The government’s emergency alert should be tested every two years, a senior official has suggested.
A test alert was sent to every mobile phone in the UK, an estimated 60 million devices, on 23 April.
But MPs heard how five million users on the Three network did not receive the test alert.
Roger Hargreaves, director of Cobra, the government’s emergencies committee, said technical issues had been fixed so the system was ready for use.
Cobra, which is made up of a mixture of officials and ministers from relevant departments and agencies, deals with national emergencies including natural disasters and terrorist attacks.
April’s alert, which included a short message accompanied by a loud 10-second noise and vibration, marked the first UK-wide test of a new system to warn people about such incidents.
Mr Hargreaves, who works in the Cabinet Office, explained how the UK had been lagging behind most other countries who already used similar emergency alert systems “because no-one was willing to pay for it”.
Now the system has been built and tested, he told MPs on the Commons Public Administration and Constitutional Affairs Committee he believed it should be tested every couple of years to keep the technology operating smoothly.
“It’s international standard practice to do regular test messages,” he said. “I think there’s a case for doing it every two years but we haven’t got a ministerial decision on that.”
He added: “Other countries test not just their emergency alert but often also their sirens and broadcast systems… Some countries do it monthly.”
Many countries around the world use emergency-alert systems, including the United States, the Netherlands and Japan.
Following the test, Cabinet Office Minister Oliver Dowden said it was a “one-off” and he did not see the need for any further test “for the foreseeable future”.
However, he said it was likely there would be further public tests in the coming years.
Mr Hargreaves said the UK’s first test had been “massively successful” and was “far and away” the biggest public message ever sent out.
The Cabinet Office said the alert reached an estimated 93% of compatible devices in the UK.
However, MPs heard this fell slightly below target due to issues with one of the four major network providers in the UK.
The test message failed to get through to about five million mobiles on the Three network, which was significantly higher than those who had deliberately turned off functionality.
Mr Hargreaves said: “The big drop-off in available phones was because on one of the networks, Three, the message didn’t get through to all users.
“It went to about 10% of their users in England rather than all of them so that was the main driving factor in the numbers falling below the 95% plus that we had hoped for.”
Users could also opt out of the alert, while those whose phones were switched off or on aeroplane mode did not receive it.
Three “understood immediately that it had not worked and were hugely cooperative with us”, he said, adding that he believed the issues had now been resolved.
“We need to carry out some more tests but [Three] have done the work they needed to,” he said.
Mr Hargreaves also gave further detail about an error on the Welsh language test message, where the word for “safe” was autocorrected to the name of a Slovenian ski resort.
“When you put everything in to the system, if you don’t put a space after the last full stop and you press return, it autocorrects the last word,” he said.
“The key learning from that is to put a space after the full stop.”
Source : BBC