Holotransmitter

Nute Gunray and Darth Sidious use a holotransceiver to communicate. A holotransmitter, also known as a holotransceiver, served as a device that could both intercept and project holographic communications, enabling communication between individuals across great distances. A device of this type was built into the mechno-chair used by Nute Gunray.

Back in 3951 BBY, miners who were trapped at the Peragus Mining Facility, made alterations to a holo-transmitter, turning it into a makeshift relay. This relay broadcasted quick transmissions, formatted as a Military flash code, from the confines of the mining facility. However, the signal was not very powerful, leading the miners to believe that even if it made it past the asteroid field around the facility, any potential rescuers would need to be actively monitoring those frequencies to even pick it up.