Optimizations for efficient and transparent use of IP applications over HF links

This paper describes the architecture of an IP Gateway system implementing various enhancements to enable efficient and transparent use of standard multimedia and data IPv6 applications over strongly varying and bandwidth-limited wireless links such as HF radio. Three optimizations are proposed : (a) an HF-oriented Performance Enhancing Proxy (PEP) to improve the Quality of Service (QoS) of TCP/IP applications (b) Robust Header Compression (RoHC) of headers and (c) Joint Quality of Service and retransmissions management. Performance results obtained in real HF conditions are also presented in this article.