KR100503917B1 - Serial port driver architecture supporting virtual dual serial ports and method for managing these dual serial ports - Google Patents

Abstract

Disclosed are a serial port driver structure supporting virtual dual serial ports and a method of managing these ports using the same. The serial port driver includes a first virtual serial port used for transmitting and receiving an AT command that performs a telephone function and a control function, and an AT command and a PPI for a data communication service. PPP) supports a second virtual serial port for one modem port hardware used for transmitting and receiving packets. While the first virtual serial port is opened in response to a use request of the first application program, and the telephone call service is provided, the second virtual serial port is kept closed so that the data communication service is not provided. While the second virtual serial port is opened in response to a use request of the second application to provide a data communication service, the first virtual serial port driver conveys the fact to the first application so that the telephone call service is not provided.

Description

Serial port driver architecture supporting virtual dual serial ports and method for managing these dual serial ports}

The present invention relates to a method of managing a communication port connected to a modem and a method of implementing a virtual serial port driver.

In general, a communication method connected to a modem is commonly used with Universal Asynchronous Receiver Transmitter (UART) and Universal Serial Bus (USB), and an application program accesses the modem through an operating system serial port driver.

Conventional serial port drivers have a one-to-one correspondence structure, one per physical communication port. That is, there are as many serial port drivers as there are physical ports, and each driver controls only a specific communication port. One serial port driver can be used by multiple applications, but only one application has read / write privileges.

In this architecture, two different applications cannot read / write to a physical communication port at the same time. At any point in time, there is only one application that has a license for the serial port driver, and that serial port driver can also run a corresponding physical communication port. Thus, for example, if a telephone application uses a serial port, the data communication program cannot use that port. In this case, in order to use data communication, the corresponding port must be released from the telephone application.

Figure 1 shows a block diagram of the functional elements using serial ports in a typical dial-up networking architecture in a Windows CE operating system environment. In general, one serial port 130 exists per interface of the physical modem 128, and an application program having a right to read / write the serial port 130 cannot exist at the same time. Application program 1112 performs a telephone function and a control function, and directly transmits and receives an AT command (AT command) to the serial port 130. Application program 2 114 performs a network function and transmits and receives a PPP packet to the serial port 130. In order for application 2 114 to provide a network service, a remote telephone connection must be made by the RAS 122.

In this configuration, application 1 112 and application 2 114 cannot access serial port 130 at the same time. To provide dial-up networking services, if an application is currently 'opening' and using a COM port, no other application can 'open' the COM port. In order for an application to control the modem 128 to provide dial-up networking services, of course, the COM port must be used. Since only one COM port 130 exists per modem 128, the application currently has permission to use it. The program must terminate its use before other applications can control the modem 128 via the COM 130.

As mentioned above, operating systems generally provide data communication services through dial-up networking. In order to use data communication service, a modem port (serial port) must exist below. During data communication, the operating system has full authority to use the modem port. If there is only one modem port, the telephone application must have port permission only at the time when data communication is not used, so there is a limitation in function. In addition, the port should be monitored periodically to check the time when data communication is not used. Therefore, the program structure becomes complicated and the execution speed becomes slow.

In order to solve this problem, the present invention supports two virtual serial ports for one physical modem, and the right of use of these two virtual serial ports is properly changed according to the internal state changed by an external event. The purpose of this paper is to provide a structure of a serial port driver that can be controlled so that the service requested by a telephone application and the service requested by a data communication application can function independently of each other, and a serial port management method therefor. do.

According to an aspect of the present invention for achieving the above object, the first virtual serial port used for the transmission and reception of the AT command to perform a telephone function and a control function, and for the data communication service Supports a second virtual serial port for one modem port hardware used to transmit and receive AT commands and PPP packets, and supports the first virtual serial port in response to a request for using a first program. While the telephone call service is open, the second virtual serial port is kept closed so that the data communication service is not provided, and the second virtual serial port is opened in response to a request for using a second program. While the data communication service is provided, the first virtual serial port driver transmits the fact to the first program. It is provided by a serial port driver, characterized in that to avoid providing telephone call service.

The serial port driver has its own internal state, at least that the second virtual serial port is closed and cannot be used, and the first virtual serial port is open, which is associated with a telephone call. An idle state S2 capable of transmitting and receiving an AT command; A call state (S3) in which the MCP driver has received an I / O control for initiating a telephone call through the open first virtual serial port because the second virtual serial port is closed and cannot be used; And the second virtual serial port is open so that an AT command and a PPP packet may be transmitted and received, but the first virtual serial port may be in an open or closed state and may be open. It is preferable to include a data communication state (S4) that can not be a telephone call through this. The internal state of the serial port driver is transitioned by an external event that calls the interface of the serial port driver.

The state transition of the serial port driver is performed as follows.

First, when the internal state of the serial port driver is the idle state (S2), through the call of the interface function (COM_IOControl) to perform the I / O control of the serial port, the call is started before the first program originating or incoming When the first I / O control code (IOCTL_CALL_START) is transmitted to the driver of the first virtual serial port, the device transitions to the call state (S3).

Second, when the internal state of the serial port driver is the call state (S3), through the call to the interface function (COM_IOControl) that performs I / O control of the serial port, the first program to inform that the telephone call has ended When 2 I / O control code (IOCTL_CALL_STOP) is transferred to the first virtual serial port driver, it transitions to the idle state S2.

Third, when the internal state of the serial port driver is in the idle state S2, when the interface function COM_Open for opening the second virtual serial port is called, the data communication state S4 is started and data communication starts. The first event EV_DATA_START for notifying of the error is delivered to the first program so as to reject the call request of the user.

Fourth, when the interface function COM_Close for closing the second virtual serial port is called in the data communication state S4 in which both the first and second virtual serial ports are open, an internal state of the serial port driver is determined. A transition to the idle state S2 is performed, and a second event EV_DATA_STOP for notifying that the data communication is terminated is transmitted to the first program so that the telephone call request can be accepted.

On the other hand, according to another aspect of the present invention for achieving the above object, the first virtual serial port used for the transmission and reception of the AT command to perform a telephone function and a control function, and for a data communication service In a serial port management method of a serial port driver that supports a second virtual serial port for one modem port hardware, which is used to transmit and receive AT commands and PPP packets,

The second virtual serial port is closed and cannot be used, and the first virtual serial port is open, in an idle state S2 capable of transmitting and receiving an AT command related to a telephone call. The first I / O control code (IOCTL_CALL_START) for notifying the start of a call before the first program makes a call or an incoming call through a call of an interface function (COM_IOControl) that performs I / O control of a serial port. When the driver transmits to the driver of the virtual serial port, the internal state of the serial port driver indicates that the second virtual serial port is closed and cannot be used. AT command) is transitioned to the call state (S3) delivered to the modem; And

When the internal state is the idle state S2, when the interface function COM_Open for opening the second virtual serial port is called, the second virtual serial port is open, thereby enabling an AT command. A first event for transmitting and receiving a PPP packet and the first virtual serial port transitions to a data communication state (S4), which may be in an open or closed state and a telephone call is impossible even in an open state, and also indicates that data communication is started. And transmitting the EV_DATA_START to the first program so as to reject the call request from the user thereafter.

In the serial port management method, when the internal state of the serial port driver is the call state (S3), a call is terminated by the first program through a call to an interface function (COM_IOControl) that performs I / O control of the serial port. When the second I / O control code (IOCTL_CALL_STOP) is transmitted to the first virtual serial port driver, it is preferable to further include the step of transitioning to the idle state (S2).

Further, the serial port management method, when the interface function (COM_Close) for closing the second virtual serial port is called in the data communication state (S4) in which both the first and second virtual serial port is open, the serial port Transitioning the internal state of the driver to the idle state S2, and forwarding a second event (EV_DATA_STOP) for notifying that the data communication is terminated to the first program so that the telephone call request can be accepted. It is preferable.

According to the serial port driver structure and the serial port management method of the present invention as described above, it is configured in the form of a serial port driver is compatible with existing functions. In addition, the modem port driver architecture of the present invention provides two logical virtual serial ports for use in telephony applications and data communication services, for example. By defining several internal states of the serial port driver and transitioning the internal state by external events calling the interface of the serial port driver, the service request of the telephone application can be controlled by appropriately controlling the permissions of these virtual serial ports. Data communication service requests from and other programs can be accepted without conflict.

Hereinafter, with reference to the accompanying drawings will be described the present invention in more detail.

2 is a block diagram of functional elements using a Modem COM Port (MCP) driver according to the present invention employed in place of an existing serial port in a typical dial-up networking architecture in a Windows CE operating system (OS) environment. Indicates. The communication port driver 220 proposed by the present invention is a driver of a modem port 218 that interfaces with a modem (not shown). The communication port driver 220 is implemented as one driver and logically takes a structure supporting two virtual communication ports 222 and 224. In other words, logically, two communication ports are provided for one physical modem. The two virtual communication ports 222 and 224 are implemented in the same structure as the serial port driver so as to appear in the same form as a general serial port on the operating system (OS). Therefore, it includes all serial communication services. In this architecture, the virtual serial port 1 (222) is the Voice Modem COM Port (VMCP), the virtual serial port 2 (224) is the Data Modem COM Port (DMCP), and the modem port driver that supports these two virtual ports. The port driver 220 will be referred to as an MCP (Modem COM Port) driver. This structure is independent of the communication interface with the modem (UART, USB, etc.). The MCP driver 220 controls the 'state' and 'access' of the modem port 218 according to each event occurring in these virtual serial ports 222 and 224.

VMCP 222 and DMCP 224 are themselves serial port drivers (strictly COM ports). However, each COM port does not have an independent existence but shares one resource (physical port). The present invention provides a method for such access control. The VMCP 222 is used for the transmission and reception of AT commands that perform telephony functions and additional control functions related to the telephone (e.g., volume control, antenna reception sensitivity inquiry, etc.). Has port permissions in. The DMCP 224 is used for a data communication modem and is used for transmitting and receiving AT commands and PPP packets, and mainly has a port usage right in an OS. The MCP driver 220 controls the usage rights of the physical modem according to the use state of the serial ports 1 and 2.

The MCP driver 220 may be implemented as, for example, a dynamic library (DLL), and may be implemented in a form in which the VMCP 222 and the DMCP 224 are logically present in the single DLL. In this case, the DLL is actually one and the OS consults one DLL when loading the driver for VMCP 222 and DMCP 224. In other words, since the VMCP 222 and the DMCP 224 appear to be different COM ports that actually exist from an OS perspective, two COM ports are matched to one physical modem port, but the entity has the same program source. It exists as a DLL.

Here, it is necessary to distinguish between a serial port driver and a COM port. Serial port driver is a program that controls communication devices (eg UART, USB, DPRAM) and sends and receives data. The COM port is created when the serial port driver is loaded by the device manager 320 which is a device driver management program and a component of Windows CE. In most cases, one serial port driver is loaded to create one COM port. However, one serial port driver may be loaded several times to create multiple COM ports. In this case, when the serial port driver is loaded, index information for identifying each COM port is transmitted. The serial port driver may have different processing routines according to the index information. The MCP driver 220 eventually exists as a serial port driver, for example, when loaded with index 0, a VMCP (COM1 port) 222 is created, for example when loaded with index 1, a DMCP (COM2 port) 224 is created. Is generated.

The interface of the MCP driver 220 takes a form in which an extended interface is added to an existing serial port driver interface. The serial port driver interface has a correlation called by the device manager 320. Since only the interface of the existing serial port driver has limitations in state management and port access control, the present invention constitutes an extended interface. In the present invention, the newly added extension interface is mentioned in the state transition table description of FIG. 4 to be described below. Events (EV_DATA_START, EV_DATA_STOP). These extension interfaces apply only to VMCP 222 and not to DMCP 224.

Applications 1 and 2 (202, 204) communicate with the modem via modem port hardware 218 via MCP driver 220. Application 1 202 is a telephone application program related to a telephone call, and performs a telephone call function and various control functions related to the telephone call (eg, a call volume adjustment function, an antenna reception sensitivity display function, and the like). In addition, the application program 2 204 performs a network function, and accesses the DMCP 224 through the TCP / IP stack to transmit and receive PPP packets. The RAS 212 may transmit and receive AT commands by making a remote telephone connection to a remote server (not shown) through a telephony API (TAPI) 214 and a unimodem 216. The PPP packet 210 also transmits and receives a PPP packet. Upon successful completion of the remote access and authentication process, the application service 2 (204) performs a network service. Here, RAS 212, TAPI (214), unimodem (216) is a component of the Windows CE operating system of Microsoft Corporation.

As mentioned earlier, there is typically one serial port per physical modem interface. Applications that have permission to read / write to the serial port cannot exist at the same time. That is, in the case where one serial port is configured for one hardware modem port, application 1 202 and application 2 204 cannot access the serial port at the same time. For example, if Application 2 204 is using the serial port and is in use, Application 1 202 cannot open the serial port. Application 1 202 must use the serial port to control the modem, but since Application 2 204 already has permission to use it, it has no choice but to wait for the service to terminate. In order to solve such various limitations, the present invention proposes a structure in which one serial port driver 211 supports two virtual serial ports.

In one embodiment, WinSock 206, an API of one Window CE that enables communication with another machine, is used to communicate between Application 2 204 and the serial port driver 220. Sockets are set up via a WinSock 206 call by the application. Application 2 202 communicates with the transmit and receive buffers allocated by the socket call. The WinSock layer encapsulates outgoing messages into TCP / IP messages via the TCP / IP layer 208. TCP / IP layer 208 encapsulates messages for serial communication via point-to-point protocol (PPP) 210. PPP layer 210 delivers outgoing datagrams to serial port driver 220 for communication on the modem port hardware.

Most driver interfaces, including serial port drivers, have functions such as OPEN, CLOSE, READ, WRITE, IOCONTROL. To use a port in an application or OS (eg RAS), first open the port to get a handle of the port. With this handle, you can call READ or WRITE to send and receive data. At the end of port use, the CLOSE function is called.

Figure 3 shows an example of the configuration of the interface function of the serial port driver in an environment employing Windows CE as an OS, for example. The application calls the relevant API to access the serial port. The device manager 320 of Windows CE makes an I / O request to the corresponding serial port driver. In this case, the device manager 320 calls a related driver interface function. That is, when an application calls an API, the kernel forwards the request to the device manager 320. At this time, the device manager 320 calls the interface function of the relevant driver that matches the API. Table 1 below summarizes the functions of the serial port driver interface used in the device manager 320 of Windows CE and the functions of each function.

TABLE 1

Interface function function COM_Init Function (302) Initializes the serial device and is called when the serial port driver is loaded. COM_Deinit Function (304) Deinitializes the serial port and is called when the serial port driver is unloaded. COM_Open Function (306) Initializes the serial port driver and is called when a new serial device connection is opened. COM_Close function (308) Closes the serial device, called after the application calls the CloseHandle function. COM_Write Function (310) Allows an application to send data (bytes) to the appropriate port for writing. COM_Read Function (312) Allows an application to receive data (characters) from the serial port. COM_IOControl function (314) Performs I / O control functions such as serial port speed and line status control. COM_PowerUp Function (316) Instructs the serial port driver that the platform is resumed from suspend mode. COM_PowerDown Function (318) Instructs the serial port driver that the platform is entering suspend mode.

However, if you open a port to have read / write permission in a specific program, you cannot open the port in another program. In other words, a program opened first to have read / write privileges will have exclusive permissions to the port.

4 is a state transition diagram inside the MCP driver 220 for controlling the access rights of the physical modem. Each state is described in Table 2 below.

TABLE 2

condition Explanation S0 (NULL) Initial state of the MCP driver 220 and before the MCP driver 220 is loaded by the device manager 320. S1 (INIT) The MCP driver 220 has been loaded by the device manager 320 and initialized, and both the VMCP 222 and DMCP 224 are closed. S2 (IDLE) DMCP 224 is closed and cannot be used, and VMCP port 222 is open to send and receive AT commands related to telephone calls. S3 (CALL) The DMCP 224 is closed and cannot be used, and the MCP driver has received I / O control to notify the start of a phone call through the open VMCP port 222. S4 (DATA) DMCP port 224 is open so that it can send and receive AT commands and PPP packets, and VMCP port 222 can be open or closed and can not make phone calls even in the open state.

 The definition of the S4 state in Table 2 assumes a typical modem that supports both data communications and telephony services, but at any given time only one of them.

The state transition of the MCP driver 220 occurs when the serial port driver interface is called. That is, the internal state of the MCP driver 220 is changed by the call of the serial port driver interface, and the VMCP 222 and the DMCP 224 are restricted from accessing the physical port 218 according to each state. Table 3 below is a description of the state transition of the MCP driver 220.

TABLE 3

State transition event Explanation S0-> S1 (401) COM_Init When the driver is loaded in either the VMCP 222 or the DMCP 224, the state transitions to S1. S1-> S0 (402) COM_Deinit Both the VMCP 222 and the DMCP 224 transition to the S0 state when the MCP driver 220 is unloaded. S1-> S2 (403) COM_Open When the COM_Open interface is called to the VMCP port 222 in the S1 state, the state transitions to the S2 state. S2-> S1 (404) COM_Close When the COM_Close interface is called to the VMCP 222 port in the S2 state, the state transitions to the S1 state. S2-> S3 (405) IOCTL_CALL_START In the S2 state, when the IOCTL_CALL_START I / O control code is passed to the VMCP driver through the COM_IOControl interface function call, it transitions to the S3 state. S3-> S2 (406) IOCTL_CALL_STOP In the S3 state, when the IOCTL_CALL_STOP I / O control code is passed to the VMCP driver through the COM_IOControl interface function call, it transitions to the S2 state. S2-> S4 (407) COM_Open When the COM_Open interface function of the DMCP driver is called in S2 state, it transitions to S4 state. At this time, the EV_DATA_START event is transmitted to the application program using the VMCP port 222. S4-> S2 (408) COM_Close If the COM_Close interface function of the DMCP driver is called while the VMCP port 222 is open, the state transitions to the S2 state. At this time, the EV_DATA_STOP event is transmitted to the application program using the VMCP port 222. S1-> S4 (409) COM_Open When the DM_ driver's COM_Open interface is called in S1 state, it transitions to S4 state. S3-> S1 410 COM_Close If the COM_Close interface of the VMCP driver is called in S3 state, the state transitions to S1 state. S4-> S1 (411) COM_Close If the COM_Close interface of the DMCP driver is called while the VMCP port 222 is not used, the state transitions to the S1 state.

The present invention provides an IOCTL_CALL_START extension I / O control for controlling a conventional serial port driver interface to block a data communication service from being started by informing a telephone application to start and end a call to a VMCP 222 port. The MCP driver interface is configured by adding the control, the IOCTL_CALL_STOP 324 control, and the IOCTL_GET_MCP_STATE 326 control, which is an extended I / O control for querying the status of the MCP driver 220. Furthermore, the MCP driver interface of the present invention includes two extended events, EV_DATA_START event and EV_DATA_STOP event, to inform the VMCP port of the use of the DMCP port 224, which is not present in the existing serial port driver interface. It further includes. As a result, the MCP driver interface of the present invention has three I / O control codes and two additional events defined by the present invention in addition to the existing serial port driver interface. More details are given in Table 4 below. For reference, an extension interface is added to the VMCP port 222, which is intended for use in telephony applications and the telephony application can accept such requests, whereas the extension interface to DMCP port 224. This is because the OS does not know this and accepts only predefined events.

TABLE 4

Control Code / Event Explanation IOCTL_CALL_START -. An I / O control code that the phone application passes to the MCP driver to notify the MCP driver first of the call before the phone application makes a call or makes an incoming call, after which the call is actually attempted. . The MCP driver that receives IOCTL_CALL_START changes the status value to S3. After changing the status, the DMCP port is no longer allowed. IOCTL_CALL_STOP I / O control code that the telephony application passes to the MCP driver to inform the MCP driver that the call has ended, after which the DMCP port is allowed to be used. IOCTL_GET_MCP_STATE -. I / O control code that the phone application passes to the MCP driver to inquire the internal status of the MCP driver, and returns S0 ~ S4 if the inquiry is successful. When the application is run for the first time, the status of the MCP driver is unknown, so IOCTL_GET_MCP_STATE is used to check the status, and the application can determine if it is ready to make a call based on the status value inquired. EV_DATA_START This event is delivered by the MCP driver to notify the telephone application that data communication has started. When the telephone application receives the EV_DATA_START event, it is performed to reject the user's call request. EV_DATA_STOP This event is delivered by the MCP driver to notify the telephone application that the data communication has ended. When the telephone application receives the EV_DATA_STOP event, the call becomes available.

Next, FIG. 5 is a flowchart for making a call for a phone call in a phone application. The telephony application first checks the state of the MCP driver 220 by the origination request 502 (504). If the MCP driver 220 is in the current S2 state, that is, only the VMCP 222 port is open and can transmit / receive AT commands, the MCP driver 220 transfers an I / O control called IOCTL_CALL_START to the VMCP port 222 (506). The AT command is then sent to the VMCP port 222 to initiate a call. At step 504, if the MCP driver 220 is not in the S2 state, an alert message is generated 510 and the request is terminated. In order to make a phone call, the VMCP 222 port is open and an AT command can be transmitted / received to the modem port hardware 218, which is an S2 state.

6 is a flowchart for ending a call in a phone application. Telephone application program to check the status of MCP driver 220 by the end of the call request 602 (604). If the MCP driver 220 is in the S3 state, that is, the user is currently making a phone call and the DMCP port 224 is unavailable, the AT command is transmitted to the VMCP port 222 (606), and then IOCTL_CALL_STOP. Pass the I / O control of (608). If the MCP driver 220 is not in the S3 state in step 604, an alarm message is generated 610 and the request is terminated.

As described above, the MCP driver 220 according to the present invention includes not only all the existing serial port driver interfaces, but also several I / O controls (IOCTL_CALL_START, IOCTL_CALL_STOP, IOCTL_GET_MCP_STATE) and events (EV_DATA_START, EV_DATA_STOP). In addition, it extends the existing serial port driver interface. All of these added interfaces relate to telephony applications that use VMCP port 222. The phone application is not a component of the operating system, it is up to the developer to implement it. In contrast, there is no additional expansion interface for the DMCP port 224, and the existing serial port driver interface is used as it is.

Since the data communication follows the order of dial-up networking of the OS as it is, details thereof are outside the scope of the present invention, and thus description thereof will be omitted. The DMCP port 224 is identical to the existing serial port driver interface, while the VMCP port 222 has an additional extension interface, which is an important feature of the present invention. The decisive reason for presenting such a structure is that in most cases, data communication uses the dial-up networking function of the OS and the OS does not control the use of COM ports. If you can't change the OS, the only thing you can do is change the serial port driver and phone application. That is, the DMCP port 224 is inevitably identical to the existing serial port driver interface because the OS uses it, and since the VMCP port 222 is a port used by a telephone application, even if the terminal has an additional extension interface, Since it includes the port driver interface, there is no problem with compatibility.

The present invention can be applied in various forms. When the present invention is applied to a mobile communication terminal in which a wireless communication module (or modem) is embedded, the MCP driver 220 may be configured to operate as a serial port driver that interfaces with the wireless communication module. The present invention can also be applied to a PDA supporting PCMCIA or CF interface. That is, it can be configured to operate as a serial port driver that interfaces with a wireless modem in a PDA device equipped with a wireless modem through a PCMCIA or CF expansion slot. Furthermore, it can be applied to a computer connected to a wireless modem through a UART or USB interface, so that it can operate as a serial port driver that interfaces with the wireless modem.

What has been described above is only a preferred embodiment of the present invention, and those skilled in the art will be variously modified and changed the present invention without departing from the spirit and scope of the present invention described in the claims below. You can. For example, although the present invention has been described using the OS environment of Windows CE as an example, the technical idea of the present invention can be applied to other OS environments. In addition, the case in which the internal state of the serial port driver is defined and managed in five ways is taken as an example. However, those skilled in the art will understand that the idle state S2, the telephone call state S3, and the data communication state are based on the technical concept of the present invention. It may be easy to change the definition of S4), the transitional relationship and the equivalent transformation between each other, or to further define other states while providing the additional state. Furthermore, although the description has been made on the assumption that the principal of the MCP driver 220 is an application program, the MCP driver 220 may be used not only for the application program but for other drivers or modules. Furthermore, although the case where the users of the VMCP port 222 and the DMCP port 224 are the telephone application and the operating system has been described as an example, this is merely an example, and the users of these two ports are widely used in various programs (eg, applications). Program, OS, driver, etc.).

Accordingly, all changes that come within the meaning or range of equivalency of the claims are to be embraced within their scope.

 The structure of the serial port driver of the present invention supports two virtual serial ports for one physical modem, and appropriately controls the usage rights of the two virtual serial ports according to the internal state changed by an external event. As a result, it is possible to manage the service requested by the telephone application program and the service requested by the data communication related application to function independently of each other.

Figure 1 shows a block diagram of the functional elements using serial ports in a typical dial-up networking architecture in a Windows CE operating system environment.

Figure 2 shows a block diagram of the functional elements using a Modem COM Port (MCP) driver according to the invention employed in place of an existing serial port in a typical dial-up networking architecture in a Windows CE operating system environment.

3 illustrates a serial port driver interface used in a device manager.

4 is a state transition diagram inside an MCP driver (Modem COM Port) for controlling access rights of a physical modem.

5 is a flowchart of a call origination in a phone call application.

6 is a flowchart illustrating a call termination in a telephone call application.

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

202: Telephony application 1 204: Data communication application 2

220: serial port driver 222: virtual serial port 1 (VMCP)

224: Virtual Serial Port 2 (DMCP) 218: Modem port hardware

Claims (19)

A first virtual serial port used for transmitting and receiving an AT command that performs a telephone function and a control function, and an AT command and a PPP packet for a data communication service. Supports one modem port hardware for the second virtual serial port used for sending and receiving While the first virtual serial port is opened in response to a request for using the first program, while the telephone call service is provided, the second virtual serial port is kept closed so that the data communication service is not provided. While the second virtual serial port is opened in response to a request for using a second program to provide a data communication service, the first virtual serial port driver transmits the fact to the first program so that a telephone call service is not provided. Serial port driver, characterized in that. 2. The serial port driver of claim 1, wherein the serial port driver is in its own internal state and at least the second virtual serial port is closed and unusable, and the first virtual serial port is open. An idle state S2 capable of transmitting and receiving a call related AT command; A call state (S3) in which the MCP driver has received an I / O control for initiating a telephone call through the open first virtual serial port because the second virtual serial port is closed and cannot be used; And the second virtual serial port is open so that an AT command and a PPP packet may be transmitted and received, but the first virtual serial port may be in an open or closed state and may be open. The phone call through this includes a data communication state (S4), And an internal state of the serial port driver is changed by an external event calling an interface of the serial port driver. 3. The telephone program according to claim 2, wherein the first program is a telephone application related to a telephone call for performing a telephone call function and a control function related to the telephone call, and the second program establishes a remote telephone connection to a remote server. And a program related to performing a network function for transmitting and receiving a Point-to-Point Protocol (PPP) packet. According to claim 2 or 3, wherein the internal state is the idle state (S2), the first program through the call to the interface function (COM_IOControl) that performs the I / O control of the serial port, the first program is the originating or incoming Before the first I / O control code (IOCTL_CALL_START) to inform the start of the call to the driver of the first virtual serial port, the serial port driver, characterized in that the transition to the call state (S3). 4. The first program of claim 2 or 3, wherein the internal program terminates a telephone call through a call of an interface function COM_IOControl that performs I / O control of a serial port in the call state S3. And transferring a second I / O control code (IOCTL_CALL_STOP) to the first virtual serial port driver to inform the user that it is in progress, to transition to the idle state (S2). The method according to claim 2 or 3, wherein the internal state transitions to the data communication state S4 when the interface function COM_Open for opening the second virtual serial port is called in the idle state S2. And transmitting a first event (EV_DATA_START) for notifying that data communication is started to the first program so as to reject a call request from a user thereafter. The interface function (COM_Close) according to any one of claims 2, 3 and 6, for closing the second virtual serial port in the data communication state S4 in which both the first and second virtual serial ports are open. Is called, the internal state transitions to the idle state S2, and a second event (EV_DATA_STOP) for notifying that the data communication is terminated is transmitted to the first program so that the telephone call request can be accepted. Features a serial port driver. The method of claim 2 or 3, In the idle state (S2), through the call of the interface function (COM_IOControl) to perform the I / O control of the serial port, a first for informing the start of the call before the first program originating or incoming When the I / O control code (IOCTL_CALL_START) is transferred to the driver of the first virtual serial port, the call state is transferred to the call state S3. A second I / O control for notifying that the first program terminates a telephone call through a call of an interface function COM_IOControl that performs I / O control of a serial port in the internal state of the call state S3; When the code IOCTL_CALL_STOP is transferred to the first virtual serial port driver, the code transitions to the idle state S2. When the internal state is the idle state S2 and an interface function COM_Open for opening the second virtual serial port is called, the first state transitions to the data communication state S4 and indicates that data communication starts. Deliver event EV_DATA_START to the first program to reject the user's call request thereafter, When the interface function COM_Close for closing the second virtual serial port is called in the data communication state S4 in which both the first and second virtual serial ports are open, the internal state is the idle state S2. And a second event (EV_DATA_STOP) for informing that the data communication is terminated to the first program so as to accept the telephone call request. 9. The serial port driver according to any one of claims 2, 3 and 8, wherein the serial port driver has its own internal state, and further includes an initialization state S1 in which the serial port driver is loaded by a device manager and initialized. Serial port driver, characterized in that. 10. The method of claim 9, wherein the internal state transitions to the idle state (S2) and the second virtual serial port when the interface function (COM_Open) for opening the first virtual serial port is called in the initialization state (S1) When the interface function (COM_Open) to open the call, the serial port driver, characterized in that the transition to the data communication state (S4). The data communication method of claim 9, wherein an interface function (COM_Close) for closing the first virtual serial port is called or the first virtual serial port is closed in the idle state (S2) or the call state (S3). And when the interface function (COM_Close) for closing the second virtual serial port is called in the state (S4), the internal state transitions to the initialization state (S1). The method of claim 2 or 3, The serial port driver has its own internal state, and further includes an initialization state S1 in which the serial port driver is loaded by the device manager and initialized. In the idle state (S2), through the call of the interface function (COM_IOControl) to perform the I / O control of the serial port, a first for informing the start of the call before the first program originating or incoming When the I / O control code (IOCTL_CALL_START) is transferred to the driver of the first virtual serial port, the call state is transferred to the call state S3. A second I / O control for notifying that the first program terminates a telephone call through a call of an interface function COM_IOControl that performs I / O control of a serial port in the internal state of the call state S3; When the code IOCTL_CALL_STOP is transferred to the first virtual serial port driver, the code transitions to the idle state S2. When the internal state is the idle state S2 and an interface function COM_Open for opening the second virtual serial port is called, the first state transitions to the data communication state S4 and indicates that data communication starts. Deliver event EV_DATA_START to the first program to reject the user's call request thereafter, When the interface function COM_Close for closing the second virtual serial port is called in the data communication state S4 in which both the first and second virtual serial ports are open, the internal state is the idle state S2. Transitions to a second event (EV_DATA_STOP) to inform the end of the data communication to the first program to accept the telephone call request, When the internal state is the initialization state (S1), when the interface function (COM_Open) for opening the first virtual serial port is called, the transition to the idle state (S2) and the interface function for opening the second virtual serial port ( COM_Open) is called, transition to the data communication state (S4), In the idle state S2 or the call state S3, the interface function COM_Close is called to close the first virtual serial port or the data communication state S4 in which the first virtual serial port is closed. When the interface function (COM_Close) for closing the second virtual serial port is called, the internal state transitions to the initialization state (S1). A first virtual serial port used for transmitting and receiving an AT command that performs a telephone function and a control function, and an AT command and a PPP packet for a data communication service. In the serial port management method of the serial port driver that supports a second virtual serial port used for transmitting and receiving to one modem port hardware, The second virtual serial port is closed and cannot be used, and the first virtual serial port is open, in an idle state S2 capable of transmitting and receiving an AT command related to a telephone call. The first I / O control code (IOCTL_CALL_START) for notifying the start of a call before the first program makes a call or an incoming call through a call of an interface function (COM_IOControl) that performs I / O control of a serial port. When delivered to the driver of the virtual serial port, the internal state of the serial port driver is used to provide I / O control to notify the start of a telephone call through the first virtual serial port which is not available because the second virtual serial port is closed. Transitioning to the call state S3 in which the MCP driver has been transferred; And When the internal state is the idle state S2, when the interface function COM_Open for opening the second virtual serial port is called, the second virtual serial port is open, thereby enabling an AT command. A first event for transmitting and receiving a PPP packet and the first virtual serial port transitions to a data communication state (S4), which may be in an open or closed state and a telephone call is impossible even in an open state, and also indicates that data communication is started. And transmitting (EV_DATA_START) to the first program so as to reject a call request of a user thereafter. The method of claim 13, A second I / O control for notifying that the first program terminates a telephone call through a call of an interface function COM_IOControl that performs I / O control of a serial port in the internal state of the call state S3; And transmitting a code (IOCTL_CALL_STOP) to the first virtual serial port driver, transitioning to the idle state (S2). The method of claim 13, When the interface function COM_Close for closing the second virtual serial port is called in the data communication state S4 in which both the first and second virtual serial ports are open, the internal state is the idle state S2. And transitioning to a second event (EV_DATA_STOP) for notifying that the data communication has ended so that the call request can be accepted. The method of claim 13, A second I / O control for notifying that the first program terminates a telephone call through a call of an interface function COM_IOControl that performs I / O control of a serial port in the internal state of the call state S3; Transitioning to the idle state S2 when a code IOCTL_CALL_STOP is passed to the first virtual serial port driver; And When the interface function COM_Close for closing the second virtual serial port is called in the data communication state S4 in which both the first and second virtual serial ports are open, the internal state is the idle state S2. And transitioning to a second event (EV_DATA_STOP) for notifying that the data communication has ended so that the call request can be accepted. The method of claim 13, The internal state is the idle state if the interface port (COM_Open) for opening the first virtual serial port is called in the initialization state (S1) that the serial port driver is loaded by the device manager and is initialized When the interface function COM_Open is called to transition to S2 and open the second virtual serial port, the internal state further comprises transitioning to the data communication state S4. Way. The method of claim 17, In the idle state S2 or the call state S3, the interface function COM_Close is called to close the first virtual serial port or the data communication state S4 in which the first virtual serial port is closed. And when the interface function (COM_Close) for closing the second virtual serial port is called, transitioning the internal state to the initialization state (S1). 14. The system of claim 13, wherein the first program is a telephone application related to a telephone call for performing a telephone call function and a control function related to the telephone call, and the second program is configured to make a remote telephone connection to a remote server. And a program related to performing a network function of transmitting and receiving a Point-to-Point Protocol (PPP) packet.