KR100757088B1 - Multiband-Multimode terminal and intersystem handover method in the Multiband-Multimode terminal - Google Patents

Abstract

The present invention relates to a multi-band multi-mode (MB-MM) mobile communication terminal, and according to a preferred embodiment of the present invention, the first communication network and the second communication network between the first communication network and the second communication A first modem outputting a receiving end activation command in an overlay area, a second modem coupled with the second communication network to perform communication, and receiving a receiving end activation command through a control path connected to the first modem; A first high frequency processor provided at a front end of a modem and activated by the control of the second modem receiving the receiving end activation command to transmit a high frequency signal received from the second communication network to the second modem; When the received signal strength information of the signal is greater than or equal to a preset threshold, the second modem is coupled with the communication network to initiate communication A de-multi mode (MB-MM) mobile communication terminal is provided. According to the present invention, there is an effect of minimizing network discovery during handover in a multi-band-multimode (MB-MM) mobile communication terminal and preventing unnecessary power consumption due to network discovery.

 Handover, Ping-Pong Status, System Information Block Message, Received Signal Code Power

Description

Multiband-Multimode Terminal and Intersystem Handover Method in the Multiband- Method of Performing Handover Between Each Modem in a Multi-Band-M mode Mobile Terminal and a Multi-Band-M mode Mobile Terminal Multimode terminal}

1 is a diagram schematically illustrating a mobile communication network for providing a WCDMA service in a communication environment in which a CDMA network is basically constructed.

2 is a diagram of a method for performing handover from a WCDMA modem to a CDMA modem in a conventional multiband-multimode (MB-MM) mobile communication terminal.

3 is a diagram of a method for performing handover from a CDMA modem to a WCDMA modem in a conventional multi-band multi-mode (MB-MM) mobile communication terminal.

4 is a block diagram of a multi-band multi-mode (MB-MM) mobile communication terminal according to an embodiment of the present invention.

5 is a diagram of a method for performing handover from a slave modem to a master modem in a multi-band-multimode (MB-MM) mobile communication terminal according to an embodiment of the present invention.

6 is a diagram of a method for performing handover from a slave modem to a master modem in a multi-band multi-mode (MB-MM) mobile communication terminal according to another preferred embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: conventional CDMA network

110-1, 110-2, 110-3: overlay area

120-1, 120-2, 400: Multi-band multi-mode (MB-MM) mobile communication terminal

410: slave modem

420: master modem

430: slave high frequency processing unit

440: master high frequency processor

450: control path

460: slave storage unit

490: master storage unit

The present invention relates to a multiband-multimode (MB-MM) mobile communication terminal, and more particularly, to a modem in a multi-band-multimode (MB-MM) mobile communication terminal. A method for performing handover and a multi-band-multimode (MB-MM) mobile communication terminal performing the method.

The mobile communication terminal is a portable device for enabling a voice call with a counterpart located at a remote location even while moving. Initially, only a voice communication was possible, but a mobile communication terminal has evolved into a data communication method using text and symbols and a multimedia communication method including a video signal.

In general, since voice and text signals have a smaller data capacity than video signals, a code division multiple access (hereinafter referred to as 'CDMA') mobile communication system may be suitable, but a multimedia communication method including video signals Because of the large amount of data, a mobile communication system with a high data transfer rate is required. A system suitable for such a requirement is a third generation (3GPP) mobile communication system, and an example is a broadband code division multiple access (hereinafter, referred to as WCDMA) type mobile communication system.

In addition, the mobile communication terminal may be classified in various ways according to the network access method. That is, a portable terminal for voice and data communication by connecting to a CDMA mobile communication system, a portable terminal for multimedia communication by connecting to a WCDMA mobile communication system, and a multi terminal that accepts and selectively connects and communicates with both CDMA and WCDMA methods. Band-multi-mode terminals (hereinafter referred to as MB-MM terminals).

1 is a diagram schematically illustrating a mobile communication network for providing a WCDMA service in a communication environment in which a CDMA network is basically constructed.

As shown in FIG. 1, CDMA-type services are currently provided in a wide range of areas 100, but WCDMA-type services are provided in some regions 110-1, 110-2, 110-3, and CDMA-type service regions. Collectively referred to as '110'). Thus, some regions within the CDMA coverage area may overlap with the WCDMA coverage area, which is referred to as overlay area 110. Of course, the WCDMA service area may exist independently in an area other than the CDMA service area.

The overlay area 110 is a form in which a CDMA network, a second generation mobile communication network, and a WCDMA network, a third generation mobile communication network, coexist. Therefore, in order to be able to selectively use the WCDMA service and the CDMA service in the overlay area 110, the user includes both a CDMA modem and a WCDMA modem, and selectively operates between the modems. Band-multi-mode (MB-MM) mobile communication terminal (120-1, 120-2, hereinafter referred to as '120') should be provided.

Therefore, when a user moves between a WCDMA network and a CDMA network in a process of using a multi-band multi-mode (MB-MM) mobile communication terminal 120, each method of the terminal for providing a continuous service. Handover between modems is required. However, since WCDMA and CDMA are different communication methods, it is very difficult to implement handover between modems of each method. It is also a question of when to start and stop the two modems. In addition, if the multi-band multi-mode (MB-MM) mobile communication terminal 120 does not move in the overlay area, handover between the modems is repeated. This state is called a ping pong state.

Hereinafter, a method for performing handover and a ping pong state in a conventional multiband-multimode (MB-MM) mobile communication terminal will be described with reference to FIGS. 2 and 3.

2 is a diagram illustrating a method for performing handover from a conventional WCDMA modem to a CDMA modem in a multi-band-multimode (MB-MM) mobile communication terminal.

Referring to FIG. 2, a WCDMA modem is initially initialized and driven (step 210).

In step 220, the WCDMA modem receives a Received Signal Code Power (RSCP) value from the network through a System Information Block message (eg, SIB3 or SIB4) message.

In step 230, the received signal code power (RSCP) value of the system information block message received by the WCDMA modem is compared with a preset threshold value.

In step 240, if the received signal code power is smaller than the threshold as a result of the comparison, the handover is performed from the WCDMA modem to the CDMA modem, otherwise the handover is not performed.

3 is a flowchart illustrating a method for performing handover from a conventional CDMA modem to a WCDMA modem in a multi-band-multimode (MB-MM) mobile communication terminal.

Referring to FIG. 3, the CDMA modem is initialized and driven (step 310).

In step 320, the CDMA modem receives a system parameter message (SPM) from the network.

In operation 330, the CDMA modem determines whether the CDMA modem is located in the overlay area 110 based on the BASE_CLASS of the system parameter message.

In step 340, if it is located in the overlay area 110 as a result of the determination in step 330, a handover from the CDMA modem to the WCDMA modem is performed. Otherwise, the handover is not performed. This is a method for unconditionally performing a handover to a WCDMA modem when the multi-band-multi-mode (MB-MM) mobile communication terminal 120 is located in the overlay area 110. If a video signal is included, WCDMA communication is performed. This method is to use the WCDMA communication method if possible because of the high data transfer speed.

When performing the handover according to the above-described conventional invention in the multi-band multi-mode (MB-MM) mobile communication terminal 120, the multi-band multi-mode (MB-MM) mobile communication terminal in the overlay area 110 If 120 does not move, a ping pong state may occur. That is, when the multi-band multi-mode (MB-MM) mobile communication terminal 120 does not move in the overlay area 110, the WCDMA modem receives the received signal code power smaller than the threshold and the CDMA modem is received. After performing the handover, if the CDMA modem receives the system parameter message of the overlay area from the network, the CDMA modem will perform the handover to the WCDMA modem again and repeat this operation. That is, it will be in a ping pong state.

To eliminate this phenomenon, after performing the handover from the WCDMA modem to the CDMA modem by setting the BACK_OFF TIME, the WCDMA network is disconnected only at a certain time interval (ie, back off time). A way to navigate is devised.

However, although the ping-pong state of the terminal may be temporarily improved in the above-described method of setting the backoff time, the backoff time (BACK_OFF) in the overlay area 110 after the handover is performed from the CDMA modem to the WCDMA modem. If no movement is made during TIME), the ping-pong state continues. That is, after a certain time of backoff time after performing a handover from a CDMA modem to a WCDMA modem, the WCDMA modem searches for a network. The multiband-multimode (MB-MM) mobile communication Since the terminal 120 does not move in the overlay area 110, the received signal code power value is weaker than the preset threshold. Therefore, handover is performed again with the CDMA modem.

As a result, unnecessary battery consumption for network search occurs even while staying only in the CDMA network, and in particular, an incapacity state occurs during the network search process. In addition, there is a problem that can not perform a text message (SMS) reception or other additional services.

Accordingly, the present invention provides a multi-band multi-mode (MB-MM) mobile communication terminal and a multi-band multi-mode (MB-MM) mobile communication terminal that can effectively prevent the ping-pong state that may occur during handover It is intended to provide a method for performing handover between modems.

In addition, the present invention is a multi-band multi-mode (MB-MM) mobile communication terminal to minimize the network search during the handover, and to prevent unnecessary power consumption due to the network search multi-band multi-mode (MB-MM) The present invention provides a method for performing handover between each modem provided in a mobile communication terminal and a multi-band-multimode (MB-MM) mobile communication terminal.

Other objects of the present invention will be readily understood through the following description.

In order to achieve the above objects, there is provided a multi-band multi-mode (MB-MM) mobile communication terminal according to an aspect of the present invention.

According to an exemplary embodiment of the present invention, a first modem for outputting a receiving end activation command in the case of an overlay area between the first communication network and the second communication network while performing communication with the first communication network, combining with the second communication network And a second modem and a front end of the second modem to receive communication through the control path connected to the first modem, and to control the second modem receiving the receiving end activation command. A first high frequency processor configured to be activated and transmit a high frequency signal received from the second communication network to the second modem, wherein the received signal strength information of the high frequency signal is greater than or equal to a pre-stored threshold; Performing a handover to a second modem so that the second modem is combined with the second communication network to initiate communication; A band-multi mode (MB-MM) mobile communication terminal is provided.

The second modem may determine whether the received signal strength information is greater than or equal to the previously stored threshold value.

The first modem may determine whether the received signal strength information of the high frequency signal received from the second modem through the control path is greater than or equal to the previously stored threshold value.

In the multi-band multi-mode (MB-MM) mobile communication terminal, further comprising a second storage unit connected to the second modem for storing the various parameters required for the second modem to perform communication, The threshold value stored in advance may be stored in the second storage unit.

In the multi-band multi-mode (MB-MM) mobile communication terminal, further comprising a first storage unit connected to the first modem for storing the various parameters required for the first modem to perform communication, The previously stored threshold value may be stored in the first storage unit.

The handover may be characterized as an idle handover.

In the multi-band multi-mode mobile communication terminal, the first modem and the second modem may be coupled to the first communication network and the second communication network only during the handover. .
In addition, when the handover is completed, the second modem may transmit a handover completion signal for terminating driving of the first modem to the first modem.

In order to achieve the above objects, a method for performing handover according to another aspect of the present invention is provided.

According to another aspect of the present invention, in a method for performing handover between modems in a multi-band-multimode (MB-MM) mobile communication terminal, a current location is obtained by using a system parameter message received by the first modem from the first communication network. Determining whether is an overlay area, and if the determination result is an overlay area, transmitting, by the first modem, a receiving end activation command to drive a high frequency processor for processing a high frequency signal received from a second communication network to the second modem; Extracting received signal strength information of a second communication network by using the processed high frequency signal received from the high frequency processor that controls the second modem to be activated, and transmitting the received signal strength information to the first modem; A first modem compares the received signal strength information with a preset threshold, Inputting a start command to the first modem for the first modem to initiate communication with the second modem when the information is above the threshold value and when the first modem receives a handover complete signal from the second modem; There is provided a handover performing method comprising the step of terminating driving.

The pre-stored threshold value may be stored in a storage unit connected to the first modem.

The first modem and the second modem are mutually coupled by a control path, and the receiving end activation command, the received signal strength information, the driving start command, and the handover complete signal are transmitted through the control path. can do.

The handover may be characterized as an idle handover.

In order to achieve the above object, there is provided a handover method according to another aspect of the present invention.

According to another aspect of the present invention, in a method for performing handover between modems in a multi-band-multimode (MB-MM) mobile communication terminal, the first modem is currently using a system parameter message received from the first communication network. Determining whether the location is an overlay area, and if the determination result is an overlay area, transmitting, by the first modem, a receiving end activation command to drive a high frequency processor for processing a high frequency signal received from a second communication network to a second modem; Extracting received signal strength information of a second communication network by using the processed high frequency signal inputted from the high frequency processor that controls the second modem to be activated, and comparing the received signal strength information with a preset threshold value; and When the received signal strength information is greater than or equal to the threshold value, the second modem contacts the second communication network. It discloses a communication and, if the handover is complete, the handover method comprises the step of sending a handover complete signal to the driving end of the first modem to the first modem is provided.

The pre-stored threshold value may be stored in a storage unit connected to a second modem.

The second modem and the first modem may be mutually coupled by a control path, and the receiving end activation command and the handover completion signal may be transmitted through the control path.

The handover may be characterized as an idle handover.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Ordinal numbers (eg, first and second) added to distinguish the same or similar components in the present specification are merely added in the order in which each component is described for each paragraph or description. Note that this is not intended to specify the name of each component or to limit the scope of rights.

The following merely illustrates the principles of the invention. Therefore, those skilled in the art, although not explicitly described or shown herein, can embody the principles of the present invention and invent various methods and apparatus using the same that are included in the concept and scope of the present invention. In addition, it is to be understood that all detailed descriptions, including the principles, aspects, and embodiments of the present invention, as well as listing specific embodiments, are intended to include structural and functional equivalents.

In addition, the multi-band multi-mode (MB-MM) mobile communication terminal for the convenience of the following description is shown in the description and drawings with reference to the embodiment provided with a master modem and a slave modem one by one, multi-band multi-mode (MB-MM) The mobile communication terminal may be provided with two or more slave modems.

In addition, for convenience of the following description, the first modem is defined as a master modem and the second modem is defined as a slave modem, but is not limited to functional terms of master and slave.

4 is a block diagram of a multi-band multi-mode (MB-MM) mobile communication terminal according to an embodiment of the present invention.

As shown in FIG. 4, the multi-band-multimode (MB-MM) mobile communication terminal 400 according to an exemplary embodiment of the present invention includes a slave modem 410, a master modem 420, and a slave high frequency processor ( 430, a master high frequency processor 440, a control path 450, a slave storage unit 460, an antenna 470, a duplexer 480, and a master storage unit 490. In addition, the display unit may further include an input unit.

The slave modem 410 may be a CDMA modem. The slave modem 410 is a multiband-multimode (MB-MM) mobile communication terminal when operating in the slave mode (that is, the mode in which communication is performed by the slave modem 410), various kinds of baseband (BASE BAND) It is responsible for signal processing and control. In particular, when the slave modem 410 is a CDMA modem, it is determined whether the overlay modem 110 is based on a base class BASE_CLASS of a system parameter message (SPM) received from a CDMA network. do. If it is determined as the overlay area 110, a signal for driving the master high frequency processor 440 through the control path 450 (hereinafter, referred to as a receiver active command) is transmitted. The receiving end activation command is input to the master modem 420, and the master modem 420 drives the master high frequency processor 440 according to the receiving end activation command. Also, the received signal strength information received from the master modem 420 through the control path 450 is compared with a threshold stored in the slave storage unit 460 or the master storage unit 490. In this case, when the slave modem 410 compares the received signal strength information with the threshold value stored in the master storage unit 490, the control path 450 controls both the received signal strength information and the threshold value from the master modem 420. Must be sent via

As a result of the comparison, if the received signal strength information is greater than the threshold value, a signal for driving the master modem 420 (hereinafter, referred to as a “drive start command”) is transmitted to the master modem 420 for handover to the master method.

Here, the comparison between the received signal strength information and the stored threshold may be performed by the slave modem 410 or may be performed by the master modem 420. In addition, when the master modem 420 executes the master modem 420, if the comparison result is larger than the stored threshold value, the master modem may start driving for handover. That is, the slave modem 410 does not need to transmit a start command to the master modem 420.

The master modem 420 may be a WCDMA modem. The master modem 420 is a baseband when the multi-band-multimode (MB-MM) mobile communication terminal 400 operates in a master mode (that is, a mode in which communication is performed by the master modem 420). It is in charge of various signal processing and control. In particular, upon receiving the receiving end activation command from the slave modem 410, the receiving end of the master high frequency processor 440 is activated. Also, the received signal strength information is detected from the information received from the master high frequency processor 440 and transmitted to the slave modem 410. The received signal strength information may be included in a system information block message (eg, SIB3 or SIB4) message. In addition, the received signal strength information may be a received signal code power (RSCP) value included in the system information block message. In addition, upon receiving the start command from the slave modem 410, the modem is driven and performs a handover. Here, the comparison between the received signal strength information and the stored threshold value may be performed by the slave modem 410 and may be performed by the master modem 420 as described above. In addition, when comparing the received signal strength information and the threshold in the master modem, the received signal strength information received through the master high frequency processor 440 and the threshold stored in the slave storage unit 460 or the master storage unit 490 in advance. In comparison, when the received signal strength information is large, the master modem 420 may start driving for handover. In this case, when the threshold value is stored in the slave storage unit 460, the threshold value must be transmitted through the control path 450 from the slave modem 410 to compare the received signal strength information with the threshold value.

In addition, when the handover is normally completed, the master modem 420 transmits a signal indicating that the handover is completed (hereinafter, referred to as a handover completion signal) to the slave modem 410.

The slave high frequency processor 430 includes a receiver for processing a signal received from the network and a transmitter for processing a signal transmitted from the slave modem 410 to the network, and the slave modem 410 amplifies a signal transmitted to the network. It handles a variety of high frequencies in the slave mode to be transmitted and received. In particular, when the slave modem 410 is a CDMA modem, the slave modem 410 receives a system parameter message (SPM) from the CDMA network and delivers it to the slave modem 410.

The master high frequency processor 440 includes a receiver for processing a signal received from the network and a transmitter for processing a signal transmitted from the master modem 420 to the network, and the master modem 420 amplifies a signal transmitted to the network. It processes various high frequencies of the master mode transmitted and received. In particular, when the master modem 420 is a WCDMA type modem, a system information block (eg, SIB3 or SIB4) message is received from the WCDMA type network. In addition, when the multi-band multi-mode (MB-MM) mobile communication terminal 400 is operating in the slave mode, the driving is terminated and the slave modem 410 is the master modem in the overlay region 110. It is driven by the control of the master modem 420 by the receiving end activation command sent to 420. Of course, it can also be driven by the control of the master modem 420 not by the receiving end activation command.

The control path 450 is formed by the control pins of the slave modem 410 and the master modem 420, thereby receiving received signal strength information (eg, between the slave modem 410 and the master modem 420). Receiving signal code power, etc.), receiving end active command and driving start command, and the like.

The slave storage unit 460 is connected to the slave modem 410 and stores various parameters for communication of the slave modem 410. In particular, the threshold value for comparing with the received signal strength information received from the master high frequency processor 440 is stored.

The master storage unit 490 is connected to the master modem 420 and stores various parameters for communication of the master modem 420. In particular, when the master modem compares the received signal strength information received from the master high frequency processor 440 with a threshold, the corresponding threshold is stored.

In addition, the antenna 470 transmits and receives signals from the multi-band-multi-mode (MB-MM) mobile communication terminal 400 and the slave and master mode networks, and the duplexer 480 is a different high frequency of each mode Separate the bands.

5 is a flowchart illustrating a method for performing handover from a slave modem to a master modem in a multi-band-multimode (MB-MM) mobile communication terminal according to an embodiment of the present invention. 6 is a flowchart illustrating a method for performing handover from a slave modem to a master modem in a multi-band multi-mode (MB-MM) mobile communication terminal according to another embodiment of the present invention.

In this case, it is assumed that the slave modem 410 is a CDMA modem and the master modem 420 is a WCDMA modem. In this case, the master modem 420 is in a state in which only a function for performing communication is terminated. In this case, the driving for performing other functions is activated. Of course, it is obvious that each of the above modems can be replaced by modems of other communication methods such as TDMA and GSM, respectively.

Hereinafter, when handing over from the slave modem 410 to the master modem 420 in the multi-band multi-mode (MB-MM) mobile communication terminal 400 according to an embodiment of the present invention with reference to FIG. This section describes how to resolve the incapacity condition that occurs.

Referring to FIG. 5, a multi-band-multimode (MB-MM) mobile communication terminal 400 located in a CDMA service area has a slave modem 410 initialized to perform communication by CDMA. Is being driven (step 505). The idle state refers to a state in which the terminal is driven and operates but does not make a call, that is, a call waiting state. In this idle state, the multi-band-multimode (MB-MM) mobile communication terminal 400 performs handover between the modems.

In step 510, the slave modem 410 receives the overlay area information from the network. In particular, when the slave modem 410 is a CDMA modem, it receives a system parameter message (SPM) from the network.

In step 515, the slave modem 410 uses the base class (BASE_CLASS) of the received system parameter message (SPM) to transmit the multiband-multimode (MB-MM) mobile communication terminal 400 to the current overlay area 110. Determine if it is located.

In step 520, if it is determined that the multi-band multi-mode (MB-MM) mobile communication terminal 400 is located in the overlay area 110, the slave modem 410 uses the master high frequency processor 440 as the master modem 420. Send a receive end activation command to activate. When the multi-band-multi-mode (MB-MM) mobile communication terminal 400 is operating in the slave mode, the master modem 420 stops driving the communication function and the master high frequency processor 440 stops driving. Power consumption can be minimized. Therefore, before performing the handover, that is, before the communication by the master modem 420, the slave modem 410 through the control path 450 to the master modem 420 to drive the master high frequency processor 440 first. In step 525, the master modem 420 transmits the receiving end driving command to the master high frequency processor 440 when receiving the receiving end activation command.

In operation 530, the master high frequency processor 440 first drives only the receiving end by the receiving end driving control command, and receives a system information block message from the network and transmits the received system information block message to the master modem 420. The reason for activating only the receiving end first is to minimize power consumption.

In operation 535, the master modem 420 extracts the received signal strength information from the received system information block message and transmits the received signal strength information to the slave modem 410 through the control path 450. The received signal strength information may be a received signal code power (RSCP) value of the system information block message (SIB3 or SIB4).

In operation 540, the slave modem 410 receives the received signal strength information and compares it with a preset threshold. In this case, the threshold value is stored in the slave storage unit 460 connected to the slave modem 410.

In step 545, if the received signal strength information is greater than or equal to the threshold value, it performs a handover from the slave modem 410 to the master modem 420 so that the multi-band-multimode (MB-MM) mobile communication terminal 400 performs the handover. This means that the received signal strength is sufficient to operate in the master mode. Therefore, the slave modem 410 transmits a start command to the master modem 420 to perform the handover. On the contrary, if the received signal strength information is smaller than the threshold, it means that the current network exists but the strength of the signal is weak. Accordingly, the multiband-multimode (MB-MM) mobile communication terminal 400 maintains the slave mode without performing a handover to prevent a communication failure due to the conventional ping-pong state. At this time, the slave modem 410 is performed again from the step 510. In this case, since the receiving end of the master high frequency processor 440 is already activated, the receiving modem activation command transmitted by the slave modem 410 to the master modem 420 is performed. It is apparent that step 520 of transmitting the step and step 525 of the master modem 420 transmitting the receiving end driving control command to the master high frequency processor 440 may be omitted. In addition, when the received signal strength information is less than the threshold value, the slave modem 410 transmits a signal for terminating driving of the receiving end of the master high frequency processor 440 to the master modem 420 to control the master modem 420. It will be apparent to those skilled in the art that the method may include the step of driving the receiving end of the master high frequency processor 440 again.

In operation 550, the master modem 420 receives a driving start command and starts driving. The master modem 420 transmits a transmission end activation command for activating the transmission end of the master high frequency processor 440 to the master high frequency processor 440 (step 555). ).

When the master high frequency processor 440 is activated by the transmitter driving control command, the master modem 420 starts a handover operation (step 565). The process of performing the handover is apparent to those skilled in the art, and a detailed description thereof will be omitted.

When the handover is normally completed (ie, the master modem 420 completes normal registration with the network), the master modem 420 transmits a handover complete signal to the slave modem 410 (step 570). Upon receiving the handover complete signal, the slave modem 410 transmits an acknowledgment (ACK) signal to the master modem 420 (step 575), and terminates the operation (step 578). Thereafter, only the master modem 420 which has received the response signal will operate normally (step 585).

Hereinafter, a method of performing handover from a slave modem to a master modem in a multi-band-multimode (MB-MM) mobile communication terminal according to another preferred embodiment of the present invention will be described. This is different from the exemplary embodiment described above with reference to FIG. 5 in that the subject comparing the received signal strength information and the threshold is the master modem 420 instead of the slave modem 410. Therefore, this will be described with emphasis.

Steps 605 to 630 are the same as or similar to steps 505 to 530 described above. Further, step 650 to step 685 are the same as or similar to step 550 to step 585 described above. Therefore, detailed descriptions of steps 605 to 630 and steps 650 to 685 are omitted here, and only the steps 635 and 640 are described (see steps 505 to 530 and 550 to 585 described above). ).

In operation 635, the master modem 420 extracts received signal strength information from the system information block received from the master high frequency processor 440. Since the master modem 420 compares the received signal strength information with the threshold, the master modem 420 does not need to extract the received signal strength information and transmit it to the slave modem 410.

In operation 640, the master modem 420 compares the extracted received signal strength information with a preset threshold. In this case, the threshold value may be stored in the master storage unit 490. If the threshold value is stored in the slave storage unit 460, the threshold value may be received from the slave modem 410 through the control path 450. The master modem 420 does not perform communication while the multi-band-multimode (MB-MM) terminal is operating in the slave mode, and is driving to perform other operations. Thus, master modem 420 may perform step 640.

When the received signal strength information is larger than the threshold value, the master modem 420 starts driving for signal exchange with the network to perform a handover (step 650), where the master modem 420 determines whether to start driving. As it is determined, it is obvious that the slave modem 410 does not need to transmit a start command to the master modem 420.

As described above, in the multi-band multi-mode (MB-MM) mobile communication terminal according to the present invention, a method for performing handover between modems and a multi-band multi-mode (MB-MM) mobile communication terminal performing the method Therefore, there is an effect that can effectively prevent the ping-pong state that may occur during handover.

In addition, the present invention has the effect of minimizing network discovery during handover and preventing unnecessary power consumption due to network discovery in a multi-band-multimode (MB-MM) mobile communication terminal.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be appreciated that modifications and variations can be made.

Claims (16)

A first modem coupled to a first communication network and outputting a receiving end activation command in an overlay area between the first communication network and the second communication network while performing communication; A second modem coupled to the second communication network to perform communication and receiving the receiving end activation command through a control path connected to the first modem; And A first high frequency processor provided in front of the second modem and activated by the control of the second modem receiving the receiving end activation command to transmit a high frequency signal received from the second communication network to the second modem; , The second modem compares the received signal strength information of the high frequency signal with a previously stored threshold value and performs a handover from the first modem to the second modem when the received signal strength information is greater than or equal to the threshold value. 2 A multiband-multimode (MB-MM) mobile communication terminal in which a modem initiates communication through the second communication network. delete delete The method of claim 1, It is connected to the second modem, further comprising a storage unit for storing various parameters required for the second modem to perform communication, And the pre-stored threshold value is stored in the storage unit. delete The method of claim 1, The handover is a multi-band multi-mode (MB-MM) mobile communication terminal, characterized in that the idle handover (Idle Handover). The method of claim 6, And the first modem and the second modem are coupled to the first and second communication networks, respectively, only during the handover. delete delete delete delete A method for performing handover between modems in a multi-band-multimode mobile communication terminal, The first modem determines whether the current location is an overlay area by using a system parameter message received from the first communication network. If the determination result is an overlay area, the first modem processes the high frequency signal received from the second communication network. Transmitting a receiving end activation command to drive the processing unit to the second modem; Receiving, by the second modem, the receiving end activation command to drive the high frequency processing unit, and extracting received signal strength information on the second communication network using the high frequency signal received from the high frequency processing unit; Comparing, by the second modem, the received signal strength information with a preset threshold; And When the received signal strength information is greater than or equal to the threshold value, a second modem is connected to the second communication network to initiate communication, and when a handover is completed, a handover complete signal for terminating driving of the first modem is received. And performing the handover to the modem. The method of claim 12, The pre-stored threshold is stored in a storage unit connected to the second modem. delete The method of claim 12, The handover is a handover method, characterized in that the idle handover (Idle Handover). The method of claim 1, And the second modem transmits a handover complete signal to the first modem to terminate driving of the first modem when the handover is completed.

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