(Reuters) - O2's 4G cellular network has been restored, the British mobile operator said on Friday, following a software glitch which caused smartphone users to lose internet access.
"A review will be carried out with Ericsson (BS:ERICAs) to understand fully what happened", said O2, which is owned by Spain's Telefonica (MC:TEF).
O2 and Softbank Group Corp's mobile phone unit, both software customers of Ericsson, reported disruptions to data services on Thursday that affected millions of customers.