
223Accurate and Reliable Simulation Framework for Mobile Computing Systems
(worldwide interoperability for microwave access) forum. This situation clearly raises the issue of
coexistence whenever the two types of services are collocated and no coordination agreement is
effected.
Until recently, frequency sharing between the xed/broadcasting satellite service (FSS/
BSS) and the xed service (FS) on a primary basis presented no serious restrictions because
xed terrestrial systems and satellite earth stations were small in number. The massive applica-
tion of FSS/BSS systems oriented to deliver broadcast or direct-to-user services via the very