JPH11296446A - File transfer method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for most efficiently transferring a file, and a medium for recording a program when plural connections are used to transfer a single file. SOLUTION: The proposed method is designed such that, regarding one file, transmission is performed forward from the leading position of the file to the end by using one connection, for example, a connection 1 and, at the same time, transmission is performed backward from the end of the file to the leading by using another connection, for example, a connection 2. Also, during file transfer such as this, if it is possible to further provide another connection, it is possible to provided more than one connections for transferring file respectively forward and backward from an almost intermediate position of the remaining files.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file transfer method and apparatus for transmitting one file through a plurality of connections, and a recording medium on which a program is recorded. In particular, the present invention is effective in a network such as the Internet or a satellite line in which the transmission efficiency of a connection varies every moment.

[0002]

2. Description of the Related Art FIG. 1 is a schematic diagram of a conventional file transfer method using one connection. As shown in FIG. 1, the file is transmitted in the forward direction from the beginning to the end of the file. This method is used for the existing FTP (File Transfer Protocol) on the Internet.

FIG. 2 is a schematic diagram of a conventional file transfer method using two connections. As shown in FIG. 2, the transmission efficiency can be improved by dividing the file in advance and transmitting each divided file in the forward direction from the beginning to the end using a plurality of connections. When a plurality of connections are used, it is best to complete the file transfer for all connections at the same time for the highest transmission efficiency. Therefore, the file division position must be determined in advance from the file amount so that an even file amount can be allocated to each connection. In FIG. 2, a file is divided at an intermediate position of a file to be transmitted, and each file is transmitted through each connection.

[0004]

However, in a network such as the Internet or a satellite line in which the transmission efficiency of a connection fluctuates momentarily, if there is a difference in the transmission efficiency between two connections, each connection has the same amount. Even in the case of transmitting a file, the file transfer of one connection ends early, and the file transfer of the other connection does not end.
This does not mean that the communication resources of the connection with high transmission efficiency are effectively used.

Accordingly, the present invention provides a method and apparatus for transferring a file most efficiently when a plurality of connections are used to transmit one file, and a recording medium on which a program is recorded. Aim.

[0006]

According to the file transfer method of the present invention, one file is transmitted in the forward direction from the first position to the end, and at the same time, in the reverse direction from the second position to the start. To send to.

According to another embodiment of the method of the present invention, the first location may be at the beginning of the file, the second location may be at the end of the file, , When the position of the file to send in the opposite direction matches,
The file transfer may be terminated.

[0008] According to another embodiment of the method of the present invention, the first position and the second position may be the same position of the file, and further, the forward transmission file position may be at the end of the file. The file transfer may be terminated when the file is reached and the transmission file position in the reverse direction reaches the beginning of the file.

According to another embodiment of the method of the invention, it is also preferred that the transmission is made in the forward direction using the first connection and at the same time in the reverse direction using the second connection. As a result, the file transfer of the two connections is always completed at the same time, so that even if the transmission efficiency of one connection changes, the communication resources of both connections can always be used effectively. In addition, transmission may be performed alternately in the forward direction and in the reverse direction for each predetermined unit using one connection.

Another file transfer method according to the present invention comprises:
A first step of setting a first connection for transmitting one file in the forward direction from the beginning to the end, and a second step of setting a second connection for transmitting the file in the reverse direction from the end to the beginning. And a third step of setting up a third connection for transmitting in the reverse direction from the substantial intermediate position toward the beginning, and simultaneously, in the forward direction from the substantial intermediate position toward the end. And setting a fourth connection to be transmitted.

[0011] A further file transfer method according to the present invention comprises:
A first step of setting a first connection for transmitting one file in the forward direction from the head to the end, and a second step of setting a second connection for transmitting the file in the reverse direction from the tail to the head at the same time A second step, and a third step of setting a third connection for alternately transmitting a predetermined unit from the substantial intermediate position in the backward direction toward the beginning and in the forward direction toward the end. Things.

Further, a file transfer device according to the present invention comprises:
For one file, there are forward transmission means for transmitting in the forward direction from the first position to the end, and reverse transmission means for transmitting in the reverse direction from the second position to the beginning, The two means are configured to be executed simultaneously. The other embodiments of the file transfer method according to the present invention described above can be equally used as other embodiments of the file transfer device.

Further, the recording medium storing the file transfer program according to the present invention transmits the file in the forward direction from the first position to the end, and at the same time, transmits the file from the second position to the beginning in the file. This is to control transmission in the reverse direction. The above-described other embodiment of the file transfer method according to the present invention can be equally used as another embodiment of the file transfer program.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 3 is a schematic diagram of the file transfer method of the present invention using two connections. According to FIG. 3, connection 1 for transmitting one file in the forward direction from the beginning to the end and connection 2 for transmitting the file in the reverse direction from the end to the beginning at the same time are shown. The file transfer ends when the forward transmission file position matches the reverse transmission file position. Therefore, the two connections always end the file transfer at the same time, and the transmission file of one connection with low transmission efficiency can be transmitted by the other connection with high transmission efficiency. Further, there is no need to calculate the file division position in advance.

FIG. 4 is a schematic diagram of the file transfer method of the present invention using three or more connections. According to FIG. 4, first, as shown in FIG. 4A, file transfer is simultaneously started from the forward direction and the reverse direction using the same two connections as in FIG. Next, when the amount of the file to be transferred is large and a connection can be set on the transmission path, a connection for transferring the file in the forward direction and the reverse direction from the approximate intermediate position of the remaining files during the file transfer is set. . However, the overhead caused by setting a connection should also be considered. In FIG. 4B, a connection 3 transmitting in the reverse direction from the intermediate position and a connection 4 transmitting in the forward direction from the intermediate position are newly set. At this time,
If the average speed of the pair of connections 1 and 2 and the average speed of connections 3 and 4 match, connection 1
2 and 3 coincide with the pair of connections 2 and 4 at the same time, which is the most efficient.
In the conventional method according to the above, the file transfer does not end at the same time unless the transmission speeds of all four connections are the same. In such a method, it is possible to increase the number of connections as shown in FIG.

FIG. 5 shows only one connection.
FIG. 2 is a schematic diagram of a file transfer according to the present invention for realizing the file transfer shown in FIG. This can be realized by alternately executing forward transmission and reverse transmission for each predetermined unit of a file using one connection. Therefore, the transmission efficiency in the forward direction and the transmission efficiency in the reverse direction are equal to being half the transmission efficiency of one connection.

FIG. 6 is a schematic diagram of a file transfer method according to the present invention using the file transfer method shown in FIG. 5 and further improving the file transfer shown in FIG. FIG. 6 shows a method of transferring files in a forward direction and a backward direction from an intermediate position using one connection, respectively, as compared with FIG. 4 described above. This can be realized by alternately executing the transmission in the forward direction and the transmission in the reverse direction for each predetermined unit of the file. Therefore, the transmission efficiency in the forward direction and the transmission efficiency in the reverse direction are equal to being half the transmission efficiency of one connection. Each predetermined unit may be a bit or byte unit. The timing for ending the file transfer in this method is when all the transmission file positions of one connection coincide with the transmission file positions of another connection.

In order to transfer files efficiently by the method shown in FIG. 4, it is desired that the connections 3 and 4 in FIG. 4B and the connections 5, 6, 7 and 8 be set simultaneously in FIG. 4B. According to No. 6, there is no need to set such paired connections at the same time. Therefore, when the overhead for setting a large number of connections and the transmission path bandwidth are considered, the method of FIG. 6 may be more efficient than the method of FIG.

In the embodiment described in detail above, various changes, corrections and omissions of the technical idea and scope of the present invention in application to file transfer in a transmission path on which a plurality of connections can be set are made by those skilled in the art. According to this, it can be easily performed. Therefore, the above-described embodiment is merely an example, and is not intended to limit the present invention.
The invention is limited only as defined by the appended claims and equivalents thereof.

[0021]

Therefore, according to the method and apparatus for file transfer of the present invention and the recording medium on which the program is recorded, the two connections always terminate the file transfer at the same time, and the transmission efficiency of one of the two connections is reduced. The transmission file for a low connection can be transmitted on the other connection with high transmission efficiency. Therefore, even if the transmission efficiency of the connection fluctuates, the communication resources of both connections can always be used effectively.

Further, when one file is transferred using a plurality of connections, it is not necessary to calculate the most efficient file dividing position in advance.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a conventional file transfer method using one connection.

FIG. 2 is a schematic diagram of a conventional file transfer method using two connections.

FIG. 3 is a schematic diagram of a file transfer method of the present invention using two connections.

FIG. 4 is a schematic diagram of the file transfer method of the present invention using three or more connections based on FIG.

FIG. 5 is a schematic diagram of a file transfer according to the present invention for realizing the file transfer shown in FIG. 3 with only one connection.

FIG. 6 uses the file transfer method shown in FIG.
FIG. 3 is a schematic diagram of a file transfer method according to the present invention in which the file transfer shown in FIG.

Claims (11)

[Claims] 1. A file transfer method, wherein one file is transmitted in a forward direction from a first position to a tail and simultaneously transmitted in a reverse direction from a second position to a head. 2. The method of claim 1, wherein said first location is at the beginning of said file and said second location is at the end of said file. 3. The method according to claim 2, wherein the file transfer is terminated when the forward transmission file position matches the backward transmission file position. 4. The method according to claim 1, wherein the first position and the second position are:
The method of claim 1, wherein the file is at the same location. 5. The file transfer is terminated when the forward transmission file position reaches the end of the file and the reverse transmission file position reaches the beginning of the file. Item 5. The method according to Item 4. 6. The transmission according to claim 1, wherein the transmission is performed in the forward direction using a first connection, and simultaneously, the transmission is performed in the reverse direction using a second connection. The described method. 7. The method according to claim 1, wherein the transmission is performed alternately in a predetermined unit in the forward direction and the reverse direction using one connection. 8. A first step of setting a first connection for transmitting one file in the forward direction from the beginning to the end, and a second step of simultaneously transmitting the one file in the reverse direction from the end to the beginning. A second step of setting up a connection; and a third step of setting up a third connection to transmit in a reverse direction from the substantial intermediate position toward the beginning, and simultaneously from the substantial intermediate position to the end. Setting a fourth connection to transmit in the forward direction toward the server. 9. A first step of setting a first connection for transmitting one file in the forward direction from the beginning to the end, and a second step of simultaneously transmitting the one file in the reverse direction from the end to the beginning. A second step of setting up a connection, and further setting up a third connection to alternately transmit a predetermined unit from a substantially intermediate position in a backward direction toward the head and in a forward direction toward the end. A file transfer method comprising the steps of: 10. A forward transmission means for transmitting one file in a forward direction from a first position to a tail, and a reverse transmission means for transmitting in a reverse direction from a second position to a head. A file transfer apparatus, wherein the file transfer apparatus is configured to execute both of the means simultaneously. 11. Control is performed such that a file is transmitted in a forward direction from a first position to a tail and simultaneously transmitted in a reverse direction from a second position of the file to a head. A recording medium on which a file transfer program is recorded.