9 CLAIMS

• 1. A method for compressing streams of digital data, the data streams including successions of byte pairs in which a current byte immediately follows a prior byte, the data streams being generated by a data source for communication to a receiver, the method comprising:
• identifying a prior byte;
• identifying a current byte immediately following a prior byte;
• scanning a code word supply means for obtaining compression code words from a fixed table included in the code word supply means when a particular current byte immediately follows a particular prior byte, wherein the compression code words have respective lengths that are dependent upon the appearance of particular current bytes immediately following particular prior bytes, the codes words being generated with multiple codes, the multiple codes being determined by particular current bytes immediately following particular prior bytes, and having control parameters that may be adjusted so that the code word lengths are minimized where particular current bytes follow particular prior bytes, the compression code words provided in the table being created by analyzing byte streams of the data source produced prior to compression to develop occurrence frequency information concerning the appearance of current bytes immediately following prior bytes and providing code words at the code word supply means when the frequency of appearance of particular current bytes immediately following particular prior bytes, exceeds a predetermined value;
• determining whether a compression code word for the current byte can be obtained form the code word supply means; and
• communicating a compression code word for the current byte when the compression code word can be obtained from the code word supply means, and communicating an indication when a compression code word can not be obtained from the code word supply means when a particular current byte immediately follows a particular prior byte.
• 2. The method of claim 1 wherein the compression code words provided at the code word supply means are created using multiple start-step-stop codes, and wherein the indication communicated when a compression code word can note be obtained from the code word supply means when a particular current byte immediately follows a particular prior byte includes an escape code having a length dependent on the frequency with which a code word can not be obtained from the code word supply means when a particular current byte immediately follows a particular prior byte.
• 3. The method of claim 2 wherein communicated compression code words can be decompressed using a byte supply means that is responsive to the compression code words, such that given identification of the prior byte, and identification of the compression code word length and the start-step-stop code used to create the compression code word, the current byte can be decompressed.
• 4. The method of claim 3 wherein the byte supply means includes a fixed, look-up table prepared with occurrence frequency information concerning the appearance of current bytes immediately following prior bytes that is substantially the same as the occurrence frequency information concerning the appearance of current bytes immediately following prior bytes used for creating the compression code words.
• 5. The method of claim 4 wherein the method in used in an interactive informational and transactional network, including at least a host and a plurality of reception systems; wherein compression of the data streams is undertaken at the host and communicated to the reception systems where the compressed code words are reconstituted as an uncompressed byte streams.
• 6. The method of claim 5 where a first table of predetermined size optimized for compression speed is used to compress data at the host, and a second table of predetermined size smaller than the size of the first table optimized for accommodation by the reception system is used to reconstitute the compressed data.
• 7. The method of claim 6 wherein the byte stream is pre-compressed before the current byte is sought to be compressed with a compression code word obtained from the fixed table of the code word supply means.
• 8. The method of claim 7 wherein the byte steam is pre-compressed using run length encoding.
• 9. The method of claim 8 wherein the interactive service includes data for supporting interactive sessions and data for supporting messages and wherein the data for supporting the interactive sessions and the data for supporting messages are compressed.