Cellular network operator O2 on Friday said its data networks had been restored after millions of smartphones across the UK and Japan were taken offline yesterday (via BBC).

A statement on its website said the 4G network was finally working again, after having been affected from about 05:30 GMT on Thursday.

o2 ericsson
Earlier, mobile network equipment supplier Ericsson said that an expired certificate was the reason behind the outage, which also created problems in several other countries. Ericsson UK boss Marielle Lindgren said the "faulty software" that had caused the issues was being decommissioned.

Both O2 and Ericsson issued a joint apology to millions of customers hit by the disruption. "I want to let our customers know how sorry I am for the impact our network data issue has had on them, and reassure them that our teams, together with Ericsson, are doing everything we can," said O2 boss Mark Evans. "We fully appreciate it's been a poor experience and we are really sorry."

O2 is owned by Spain's Telefonica and has the UK's second-largest mobile network after British Telecom subsidiary EE.

The company said voice calls were not affected by the problem, but some O2 customers said they could not make calls or send texts, despite having cellular reception.

The outage also had knock-on effects for other services that use the O2 network, such as Transport for London's electronic timetable service at bus stops, which stopped working for most of Thursday.

Top Rated Comments

fullfast Avatar
70 months ago
Vodafone is the Verizon of the UK. I’ve tested all the networks and for me it was the best by far. Glad O2 is good for you
30 million total impacted by it and all because some dope forgot to renew a certificate so it expired.....that is just pi$$ poor management

Luckily for me I am on both Vodafone and o2 so minimal impact but it does just show how reliant we are now on being able to access internet services.......rewind 15 years....you were lucky if you could receive texts let alone look at what some dog or cat is doing on insta :)
Score: 4 Votes (Like | Disagree)
BMcCoy Avatar
70 months ago
As frustrating as yesterday’s outage was, I still think we do quite well in the U.K. for our cellular deals, whether calls or data. We pay about a quarter of what it costs in the US.
Score: 4 Votes (Like | Disagree)
jimthing Avatar
70 months ago
I moved from O2 to EE when I got a Series 4 on launch. Very happy. My wife and kids are on O2 still, and I didn't hear from them all day yesterday. Who do I send the thank you letter to?
Here's the address:

(FAO) 'Men escaping constant annoying trivial family calls' dept
Santa Claus
iCloud
Earth
Space
Universe
Score: 3 Votes (Like | Disagree)
NoFace1006 Avatar
70 months ago
Vodafone is much better.
You're joking aren't you?! Although I should say that everyone has different experiences and it depends where you live, etc. Had several family members on Vodafone over the years and it's always been terrible for data, particularly data reception more so than the speed. In the end everyone has moved over to other networks, I've been with 3 for 18 months after switching from O2's network, couldn't be happier. Went to the top of Scotland to visit family, a no reception area for most networks in places, I was the only family member with signal and data access.
Score: 3 Votes (Like | Disagree)
coumerelli Avatar
70 months ago
They apologize by you still get billed for the time it was out I bet...
Yeah. All 0.17£/€/¥. lol
Score: 2 Votes (Like | Disagree)
roar08 Avatar
70 months ago
It'll be interesting to find out of this tantalizing Mac rumor turns out to be true.
Score: 2 Votes (Like | Disagree)

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