KR20010094376A - The software handshake method in the wll terminal - Google Patents

Abstract

PURPOSE: A method is provided to perform a software handshake between a PC and a WLL(wireless local loop) terminal in a WLL system. CONSTITUTION: It is judged whether a file to be transmitted is a previously set file(S30). When the file to be transmitted is a previously set file, a file name is transmitted to a receiver(S32). An acknowledge signal is waited for the receiver(S34). A size of a file to be transmitted is calculated(S36). A previous set information is transmitted to the receiver(S38) and an acknowledge signal is waited for the receiver(S30-S40). A real data is transmitted to the receiver(S42). It is judged whether all files are transmitted(S44). When all the files are not transmitted, the routine is repeated.

Description

Software Handshake Method for WPU Terminals. {THE SOFTWARE HANDSHAKE METHOD IN THE WLL TERMINAL}

The present invention relates to a handshake method, and more particularly, to a software handshake method between a PC and a WLL terminal in a WLL system.

In general, handshaking is responsible for preventing errors that may occur during data transmission by receiving a predetermined signal while a connection is established between two transmission apparatuses. This handshaking is done by serial communication such as RS-232C.

In the WLL system, a hardware handshake is performed between the WLL terminals or between the WLL terminal and the data server to prevent overrun errors due to differences in data rates.

1 is a block diagram showing a schematic configuration of a general WLL system, in which a WLL terminal 12 is connected to a personal computer 10 by wire, and the WLL terminal 12 and the mobile communication system 100 are connected wirelessly. It is.

The mobile communication system 100 includes a base station 14 performing a radio call relay function in one cell, which roughly defines a predetermined range, a control station 16 controlling a plurality of base stations 14, and the control. And an exchange station 18 for exchanging a call transmitted from the station 16, and an interworking function (IWF) 20 connected to the Internet.

In the WLL system having the above-described configuration, the personal computer 10 and the WLL terminal 12 are connected to serial ports, and serial data transmission and reception are performed, although serial communication may be performed without a handshake. Hardware handoffs are typically made to reduce errors.

For handoff using the serial port, as shown in FIG. 2, the serial port (A) (B) of the transmitting terminal and the receiving terminal should be connected to each other.

The connection type of the serial port is that the transmit (TX) port and the receive (RX) port are alternately connected, that is, the transmit (TX) port is connected to the receive (RX) port, and the receive (RX) port is connected to the transmit (TX) port. Connect the ground (G) to each other.

In order to transmit / receive serial data without handshake, only the transmit / receive port and ground need to be connected to each other. However, in order to perform hardware handoff, the CTS port should be connected to the other RTS port and the RTS port should be connected to the other CTS port.

Actual hardware handoff is performed by a handoff circuit provided in each terminal.

The conventional hardware handshake method as described above has the following disadvantages.

First, since different types of terminals are developed and installed one after another due to the rapid development and change of information and communication technology, the hardware handshake method requiring the same hardware has a disadvantage that the range is increasingly limited.

Second, in order to change or upgrade the system to which the hardware handshake is applied, the hardware circuit must be changed, which is not only economical but also inefficient.

Third, there is a problem in that overrun occurs during data transmission when diagnostic monitoring or a hardware handshake method for checking a communication terminal cannot be used.

1 is a flow chart showing the flow of the file transfer mode by the software handshake of the present invention.

Figure 2 is a flow chart illustrating the flow of the standby mode by the software handshake of the present invention.

Figure 3 is a flow chart showing the flow of the file receiving mode by the software handshake of the present invention.

<Explanation of symbols for main parts of the drawings>

10: PC 12: WLL terminal

14 base station 16 control station

18: switching center 20: data matching device

An aspect of the present invention is to provide a handshaking method using a serial port between two communication devices of a WLL system, comprising: a setting step of transmitting the predetermined information to a receiving side and waiting for an acknowledgment signal; A data transmission step of transmitting actual data to a receiving side after the setting step; It is to provide a software handshake method of a WLL terminal including a transmission confirmation step of determining whether or not the data transmission step is terminated.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in detail, to be divided into a transmission step and a reception step to be described.

3 is a flowchart illustrating a process of data transmission using a software handshake of a WLL terminal according to the present invention.

First, a file verification step (S30) of determining whether a file to be transmitted is a predefined file or not, if not a defined file, escapes a loop, and if a defined file transmits a file name to a receiving terminal. The file transfer step (S32) is performed.

Here, the file verification step is performed by the main CPU built in each terminal.

After the file transfer step S32, a confirmation signal detection step S34 for detecting whether a confirmation signal is received from a receiving terminal while waiting for a predetermined time is performed, and a file size calculation step S36 for calculating a size of a file to be transmitted. ).

Subsequently, a file size transmission step (S38) of transmitting the file size calculated in the file size calculation step (S36) to a receiving terminal is performed, and then a confirmation signal detection step of waiting for a confirmation signal from the receiving side (S40). ).

After the confirmation signal detection step S40, the data transmission step S42 for transmitting the file data to be sent is performed, and then a transmission completion confirmation step S44 is performed to determine whether the file is at the end. If the file is not at the end, that is, if the file transfer is not completed, the process branches to the file size transfer step S38.

Meanwhile, the file name transmission step 32 will be described in more detail.

4 is a flowchart showing the flow of the file name transmission step of FIG. 3, after the specific character transmission step S32a for transmitting a specific character to the receiving side, whether a corresponding character corresponding to the specific character has been received from the receiving side. A corresponding character acknowledgment step (S32b) of determining whether or not is performed.

If the corresponding character is not received in the corresponding character receiving confirmation step 32b, if a corresponding character corresponding to the specific character is not received, an error processing step (S32c) of processing an error is performed, and if the corresponding character is received, the corresponding file name. Proceed to the file name transfer step (S32d) for transmitting.

After the file name transmission step (S32d), it is determined whether or not the receiving end has received all of the file names, that is, whether or not the current data is the end of the file name while receiving the file name. Perform.

5 is a flowchart illustrating a data reception process using a software handshake of a WLL terminal according to the present invention.

Proceed with the character receiving confirmation step (S50) to confirm whether the specific character transmitted from the transmitting side is received at the receiving side, if the specific character is received, proceeds to the confirmation signal transmission step (S52) to receive the specific character safely. Notify the sender of the message.

After the confirmation signal transmission step (S52), the file name reception step (S54) is carried out to receive the file name transmitted from the sender, and then perform the file length reception step (S56) to determine the file length transmitted from the sender. Receive.

The receiving side receiving the file name and the file length proceeds to the confirmation signal transmission step S58 to notify the transmitting side that it has been safely received, and proceeds to the serial data receiving step S60 to receive the serial data sent from the transmitting side.

Unlike the hardware handshaking method described above, the handshaking method can be applied to all files, can be applied to all types of computers, and can be applied between communication devices having different speeds.

For reference, the UART of the WLL terminal consists of a 64 byte transmission FIFO and a transmission control module. The transmit FIFO receives parallel data from the microprocessor. The transmission control module reads data from the transmission FIFO and adds a start bit, an arbitrary parity bit, and a stop bit in series. The transmit FIFO receives a character from the microprocessor.

When the handshake method of the present invention is applied to the UART of such a WLL terminal, an error rate in data communication is reduced by receiving an acknowledgment signal for one information regardless of the speed of the WLL terminal.

According to a preferred embodiment of the present embodiment disclosed as described above has the following advantages.

First, there is an advantage that the status monitoring of the communication device can be performed without error during data communication or file transfer of the WLL terminal.

Second, there is an advantage in that serial communication can be performed when hardware handshaking is not possible.

Claims (3)

In a handshaking method using a serial port between two communication devices of a WLL system, A setting step of transmitting the predetermined information to a receiving side and waiting for an acknowledgment signal (ACKNOWLEDGE SIGNAL); A data transmission step of transmitting actual data to a receiving side after the setting step; And a transmission confirmation step of determining whether or not to end the data transmission step. The method of claim 1, The predetermined information is a file name, a file size, and a software handshake of a WLL terminal, characterized by waiting for an acknowledgment signal from the receiving side after transmission for each information. The method of claim 2, The process of transmitting the file name, Transmitting a predetermined specific character to a receiving side; Waiting for a response character for the specific character from a receiver; Transmitting the filename to the receiving side; And confirming whether or not the transmission of the file name is completed.