Rx switching function. Pass through the RF interface converter 52 and then demodulated into a baseband signal in the form of I / Q, and is transmitted to the baseband processor 42.

The baseband processor 42 stores the level and state of the signal currently being received in the dual port RAM 24 in a form capable of informing the main processor 21.

On the other hand, the signal input from the antenna unit of the W-CDMA function of the antenna unit 60 is sent to the BB-RF receiving unit through the duplexer 64, this signal is to be recognized by the WCDMA modem 31 through the SBI bus In addition, the present invention stores the level and state of the current signal in the dual port RAM 24 in a form capable of informing the main processor 21.

In the case of storage in the dual port RAM 24, the switching buffer 25 arbitrates who occupies the bus to store data to avoid collision between the W-LAN baseband processor 42 and the W-CDMA modem 31. The main processor 21 compares the received data signals of the W-LAN and W-CDMA functions and gives priority to the communication with the PCMCIA controller, that is, the external matching unit 26.

In this case, if the priority is occupied by the W-LAN function, when the host wirelessly transmits data through the PCMCIA, the baseband processor 42 transmits the I / Q demodulation unit 51 through the medium access controller 41. After down-modulation to the IF band, the data passes through the RF interface converter 52 and is then transmitted to the antenna through the power amplifier 62 of the antenna unit 60 to be transmitted wirelessly.

However, if the priority is occupied by the WCDMA function, when the host wirelessly transmits data through the PCMCIA, the transmission data is sent to the W-CDMA modem 31 through the external matching unit 26, which is a PCMCIA controller, and then the SBI bus. Through the BB-RF transmitter 53 through the transmitting SAW filter 55 and the power amplifier 63 is sent to the antenna to be transmitted wirelessly.

Also, if the W-LAN function maintains the transmission and reception state with priority, and the user moves and the W-LAN signal state is significantly worsened and the W-CDMA signal state is moved to the transmission / reception area, the main processor 21 determines this. The same applies to the case where the transfer is commanded to the W-CDMA, while the WCDMA function occupies priority and then occurs.

4 is a diagram illustrating a configuration of a MIP network between heterogeneous W-LAN networks and W-CDMA networks.

As described above, the present invention is to enable seamless handover between a WCDMA mobile communication network having an advantage in mobility and a fixed W-LAN network capable of high-speed data transmission, and performs such heterogeneous handover. In order to do this, the application of MIP is essential, and a MIP server controlling the MIP protocol must exist in the service provider's local IP backbone. The MIP server performs an agent (HA or FA) function for each MIP that is currently connected.

Inter Working Function (IWF) performs the matching function between the WCDMA protocol stack and the W-LAN protocol stack. 5, 6, and 7 illustrate the W-LAN protocol stack and the WCDMA protocol stack with reference. In this case, the IWF serves as an end to IP Tunneling (GTP-U) of the WCDMA GGSN and adds a stack required for the W-LAN. In addition, IWF can be operated in two ways to minimize user data loss during hard handover between WCDMA and W-LAN. The first function is to buffer user data during hard handover time. This method may be an ideal method without any user data loss, but there is a limit in buffering all high-speed user data when the number of terminals for hard handover is large. The second method is to ignore user data lost during hard handover. In this case, lost data can be recovered because the upper TCP / IP layer requires retransmission, but this method is disadvantageous for services requiring real time transmission.

8 shows a call flow diagram when the composite terminal is handed over from the WCDMA service area to the W-LAN service area.

The call flow chart is described in order of how the terminal determines handover at the WCDMA and W-LAN boundaries, location registration using the W-LAN network, and service path release in the WCDMA network.

In FIG. 8, S1 to S3 show a process of determining, by the composite terminal, the handover time point to the W-LAN network and stopping transmission of the wireless section by WCDMA.

Step S1 is a process in which the composite terminal determines handover at the WCDMA and W-LAN boundary points, indicating that the terminal has an automatic switching function and a manual switching function by receiving energy search. The first automatic switching function is a method of handover to a system with strong received energy through automatic search of received energy, which is generally applied in a mobile communication system. That is, when a composite terminal currently being serviced in the WCDMA network approaches the W-LAN service area, the terminal determines that the WCDMA energy decreases and the W-LAN receiving energy gradually increases, and performs a hard handover procedure to the W-LAN. Done. The second manual switching function is a method of manually switching by the service user. Since the optimization of the WCDMA network has already been completed, there is a possibility that the WCDMA received energy can be received at a serviceable level even in the W-LAN service area. There is a possibility that the transfer to LAN service is not possible. In this case, it is very likely that W-LAN service will be networked around hot spots. In this case, assuming that the service consumer knows the location of the W-LAN service area, it is advantageous in terms of transmission quality and cost in the W-LAN service area. A method of forcing a service user to perform a switchover to a service through a terminal user interface (UI).

In step S2, the terminal transmits a "Measurement Report" indicating that the composite terminal is handover to the WCDMA network, and the RNC in the WCDMA network compares the WCDMA received energy and the W-LAN received energy reported by the composite terminal to the W-LAN network. The handover is determined and a handover is commanded to the composite terminal through the message "Handover From UTRAN Command". However, since there are no parameters in the 3GPP standard to define handover between WCDMA and W-LAN, the S2 step is not an option available until this parameter is set.

In step S3, the terminal completes the first step of the hard handover by arbitrarily disconnecting the radio section transmission with the WCDMA.

Step S4 is a process in which the terminal acquires initial synchronization with the W-LAN. Initial synchronization with the W-LAN is shown in the form of a box in FIG. 8 since it follows a general W-LAN synchronization process.

Steps S5 through S7 represent a process in which the terminal registers with the MIP server through the W-LAN path. Through this process, the MIP server determines that the terminal is in a handover situation. That is, since an existing registered IP address in WCDMA is registered again through the W-LAN path, the MIP server knows that the handover is being performed from WCDMA to W-LAN. . The message "Agent Advertisement" in step S5 acquires the physical initial synchronization through step S4, and then the MIP server broadcasts the FA information in which the corresponding terminal is located to the terminal. Thereafter, the terminal registers with the MIP server through the "MIP Registration Request" message in step S6, and the MIP server notifies the terminal that registration is completed in the "MIP Registration Reply" message in step S7.

Steps S8 to S11 describe a process in which user data transmitted to the terminal through the WCDMA network is transferred to the terminal through the W-LAN network. In step S8, the MIP server determines that the terminal is in a handover state from the WCDMA network to the W-LAN network because the IP address previously registered through the WCDMA network has been registered with the W-LAN network. Therefore, the MIP server transfers the user data transmission path to the W-LAN network, and the data flow path is transmitted to the terminal through the AP as in step S9. In addition, the path used in the existing WCDMA network must be released, which is performed through steps S10 and S11. That is, in steps S10 and S11, when there is no user data coming from the terminal through the WCDMA path, the SGSN releases the WCDMA path through a "Iu Release Command" message after a specific time.

9 is a flowchart illustrating a call handover of a composite terminal to WCDMA in a W-LAN. The overall call flow is the same as that of FIG. 8, but the hard handover search method of the composite terminal is different from that of FIG. 8. In FIG. 9, there are two methods of the automatic search for the received energy and the manual switching method of the service user. However, only the automatic search for the received energy exists in step S21 of FIG. 9. Since the W-LAN network is serviced within a limited area, the received energy decreases rapidly when it leaves the W-LAN service area. Therefore, it is possible to sufficiently determine when the terminal is switched from W-LAN to WCDMA.

In step S22, the terminal randomly disconnects the radio section transmission with the W-LAN to complete the first step of the hard handover.

In step S23, the terminal acquires initial synchronization with WCDMA. Initial synchronization with WCDMA is shown in box form in FIG. 9 since it conforms to the general WCDMA synchronization process.

Steps S24 to S30 are processes in which the terminal registers with the MIP server through the WCDMA path. Through this process, the MIP server determines that the terminal is in a handover situation. That is, the existing IP address registered in the W-LAN is registered once again through the WCDMA path. . The terminal transmits an "Activate PDP Context Request" message of step S24 to the SGSN and requests a path setting for packet data. Upon receiving the message in step S24, the SGSN selects the nearest GGSN (FA), and sends a "Create PDP Context Request" message in step S25 to the selected GGSN, and the GGSN indicates that a new terminal has entered the network. Recognize. Thereafter, the GGSN sends a "Create PDP Context Response" message of step S26 to SGSN, and SGSN notifies the terminal of completion of the procedure through the "Activate PDP Context Response" message of step S27. It is now a step to register the terminal IP address in the MIP server. The message "Agent Advertisement" in step S28 broadcasts the FA information in which the corresponding terminal is located to the terminal. Thereafter, the terminal registers with the MIP server through the "MIPRegistration Request" message in step S29, and the MIP server notifies the terminal that registration is completed in the "MIP Registration Reply" message in step S30.

Steps S31 to S33 describe a process in which user data transferred to the terminal through the W-LAN network is transferred to the terminal through the WCDMA network. In step S31, the MIP server determines that the terminal is in a handover state from the W-LAN network to the WCDMA network because the IP address previously registered through the W-LAN network has been registered with the WCDMA network. Therefore, the MIP server switches the transmission path of the user data to the WCDMA network, and the data flow path is transmitted to the terminal through the GGSN and the Node B as in step S32. In addition, the path used in the existing W-LAN network must be released, which is performed through step S33. That is, in step S33, if there is no user data coming from the terminal through the W-LAN path, the MIP server automatically releases the W-LAN path after a specific time elapses by a timer.

As described above, the present invention provides a MIP having a composite terminal device that can be connected to a W-CDMA network and a W-LAN network and minimizes a common part, and controls the MIP protocol in a service provider local IP backbone. Having a server has the advantage of seamless handover without affecting existing network software.

Claims (4)

It is responsible for the integrated management function of the module, the main processor 21 that performs all functions of the module, including the arbitration function for port design and release of the WCDMA processing unit 30 and the W-LAN processing unit 40, and the self-booting upon power-on. The flash memory 22 and the DRAM 23 and the switching buffer 25 for driving the software are connected to the dual port RAM 24 for communication between the WCDMA processing unit 30 and the W-LAN processing unit 40. A main processor unit 20 including a memory block and an external matching unit 26 for selecting the WCDMA processing unit 30 and the W-LAN processing unit 40 to connect with an external host; W-CDMA modem 31 and its own memory block connected to the switching buffer 25 and the external matching unit 6 of the main processor unit 20, including a CDMA processor and 3GPP all protocol stack function, AMR Codec function A W-CDMA processing section 30 consisting of 32; A media access controller (MAC) 41 connected to an external matching unit 26 of the main processor unit 20 to communicate with a host through a PCMCIA interface and process user data using a W-LAN protocol; W-LAN processing unit consisting of a baseband processor (BB) 42 and its own memory block 43 for A / D and D / A converter functions for the I / Q data, and the transmitter APC / receiver AGC functions. 40; I / Q-type baseband transmission signal input from the baseband processor to the uplink to the spreading signal of the IF band and the I / Q to supply the baseband processor the downlink converted signal to the IF band An I / Q demodulation unit 51 which performs a demodulation function to a baseband signal of the type, and up-converts the transmission signal of the IF band to an RF frequency band for wireless connection, and converts the received signal of the RF band to an IF frequency band. The RF interface converter 52 for down-converting the signal, a BB-RF transmitter 53 for converting and transmitting a baseband signal into an RF signal, a BB-RF receiver 54 for converting and receiving an RF signal into a baseband signal, and the BB- A BB-RF signal interface unit 50 connected to the RF transmitters and receivers 53 and 54, respectively, and including SAW filters 55 and 56 for removing influences caused by the proximity band of the signal or an external signal; Final transmission with a low noise amplifier (LNA) 61 connected to the BB-RF signal interface unit 50 and connected to amplify only a desired signal with respect to noise of an externally input signal and input the same to the RF interface converter 52. Seamless handover between a wideband code division multiple access network and a wireless LAN network comprising an antenna unit 60 comprising a power amplifier 62, 63 and a duplexer 64, which amplifies data to a desired output signal power level. Multi-function terminal supporting. Determining handover by searching the magnitude of WCDMA received energy and W-LAN received energy when the composite terminal is moved to the boundary between WCDMA and W-LAN, WCDMA received energy Reducing and increasing the W-LAN receiving energy to perform the handover procedure to the W-LAN network, while reducing the W-LAN receiving energy and increasing the WCDMA receiving energy to perform the handover procedure to the WCDMA network. Seamless handover method between wideband code division multiple access network and wireless LAN network. The method of claim 2, wherein performing the handover procedure from the WCDMA to the W-LAN comprises transmitting a "Measurement Report" to the WCDMA network in a reverse direction from the MS and the RNC in the WCDMA network compares the received energy reported by the MS. Determining handover to the W-LAN network and transmitting a handover to the composite terminal through a "Handover From UTRAN Command" message, the composite terminal to obtain the physical initial synchronization for the W-LAN, MIP server Broadcasts FA information on the terminal through the "Agent Advertisement" message to the terminal, and the composite terminal registers with the MIP server through the "MIP Registration Request" message, and then the MIP server registers with the "MIP Registration Reply" message. Location registration step using W-LAN network notifying terminal of completion, MIP server transfers data transmission path of user data to W-LAN network It is possible to seamlessly communicate between the broadband code division multiple access network and the wireless LAN network, including the service path release step in the WCDMA network, which allows the path of the real name to be transmitted to the terminal through the AP and releases the path used in the existing WCDMA network. Handover method. 3. The method of claim 2, wherein the performing of the handover procedure from the W-LAN to the WCDMA includes: arbitrarily disconnecting the radio section transmission from the W-LAN, acquiring an initial synchronization with the WCDMA; When the terminal registers with the MIP server through the WCDMA path, the MIP server transfers the transmission path of the user data to the WCDMA network and transfers the data to the terminal through the GGSN and the Node B, while maintaining the path used in the existing W-LAN network. A seamless handover method between a broadband code division multiple access network and a wireless LAN network comprising the step of releasing.