Patent ID: 8214530

Claim:
A data collection system comprising a plurality of data compressing devices for compressing data, a plurality of data relaying devices for relaying the data, and a data collecting device for collecting the data: wherein the data relaying device comprises: a data analysis result synthesizing means for deriving a new data analysis result from a data analysis result being contained in received already compressed data; a data conversion information preparing means for generating new data conversion information indicative of a correspondence relation between a symbol and a new code responding to said new data analysis result; and a data converting means for converting the codes being contained in the already compressed data into the new codes being contained in said new data conversion information so as to recompress the data, and generating the already compressed data containing said new code, the new data conversion information, and the after-recompression code; and wherein the data relaying devices are arranged hierarchy by hierarchy responding to the number of hops or a round trip time up to the data collecting device so that the smaller the number of the hops or the round trip time of the relaying device up to the data collecting device is, the higher the hierarchy of the data relaying device becomes; wherein when recompressing the code being contained in the already compressed data, the data converting means converts the codes into the other codes based upon the data analysis result contained in the already compressed data so as to recompress the data without converting the code into the symbol and recompressing the symbol.