FSO-Relevant New Measurement Results under ModerateContinental Fog Conditions at Graz and Milan

Interest in Free Space Optics (FSO) has gained enormous popularity over the last few years, mainly due to two reasons, firstly delivering data rates that can meet future broadband telecommunication requirements and secondly as an alternate technology to solve the last mile access gap. However, optical signal transmitted in free space is subjected to deterioration while propagating due to its interactions with the particles of different sizes and shapes. The presence of hydrometeors in the atmosphere, for example, fog, mist, clouds, sleet, rain, snow and hail presents a very severe challenge to the optical signal propagation; especially fog leads to signal attenuations up to an order of few hundreds of dB/km.