This book of Proceedings contains papers of the "Third European Workshop on Mobile/Personal Satcoms" (EMPS '98), held in Venice, Italy, November 1998. For the third time, EMPS has given to the experts an opportunity for exchanging opinions and novel ideas in the exciting field of mobile and personal satellite communications. As with the 1996 edition, EMPS '98 issued a formal call for papers, gathering a large number of contributions from many different countries. Each submitted paper has been reviewed by international referees and, finally, selected by the Workshop Steering Committee (WSC). Furthermore, key-topics in the field of mobile/personal satcoms have also been focused on through a few invited papers. As EMPS has been conceived to gather trends and novelties in the field of mobile/personal satcoms, it is tightly matched to the natural evolution of the field itself. In this frame, the reader will notice how the dominant topics are related to system and network issues, while a very little number of contributions have been provided in the propagation and channel related areas. This represents a natural trend of a field, where deep efforts have been paid in the past years to understanding and modelling the physical layer and where the present interest is mostly migrating to the applications. Further changes and novelties may be envisaged in the future of this field. I believe that EMPS will continue to represent an effective opportunity to catch and understand more deeply this evolution.