James Watt knows the secrets of hidden London better than anyone. He's one of Vodafone’s pedestrian testers.

One man and his backpack, helping to improve our network

James Watt knows the secrets of hidden London better than anyone. He’s an unassuming 30yr old with sandy hair and shorts who can tell you where to get the best view of the 10 Downing Street garden, the stories of the city’s homeless, and what Mayor Boris Johnson gets up to in his office.

James walks up to eight miles across London in a day as one of Vodafone’s pedestrian testers – and he’s wearing surprisingly ordinary shoes.

“Yeah, they’re getting a bit worn down now,” James says, tugging at where the sole is coming away, “but I do have proper boots for days I know I’m really going the distance.”

Although his checked shirt and headphones plugged into Snow Patrol make him look like a tourist, James’ backpack has five identical, specially modified, smartphones loaded up with testing software. The handsets test signal strength, quality for voice calls – and send and receive mobile data.

Inside James Watt's bag, a selection of smartphones constantly tests the network

The results are automatically fed back to our servers, but as a back-up James stops to log the time he spends at each location in a notebook. He’s also got a plastic folder full of detailed maps numbering the set places he has to monitor en-route.

At the moment James is based in London, but six teams of pedestrian testers are out walking the streets of 24 other towns and cities every day, covering as many as 115 locations a month and getting in to hard-to-reach urban areas where network testing vehicles can’t drive, like shopping malls, sports stadiums, airports, offices and railway stations.

Detailed maps tell James where to wander next, and how long to stay there

Network Quality Manager, Andy Cooke, explains, “We’re continually monitoring our urban networks from the ground up. We try to reflect the customer experience”, says Andy, “so the phones automatically make and receive phone calls, download web pages, upload files and simulate people sending emails, for an up-to-the-minute picture of our overall network performance.”

Pedestrian testers cover as many as 115 locations a month

Part of that means that James has to replicate what a normal Vodafone customer would do – which usually entails walking quite slowly:

“I have to match how an ordinary person would walk, although sometimes I have to slow down to a crawl, or even stop, if more detailed measurements are needed,” James says.

Indoor maps help James pinpoint potential trouble spots inside buildings

“I get approached by a lot of charity collectors, and homeless people, and we sometimes end up chatting about how they ended up on the streets.”

In six months on the job James has lost more than a stone in weight, and is glad to see the back of dark winter mornings and driving rain. “This job has shown me what a vibrant, varied, city London is – and it definitely looks better on days when you can walk through St James’s Park in the sunshine.”

James has tested every floor in London’s City Hall, and peered into the Downing Street Garden from the Horse Guards building on Whitehall, which he says “looks like it hasn’t changed since the Second World War.”

He’s ridden the London Eye in the name of signal testing, been deafened by the chimes of Big Ben, and has been doing some rigorous extra planning and checking for some of the big events coming up this summer.

Wherever he goes, James is armed with a selection of smartphones

In fact, there’s barely a nook and cranny from Stanmore to Surbiton that he hasn’t explored, so if you need to know the best place to nab one of London’s free newspapers, change Tube lines, or pick up a latte – he’s your man.

Urban areas may not be remote locations, but tall, densely packed buildings, and the sheer number of people, can put a high demand on the network. Pedestrian testers play one part in a much larger process of making sure that you get the best quality the first time, and every time, you make a call. Other parts of that process are carried out by road and train, but testers like James – quite literally – put in the legwork.

“London rushes by while I’m testing,” he shrugs and puts his earphones back in – looking anonymous again as he disappears out into the new concourse at King’s Cross station with his backpack full of phones.

Can you spot our pedestrian tester?