ATS at a controlled is provided by the control tower. Depending on the traffic levels, other ATS units such as Ground could be established as well. Take offs, landings and taxiing on the manoeuvring area are subject to ATC clearance. Vehicles on the manoeuvring area are also subject to ATC and are normally required to establish and maintain two-way radio communication.
The safe and orderly flow of traffic at a controlled aerodrome (and usually, its vicinity) is responsibility of the Tower controller.