Subspace amplifier

From Memory Alpha, the free Star Trek reference

A subspace amplifier is a communications array designed to allow real-time subspace communication.

A series of subspace amplifiers were deployed by the Earth starship Enterprise during its initial exploratory mission. The amplifiers were deployed to allow better communication with Earth and United Earth Starfleet Command. The amplifiers were designation by letter-number combinations. The first such device, Echo One, was deployed in July of 2151, with Echo Two being deployed two months later. (ENT: "Fortunate Son")

In September of 2151, an alien vessel destroyed both Echo One and Two during a sustained attack on Enterprise. Following the successful elimination of the alien threat, a third amplifier was dropped, to replace the lost two. (ENT: "Silent Enemy")

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