The radio transmitter can be tuned to the selected frequency manually by its user. In half-duplex communication, each party can communicate to the other, but not simultaneously; the communication has one direction at a time : ATC to pilot(s), or Pilot to ATC.
The frequency band definition:
|Frequency band||ITU designation||ITU abbreviation|
|30–300 kHz||Low frequency||LF|
|300 kHz – 3 MHz||Medium frequency||MF|
|3–30 MHz||High frequency||HF|
|30–300 MHz||Very high frequency||VHF|
|300 MHz – 3 GHz||Ultra high frequency||UHF|
|3–30 GHz||Super high frequency||SHF|
In the real world
On oceanic flight, with the long distance involved between ATC and pilots, the High frequency (HF) communication band is selected by using the long range communication property of this frequency.
Example of a VHF/HF communication panel in a 737 aircraft:
The "standard" spacing used to be 25KHz or 0.025 MHz between each channel.
118.000 / 118.025 / 118.050 / 118.075 / 118.100 / 118.125 / 118.150 / 118.175 / 118.200
With traffic increasing, it was necessary to create more channels. It was impossible to assign lower channels, as VOR & ILS uses frequencies from 108.00 to 117.95 MHz. Also it was impossible to assign higher channels, as they are used for satellite communications and military operations.
The solution was to reduce channel spacing from 25MHz to 8.33MHz. Hence, within each 25KHz channel we can have three 8.33KHz channels (25/3=8.33).
Therefore, with 8.33KHz spacing within each channel it gives the following table :
|Displayed frequency||Real frequency||Frequency spacing|
You may have noticed that frequencies 118.000 and 118.005 use the same real frequency but with a different spacing. If you select on your 8.33 radio frequency 118.000, it will automatically operate as an old 25KHz radio. Now, if you select 118.005 it will operate in 8.33 mode. Only 8.33 receivers tuned on 118.005 will be able to hear you.
In your cockpit, you must setup only the first 2 digits after the decimal and the 3rd digit is automatically tuned by the system to either a 0 or 5.
As the IVAO pilot software interface is compatible with 8.33kHz, please add the letter Y to the equipment in your flight plan.
In IVAO network
- The use of aeronautic radio transmitters is reserved for real world flights.
- It is forbidden to use them for any IVAO activities.
- TeamSpeak 2 software for communication using voice
- IVAO pilot client interface and ATC client interface for communication using text and to obtain ATIS information, METAR, TAF …
In order to make communications more realistic, you can choose the VHF frequency in your cockpit or IVAO Pilot Client interface and the software will do the rest to connect you to the correct channel.
The IVAO Pilot Client interface is an IVAO tool which synchronizes the pilot frequency in the cockpit and the interface with the air traffic controller TeamSpeak channel (if existing). An air traffic controller in IVAO is responsible to tune the frequency of his position in the IVAO ATC software radar software, to create a channel in the selected TeamSpeak server, and to complete his ATIS accordingly in order to perform voice control sessions.
Use of frequency in IVAO for air traffic controller
This frequency can be taken from:
- The IVAO database (HQ database or your division database)
- Real charts if the database was not updated
How to tune the frequency in ATC Client?
- Click on the COM1 tab in the IVAO ATC software COMMbox window
- Type double bars // followed by the VHF frequency wanted
How to tune TeamSpeak for voice communication?
What happens when you open an active position as an air traffic controller?
- When connecting to the IVAO network (which is called IVAN) with IVAO ATC software, you must choose a network server and a TeamSpeak server.
- Your position is identified by using the ICAO code of your control zone or airfield - for example: ICAO_POS.
- The VHF frequency is tuned on IVAO ATC software and sent via IVAO ATC software to the IVAN network to associate your position with the frequency.
- On TeamSpeak you are connected as - for example: ICAO_POS
- Now create your unique channel on TeamSpeak using your position - for example: ICAO_POS (since two different positions can share the same frequency, you cannot use the frequency in the channel name).
- The link between the position and the frequency is created by the ATIS of the position and it is broadcasted in the IVAN network.
- When a pilot wants to connect to an air traffic controller, and after tuning to the correct frequency, he receives the ATIS information automatically in the IVAO pilot software interface and IVAO pilot software then tunes TeamSpeak to the correct IVAO ATC channel using the position ICAO_POS.
Use of frequency in IVAO for pilots
This frequency can only be used utilising text for technical and practical reasons.
Any air traffic controller requires 2 way radio communication contact prior to any movement:
- If an Air Traffic Controller is available, set the VHF frequency on the IVAO pilot software as the active frequency. You will receive the ATIS information by text and TeamSpeak will automatically connect to this channel (except if you have deactivated voice mode or the air traffic controller is in text only mode).
- If there are no air traffic controllers in your area, you must remain on the Unicom frequency 122.800MHz and perform self-announcement text messages using the scratchpad in the IVAO pilot software interface.
- VID 150259 - Creation - Wiki integration
- VID 450012 - Update April 2020
DATE OF SUBMISSION
- 01:59, 23 February 2021
- This documentation is copyrighted as part of the intellectual property of the International Virtual Aviation Organisation.
- The content of this documentation is intended for aviation simulation only and must not be used for real aviation operations.