language: en

Higher Bandwidth X

John Danskin *
Princeton University Computer Science Department
Princeton NJ, 08540
jmd@cs.princeton.edu

Abstract Network bandwidth has always been a key issue for multimedia protocols. Many potential users of networked multimedia protocols will continue to have low bandwidth network connections for some time: copper wire ISDN, infra-red, cellular modems, etc.. Compression provides potential relief for users of slow networks by increasing effective bandwidth. HBX introduces a new technique, based on arithmetic coding and statistical modeling, for compressing structured data. Applied to the X networked graphics protocol, this technique yields 4.5:1 compression across a representative set of traces, performing twice as well as the popular LZW-based Xremote compression protocol. HBX's coding techniques are generally applicable to the graphics and imaging subset of multimedia protocols. Future work will determine whether HBX's coding techniques can be applied to audio and video streams as well.

1 Introduction