How Glastonbury Festival builds a city-sized phone network for just one weekend

In 2010, data usage at Glastonbury reached 0.11 terabytes; this year it's expected to pass 60 terabytes. Here's how Worthy Farm copes with the increasing demand
WIRED

When Glastonbury Festival comes to Worthy Farm, it turns the normally-sleepy patch of Somerset countryside into a temporary city, population circa 200,000. “You’re looking at a city the size of York that all needs to be set up in the space of two or three weeks,” says Tom Bennett, EE’s mobile innovation director.

EE has provided mobile network coverage to Glastonbury for 19 years, which means building the on-site infrastructure each year from scratch to support festival-goers and their growing data demands. No longer are people content to bring along a dumbphone for the week; now they expect full connectivity, not just to make calls and send messages but increasingly to upload images and stream video to social media too.

In 2010, data usage over the Glastonbury network reached 0.11 terabytes. In 2013, the first year of 4G at the festival, it jumped to 12.3, and at the last event in 2017 (2018 was a fallow year) it rose to 54.2 terabytes. The busiest time for data uploads was during the “legends” slot on Sunday afternoon, when Bee Gee Barry Gibb took to the Pyramid Stage. This year, EE predicts that data usage will pass 60 terabytes – with 5G being brought to the festival for the first time to take on some of the load.

The main challenge is not coverage but capacity, given the tight geographic space people are packed into. “We’re looking at Glastonbury being the size of York, but the capacity required is more like central London,” says Bennett. The engineering team sets up six temporary mast sites for the festival, supplemented by one permanent site erected in 2017 (which, Bennett jokes, probably makes the local village one of the best-connected in the country for the other 51 weeks in the year). This year, EE aims to support 5G at three of the sites.

The key part of each site is the antenna. In most built environments, antennae are installed on rooftops, but this isn’t possible in a field. Instead, they are raised five to ten metres high on lattice towers. This year, EE is trialling a pneumatic system that uses air pressure to push the antenna up on a telescopic pole, reducing the risks incurred by engineers climbing and rigging the towers. The sites are delivered on trailers two weeks before the festival and each has its own power generator. The network is monitored at all hours by an operation centre based in Bristol, and an engineer stays on-site with a set of spare parts.

Demand on the network moves and fluctuates over the course of the festival. It is densest in front of the main stages, around campsite accommodation and near food stalls, with some less predictable peaks. In 2016, an unusual spike was seen on the Friday morning, before any acts had started playing. This was caused by news of the EU Referendum result, as attendees went online to read the latest and share their reactions on social media. In 2017, there was a spike in downloads on Saturday morning, thanks to rugby fans streaming the first Test between the Lions and All Blacks (video is a particularly large traffic driver).

As well as presenting a unique challenge, Bennett says that Glastonbury also makes a good testbed for new technologies such as 5G, which EE is rolling out more broadly in the UK this summer. While the engineers start designing the next festival’s setup almost as soon as the previous one has finished, they can never truly put it to the test until the big weekend arrives. As Bennett puts it: “You can’t easily mimic 200,000 people in a field without putting 200,000 people in a field.”

This article was originally published by WIRED UK