Cube Interactive Limited has been handed a spectrum licence for the city of Cardiff.
Communications watchdog Ofcom announced the move, which will leave Cube free to provide mobile broadband services with its 8MHz.
The chunk of interleaved spectrum means besides providing 3G services, Cube could also supply mobile TV services, as well as a digital terrestrial service similar to Manchester's Channel M.
"Ofcom awards spectrum licences that are technology- and service- neutral and tradable. This allows users to decide how they should be used and means that there is flexibility for use to change in the future," the industry watchdog said in a statement.
Ahead of the digital switch, Ofcom plans to offer similar spectrum awards in other cities around the UK, subject to demand.