Development of Global Geographical Coverage Area for Terrestrial Networks Internetworked with Leo Satellite Network

V. O. C. Eke, A. N. Nzeako
2014 Communications and Network  
Network planning, analysis and design are an iterative process aimed at ensuring that a new network service meets the needs of subscribers and operators. During the initial start-up phase, coverage is the big issue and coverage in telecommunications systems is related to the service area where a bare minimum access in the wireless network is possible. In order to guarantee visibility of at least one satellite above a certain satellite elevation, more satellites are required in the constellation
more » ... to provide Global network services. Hence, the aim of this paper is to develop wide area network coverage for sparsely distributed earth stations in the world. A hybrid geometrical topology model using spherical co-ordinate framework was devised to provide wide area network coverage for sparsely distributed earth stations in the world. This topology model ensures Global satellite continuous network coverage for terrestrial networks. A computation of path lengths between any two satellites put in place to provide network services to selected cities in the world was carried out. A consideration of a suitable routing decision mechanism, routing protocols and algorithms were considered in the work while the shortest paths as well as the alternate paths between located nodes were computed. It was observed that a particular satellite with the central angle of 27˚ can provide services into the diameter of the instantaneous coverage distance of 4081.3 Km which is typical of wide area network coverage. This implies that link-state database routing scheme can be applied, continuous global geographical coverage with minimum span, minimum traffic pattern and latency are guaranteed. Traffic handover rerouting strategies need further research. Also, traffic engineering resources such as channel capacity and bandwidth utilization schemes need to be investigated. Satellite ATM network architecture will benefit and needs further study. for example, Iridium [7] and Teledesic, [8] projects. Irridium is a LEO satellite network, where connection oriented circuit-switched telephony service, and dial-up through satellite to ground Internet-gateway are offered on any spot on the earth. Irridium [9] uses polar orbits and 66 satellites forming a planned grid that covers the whole earth surface. It uses this variation of the Manhattan Network topology where satellites can rotate around the earth with equi-distance spacing between each two satellites on the same plane. In comparison, Teledesic, a connectionless network of satellites was initially planned with 840 LEO satellites [10], scaled down to 288 LEO satellites [9] before being scrapped off the drawing board in October, 2002 14 [11]. Teledesic can provide seamless compatibility with terrestrial broadband (fibre) networks. This network uses fast packet switching technology based on Asynchronous Transfer Mode (ATM) developments [9] . Two types of intersatellite links (ISLs) are often witnessed: Intra-plane ISLs, the ISLs between satellites on one orbital plane, and the interplane ISLs, the links between satellites on different planes. Both ISLs enable the communication between two users in different footprints with not more than two ground gateways being necessary. The interplane ISLs are permanently switched because of the fast change in relative positions of the satellite to each other. With the introduction of the advances in smart and adaptive radio [12], more possibilities for complex meshed ad hoc connectivity between any groups of satellites could be offered.
doi:10.4236/cn.2014.64025 fatcat:czkvjppdxbf6vjvplz46non5ru