A gateway is very similar to a repeater but instead of simply relaying the radio signal into the local area, a gateway converts the received audio signal into a data stream and sends it via the internet to another gateway where the data is converted back to audio for transmission at this new location.
Because gateways use FM the quality of the audio is very good and as the data is sent using the internet rather than radio there are no reception problems.
Gateways are mostly setup and operated by individual amateurs using their own equipment in their own homes using basic radios and a PC with an internet connection and the appropriate software, whereas repeaters are, because of their heavy duty use, normally often owned and operated by local radio clubs due to the higher running costs involved and the substantially higher grade of equipment used.
Prior to operating a gateway, an application must be made to OFCOM for an NOV to their licence.
An NOV is a Notice Of Variation. In simple terms, this can be considered an extension to the operators normal licence.
Internet gateways – a real life example
An example of a “radio <> internet <> radio” gateway system is Echolink.
Due to at least one end of the system will be transmitting actual radio signals on the amateur bands, only licensed amateurs may communicate via the system.
Therefore to use the Echolink system, the user has to be validated as a genuine amateur operator.
Because of the validation process involves inspection of the operators licence, it ensures that only people licensed to transmit can access the system.