CN101465791A - Document transmission method based on unidirection link - Google Patents

Abstract

The invention discloses a file transfer method based on unidirectional links, which is used to transfer a file to a plurality of users in a unidirectional transmission network. The method takes a file attribute table to describe the file composition, the file attribute and the transfer segmentation parameters of the data traffic and partitions the file to be transferred into data patches at equal length, and if the last data patch is not long enough, the last patch can be supplemented through 0x00; then the file patches are packed into data patch packets according to a data patch encapsulation grammar, and a data block is checked to form a parity block which closely follows the data block; and then the parity block is partitioned into pieces which are then packed into parity piece packets which are transferred closely following the corresponding data patch packets. A terminal first receives and analyzes the file attribute table and then completely restores a file and a catalogue structure consistent with the originating terminal at home according to the information indicated by the file attribute table. The method simply and effectively realizes the transmission and reception of the file in the unidirectional transmission network and the users can conveniently and quickly receive the file data traffic, thus greatly satisfying the requirements of the users.

Description

A kind of document transmission method based on one way link

Technical field

The invention belongs to communication and broadcast technology field, relate in particular to a kind of file division encapsulation transfer approach based on the one way link transmission.

Background technology

Be accompanied by the fast development of mechanics of communication and digital technology, the user becomes more and more urgent to obtaining with shared demand of information resources, and is also more and more diversified.How various files transmit in network quickly and efficiently as the important carrier of information, are the important topic of pendulum in face of ours.

At present, the Network Transmission of file has a lot of modes, as relatively commonly used file transfer protocol (FTP) (File Transfer Protocal arranged, be abbreviated as FTP) service, it is operated in the inventionthe open systems interconnection model layer 7 of (Open System Interconnection is called for short osi model), transmission control protocol model (Transmission Control Protocol, be called for short the TCP model) the 4th layer on, i.e. application layer.Like this, FTP client will be through the process of " three-way handshake " widely known before connecting with server, for the transmission of data provides reliable assurance.Now, point-to-point (peer-to-peer is called for short P2P) transmission of using often, BT (BitTorrent agreement) also is a kind of file transfer mode.

But, at the one-way transmission network,, identical file is transferred to a plurality of users such as radio network, still there is not good file transfer solution at present.

Summary of the invention

Technical problem to be solved by this invention provides a kind of encapsulation and transmission method based on the file on the one way link, and the file that this method will need to transmit is cut apart transmission, can realize the transmission of file data in unidirectional transmission system quickly and efficiently.

For solving the problems of the technologies described above, the technical solution used in the present invention comprises the steps:

The first step is described as file attribute table (File Attribute Table is abbreviated as FAT) file with the file parameters of the file of needs transmission;

Second step, as required the FAT file is carried out burst and handle, be packaged into the transmission of FAT sheet bag according to FAT encapsulation grammer again;

The 3rd step generated the file sheet of unified length with the file fragmentation of needs transmission, was filled when last file leaf length is not enough, was packaged into file sheet bag according to file sheet encapsulation grammer again;

In the 4th step,, and it is carried out verification form check block immediately following this blocks of files with some file sheet composing document pieces;

The 5th step, as required check block is carried out burst and handle, be packaged into verification sheet bag according to verification sheet encapsulation grammer again;

The 6th step, transfer files sheet bag and immediately following thereafter verification sheet bag.

Information such as the file formation of described FAT file description data service, file attribute, transmission partitioning parameters adopt XML (extensible Markup Language) (The Extensible Markup Language is abbreviated as XML) syntactic description.The present invention can become n FAT sheet with a FAT file division as the case may be, and the length of each FAT sheet generally is no more than 4095 bytes, and the n value in 1～256 scope, is represented not cut apart when n equals 1 usually.

Described FAT sheet bag comprises FAT packet header, FAT payload and CRC_32.Wherein, FAT packet header comprises resource identification, when the anter sequence number, upgrade sequence number, type of coding, rear panel sequence number and leaf length, the FAT payload carries FAT sheet data, CRC_32 is 32 cyclic check positions of the FAT payload being carried out verification.

Described file sheet bag is made up of file sheet packet header and file sheet payload.File sheet packet header comprises resource identification, piece sequence number, sheet sequence number and upgrades sequence number; File sheet payload carries actual file sheet.

The grammer encapsulating structure of described verification sheet bag is identical with file sheet bag, comprises verification sheet packet header and verification sheet payload.Verification sheet packet header comprises resource identification, piece sequence number, sheet sequence number and upgrades sequence number; Verification sheet payload carries actual verification sheet.

The present invention adopts file formation, file attribute, the transmission partitioning parameters information of FAT file description data service, by file is cut apart, operation such as error correction, encapsulation forms file sheet bag and verification sheet bag, thereby realized transmission and the reception of file in the one-way transmission network simply and effectively, the user can conveniently receive the file data business, thereby meets consumers' demand greatly.

Description of drawings

Fig. 1 is cut apart schematic diagram for FAT;

Fig. 2 is a FAT sheet pack arrangement schematic diagram;

Fig. 3 is the file division schematic diagram;

Fig. 4 is a blocks of files verification schematic diagram;

Fig. 5 is file sheet/verification sheet pack arrangement schematic diagram;

Fig. 6 is the model structure chart of FAT file root element;

Fig. 7 is the file path information element data type model structure chart of (being called for short FDIType);

Fig. 8 is the file attribute information element data type model structure chart of (being called for short FAIType);

Fig. 9 is the model structure chart of transmission information element data type (being called for short TransferInfoType);

Figure 10 is the content information element data type model structure chart of (being called for short ContentInfoType);

Figure 11 is the carve information element data type model structure chart of (being called for short SegmentInfoType);

Figure 12 is the FEC information element data type model structure chart of (being called for short FECInfoType);

Figure 13 is the model structure chart of fileinfo protection element data type (being called for short ProtectionInfoType);

Figure 14 is the life period element data type model structure chart of (being called for short LifePeriod).

Embodiment

Below in conjunction with the drawings and specific embodiments the present invention is further specified.

At first, the definition of data business is to be made up of some files, and file can be in same catalogue, also can be in different catalogues, and bibliographic structure can divide multilayer.The present invention adopts file formation, file attribute, the transmission partitioning parameters information of file attribute table (File Attribute Table is called for short FAT) data of description business.Specific implementation can adopt XML (extensible Markup Language) (TheExtensible Markup Language is abbreviated as XML) syntactic description file attribute table, and file attribute table itself also forms a file.Before the file sendaisle was set up, the present invention at first generated the FAT file.Terminal at first receives, resolves the FAT file, according to the information of FAT file indication in this locality complete recovering and consistent file and the bibliographic structure of making a start.

Figure 1 shows that FAT file division schematic diagram.The present invention becomes the FAT sheet with the FAT file division as required, and sequence number is 0,1 ... n-1, n altogether, n span 1～256 is not cut apart when n equals 1 expression.The FAT file adopts different encapsulation grammers to cut apart transmission with ordinary file.Terminal does not need prior information just can receive the FAT file.

Figure 2 shows that the FAT sheet seals the assembling structure schematic diagram.As shown in the figure, FAT sheet bag is made up of FAT packet header, FAT payload and CRC_32.

FAT packet header comprises resource identification, when the anter sequence number, upgrade sequence number, type of coding, rear panel sequence number and leaf length.Wherein, the resource identification field is used to identify a FAT file data business; When the anter sequence number field is used to represent the sequence number of current FAT sheet, if FAT file burst not, then this field value is 0; Upgrade the renewal sequence number that sequence number field is used to represent current resource, if FAT information changes, this field circulates to increase progressively and adds 1; The type of coding field is used to represent the type of coding of FAT file employing; Rear panel sequence number field is used to identify the sequence number of last FAT sheet, if FAT file burst not, then this field value is 0; The leaf length field is used to represent the length of current FAT sheet.

The FAT payload field is carried FAT sheet data, and its length is indicated by " leaf length " field in the FAT packet header.

CRC_32 is 32 cyclic check fields, is used for the FAT payload is carried out verification.

Figure 3 shows that the file division schematic diagram.As shown in the figure, at first file division is become some isometric file sheets, the length of each file sheet generally is no more than 65535 bytes, need fill when last file leaf length is not enough, present embodiment adopts 0x00 to fill, and can certainly adopt other filling modes.A plurality of file sheets are formed a blocks of files, because the length of file sheet is changeable, the quantity of the file sheet of composing document piece neither be only definite, but generally be no more than 16383.Can be divided into two types of A, B according to the file sheet quantity difference in the blocks of files, if file sheet quantity equates then have only type A.Distinguish category-A blocks of files and category-B blocks of files, help easier realization verification.The file error correction is undertaken by blocks of files, and the error correction data that obtains is called check block.Check block is divided into some, is referred to as the verification sheet, and length equates that with the file sheet verification sheet and file sheet serial number are seen Fig. 4.

Figure 5 shows that file sheet/verification sheet pack arrangement schematic diagram, the file sheet with forming after the file division is combined into blocks of files, then blocks of files is carried out verification operation and generates check block, blocks of files and check block is cut apart to be packaged into file sheet/verification sheet bag at last.File sheet and verification sheet bag adopt unified grammer encapsulating structure, comprise file sheet/verification sheet packet header and file sheet/verification sheet payload.

File sheet/verification sheet packet header comprises resource identification, piece sequence number, sheet sequence number and upgrades sequence number.Wherein, the resource identification field is used for file of unique identification; The piece sequence number field is used to represent the sequence number of the blocks of files/check block of current file sheet/verification sheet institute subordinate; The sheet sequence number field is used to represent the current file sheet/sequence number of verification sheet in blocks of files/check block; Upgrade the renewal sequence number that sequence number field is used to represent current resource.

File sheet/verification sheet payload carries actual file sheet or verification sheet, and its length is specified by the FAT file, by file sheet sequence number identification file sheet and verification sheet.

In the one way link system, the file data that transmits is made up of the file of series of discrete, each file is except data message, the information that also has some description this document attributes, as filename, length, compress mode etc., terminal not only needs correctly to receive data, also will receive the descriptor of file attribute, so that can recover and the consistent file of making a start.Terminal at first receives, resolves the FAT file, according to the information of FAT file indication in this locality complete recovering and consistent file and the bibliographic structure of making a start, specifically may further comprise the steps:

The first step, the user at first obtains the FAT sheet, if the FAT file does not have burst, then this FAT sheet is complete FAT file, if the FAT file is by burst, then splice, and resolve, recover complete FAT file according to " type of coding " field according to " when the anter sequence number " in the FAT sheet packet header and " rear panel sequence number " field information;

In second step, the user obtains file sheet/verification sheet by the data decapsulation;

In the 3rd step, the user is spliced the acquisition file data by parameter in the FAT file to the file sheet that obtains.

Terminal does not need prior information just can receive the FAT file, and must could correctly receive according to the transmission information of cutting apart of FAT file indication for data service file terminal.

Present embodiment adopts the data model of XML description document attribute, and the file attribute data that adopt the XML mode to describe are the examples that generate according to this model.Below describe by business parameters data example of the present invention:

Fig. 6 is the model structure chart of FAT root element.The semantical definition of FAT root element sees Table 1.

Table 1 root element semanteme

Field	Semantic
		FDI	The file path information element
FAI	The file attribute information element
		DefaultFECInfo	Acquiescence FEC parameter information element
MaxVersion	The major release attribute of FAT, if major release changes, terminal need rebuild money

	The corresponding relation of source sign and file.
		MinVersion	The minor release/point release attribute of FAT, if only there is minor release/point release to change, the corresponding relation of resource identification and file remains unchanged.

Described file path information element (FDI) has been described file path information, and the data type of this element is defined by FDIType, and its mode configuration is seen Fig. 7, and the semantical definition of FDIType sees Table 2.

Table 2 FDIType semanteme

Field	Semantic
		DirName	Path elements, the path of description document.
DirID	The ID of trace route path element, by this element can and path elements between set up corresponding relation.
		DirLevel	The path-level attribute, the rank of expression file path.

Described file attribute information element (FAI) has been described file attribute information, and the data type of this element is defined by FAIType, and its mode configuration is seen Fig. 8.The semantical definition of FAIType sees Table 3.

Table 3 FAIType semanteme

Field	Semantic
		TransferInfo	The transmission information element
ContentInfo	The content information element
		SegmentationInfo	The carve information element
FECInfo	The FEC information element
		ProtectionInfo	The protection information element
Resource_ID	The resource identification attribute is represented this FAI element corresponding file resource.
		UpdateIndex	Upgrade the sequence number attribute, represent the renewal sequence number of this FAI element.

Described transmission information element (TransferInfo) has been described with some relevant attribute informations of file transfer, and the data type of this element is defined by TransferInfoType, and its mode configuration is seen Fig. 9.The semantical definition of TransferInfoType sees Table 4.

Table 4 TransferInfoType semanteme

Field	Semantic
		DirID	File path sign, corresponding with DirID in the FDI element, can set up the path relation of file according to this sign.
File_name	Filename
		Life_period	The life cycle element

Described content information element (ContentInfo) has been described with some relevant attribute informations of file content, and the data type of this element is defined by ContentInfoType, and its mode configuration is seen Figure 10.The semantical definition of ContentInfoType sees Table 5.

Table 5 ContentInfoType semanteme

Field	Semantic
		container_file	Whether the indication presents is a container

MIME_type	The file mime type
		File_length	The file original length
File_encoding	Document No.
		File_encoding_length	Total length behind the document No.
MD5_code	The MD5 sign indicating number, the base64Binary type
		Content_lingual_special	With the relevant content description element of languages
Title	Content title
		Digest	Synopsis
Keyword	Content keyword, between the different keywords with '; ' separate.
		Lang	The content description attribute of an element, expression languages information.
Private_info	The content private information keeps.

Described carve information element (SegmentationInfo) has been described the carve information of file, and the data type of this element is defined by SegmentationInfoType, and its model structure chart is seen Figure 11.The semanteme of SegmentationInfoType sees Table 6.

Table 6 SegmentationInfoType semanteme

Field	Semantic
		Slice_length	The size of file sheet, unit is a byte
A_block_count	The quantity of type A blocks of files
		B_block_count	The quantity of type B part piece
Total_block_count	The blocks of files sum equals A_block_count and B_block_count sum.
		Slice_count_for_A	The quantity of file sheet in the type A blocks of files
Slice_count_for_B	The quantity of file sheet in the type B blocks of files
		Fec_slice_count_for_A	The quantity of type A blocks of files verification sheet
Fec_slice_count_for_B	The quantity of type B blocks of files verification sheet

Described FEC information element (FECInfo) has been described the file forward error correction information, and FECInfoType is the dtd of this element, and its mode configuration is seen Figure 12.The semanteme of FECInfoType sees Table 7.

Table 7 FECInfoType semanteme

Field	Semantic
		algorithm	Algorithm types

Described file protect information element (ProtectionInfo) has been described file protect information, and ProtectionInfoType is the dtd of this element, and its model structure chart is seen Figure 13.The semanteme of ProtectionInfoType sees Table 8.

Table 8 ProtectionInfoType semanteme

Field	Semantic
		Protection_level	Protection level, the protection level of expression file content.
Level_description	Protection level is described, to further describing of the protection level of file content.

Described life cycle element (life_period) has been described file life cycle information, and LifePeriod is the dtd of this element, and its model structure chart is seen Figure 14.The semanteme of LifePeriod sees Table 9.

Table 9 LifePeriod semanteme

Field	Semantic
		time_unit_indic	Chronomere indication, the binding hours chronomere indication value that the expression file uses is defined as follows: 0: hour 1: days 2: week 3: month
show_time	The binding hours that the expression file uses is determined the time cycle according to chronomere's indication, shows that the restriction of time is as follows: 0: limit 1～60:1 chronomere no service time to 60 chronomeres 61～63: reservation

To sum up, the present invention can be isometric file sheet according to demand with file fragmentation and generate corresponding verification sheet, make it to be adapted to the transmission of one way link.For a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (9)

1, a kind of document transmission method based on one way link is characterized in that comprising the steps:

The first step is described as file attribute table FAT file with the file parameters of the file of needs transmission;

Second step, as required the FAT file is carried out burst and handle, be packaged into the transmission of FAT sheet bag according to FAT encapsulation grammer again;

The 3rd step generated the file sheet of unified length with the file fragmentation of needs transmission, was filled when last file leaf length is not enough, was packaged into file sheet bag according to file sheet encapsulation grammer again;

In the 4th step,, and it is carried out verification form check block immediately following this blocks of files with some file sheet composing document pieces;

The 5th step, as required check block is carried out burst and handle, be packaged into verification sheet bag according to verification sheet encapsulation grammer again;

The 6th step, transfer files sheet bag and immediately following thereafter verification sheet bag.

2, document transmission method according to claim 1 is characterized in that, the root element semantical definition of described FAT file is as follows:

Field Semantic FDI The file path information element; FAI The file attribute information element; DefaultFECInfo Acquiescence FEC parameter information element; MaxVersion The major release attribute of FAT, if major release changes, terminal need rebuild the corresponding relation of resource identification and file; MinVersion The minor release/point release attribute of FAT, if only there is minor release/point release to change, the corresponding relation of resource identification and file remains unchanged.

3, document transmission method according to claim 2 is characterized in that, the routing information of described file path information element FDI description document, and its semantical definition is as follows:

Field Semantic DirName Path elements, the path of description document; DirID The ID of trace route path element, by this element can and path elements between set up corresponding relation; DirLevel The path-level attribute, the rank of expression file path.

4, document transmission method according to claim 3 is characterized in that, the attribute information of described file attribute information element FAI description document, and its semantical definition is as follows:

Field Semantic TransferInfo The transmission information element; ContentInfo The content information element; SegmentationInfo The carve information element; FECInfo The FEC information element;

ProtectionInfo The protection information element; Resource_ID The resource identification attribute is represented this FAI element corresponding file resource; UpdateIndex Upgrade the sequence number attribute, represent the renewal sequence number of this FAI element.

5, according to any described document transmission method in the claim 1 to 4, it is characterized in that, in described second step, as the case may be, a FAT file division is become n FAT sheet, and the n span is 1～256, and the length of each FAT sheet is no more than 4095 bytes.

6, document transmission method according to claim 5 is characterized in that, described FAT sheet bag comprises FAT packet header, FAT payload and CRC_32;

FAT packet header comprises resource identification, when the anter sequence number, upgrade sequence number, type of coding, rear panel sequence number and leaf length, the FAT payload carries FAT sheet data, CRC_32 is 32 cyclic check positions of the FAT payload being carried out verification.

7, document transmission method according to claim 6 is characterized in that, described file sheet bag is made up of file sheet packet header and file sheet payload; File sheet packet header comprises resource identification, piece sequence number, sheet sequence number and upgrades sequence number; File sheet payload carries actual file sheet;

Described verification sheet bag is made up of verification sheet packet header and verification sheet payload; Verification sheet packet header comprises resource identification, piece sequence number, sheet sequence number and upgrades sequence number; Verification sheet payload carries actual verification sheet.

8, document transmission method according to claim 7 is characterized in that, the equal in length of the length of described verification sheet and file sheet; The sheet sequence number serial number of the sheet sequence number of verification sheet and file sheet.

9, a kind of method that receives according to the file of the described method transmission of claim 8 is characterized in that comprising the steps:

The first step, the user at first obtains the FAT sheet, if the FAT file does not have burst, then this FAT sheet is complete FAT file, if the FAT file is by burst, then splice, and resolve, recover complete FAT file according to " type of coding " field according to " when the anter sequence number " in the FAT sheet packet header and " rear panel sequence number " field information;

In second step, the user obtains file sheet and verification sheet by the data decapsulation;

In the 3rd step, the user is spliced the acquisition file data by parameter in the FAT file to the file sheet that obtains.

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