Hop (telecommunications)

In telecommunication, the term hop has the following meanings:

The excursion of a radio wave from the Earth to the ionosphere and back to the Earth. The number of hops indicates the number of reflections from the ionosphere.
A similar excursion from an earth station to a communications satellite to another station, counted similarly except that if the return trip is not by satellite, then it's only a half hop.
A waveform transmitted for the duration of each relocation of the carrier frequency of a Frequency-hopping spread spectrum system.
To modify a modulated waveform with constant center frequency so that it frequency hops.
With routing a distance in terms of topology and of a length that may be not specified topographically, i.e. one hop is the step from one router to the next, on the path of a packet on any communications network (on the Internet often discovered with pings or traceroutes). The hop count then is the number of subsequent steps along the path from source to sink.