KR20060110066A - Effective roaming method between two mobile communication modes and the dual mode terminal therefor - Google Patents

Abstract

A method for effectively performing roaming between different mobile communication modes and a dual mode terminal therefor are provided to minimize time taken for roaming without using a timer for counting time estimated for preparing roaming. A CDMA modem(310) processes signals transmitted/ received to/from the first communication network. A WCDMA modem(320) transmits/receives packets through a communication path connected with the CDMA modem(310) and processes signals transmitted/received to/from the second communication network. A controller(340) checks whether a mobile terminal is roamed at a position where communication is possible with the CDMA modem(310). When the terminal moves to a communication available area, the controller(340) turns on the WCDMA modem(320). When the WCDMA modem(320) is ready for roaming, the controller(340) connects a switch connected with the CDMA modem(310) to the WCDMA modem(320) to perform a mode according to the WCDMA modem(320).

Description

EFFECTIVE ROAMING METHOD BETWEEN TWO MOBILE COMMUNICATION MODES AND THE DUAL MODE TERMINAL THEREFOR}

1 is a diagram illustrating an area in which a general CDMA network and WCDMA network systems are installed;

2 is a block diagram illustrating an internal dual mode terminal;

3 is a signal flow diagram illustrating each component according to general roaming;

4 is an internal block diagram of a dual mode terminal according to an embodiment of the present invention;

5 is a diagram illustrating a packet structure transmitted and received between a WCDMA modem and a CDMA modem according to an embodiment of the present invention;

6 is a diagram for explaining types of messages transmitted and received between different modems according to an embodiment of the present invention;

7 is a flow chart of message transmission and reception between two different modems when roaming according to an embodiment of the present invention.

The present invention relates to an efficient roaming method between different mobile communication methods for minimizing waiting time when roaming between communication networks providing communication services using different mobile communication technologies, and a dual mode terminal for the same.

Currently, Code Division Multiple Access (CDMA) systems are already extensively serviced and fully equipped with infrastructure. However, third-generation networks such as Wideband Code Division Multiple Access (WCDMA) systems are gradually introduced to provide services that cannot be supported in second-generation networks such as CDMA systems. In the area where the 3G network is installed while utilizing the infrastructure of the 2G network, a dual mode terminal designed to receive specialized services of the 3G network has been developed.

In recent years, dual mode user equipment or dual mode mobile terminals which simultaneously support WCDMA and CDMA have been developed due to the necessity of providing a user with a mobile terminal capable of operating in both technologies (WCDMA and CDMA). Developed. One dual-mode terminal having these two modes requires various technologies that are optimally compatible with the two modes. Among these techniques, there is a technique related to roaming which is required when switching between WCDMA mode and CDMA mode in a terminal.

In general, the roaming function allows a dual-mode terminal to switch between CDMA and WCDMA modes, such as switching to CDMA mode when the dual mode terminal operates in WCDMA mode in a region where WCDMA service is available. Next, roaming in a region where general CDMA network and WCDMA network systems are installed will be described with reference to FIG. 1. 1 is a diagram illustrating an area in which general CDMA network and WCDMA network systems are installed. Referring to FIG. 1, a region in which general CDMA network and WCDMA network systems are installed is largely divided into a CDMA exclusive region that can only support CDMA services and an overlapping region that can support WCDMA services as well as CDMA services.

Since the dual mode terminal 100 operates in the WCDMA mode in the WCDMA network, that is, the overlapping region 160 and enters the CDMA exclusive region 150, the WCDMA base station is not found. Therefore, when the CDMA base station is found, the CDMA base station is found. Switch to mode to complete roaming. On the contrary, when entering the overlapping region 160, the dual mode terminal 100 operating in the CDMA mode roams to switch back to the WCDMA mode according to a predetermined condition.

As such, the dual mode terminal supporting the CDMA mode and the WCDMA mode has a configuration as shown in FIG. 2. FIG. 2 is a block diagram illustrating a general dual mode terminal. Referring to FIG. 2, the dual mode terminal 100 generally includes a CDMA module 110, a WCDMA module 120, a switch 130, and a controller 140. It is configured to include. Each module consists of a corresponding modem (not shown) and an RF unit (not shown). Each terminal supporting WCDMA and CDMA modes uses a modem chip supporting different mobile communication services according to the corresponding mode. do. Here, each module is connected to the control unit 140 which is an application processor through a hardware communication path. And the communication port of the control unit 140 is selectively connected to each module (110, 120) using a switch 130. Accordingly, the control unit 140 and each module 110 and 120 correspond to 1: 1 through this port, and while one modem is operating, the other modems are powered off to prevent power consumption.

As described above, since the control unit 140 is selectively connected through the modem and the switch 130 of each module 110 and 120, when the terminal 100 is operating in any one mode, the other mode may be You will not be able to communicate with the modem. Therefore, if one mode is used continuously, it is efficient to turn off the modem in the other mode.However, when repeatedly roaming in the roaming congestion zone, the roaming time is long when switching between the modes and at the same time, it is an internal problem. May occur.

As described above, the operation of each component inside the terminal according to roaming is performed. To this end, reference is made to FIG. 3, which shows a signal flow diagram between components according to a general roaming operation.

As shown in FIG. 3, in order to operate in the WCDMA mode and roam to the CDMA mode, the WCDMA module 120 performs the initialization to start roaming in step 200, proceeds to step 210, and requests to turn on the power of the CDMA module. The command is transmitted to the controller 140. Then, in response to the request from the WCDMA module 120, the controller 140 transmits a command to power on the CDMA module to the CDMA module 110 in step 220. Then, the control unit 140 determines whether a predetermined time has elapsed in step 230, and releases the switch connection so that the connection with the WCDMA module 120 is disconnected in step 240 after a predetermined time, and instead the CDMA module 110 in step 250. Set up the switch connections so that they can be connected. When the connection with the CDMA module 110 is completed through this, the controller 140 turns off the power of the WCDMA module in step 260.

As described above, in order to roam to another mode, the control unit turns on the target modem to roam and disconnects from the existing modem when the target modem operates. The switch must be connected to the target modem. However, even if the control unit issues a command to turn on the target modem, the control unit does not have a problem of accurately determining when the target modem operates because it is not connected to the target modem through a switch. Accordingly, in the related art, the estimated time until the target modem is powered on and ready for roaming is roughly estimated, and the controller uses a timer to connect the switch to the target modem after the estimated time. In particular, roaming time must be set longer than the actual roaming time for more stable roaming, so an estimated roaming time of approximately 3 to 4 seconds should be set. Therefore, this method is not only very inconvenient for the user who has to wait on the standby screen state for the estimated estimated roaming time, but also does not accurately grasp what problem occurs when roaming.

Accordingly, the present invention provides an efficient roaming method between different mobile communication methods and a dual mode terminal for the same to minimize the time taken when roaming between communication networks providing communication services using different mobile communication technologies.

In addition, the present invention is an efficient roaming method between different mobile communication methods to operate in one mode in a terminal supporting different mobile communication services to control the modem of the other mode to enable faster and more accurate roaming to the mode And it provides a dual-mode terminal for this.

In order to accomplish the above, a dual-mode terminal for performing efficient roaming between a first communication network and a second communication network according to the present invention includes a first modem for processing signals transmitted and received from the first communication network, and connected to the first modem. A second modem that transmits and receives a packet through a communication path, processes signals transmitted and received from a second communication network, and determines whether to roam at a location that can communicate with the first modem and moves to an area where the second modem can communicate. If it is determined that the second modem is powered on, the second modem detects whether it is ready to roam, and when it is completed, the switch connected to the first modem to the second modem by connecting to the second modem connected It characterized in that it comprises a control unit for performing a mode according to.

In addition, the present invention provides an efficient roaming method in a dual-mode terminal having a first modem and a second modem capable of communicating in a different mobile communication method, from the first communication network at a position capable of communicating with the first modem. Determining whether to roam according to the received signal; when roaming is started; powering on the second modem; and whether the second modem is ready to roam through a communication path connecting the modems. And determining, and if the determination result is completed, roaming off the power of the first modem and performing communication through the second modem.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same elements in the figures are represented by the same numerals wherever possible. In addition, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention implements a function for efficiently roaming between communication networks providing communication services using different mobile communication technologies. To this end, the present invention provides a connection between each modem in addition to a communication path 1: 1 connected only between the control unit and each modem in a terminal including a corresponding modem for supporting the CDMA mode and the WCDMA mode, and a control unit which is a modem and one application processor. Set the path to connect to. By connecting each modem as described above, the remaining modems can be controlled through the connection path even when the modem is not operated in the mode of the modem, thereby enabling fast and accurate roaming.

The components of the dual mode terminal to which the present invention is implemented and the operation thereof will be described with reference to FIG. 4. 4 is an internal block diagram of a dual mode terminal according to an embodiment of the present invention.

First, the dual mode terminal 300 supporting the CDMA mode and the WCDMA mode is composed of a CDMA modem 310, a WCDMA modem 320 and a control unit 340 for controlling them according to the mode. . Each of these modems 310 and 320 is connected to the control unit 340 through a hardware communication path. At this time, the communication port of the controller 340 has a configuration that is selectively connected to any one of the CDMA modem 310 or the WCDMA 320 by using the switch 330. As such, the controller 340 and each of the modems 310 and 320 correspond to 1: 1 through the switch 330. When one modem is connected through the switch 330, the other modem is Power off to avoid unnecessary power consumption.

Specifically, the dual mode terminal 300 has a configuration as shown in FIG. 4, wherein the terminal 300 includes an antenna 390 for transmitting and receiving a CDMA signal and a WCDMA signal, a CDMA signal and a WCDMA transmitted and received through the antenna terminal. The duplexer 380 separating the signal, the respective RF units 360 and 370 for processing the CDMA signal and the WCDMA signal, and the signals transmitted and received to the respective RF units 360 and 370 are processed into the corresponding processing module. To each of the modems 310 and 320 for processing through the controller, the switch 330 for communication between the controller 340 and each of the modems 310 and 320, and the controller 340 which is a multimedia chip for processing data transmitted and received. Is done. In particular, according to the present invention, a communication path 350 for directly connecting the CDMA modem 310 and the WCDMA modem 320 is implemented in the terminal 300. The communication path 350 serves as a path through which packets transmitted and received between each modem are transferred. At this time, the CDMA modem 310 and the WCDMA modem 320 may be a modem chip consisting of a single chip or a DSP within the chip.

In addition, the dual-mode terminal 300 in FIG. 4 is an example of implementing the respective components required in the case of a single antenna. Therefore, when the terminal 300 having such a configuration is located in the WCDMA network, the CDMA RF 360 and the CDMA modem 310 are temporarily turned off. In contrast, the antenna 390 and the duplexer 380 Since the WCDMA RF 370 and the WCDMA modem 320 are in a power-on state, the WCDMA modem 320 is connected to the control unit 340 and the switch 330 so that the terminal 300 operates in the WCDMA mode. In addition, when the terminal 300 is located in the CDMA network, the power supply state is changed as described above to operate in the CDMA mode.

Meanwhile, in order to roam, both modems 310 and 320 should be in a power-on state. In the present invention, a CDMA modem (in addition to a communication path using a switch 330 between the controller 300 and each of the modems 310 and 320) may be used. 310 implements a new communication path 350 connecting the WCDMA modem 320. By using the communication path 350, it is possible to minimize the waiting time when roaming, and also operate in one mode and control a modem in another mode so that roaming to the corresponding mode can be performed more quickly and accurately.

In addition, the modems 310 and 320 according to the present invention internally control a transmission / reception through the control unit 240 and the switch 330 to perform a task for performing an interface and a communication path 350 between each other. Each task is provided to control the transmission and reception through the interface. The task of performing an interface with the controller 340 and the task of performing an interface between each modem operate independently of each other. For example, when the task for the controller interface exchanges data with the controller 340 in the CDMA modem 310, the task for the modem interface passes the data to the WCDMA modem 320, which is the other modem, through the communication path 350. You can also pass it. This independent task allows the controller to deliver the desired data through the communication path between the modems, even if the modems operate without the switch connected.

In the following description, an operation process performed through a communication path between two modems at the time of roaming will be described.

First, a protocol according to the present invention is defined for communication between two modems. As an example, the two modems communicate commands with each other via a packet having a structure as shown in FIG. 5 is a diagram illustrating a packet structure transmitted and received between a WCDMA modem and a CDMA modem according to an embodiment of the present invention.

Referring to FIG. 5, a header indicates a type of a packet to be transmitted and received and its size is 1 byte to distinguish up to 255 types of messages. Length has a maximum value of 2 bytes and represents the actual data size. Then, data represents data according to a packet and its size is variable and is limited to a maximum of 65535 bytes.

Meanwhile, when headers of messages exchanged with each other in a WCDMA modem and a CDMA modem for roaming may be expressed as shown in Tables 1 and 2, respectively.

Table 1 shows the contents of the packet header for giving information from the WCDMA modem to the CDMA modem, and Table 2 shows the contents of the packet header for giving information from the CDMA modem to the WCDMA modem.

According to an embodiment of the present invention, a message transmitted and received between different modems using such a packet may be defined as shown in FIG. 6. For example, the INF 500 message is an abbreviation of Inform and refers to a message for notifying another modem of its modem chip status, and the ACK 510 message is an acknowledgment acknowledgment message and is a response message to the INF message. ) Is an abbreviation of Command and is a command message indicating an operation command transmitted from one modem chip to another modem chip, and the RSP 530 message is an abbreviation of Response and transmits a result of the operation command.

Next, a process of transmitting and receiving a mutual message when roaming from WCDMA to CDMA through a communication path according to the present invention using the above definition will be described with reference to FIG. 7. 7 is a flowchart illustrating message transmission and reception between two different modems when roaming according to an exemplary embodiment of the present invention.

The roaming process according to the present invention turns on the target modem to be roamed through the communication path connecting the inter-modem chips at the time when roaming is required, waits until roaming is ready, and then the roaming preparation is performed on the target modem. Accurately identify the completion point and use this to perform stable roaming.

In detail, a process of roaming from WCDMA to CDMA will be described. First, if it is determined that roaming is required according to a predetermined condition, the WCDMA modem 320 performs roaming initialization to start roaming in step 600. Here, the terminal determines that roaming is necessary when a signal for roaming in the WCDMA weak field region is transmitted from the system or when the strength of a signal level measured by itself is weak.

When the roaming starts as described above, the WCDMA modem 320 transmits a request to the controller 340 to power on the CDMA modem in step 605. At this time, the request from the WCDMA modem 320 is transmitted to the controller 340 through a task for the controller interface inside the WCDMA modem 320. In response to the request, the controller 340 transmits a command to power on the CDMA module to the CDMA modem 310 in step 610. Accordingly, the CDMA modem 310 is powered on, and the roaming preparation is completed by entering the standby state after registering with the system before completing the roaming preparation. Therefore, it is determined whether the CDMA modem 310 is switched to the standby state after the power is turned on, as in step 615.

In the standby state, the CDMA modem 310 transmits a packet message indicating the state of the CDMA modem to the WCDMA modem 320 through the communication path 350 in step 620. This notification message is delivered with the INF message HM_SIO_INTERCHIP_FROM_1X_TO_W_INF_CHIP_ON to indicate that the roaming is ready. In this way, when the preparation for roaming is completed in the target modem, the modem that is operating immediately is notified, and the time required for roaming can be minimized by estimating time vaguely until roaming is prepared, thereby minimizing the waiting time.

The WCDMA modem 320 then transmits an ACK message to the CDMA modem 310 indicating that it has confirmed this in step 625. For example, an ACK message of HM_SIO_INTERCHIP_FROM_W_TO_1X_ACK_CHIP_ON is delivered. At the same time, the WCDMA modem 320 also informs the controller 340 that the CDMA modem 310 is ready to roam. In operation 630, the WCDMA modem 320 recognizes that the CDMA modem 310 is ready to roam through the INF message. In this state, the WCDMA modem 320 requests the controller 340 to turn off the power so that the terminal mode can be switched from the WCDMA mode to the CDMA mode. After receiving the power-off request from the WCDMA modem 320, the controller 340 disconnects the switch from the WCDMA modem 320 in step 640, and then switches the connection with the CDMA modem 310 to be roamed in step 645. Set. As such, the controller 340 connects the switch 330 to the newly-powered modem 310, terminates the operation of the WCDMA modem 320, and then turns off the power in step 650. According to the present invention, by grasping the state of the roaming target modem and minimizing the time required for roaming, the CDMA modem 310 can perform a normal operation at the same time as it is connected through the control unit 340 and the switch 330. do.

In the above description, the process of roaming from WCDMA to CDMA has been described. However, the process of roaming from CDMA to WCDMA is similarly performed by applying the roaming process as described above.

As described above, according to the present invention, a dual mode terminal supporting both CDMA and WCDMA can accurately grasp the state of a target modem to roam in a roaming process between two modes through a communication path directly connecting each modem. have. In addition, the time required for roaming can be minimized by eliminating the need to use a timer that counts the estimated time until roaming is ready. have.

Claims (16)

A dual mode terminal performing efficient roaming between a first communication network and a second communication network, A first modem for processing signals transmitted and received from the first communication network; A second modem for transmitting and receiving a packet through a communication path connected to the first modem and processing signals transmitted and received from a second communication network; If it is determined that roaming is possible at the location where communication is possible with the first modem, and it is determined to move to an area where communication is possible with the second modem, the power of the second modem is turned on, and the second modem is ready to roam. And a control unit for detecting whether the first modem is connected to the second modem to perform a mode according to the connected second modem. The method of claim 1, wherein the control unit And powering off the first modem after releasing the switch connected to the first modem. The method of claim 1, wherein the second modem When the power is turned on, after registering with the system, the terminal enters the standby state and delivers a packet indicating that it is ready to roam through the communication path to the first modem. The method of claim 3, wherein the first modem And notifying a control unit connected to the switch that a packet indicating that preparation for roaming is completed from the second modem is transmitted, and transmitting a response packet according to the packet transmission to the second modem. The method of claim 3, wherein the packet is And a header indicating a type of a packet to be transmitted and received, a length indicating a size of actual data, and data representing data according to the packet. The method of claim 1, And the first communication network and the second communication network are networks corresponding to CDMA networks and WCDMA networks, respectively. The method of claim 1, And the first communication network and the second communication network are networks corresponding to WCDMA networks and CDMA networks, respectively. The method of claim 1, wherein the control unit And receiving the signal for roaming in the weak field of the second communication network from the system to determine whether the roaming is performed. The method of claim 1, wherein the control unit And determining whether to roam according to the strength of the received signal measured from the first modem. The method of claim 1, wherein each of the first and second modems And a task for performing an interface by controlling a transmission / reception through the control unit and a switch, and a task for performing an interface by controlling transmission / reception through a communication path connecting the modem. terminal. The method of claim 10, And a task for performing an interface with the controller and a task for performing an interface between each modem operate independently of each other. An efficient roaming method in a dual mode terminal having a first modem and a second modem capable of communicating in different mobile communication methods, Determining whether to roam according to a signal received from the first communication network at a position where communication is possible to the first modem; When roaming is started, the step of powering on the second modem, Determining whether the second modem is ready to roam through a communication path connecting the modems; And when the determination result is ready to roam, turning off the power of the first modem and performing communication through the second modem. The method of claim 12, The first communication network and the second communication network is a network corresponding to a CDMA network and a WCDMA network, respectively, wherein the first modem and the second modem is a modem for processing signals transmitted and received through the CDMA network and WCDMA network, respectively How to. The method of claim 12, The first communication network and the second communication network are networks corresponding to the WCDMA network and the CDMA network, respectively, wherein the first modem and the second modem is a modem for processing signals transmitted and received through the WCDMA network and CDMA network, respectively; How to. The method of claim 12, wherein the determining of whether to roam Receiving a signal for roaming from a system of the first communication network to determine whether to roam. The method of claim 12, wherein the determining of whether to roam And determining whether to roam according to the strength of the received signal measured through the first modem.

Images