Mobile P‐service satellite system comparison

Abstract

Several future operators of the mobile handheld telephone (P‐service) satellite communications systems are gearing up for system implementation to compete for the mobile handheld telephone market of the future. While these companies are proceeding with system realization, they are also looking for partners to finance these huge satellite projects. Potential partners or bulk users are administrations of national communication systems and operators of national communication satellites. These future partners ask themselves which P‐service satellite communication system they should choose. There is not an easy answer because P‐service satellite systems come in many varieties. There are the low altitude earth orbiting satellites (LEOs), the medium altitude earth orbiting satellites (MEOs), and the geosynchronous altitude earth orbiting satellites (GEOs). Each system has a different type of satellite repeater: digital regenerative, transparent digital, and the bent‐pipe. And each satellite system uses its own modulation/multiple access system. The fact that satellites circle the earth at different altitudes has an impact on speech quality, and, because systems vary in satellite as well as constellation complexity, there are different price tags attached. All systems display ingenious features and will eventually work. Mobile users will decide which system will best serve their purposes. This article attempts to compare six P‐service satellite systems and find a method for system selection. By use of self‐established system criteria, it is possible to arrive at a P‐service system selection. By weighing the system criteria, the sensitivity of system selection can be tested. The results or the selection of a particular system should not be considered a recommendation; rather, the process of selection should be used as a possible guideline.

Tri‐orthogonal polarization diversity reception for non‐geosynchronous satellite orbit ionospheric channels

“…Three distinct non‐geosynchronous satellite systems are analyzed, all transmitting an RHCP signal; the LEO Iridium satellite system , the LEO Orbcomm Telemetry, Tracking, and Command (TT&C) system and the GPS system , operating in a mid‐Earth‐orbit.…”

Performance analysis for a guaranteed handover service in an LEO constellation with a "satellite-fixed cell" system

“…Therefore, the maximum size of the queue of the channel-locking requests in a cell is equal to or lower than Once a call experiences a handover from the source cell to the first transit cell at time (random handover), the subsequent handover from cell to cell with , should it occur, will be at time (periodic handover). 3 At time , all calls in cell at the time of the previous handover from cell to cell , have left cell…”

“…This paper is concerned with the satellite component of the future UMTS that will be based partly or totally on non-GEOstationary (non-GEO) constellations of satellites [i.e., low earth orbit (LEO) and medium earth orbit (MEO)] [2]. Given the allocated bandwidth, the capacity of the network can be increased through frequency reuse not only among satellite footprints ( satellite coverage areas), but also within the footprints themselves [3]. This is achieved by dividing the footprint into cells, each one corresponding to a specific beam of the satellite antenna radiation pattern.…”

Joint spectrum and power optimization in the design of the UMTS satellite component

“…In that case, the focus is moving from e$ciency towards power. Power constraints often limit the maximum number of users per satellite more than the bandwidth limitation [15]. In order to maximize the number of users, thus, lowering the channel operation cost, spectral e$ciency could be somewhat relaxed to maximize power e$ciency.…”