Subspace relay
A subspace relay was a subspace device designed to receive and re-transmit subspace communications signals to other relays in a larger subspace communications network. Subspace relays might be installed in starships, on planetary surfaces, or on dedicated subspace relay stations. (; )

Organizations and species including the Cardassians, the Dominion, the Hirogen, and the Federation used subspace relays as part of networks for communication purposes. (; ,  okudagram)

Federation starships, themselves equipped with subspace transmitters, relied on a network of subspace relays to boost inter-starship communication over the vast distances of interstellar space. ()

In 2369, the Bajoran engineer Neela activated a short range subspace relay she had previously placed in the security office aboard Deep Space 9. Combined with her creation, the program ANA, this was designed to help her escape after she assassinated Vedek Bareil Antos after deactivating the Promenade's weapon detectors. ()

In the 2370s, the Dominion had an unmanned subspace relay on Callinon VII which the Karemma were told by the Vorta to send messages to. The  transported Jadzia Dax and Miles O'Brien to the subspace relay in 2371 to see where the messages were relayed to. They were detected and a shield was activated around the relay. ()

In 2374, when the  was lost in the Delta Quadrant, they encountered a network of Hirogen subspace relays which were 100,000 years old and extended to within communication range of the Alpha Quadrant. The relays were powered by artificial quantum singularities, similar to Romulan warp drives. Each of these relays produced an intense gravitational field. Voyager destroyed one of the relays and the energy from the quantum singularity created a massive discharge that disabled the stations on the relay network. ()

Following The Burn in the 31st century, a number of the Federation's subspace relays fell into disrepair and were destroyed. Their loss limited the Federation's and Starfleet's attempts to communicate and reconnect with members. ()

de:Subraumrelais
relay
Communications technology