A subspace relay is a 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 use subspace relays as part of networks for communication purposes.
Signals sent travel faster-than-light (FTL), making communication over vast distances possible. Without a subspace relay network, transmissions would take place at light-speed, taking years to reach even neighbouring star systems. Starships, themselves equipped with subspace transmitters, also rely networks of subspace relays to boost inter-starship communication over the vast distances of interstellar space.