Demand for data centres has exploded over the past five years due to increased adoption of AI and cloud computing, both of which require massive amounts of computing power.
But what is a data centre, and how does it work?
City AM was invited inside one of Virgin Media 02 (VM02)’s largest data centres in the UK, located in Slough, to find out.
As Thomas Finch, VM02’s technical site operations manager, explained, the facility is the operator’s largest mobile data centre in the UK.
“Everything you do on your mobile phone – voice calls, texts, whatsapp, social media – passes through this data centre”, he said.
Increased demand
With millions of people relying on their mobile and broadband services daily, data storage and processing demand has skyrocketed.
A recent report by TechUK estimated that the UK data centre sector could grow tenfold by 2035, boosting the economy by £44bn, creating 40,000 jobs in the process.
Currently, UK data centres contribute £4.7bn in gross value added (GVA) and generate £540m in tax revenue.
The UK government recently classified data centres as critical national infrastructure in response to this boom.
Network testing
The infrastructure supporting this data hub is vast, including a network of fibre-optic cables connecting users nationwide.
VM02’s site houses several ‘faraday cages’, which are shielded enclosures designed used for network testing.
These allow engineers to conduct controlled 3G, 4G and 5G tests without interference.
Due to their controlled environment, no cellular signals penetrate these spaces.
They, therefore, require landlines for communication inside.
Apple also operates its own Faraday cage within this VM02 centre to test its services securely.
Powering a city’s worth of data
A critical element of these data centres is resilience, which is built into the infrastructure from the beginning.
The site operates with multiple layers of redundancy to ensure its continuous service and reduce failures.
In the event of an external power failure, the site’s UPS (uninterruptible power supply) kicks in, supplying direct current power until generators take over.
Its generators are capable of powering two of three residential streets, with 2,000 litres of diesel on-site to sustain operations during an outage.
To put it into perspective, while a typical home uses 300KW of energy a year, VM02’s consumes the same amount in just an hour.
Regular maintenance is also essential.
Every quarter, engineers simulate a power failure to test the resilience of its backup systems.
A nerve centre for the UK’s digital economy
Beyond mobile, VM02 plays a key role in broadband across businesses and homes in the UK.
Finch described the data centre as the “heartbeat” of Virgin Media 02.
It supports 45.1m users, including customers of Tesco mobile and other mobile virtual network operators.
The centre also provides connectivity in popular public spaces like McDonald’s and Sainsbury’s wifi hotspots.
It supports stadium networks like Twickenham, where coverage is optimised exclusively for those inside.
VM02 invests £10bn into its network, spending £2m daily on mobile infrastructure alone.
It recently launched its 5G standalone service, dropping its reliance on older mobile generations.
Why Slough?
Slough’s strategic location has made it one of Europe’s largest data centre hubs.
Situated just outside the M25 and less than 10 miles from Heathrow, its first data centre opened in 2005.
Today, the area is a key hub for digital connectivity for banks, emergency services and major corporations.
This centre sits on the UK’s “data centre highway”, explained Finch. “It’s close enough to London but far enough to ensure reliability and rapid access for engineers”.
The area is also home to major hyperscale data centres operated by tech titans like Google and Netflix.
Network monitoring
VM02’s data centre also plays a key role in tracking network performance and addressing customer reported issues.
A user-driven app, My Network, allows customers to manually report faults, while data is also crowd-sourced to monitor network performance.
AI-driven automation helps to detect and resolve coverage gaps for their users.
The network also supports blue light emergency services, providing infrastructure for businesses and customers alike.