KR100655571B1 - Dual mode mobile communication terminal and method for controlling handover in the dual mode mobile communication terminal - Google Patents

Abstract

A dual-mode mobile communication terminal and a handover control method in the dual-mode mobile communication terminal are provided to obtain and store synchronous information of a synchronous network in idle time, and to detect synchronous information of the synchronous network to compare the detected information with the synchronous information obtained for an idle time, when the terminal enters the synchronous network, in order to use the comparison result for transition to the synchronous network. A terminal detects synchronous information of a synchronous system by using instant time in asynchronous idle mode(S50-S58), and calculates a synchronous frame time difference between synchronous and asynchronous systems by using the detected synchronous information(S60). The terminal stores the synchronous information and the frame time difference in a memory(S62). If a call setup request is generated in the asynchronous idle mode, the terminal establishes a call with the asynchronous system, and performs call processing with the asynchronous system(S64-S80). If a handover event to the synchronous system occurs, the terminal sets a CM(Compressed Mode), and receives synchronous information from the synchronous system(S82-S86). The terminal compares the received synchronous information with the synchronous information stored in the memory(S88). If a handover message indicative of transition to the synchronous system from the asynchronous system is received, the terminal establishes a call with the synchronous system, and performs a call cancellation procedure with the asynchronous system while performing call processing with the synchronous system(S90-S98).

Description

DUAL MODE MOBILE COMMUNICATION TERMINAL AND METHOD FOR CONTROLLING HANDOVER IN THE DUAL MODE MOBILE COMMUNICATION TERMINAL}

1 is a view schematically showing a configuration of a conventional dual mode mobile communication terminal.

2 is a flowchart for explaining a handover control method in a conventional dual mode mobile communication terminal.

3 shows a frame structure of a synchronization system.

4 illustrates a frame structure of an asynchronous system.

5 is a diagram illustrating a case where a CM mode occurs over two frames.

6 is a schematic view showing the configuration of a dual mode mobile communication terminal according to one embodiment of the present invention;

7 is a flowchart illustrating a handover control method in a dual mode mobile communication terminal according to an embodiment of the present invention.

FIG. 8 illustrates an absolute time between any base station cell in an asynchronous network and a synchronous system. FIG.

FIG. 9 is a diagram illustrating an absolute time converted by a dual mode mobile communication terminal as it moves from one base station cell (n) of the asynchronous network to another base station cell (y).

*** Explanation of symbols for the main parts of the drawing ***

30. RF switch, 31. RF module for CDMA, 32. CDMA modem,

33. RF module for WCDMA, 34. WCDMA modem, 35, 36. DPRAM,

37.Common module, 38.Application processor, 39.Memory

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handover control method in a dual mode mobile communication terminal and a dual mode mobile communication terminal. In particular, a dual mode mobile enables to control a handover function in a mobile communication network in which an asynchronous network and a synchronization network are mixed. A handover control method in a communication terminal and a dual mode mobile communication terminal.

Generally, 3G mobile communication systems are classified into a code division multiple access (CDMA) based synchronous system and a wideband CDMA (WCDMA) based asynchronous system, and provide services in a mixed state of asynchronous and synchronous networks. .

Accordingly, when a terminal user moves between an asynchronous mobile communication system and a synchronous mobile communication system, a handover between systems is required for interworking with a network for continuous service provision.

1 is a diagram schematically illustrating a configuration of a conventional dual mode mobile communication terminal, a diplexer 10, a CDMA RF module 11, a CDMA modem 12, a WCDMA RF module 13, and WCDMA. The modem 14 and the common module 17 are provided.

In such a configuration, the diplexer 10 separates two signals having different frequencies (CDMA & WCDMA) by a combination of a low pass filter (LPF) and a high pass filter (HPF). The CDMA frequency signal is applied to the CDMA RF module 11, and the WCDMA frequency signal of the 1.9 to 2.2 GHz band is applied to the WCDMA RF module 13.

The RF module 11 for CDMA transmits and receives an RF signal conforming to the radio access standard of the CDMA network.

The CDMA modem 12 processes signals of the CDMA radio access standard received or transmitted via the RF module 11 for CDMA.

The WCDMA RF module 13 transmits and receives an RF signal that conforms to the wireless access standard of the WCDMA network.

The WCDMA modem 14 processes signals of the WCDMA radio access standard that are received or transmitted through the RF module 13 for WCDMA.

The common module 17 is connected to the Dual Port RAM (DPRAM) 15, 16 which is connected to the CDMA modem 12 and the WCDMA modem 14, and the overall synchronous and asynchronous communication of the dual mode mobile communication terminal. An application processor 18 for performing control and application execution, a memory 19 for storing data, and the like.

2 is a flowchart illustrating a handover control method in a conventional dual mode mobile communication terminal.

First, when power is supplied to the dual mode mobile communication terminal (S10), the dual mode mobile communication terminal performs initialization (S12), detects the synchronization information of the asynchronous system and synchronizes with the asynchronous system (S14), and then asynchronously. Enter the standby mode (S16).

Subsequently, when a call setup request is generated in the asynchronous standby mode (S18), the dual mode mobile communication terminal performs call setup with the asynchronous system (S20), and then receives the WCDMA data received through the antenna and the diplexer 10. The WCDMA RF module 13 and the WCDMA modem 14 are transferred to the application processor 18 to perform call processing (S22).

While performing the call processing with the asynchronous system through the above-described process S22, the dual mode mobile communication terminal continuously measures the sensitivity of the signal received from the asynchronous system, but the signal sensitivity is lowered below the specified threshold, thereby handover to the synchronous system. When the specific condition for the operation is satisfied (S24), the dual mode mobile communication terminal requests a handover to the asynchronous system and simultaneously activates the RF module 11 and the CDMA modem 12 for the CDMA (S26). The sync information of the synchronous system is detected through the CDMA RF module 11 and the CDMA modem 12 while maintaining the asynchronous system and the call continuously through the flexor 10 (S28).

In step S26, the asynchronous system that receives the handover request from the dual mode mobile communication terminal requests the handover of the dual mode mobile communication terminal to the synchronous system, and the handover requested synchronous system sets up the call according to the handover request. After allocating the necessary resources, preparing the path, and transmitting the response signal for the handover request to the asynchronous system, the asynchronous system receiving the response signal for the handover request from the synchronous system is a dual mode mobile communication terminal. A handover message is sent to the local synchronization system. The handover message includes routing information (e.g., information corresponding to frequency, pilot, PN offset, etc. for the target cell) required for call setup with the synchronization system. Included.

On the other hand, when the dual mode mobile communication terminal which has detected the synchronization information of the synchronization system through the above-described process S28 receives a handover message to transition from the asynchronous system to the synchronous system while continuously maintaining a call with the asynchronous system (S30). The call connection with the synchronization system is completed using the synchronization information of the synchronization system detected through the process S28 and the path setting information included in the handover message (S32), and the data received through the asynchronous system is received. It is provided through the synchronization system (S34).

At the same time, the dual mode mobile communication terminal performs a call release procedure with the asynchronous system.

Thereafter, when a call release request occurs (S36), the dual mode mobile communication terminal terminates the call with the synchronization system and then transitions to the synchronization standby mode (S38).

As described above, the conventional dual mode mobile communication terminal acquires synchronization information of an asynchronous network and a synchronous network using a hardware chip such as a diplexer. Therefore, in the related art, since the diplexer is necessarily used, the terminal price increases, the hardware configuration is complicated, and both the asynchronous mode and the synchronous mode are operated, thereby increasing the power consumption of the terminal. In addition, as the hardware configuration becomes more complicated, the area of the terminal is limited for noise removal, and thus there is a problem in that call quality is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem. When the terminal enters a synchronous network after acquiring and storing time information of a synchronous mode at idle time, the time of the synchronous system is controlled through a compressed mode (CM) mode. To provide a handover control method in a dual mode mobile communication terminal and a dual mode mobile communication terminal that detects the information and compares it with the time information obtained during the idle time, and can be used when transitioning to the synchronization system. There is this.

A dual mode mobile communication terminal according to an embodiment of the present invention for achieving the above object, the control unit for controlling the operation of the CDMA RF module, CDMA modem, WCDMA RF module, WCDMA modem operation; And an RF switch for applying an RF signal received through an antenna to one of the CDMA RF module and the WCDMA RF module under the control of the controller, wherein the controller is configured for the WCDMA for a limited time in an asynchronous standby mode. Preferably, the RF module and the WCDMA modem are deactivated and the CDMA RF module and the CDMA modem are activated to detect synchronization information of the synchronization system.

On the other hand, the handover control method in a dual mode mobile communication terminal according to an embodiment of the present invention, the dual mode mobile communication terminal in the asynchronous standby mode using a time limit for detecting the synchronization information of the synchronization system; Calculating a synchronous frame time difference between the synchronous system and the asynchronous system using the synchronous information of the synchronous system; Storing the synchronization information of the synchronization system and the synchronization frame time difference in a memory; When a call establishment request is generated in the asynchronous standby mode, establishing a call with the asynchronous system and performing call processing with the asynchronous system; During the call processing with the asynchronous system, if a handover event to the synchronous system occurs, setting the CM mode based on the synchronous frame time difference, and then receiving the synchronization information from the synchronous system in the CM mode operation period. and; Checking the synchronization information of the synchronization system by comparing the synchronization information received from the synchronization system with the synchronization information stored in the memory; When receiving a handover message to transition to the synchronous system from the asynchronous system, after setting the call with the synchronous system using the synchronization information of the identified synchronous system and the routing information included in the handover message, the synchronous system And performing a call release procedure with the asynchronous system simultaneously with performing call processing.

Further, detecting the synchronization information of the synchronization system is to deactivate the WCDMA RF module and the WCDMA modem for a short time in the asynchronous standby mode, and to activate the CDMA RF module and the CDMA modem and then detect the synchronization information of the synchronization system. desirable.

If the call does not occur continuously, it is preferable to detect and update the synchronization information of the synchronization system at regular intervals.

When the dual mode mobile communication terminal moves from cell to cell within an asynchronous system area, detecting synchronization information of the moved cell; Calculating a synchronous frame time difference generated between the moved asynchronous cell and the synchronous system using the synchronous information of the synchronous system and the synchronous information of the moved cell; The method may further include storing the calculated absolute time in the memory.

Hereinafter, a handover control method in a dual mode mobile communication terminal and a dual mode mobile communication terminal according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Prior to describing a handover control method in a dual mode mobile communication terminal according to the present invention, a frame structure of a synchronous system and an asynchronous system will be described.

First, in a synchronous system, the synchronization information (Super Frame) is the same in a radio section, and in an asynchronous system, the difference occurs between base station cells.

As described above, the frame structure of the synchronous system includes frames in units of 80 msec, while the frame structure of the asynchronous system includes frames in units of 10 msec as shown in FIG.

On the other hand, in the present invention, when it is necessary to transition to the synchronous system while performing the call processing with the asynchronous system, the CM mode is used to detect the synchronization information of the synchronous system, and the CM mode transmits temporarily (several msec) during the call processing. A function for stopping a reception operation. The slot size to which data is transmitted can be changed within one frame, and the empty slot size is determined according to the result.

As described above, during the time when the transmission / reception operation is temporarily stopped, the dual mode mobile communication terminal temporarily changes the reception frequency to a frequency capable of receiving data transmitted by the synchronization system to detect synchronization information of the synchronization system. .

The time at which the transmission / reception operation is temporarily stopped may be set over one or two frames, and may have up to seven slots per frame, and up to 14 slots for two consecutive frames. 5 illustrates a case where a CM mode occurs over two frames.

6 is a road, RF switch 30, CDMA RF module 31, CDMA modem 32, WCDMA RF module 33 schematically showing the configuration of a dual-mode mobile communication terminal according to an embodiment of the present invention ), A WCDMA modem 34, and a common module 37.

In such a configuration, the RF switch 30 applies an RF signal received through an antenna to either the CDMA RF module 31 or the WCDMA RF module 33 under the control of the application processor 38.

The RF module 31 for CDMA transmits and receives an RF signal conforming to the radio access standard of the CDMA network.

The CDMA modem 32 processes signals of the CDMA radio access standard received or transmitted via the RF module 31 for CDMA.

The WCDMA RF module 33 transmits and receives an RF signal that conforms to the wireless access standard of the WCDMA network.

The WCDMA modem 34 processes signals of the WCDMA radio access standard received or transmitted via the RF module 33 for WCDMA.

The common module 37 is connected to the Dual Port RAM (DPRAM) 35, 36, which is connected to the CDMA modem 32 and the WCDMA modem 34, and is used for the overall synchronous and asynchronous communication of the dual mode mobile communication terminal. An application processor 38 for performing control and application execution, a memory 39 for data storage, and the like.

7 is a flowchart illustrating a handover control method in a dual mode mobile communication terminal according to an embodiment of the present invention.

First, when power is supplied to the dual mode mobile communication terminal (S50), the dual mode mobile communication terminal performs initialization (S52), detects the synchronization information of the asynchronous system and synchronizes with the asynchronous system (S54) at any time. The system enters the asynchronous standby mode that can set and process the call with the asynchronous system (S56).

Thereafter, the dual mode mobile communication terminal detects the synchronization information of the synchronization system by using a temporary time without performing call processing (S58). By using the detected synchronization information of the synchronization system, a synchronization frame time difference (hereinafter, referred to as "absolute time") generated between the synchronization system and the asynchronous system is calculated (S60), and the synchronization system detected in step S58 described above. The synchronization information and the absolute time calculated in the above-described process S60 are stored in the memory 39 (S62).

8 is a diagram illustrating an absolute time between any base station cell of an asynchronous network and a synchronous system.

In order to detect the synchronization information of the synchronization system through step S58, the dual mode mobile communication terminal deactivates the WCDMA RF module 33 and the WCDMA modem 34 for a limited time, and the CDMA RF module 31 and CDMA After activating, the modem 32 detects the synchronization information of the synchronization system. If no call is generated, the modem 32 detects and updates the synchronization information of the synchronization system at regular intervals.

And, the absolute time calculated through the process S60 described above is required to perform handover to the synchronous system as the dual mode mobile communication terminal moves out of the jurisdiction of the asynchronous system to the synchronous system during call processing. It is used to detect accurate synchronization information of the synchronization system.

After detecting the synchronization information of the synchronization system through step S58, the dual mode mobile communication terminal transitions the operation mode back to the asynchronous standby mode (S64).

On the other hand, the dual-mode mobile communication terminal is to move between cells in the area of the asynchronous system, in the asynchronous network, the synchronization information is changed in accordance with the cell movement.

Accordingly, when the dual mode mobile communication terminal moves from any base station cell in the asynchronous network to another base station cell, it detects synchronization information of the moved cell (S66, S68), and synchronizes the synchronization information of the synchronization system detected in step S58. Using the synchronization information of the asynchronous system detected in step S68, an absolute time generated between the moved asynchronous cell and the synchronous system is calculated (S70), and the calculated absolute time is stored in the memory 39 (S72). .

에서

로 변환)을 예시적으로 보인 도면이다.9 is an absolute time that is converted as a dual mode mobile communication terminal moves from one base station cell n of the asynchronous network to another base station cell y.

in

Is shown as an example.

Then, when a call setup request is generated in the asynchronous standby mode (S74, S76), the dual-mode mobile communication terminal performs the call setup with the asynchronous system (S78), the WCDMA data received through the antenna and RF switch 30 Is transmitted to the application processor 38 through the WCDMA RF module 33 and the WCDMA modem 34 to perform call processing (S80).

While performing the call processing with the asynchronous system through the process S80 described above, the dual mode mobile communication terminal continuously measures the sensitivity of the signal received from the asynchronous system, but the signal sensitivity is lowered below the specified threshold, thereby handover to the synchronous system. When the specific condition for satisfying (S82) is satisfied, the dual mode mobile communication terminal requests a handover to the asynchronous system and simultaneously stores the asynchronous system and the call through the RF switch 30 in the memory. The CM mode is set based on the absolute time (S84), and the synchronization information of the synchronization system is received from the synchronization system in the CM mode operation period (S86).

Thereafter, the synchronization information received from the synchronization system in step S86 is compared with the synchronization information of the synchronization system detected in step S58 to confirm the synchronization information of the synchronization system (S88).

On the other hand, the asynchronous system that has received a handover request from the dual mode mobile communication terminal through the above-described process S84 requests the handover of the dual mode mobile communication terminal to the synchronous system, and the handover requested synchronous system according to the handover request. After allocating the resources required for call establishment, completing the path preparation, and sending the response signal for the handover request to the asynchronous system, the asynchronous system receiving the response signal for the handover request from the synchronous system is the dual mode mobile communication. The terminal transmits a handover message to the terminal to transition to the synchronization system. The handover message includes routing information necessary for call establishment with the synchronization system (for example, information corresponding to frequency, pilot, PN offset, etc. for the target cell). Is included.

On the other hand, the dual-mode mobile communication terminal confirming the synchronization information of the synchronous system through the above step S88, when receiving a handover message to transition from the asynchronous system to the synchronous system while maintaining a call with the asynchronous system (S90) The call connection with the synchronization system is completed by using the synchronization information of the synchronization system and the path setting information included in the handover message (S92), and the data received through the asynchronous system is synchronized. It is provided through (S94).

At the same time, the dual mode mobile communication terminal performs a call release procedure with the asynchronous system.

Thereafter, when a call release request occurs (S96), the dual mode mobile communication terminal terminates the call with the synchronization system and then transitions to the synchronization standby mode (S98).

The handover control method in the dual mode mobile communication terminal and the dual mode mobile communication terminal of the present invention is not limited to the above-described embodiments, and can be modified in various ways within the scope of the technical idea of the present invention.

According to the handover control method of the dual mode mobile communication terminal and the dual mode mobile communication terminal of the present invention as described above, the synchronization information of the synchronization network is obtained and stored in the idle time, and the terminal enters the synchronization network. When the synchronization information of the synchronization network is detected through the Compressed Mode (CM) mode, the synchronization information obtained from the idle time is compared with the synchronization information obtained during the idle time, and then used during transition to the synchronization network. This is not necessary.

Accordingly, the price of the terminal can be reduced, and the space for removing noise can be increased, thereby improving the call quality.

Claims (5)

A control unit for controlling the operation of the CDMA RF module, the CDMA modem, the WCDMA RF module, and the WCDMA modem; Under the control of the control unit is provided with an RF switch for applying the RF signal received through the antenna to either one of the RF module for CDMA and WCDMA, And the control unit deactivates the WCDMA RF module and the WCDMA modem for a limited time in asynchronous standby mode, and activates the CDMA RF module and the CDMA modem to detect synchronization information of a synchronous system. Detecting, by the dual mode mobile communication terminal, synchronization information of the synchronization system using time-out in asynchronous standby mode; Calculating a synchronous frame time difference between the synchronous system and the asynchronous system using the synchronous information of the synchronous system; Storing the synchronization information of the synchronization system and the synchronization frame time difference in a memory; When a call establishment request is generated in the asynchronous standby mode, establishing a call with the asynchronous system and performing call processing with the asynchronous system; During a call processing with the asynchronous system, if a handover event to the synchronous system occurs, the CM mode is set based on the synchronous frame time difference, and then the synchronous information is received from the synchronous system in the CM mode operation period. Process; Checking the synchronization information of the synchronization system by comparing the synchronization information received from the synchronization system with the synchronization information stored in the memory; When receiving a handover message to transition to the synchronous system from the asynchronous system, after setting the call with the synchronous system using the synchronization information of the identified synchronous system and the routing information included in the handover message, the synchronous system And performing a call release procedure with the asynchronous system simultaneously with performing call processing. The method of claim 2, wherein the synchronization information detection of the synchronization system, In the asynchronous standby mode, the WCDMA RF module and the WCDMA modem are deactivated for a limited time and the CDMA RF module and the CDMA modem are activated, and then the synchronization information of the synchronous system is detected. Over control method. 4. The method of claim 3, wherein if the call does not occur continuously, the synchronization information of the synchronization system is detected and updated at regular intervals. The method of claim 2, wherein when the dual mode mobile communication terminal moves between cells within an asynchronous system area, Detecting synchronization information of the moved cell; Calculating a synchronous frame time difference generated between the moved asynchronous cell and the synchronous system using the synchronous information of the synchronous system and the synchronous information of the moved cell; And storing the calculated absolute time in the memory.

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