Every area of airspace has certain frequencies that the Air Traffic Controller’s (ATC) operate on, each divided into sections that each Controller operates in. The hierarchy of the ATC service is as follows : Ground\Clearance\ Delivery, Tower, Departure\ Radar\ Approach. In real life, a large airport may use many frequencies and also have people operating them which may differ from the multi-player sessions you may encounter in FSX as there is not near as many people to work all the services that are needed. You may therefore experience, when being the only ATC online, that you will need to cover all the positions of the hierarchy. Every frequency is listed on navigational charts and/or information sheets which are easy to find on the Internet for everyone to use. The frequencies are also listed within the standard FSX GPS. When a controller is logged on and at an aerodrome, the location and frequency will show in the Multi-player Chat Window. The airspace is marked by several boundaries, here are some examples of what you can expect to encounter. Also, because from time to time there may only be one or two controllers online at on point, we cannot divide the airspace as you would do in a ordinary ATC environment. This means that if comfortable in doing so, the controller may have to cover more than one position. As you can see on the map (taken from Avinors archives), the airspace is divided into sections, the closest one to the tower is controlled by a Tower Controller. The part around outside that area is controlled by approach\departure and the space outside and between airports these areas is done by a radar controller. When you are acting as an lone ATC in a session, you may be contacted by pilots from a fair distance away. If you are not sure of the procedures in which to control, ask the pilot to call you back when he/she is closer to your position’s airspace.
For any questions on airspace, feel free to ask any of our approved controllers and/or mentors.