 Satellite, buried fiber optic, and terrestrial microwave access have relegated commercial use of tropo-scatter to the history books.Because of high cost and complexity this mode is usually out of reach for the average amateur radio operator.F2 and TE band openings from other ionospheric reflection/refraction modes, or sky-wave propagation as it is known can also occasionally occur on the low band VHF frequencies of 6 or 4 meters, and very rarely on 2 meters (high band VHF) during extreme peaks in the 11 year sunspot cycle.