US5521940A — Method and device for the compression and decompr…

Claim 1

Independent Claim 216 words

A data compression or decompression method of the type applied to a system of data transmission by exchanging protocol data units between at least one transmitter terminal and at least one receiver terminal, each of said protocol data units comprising a header field and a data field, the compression method comprising the steps of: associating with a first sequence of N source protocol data units, a second sequence of M protocol data units to be transmitted, M being smaller than or equal to N; associating with at least certain data fields of said protocol data units to be transmitted, data that correspond to the compression of data contained in the data fields of at least two of said source protocol data units, the compression being according to at least one compression algorithm; associating with at least certain of said protocol units to be transmitted, reconstruction data that enables the reconstruction of said first sequence of source protocol data units from said second sequence of protocol data units to be transmitted; concatenating the compressed data and the reconstruction data to form a sequence of concatenated data; and slicing said sequence of concatenated data into data blocks, the data field of each of said protocol data units to be transmitted comprising at least one of said data blocks.

Claim 2

Dependent Claim 216 words

A data compression or decompression method of the type applied to a system of data transmission by exchanging protocol data units between at least one transmitter terminal and at least one receiver terminal, each of said protocol data units comprising a header field and a data field, the compression method comprising the steps of: associating with a first sequence of N source protocol data units, a second sequence of M protocol data units to be transmitted, M being smaller than or equal to N; associating with at least certain data fields of said protocol data units to be transmitted, data that correspond to the compression of data contained in the data fields of at least two of said source protocol data units, the compression being according to at least one compression algorithm; associating with at least certain of said protocol units to be transmitted, reconstruction data that enables the reconstruction of said first sequence of source protocol data units from said second sequence of protocol data units to be transmitted; concatenating the compressed data and the reconstruction data to form a sequence of concatenated data; and slicing said sequence of concatenated data into data blocks, the data field of each of said protocol data units to be transmitted comprising at least one of said data blocks.

Claim 3

Dependent Claim 131 words

Method according to claim 1, further comprising the steps of: receiving said first sequence of source protocol data units, data compression associating, with said protocol data units, a compressed data sub-field comprising data corresponding to the compression of the data of tile data field of said source protocol data units, generating data for the reconstruction of said source protocol units, concatenating said reconstruction data and said compressed data subfield in said sequence of concatenated data, slicing of said sequence of concatenated data into data blocks having a predetermined length chosen from a sub-set of at least one possible length, creating said second sequence of protocol data units to be transmitted, the data field of each of said protocol data units to be transmitted comprising at least one of said data blocks.

Claim 4

Dependent Claim 37 words

Method according to claim 2, wherein said generating step comprises a step of associating with each of said compressed data sub-fields, a sub-header comprising at least one information element representing the length of said compressed data sub-field.

Claim 5

Dependent Claim 28 words

Method according to claim 1, wherein said reconstruction data comprises at least one information element present in the header field of each of said source protocol data units.

Claim 6

Dependent Claim 50 words

Method according to claim 3, wherein said sub-header comprises at least one first byte bearing at least one information element present in the header field of the source protocol data unit corresponding to said sub-header, and at least one second byte bearing the length of the associated compressed data sub-field.

Claim 7

Dependent Claim 49 words

Method according to claim 2, wherein said generating step comprises a step of associating with each of said compressed data sub-fields, a sub-header comprising at least one designator designating the position of the end of said sub-field in the data field of the corresponding protocol unit to be transmitted.

Claim 8

Dependent Claim 25 words

Method according to claim 2, wherein said generating step comprises a step to generate a marker having a predetermined content, known to said receiver terminal.

Claim 9

Dependent Claim 36 words

Method according to claim 2, wherein the generating step comprises a step of associating a descriptor of the content of the data field of said protocol data unit with each protocol data unit to be transmitted.

Claim 10

Dependent Claim 40 words

Method according to claim 1, wherein said compression algorithm is an adaptive compression algorithm managing dictionaries of series of data at transmission and at reception, said dictionaries being updated identically at each transmission of one of said protocol data units.

Claim 11

Dependent Claim 52 words

Method according to claim 1, wherein said second associating step comprises the steps of: implementing a compression algorithm that associates a compressed data field with a source data field; comparing the length of said source data field and compressed data field, and selecting the shortest data field as a compressed data sub-field.

Claim 12

Dependent Claim 22 words

Method according to claim 3, wherein said sub-header comprises an information element representing the source data field or the compressed data field.

Claim 13

Dependent Claim 27 words

Method according to claim 1, wherein said protocol data units belong to the group consisting of data packets, frames of data, and transport layer protocol data units.

Claim 14

Dependent Claim 46 words

Method according to claim 2, wherein said protocol data units have a protocol data unit length chosen from a set of at least one possible length, and in that the length of said data blocks is a sub-multiple of said chosen length of protocol data units.

Claim 15

Dependent Claim 30 words

Method according to claim 1, further comprising a step of verifying that the receiver comprises means for carrying a decompression method corresponding to said compression method, before activating a compression.

Claim 16

Dependent Claim 26 words

Method according to claim 1, further comprising the step of providing a first time-delay before the creation of a non-full protocol data unit to be transmitted.

Claim 17

Dependent Claim 55 words

Method according to claim 15, further comprising the step of providing a second time-delay before the creation of a protocol data unit to be transmitted comprising at least one full data block of a predetermined length and no data block that is not full, the second time delay being smaller than the first time delay.

Claim 18

Dependent Claim 69 words

Method for the decompression of compressed protocol data units according to the method of claim 1, further comprising the steps of: searching for anti analyzing said data enabling the reconstruction of said first sequence of protocol data units, decompressing said data corresponding, in compressed form, to the data contained in the data fields of the source protocol data units; and restituting said first sequence of source protocol data units.

Claim 19

Dependent Claim 207 words

Data compression and/or decompression device, of the type applied to a system of data transmission by exchanging protocol data units between at least one transmitter terminal and at least one receiver terminal, each of said protocol data units comprising a header field and a data field, characterized in that it comprises compression means associating, in at least one direction of data transmission and for at least one communication, with a first sequence of N source protocol data units, a second sequence of M protocol data units to be transmitted, M being smaller than or equal to N, said compression means comprising: data compression means, according to at least one compression algorithm, providing for the compression of data contained in the data fields of at least two of said source protocol data units; means for generating reconstruction data that enable the reconstruction of said first sequence of source protocol data units from said second sequence of protocol data units to be transmitted; means for concatenating the compressed data and the reconstruction data to form a sequence of concatenated data, and for slicing said sequence of concatenated data into data blocks; and means for transmitting protocol data units to be transmitted comprising at least one of said data blocks.

Claim 20

Dependent Claim 207 words

Data compression and/or decompression device, of the type applied to a system of data transmission by exchanging protocol data units between at least one transmitter terminal and at least one receiver terminal, each of said protocol data units comprising a header field and a data field, characterized in that it comprises compression means associating, in at least one direction of data transmission and for at least one communication, with a first sequence of N source protocol data units, a second sequence of M protocol data units to be transmitted, M being smaller than or equal to N, said compression means comprising: data compression means, according to at least one compression algorithm, providing for the compression of data contained in the data fields of at least two of said source protocol data units; means for generating reconstruction data that enable the reconstruction of said first sequence of source protocol data units from said second sequence of protocol data units to be transmitted; means for concatenating the compressed data and the reconstruction data to form a sequence of concatenated data, and for slicing said sequence of concatenated data into data blocks; and means for transmitting protocol data units to be transmitted comprising at least one of said data blocks.

Claim 21

Dependent Claim 75 words

Device according to claim 18, further comprising means for decompression of data compressed by said compression means, said decompression means comprising: means for dividing said reconstruction data and said data blocks comprised in said protocol data units to be transmitted; decompression means symmetric to said data compression means, providing for decompressed source data; and means for reconstruction of said source protocol data units, from said decompressed source data, under the control of said reconstruction data.

Claim 22

Dependent Claim 38 words

Device according to claim 18, further comprising means of connection to at least one transmitter/receiver terminal behaving similarly to the data transmission system, and means of connection to said data transmission system behaving similarly to said transmitter/receiver terminal.

Claim 23

Dependent Claim 26 words

Device according to claim 18, wherein said device is integrated with one of said terminals or with an element of a communications network interconnecting said terminals.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-05-28	1999-11-27	2000-05-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-05-28	2003-11-27	2004-05-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-05-28	2007-11-27	2008-05-28	$7700.00	Window Closed / Lapsed

Method and device for the compression and decompression of data in a transmission system

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag