The UK's communications regulator has launched an investigation into mobile network EE after an outage earlier this year may have left some customers unable to access the emergency services.
An EE spokesperson told The Reg: "It is in no way related to the 5G switchover at all."
The regulator said in a statement yesterday: "Ofcom has decided to open an investigation into whether BT [EE's owner] has complied with its obligations under section 105A(4) of the Communications Act 2003 (the Act) and the General Conditions A3.2(b), A3.5 and A3.6."
Under the Act, providers are required to "take all appropriate steps to protect, so far as possible, the availability of the provider's public electronic communications network".
As such, Ofcom noted they must "make accurate and reliable Caller Location Information available to the Emergency Organisations handling the calls to '112' and '999'."
The comms watchdog added that "opening an investigation does not imply that we have yet formed any view about whether or not the company has breached any regulatory or legal provisions. We aim to complete the evidence gathering phase of the investigation by December 2019."
An EE spokeswoman said: "We're fully cooperating with Ofcom in its investigation after an issue on our network affected calls made over 4G on May 21st 2019. This was due to a technical error that was corrected and restored as quickly as possible.
"We've already taken proactive steps to update our processes based on lessons learnt to help prevent this from happening again, and apologise again to our customers for the inconvenience this issue caused."
EE is also in the process of replacing the Airwave radio service with a £1.2bn 4G Emergency Services Network (ESN), turning off the previous network by 31 December 2019.
Last month the Home Office added two years to its contract with EE for the company's role in implementing the ESN.
The tender notice said the deal will run until December 2024 due to extra time needed to roll out mobile coverage, radio equipment, technical interfaces, management capabilities, critical mobile communications and support services.
The National Audit Office also recently warned that the project is likely to be three years late and £3bn over budget. ®