Reduction of frames storage size in AFDX reception end-system using a lossless compression algorithm

Abstract

The growth of bandwidth needs and reliability requirements has determined Avionics Full-Duplex Switched Ethernet (AFDX) networks as the new generation of on-board communication mediums. AFDX belongs to the deterministic, real-time and Ethernet-based network family. The AFDX terminals are called End-Systems (ES). The frames arriving at an ES have to be stored in a reception buffer to avoid frames losses or corruptions due to slowdowns in the ES layers. Little attention is carried to the issue of buffer dimensioning which is generally set to a very large size. However, a too large buffer size leads to costs in terms of memory resources and energy. In this paper, we propose to reduce the reception buffer size by using an LZW-based compression algorithm implemented in hardware. To do that, we interpret frames as sequences of hexadecimal source symbols, and we use a set of 4 parallel dictionaries to encode sequences of source symbols in fix-length words. We realize compression gain measured on sets of frames comprising several millions of symbols, and we obtain until 22% of memory gain when the dictionaries sizes are optimally dimensioned.