The Internet Engineering Task Force is working on extending the traditional TCP/IP model for supporting multimedia and real-time applications on the Internet. Thus, new protocols have been developed such as the Resource Reservation Protocol. With the rapid growth of mobile networks, the IETF is also working on creating and extending the existing protocols to support mobile users. This has led t...

In this work we describe a method to handle curved orbits in wavenumber domain focusing algorithm for high-resolution SAR data acquired by Low Earth Orbit satellites using spotlight mode. The standard wavenumber domain focusing algorithm make assumptions that start to be invalid when applied to high-resolution spotlight SAR data acquired in spaceborne low Earth orbit (LEO) configurations. The a...

Low earth orbit (LEO) satellite systems gained considerable interest towards the end of the previous decade by virtue of some of the appealing features that are endowed with, such as low propagation delay and the ability to communicate with handheld terminals. However, after the limited commercial success of the first networks of this kind, future satellite networks are now conceived as complem...

“Minimizing path delay” is one of the challenges in low Earth orbit (LEO) satellite network routing algorithms. Many authors focus on propagation delays with the distance vector but ignore the status information and processing delays of inter-satellite links. For this purpose, a new discrete-time traffic and topology adaptive routing (DT-TTAR) algorithm is proposed in this paper. This routing a...

Several low earth orbit (LEO) satellite constellations have been proposed for mobile satellite systems (MSS’s). Due to nonstationary coverage regions of individual LEO satellites, the offered traffic load for each cell varies continuously. The variation of the traffic load essentially requires dynamic channel assignment. Furthermore, extremely frequent handover requests require specific techniq...

In this paper we present and evaluate a hybrid-modular multiple access protocol for ATM transmission in a multiservice satellite system. Given appropriate synchronization and Doppler (shift) compensation, the protocol components can cope with the dynamics of the satellite constellation and are suitable to both mobile and fixed user environments. The general protocol framework is first given wit...

By nodal regression and apsidal precession, the Earth flattering at satellite low Earth orbits (LEO) is manifested. Nodal regression refers to the shift of the orbit’s line of nodes over time as Earth revolves around the Sun. Nodal regression is orbit feature utilized for circular orbits to be Sun synchronized. A sun-synchronized orbit lies in a plane that maintains a fixed angle with respect t...

satellite thermal control ensures safe operating temperature ranges for satellite components throughout the mission life. effects of altitude, spin, and position of satellite radiator(s) on the thermal control of a small low earth orbit (leo) satellite have been studied. results show that change in satellite altitude, in the range considered here, does not produce critical thermal conditions. h...

Linearization of the nonlinear equations and iterative solution is the most well-known scheme in many engineering problems. For geodetic applications of the LEO satellites, e.g. the Earth’s gravity field recovery, one needs to provide an initial guess of the satellite location or the so-called reference orbit. Numerical integration can be utilized for generating the reference orbit if a satelli...