+1 Communications bonus.
"You're listening to Radio Troopers on 7.62, stay tuned to this frequency!"
Radio is an unlockable Equipment which can be used in one of three equipment slots available per trooper. Once acquired it boosts your Communications by +1, thus allowing your troops to receive orders in a way similar to a Comms. Officier. By comparison, a lowest ranked Comms. Officer (level 6) provides +5 .
Note that some of the high-level orders cannot be used because of limited Communications. If an army that has a trooper with Radio does not have a Comms. Officier., the only commands that will be available will be "Solo Mission" and because those two are the only commands that require only 1 Communications point.