A Vulcan band frequency was a type of communications frequency employed by the Vulcans during the 24th century.
In 2369, the science vessel T'Vran contacted the Starfleet runabout USS Ganges in the Gamma Quadrant on a Vulcan band frequency asking if Odo, Croden and Yareth needed assistance after their turbulent encounter with Ah-Kel in the Chamra Vortex. (DS9: "Vortex")