Swedish Armed Forces Radio/Voice/Data Network, Serbia
The KV90 communication system was been deployed by the Swedish Armed Forces after the successful completion of evaluation and trials in Sweden. It was part of SWERAP, the Swedish Rapid Reaction Unit, which combined commercial and military systems for a shorter reaction time and a higher state of readiness.
Secure and immediate communications were essential in Kosovo. To make up the backbone of the system, the new tactical army communications system from Alcatel was linked with Ericsson's radio link-ups and Cisco's 3620 routers. To ensure consistent communications with the homebase, a satellite system was used with an HF system for backup. The long range HF radio voice and data network was designed by Marconi to help the Swedish rapid reaction force in Kosovo maintain communication with various long distance locations.
KV90 is the first HF system of its type to be deployed on active service and is used not only as a back-up medium, but also for welfare communications between soldiers in Kosovo and their families in Sweden.
The KV90 is the result of recent technological advances in HF modem design, Automatic Link Establishment (ALE) and frequency management, which have allowed automated HF systems to be built. The text and Email messages transmitted via the new HF system provide a cost-effective alternative to satellite communications.
Although currently deployed for military use, the Swedish authorities view KV90 not only as a multiservice system, but also for paramilitary and civilian services such as civil defence, emergency forces and diplomatic activities.
The Swedish forces saw benefits in designing one strategic HF communications system for both the Army and Navy. The system simplifies spares holding, maintenance, documentation and training. Moreover, during rapid deployment there may not always be an available satellite, meaning that with the KV90 the Army can control its own medium.
The evaluation and trials of the system lasted two years from 1998 to 2000.
PROJECT CHARACTERISTICS - SYNCHRONOUS HF RADIO
Marconi's system is characterised by its synchronous nature. One radio station is designated as "master" and the others synchronise to it, scanning on a common set of frequencies and listening on each frequency for a call request. As all the radio stations are scanning the same set of frequencies at the same time and the calling station knows what frequency the called station is listening on, link set-up is faster and on-air time shorter than for a conventional asynchronous HF radio scheme.
HF radio gives global coverage, with rapid deployment and interoperability between different forces at low cost. It is considered to be more robust, more readily available and harder to jam than available satellite technology.
In the majority of existing HF systems the participants in a communication net or link are assigned a common set of frequencies and the role of the automated system is to establish a useable link between participants on one of these frequencies. With asynchronous systems, radio receivers at different ends of the HF link scan round the common set of frequencies, stopping on each for a set period of time to determine if a link request is being made on that frequency. The different radios have no common knowledge of time, and hence scan round the frequency group asynchronously. Due to the asynchronous nature of these systems, the transmission time for the call request needs to be long enough to ensure that the called station has sufficient time to scan round all the frequencies in the scan group.
The faster link set-up and reduced on-air time means that the less time a user is transmitting, the less likely it is that a transmission will be detected or a position fixed. Managed synchronous HF technology also automates several aspects of the communication process, reducing the number and skill levels of radio operators that would be required to support a given size of network or a given volume of signals traffic.
Since the link set-up time is independent of the number of frequencies in the scan group, a greater number of frequencies can be included in the scan group. This provides higher protection and the ability to support increased traffic capacity through the use of multistation nodes.