The connection to view is the term by which telecommunications means that the antennas of two radio systems are in optical range between them; in other words, to make a connection there must be no natural or artificial obstacles (hills, mountains, buildings) between the two antennas.
Transmissions from UHFs up to microwaves, in fact, have the property of requiring little power, but an indispensable condition for the connection is that there are no obstacles between the two radiant elements. An example is satellite broadcast at 11 GHz, which, with powers of some hundreds of watts, travel long distances. In the case of geostationary satellites (36,000 km), it is sufficient that there are strong perturbations, showers, snow, or, for example, in the case of GPS receivers, sufficient foliage is enough to attenuate or even prevent the radio signal from receiving stations earth.
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