Improved quality of service in ionospheric telecommunication systems planning and operation: Cost 251 Major Achievements.

COST Acrion 251 <ImprovedQuality of Service in lonospheric Telecommunication Systems Planning and Operation) has been a dynamic group of 122paruicipanisfrom 46 organisations in 20 Nations working as a iechnical connnunity towards a common goal. The main objectives were lo colleci additional quantities and types of ionospheric dala, Logenerale procedures for prediction of ionospheric modeis over Europe and to promote tbeir use, lo extend ubeexisting modeis lo give system performance statistics and lo develop a melhodology for channel simulalion. The major achievemenis include especially te productionof databases of ionosphericrneasuremenls,ubedevelopment of procedures for ionospheric and plasmaspheric modeUing, mapping and forecasting and modeis for users for overali performance prediction of systems in Europe. The resulis obtnined ja te frame of COSTAction 251 during te period 1995-1999 are summarised with particular reference lo their applicalion for terrestrial and Earthspace ionospheric telecommunication systems planning and operation. Reconunendations for future activities are presenled. Kcy words: Ionosphere, Modelling, Mapping, Prediction, Forecasting, Radio Waves, Radio Communications.