This book is both a survey of practical concepts for forecasting the performance of various telecommunication systems as well as a balanced treatment of space-weather phenomena that give rise to telecommunication impairment episodes. It bridges the gap in the relationship that exists between the following two disciplines: space weather and telecommunication system performance. There are a number of books that address one of the two disciplines in some detail, but only merely mention the other as an afterthought. In this book the author has married the two disciplines so that the readership can see the connections more clearly. All professional and academic researchers in the fields of telecommunication science and technology; military and civilian telecommunication; applied aeronomy and ionospheric physics; and space-weather will find this book essential. It will also be of interest to professionals and researchers in the fields of solar and magnetospheric physics. Ch. 1: Introduction Ch. 2: The Origins Of Space Weather Ch. 3: The Ionosphere Ch. 4: Telecommunication Systems Ch. 5: Prediction Services and Systems Ch. 6: Research Activities and Programs Ch. 7: Epilogue