The UKs four main mobile networks, along with one new player, have begun bidding for the latest slice of the airwaves, as the promise of 5G data and services is unlocked.

Bidding was initially expected to start several months ago, but has been held up by lengthy legal challenges from both EE and Three. The process itself is expected to last several weeks, and is overseen by Ofcom.

“Were pressing ahead with the auction to make these airwaves available as quickly as possible,” said Philip Marnick, spectrum group director at Ofcom in a statement last month. “This will benefit todays mobile users by providing more capacity for mobile broadband use. It will also pave the way for 5G, allowing operators to launch the next generation of mobile technology.”

5G is expected to vastly improve data speeds on smartphones and tablets, as well as freeing up a huge amount of bandwidth to help accelerate the Internet of Things revolution. It could also play a role in transforming the modern city, enabling innovations like driverless cars and IoT sensors embedded in everything from parking spaces to rubbish bins.

The first commercial 5G services are expected to launch in 2020, but trials are already underway in limited areas, as networks aim to establish the capabilities of this next generation. O2, Three, Vodafone and EE have all made bids for 5G spectrum, as well as Airspan Spectrum Holdings, a US-owned firm which also recently purchased a large chunk of Irish mobile spectrum.