Project status and system architecture of an automated HF system to be used by the Swedish Armed Forces

A program for procuring an automated HF system to be used by several services within the Swedish Armed Forces has been ongoing for several years under the project name KV 90. Interoperability and mobility are some of the key features, which have become much more important and even essential in order to be able to participate in international peacekeeping operations and relief operations during disasters and emergencies (e.g. earthquakes). Integration in the tactical digitized battlefield is another issue of high importance. Utilization of the adaptive features embedded in the automated HF system whilst still maintaining the required security level is a strict requirement. The ability to use the automated HF system in nodes ranging from a small mobile station up to trunked multi-station nodes (such as a coastal radio station) calls for a flexible and modular system architecture, which is described in detail. It has become apparent that if the HF network shall be utilized to its maximum potential it is essential that it be not installed and viewed upon as a reserve resource needing operator intervention when other communication networks fail. Instead the HF system needs to be integrated seamlessly into the IP based infrastructure, thus carrying information adaptively and sometimes simultaneously with other communication networks. It is evident that a low-capacity network cannot carry the traffic load normally requiring a high-capacity network without some limitations focusing on minimizing the traffic load over the bottleneck channel. The use of proxies is one way. Information content filtering and decrease in database repetition rate are other methods, and they are probably all needed. A completely different project that faces similar problems as "IP over HF" is the development of an interplanetary Internet, and an overview of the approach being taken within that project is given.