Vodafone has announced plans to switch off its ageing 3G network next year to focus on using the freed-up spectrum to expand its 4G and 5G networks. Here we explore what impact the move might have. What is 3G? Launched at the turn of the century, 3G spectrum heralded the start of the transition of the simple mobile phone to the bells-and-whistles smartphones most of the public own today. From video-calling and accessing services such as banking and online shopping to watching Premier League highlights, 3G spectrum ushered in the mobile enabled-era of the wider digital revolution. Mobile operators spent a staggering £22.5bn at the auction of the UK spectrum in 2000, as the promise of billions in new revenues from enhanced usage beyond texts and phone calls fuelled a furious bidding war. The Hutchison-owned Three launched the UK’s first 3G network in 2003. Why is it being switched off? The UK’s 3G networks were state of the art two decades ago, but the technology has been superseded by more powerful and efficient 4G and 5G networks. As most mobile phone users have upgraded to smartphones over the years, 3G is becoming obsolete. Today less than 4% of the data used by Vodafone customers is on its 3G network, and at BT-owned EE it is just 2%, compared with about 30% as recently as 2016. Mobile operators are seeking to retire 3G networks and use the spectrum to bolster 4G and 5G services. Who will be affected? BT, which owns mobile brands including EE and Plusnet, has previously said that there are between 2 million and 3 million people using 3G handsets across all UK mobile networks. Many of these are older phone owners who have preferred to stick with simple-to-use devices rather than be enticed by smartphones. Some have kept a 3G-enabled version as a fallback option in case they lose their main phone. In 2017, there was a resurgence in the popularity of simple phones, with Nokia’s 3310 3G selling 13m handsets worldwide and making it the UK’s third most popular phone brand that year. Will turning off 3G affect mobile phone coverage across the UK? Based on coverage data approximately 2.2% of the UK is only covered by a 3G signal. For the most part this in remote locations such as rural Scotland, parts of North Norfolk, Wales and Cornwall. However, all of these locations still have a basic 2G signal, which enables voice calling but has extremely limited access to internet data, which is not being switched off. However, EE has said it hopes that as coverage of 4G and 5G is rolled out it hopes to be able to switch off 2G networks as soon as 2025.