| 摘要 |
PROBLEM TO BE SOLVED: To speed up the retrieval of a dictionary for data compression while suppressing the increase of storage capacity, by adding the information of links to the nodal points of plural levels to the respective nodal points of the dictionary and performing the retrieval of the dictionary while using the added link information as well. SOLUTION: A data line terminating device 21 is provided with a mutual connection circuit 24 with a data terminating device 22, a signal converting part 25 with a public telephone network 23, a control part 26 for internal control, an error correcting part 27 for error correction, and a data compressing part 28 for compressing/extending data. The data compressing part 28 is provided with a dictionary 29 in a tree structure, a dictionary retrieving means 30, and a link adding means 31. The information of links to the nodal points at plural levels is added to the respective nodal points of the dictionary 29, and the dictionary 29 is retrieved by the dictionary retrieving means 30 while using the added link information as well. When adding input data to the dictionary 29, the link adding means 31 adds the information of links to the nodal points at the plural levels within the predetermined range. |
