JP2002368811A - Data transmission method, data transfer system, transmitter, and receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data transmission method that can realize fault tolerant data transmission by attaining delivery of data from a transmitter side to a receiver side so as to prevent occurrence of a data loss even for a lapse of time when a fault takes place in a selected path and routing information is rewritten. SOLUTION: This invention provides the data transfer method that uses a network employing packet switching to transfer data from a transmitter to a receiver. The transmitter adds redundant data C to original data A to generate transmission data B, divides the transmission data B into M-sets of division data (b1-bM) and transfers the division data (b1-bM) to a receiver by using N sets of paths. The receiver receives the division data (b1-bM) transferred from the transmitter via N sets of the paths, restores the transmission data B from the division data (b1-bM) and restores the original data A from the transmission data B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a data transfer method,
The present invention relates to a data transfer system, a transmitting device, and a receiving device. In particular, it enables a data transmission from a transmitting side to a receiving side even before a failure occurs on a selected route and routing information is rewritten. The present invention relates to a technology that is effective in preventing data loss and realizing fault-tolerant data transmission.

[0002]

2. Description of the Related Art As shown in FIG.
A method of transferring data over a network using packet switching with IP datagrams such as 0,
One route from the transmission device 10 to the reception device 20 is set by static routing or dynamic routing, and data is delivered using the single route (R1). In the static routing, a route used for data transmission from the transmitting device 10 to the receiving device 20 directly registers routing information by an administrator, and the route once registered is retained unless changed by the administrator. In dynamic routing, RIP (Routing
Information Protocol)
The routing information is exchanged by using a routing protocol such as OSPF (Open Shortest Path First; Open Shortest Path First) and the route is dynamically set. However, as a route used for data transmission from the transmitting device 10 to the receiving device 20, one route having the minimum number of hops is selected in the RIP, and one route having the minimum cost is selected in the OSPF, and the route is generated due to a failure or the like. If there is no change in the information, the same route is always selected.

[0003]

As described above, in the conventional data transmission method, one route on the Internet is used for data delivery, and if a failure occurs on that route, the routing information is not transmitted. Until the data is rewritten, a failure cannot be avoided, and during that time, redundant data transmission using another route was impossible. That is, as shown in FIG. 15A, in the conventional data transmission method, (a1 to a1a) are transmitted from the transmission device 10 to the reception device 20 via a single route (R1) on the Internet.
Although the data of 4) is transferred, as shown in FIG. 15B, before the data of a4 reaches the receiving device 20, R1
When a failure occurs on a single path of
Data cannot be received. For example, HD
It is known that when traffic of about 120 Mbps, such as video data, is transmitted through a single path, packet loss occurs in a router and the video is temporarily interrupted.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide a data transfer method in which a failure occurs on a selected path,
To provide a technology that enables delivery of data from a sender to a receiver even before routing information is rewritten, prevents data loss, and realizes fault-tolerant data transmission. It is in. It is another object of the present invention to provide a data transfer system, a transmission device, and a reception device for realizing the above-described data transfer method. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0005]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows. That is, according to the present invention, when data is transferred from a transmitting side to a receiving side using a network using packet switching, the transmitting side generates redundant data C by adding redundant data C to original data A. Then, the transmission data B is divided into M pieces to generate divided data (b _{1 to} b _M ), and position information for specifying the position of each divided data in the transmission data B is generated. , And the divided data (b _{1 to} b _M ) is transferred to the receiving side using N paths, and the position transferred from the transmitting apparatus through the N paths at the receiving side. The divided data (b _{1 to} b _M ) to which the information is added is received, the transmission data B is restored from the divided data (b _{1 to} b _M ) based on the position information, and the original data A is restored from the transmission data B. It is characterized by doing.

Further, according to the present invention, when data is transferred from a transmitting side to a receiving side using a network using packet switching, the transmitting side converts the original data A into M
In addition to generating divided data (a _{1 to} a _M ) by dividing the data into pieces, generating position information specifying the position of each divided data in the original data A, adding position information to each divided data, (A ₁ -a _M ) is used for L paths,
The data is transferred to the receiving side by broadcast or multicast, and the receiving side receives the divided data (a _{1 to} a _M ) to which the position information is added through N (0 <N ≦ L) paths, and When some or all of the divided data (a _{1 to} a _M ) have been lost in some of the routes, the data is received via a route other than the route in which the data has been lost. Using the divided data (a _{1 to} a _M ), the divided data (a _{1 to} a _M ) is restored based on the position information, and the original data A is restored.

According to the above-mentioned means, when a network using packet switching is used and data is transferred from a transmitting side to a receiving side, a manual or automatic operation is performed between a transmitting apparatus and a receiving apparatus. The set multiple routes are used. Therefore, when a failure occurs in a part of the path, redundant data transfer using another path can be performed. Then, as redundant data, the original data A
By using the duplicate data or the error correction data of the original data A, even if a part of the original data A has not reached the receiving device, the original data A can be restored based on the redundant data. , And fault tolerant data transmission can be realized.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, components having the same functions are denoted by the same reference numerals, and repeated description thereof will be omitted. [First Embodiment] FIG. 1 is a diagram for describing a data transfer method according to a first embodiment of the present invention. In this embodiment, the transmitting apparatus 10 first generates redundant data C for the original data A, and combines the original data A and the redundant data C to generate transmission data B. Next, the transmission data B is divided into sub data (b _{1 to} b _M ), and the transmission data B is transferred from the transmission device 10 to the reception device 20 using N paths. In FIG. 1, the transmission data B is divided into eight sub-data (b1 to b8), and the divided data {b1, b
5}, {b2, b6}, {b3, b7}, {b4, b
8} to 4 (R1, R2, R3, R4)
The case where the transfer is performed to the receiving device 20 using one path is illustrated.

As a method of setting the four routes (R1, R2, R3, R4), as shown in FIG.
In the receiving device 20, different network interface units (NIU; Network Interface Un
it, hereinafter, simply referred to as NIU. ) 51 to connect to another network via another router 52. Alternatively, as shown in FIG. 3, one NIU 51 is connected to a plurality of routes via connections with a plurality of (here, four) Proxy Servers 53 existing on another network. Is also good. Further, the transmission device 1
The configuration shown in FIG. 2 and the configuration shown in FIG. 3, for example, the configuration of 0 is the configuration shown in FIG. 2 (or FIG. 3), and the configuration of the receiving device 20 is the configuration shown in FIG. 3 (or FIG. 2). May be set in combination.

The transmitting apparatus 10 adds position information of each divided data (b1 to b8) in the transmission data B as shown in FIG. 4 to the divided data (b1 to b8), thereby The divided data (b1 to b
8), even if they arrive via different routes in an irregular order, the divided data (b1 to b8) are re-ordered in the receiving device 20 based on the position information shown in FIG. B can be restored. For example, information indicating whether the divided data is a part of the original data A or part of the redundant data C as the payload type, and the number of the divided data of the original data A or the redundant data C as the sequence number And a source ID for uniquely identifying the affiliation of the data. The receiving device 20 restores the original data A from the transmission data B based on the position information as shown in FIG.

[Second Embodiment] FIG. 5 is a diagram for describing a data transfer method according to a second embodiment of the present invention. As shown in FIG. 5, this embodiment is characterized in that x (x ≧ 1) duplicate data A ′ of original data A is used as redundant data C. In FIG. 5, the duplicate data A ′ of one original data A is used as the redundant data C.
Is used, but in this case, the divided data {b1, b5}, {b2, b6}, {b3, b7},
{B4, b8} are the same data. And
In FIG. 5, each divided data (b1 to b8) is transmitted to the receiving device 20 using four paths (R1, R2, R3, R4).
Transfer to In this case, if a trouble occurs on the route of R1, a part of the data (the divided data of b8 in FIG. 6, and the divided data of b1 in FIG. 7) is lost as shown in FIGS. There is a case where it is done. However, in the present embodiment, as shown in FIG. 6, when the divided data (b8) that is a part of the duplicate data A ′ is lost, the divided data (b
Using 4), the original data A can be restored. Further, as shown in FIG. 7, when the divided data (b1) which is a part of the original data A is lost, the divided data (b5) corresponding to the lost original data A in the duplicate data A 'is used. Thus, the original data A can be restored.

[Third Embodiment] FIG. 8 is a diagram for illustrating a data transfer method according to a third embodiment of the present invention. As shown in FIG. 8, the present embodiment is characterized in that error correction data P is used as redundant data C. In FIG. 8, {b1, b4}, {b2, b5},
From the data {b3, b6}, data b7, b8, and b9 are generated by, for example, a parity method. Here, b7 = b1 XOR (exclusive OR circuit) b4, b8 = b2 XORb5, b9 = b3 X
It is represented by OR b6. In FIG. 8, each divided data (b1 to b9) is transferred to three paths (R1, R2, R3).
Is transferred to the receiving device 20. In this case, if a trouble occurs on the route of R1, FIG.
As shown by 0, a case where a part of the data (the divided data of b8 in FIG. 9 and the divided data of b1 in FIG. 10) may be lost is considered.

However, as shown in FIG. 9, when the divided data (b8) which is a part of the error correction data P is lost, the divided data (b
2, b5), the original data A can be restored. Further, as shown in FIG. 10, when the divided data (b1) that is a part of the original data A is lost, the divided data (b4) that is a part of the original data A and a part of the error correction data P The lost divided data (b1) can be reproduced by using the divided data (b7), and the original data A can be restored. In the case of FIG. 10, (b1 = b7
By the XOR b4), the divided data of b1 can be reproduced. Note that, as an error correction method, generation of a Hamming code or the like can be used in addition to the parity method. Further, in the present embodiment, the receiving device 20 can detect and correct errors in the received divided data (b1 to b8) based on the received error correction data P.

[Embodiment 4] In the data transfer method according to Embodiment 4 of the present invention, the transmission apparatus 10 transmits N data (R
When the divided data (b _{1 to} b _M ) is transferred to the receiving device 20 using the first to third RNs, the path Rn (1 ≦ n) used by the m (1 ≦ m ≦ M) -th divided data bm ≦ N), m
Is automatically selected using an equation n = f (m) which is a function of For example, if n = f (m) = m% N (where n represents the remainder when m is divided by N) as a function of m, as shown in FIG. For the data (b1, b5), the route of R1 is automatically selected and transferred to the receiving device 20. Similarly, the divided data (b2, b6) has a route of R2, the divided data (b3, b7) has a route of R3, and the divided data (b4, b).
In 8), the route of R4 is automatically selected.

[Fifth Embodiment] A data transfer method according to a fifth embodiment of the present invention is configured such that the transmitting apparatus 10 transmits N paths (R
1 to RN) to transfer the divided data (b _{1 to} b _M ) to the receiving device 20, the component of the original data A transferred using each path, and the redundant data C (duplication The ratio of the data A ′ or the component of the error correction data P) is not fixed to a specific path so as to be averaged over time.
Divided data (b _{1 to} b _M ) is transferred to each of the paths (R ₁ to RN). For example,
In the case of FIG. 5, one on every route (R1 to R4)
By transferring the components of the redundant data C (the duplicate data A 'or the error correction data P) at a time, the components of the redundant data C are dispersed and transferred to each path on average. Similarly, in FIG. 8, once every three times, redundant data C (duplicate data A ′ or error correction data P) is placed on each path (R1 to R3).
Is transferred, the components of the redundant data C are dispersed and transferred to the respective paths on average.

[Sixth Embodiment] A data transfer method according to a fifth embodiment of the present invention is characterized in that
Is divided into M pieces to generate divided data (a _{1 to} a _M ),
The divided data (a _{1 to} a _M ) are transmitted using L paths,
The transmission to the receiving device 20 is performed by broadcast or multicast. FIG.
FIG. 15 is a diagram for explaining an example of a data transfer method according to the fifth embodiment of the present invention. In the example illustrated in FIG. 11, the divided data (a1 to a4) obtained by dividing the original data A into four are multicast by using four routes (R1 to R4).
The case of transferring to the receiving device 20 is shown. In this case, as shown in FIG. 12, suppose that a1
Is divided on the route of (R2 to R4) by a
Even if the divided data of No. 4 is lost, (R1, R3, R
Via the path of 4), the divided data of a1
Through the path of No. 1, the divided data of a4 is
, The receiving device 20 can restore the original data A. As described above, according to the present embodiment, if the divided data of (a _{1 to} a _M ) has been transferred from at least one of the plurality of paths to receiving apparatus 20, it is used. Thus, the original data A can be restored by the receiving device 20.

[Seventh Embodiment] FIG. 13 is a block diagram showing a schematic configuration of a data transfer system for realizing the data transfer method of each of the above-described embodiments. Hereinafter, a schematic configuration of a data transfer system for realizing the data transfer method of each of the above embodiments will be described. As shown in FIG. 13, the transmission device 10 includes a data storage unit 11, a redundant data creation processing unit 12, a data division processing unit 13, a data output path determination unit 14, and a network interface unit 15. You. The data storage unit 11
It stores original data A, redundant data C (duplicate data A 'or error correction data P), or transmission data B. The redundant data creation processing unit 12 generates redundant data C from the original data A stored in the data storage unit 11,
The processing stored in the data storage unit 11 is executed. For example,
In Embodiment 2 described above, the redundant data creation processing unit 12
Generates x (x ≧ 1) duplicate data A ′ of the original data A and stores it in the data storage unit 11. In the third embodiment, the redundant data creation processing unit 12 The data P is generated and stored in the data storage unit 11.

The data division processing unit 13 includes the data storage unit 1
1, transmission data B is generated from the original data A and the redundant data C (replicated data A ′ or error correction data P), and the transmission data B is divided into M pieces of divided data ( b _{1 to} b _M ). As described above, when the transmission data B is divided, position information that can specify the position of each division data in the transmission data B is generated and added to each division data (b _{1 to} b _M ). The data output path determination unit 14 outputs the divided data (b ₁ to
b _M ) is determined to use which one of the N paths (R1 to RN) to transfer to the receiving device 20.

For example, in the case of Embodiment 4 described above,
The m-th divided data bm is represented by the n = f (m) -th route R
The output path is distributed so as to use n. Also,
In the case of the fifth embodiment, the divided data (b _{1 to} b
_M ) is part of the original data A, part of the redundant data C, or both,
In the data transferred from each path, the ratio of the components of the original data A and the components of the redundant data C is as follows:
The output path is determined so as to be averaged over time. The network interface unit 15 has one or more NIUs, through which it is connected to a network using packet switching. Multiple N
If an IU is present, each NIU is an outlet for the split data (b ₁ -b _M ) to one or more paths. NIU
If only one exists, the NIU becomes a single exit on the transmitting device side to a plurality of paths, and the divided data (b ₁ to b _1
M ) goes out to a plurality of paths via a plurality of proxy servers 53 on different paths.

The receiving device 20 comprises a network interface unit 24, a data storage unit 21, a data synthesis processing unit 23, and a data restoration processing unit 22.
The network interface unit 24 has one or more NIUs, through which it is connected to a network using packet switching. Multiple N
If IU is present, each NIU is made and the inlet of the divided data from one or more paths, _(b 1 ~b _M). N
If IU there is only one, the NIU becomes a single inlet of the receiver side from a plurality of paths through a plurality of proxy servers 53 on another route, divided data from multiple paths (b ₁ ~ b _M ) is input. Data storage unit 21
Via the network 30, the received divided data (b 1 _{~b M),} or stores the restored transmission data B and the original data A.

The data synthesis processing unit 23, from the received divided data _(b 1 ~b _M), based on the position information of the divided data added by the transmission apparatus 10 _(b 1 ~b _M), recover the transmitted data B Execute the processing to be performed. Data restoration processing unit 22
Performs a process of restoring the original data A from the transmission data B stored in the data storage unit 21 and storing the original data A in the data storage unit 21. When the original data A is restored, a part of the original data A in the divided data (b _{1 to} b _M ) is lost. On the basis of the redundant data C (that is, the duplicated data A ′ or the error correction data P), the lost portion is restored, and the original data A is restored. As described above, the invention made by the inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and can be variously changed without departing from the gist of the invention. Of course, it is.

[0022]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows. (1) According to the present invention, it is possible to deliver data from a transmission side to a reception side even before a failure occurs on a selected route and routing information is rewritten,
Data loss can be prevented, and fault-tolerant data transmission can be realized. (2) According to the present invention, when a failure occurs on a part of a route, the problem that the failure is directly affected is improved, and reliability is improved as compared with the conventional data transmission using only one route. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a data transfer method according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a method of setting a plurality of paths in the data transfer method according to the first embodiment of the present invention.

FIG. 3 is a diagram showing another example of a method of setting a plurality of paths in the data transfer method according to the first embodiment of the present invention.

FIG. 4 is a diagram showing an example of position information added to divided data in the data transfer method according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a data transfer method according to a second embodiment of the present invention.

FIG. 6 is a diagram for explaining that original data A can be restored even when a failure occurs on one path in the data transfer method according to the second embodiment of the present invention.

FIG. 7 is a diagram for explaining that the original data A can be restored even if a failure occurs on one path in the data transfer method according to the second embodiment of the present invention.

FIG. 8 is a diagram illustrating a data transfer method according to a third embodiment of the present invention.

FIG. 9 is a diagram for explaining that the original data A can be restored even when a failure occurs on one path in the data transfer method according to the third embodiment of the present invention.

FIG. 10 is a diagram for explaining that original data A can be restored even when a failure occurs on one path in the data transfer method according to the third embodiment of the present invention.

FIG. 11 is a diagram illustrating an example of a data transfer method according to a fifth embodiment of the present invention.

FIG. 12 is a diagram for explaining that the original data A can be restored even if a failure occurs on three paths in the data transfer method according to the fifth embodiment of the present invention.

FIG. 13 is a block diagram illustrating a schematic configuration of a data transfer system for realizing the data transfer method according to each embodiment of the present invention.

FIG. 14 is a diagram for explaining a conventional data transfer method on a network using packet switching based on IP datagrams such as the Internet.

FIG. 15 is a diagram for explaining a problem in a conventional data transmission method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Transmission device, 11, 21 ... Data storage part, 12 ... Redundant data creation processing part, 13 ... Data division processing part, 14 ...
Data output path determination unit, 15, 24 Network interface unit, 20 Receiving device, 22 Data restoration processing unit, 23 Data synthesis processing unit, 30 Internet, 51 Network interface unit (N
IU), 52 ... router, 53 ... proxy server, A ...
Original data, B ... transmission data, a1-a4, b1-b9 ...
Divided data, R1 to R4 ... route.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tetsuro Fujii 2-3-1 Otemachi, Chiyoda-ku, Tokyo F-term in Nippon Telegraph and Telephone Corporation (reference) 5J065 AC02 AD03 AE04 AG04 5K014 AA01 DA06 EA07 FA06 HA05 5K030 GA12 HA08 LA01 LA19 LB06 LD02 LE14

Claims (22)

[Claims] 1. A data transfer method for transferring data from a transmitting device to a receiving device using a network using packet switching, wherein the transmitting device transmits redundant data C to original data A. Generating data B, dividing the transmission data B into M pieces to generate divided data (b _{1 to} b _M ), and generating position information for specifying the position of each divided data in the transmission data B; The position information is added to each of the divided data, and the divided data (b _{1 to} b _M ) is transferred to the receiving device using N paths. Divided data (b) transferred from the transmitting device and
_{1 to} b _M ), the transmission data B is restored from the divided data (b _{1 to} b _M ) based on the position information, and the original data A is restored from the transmission data B. Data transfer method. 2. The transmission device as redundant data C,
The transmission data B is generated by using x (x ≧ 1) pieces of duplicate data A ′ of the original data A, and the receiving device generates the received divided data (b ₁ to b ₁ ).
2. A method according to claim 1, wherein when a part of the original data A in b _M ) is lost, the original data A is restored by using a copy of the lost data in the redundant data C. Data transfer method described in 1. 3. The transmission device as redundant data C:
The transmission data B is generated by using the error correction data P of the original data A, and the receiving device determines an error of the received divided data (b _{1 to} b _M ) based on the received error correction data P. Detect and correct the received divided data (b
_{1 to} b _M ), when part of the original data A in the original data A is lost, the lost data is restored based on the received error correction data P, and the original data A is restored. 2. The data transfer method according to claim 1, wherein: 4. The transmission device according to claim 1, wherein the transmitting unit transmits the divided data (b ₁
The ~b _M), when transferred using N paths (R1 through RN) to the receiving device, m (1 ≦ m ≦ M ) th divided data bm path uses Rn (1 ≦ n ≦ N) is determined using an equation n = f (m) that is a function of m. The data transfer method according to claim 1, wherein: 5. The transmitting apparatus according to claim 1, wherein the ratio of the component of the original data A and the component of the redundant data C transferred using each path is equalized in time so that the number of the components is N. for each path, the divided data (b 1 _{~b M)} data transfer method according to any one of claims 1 to 4, characterized in that to transfer. 6. A data transfer method for transferring data from a transmitting device to a receiving device using a network using packet switching, wherein the transmitting device divides the original data A into M pieces. Data (a _{1 to} a _M ) and the original data A
, Generating position information for specifying the position of each divided data, and adding the position information to each of the divided data to transmit the divided data (a _{1 to} a _M ) using L paths by broadcast or multicast. Forwarded to the receiving device, and the receiving device is connected via N (0 <N ≦ L) paths,
The divided data (a ₁ to
a _M ), and when some or all of the divided data (a _{1 to} a _M ) are lost in some of the N paths, the occurrence of the data loss occurs Divided data (a ₁ to a ₁₎ received via a route other than the route
with a _M), based on the position information, the divided restore the data (a 1 _{~a M),} data transfer method, characterized in that to restore the original data A. 7. A transmitting apparatus and a receiving apparatus, wherein a packet
A data transfer system connected via a network using switching, wherein the transmission device generates transmission data B by adding redundant data C to original data A; divided data is divided into a number _(b 1 ~
b _M ), and divided data generating means for generating position information for specifying the position of each divided data in the transmission data B; and adding the position information to each divided data to generate the divided data (b ₁ B _M ) to the receiving device using N paths, wherein the receiving device transmits the position information transferred from the transmitting device via the N paths. (B)
_{1 to} b _M ); data combining means for restoring the transmission data B from the divided data (b _{1 to} b _M ) based on the position information; A data transfer system, comprising: original data restoring means for restoring original data A. 8. The divided data generating means of the transmitting device,
The transmission data B is generated by using x (x ≧ 1) pieces of duplicate data A ′ of the original data A as the redundant data C, and the original data restoring unit of the receiving device transmits the received divided data (b _{1 to} b _M ), when a part of the original data A in the redundant data C is lost, the original data A is restored by using the duplicate data of the lost data in the redundant data C. Item 8. The data transfer system according to Item 7. 9. The divided data generating means of the transmitting device,
The transmission data B is generated by using the error correction data P of the original data A as the redundant data C, and the original data restoring means of the receiving apparatus performs, based on the received error correction data P, the received divided data (B ₁
To b _M ) are detected and corrected, and when a part of the original data A in the received divided data (b _{1 to} b _M ) is lost, the lost data is received 8. The data transfer system according to claim 7, wherein the original data A is restored by restoring the original error corrected data P. 10. The transfer means of the transmitting device, when transferring the divided data (b _{1 to} b _M ) to the receiving device using N paths (R1 to RN), sets m (1 ≦ m ≦
Route Rn (1 ≦ n) used by the (M) -th divided data bm
≦ N) is determined using an equation n = f (m) that is a function of m. The data transfer system according to claim 7, wherein: 11. The transfer means of the transmission device, wherein a ratio of a component of the original data A and a component of the redundant data C transferred using each path is averaged over time.
For each of the N paths, the divided data (b ₁
~b _M) data transfer system according to any one of claims 7 to 10, characterized in that to transfer. 12. A data transfer system in which a transmitting device and a receiving device are connected via a network using packet switching, wherein the transmitting device divides the original data A into M pieces of divided data, (A _{1 to} a _M ) and the original data A
Divided data generating means for generating position information for specifying the position of each divided data in the above, and adding the position information to each of the divided data, and using the divided data (a _{1 to} a _M ) using L paths. Transfer means for transferring to the receiving device by broadcast or multicast, wherein the receiving device is configured to transmit through N (0 <N ≦ L) paths,
The divided data (a ₁ to
a _M ) receiving means for receiving the divided data (a _{1 to} a _M ) in a part of the N paths when a part or all of the divided data (a _{1 to} a _M ) is lost. Using the divided data (a _{1 to} a _M ) received via a path other than the path in which the loss occurred, the divided data (a _{1 to} a _M ) is restored based on the position information, and the original data A is restored. A data transfer system comprising: 13. A transmitting device used in a data transfer system in which a transmitting device and a receiving device are connected via a network using packet switching, wherein the transmitting device adds redundant data C to original data A and transmits the data. a transmission data generation means for generating data B, the divided data by dividing the transmission data B to M (b ₁ ~
b _M ), a divided data generating means for generating position information for specifying a position of each of the divided data in the transmission data B, and adding the position information to each of the divided data to form the divided data (b _{1 to} b _M ) using N paths to transfer the data to the receiving device. 14. The transmission data B, wherein the divided data generation means generates x (x ≧ 1) duplicate data A ′ of the original data A as redundant data C. Item 14. The transmitting device according to item 13. 15. The divided data generating means uses error correction data P of original data A as redundant data C,
2. The transmission data B is generated.
4. The transmitting device according to 3. 16. The transfer means (b)
_{1 to} b _M ) to the receiving device using N paths (R ₁ to RN), the path Rn (1 ≦ m) used by the m (1 ≦ m ≦ M) -th divided data bm n ≦ N), m
The transmission apparatus according to any one of claims 13 to 15, wherein the transmission apparatus is determined by using a function of n = f (m). 17. The transfer unit according to claim 17, wherein the ratio of the component of the original data A and the component of the redundant data C transferred using each path is averaged over time. The transmitting device according to claim 13, wherein the divided data (b _{1 to} b _M ) is transferred to each path. 18. A transmitting apparatus used in a data transfer system in which a transmitting apparatus and a receiving apparatus are connected via a network using packet switching, wherein the original data A is divided into M pieces and divided. Data (a _{1 to} a _M )
And a divided data generating means for generating position information for specifying the position of each of the divided data in the original data A; and adding the position information to each of the divided data to produce the divided data (a ₁ -a _M )) using L paths and transferring means for transferring to the receiving device by broadcast or multicast. 19. A receiving apparatus for use in a data transfer system in which a transmitting apparatus and a receiving apparatus are connected via a network using packet switching, wherein transmission data B is divided into M divided data. In addition, position information specifying the position of each divided data in the transmission data B before division is added, and the divided data (b _{1 to} b _M ) transferred from the transmitting device via N paths.
Receiving means for receiving the data, data combining means for restoring the transmission data B from the divided data (b _{1 to} b _M ) based on the position information, and data restoration means for restoring the original data A from the transmission data B A receiving device comprising: a data restoring unit. 20. The original data restoring means, when part of the original data A in the divided the received data (b 1 _{~b M)} is lost, divided the received data (b ₁ ~b
_{20. The} original data A is restored by using a copy of the lost data in _M ).
3. The receiving device according to claim 1. 21. The original data restoring means, based on the error correction data P of said received divided data (b 1 _{~b M),} detects an error of the divided the received data (b 1 _{~b M)} When a part of the original data A in the received divided data (b _{1 to} b _M ) is lost, the lost data is replaced with the received divided data (b _{1 to} b _M). 20. The receiving apparatus according to claim 19, wherein the original data A is restored by restoring the error correction data P in the parentheses. 22. A receiving device used in a data transfer system in which a transmitting device and a receiving device are connected via a network using packet switching, wherein N (0 <N ≦ L) paths And the original data A is divided into M divided data transferred from the receiving device by broadcast or multicast through
Receiving means for receiving divided data (a _{1 to} a _M ) to which position information for specifying the position of each divided data in the original data A before the division is added; and in some of the N paths, When a part or all of the divided data (a _{1 to} a _M ) has been lost, the divided data (a _{1 to} a _M ) received via a path other than the path where the loss of the data has occurred. And a source data restoring means for restoring the divided data (a _{1 to} a _M ) based on the position information and restoring the original data A.