KR20050053869A - Dual-mode mobile and method for controlling hand-off in the dual-mode mobile - Google Patents

Abstract

The present invention provides a CDMA modem for processing a CDMA signal, a WCDMA modem for processing a WCDMA signal, and control of operation of the CDMA modem and the WCDMA modem, initialization, message exchange, and reporting measurement results on the surrounding wireless environment to a heterogeneous network. A dual mode mobile communication terminal including a dual mode controller that performs a function of converting a message for a message. When the WCDMA modem receives the handoff start message, the dual mode controller initializes the CDMA modem to initialize a peripheral CDMA. The radio environment for the cell is measured, and the dual mode controller transmits the radio environment measurement result for the CDMA cell measured by the CDMA modem to the WCDMA network through the WCDMA modem, and the WCDMA modem transmits the CDMA from the WCDMA network. When the handoff instruction message is received in response to the radio environment measurement result for the cell, the dual mode control is performed. The apparatus controls the CDMA modem so that handoff to the CDMA cell is performed, and when the handoff to the CDMA cell is successful, the dual mode controller deactivates the WCDMA modem. .

Description

Dual-mode mobile communication method and a handoff control method in the mobile communication terminal {Dual-mode mobile and method for controlling hand-off in the dual-mode mobile}

The present invention relates to a mobile communication terminal, and more particularly, to a dual mode mobile communication terminal for selectively switching between one of code division multiplex (CDMA) and asynchronous WCDMA (Wide Band-CDMA). The present invention relates to a handoff control method between heterogeneous networks performed by the mobile communication terminal during handoff.

Mobile communication technology has advanced from unidirectional radio technology, and the analog method of FDMA (Frequency Division Multiple Access), which is represented by the first generation Advanced Mobile Phone System (AMPS), has been developed to provide two-way radio technology, TDMA (Time Division Multiple Access) and CDMA. It has advanced to the 2nd generation digital method represented by (Code Division Multiple Access) and is progressing to the 3rd generation International Mobile Telecommunication (IMT-2000) called the dream mobile communication.

IMT-2000 uses the same wireless access method in a single frequency band to configure the whole world through the same roaming range, and supports high speed with high bandwidth, so that not only existing voice service but also image, moving image, video phone, internet It has been developed to provide wireless multimedia services such as access, and has been standardized by ATDMA and WCDMA. Some countries are commercializing, and Korea is still in preparation for commercialization.

Currently, the 2nd generation mobile communication system using CDMA method is constructed and commercialized nationwide, but the 3rd generation mobile communication system using WCDMA method is still at the level of pilot service. Therefore, the mobile communication network currently established in Korea is in the form of coexistence of a locally established WCDMA network in a widely constructed CDMA network as shown in FIG. 1. In the future when IMT-2000 is commercialized, the WCDMA network will be extended and used together with the CDMA network.

However, in order to commercialize IMT-2000 in Korea, there is a problem that the WCDMA network must absorb all the services of the existing second generation CDMA mobile communication system, and to solve such a problem, handoff between the WCDMA network and the CDMA network is required. Skills that can support this should be followed.

However, there are many difficulties in supporting handoff between a WCDMA network and a CDMA network. This is because the radio access method of the CDMA mobile communication system is synchronous and the radio access method of the WCDMA mobile communication system is asynchronous and has different Radio Access Technology (RAT), and the frequency bands used are different. .

The synchronous wireless access method is a method of synchronizing timing synchronization between the subsystems and the synchronization between the transceiver and the asynchronous method is a method that does not need to synchronize between the subsystem and the transceiver. WCDMA uses 1.9-2.2GHz frequency band and 5MHz bandwidth, while CDMA uses 1.7-1.8GHz frequency band and 1.25MHz bandwidth.

Therefore, for the same reason, a communication service provider has not yet provided a mobile communication terminal based on a handoff technology and a technology for supporting handoff between a WCDMA network and a CDMA network. As a result, the user uses the WCDMA mobile communication terminal M1 to access the WCDMA network and the CDMA mobile communication terminal M2 to access the CDMA network as shown in FIG.

Here, the WCDMA mobile communication terminal M1 and the CDMA mobile communication terminal M2 will be briefly described with reference to FIG. Nearly all WCDMA mobile communication terminals M1 and CDMA mobile communication terminals M2 are WCDMA Radoi Frequency (11) modules for WCDMA, as shown in FIGS. 2A and 2B. ), WCDMA modem 12, and CDMA RF module 21 and CDMA modem 22 in the case of CDMA.

In the above, the RF module is an integrated transmission / reception high frequency circuit unit of a communication device, and all wireless communication devices have a high frequency to transmit a voice signal frequency far and then receive it as an antenna and lower the frequency back to the original frequency (RF). It consists of three parts such as baseband part and logic part which can accurately reproduce negative and high frequency signals. RF module refers to the composing and commercializing the three parts into one module.

The WCDMA RF module 11 is a module that transmits and receives an RF signal conforming to the radio access standard of the WCDMA network, and the WCDMA modem 12 is a WCDMA radio access standard that is received or transmitted through the WCDMA RF module 11. Is a modem that processes the signal. The WCDMA radio access standard is already described internationally and will not be described. The CDMA RF module 21 is a module that transmits and receives an RF signal conforming to the wireless access standard of the CDMA network, and the CDMA modem 22 is a CDMA radio that is received or transmitted through the CDMA RF module 21. It is a modem that processes the signal of connection standard. The CDMA radio access standard is already described internationally and will not be described.

When used in the domestic wireless environment where the WCDMA network and the CDMA network coexist by using the WCDMA mobile communication terminal and the CDMA mobile communication terminal as described above, the user must purchase the mobile communication terminal for each network. There is inconvenience in using, and also bear the problem that the call is disconnected due to no support of handoff during the call.

Accordingly, an object of the present invention is to provide a mobile communication terminal capable of connecting to a WCDMA network and a CDMA network and supporting handoff between the WCDMA network and a CDMA network, respectively.

In order to achieve the above technical problem, the present invention has a frequency band for WCDMA communication and a signal processing device for WCDMA communication, and a frequency band for CDMA communication and a signal processing device for CDMA communication, that is, dual band dual mode. The dual band and the dual mode are controlled to change operations according to a communication area (ie, a WCDMA cell area, a CDMA cell area, and a WCDMA and CDMA boundary cell area), so that handoff can be performed through the control. It is characterized by.

In the above, the frequency band for the WCDMA communication and the frequency band for the CDMA communication are already internationally standardized, and the signal processing method for using each frequency band is also standardized and known. In addition, a signal processing device for WCDMA communication and a signal processing device for CDMA communication are commonly referred to as a WCDMA modem and a CDMA modem.

Accordingly, the present invention according to the first aspect for achieving the above technical problem includes a CDMA modem, a WCDMA modem, a dual-mode controller for controlling the operation of the CDMA modem and the WCDMA modem, the WCDMA modem The wireless mode of the neighboring WCDMA cell is measured and the measurement result is transmitted to the WCDMA network. When the handoff start message and the handoff instruction message to the CDMA network are transmitted from the WCDMA network, the received message is received in the dual mode. The controller transmits the output of the CDMA modem from the dual mode controller to the WCDMA network, and the CDMA modem is handed off from the WCDMA network to the CDMA network according to the control of the dual mode controller. The wireless environment of the neighboring CDMA cell is measured, and the measurement result is transmitted to the dual mode controller, and is received from the dual mode controller. Upon receiving a handoff indication message, the CDMA cell performs handoff. The dual mode controller controls whether the CDMA modem and the WCDMA modem are operated, and receives the handoff start message from the WCDMA modem. It provides a dual-mode mobile communication terminal for initializing the radio environment to measure the wireless environment, and converts the message received from the CDMA modem into a form that the WCDMA modem can receive and transmits it to the WCDMA modem.

In addition, the present invention according to the second aspect for achieving the above technical problem, the CDMA modem for processing the CDMA signal, the WCDMA modem for processing the WCDMA signal, and whether the operation control, initialization, message exchange of the CDMA modem and the WCDMA modem In the handoff method between heterogeneous networks using a dual-mode mobile communication terminal comprising a dual-mode controller for converting a message for reporting a measurement result of the wireless environment to the heterogeneous network, the WCDMA modem Receiving a handoff initiation message, the dual mode controller initializing the CDMA modem to measure a radio environment for a neighboring CDMA cell; and the dual mode controller performing a measurement on the CDMA cell measured by the CDMA modem. A second step of transmitting the radio environment measurement result to the WCDMA network via the WCDMA modem; Receiving a handoff instruction message in response to a radio environment measurement result for the CDMA cell, the dual mode controller controls the CDMA modem to perform a handoff to a CDMA cell; and If the handoff is successful, the dual mode controller provides a handoff control method in a dual mode mobile communication terminal, including a fourth step of deactivating the WCDMA modem.

Hereinafter, a dual mode mobile communication terminal and a handoff method between heterogeneous networks according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, the dual mode mobile communication terminal according to the first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 3, the mobile communication terminal of the present invention includes a WCDMA RF module 11, a WCDMA modem 12, a CDMA RF module 21, a CDMA modem 22, and a dual mode controller 30. An antenna 40 is included. The antenna 40 is preferably a wideband antenna.

As the WCDMA RF module 11, the WCDMA modem 12, the CDMA RF module 21, and the CDMA modem 22 have the same reference numerals as the components in the description with reference to FIG. 2, each module or modem with reference to FIG. However, the WCDMA RF module 11 and the CDMA RF module 21 of the present invention are connected to one broadband antenna 40.

The dual mode controller 30 performs control of operation of the WCDMA modem 12 and the CDMA modem 22, initialization, message exchange, and a message conversion function for reporting a measurement result of the CDMA network to the WCDMA network. As a result, the WCDMA RF module 11, the WCDMA modem 12, the CDMA RF module 21, and the CDMA modem 22 operate under the control of the dual mode controller 30.

Meanwhile, the mobile communication terminal of the present invention may be configured as shown in FIG. 4 is a block diagram of a dual mode mobile communication terminal according to a second embodiment of the present invention.

As shown in FIG. 4, in the mobile communication terminal according to the second embodiment of the present invention, the dual band RF module 10 operates as an RF module for WCDMA according to a compressed mode defined in the WCDMA standard. It acts as an RF module for CDMA. That is, the dual band RF module 10 operates as a WCDMA RF module in the compression mode, and operates as a CDMA RF module in the non-compression mode.

The WCDMA modem 12 and the CDMA modem 22 have been described with reference to FIGS. 2 and 3. The dual mode controller 31 is the same as described with reference to FIG. 3, but sets or releases the compression mode according to the signal received from the base station, and controls the dual band RF module 10 according to whether the compression mode is set. Do it differently.

Hereinafter, the operation of the mobile communication terminal according to the embodiment of the present invention operating at the time of handoff from the WCDMA network to the CDMA network with reference to FIG. I will replace the description of the configuration.

5 is a flowchart illustrating a handoff method using a dual mode mobile communication terminal according to an embodiment of the present invention. The terminal referred to in FIG. 5 is the terminal illustrated in FIG. 3. However, since the operation of the terminal with reference to FIG. 4 can also be easily implemented by those skilled in the art from the description with reference to FIG. When the WCDMA modem 21 or the CDMA modem 22 operates, the RF module 11 or 21 according to the operation of the WCDMA modem 21 or the CDMA modem 22 is omitted, so the description of the WCDMA RF module 11 and the CDMA RF module 21 will be omitted.

The dual mode mobile communication terminal (hereinafter referred to as 'DBDM terminal') of the present invention monitors (ie, measures) signals received from neighboring wireless cells at predetermined cycle times, and monitors WCDMA monitoring results of the surrounding wireless cell environment. It informs the WCDMA Radio Network Controller (RNC) 50 through the Radio Network Subsystem (RNS). In this case, the message for transmitting the radio environment monitoring result transmitted from the DBDM terminal is 'RRC (Radio Resource Control) / Measurement Report', and the RRC / Measurement Report message is defined in the WCDMA standard.

In this state, when the DBDM terminal is located in the WCDMA network and attempts to make a call, the dual mode controller 30 activates the WCDMA modem 12 to transfer an incoming call to the WCDMA control station 50 through the RF module 11 for WCDMA. send. As a result, the DBDM mobile communication terminal makes a call in the WCDMA network, where the WCDMA modem 12 is in a connected mode.

When the user moves and arrives at the point A of FIG. 1 while talking on the WCDMA network, the DBDM terminal periodically monitors the environment of the neighboring WCDMA cell, that is, the strength of the signal received from the neighboring WCDMA cell. 50) (S1).

When the WCDMA control station 50 receives the environment information of the neighboring WCDMA cell from the DBDM terminal, the WCDMA control station 50 determines whether the DBDM terminal is handed off. As an example, if the environment of the WCDMA cell cannot continue a call (that is, the strength of the signal transmitted from the WCDMA cell is less than the reference value), the WCDMA control station 50 determines that the situation is to be handed off.

If it is determined by the determination that the WCDMA control station 50 is in a situation of handoff (S2), to determine whether handoff to a CDMA cell located near the DBDM terminal is possible, the WCDMA control station 50 moves to the CDMA cell together with the CDMA cell information located around the DBDM terminal. A message indicating the start of handoff is transmitted to the WCDMA modem 12 (S3).

Here, the meaning of the handoff initiation is defined. The handoff initiation is not a command to perform a handoff, but an initial operation required for handoff. The initial operation for handoff is to find a partner to hand off and to grasp handoff parameter information for the partner to be handed off. The command to perform the handoff used in the present invention is referred to as a handoff indication. Accordingly, handoff initiation will be understood to be distinguished from handoff instructions described below.

When the WCDMA modem 12 receives the handoff start message from the WCDMA control station 50 to the CDMA cell, the WCDMA modem 12 transmits the received message to the dual mode controller 30 (S4).

Then, the dual mode controller 30 activates the CDMA modem 22 which is inactivated to monitor the CDMA cell, and the CDMA modem 22 of the CDMA cell to monitor the radio environment included in the received message. The information is transmitted (S5).

At this time, the CDMA modem 22 is activated and initialized by the dual mode controller 30 and enters the standby mode. The initialization of the CDMA modem 22 is a state in which the radio environment of the CDMA cell can be measured according to a parameter set in the modem 22, or a handoff start message received from the WCDMA control station 50. The parameter included in the state of measuring the radio environment of the CDMA cell.

Here, when the DBDM terminal is initialized by the set parameter, as described in the conventional CDMA module, the DBDM terminal measures a pilot signal or a beacon signal to measure the radio environment of the neighboring CDMA cells, and by the dual mode controller 30. When initialized by the provided initial parameters, the initial parameters are obtained from neighboring CDMA cells to measure the radio environment of the CDMA cells.

The initial parameters are parameters provided by the dual mode controller, such as frequency, number of terminals (IMSI), and pilot offset values of neighboring cells. When the initialization process starts with these values, a paging slot is acquired through a CDMA system acquisition process. Access parameters, IDs of CDMA cells, and the like.

The initialized CDMA module 22 measures the radio environment of neighboring CDMA cells and transmits the measurement result to the dual mode controller 30 (S6). Accordingly, the dual mode controller 30 converts the measurement result sent by the CDMA module 22 into a data form that the WCDMA module 12 can receive in order to transmit the received measurement result to the WCDMA control station 50. (S7), Transfer to WCDMA module 12 (S8). When the WCDMA module 12 receives the measurement result, it transmits it to the WCDMA control station 50 (S9).

Upon receiving the radio environment measurement result of the CDMA cell, the WCDMA control station 50 determines the CDMA cell (i.e., base station) to be handed off by the DBDM terminal from the received measurement result (S10), and performs handoff to the determined CDMA base station. A handoff parameter (ie, PN offset, Walsh code, long code state used in a traffic channel, timing information, pilot offset, etc.) necessary for the transmission is transmitted to the WCDMA modem 12 in a handoff indication message (S11).

When the WCDMA modem 12 receives the handoff instruction message, the WCDMA modem 12 extracts the handoff parameter included in the handoff instruction message and includes the extracted handoff parameter in an internal message indicating the handoff to the dual mode controller 30. It transmits (S12). Then, the dual mode controller 30 includes the received handoff parameter in a message conforming to the CDMA standard and transmits it to the CDMA modem 22 (S13).

When the CDMA modem 22 receives the handoff parameter, the CDMA modem 22 performs handoff to the base station of the corresponding CDMA cell according to the received parameter. If the handoff succeeds, the CDMA modem 22 controls the dual mode controller 30 and the CDMA. It transmits to the station 60 (S14).

If the handoff is successful, the dual mode controller 30 switches the CDMA modem 22 to the connected mode, releases the WCDMA radio resources allocated to the WCDMA modem 12, and then deactivates the WCDMA modem 12 (S16). .

As a result, the DBDM terminal handoffs to the CDMA cell to provide a continuous call service to the user without interruption of the call.

In the above, deactivating the CDMA modem 22 when the WCDMA modem 12 is in the connected mode, or deactivating the WCDMA modem 12 when the CDMA modem 22 is in the connected mode is an action to prevent waste of power. .

Hereinafter, an example of a message used in each process of the embodiment of the present invention with reference to FIG. 5 will be described.

In step S1, the WCDMA module 12 transmits an RRC / Measurement Report message to the WCDMA control station 50. As described above, the RRC / Measurement Report message is a message defined in the WCDMA standard, an external message (ie, an external transmission message), and informs the result of the measurement of the radio environment of the WCDMA cell.

In step S3, the WCDMA control station 50 transmits an RRC / Measurement Control message to the WCDMA module 12. The RRC / Measurement Control message is a message instructing to measure the radio environment of the CDMA cell for handoff to the CDMA cell, and is used between heterogeneous RATs (inter_RAT). The data format of this message is WCDMA, but the content is CDMA. This message is defined in the WCDMA specification and is an external message.

In step S4, the WCDMA modem 12 transmits a cdma_measure_control message to the dual mode controller 50. This message is an internal message (message for terminal internal use) as a message for instructing the CDMA modem 22 to start handoff (i.e., to measure the surrounding radio cell environment to determine the target and target information to be handed off). The following internal messages are described in detail below.

In step S5, the dual mode controller 30 transmits a module active message to the CDMA module 22. The message contains an initialization instruction and CDMA environment measurement condition information and is an internal message.

In step S6, the CDMA modem 22 transmits a pilot measurement report message (PMRM) message containing the radio environment measurement result to the dual mode controller 30. More specifically, the present invention uses a Pilot Strength Measurement Message (PSMM) message as a PMRM message. The PSMM message includes PN offset and pilot signal strength information as a radio environment measurement result. This message is an internal message translated from the message defined in the CDMA specification.

In step S8, the dual mode controller 30 transmits a cdma_measure_report message to the WCDMA modem 12. This message contains the contents of the PSMM message, and the PSMM message has been changed for WCDMA. This message is an internal message translated from the message defined in the CDMA specification.

In step S9, the WCDMA modem 12 transmits an RRC / UE Capability information message containing the PSMM message to the WCDMA control station 50. This message is used between heterogeneous RATs, and the content contained in this message is used for handoff through interworking between a WCDMA network and a CDMA network. This message is an external message. Meanwhile, in the current WCDMA standard, there is an RRC / Measurement Control message requesting the start of radio environment measurement for a CDMA network from a WCDMA control station, but a message for reporting the measurement result of the CDMA network to the WCDMA control station as an RRC / Measurement Report message. And procedures are not defined. Therefore, the present invention is not a new type of message reporting the measurement of the radio environment from the CDMA network to the WCDMA network, but among the RRC messages defined in the WCDMA standard, the UE can send the CDMA message without paying the instruction of the control station. ) RRC / UE Capability information message that can be transmitted is used. Since the UE may transmit up to four CDMA network messages at once using the RRC / UE Capability information message, the present invention uses the RRC / UE Capability information message for the PMRM message (ie, the PSMM message) by the CDMA modem. To the WCDMA control station 50.

In step S11, the WCDMA control station 50 transmits an RRC / Handover From UTRAN Cmd message to the WCDMA modem 12. This message indicates a handoff to the CDMA network, and details include handoff parameters (PN offset, longcode status, pilot offset, Walsh code, etc.) that must be transmitted from the CDMA network to the CDMA modem. This message is defined in the WCDMA specification.

In step S12, the WCDMA modem 12 transmits the cdma2000MessagePayload-Handoff Direction Message to the dual mode controller 30. This message includes the handoff parameter included in the RRC / Handover From UTRAN Cmd message. This message is an internal message translated from the message defined in the CDMA specification.

In step S13, the dual mode controller 30 transmits a handoff direction message to the CDMA modem 22. This message indicates a handoff to the CDMA service area and is an internal message converted from a message defined in the CDMA standard.

In step S14, the CDMA modem 22 transmits a handoff complete message to the dual mode controller 30. This message indicates a successful handoff. It is an internal message converted from a message defined in the CDMA standard.

In step S14, the CDMA modem 22 transmits a CDMA / Handoff Complete message to the WCDMA control station 50. This message indicates a handoff success and is an external message.

In step S15, the dual mode controller 30 transmits a wcdma_rrc_release message to the WCDMA modem 12. This message is for releasing WCDMA radio resources allocated to the WCDMA modem and is an internal message.

In step S15, the dual mode controller 30 transmits a module deactive message to the WCDMA modem 12. This message disables the WCDMA modem and is an internal message.

The basic data format of the above-described internal message is as shown in FIG. 6. 6 is a basic data format of an internal message according to an embodiment of the present invention. As shown in FIG. 6, the internal message includes Dst (f1), Src (f2), Msg_Tag (f3), Bit_Len (f4), and payload f5.

Dst (f1) indicates a destination, that is, a receiver of the message, and Src (f2) indicates a source, namely, the sender of the message. Msg_Tag (f3) is an instruction indicating a message type of data contained in the payload f5, and Bit_Len indicates the number of bits of the payload f5 and according to the maximum length of the payload f5 in the implementation. Allocate the Bit_Len field sufficiently. The payload f5 is an area in which actual data is transmitted when a message is exchanged between modules. Messages except internal messages are interpreted as messages defined in the CDMA standard and the WCDMA standard in each module according to Dst (f1).

The Msg_Tag is shown in the following table.

 Msg_Tag Value  Course                meaning CDMA_MEAS_CTRL   0    S4  CDMA Measurement Control CDMA_MODULE_ACT   One    S5  CDMA Moule Activate CDMA_PMRM   2    S6  CDMA Pilot Measurement Report Message CDMA_MEAS_PRT   3    S8  CDMA Measurement Report CDMA_MSG_PAYLOAD   4    S12  CDMA Message Payload CDMA_HDM   5    S13  CDMA Handoff Direction Message CDMA_HCM   6    S14  CDMA Handoff Complete Message WCDMA_RL_REL   7    S15  WCDMA Radio Link Release WCDMA_MODULE_DEACT   8    S15  WCDMA Module Deactivate

The payload according to Msg_Tag is as follows.

The payload of CDMA_MEAS_CTRL basically includes Measure Type, CellList, and CellID. Measure Type indicates the purpose for which the message is to be used, CellList is a list of CDMA cells to measure the radio environment, and CellID is the ID of the CDMA cell to measure the radio environment. The payload of CDMA_MODULE_ACT is the initial information used in the CDMA module (ie, NAM (number assignment module, basic phone number, etc.), and records the phone number assigned at the time of subscription. Module) that stores the settings for the network), configuration, radio environment measurement parameters, etc.) and the payload of CDMA_MEAN_CTRL. The payload of CDMA_PMRM consists of PN offset and pilot strength. The payload of CDMA_MEAS_RPT consists of the payload of CDMA_PMRM sent to the dual mode controller. The payload of CDMA_MSG_PAYLOAD consists of CDMA2000 messages for handoff received on the WCDMA network via RRC / Handover From UTRAN Cmd.

The payload of CDMA_HDM consists of a handoff parameter for performing handoff in a CDMA network. The payload of CDMA_HCM consists of parameters for status reporting after handoff in CDMA network. The payload of WCDMA_RL_REL is basically composed of parameters for releasing the radio connection to the WCDMA network after successful handoff execution. The payload of WCDMA_MODULE_DEACT is not required by default, and additionally, a field may be added when an additional configuration is required for quick start when reactivation is resumed after deactivation according to the WCDMA module. Except for the payload of the CDMA_HDM, the payload of the remaining Msg_Tag may be added with a user's arbitrary field in actual implementation.

Meanwhile, in the embodiment of the present invention, the DBDM terminal has described the handoff method at the point A of FIG. 1, that is, the handoff method from the WCDMA network to the CDMA network, but those skilled in the art will appreciate the method of handoff from the CDMA network to the WCDMA network or the like. It will be easily implemented through the above description.

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

The present invention provides a DBDM mobile communication terminal that supports handoff between a WCDMA network and a CDMA network, so that a user can make a call without interruption even when the user enters a heterogeneous network through the boundary region of the WCDMA network and the CDMA network. have.

1 is a diagram briefly illustrating a relationship between a general WCDMA network and a CDMA network.

2 is a block diagram showing the configuration of a typical WCDMA mobile communication terminal and a CDMA mobile communication terminal.

3 is a block diagram of a dual mode mobile communication terminal according to a first embodiment of the present invention.

4 is a block diagram of a dual mode mobile communication terminal according to a second embodiment of the present invention.

5 is a flowchart illustrating a handoff method using a dual mode mobile communication terminal according to an embodiment of the present invention.

Claims (9)

It includes a CDMA modem, WCDMA modem, dual mode controller for controlling the operation of the CDMA modem and the WCDMA modem, The WCDMA modem measures the radio environment of neighboring WCDMA cells and transmits the measurement result to the WCDMA network, and receives a handoff start message to the CDMA network and a handoff indication message to the CDMA network. Transmits to the dual-mode controller, receives the output of the CDMA modem to be transmitted to the WCDMA network from the dual-mode controller and transmits to the WCDMA network, When the CDMA modem is handoff from the WCDMA network to the CDMA network, the CDMA modem measures the radio environment of neighboring CDMA cells under the control of the dual mode controller and transmits the measurement result to the dual mode controller, and is received from the dual mode controller. Upon receiving the handoff indication message, handoff is performed to a CDMA cell, When receiving the handoff start message from the WCDMA modem, the dual mode controller initializes the CDMA modem to measure a wireless environment, and converts the message received from the CDMA modem into a form that the WCDMA modem can receive. Dual-mode mobile communication terminal, characterized in that for transmitting to the WCDMA modem. The method according to claim 1, And the RF module required for receiving and transmitting the signal processed by the WCDMA modem and the CDMA modem is configured independently of the WCDMA RF module and the CDMA RF module. The method according to claim 1, The WCDMA modem and the RF module required for receiving and transmitting the signal processed by the CDMA modem are composed of one dual mode RF module, and the dual mode RF module is a compressed mode defined in the WCDMA standard. Mode) operating in the compression mode in the WCDMA RF module, and the dual mode mobile communication terminal, characterized in that the operation in the CDMA RF module in the non-compression mode. The method according to claim 2 or 3, And the dual mode controller activates the WCDMA modem and the CDMA modem simultaneously only in a handoff boundary region, and activates only one modem in the other region. The method according to claim 3, The WCDMA modem When the radio environment measurement result message for the CDMA cell measured by the CDMA modem is received from the dual mode controller, the dual mode mobile communication is transmitted to the WCDM network using the RRC / UE Capability Information message defined in the WCDMA standard. terminal. CDMA modem processing the CDMA signal, WCDMA modem processing the WCDMA signal, and the message for controlling the operation of the CDMA modem and the WCDMA modem, initialization, message exchange, and reporting the measurement results of the surrounding wireless environment to the heterogeneous network. In the handoff method between heterogeneous networks using a dual mode mobile communication terminal comprising a dual mode controller for performing a function for converting, The dual mode controller, when receiving a handoff start message transmitted from a WCDMA network from the WCDMA modem, activates the CDMA modem to measure a radio environment for a neighboring CDMA cell; The dual mode controller converts the radio environment measurement result for the CDMA cell measured by the CDMA modem into a message that the WCDMA modem can receive and transmits the message to the WCDMA modem; When the dual mode controller receives the handoff indication message transmitted from the WCDMA network from the WCDMA modem, the dual mode controller converts the received message into a message that can be received by the CDMA modem and transmits the message to the CDMA modem. A third step of performing a handoff to this CDMA cell; And And a fourth step of deactivating the WCDMA modem after releasing the radio resource allocated to the WCDMA modem if the handoff to the CDMA cell is successful. The method according to claim 6, In the second step, the radio environment measurement result for the CDMA cell measured in the second step is transmitted in the form of an RRC / UE Capability Information message that the UE can transmit without an instruction of the control station among the RRC messages defined in the WCDMA standard. A handoff control method in a dual mode mobile communication terminal, characterized in that. The method according to claim 6, In the fourth step, the handoff indication message received by the WCDMA modem from the WCDMA network includes handoff parameter information for enabling handoff to a CDMA cell, and the dual mode controller transmits the handoff parameter information to the CDMA. A handoff control method in a dual mode mobile communication terminal, characterized by informing the modem. CDMA modem processing the CDMA signal, WCDMA modem processing the WCDMA signal, and the message for controlling the operation of the CDMA modem and the WCDMA modem, initialization, message exchange, and reporting the measurement results of the surrounding wireless environment to the heterogeneous network. In the processor of the dual mode mobile communication terminal comprising a dual mode controller for performing a function for converting, Receiving a handoff start message transmitted from a WCDMA network from the WCDMA modem by a dual mode controller, activating the CDMA modem to measure a radio environment for a neighboring CDMA cell; A second step of the dual mode controller converting a radio environment measurement result for the CDMA cell measured by the CDMA modem into a message that the WCDMA modem can receive and transmitting the message to the WCDMA modem; When the dual mode controller receives the handoff indication message transmitted from the WCDMA network from the WCDMA modem, converts the received message into a message that the CDMA modem can receive and transfers the message to the CDMA modem. A third step of performing a handoff to this CDMA cell; And If the handoff to the CDMA cell is successful, the computer-readable recording medium having recorded thereon a program capable of executing the fourth step of deactivating the WCDMA modem after the dual mode controller releases the radio resource allocated to the WCDMA modem. .