Telegraph

A telegraph was used to send telegrams. Around 1900, at Fang Rock, there was an example of an early Marconi wireless telegraph, able to "send messages a long way". (TV: Horror of Fang Rock, PROSE: Doctor Who and the Horror of Fang Rock)

The Doctor gave a space-time telegraph to the UNIT, to be used to summon him to Earth in the case of an emergency. (TV: The Day of the Doctor)