A subspace relay network or subspace communications network (short subspace com net) is a communications system used by many cultures for long-range data transfer.

The Federation operated such a network, stemming from the initial deployment of subspace amplifiers by the Earth Starfleet starship Enterprise. (ENT: "Silent Enemy"; TNG: "Aquiel")

In 2369, Commander Benjamin Sisko had a map of sector 22757 from the subspace com net displayed on his desktop monitor. (DS9: "Duet")

The Hirogen controlled a large network of similar stations, which stretched across the Delta Quadrant, and reached into Alpha and Beta Quadrants as well. (VOY: "Message in a Bottle", "Hunters")

Subspace communication
amplifier • antenna • bandwidth • beacon • hyper- • interference • interplexing beacon • link • log • message • monitor • neural transceiver • oscillation • relay • relay network • relay station • signal • transceiver • transmission • transmitter • transponder • wide-band