LOS Range/ Coverage

Data Rate Depends on Distance With the constant power radiated and noise power, the received signal power decrease with distance. So does the signal-to- noise power ratio, and the data rate per hertz, according to Shannon’s Law. P T = 1W G T = G R = 1 F = 2.5 GHz Temp = Free space prop. (d -2 )

Line-Of-Sight (LOS) cell Line-of-sight h 2R R= (R+h) cos(  ) Arc AOC length = R*arccos(  ) R ~ 6374 km A B R R  O C

Line-Of-Sight communication range LOS area = = 2*Pi*R^2*[h/(R+h)] d = SQRT[(R+h)^2 - R^2] (R ~ 6374 km Shadowed area of the Earth’s surface Line-of-sight h LOS area d 2R A B

Potential coverage area increases with altitude... STRATO LEO MEO GEO

…but signal latency restrict interactive applications to low altitudes (terrestrial, stratospheric and LEO technologies) The time required for a signal to travel from one point on a network to another. STR LEO GEO MEO

Higher altitudes require more power... Reference: 10m S L M G

No. of stations to cover the Earth

Altitude of stations Terrestrial stations, alt. (1.5) m Stratospheric stations, alt km (airplanes, balloons) LEO - Low Earth Orbiting Satellites, alt ’500 km MEO - Medium Earth Orbiting Satellites, alt. 5’000-10’000km GEO - Geostationary Orbit Satellites, alt. ~36’000 km