Ultraviolet scattering communication channels

Tropospheric molecular and particle scattering in ultraviolet (UV) scattering wave-lengths enable non-line-of-sight (NLOS) communication which brings robustness to blockage or shadowing. NLOS communication is particularly desirable to relax or eliminate pointing, acqui-sition and tracking requirements. NLOS-UV links can be used as an alternative to outdoor infra-red or visible light links or in combination with existing optical or radiofrequency wireless links. Analytical, experimental and numerical approaches have been used to determine the NLOS-UV channel impulse response and path loss. These studies demonstrate that UV channel is of multi-path nature due to the volumetric scattering due to air molecules, aerosols and hydrometeors. Be-sides intersymbol interference and bandwidth limitation resulting from frequency-dispersive na-ture of NLOS-UV channel, performances may be also degraded by high path losses and turbulence-induced fading as the link range increases. This chapter provides an overview of lat-est advances in NLOS-UV channel modeling and results.