Functional areas for advanced mobile satellite systems

In the third generation of mobile systems several satellite systems, each one tailored to specific user requirements, are expected to be integrated with the terrestrial cellular network. This paper deals with the extension to satellite systems of the advanced networking concepts which are emerging in the third generation framework. In particular, it focuses on the basic functional areas for mobile satellite systems, namely the cell and the location area. It is worth stressing that proper definitions of the satellite cell and satellite location area concepts, as well as an appropriate design of the satellite cell and satellite location area layouts, are essential, since the mobility procedures (cell reselection, paging, localization, handover) make systematic reference to these concepts. The topics exposed in this paper are applicable to any satellite system regardless of the orbit type (ranging from geostationary (GEO) to low Earth orbits (LEO)), the satellite spot-beam arrangement, the on-board switching capabilities (ranging from transparent payloads with reduced switching capabilities, to satellite systems provided with on-board processing capabilities (OBP) and inter-satellite link) and the access technique.