KR101568390B1 - Method for transmitting and receiving data using bloom filter - Google Patents

Abstract

A data receiving method operating in a receiving terminal is disclosed. The data receiving method includes receiving a packet from a transmitting terminal, checking whether the received packet is encoded, and determining whether a reference value included in the encoded packet is a reference value, if the received packet is an encoded packet, And decoding the encoded packet by replacing with a chunk corresponding to a fingerprint corresponding to the encoded fingerprint.

Description

TECHNICAL FIELD The present invention relates to a method for transmitting and receiving data using a Bloom filter,

More particularly, the present invention relates to a method of transmitting / receiving data using a Bloom filter, and more particularly, to a method and apparatus for predicting a next packet to be received from a received packet, a capacity of a packet to be transmitted using a Bloom filter including prediction information To a data transmission / reception method capable of reducing traffic.

As a general method for reducing the traffic of a network, a web cache technique is widely used. The web cache technique utilizes a cache server provided between a content providing server and a user terminal. Since the cache server stores frequently requested contents, a user using the user terminal can receive content from the cache server located near by the user terminal rather than the content providing server located remotely from the user terminal have.

However, since the general web caching technique uses the uniform resource locator (URL) information of HTTP (Hyper Text Protocol) to identify the same content, it can not be used in various application layer protocols. In addition, since the contents having the same contents often have different URL information on the Internet, the method of distinguishing contents using the contents also has not provided reliability.

As a technique for solving the problem of the above-described web cache technique, there is a protocol-independent redundancy elimination technique. The deduplication technique is a technique for reducing traffic transmitted redundantly in a network, and can be used independently of an upper protocol because it mainly targets packets at a network layer, which is a network 3 layer.

FIG. 1 illustrates a system for performing a conventional de-duplication technique.

Referring to FIG. 1, the deduplication system 1 includes a transmitting terminal 3 and a receiving terminal 5, which are fixed two terminals located on the wire.

The transmitting terminal 3 and the receiving terminal 5 share traffic information between the transmitting terminal 3 and the receiving terminal 5 to reduce traffic between the two terminals by eliminating already transmitted traffic, that is, duplicated traffic.

The transmitting terminal 3 can remove the traffic by considering the packet P1 as a byte stream and removing the already transmitted part in the packet P1. That is, the transmitting terminal 3 divides the data payload of the packet P1 into chunks, calculates a hash value of each of the plurality of chunks C1 to C5, Based fingerprint. ≪ / RTI >

If the generated fingerprint is already stored in the fingerprint storage in the transmitting terminal 3, it may mean that the data corresponding to the fingerprint is also cached on the receiving terminal 5 side. Thus, the transmitting terminal 3 replaces the chunks C2, C4 determined to have already been transmitted among the plurality of chunks in the packet P1 with the corresponding fingerprints F2, F4. The process of reducing the size of a packet by replacing duplicated chunks with fingerprints is called encoding. The transmitting terminal 3 transmits the encoded packet P2 to the receiving terminal 5.

The receiving terminal 5 retrieves the fingerprints F2 and F4 in the received packet P3 from its fingerprint store and replaces the fingerprints F2 and F4 with the corresponding actual data C2 and C4 And restores the packet. The above packet restoration process is called decoding.

As a result, the network traffic between the transmitting terminal 3 and the receiving terminal 5 can be efficiently reduced because the size of the fingerprint is very small compared to the size of the chunk.

The existing deduplication technique provides an efficient solution that can be used on a wired network where the error rate of the packets transmitted between the terminals is very low and communication between the terminals is continuously possible so that mutual cache information can be easily shared.

However, it is difficult to apply the existing deduplication technique in direct communication between wireless terminals in which the error rate of the transmitted packets is high, sharing of cache information between terminals is difficult, and continuous communication is impossible.

Korean Patent Publication No. 0781218 Korean Patent Publication No. 2008-0087997

SUMMARY OF THE INVENTION The present invention provides a data transmission / reception method capable of predicting a next packet to be received from a received packet and reducing the capacity of a packet to be received next using a bloom filter including prediction information .

According to another aspect of the present invention, there is provided a method of receiving data from a receiving terminal, the method comprising: receiving a packet from a transmitting terminal; checking whether the received packet is encoded; And replacing the reference value included in the encoded packet with a chunk corresponding to the fingerprint corresponding to the reference value to decode the encoded packet.

And requesting the transmitting terminal to transmit an original packet to the received packet if the encoded packet can not be decoded in the decoding step.

Dividing the received packet into a plurality of chunks and generating a plurality of fingerprints, each corresponding to each of the plurality of chunks, if the received packet is not an encoded packet; Deriving the number of fingerprints belonging to each of a plurality of previously stored bloom filters among the fingerprints, and transmitting the bloom filter including the number of fingerprints exceeding a predetermined value to the transmitting terminal.

The data receiving method may further include requesting, by the transmitting terminal, transmission of an original packet for the received packet if there is no Bloom filter including the number exceeding the predetermined value.

In addition, the data receiving method may further include receiving, from the transmitting terminal, a next packet encoded using the Bloom filter.

Each of the plurality of Bloom filters may have fingerprints of each of the chunks included in each of the previously received packets.

A method for transmitting data in a transmitting terminal according to another exemplary embodiment of the present invention includes the steps of determining whether a Bloom filter is received from a receiving terminal, receiving a Bloom filter, and transmitting a source packet to be transmitted to the receiving terminal to a plurality of chunks And generating a plurality of fingerprints each corresponding to each of the plurality of chunks, wherein, among the plurality of chunks included in the divided packet, the plurality of fingerprints Generating an encoded packet by replacing a chunk corresponding to a fingerprint belonging to the Bloom filter with a reference value among the plurality of bloom filters, and transmitting the encoded packet to the receiving terminal.

The data transmission method may further include transmitting the original packet to the receiving terminal when the Bloom filter received from the receiving terminal does not exist.

The reference value may be part of a bit sequence or a byte sequence included in the fingerprint corresponding to the reference value.

The generating of the encoded packet may further include transmitting the original packet to the receiving terminal when there is no fingerprint belonging to the Bloom filter.

According to another embodiment of the present invention, a data transmission method operating in a transmitting terminal includes dividing an original packet to be transmitted to a receiving terminal into a plurality of chunks to generate divided packets, Generating a corresponding plurality of fingerprints, selecting a chunk corresponding to a fingerprint belonging to the bloom filter received from the receiving terminal from among the plurality of fingerprints, among the plurality of chunks included in the divided packet, To generate an encoded packet, and transmitting the encoded packet to the receiving terminal.

The reference value may be part of a bit sequence or a byte sequence included in the fingerprint belonging to the Bloom filter.

According to yet another embodiment of the present invention, a method of receiving data from a receiving terminal comprises receiving a packet from a transmitting terminal, dividing the received packet into a plurality of chunks, Selecting a chunk set having the highest association with the received packet among a plurality of chunk sets stored in advance, and transmitting the bloom filter included in the selected chunk set to the transmitting terminal And receiving the next packet from the transmitting terminal.

Wherein the next packet includes a reference value generated using fingerprints registered in the Bloom filter, and the data receiving method further comprises: comparing the reference value with a reference value corresponding to the reference value among a plurality of chunks included in the selected chunk set And replacing it with a chunk.

The data transmission / reception method according to the embodiment of the present invention has an effect of reducing the traffic by reducing the capacity of the next packet to be received based on the received packet.

In addition, the data transmission / reception method can efficiently reduce traffic without a synchronization process between the receiving terminal and the transmitting terminal by encoding the original packet using the Bloom filter received from the receiving terminal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to more fully understand the drawings recited in the detailed description of the present invention, a detailed description of each drawing is provided.
FIG. 1 illustrates a system for performing a conventional de-duplication technique.
2 illustrates a data communication system in accordance with an embodiment of the present invention.
3 is a functional block diagram of the receiving terminal shown in FIG.
FIG. 4 is a view for explaining the operation of the chunk set generation module shown in FIG.
FIG. 5 is a view for explaining the operation of the chunk set prediction module shown in FIG.
6 is a functional block diagram of the transmitting terminal shown in FIG.
FIG. 7 is a diagram for explaining an operation process of the encoding module shown in FIG.
FIG. 8 is a flowchart for explaining an operation in the receiving terminal shown in FIG. 2. FIG.
FIG. 9 is a flowchart for explaining the operation of the transmitting terminal shown in FIG. 2. FIG.

It is to be understood that the specific structural or functional description of embodiments of the present invention disclosed herein is for illustrative purposes only and is not intended to limit the scope of the inventive concept But may be embodied in many different forms and is not limited to the embodiments set forth herein.

The embodiments according to the concept of the present invention can make various changes and can take various forms, so that the embodiments are illustrated in the drawings and described in detail herein. It should be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to the particular forms disclosed, but includes all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms may be named for the purpose of distinguishing one element from another, for example, without departing from the scope of the right according to the concept of the present invention, the first element may be referred to as a second element, The component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like are used to specify that there are features, numbers, steps, operations, elements, parts or combinations thereof described herein, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning of the context in the relevant art and, unless explicitly defined herein, are to be interpreted as ideal or overly formal Do not.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings attached hereto.

2 illustrates a data communication system in accordance with an embodiment of the present invention.

Referring to FIG. 2, the data communication system 10 includes a receiving terminal 100 and a transmitting terminal 300.

The receiving terminal 100 may transmit and receive data or information with the transmitting terminal 300 using device-to-device communication. The inter-terminal direct communication refers to a communication method in which terminals located in the same cell or neighboring cells establish communication links with each other and then directly transmit and receive data through a communication link established without going through a base station.

The receiving terminal 100 and the transmitting terminal 300 may be a mobile phone, a smart phone, a personal digital assistant (PDA), a portable multimedia player (PMP), a personal computer (PC) A computer, an e-reader, or the like.

The transmitting terminal 300 may transmit data in units of packets to the receiving terminal 100 in response to a request from the receiving terminal 100 or in response to receiving a packet from an upper layer of the network. At this time, the transmitted packet may be a packet encoded by the transmitting terminal 300.

The receiving terminal 100 receives a packet from the transmitting terminal 300. The receiving terminal 100 may decode the received packet according to whether the received packet is encoded or not. In addition, if the received packet is not encoded, the receiving terminal 100 may divide the received packet into a plurality of chunks and generate a fingerprint of each of the plurality of chunks. In addition, the receiving terminal 100 may generate a bloom filter for the plurality of chunks and the plurality of fingerprints. The plurality of chunks, the plurality of fingerprints, and the Bloom filter may be referred to as chunk sets.

In addition, the receiving terminal 100 may determine the association between a plurality of chunk sets stored in the memory and the received packet, and predict or predict a next packet to be received according to the association. That is, the receiving terminal 100 determines whether or not a plurality of fingerprints included in the generated chunk set are previously received and belong to each of the plurality of chunk sets stored in the memory, Select a Bloom filter that contains a fingerprint of a certain number (d, d is a natural number) or more. The receiving terminal 100 determines a chunk set including the selected bloom filter as a predicted chunk set and transmits the bloom filter included in the predicted chunk set to the transmitting terminal 300.

When the transmitting terminal 300 receiving the Bloom filter tries to transmit the next packet to the receiving terminal 100, the transmitting terminal divides the packet into a plurality of chunks and generates fingerprints of the plurality of chunks can do. The transmitting terminal 300 determines whether each of the plurality of fingerprints belongs to the Bloom filter, and encodes the packet to be transmitted according to the determination result.

That is, when the fingerprint belonging to the Bloom filter is searched among the plurality of fingerprints, the transmitting terminal 300 replaces the chunk corresponding to the searched fingerprint with a reference value, and receives a packet containing the reference value To the terminal (100). As described above, the process of replacing the chunk in the packet with the reference value is referred to as incoding, and the packet including the reference value is referred to as an encoded packet.

The receiving terminal 100 may receive the encoded packet from the transmitting terminal 300 and replace the reference value in the received packet with a chunk. The process of restoring the original packet, which is the packet that the transmitting terminal 300 has tried to transmit, by replacing the reference values in the received packet with chunks, is called decoding.

As described above, the transmitting terminal 300 has an effect of reducing the traffic by transmitting the encoded packet to the receiving terminal 100, and the receiving terminal efficiently exchanges the packet by replacing the reference value in the encoded packet with the chunk Can be restored.

3 is a functional block diagram of the receiving terminal shown in FIG.

2 and 3, the receiving terminal 100 includes a transmission / reception module 110, a chunk set generation module 130, a chunk set prediction module 140, a decoding module 150, a memory 170, (Not shown).

The transmission / reception module 110 receives the packet from the transmission terminal 300 or transmits the bloom filter to the transmission terminal 300 under the control of the control module 190. The packet may be an encoded packet. The received packet may be stored in the memory 170 by the control module 190.

The chunk set generation module 130 divides a packet received through the transmission / reception module 110 into a plurality of chunks and generates a fingerprint of each of the plurality of chunks under the control of the control module 190. The plurality of fingerprints may be the result itself of a hash function (e.g., SHA-1) obtained by taking each of the plurality of chunks as an input value, a value containing the resultant value, or a value generated using the resultant value have. The process of generating a fingerprint is referred to as fingerprinting.

In addition, the chunk set generation module 130 generates one bloom filter corresponding to the plurality of chunks and the plurality of fingerprints. A collection or set of the plurality of chunks, the plurality of fingerprints, and the one Bloom filter is referred to as a chunk set. The generated chunk set may be stored in the memory 170 by the control module 190.

The chunk set prediction module 140 can predict the next packet to be received under the control of the control module 190. [ That is, the chunk set prediction module 140 may include a plurality of fingerprints included in the chunk set generated by the chunk set generation module 130 in each of a plurality of chunk sets previously stored in the memory 170 Is included in the Bloom filter. Chunk set prediction module 140 selects a Bloom filter that contains fingerprints of a predetermined number (d) or more among the plurality of fingerprints among a plurality of Bloom filters stored in memory 170. [ According to an embodiment, the chunk set prediction module 140 may select a Bloom filter that contains the most fingerprints of the plurality of fingerprints.

Chunk set prediction module 140 predicts a chunk set containing the selected filter as a predicted chunk set. Wherein the prediction chunk set is a chunk set that has high relevance to the most recently received packet or contains chunks most similar to the most recently received packet, The probability that at least one chunk of the plurality of chunks is included is high.

The bloom filter selected by the chunk set prediction module 140 may be transmitted to the transmitting terminal 300 by the sending / receiving module 110 under the control of the control module 190.

The decoding module 150 may decode the encoded packets under the control of the control module 190. [ Specifically, when the packet received from the transmitting terminal 300 is an encoded packet, the decoding module 150 extracts the reference value included in the encoded packet from the chunk corresponding to the corresponding chunk, that is, Lt; / RTI > can decode the packet by replacing it with a chunk corresponding to the fingerprint corresponding to the reference value.

The reference value included in the encoded packet may be a value capable of distinguishing or distinguishing a fingerprint corresponding to the reference value from a plurality of fingerprints included in the prediction chunk set. For example, the reference value may be implemented as w bits (or bytes), and the w bits (or bytes) may be a bit sequence or a byte sequence included in the fingerprint corresponding to the reference value sequency, and may specifically be the lower w bits (or bytes) of the fingerprint. According to an embodiment, the reference value may be a value indicating a sequence number of a fingerprint corresponding to the reference value among a plurality of fingerprints included in the prediction chunk set.

The memory 170 may include a program memory and a data memory. Programs for controlling the operation of the receiving terminal 100 may be stored in the program memory. Data generated during the execution of the programs may be stored in the data memory. Depending on the embodiment, the memory 170 may be referred to by other terms, such as a buffer or cache. However, the present invention is not limited thereto.

In addition, the memory 170 may include a space for storing a plurality of generated chunk sets and a space for storing a predicted chunk set.

The control module 190 controls the overall operation of the receiving terminal 100. That is, the control module 190 may control operations of the transmission / reception module 110, the chunk set generation module 130, the chunk set prediction module 140, the decoding module 150, and the memory 170.

In addition, the control module 190 may determine whether a packet received through the transmission / reception module 110 is an encoded packet, and may control the decoding module 150 to decode the encoded packet if the packet is an encoded packet . The control module 190 may transmit the original packet transmission request signal to the transmitting terminal 300 through the transmitting and receiving module 110. [

Herein, a module may mean a functional and structural combination of hardware for carrying out the technical idea of the present invention and software for driving the hardware. For example, the module may mean a logical unit of a predetermined code and a hardware resource for executing the predetermined code, and does not necessarily mean a physically connected code or a kind of hardware.

FIG. 4 is a view for explaining the operation of the chunk set generation module shown in FIG.

2 through 4, the chunk set generation module 130 may generate a chunk set from the received packet. Specifically, the chunk set generation module 130 may divide a packet into n chunks (n is a natural number of 2 or more) and generate n fingerprints corresponding to each of the n chunks. The size of the chunk and the size of the fingerprint may be predetermined. For example, the size of the chunk may be 64 bytes, and the size of the fingerprint may be 20 bytes. However, the size of the chunk and the size of the fingerprint are not limited thereto, .

In addition, the chunk set generation module 130 may generate one bloom filter (m is a natural number of 2 or more) implemented with m bits for recording the information of the n fingerprints. That is, the fingerprint of each of the n chunks is registered in the Bloom filter. As a result, the chunk set includes n chunks, n fingerprints, and one Bloom filter.

The chunk set generation module 130 uses k hash functions (k is a natural number of 2 or more) to generate the bloom filter, and each hash function has m types of input values, i.e., Output the values with equal probability. That is, in order for one fingerprint to be registered or added to the Bloom filter, k hash function values for the one fingerprint must be generated or calculated, and among the m bits included in the Bloom filter, The fingerprint can be registered in the bloom filter by setting the bit corresponding to the value to 1.

If a fingerprint belongs to the Bloom filter, it can be confirmed by the following procedure. After calculating k hash function values for the fingerprint, if the bit values corresponding to the respective hash function values in the Bloom filter are all 1, it can be determined that the fingerprint belongs to the Bloom filter.

The generated chunk set may be stored in the memory 170. The memory 170 may be allocated a space for storing a total of c chunk sets (c is a natural number). That is, since the capacity or size of the memory 170 is limited, a chunk set replacement policy can be utilized to store a new chunk set when all the allocated space is used.

According to an embodiment, when the memory 170 is utilized or named as a cache or buffer, the chunk set replacement policy may be referred to as cache replacement policy. The cache replacement policy may be a least recently used (LRU) scheme, a least frequently used (LFU) scheme, or a round robin scheme.

FIG. 5 is a view for explaining the operation of the chunk set prediction module shown in FIG.

Referring to FIGS. 2, 3 and 5, the chunk set prediction module 140 determines whether the first to n-th fingerprints included in the first chunk set generated by the chunk set generation module 130, It is possible to determine whether each fingerprint belongs to each of the second bloom filter to the p-th bloom filter included in the second to the p-th chunk set (p-1 = c) stored in the memory 170 .

Specifically, the chunk set prediction module 140 may derive the number of fingerprints belonging to the second bloom filter among the first-first fingerprint to the first-n fingerprint. Also, the chunk set prediction module 140 may derive the number of fingerprints belonging to the third bloom filter to the pbloom filter among the first-first fingerprint to the first-n fingerprint.

The chunk set prediction module 140 predicts a prediction chunk set based on the number of fingerprints included in each of the second bloom filter to the p-th bloom filter. For example, when only the number of fingerprints belonging to the third bloom filter is d (d is an arbitrary natural number) or more, the third chunk set is predicted as a predicted chunk set. In this case, the chunk set prediction module 140 may omit the process of deriving the number of fingerprints included in the fourth bloom filter to the pbloom filter.

The accuracy of the prediction and the frequency of the prediction are determined by the predetermined d value. That is, if the value of d is small, a chunk set including a small number of fingerprints can be selected as a predicted chunk set, so that the frequency of prediction increases but the relevance to the most recently received packet decreases. On the other hand, if the value of d is large, since a large number of fingerprints belong to one chunk set, the association with the received packet can be enhanced. However, since the number of chunk sets that can be selected by the prediction chunk set is small, the chance of reducing traffic by prediction can be reduced. That is, the prediction frequency can be lowered.

According to an embodiment, the chunk set prediction module 140 may predict a chunk set including a Bloom filter including the fingerprints of the second through p-th bloom filters as a predicted chunk set, A chunk set including a Bloom filter including the most fingerprints among the Bloom filters including the print can be predicted as a predicted chunk set.

The third bloom filter is transmitted to the transmitting terminal 300 through the transmitting / receiving module 110 under the control of the control module 190. Also, the control module 190 may replace at least one chunk set of the plurality of chunk sets stored in the memory 170 with the generated chunk set according to a cache replacement policy or a chunk set replacement policy.

6 is a functional block diagram of the transmitting terminal shown in FIG.

2 and 6, the transmitting terminal 300 includes a transmitting / receiving module 310, an encoding module 350, a memory 370, and a control module 390.

The transmission / reception module 310 transmits a packet to the receiving terminal 100 or receives a Bloom filter from the receiving terminal 100 under the control of the control module 390. The packet may be an encoded packet and the received bloom filter may be stored in memory 370 by control module 390. [

The encoding module 350 may encode the packet to be transmitted, i.e., the original packet, under the control of the control module 390. Specifically, the encoding module 350 may divide the original packet to be transmitted to the receiving terminal 100 into a plurality of chunks, and generate a fingerprint of each of the plurality of divided chunks. In addition, the encoding module 350 determines whether each of the generated plurality of fingerprints belongs to the bloom filter received from the receiving terminal 100. [ It is possible to obtain k hash results from each fingerprint and if the bit values corresponding to the k hash result values in the Bloom filter are all 1, it can be determined that the fingerprint belongs to the Bloom filter.

Encoding module 350 may change a chunk corresponding to the fingerprint to a reference value when determining that a fingerprint belongs to the Bloom filter. As described above, the process of converting or replacing at least one chunk of the original packet into a reference value is referred to as encoding, and a packet generated as a result of encoding is referred to as an encoded packet. The encoded packet can be transmitted to the receiving terminal 100 through the sending / receiving module 310 under the control of the control module 390.

The memory 370 may include a program memory and a data memory. Programs for controlling the operation of the transmitting terminal 300 may be stored in the program memory. Data generated during the execution of the programs may be stored in the data memory. In accordance with an embodiment, memory 370 may be referred to by other terms, such as a buffer or cache.

The control module 390 controls the overall operation of the transmitting terminal 300. That is, the control module 390 can control operations of the transmission / reception module 310, the encoding module 350, and the memory 370. The control module 390 determines whether to encode a packet to be transmitted according to the presence or absence of the bloom filter received through the transmission / reception module 310, and controls the encoding module 350 according to the determination to transmit the packet to be transmitted Can be encoded. Thus, according to the determination of the control module 390, the unencoded original packet may be transmitted or an encoded packet may be transmitted.

If the encoding module 350 fails to encode, that is, if the encoding module 350 can not find the fingerprint included in the bloom filter received from the receiving terminal 100, the control module 390 transmits / To the receiving terminal 100 via the module 310.

FIG. 7 is a diagram for explaining an operation process of the encoding module shown in FIG.

2, 6 and 7, the encoding module 350 divides an original packet 351, which is a packet to be transmitted, into chunks, and generates a divided packet 353 including a plurality of chunks. The encoding module 350 may also generate a fingerprint corresponding to each of the plurality of chunks. For example, the divided packet 353 may include the first chunk CK1 to the fifth chunk CK5, and may include a first fingerprint corresponding to each of the first chunk CK1 to the fifth chunk CK5 FP1) to the fifth fingerprint FP5 may be generated.

The encoding module 350 generates k hash function values (hash 1 to hash k) for each of the plurality of fingerprints FP1 to FP5 and generates a hash function Depending on the value of the bits corresponding to each of the values, it can be determined whether or not each fingerprint belongs to the Bloom filter. For example, the encoding module 350 may determine that the second fingerprint FP2 and the fourth fingerprint FP4 belong to the Bloom filter. In this case, the encoding module 350 generates the second chunk CK2 corresponding to the second fingerprint FP2 and the second chunk CK2 corresponding to the fourth fingerprint FP4 among the plurality of chunks included in the divided packet 353 Each of the fourth chunks CK4 may be replaced with a second reference value Ref2 and a fourth reference value Ref4. The second reference value Ref2 may mean the value of the lower w bits (or bytes) of the bits (or bytes) contained in the second fingerprint FP2, and the fourth reference value Ref4 (Or bytes) of the bits (or bytes) included in the 4-fingerprint (FP4).

As described above, the encoding module 350 may generate an encoded packet 355 by replacing a portion of the data (or chunk) contained in the original packet with a reference value. The encoded packet 355 may be transmitted by the control module 390 to the receiving terminal 100 via the sending and receiving module 310. [

FIG. 8 is a flowchart for explaining an operation in the receiving terminal shown in FIG. 2. FIG.

2, 3, and 8, the transmission / reception module 110 receives a packet from the transmission terminal 300 under the control of the control module 190 (S110).

The control module 190 determines whether the received packet is encoded, that is, whether it is an encoded packet or an unencoded packet (S120). If the received packet is an encoded packet, the decoding module 150 decodes the encoded packet under the control of the control module 190 (S130). The control module 190 determines whether or not decoding of the decoding module 150 is successful and the operation of the receiving terminal 100 is ended when the decoding module 150 succeeds in decoding. If the decoding module 150 does not succeed in decoding, the control module 190 may transmit a transmission request signal of the original packet to the transmitting terminal 300 through the transmitting / receiving module 110 (S190).

If the packet received from the transmitting terminal 300 is not an encoded packet, the chunk set generation module 130 generates a chunk set under the control of the control module 190 (S150). In addition, the chunk set prediction module 140 can predict a next packet to be received by selecting a chunk set highly correlated with the received packet (S160).

The control module 190 determines whether the chunk set prediction module 140 has succeeded in prediction at step S170 and ends the operation of the receiving terminal 100 when the chunk set prediction module 140 fails to predict. When the chunk set prediction module 140 successfully predicts a next packet to be received, the control module 190 transmits the bloom filter included in the predicted chunk set to the transmitting terminal 300 through the transmission / reception module 110 (S180).

FIG. 9 is a flowchart for explaining the operation of the transmitting terminal shown in FIG. 2. FIG.

Referring to FIGS. 2, 6 and 9, in order to transmit a packet, the control module 390 determines whether there is a bloom filter received from the receiving terminal 100 (S310). If there is no Bloom filter received from the receiving terminal 100, the sending / receiving module 310 transmits the original packet, i.e., the unencoded packet to the receiving terminal 100 under the control of the control module 390 (S320) .

When there is a Bloom filter received from the receiving terminal 100, the encoding module 350 generates a packet segmented from the original packet under the control of the control module 390 (S330). In addition, the encoding module 350 generates a fingerprint of each of the plurality of chunks included in the divided packet (S340).

The encoding module 350 determines whether each of the generated plurality of fingerprints belongs to the Bloom filter received from the receiving terminal 100 (S350). If there is no fingerprint belonging to the Bloom filter among the plurality of fingerprints, the control module 390 transmits the original packet to the receiving terminal 100 through the sending / receiving module 310 (S320) The operation of the terminal 300 is terminated.

If there is at least one fingerprint belonging to the Bloom filter among the plurality of fingerprints, the encoding module 350 generates an encoded packet from the divided packet (S360). The generated encoded packet is transmitted to the receiving terminal 100 by the transmission / reception module 310 under the control of the control module 390 (S370).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

1: deduplication system 3: transmitting terminal
5: receiving terminal 10: data communication system
100: receiving terminal 110: transmitting / receiving module
130: chunk set generation module 140: chunk set prediction module
150: decoding module 170: memory
190: control module 300: transmitting terminal
310: Transmitting / receiving module 350: Encoding module
351: packet to be transmitted 353:
355: Encoded packet 370: Memory
390: Control module

Claims (14)

A method for receiving data in a receiving terminal,
Receiving a packet from a transmitting terminal;
Confirming whether the received packet is encoded;
If the received packet is an encoded packet, decoding the encoded packet by replacing a reference value included in the encoded packet with a chunk corresponding to a fingerprint corresponding to the reference value;
If the received packet is not an encoded packet,
Dividing the received packet into a plurality of chunks, each generating a plurality of fingerprints corresponding to each of the plurality of chunks;
Deriving a number of fingerprints pertaining to each of a plurality of previously stored bloom filters of the plurality of fingerprints; And
And transmitting to the transmitting terminal a Bloom filter including a predetermined number or more of fingerprints among the plurality of fingerprints. The method according to claim 1,
And requesting the transmitting terminal to transmit an original packet to the received packet if the encoded packet can not be decoded in the decoding step. delete The method according to claim 1,
Further comprising the step of requesting the transmitting terminal to transmit an original packet for the received packet if there is no Bloom filter including the predetermined number or more of fingerprints. The method according to claim 1,
Further comprising receiving, from the transmitting terminal, the next packet encoded using the Bloom filter. The method according to claim 1,
Wherein fingerprints of each of the chunks contained in each of the previously received packets are registered in each of the plurality of Bloom filters. A method for transmitting data in a transmitting terminal,
Determining whether to receive the bloom filter generated by the receiving terminal from the receiving terminal;
Generating a divided packet by dividing an original packet to be transmitted to the receiving terminal into a plurality of chunks when the Bloom filter is received and generating a plurality of fingerprints each corresponding to each of the plurality of chunks ;
Generating an encoded packet by replacing a chunk corresponding to a fingerprint belonging to the Bloom filter with a reference value among the plurality of chunks included in the divided packet; And
And transmitting the encoded packet to the receiving terminal,
Wherein the Bloom filter includes a plurality of second fingerprints corresponding to each of a plurality of second chunks divided from a second packet transmitted from the transmitting terminal to the receiving terminal, A bloom filter comprising a predetermined number or more of fingerprints,
Data transmission method. 8. The method of claim 7,
And transmitting the original packet to the receiving terminal when there is no Bloom filter received from the receiving terminal. 8. The method of claim 7,
Wherein the reference value is a part of a bit sequence or a byte sequence included in the fingerprint corresponding to the reference value. 8. The method of claim 7,
And transmitting the original packet to the receiving terminal when the fingerprint belonging to the Bloom filter does not exist in the step of generating the encoded packet. A method for transmitting data in a transmitting terminal,
Dividing an original packet to be transmitted to a receiving terminal into a plurality of chunks to generate a divided packet, and generating a plurality of fingerprints each corresponding to each of the plurality of chunks;
Generating an encoded packet by replacing a chunk corresponding to a fingerprint belonging to a Bloom filter received from the receiving terminal with a reference value among the plurality of chunks included in the divided packet; And
And transmitting the encoded packet to the receiving terminal,
Wherein the Bloom filter includes a plurality of second fingerprints corresponding to each of a plurality of second chunks divided from a second packet transmitted from the transmitting terminal to the receiving terminal, A bloom filter comprising a predetermined number or more of fingerprints,
Data transmission method. 12. The method of claim 11,
Wherein the reference value is part of a bit sequence or a byte sequence included in the fingerprint belonging to the Bloom filter. A method for receiving data in a receiving terminal,
Receiving a packet from a transmitting terminal;
Dividing the received packet into a plurality of chunks, each generating a plurality of fingerprints corresponding to each of the plurality of chunks;
Selecting a chunk set having the highest correlation with the received packet among a plurality of chunk sets stored in advance;
Transmitting a Bloom filter included in the selected chunk set to the transmitting terminal; And
Receiving a next packet from the transmitting terminal,
Wherein the Bloom filter includes a plurality of second fingerprints corresponding to each of a plurality of second chunks divided from a second packet received from the transmitting terminal among bloom filters included in each of the plurality of chunk sets A Bloom filter including a predetermined number or more of fingerprints,
A method for receiving data. 14. The method of claim 13,
Wherein the next packet includes a reference value generated using a fingerprint registered in the Bloom filter,
Wherein the data receiving method further comprises replacing the reference value with a chunk corresponding to the reference value among a plurality of chunks included in the selected chunk set.

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