O2 have launched WiFi & 4G Calling on the iPhone 7 & 7 Plus.
WiFi and 4G Calling will allow customers to make and receive calls over WiFi even if they can’t connect to the mobile network and be able to enjoy clearer calls with 4G Calling, both at no extra charge.
Customers will be able to make and take calls on the London Underground using WiFi.
Calls on 4G should sound much better than standard 2G. WiFi Calling will be available anywhere in the UK, 4G Calling will initially be available in London, Leeds and Slough but will be rolled out nationally by end of Q3.