Data compression on a data connection
First Claim
1. A method for compressing and transmitting data on a connection between two parties in a telecommunication system comprising at least one slow transmission channel (Um), the method comprising:
- assembling the data to be transmitted into frames (F) which contain at least a header section (1) and a data section (2), and compressing at least one section (1, 2) of at least some of the frames (F) prior to transmission, making at least two different compression algorithms available to the transmitting party, making at least two different decompression algorithms available to the receiving party, characterized in that the transmitting party;
compresses at least one section (1, 2) of at least some of the frames (F) with at least two different compression algorithms;
selects the compression algorithm that yielded the best compression ratio; and
transmits the frame (F) over the slow transmission channel (Um) to the receiving party, compressed with said selected compression algorithm.
2 Assignments
0 Petitions
Accused Products
Abstract
The invention relates to compressing and transmitting data on a connection between two parties in a telecommunication system comprising at least one slow transmission channel, such as the air interface Um of the radio network. The data to be transmitted are assembled into frames (F) comprising a header section (1) and a data section (2). Prior to transmission, at least the header (1) or the data section (2) of at least some of the frames (F) are compressed. The transmitting party has available at least two different compression algorithms and the receiving party has available at least two different decompression algorithms. The transmitting party compresses at least one section (1, 2) of at least some of the frames (F) with at least two different algorithms, and transmits the frame (F) compressed with the algorithm that produced the best compression ratio.
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Citations
17 Claims
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1. A method for compressing and transmitting data on a connection between two parties in a telecommunication system comprising at least one slow transmission channel (Um), the method comprising:
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assembling the data to be transmitted into frames (F) which contain at least a header section (1) and a data section (2), and compressing at least one section (1, 2) of at least some of the frames (F) prior to transmission, making at least two different compression algorithms available to the transmitting party, making at least two different decompression algorithms available to the receiving party, characterized in that the transmitting party;
compresses at least one section (1, 2) of at least some of the frames (F) with at least two different compression algorithms;
selects the compression algorithm that yielded the best compression ratio; and
transmits the frame (F) over the slow transmission channel (Um) to the receiving party, compressed with said selected compression algorithm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
compressing the header sections (1) of the frames (F) with an algorithm which is substantially the same between two successive frames (F), and compressing the data sections (2) of the frames (F) with at least two different algorithms of which the one is selected that yields the best compression result. -
12. A method as claimed in claim 1, characterized by transmitting, with each compressed frame (F), an identifier indicative of the compression algorithm used.
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13. A method as claimed in claim 1, characterized in that when the compression algorithm changes the transmitting party separately transmits information on the change to the receiving party.
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14. A method as claimed in claim 1, characterized by
compressing a frame (F), which is advantageously the first one representing a specific type of data, with substantially all the algorithms known to both parties, compressing the subsequent frames (F) first with the algorithm that at the previous frame (F) produced the best result, discontinuing to carry out the other algorithms if the length of the frame (F) compressed with the algorithm in question exceeds the length of the frame (F) compressed with up to that point the best algorithm. -
15. A method as claimed in claim 1, characterized by the transmitting party being assigned a restricted time for the compression, such as the time between two successive transmit turns in time division multiple access systems.
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16. A method as claimed in claim 15, characterized in that at the end of the restricted time the transmitting party discontinues testing the compression algorithms and transmits the frame (F) compressed with the algorithm that up to that point has yielded the best compression result.
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17. A method as claimed in claim 16, characterized by
maintaining, for the different compression algorithms, a parameter indicating efficiency, advantageously a sliding average of the compression ratio, compressing each frame (F) or a section (1, 2) thereof with a few, advantageously 1-3 of the best compression algorithms up to that point, in an order determined by the parameter indicating efficiency, and testing, in the remaining part of the restricted time, the remaining algorithms alternately so that at successive frames (F) different algorithms are tested.
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Specification