Low Earth Orbit (LEO) satellite constellations are foreseen as appropriate alternatives
to the geostationary satellite systems for providing global personal communications
services (PCS). Compared to geostationary satellites, these constellations offer a
significantly smaller round trip delay between earth and space segments. Furthermore,
the use of inter-satellite links (ISLs) has been identified as a means to provide global
connectivity in space, thereby enhancing system autonomy and flexibility, and has been
retained in the design of systems like Teledesic and SkyBridge. From a network point
of view, a major benefit of a ISL subnetwork in space lies in the possibility to transport
long distance traffic over reliable and high capacity connections, thus forming a good
base for ATM (asynchronous transfer mode) operation. With the development of the
third generation (3G) and fourth generation (4G) wireless networks, ATM is regarded
as one of the potential promising candidates for providing QoS guaranteed broadband
telecommunication services. It is possible to integrate the mobile satellite and A TM by
applying the inter/intra satellite links (ISLs) as the physical layer of WATM and considering a connection between two satellites as a virtual path connection (VPC) in
ATM
