CN1905467A - Network data concast transmission method based on distributed coding storage - Google Patents

Abstract

The invention relates to a distributed code storage-based network data centralized-broadcasting transmitting method, belonging to data transmission technical field, comprising: firstly storing coded data and coding information in plural servers; a user end sends request through network to plural servers; the servers receive data transmission request from the user end and sends confirm and coding information to the user end and packets the coded data and sends data packets to the user end; the user end receives the confirm information and obtains the number of data packets to be received from the coding information and receives the data packets from the servers and decodes them. And its advantages: providing downloading service by powerful servers, assuring relative stability of data service; making distributed data storage and implementing data centralized-broadcasting downloading, raising downloading rate; randomly coding data, saving network bandwidth and improving network survivability.

Description

A kind of network data concast transmission method based on the distributed coding storage

Technical field

The present invention relates to a kind of network data concast transmission method, belong to field of network data transmission technology based on the distributed coding storage.

Background technology

Existing Network Transmission mode comprises the network clean culture, multicast and broadcasting.Clean culture be meant in the network server to a user terminal by setting up the mode of network link transmission data, be data transfer mode the most basic in the network.When a plurality of users need obtain identical data, setting up a plurality of independently unicast transmission links between server and the user, to carry out transfer of data be unusual poor efficiency, because it repeats same data to have sent many times, reduced network bandwidth utilance.Multicast is a server transmits identical data simultaneously to a plurality of user terminals a transmission means, this mode has improved network bandwidth utilance, but because server has only one, therefore for any one multicast user, the speed of its data download can not surpass the speed of download that mode of unicast provides.To be a server transmit the transmission means of data simultaneously to all user terminals in broadcasting, and it is actually a kind of special multicast, and just it does not consider which user is its service object, and giving tacit consent to all users all needs to receive its data.Be similar to multicast, the accessible maximum download rate of the user of each broadcasting also is no more than the speed of download that mode of unicast provides.

Network is broadcast a collection of plays, etc. and is different from above-mentioned three kinds of data transfer modes, and it is meant that a plurality of servers in the network are to the transmission means of a user terminal to transmit data.If a plurality of servers in the network have just constituted the network transmission system of broadcasting a collection of plays, etc. when a plurality of users provide service with this transmission means of broadcasting a collection of plays, etc. respectively.Since adopt the mode broadcast a collection of plays, etc. make the user can be concurrently from a plurality of servers simultaneously download user want data, thereby can improve user's speed of download significantly, shorten download time, thereby reduce because the data transmission fails probability that server or network failure cause.

Utilization is broadcast a collection of plays, etc., and to carry out the exemplary that network data propagates be to adopt the mode of P2P (as use famous softwares such as BitTorrent on user side) to carry out data sharing and download.The user terminal of the data that wait for downloads in the network is downloaded its unexistent partial data concurrently by the reciprocity end around it, thereby obtains complete data apace.Yet the P2P mode has two major defects: 1, ability of user terminal is limited.Under the P2P mode, each reciprocity user terminal is also played the part of the role of server in data download, and its existing data is offered other user terminal downloads.And these user terminals often are made up of PC (PC), its bandwidth and stability can not get guaranteeing, simultaneously, after finishing, user's download exits network probably, thereby reduced the quantity of service terminal in the network, thereby the network mode of broadcasting a collection of plays, etc. of the peer users terminal that places one's entire reliance upon can't provide long-time stable data download service; 2, do not adopt coding.P2P software is divided into data to be transferred the data block of some equal length usually in advance, thereby realizes data sharing reconstruct initial data by transmitting different data blocks between the peer users terminal.Because the terminal that the data download service is provided each other and do not know the other side's the existence and the storage condition of the other side's data, thereby cause the user to receive identical data block from different peer users, thereby the waste network bandwidth, the efficiency of transmission of reduction data.

Summary of the invention

Purpose of the present invention proposes a kind of network based on distributed coding storage server transmission method of broadcasting a collection of plays, etc., data are stored on a plurality of servers through distributed earth after the random coded, provide parallel efficiently download service to user side on the one hand, to improve speed of download effectively, reduce owing to the data failed download probability that some network link lost efficacy even node failure causes by the redundancy encoding data of storing on the server on the other hand, improve the capability to resist destruction of reliability of data transmission and network.

The network data concast transmission method based on the distributed coding storage that the present invention proposes may further comprise the steps:

(1) data and the coded message behind the coding of storage process respectively on a plurality of servers of network;

(2) user side sends the request of transmission data to above-mentioned a plurality of servers by network;

(3) after above-mentioned a plurality of server receives the transmission request of data of user sides, send confirmation and coded message to user side respectively, and with above-mentioned through after the packing data behind the coding by specified circuit by sending to user side;

(4) after user side is received above-mentioned confirmation, from above-mentioned coded message, obtain the packet number N that needs reception;

(5) user side receives from above-mentioned a plurality of servers and adds up to the packet of above-mentioned N, and decodes, if decode successfully, then send the request of termination,, then continue to receive data if decoding is unsuccessful to server, until decoding successfully, and send the request of termination to server.

In the said method, data are carried out Methods for Coding comprise following each step:

(1) data waiting for transmission are divided into a K equal portions original data block, and definite random number generation function and random number generation seed, this random number generation function generates seed according to this random number and produces a random number sequence { r _i, i=1,2 ...;

(2) from above-mentioned random number sequence, extract first random number r ₁, according to cumulative distribution function C _D(x) judge, if satisfy C _D(d-1)＜r≤C _D(d), then with integer d as the coding number of degrees;

(3) from above-mentioned random number sequence, extract second to d+1 random number, round after this d random number multiplied each other with K respectively, obtain the numbering of d original data block, if have mutually the same numbering in above-mentioned d the numbering, then continue to extract and round after follow-up 1 random number and K multiply each other, obtain the numbering of new original data block, and it is replaced above-mentioned identical numbering, repeat this process, until the numbering that obtains a mutually different d original data block;

(4) will carry out XOR with the corresponding original data block of above-mentioned mutually different numbering, obtain a coded data block, and define this coded data block and there is encoding relation in d original data block;

(5) all random numbers that deletion was extracted from above-mentioned random number sequence, finish until coding repeating step (2)～(4).

In the said method, the method that data are decoded comprises following each step:

(1) according to the coded message that receives from each server, obtain the random number generation seed that each server uses, the random number generation function that uses according to coding produces a random number sequence { r identical with coding _i, i=1,2 ...;

(2) from above-mentioned random number sequence, extract first random number r ₁, according to cumulative distribution function C _D(x) judge, if satisfy C _D(d-1)＜r ₁≤ C _D(d), then with integer d as the coding number of degrees;

(3) from above-mentioned random number sequence, extract second to d+1 random number, round after this d random number is multiplied each other with K respectively, obtain the numbering of d original data block;

(4) preceding d+1 random number of deletion from above-mentioned random number sequence, repeating step (2) and (3) are until obtaining the encoding relation that all coded data blocks and all original data blocks exist;

(5) according to above-mentioned encoding relation, the searching coding number of degrees are 1 coded data block, if seek failure, then carry out step (8), as if searching out, then obtain the original data block corresponding with this coded data block;

(6) there is the value of the coded data block of encoding relation to carry out XOR successively with this original data block the value of above-mentioned original data block and all, the value behind the XOR is replaced the original encoding data block value successively, replace the encoding relation of this original data block of back deletion;

(7) repeat above-mentioned steps (5) and (6);

(8) if all original data blocks are resumed, then the report decoding is finished, if do not recover all original data blocks, then the report decoding is not finished.

The network data concast transmission method that the present invention proposes based on the distributed coding storage, its advantage is: adopt powerful server that downloading service is provided, guarantee the relative stability of data, services; Data are carried out distributed storage, realize the download of broadcasting a collection of plays, etc. of data, improve downloading rate; Data are carried out random coded, reduce the user receives identical data when broadcasting a collection of plays, etc. reception probability, save the network bandwidth, and rely on the capability to resist destruction of the redundancy encoding data raising network of distributed storage.

Description of drawings

Fig. 1 is the server workflow block diagram of the inventive method.

Fig. 2 is the user side workflow block diagram of the inventive method.

Fig. 3 is a cataloged procedure flow chart in the inventive method.

Fig. 4 is a decode procedure flow chart in the inventive method.

Fig. 5 is to use the schematic network structure of the inventive method.

Fig. 6 is the service process sequential chart of an application example of the present invention.

Embodiment

The network data concast transmission method that the present invention proposes, at first data and the coded message behind the coding of storage process respectively on a plurality of servers of network based on the distributed coding storage; User side sends the request of transmission data to above-mentioned a plurality of servers by network; After above-mentioned a plurality of server receives the transmission request of data of user sides, send confirmation and coded message to user side respectively, and with above-mentioned through after the packing data behind the coding by specified circuit by sending to user side; After user side is received above-mentioned confirmation, from above-mentioned coded message, obtain the packet number N that needs reception; User side receives from above-mentioned a plurality of servers and adds up to the packet of above-mentioned N, and decodes, if decode successfully, then sends the request of termination to server, if decoding is unsuccessful, then continues to receive data, until decode successfully, and asks to server transmission termination.

Below in conjunction with accompanying drawing, introduce content of the present invention in detail:

The network data concast transmission method based on the distributed coding storage that the present invention proposes, its server workflow block diagram are at first being stored respectively on a plurality of servers of network through data and coded message behind the coding as shown in Figure 1; A plurality of servers send " confirmation Rq " and coded message to user side respectively after receiving " send request of data Rq " of user side, and the coded data packing back that above-mentioned user is needed by specified circuit by sending to each user side; A plurality of servers stop the transmission of above-mentioned coded data after " the stopping sending request Cp " of receiving.If after the coded data that all users are needed all sends, still do not receive " stopping sending request Cq ", stop the transmission of above-mentioned coded data yet.

In the said method, user side workflow block diagram as shown in Figure 2, user side elder generation in the needs data download obtains the packet number N and the coded data block of each server and the encoding relation of original data block that need reception from above-mentioned coded message after above-mentioned " confirmation Rq " and coded message are received in a plurality of servers transmissions " transmission request of data Rq "; User side receives from above-mentioned a plurality of servers and adds up to the coded data packet of above-mentioned N, and decodes, if decode successfully, then send the request of termination,, then continue to receive data if decoding is unsuccessful to server, until decoding successfully, and send the request of termination to server." sending request of data Rq " can send constantly in difference, also can be sent by different communication port at synchronization, and DRP data reception process can be carried out via different port is parallel simultaneously.

In the said method, data are carried out Methods for Coding, its FB(flow block) as shown in Figure 3, data waiting for transmission are divided into a K equal portions original data block, and definite random number generation function and random number generation seed, this random number generation function generates seed according to this random number and produces a random number sequence { r _i, i=1,2 ...; From above-mentioned random number sequence, extract first random number r ₁, according to cumulative distribution function C _D(x) judge.Such as, cumulative distribution can for:

$C_D\left(x\right)=\left\{\begin{array}{c}0,x=0\\ \underset{y=1}{\overset{x}{\mathrm{\Σ}}}D\left(y\right),x=\mathrm{1,2},...,k\end{array}\right.,$

Wherein $R\∈\frac{K}{\ln \left(\frac{K}{\mathrm{\δ}}\right)}\left[\mathrm{0.03,0.1}\right],$ δ∈(0，0.1]

The concrete grammar of judging is: if satisfy C _D(d-1)＜r ₁≤ C _D(d), then with integer d as the coding number of degrees; From above-mentioned random number sequence, extract second to d+1 random number, round after this d random number multiplied each other with K respectively, obtain the numbering of d original data block, if have mutually the same value in above-mentioned d the numbering, then continue to extract and round after follow-up 1 random number and K multiply each other, the numbering that obtains new original data block replaces above-mentioned identical numbering, repeats this process, up to the numbering that obtains a mutually different d original data block; To carry out XOR with the corresponding original data block of above-mentioned numbering, and obtain a coded data block, and there are encoding relation in definition coded data block and d original data block; All random numbers that deletion was extracted from above-mentioned random number sequence repeat said process, until the coded data packet that generates sufficient amount.Above-mentioned enough coded data packet quantity is integer $N_S\≥\frac{N}{S},$ Can ruin requirement adjustment according to the system of broadcasting a collection of plays, etc. anti-, scope is [N _S,+∞).Wherein S is the server number of this coded data of storage, and N is for being not less than Smallest positive integral.

In the said method, to the method that data are decoded, its FB(flow block) as shown in Figure 4, according to the coded message that receives from each server, obtain the random number generation seed that each server uses, the random number generation function that uses according to coding produces a random number sequence identical with coding; From above-mentioned random number sequence, extract first random number r ₁, according to cumulative distribution function C _D(x) judge, if satisfy C _D(d-1)＜r ₁≤ C _D(d), then with integer d as the coding number of degrees; From above-mentioned random number sequence, extract second to d+1 random number, round after this d random number is multiplied each other with K respectively, obtain the numbering of d original data block; D+1 random number before the deletion repeats above-mentioned encoding relation recovery process from above-mentioned random number sequence, until obtaining the encoding relation that all coded data blocks and all original data blocks exist; Obtain beginning behind the encoding relation decoding, seek the coding number of degrees and be 1 coded data block, if seek failure, and all original data blocks are resumed, and then the report decoding is finished, if do not recover all original data blocks, then the report decoding is not finished; If seek successfully, then obtain the original data block corresponding with this coded data block; There is the value of the coded data block of encoding relation to carry out XOR successively with this original data block the value of this original data block and all, the value behind the XOR is replaced the original encoding data block value successively, replace the encoding relation of this original data block of back deletion; Repeat above-mentioned decode procedure.

In the said method, broadcast a collection of plays, etc. transmission system as shown in Figure 5 based on the network data of distributed coding storage.System comprises server, network and user side three parts.Network connects a plurality of servers and a plurality of user, has stored the coding of waiting for the data of user's download above the server at each, and user side then sends the request of transmitting data by network to server, reduces the time of downloading by the parallel data of accepting.Server is replied acknowledge message after the transmission request of receiving user side, and with coded message and coded data by specified circuit by sending to user side.

The service process sequential chart of an application example of said method as shown in Figure 6.Suppose that certain system adopts 6 server S ₁～S ₆Download service to 4 film A, B, C and D is provided.S ₁～S ₃On have 3 different version of code A of film A respectively ₁～A ₃With 3 of film C different version of code C ₁～C ₃, S ₃～S ₆The version of code B that has film B and D respectively ₁～B ₄And D ₁～D ₄

Suppose that certain user side is at moment t ₁The A that need download movies is at moment t ₂The B that need download movies, then this user side is at moment t ₁To server S ₁～S ₃Send and " send request of data Rq _A", server S ₁～S ₃Reply data validation information Rp respectively after receiving request _A1～Rp _A3Coded message separately, and begin to send data DATA _A1～DATA _A3The coded data packet that receives as the user then sends one " stopping sending request Cp " to server S when enough it recovers film A ₁～S ₃, server S ₁～S ₃Just stop sending.

Similarly, at moment t ₂, this user side is to server S ₃～S ₆Send and " send request of data Rq _B", server S ₃～S ₆Reply data validation information Rp respectively after receiving request _B1～Rp _B4Coded message separately, and begin to send data DATA _B1～DATA _B4If server S ₅Transmitting sudden failure during the course, DATA _B3No longer send immediately to this user side.Because server S ₃, S ₄And S ₆The coded data of last storage exists redundant, and the still enough user sides of the coded data block number of promptly being stored are in order to recover film B, though so server S ₅Parallel download service no longer is provided, and user side can't be realized the parallel download of 4 ports, but in the correct recovery that still can guarantee film B by the parallel download of long slightly 3 ports.When the coded data packet number of receiving when this user side enough decoded B, user side sent one " stopping sending request Cp " to server S ₃, S ₄And S ₆, server S ₃, S ₄And S ₆Just stop sending.

Claims (3)

1, a kind of network data concast transmission method based on the distributed coding storage is characterized in that this method may further comprise the steps:

(1) data and the coded message behind the coding of storage process respectively on a plurality of servers of network;

(2) user side sends the request of transmission data to above-mentioned a plurality of servers by network;

(3) after above-mentioned a plurality of server receives the transmission request of data of user sides, send confirmation and coded message to user side respectively, and with above-mentioned through after the packing data behind the coding by specified circuit by sending to user side;

(4) after user side is received above-mentioned confirmation, from above-mentioned coded message, obtain the packet number N that needs reception;

(5) user side receives from above-mentioned a plurality of servers and adds up to the packet of above-mentioned N, and decodes, if decode successfully, then send the request of termination,, then continue to receive data if decoding is unsuccessful to server, until decoding successfully, and send the request of termination to server.

2, the method for claim 1 is characterized in that wherein saidly data are carried out Methods for Coding comprising following each step:

(1) data waiting for transmission are divided into a K equal portions original data block, and definite random number generation function and random number generation seed, this random number generation function generates seed according to this random number and produces a random number sequence { r _i, i=1,2 ...;

(2) from above-mentioned random number sequence, extract first random number r ₁, according to cumulative distribution function C _D(x) judge, if satisfy C _D(d-1)＜r≤C _D(d), then with integer d as the coding number of degrees;

(3) from above-mentioned random number sequence, extract second to d+1 random number, round after this d random number multiplied each other with K respectively, obtain the numbering of d original data block, if have mutually the same numbering in above-mentioned d the numbering, then continue to extract and round after follow-up 1 random number and K multiply each other, obtain the numbering of new original data block, and it is replaced above-mentioned identical numbering, repeat this process, until the numbering that obtains a mutually different d original data block;

(4) will carry out XOR with the corresponding original data block of above-mentioned mutually different numbering, obtain a coded data block, and define this coded data block and there is encoding relation in d original data block;

(5) all random numbers that deletion was extracted from above-mentioned random number sequence, finish until coding repeating step (2)～(4).

3, the method for claim 1 is characterized in that the wherein said method that data are decoded comprises following each step:

(1) according to the coded message that receives from each server, obtain the random number generation seed that each server uses, the random number generation function that uses according to coding produces a random number sequence { r identical with coding _i, i=1,2 ...;

(2) from above-mentioned random number sequence, extract first random number r ₁, according to cumulative distribution function C _D(x) judge, if satisfy C _D(d-1)＜r ₁≤ C _D(d), then with integer d as the coding number of degrees;

(3) from above-mentioned random number sequence, extract second to d+1 random number, round after this d random number is multiplied each other with K respectively, obtain the numbering of d original data block;

(4) preceding d+1 random number of deletion from above-mentioned random number sequence, repeating step (2) and (3) are until obtaining the encoding relation that all coded data blocks and all original data blocks exist;

(5) according to above-mentioned encoding relation, the searching coding number of degrees are 1 coded data block, if seek failure, then carry out step (8), as if searching out, then obtain the original data block corresponding with this coded data block;

(6) there is the value of the coded data block of encoding relation to carry out XOR successively with this original data block the value of above-mentioned original data block and all, the value behind the XOR is replaced the original encoding data block value successively, replace the encoding relation of this original data block of back deletion;

(7) repeat above-mentioned steps (5) and (6);

(8) if all original data blocks are resumed, then the report decoding is finished, if do not recover all original data blocks, then the report decoding is not finished.

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