Communications range
Communications range, also known as communication range, comm range, or, likewise, hailing range was the range or soonest distance at which a hail or similar form of contact could be made or received. 

When Captain Kathryn Janeway and Commander Chakotay were left on the planet they named New Earth, they kept in touch with  as long as they remained in communication range, which lasted for a period of roughly twenty four days. Upon Voyagers return to the planet, contact was made when the ship was still 30 hours away, while traveling at warp 6. ()

For the Silver Blood copy of Voyager, hailing range on subspace radio was at least twenty two light years, even with a malfuncting subspace transceiver, however, with only one active comm circuit, said task could not be achived while at warp. When this situation was encountered during its attempt to contact the real Voyager, they were unable to communicate on conventional radio until they were in hailing range, which, at their then-unspecified speed, was still five minutes, thirty-four seconds away while at a distance exceeding five million kilometers. ()

Measurements
Communications technology