KR100474013B1 - Data Transmitting Method Using Multi-wireless Apparatus - Google Patents

Abstract

The present invention relates to a data transmission method using a multi-wireless device that is suitable for efficiently transmitting large data while maintaining connection reliability between transmitting and receiving sides. The data transmission method using the multi-wireless device may include a first step of dividing an original file to be transmitted into data blocks having an optimal size according to a bandwidth of a transmitting wireless device, and identifying the data blocks in each of the data blocks. A second step of attaching each identifier, a third step of assigning a watermark to the data block to be transmitted among the data blocks to which the identifier is attached, and the device control processes of the transmitting side attempting to connect to the wireless network. A fourth step, and a fifth step of transmitting the data block to the receiving side by using each wireless device by reading the block identifier of the data block to which the watermark is given by the device control process which has successfully connected the call. Receiving process receives the transmitted data blocks and translates them into the original file The summation consists of a sixth step. Therefore, in transmitting large data in a wireless environment, it is possible to efficiently transmit with optimized connection reliability.

Description

Data Transmitting Method Using Multi-wireless Apparatus}

The present invention relates to a large-capacity data transmission using a multi-wireless device, and more particularly, to a data transmission method using a multi-wireless device suitable for efficiently transmitting a large-capacity data in a connection maintenance state.

In general, data transmission includes a telephone line (PSTN), a communication network using a cable TV transmission network, a communication line such as ISDN, xDSL, etc., and recently, data communication is performed using a mobile phone (Terminal) while moving. Sometimes.

The principle of data communication using a wired communication network is connected to a destination modem or a data server via a wired communication network via an exchange via a modem installed in a personal PC, thereby performing data communication.

In this case, the maximum data transfer rate is about 500kbps, but in fact, about 300kbps is provided for xDSL lines, and up to 56kbps for PSTN networks.

If a dedicated line is installed, speeds of 56 / 64kbps, 128kbps, 256kbps, 512kbps, 1,024kbps, 2,048kbps, and 45Mbps are provided depending on the grade of the dedicated line.

In the case of individuals, data communication is mainly performed using xDSL or cable TV data network.

In addition, as a method of data communication while moving, data communication may be performed after a mobile terminal and a PC such as a notebook computer are connected to each other through a wireless repeater.

In the case of using the wireless Internet, it takes about 13.3 minutes or more to transmit a data file of 1MB size when data is currently transmitted at a speed of 10kbps.

This speed or time is a problem for multimedia transmission such as moving pictures.

For example, in the case of VCD (Video CD) quality, one 600MB CD stores 60 minutes of video data. If you transfer 5 minutes of VCD video using a 10kbps transmission rate, 50MB of data is required. Because it needs to be transferred, a transfer time of about 665 minutes is required.

Recently, with the development of wireless communication technology, the use of mobile terminals (mobile phones) is becoming more common and rapidly increasing.

As wired networks evolve into general asynchronous transmission (ATM) broadband integrated information networks (B-ISDN) via general telephone networks (PSTN) and integrated information communications networks (ISDN), wireless mobile networks also use digital cellular networks (DCNs), voice-level services. Network and Personal Communication Service (PCS) are evolving into next generation mobile communication (IMT-2000) network that can support multimedia such as high speed data, packet, and video.

Such mobile terminals were initially used only for voice communication, but recently, they are also used for data communication. Recently, mobile communication service providers provide hundreds of contents such as news, banking, and electronic commerce through wireless Internet cellular phones.

Wireless Internet refers to the environment and technology that allows users to receive Internet services through a wireless network while moving. When using the wireless Internet, users can access the Internet anytime, anywhere through mobile communication terminals such as mobile phones and PDAs. In performing information retrieval and e-commerce, time and space constraints can be overcome.

With the advent of the wireless Internet, the development of high-speed communication technology through the introduction of IMT-2000, when multimedia services are provided in earnest, digital audio and video made in the form of MP3, RM, ASF files can be used when and where. You will enjoy it suddenly.

With the development of wireless Internet technology, large data transmission such as multimedia file or program file is expected to be more frequent from mobile communication system to mobile terminal. In particular, a problem of increase in call charges due to a decrease in transmission speed is expected for a mobile terminal user. If a channel environment is not good, a problem of disconnection during data transmission may occur.

Disclosure of Invention An object of the present invention is to solve the above-mentioned problems of the prior art, and to divide and transmit a large amount of data to an optimal size, thereby enabling multi-radio to efficiently transmit large amounts of data while maintaining reliability of channel access. It is to provide a data transmission method using a device.

A feature of the present invention for achieving this object is a first step of dividing an original file to be transmitted into data blocks of an optimal size according to a bandwidth of a transmitting wireless device, and identifying the data blocks in each of the data blocks. A second step of attaching a plurality of identifiers to each other; a third step of assigning a watermark to a data block to be transmitted among the data blocks to which the identifier is attached; and device control processes of the transmitting side attempt to connect to a wireless network. A fourth step of transmitting the data block to the receiving side by using each wireless device by reading a block identifier of the data block to which the watermark is assigned by the device control process that has successfully connected the call; A receiving process of receiving the transmitted data blocks and merging them into the original file It consists of six steps:

Preferably, the device control process that fails to transmit the data block attempts to reconnect the call, displays an unsent flag for the data block that failed to transmit, and writes a watermark for the retransmission once for the data block that failed to transmit. Turn on the retry state variable for further application.

Preferably, when the watermark is located in the last data block of the data block, determining whether there is a data block with the retry variable on; and if there is no data block with the retry variable on, the main process transmits the transmission. Sending an end signal to a server, and if there is a data block with the retry variable on, placing the watermark in the unsent data block and turning off the retry variable; The device control process attempting to retransmit.

Preferably, in the first step, an operator who transmits the data according to the state of the wireless network according to the bandwidth of the transmitting wireless device and the performance of the wireless device stores the data set according to field test or experiment. After construction, operate it.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, a data transmission method using the multi-radio device of the present invention will be described with reference to the accompanying drawings.

The present invention provides a method for efficiently splitting and merging data to be transmitted to provide a method for transmitting and maintaining a large capacity of data based on a multi-wireless device, and a connection maintenance algorithm for securing connection reliability. algorithm) will be described.

Herein, the multi-radio device refers to all radio frequency (RF) communication devices of which bandwidth is limited.

Examples of multi-wireless devices include 802.11 (802.11, 802, 11a), which is a collection of standards for wireless modems and wireless LANs such as code-division multiple access (CDMA), global system for mobile communication (GSM), and general packet radio services (GPRS). , Wireless LAN card such as 802.11b, 802.11g), low frequency below 300MHz and high frequency above 300MHz, and RF module such as microwave module over GHz.

1 is a view for explaining a data transmission method using a multi-wireless device according to the present invention, Figure 2 is a view for explaining the optimum transmission efficiency per hour according to the present invention.

First, the connection maintenance algorithm of the present invention for securing the reliability of the connection will be described.

In the present invention, after transmitting data to be transmitted from the transmitting side by dividing the block size optimized for the bandwidth of the corresponding wireless device, each block is indexed and transmitted. It uses the Split & Merge method, which merges each block according to the index.

At this time, the contents of the algorithm are based on the control of the main process after creating an independent subprocess on the computer called a thread (number of multi-wireless devices + 1 main process). When the connection of each wireless device is disconnected, it informs the main process of its situation and the communication entity (for example, base station) so that it can transmit data again. Attempt to connect to a call.

In the meantime, the main process requests a retransmission of block data that fails to transmit data to a subprocess (or child process) that can afford it. It is possible to secure the connection maintenance and reliability.

First, as the sender executes the transmission program, the main process starts, and the main process splits the original file 10 to be transmitted into a plurality of data fragment files having a set block size and splits the data. After forming the blocks 20, a block identifier ID is assigned to each divided data block 20.

The data block 20 to which the block identifier is assigned is loaded into the memory. At this time, all of the first data blocks 20 are in a ready state. In other words, as is generally known, a process is defined as a running program and is often handled in terms of software. Tasks to be processed are loaded from disk into memory and then processed by the CPU. A set of worklists is a process.

A water mark is added to the data block to be transmitted among the divided data blocks 20.

That is, a watermark is attached to the data block 20 to be transmitted as a pointer to how far transmission is currently completed in the divided transmission and where to be retransmitted in the next transmission. This watermark is a pointer that indicates where to retransmit at the next transmission. Therefore, the watermark indicates the block ID information to be transmitted next time maintained by the main process in the transmission stage. It is logical data held. That is, in general, since wireless communication has a much higher connection and transmission failure rate than wired communication, an identifier is attached to the data block 20 in a fragment state in order to ensure reliability of data transmission and reception.

When an identifier (ID) is attached to each data block 20, the plurality of device control processes 40 attempt to connect to the wireless network, respectively, and the device control process 40, which has successfully connected the call, has a water mark (Water Mark: The data block 20 is transmitted by reading the block identifier ID of the data block 20 to which the WM is assigned. At this time, the watermark is increased. The data block being transmitted is kept busy.

The device control process 40 here controls the wireless device 30 as an independently executable thread. At this time, the number of threads and the number of the wireless devices 30 are mapped 1: 1. That is, if ten wireless devices 30 are present at the transmit end, there are ten device control processes 40 as well. The device control process 40 directly drives each wireless device 30, attempts to connect to a communication host, transmits data according to a communication protocol, and maintains a main process 90 when an abnormal situation occurs. This module is in charge of actual device control and data transmission such as notifying the status to the next and receiving the next instruction.

At this time, the device control process 40 that fails to connect the call attempts to reconnect.

In addition, even if the call connection is successful, the device control process 40 that fails to transmit data also attempts to reconnect and marks the untransmitted flag for the corresponding data block 20 that failed to transmit. That is, a flag of a READY state is displayed in the untransmitted data block 20. Then turn on the RETRY state variable to apply the watermark (WM) once more.

The device control process 40, which has successfully transmitted the data, transmits a SEND OK message to the main process 90, whereby the main process 90 transmits the untransmitted untransmitted data indicated by the watermark WM. Instruct the device control process 40 to send the block 20.

In this way, the main process 90 controls each thread THREAD.

Finally, when the watermark comes to the last data block (N block) 20, if the retry state is off, the main process 90 sends an end signal to the server, and retrys it. If the state is on, the watermark is placed in the first untransmitted data block 20 and the retry state variable is turned off.

At this time, the receiving process 50 of the called server side records the sequentially transmitted data block 20.

When the termination signal arrives from the client, the destination server merges the data fragment files 60 in memory based on the block ID.

Based on the stored data structure, the original data is transferred to the storage device and all situations are terminated.

The basic concept of the method for calculating the optimal block size for data transmission through the wireless network will be described with reference to FIG. 2. If the size of the data block to be transmitted is large, the probability of disconnection of the call during data transmission and the data transmission fail The probability is high, and the overhead required to recover it is large, resulting in a long transmission time.

In other words, if the call connection is not disconnected during transmission and there is no data connection fail, the efficiency is maximum.

However, if the block size is too small, the data transmission stability and reliability is increased, but the transmission time may be longer because the amount of additional data for the block unit processing increases.

The optimal point may therefore vary depending on the state of the wireless network and the performance of the wireless device.

FIG. 3 is a view for explaining an experiment result of transmission efficiency per hour when eight wireless devices are used in a wireless state of 9.6 Kbps transmission rate in the data transmission method according to the present invention.

In case of transmitting data of 1Mbit (1,000,000bit) by using 8 wireless devices in the wireless state of 9.6Kbps transmission rate, block size is 512bit, 1024bit, 2048bit, 4096bit as shown in Table 1. In case of one experiment, if the transmission file is divided and transmitted in 1024 bit block size, it is 4 minutes in average. In case of transmitting and transmitting the file in 512 bit or 2048 bit block size, it is 5 minutes and 4096 bit in average. In the case of sending a split, it took an average of 8 minutes.

In connection maintenance, the connection retention rate was highest when divided into 512 bits.

Number of experiments / size 512 bit 1024 bit 2048 bit 4096 bit 1 time 5 minutes 4 minutes 10 seconds 5 minutes 12 seconds 8 minutes 10 seconds Episode 2 5 minutes 10 seconds 4 minutes 15 seconds 5 minutes 7 seconds 8 minutes 20 seconds ········· 10th 4 minutes 59 seconds 4 minutes 16 seconds 5 minutes 20 seconds 8 minutes 5 seconds Average 5 minutes 4 minutes 5 minutes 8 minutes

Therefore, the optimal point is appropriately available to the operator after constructing a database of data derived by field tests or experiments according to the state of the wireless network and the performance of the wireless device.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

In the data transmission method using the multi-wireless device of the present invention, in the case of large-capacity file transfer, data is divided and transmitted in an optimal state according to the state of the wireless network and the performance of the wireless device, and merged at the receiving side. To solve the load problem, and to reduce the call charges by optimizing the transmission speed to the mobile terminal user, in particular, even if the channel environment is bad, it is possible to minimize the disconnection during data transmission.

1 is a view for explaining a data transmission method using a multi-wireless device according to the present invention

2 is a view for explaining the basic concept of the optimum transmission efficiency per hour according to the present invention

3 is a view for explaining an experimental result of the transmission efficiency per hour in the case of using eight wireless devices in a wireless state of 9.6Kbps transmission rate of the data transmission method according to the present invention

Claims (4)

After building a field test data or experimental data on the state of the wireless network according to the bandwidth of the transmitting wireless device and the performance of the wireless device into a database, the original file to be transmitted according to the bandwidth of the transmitting wireless device is a data block of an optimal size. Dividing into groups; Attaching an identifier for identifying the data blocks to each of the data blocks, respectively; A third step of assigning a watermark to a data block to be transmitted among the data blocks to which the identifier is attached; A fourth step in which the device control processes at the transmitting side attempt to connect to a wireless network; A fifth step of the device control process succeeding in the call connection reading the block identifier of the data block to which the watermark is assigned and transmitting the data block to a receiving side using each wireless device; And a sixth step in which the receiving process of the receiving side receives the transmitted data blocks and merges them into the original file. 2. The device control process of claim 1, wherein the device control process that failed to transmit the data block attempts to reconnect the call, displays an unsent flag for the data block that failed to transmit, and water for the retransmission for the data block that failed to transmit. A method of data transmission using a multi-wireless device, characterized in that the retry state variable is turned on to apply the mark once more. The method of claim 2, further comprising: determining whether a data block with the retry variable is on when the watermark is located in the last data block of the data block; Transmitting an end signal to the transmitting server, and if there is a data block in which the retry variable is on, placing the watermark in the untransmitted data block and turning off the retry variable; And attempting retransmission by the device control process for a data block. delete