Earth-fixed cell beam management for satellite communication system using dielectic lens-focused scanning beam antennas

摘要: Earth-fixed cell beam management methods which may be employed to allocate beams generated by a constellation of low Earth orbit satellites (12) flying in orbits below geosynchronous altitudes are disclosed. These (19) electronically steered so that they illuminate "Earth-fixed cells" (26) as opposed "satellite-fixed cells." Beam steering apparatus using spherical dielectric lens (106) is In system employs satellite-fixed cells, the "footprint" propagated spacecraft defines zone on ground called "cell" illuminated spacecraft. This moves constantly around globe. sharp contrast, an cell" stationary region mapped onto surface (E) has permanent fixed boundaries, just like city or state. Although rapidly moving still shine their over footprints (16), locations at any given time do not determine location unchanging cells (26). The great advantage provided having boundaries grid (20) realized when subscriber being served one satellite must switch another same second because first out range local horizon. With this "hand-off" involves assignment terminal new communication channel within satellite. process takes and consumes processing capacity both It also subject blocking, call interruption, dropping if there idle next serving method avoids these problems allocating channels (frequency, code, and/or slot) basis rather than basis. Regardless satellite/beam currently particular cell, maintains assignment, thus ameliorating problem.