Megabits to a farm: Getting Internet to a hacker camp

In our last post, we discussed how the network is distributed both wirelessly and wired around the site. Here we’ll look at the other side of the equation: how the network is brought to the field in the first place.

It’s a tall order

In an ideal world, these events would take place in fields next to large data centres. But as parking lots aren’t usually great for camping, there’s always the challenge of getting Internet access to the site in the first place.

Last year our peak usage was about 140Mbps 5-minute average, and roughly symmetric usage. This time we’re expecting three times as many attendees, so at least 420Mbps. Actually, now that the word is out about EMF, we are expecting a higher proportion of campers who are used to the European hackercamps where bandwidth is plentiful, so the bandwidth required is likely to be even greater.

Of all the available access technologies, we could immediately discard most due to being unable to provide enough throughput (ADSL, FTTC, EFM, and so forth), which left us with just two: radio and fibre.

imageFibre circuits have a minimum term of at least 12 months, and high excess construction charges if fibre doesn’t already exist (such as at a remote farm). And, unless the site is on-net with a carrier’s existing network, it’s always going to rely on Openreach products for the last mile.

EMF is in an awkward position where it has enough attendees that it has high bandwidth requirements, but not enough that the budget can stretch to a 12 month fibre contract without major sponsorship, which wasn’t forthcoming this time around (if any carriers who read this would like to help out in 2016, do get in touch!).

This left us with radio.

Telehandler Operator Will Hargrave was quoted after EMF 2012 as saying “I’m never doing microwave again”. But as this was the only remaining option, and he had plenty of hair left to pull out, we had to try.

Big masts

imageWe’re putting a 30m mast up a hill on the site and cabling this back to the on-site NOC data centre, housed in a 20ft refrigerated container. However, this year we’re the opposite side of Milton Keynes from before, so we needed a new location to run the radio link to.

Colocker is a new data centre in Milton Keynes that provides lockers for colocating servers. They’re letting us put the other mast up in their parking lot and are generously providing a pseudowire back to Docklands.

So from the NOC-DC, we run fibre up the hill to a mast, radio over to Colocker, copper into their data centre, and then a 1Gbps pseudowire down to Telehouse.

Big radios

imageWe’ll be using DragonWave radios again in Ofcom-licensed frequencies. Initial results from the survey last week indicate that we should be able to get around 436Mbps from each radio each direction to/from site, however there are line-of-sight issues that we hope to solve with a taller mast.

Bitlair are also bringing a pair of Ubiquity AirFiber units running at 24GHz that we’ll have available as a secondary/backup link.


As is now common with these events, we are running a multi-homed default-free BGP network under our shiny new AS60079. We’ll be taking transit from AS42579 Sargasso Networks as well as peering with other ISPs at LONAP.

It’s also traditional to run a publically-addressed network with no NAT and no network-level interference in the end-to-end data path. This means that each and every device for each and every attendee gets a public IP address. It also means we don’t run any kind of firewall or interfere with or inspect your packets in any way - those of you used to having a NAT “firewall” protect you from attack had better be prepared.

Naturally, IPv6 is enabled throughout the network and should “just work” for everyone. If you encounter any problems, we do recommend that you don’t disable IPv6, but instead try to understand what has gone wrong and fix it - the InfoDesk can help here. The 21st century is when everything changes, and you’ve gotta be ready.

More information

There’s more information on how to use the network, including a few “do”s and “don’t”s, on our wiki page.

Have a question? Drop us a line at or follow us on Twitter.


imageWe’re especially grateful to Colocker for arranging the transport down to London. If you’re looking to host servers on the Internet, check out their new concept in colocation.


Retro Gaming!

EMF 2014 sees Awesome Retro returning, this year joined by Retro Games Party!

Awesome Retro are a non-profit organisation based in the Netherlands dedicated to bringing the joy of gaming to events around Europe. They’re bringing their fantastic selection of consoles, along with some fabulous decorations (if you’ve seen any photos of last year, you can’t help but notice the giant pacman).

Retro Games Party is the conglomeration of two classic arcade collectors into one unbelievable arcade based in Bolton. They’re actually having their grand opening the same weekend as EMF so can’t represent in person, however they are lending us as many arcade machines as we can fit into the back of a van.

Have a look at both Awesome and Retro’s collections and let us know on twitter if there’s anything specific you’d like to see!

How to network a field: Internet-to-the-tent at EMF 2014

Delivering a reliable high-speed wired and wireless network to a campsite in just over two days is something of a challenge. Fortunately, the NOC team is filled with people who have done just that year after year at events across Europe and the world. The network this year is based on those experiences and on our work at EMF 2012.

This is the first of two blog posts we’ll be releasing about the network setup. Here, we’ll talk about the on-site network. Next time we’ll talk about our uplink and connections to the Internet. 

Let’s start with where the network connects to you, the camper.

Wired Network

imageDespite all available evidence, this is not a public toilet. This is a Datenklo (German: “data toilet”), or DK for short. We use them as distribution points for network and power across the field, because they are conveniently-sized lockable containers, provide protection against the weather, and are relatively cheap to hire.

imageInside each DK is a power distribution box with circuit breakers, one or two network switches, and a wireless access point. Often they come with a free roll of toilet paper.

We expect all camping areas to be within 50m of a Datenklo. Most are closer, but we recommend you bring up to 50m of Cat5 cable if you want to connect to your tent. Likewise, if you want power, it is best to bring a long cable (although it is likely that there will be closer distribution points around the field if you instead bring a 16A commando connector).

Just leave your cables in an obvious position outside the door so we can see them, and someone will be around to connect them up regularly. If this doesn’t happen quickly enough, you can follow the instructions on the DK to tweet or SMS us.

Note that, to prevent inadvertent network loops, port-security is enabled on all edge ports. So you won’t be able to connect more than one device to a port. If you want to connect a switch, come and talk to us on-site in the NOC and, as long as you sound like you know what you’re doing, we’ll raise the restriction on your port.

Distribution and Core

imageThis year we’re anticipating much higher bandwidth usage, so our network architecture has grown to suit. DKs will be cabled back, using fibre or Cat5e, to one of three distribution switches acting as aggregation points, located around the field in DKs. Each will take the Gigabit Ethernet port-channels from 8-12 DKs each and aggregate them into 10-Gigabit Ethernet uplinks into the core.

The CCC have lent us their reels of outdoor fibre, which are allowing us a much more scalable network design over a larger area. FlexOptix are kindly loaning us all the optics to plug into the switches. The fibre SFPs are something akin to magic: they use different frequencies in each direction to allow bidirectional communication down a single core of fibre.


The other thing inside (or possibly on top of) a DK is the wireless access point. We aim to provide seamless wireless coverage and roaming across the entire field including all the camping areas. Thanks to the sponsorship of Aruba Networks, we’ll be deploying their access points across the field, all tunnelled back over the wired network to a centralised 7210 controller in the NOC that will handle authentication and roaming. So even if you walk from one end of the field to the other, your IP address will not change and your connection should be seamless. In some places you’ll even be able to get a 802.11ac gigabit-speed wireless connection.

In a departure from the norm, this year the main wireless network will be using WPA2-Enterprise. This ensures that everyone gets their own key and are safer from snooping. We still recommend using end-to-end encryption, but this will help protect you. To connect to the network, join the “emfcamp” network and use the username “emf” with password “emf”.

If your device doesn’t support 5GHz, you can join the legacy network “emfcamp-legacy”, but be aware that this is less resistant to interference and will be less reliable. Use the other one if possible.

For those really old devices that don’t even support WPA2-Enterprise, there’s a network called “emfcamp-insecure”. Please don’t use this unless you really have to.

How can you help?

imageThe NOC team is always a popular one, but we don’t really need any help during the event. By Friday morning, the network should be up and running perfectly and we’ll be putting our feet up! What we do need help with is setup and teardown. During setup, there are a LOT of cables to run (at least 5km worth), RJ45 plugs to crimp, and switches to deploy, and then the whole lot needs to be collected up at the end. At the moment, we’re looking fairly good for setup, but we need more help for teardown.

If you’re interested, please drop a line to letting us know when you can arrive and when you have to leave. You’ll even get fed!

More information

There’s more information on how to use the network, including a few “do”s and “don’t”s, on our wiki page.

Have a question? Drop us a line at or follow us on twitter.


We are grateful to our sponsors Comtec who are providing the access and core switches and routers, LONAP who are providing the Summit x650 distribution switches, Aruba Networks who are providing the access points and wireless LAN controller, and FlexOptix who are providing the necessary optics to link it all together.


Announcing the shiny things!

Every year people build amazing things and install them all over the site. Here’s a rundown of some of the projects coming to EMF this year.

Bar Arm

Behind the bar you’ll find a robotic barman in the form of an ex-laboratory robot arm mounted on a mobility scooter. It’ll try and serve you drinks, but we can’t promise it won’t throw them at you instead.

A Tune On A Stick

Somewhere on-site you’ll find a lighthouse-like structure making strange noises. It plays a tune while spinning around - what it plays depends on who is nearby. Find some friends and try standing around it in a circle.

Giant Pixel Sign

A giant interactive sign made up of 900 RGB LEDS controllable from your web browser, lurking somewhere in the dark. Upload your own artwork, or your favourite gif!


Desperate for some Club Mate but don’t want to move? Call the Robobutler! He’ll trundle across the site and deliver you a tasty beverage, hopefully without destroying tents in his rush to do your bidding.


A large forest of radiant “trees”. As you move through the·grid it senses your presence and initiates a ripple of light & clicks, however it will be used in several ways - expect a multiplayer maze amongst other things!

Giant Ride-on Duck

The folks from Tog in Dublin have built a giant duck you can drive around. We don’t know why, but we want a go anyway.

ISS Tracker

This giant arrow will spend all weekend tirelessly pointing at the current location of the International Space Station. Unfortunately there will be no visible ISS passes during EMF, so (time permitting) an interface is planned to allow pointing at other astronomical points of interest.


The buggy that almost self-destructed hauling things around EMF in 2012 has been repaired and is better than ever, with a new trailer for hauling your equipment around and a smattering of ridiculous addons. Internet-connected golf cart anyone?

Retro Gaming

Back by popular demand the retro gaming tent has ballooned in size! Expect to find full-size arcade cabinets, pinball, and every retro console you can think of.


Adding to our list of autonomous vehicles is BigHak, a giant ridable version of the Big Trak toy you may have had as a child. Either drive it manually, or program it Big Trak-style with the accompanying phone app - we have a prize for the first person to successfully program it to navigate to the bar from their tent!

Cocktail Barbot

Somewhere in the Nottinghack village you’ll find a two meter long automatic bar. Choose a drink from the menu, insert a glass at one end and get a cocktail down the other - even down to the tiny umbrella and slice of lemon.


Balloons floating high above the site listen for noise and tell one another how loud it is. As the pings move between them they pulse with colour, lighting up colourfully in waves across the site.

Giant Hammock

In 2012 we had a giant hammock made from fishing nets - in 2014 we’ll have an even bigger one!

Kite Arch

24 kites mounted on a long cable - once the wind gets up the arch takes off! As the weekend progresses they’ll be being decorated as an ongoing workshop.

The LHS Bikeshed

The LHS Bikeshed is a 3 player starship disaster simulator in a caravan. Players are trained to fly the ship and then given a short scenario that inevitably ends up with them being exploded, burned, suffocated or smeared across the surface of a planet. Find three friends and set off into the galaxy!


An amazing sea of fish that respond to touch. Individual fish light up and move, before spreading colour, light and motion through the entire SHOAL. The fish tell their friends what’s happening and a motor means all the fish can swim in the same direction, or turn to face someone who has come to play!

Pacman! On a Sphere!

A version of Pacman that is played on an actual real-world sphere. The pac-man player must run around the projected sphere trying to find all the pills, whilst up to another four players play the ghosts trying to hunt him down!

The Nuclear Poker Bunker

A half-size Hexayurt Quad Dome, within which people play Nuclear Poker, a card game designed to teach Generals too young to remember the Cold War about Mutually Assured Destruction.

The Kinematocinegraph

A chance to sit out in the night air and quietly enjoy flickering images from the past. A small antique box contains a projector filled with silent films from - sit, be calm, and watch films for as long as you like.

Pedal Power

Two pedal power generators powering a small sound system, a bubble machine and LED lights in the evening. Get some exercise!


Hidden in the villages is a large umbrella adorned with meteorological equipment, generating a weather-related soundscape and light show for those standing underneath.

The Marvellous Booze Fogger

A device for the turning of alcoholic spirits into the most inhalable of mists, pleasing to the tongue and satisfying to the mind. A very certain panacea for the ills of the soul and a solution for those tired of the sorrows and trials of day to day living. It is most shiny:

Are you bringing an amazing project to EMF this year? Let us know!

EMF 2014 Childcare: Welcoming the Nanotechs

The EMF team strives to make every event better than the last; more accessible, more fun, and easier to attend for a broad range of people. We’ve always wanted to provide childcare for those with young children but the costs were prohibitive, and until recently we thought it would be impossible.

This year UCL have stepped in to make it a reality and we’re pleased to announce that EMF 2014 will have a full programme of children’s activities, and free childcare available for tiny engineers. We dubbed them the Nanotechs.

From 10am to 8pm up to forty children between the ages of 0-12 can be left under the supervision of professionals from Nipperbout, an Ofsted registered childcare provider.

Nipperbout will be keeping them entertained with all kinds of activities, and everyone comes away with a Nanotech certification. A limited number of very little ones (0-2) can be accommodated - they’ll be looked after separately in the Startup Incubator.

You don’t have to leave your children there all day - simply check them in and out whenever needed as long as there’s space available.

We’ll also be running activities and classes for all young people throughout the event in the Nanotech Lab next door - everything from soldering lessons, to kite mapping, to making your own robot! If you’d like to run something for our young attendees, get in touch.

At lunchtime on Saturday UCL will also be hosting a family-friendly Geek Showoff on one of the main stages. Expect to see UCL researchers and festival participants sharing funny tales of mistakes, science, and engineering suitable for all ages.

Tickets for EMF 2014 are on sale right now - under 5s get in free, and tickets are just £40 for under 16s!

All this would be impossible without the support of UCL Engineering, and we can’t thank them enough. We hope that this makes the festival more accessible and enjoyable for families.


Announcing TiLDA MKe, the incredible EMF 2014 camp badge

Electromagnetic Field is an event that celebrates technology, science, engineering, and weird inventions. For every event we design a badge, but our badges aren’t made of cardboard or plastic. Our badges take batteries.

For EMF 2014 we’re proud to announce TiLDA MKe, probably the most advanced conference badge you’ve ever seen.


What it does

TiLDA MKe is all about the talk and workshop schedule. If everything goes to plan you’ll be able to browse the latest schedule on the badge, automatically updated by a network of radio base stations across the site. Paper schedules ain’t got nothing on us.

Every badge can be registered online so it will automatically alert you about upcoming talks, events or workshops you’re interested in. This time you won’t miss that session on miniature submarines piloted by trained bees. We promise.

The badge will also have a few other practical applications, like a handy torch-mode (with dedicated button) for locating your tent in the dark, a rain alarm, and as many fun applications as we can write in the remaining weeks. We might even port some classic games for you to play on your way home.

Every attendee will receive a TiLDA upon arrival. You can take it home afterwards and use it to experiment with programming. Or build a 3D printer. Or a spaceship.

What it is

At its heart the badge is an Arduino Due compatible 32bit ARM Cortex M3. A rechargeable battery will keep it running for days, and you can charge it over USB when the juice runs out. We added a 128x64 pixel LCD screen, two RGB LEDs, a radio transceiver, joystick, accelerometer, gyroscope, speaker, infrared, and all sorts of other fun parts. It’s compatible with Arduino shields and has dedicated connectors for electronic textiles.

Like every great IT project, this one is running fashionably late, so keep an eye on the website to see what we manage to get done! If you’d like to help out, get in touch.

How we made it

Hardware like this doesn’t come for free, but it also doesn’t come out of your ticket price. We want EMF to be as affordable as possible, so TiLDA is completely provided for you by a number of incredible sponsors: Ragworm have spent the last six months dealing with our unreasonable requests while they fabricate and assemble the boards. Element 14Paypal, and Mathworks jumped in at the last minute to save the project from near certain failure, along with Ciseco, Twilio, Imagination Technologies, Shadowcat Systems, ComtecCodethink, Pimoroni, and LPRS.

If you see someone representing them around the site, thank them. They’ve been amazing, and we couldn’t have done it without their help.

The badge has gone through numerous revisions. Work on it started over a year ago, and for the last six months a dedicated team has been frantically working to make it a reality. The final design (in lovely Ragworm orange) is a thing of beauty.


What can I do with it?

The main goal of TiLDA is to give people something that allows them to explore and play with technology they may be unfamiliar with, while allowing advanced users to push the boundaries of its capabilities. We don’t want your TiLDA it to sit in a drawer after EMF is over - we want you to use it again and again.

We want to you experiment, so during the event we’ll be running workshops to teach you what you can do with your badge: everything from basic electronics to programming it in MatLab. Someone might even help you turn it into a tiny robot.

The badge is based on an Arduino as they are the most widespread hobbyist electronics development board. But this time we made sure to give you an ARM processor so more advanced users can play with all the fun bits we tucked into the design. You simply need to download the Arduino software and try out the examples.

What are you still doing with it?

We’re in the final stretch, finishing the firmware and preparing the radio network. We’ll be documenting everything completely, but you’ll soon be able to find more information at

In the meantime, all our code and the badge design itself are available on github.

We’re tremendously excited to see what you do with the badge at EMF this year. Just in case you’ve not bought a ticket yet, they’re on sale right now.

Again, thank you to all of our incredible sponsors that have made this happen, and to the team that has worked on this for a solid year.












EMF 2014: Speakers

With a month to go until Electromagnetic Field 2014 opens, it’s time to announce some speakers! This year we’ll have over 90 speakers across three stages, with workshops happening in parallel all over the site.

Our Call for Participation is still open so if you’d like to get involved with EMF go and submit a talk or workshop. Don’t worry if you’ve not heard back yet - our selection process is ongoing.

We’re pleased to announce six amazing speakers today, with many more to come in the following weeks:

An Operator’s Guide to the Enigma Machine

Simon Singh, bestselling author of Fermat’s Last Theorem & The Code Book, will be demonstrating his German Enigma machine and discussing how it was cracked during the Second World War. He’ll also be covering the history of encryption from Ancient Greece through to the Information Age.

How to be an Effective Terrorist: Fear and Loathing in Cyber Security

Dr Jessica Barker is a security consultant often present in the media helping people to understand the threats they are exposed to. She’ll be talking about how we should be explaining risks rather than hiding them from users, allowing people to effectively manage their online activity and protect themselves.

The three main parties railroaded the Data Retention Act through in a week. Where does the fightback begin?

In 2010, Tom Watson MP was one of the few members of Parliament fighting the Digital Economy Act. Since then he’s published a book on corruption at News International, and in July 2014 he sued the UK government over the recently passed DRIP act. He’ll be talking about how citizens can fight back and protect themselves against ubiquitous surveillance.

Why Fantasy is the Key to Motivation and Creativity

Leila Johnston is a writer, journalist, podcaster, and speaker who also organises events on weird technology and art alongside a companion quarterly magazine. With the aid of unique hand-made 8-bit console slides she’ll be discussing her relationship with technology, motivation, and creativity, and explaining what possessed her to write a branching narrative novel.

Hacking the ZX Spectrum

Ben Heck, famed retro console modder and youtube star, will be talking about how he recently miniaturised a ZX Spectrum to make it portable and playable on-the-go. He’ll also be talking about some of his other mods that have been widely publicised over the years.

Zoë Star: Neurotic IoT Machines from an Alternate Reality

Rachel Rayns is Raspberry Pi’s creative producer. She’ll be introducting her Zoë Star machines - satirical art works poking fun at the Internet of Things, Quantified Self and Digital Natives whilst (hopefully!) creating some charming and inspiring interactive experiences.

If these talks sound good, tickets to EMF are on sale for £105.

2014 Starts here!

All previous blog posts are from 2012, so they’re only relevant if you’re interested in EMF history.

Revealing TiLDA, our camp badge!

Its been a long-standing tradition at US and EU hacker camps to give people a badge that does more than hang around your neck, and we really wanted to have something similar for Electromagnetic Field. Thanks to sponsorship from the UCL Institute of Making, we’ve developed one specially for this camp.

We call our badge TiLDA, and every attendee will receive one when they arrive at the camp!

TiLDATiLDA is a completely reprogrammable battery-powered development board that hangs on a lanyard around your neck.

By default it communicates with all the other badges on site, playing a networked game that encourages you to meet other people with differing interests. They also communicate with things on site, but more about that soon.

The design is fully open-source and based on the Arduino compatible Vinciduino, as we wanted to give people a device that they could actually use for something useful after the camp has ended, rather than sitting in a drawer.

TiLDA is powered by an ATMega 32U4 and comes equipped with 2.4 ghz wireless communications, infrared communications, two RGB LED’s, and a powerful lithium polymer battery that is rechargeable via microUSB. It also has a button, just in case. There are plenty of free I/O pins for you to augment your TiLDA, and it can be programmed using the standard Arduino software. We can’t wait to see what you do with it at EMF.

The badges are sponsored by the Institute of Making at UCL, home to a new hackerspace for university students. Without their assistance TiLDA could never have got off the ground! We also need to thank the amazing Charles Yarnold, who spent many sleepless nights working on the badge.

Right now the badges are being manufactured at a fabrication house in Scotland, and as soon as they reach us we’ll be posting photos for you all to see!

EMF Camp, the site and Networking

Provisioning high bandwidth connections is always fun, especially those that are only required for a very short period of time, and most notably, out in the middle of a field.

We’ve been very lucky to have Pulsant sponsor us. They’re providing us with rackspace in both their Milton Keynes datacentre and in Telehouse East in London Docklands, giving us our own 1Gbps circuit between the two. Using this we’re constructing our own multihomed network, with multiple transit and peering connections, ensuring speedy Internet access for the entire camp.

Due to the 2.8km distance between the Pulsant data centre and Pineham Park, we’ll be erecting temporary 30 metre tall masts and creating a point-to-point microwave link to connect the camp. As you can see the masts are pretty impressive!

radio mast at emf camp

Here is a brief overview of what our core network will look like:

EMF Camp network diagram

(bigger version)

Like all large hacking events in Europe (HAR2009/CCC) we’ll be using portaloos, or datenklos, to house network switches and power distribution around the site. If you want super-fast wired access please make sure you bring a 40 to 50m Cat5 cable with you to connect your tent! (we are still finalising power plans and will post about these shortly).

toilet network hubs

(credit binarycoco)

Chaos Computer Club in Germany are lending us their event IP address space, so everyone at the camp will get a real public IP. At the moment we’re working on configuring the core network, wireless controllers and various services (DNS, DHCP, monitoring etc).

EMF Camp network kit

flexOptix have sent us the first shipment of loan optics, we’ll be using these to building multiple rings around the site, linking venues and dateklos.

networking optics

At the site we will have blanket wireless coverage on 2.4GHz (b/g/n) and 5GHz (a). If you have any particular network requirements, or if you plan to use any non-Wifi devices in these frequency bands, please let us know in advance at

Finally, a big thanks to Nick Ryce and Matt Lovell at Pulsant for providing the rackspace and circuit between London and MK, CCC for use of their address space, and flexOptix for loan of their SFP optics.