Subspace relay network

A subspace relay network was collection of interlinked subspace relays allowing for communications across vast interstellar distances.

The Federation maintained a subspace relay network to facilitate interstellar communications. 

The Hirogen controlled a vast network that spread from the Delta Quadrant to the Alpha Quadrant. 

Lieutenant Terri Letac used the network to "ping" for the missing shuttlecraft, Brumby in early 2375.