|
|
As mobile service demands increase dramatically,
interest in cellular system structure with hierarchical
terrestrial/satellite architecture has emerged. Without satellite
participation, terrestrial cellular systems would be primarily
restricted to regional service. For the network to have seamless
radio coverage and sufficient capacity to accommodate anticipated
high teletraffic demand, integration of satellite network and
terrestrial cellular system is indispensable. In this research
project, a space/terrestrial mobile radio communication network
with multiple hierarchical cellular overlays is considered. In
the lowest hierarchical level, microcells serve the highest
teletraffic density, while overlaying macrocells serve both calls
from areas that are difficult to be covered by microcells, as
well as overflow traffic from microcells. At the highest
hierarchical level, satellites focus their spotbeams to serve
satellite-only users sparsely distributed and act as teletraffic
relief for the terrestrial segment.
|