According to real time outage monitor, Down Detector, issues were being reported as early as 9:14am GMT, with networks including Vodafone, O2, 3, Virgin, Vodafone, Tesco, GiffGaff and EE, all being affected.
“Mobile network downtime can be caused by a vast surge in the number of simultaneous connections can overwhelm the capacity of a particular cell or even a cluster of cells in a particular location," said Alan Stewart-Brown, VP of EMEA, Opengear.
"Each cell is typically designed to handle a predetermined number of concurrent connections, all of whom share that specific cells connection capacity and data bandwidth. In normal circumstances this capacity can account for large peaks in usage, but these are definitely not normal times.”
In response O2 released a statement saying that it was aware of that some users were having problems connecting to its void network and was investigating the cause. Services affected include 2G, 3G and 4G networks but its mobile data and messaging services and O2 Wifi are not affected. The company is updating its network status here.
EE shifted the blame, however, in a statement to Metro, an EE spokesperson said the company believes it to be an issue with the O2 network, saying their customers were only having trouble making calls to O2 phones.
A spokesperson at Three said: "We are aware of an issue affecting around 3% of voice calls. We apologise for any inconvenience and our team is working to fix this ASAP. The rest of the network is stable."
While Vodafone told the BBC, “there was a relatively short-lived problem with around 9% of voice calls only on 3G not getting through. All the operators are working together on the matter”.
On the part of GiffGaff, it has a rolling updates board with the last update as of 10:06am GMT this morning saying that it is experiencing intermittent issues with its nationwide voice services.
This means that users may not “be able to hear the person you’re calling or they might not be able to hear you, and in some cases your calls may not connect” but that it was “investigating this as a priority”.
The news follows the announcement made by Prime Minister Boris Johnson who advised people to work from home if they could, as well as to avoid pubs, bars and theatres.
"I don’t believe that the UK networks are ill-prepared, but despite lots of contingency planning and scenario modelling, the UK has never seen this level of instant and sustained demand before. Most carriers have the ability to adjust their network parameters to increase capacity and this seems to have been demonstrated," continued Alan Stewart-Brown.
But he added that although the networks are holding up well for now, should people spend "a lot of time streaming Netflix, BBC iPlayer, online Gaming or other types of streaming media then this is likely to cause a problem and may force the network operators to ‘limit’ some of these streaming services to ensure airtime fairness to all users".
Looking ahead, he says that technologies like 5G will hold the answer, as it deliver "greater than 100X boost to capacity both in terms of data speeds and the number of simultaneous or concurrent connections that can connect to any one cell.”
