From 16 – 24 September 2007 the Noborders network set up a camp as a base from which to demonstrate against immigration detention centers in Sussex, England. Throughout the camp, Indymedia UK ran a media centre including a dispatch system for news reporting and a public access point in the middle of a farmer’s field. In case it’s useful to anybody doing something similar, here’s how we set it up.
Connectivity
The biggest technical worry was the question of internet connectivity. In previous camps in the UK, we’ve arranged to get the Psand bunch to help us out with their satellite gear and solar-powered laptop setup, but for this one they weren’t available.
Our only realistic option was to use 3G mobile connectivity. We had a T-Mobile web’n’walk card kicking around, and access to an account with a transfer limit of 10GB/month. We were quite worried about 3G network coverage prior to the event, especially as the location wasn’t known until the last minute (police harassment meant that the location changed two days before the camp was due to start).
Initial tests at the site revealed that although GPRS connectivity was great, the much faster UMTS network signal was unstable when using the card with its internal antenna. GPRS is the normal mobile data network, and it’s quite slow, weighing in with about twice the speed of a 56K modem on average. This wasn’t going to be particularly useful for the full-service media centre we envisioned, although we did do some experiments with Squid caching and probably could have made it work OK if we had to do so. As a backup plan, we thought about coding up a website that would work on the local area network. The idea was that people could use this local site to submit content, with submitted content being queued and uploaded to the Indymedia UK site as bandwidth became available. This turned out to be not necessary as the UMTS network worked extremely well once we picked up a UMTS antenna from Panorama antennas.
The antenna plugged into a port on the side of a Novatel Merlin XU870 3G mobile data card. It was necessary to buy an adapter wire to make the Merlin connect to the 3m antenna cable, which then connected to a Client Patch antenna. Signal was still extremely weak and unstable, but by rotating the antenna slowly through 360 degrees and doing a big download, we could watch the transfer speed and figure out which way to point it. We then duct-taped the antenna to a pole outside the media tent. Once this was done, the signal was extremely stable and quite fast. Average download speeds ranged from 50-100 KB / second, with bursts up to 130 KB / second.
We ran the uplink on a Windows XP laptop, using T-Mobile software that came with the data card to do the dial in (basically it’s just a really fancy PPP modem setup). A Linux project called umtsmon provides the same functionality in Linux but we couldn’t figure out how to connect to UMTS rather than GPRS, and didn’t have time to fuck around forever. In theory the Merlin will run perfectly under Linux, but the setup instructions for it aren’t particularly fantastic and we weren’t sure what parameters we needed to enter in order to get the card working with the T-Mobile account.
Bandwidth considerations
The account in question had a download cap of 10 GB, and we weren’t sure now much bandwidth a media center in full operation actually used. As it turned out, the first day’s data transfer total, which was the result of people doing editorial work on the imc-uk site, was only about 45 MB. This made us much more confident that we weren’t going to run the account out of its bandwidth allocation, and over the next few days it was pretty much open season on tcp/ip packets, with people downloading software, uploading video, doing system updates, etc.
Eight computers in heavy use, without any caching system at all, resulted in an average of 500MB / day. This could have been massively reduced if necessary through the use of squid caches, a full set of software installation CDs, apt-caches for software packages that weren’t available locally, etc. However, it was interesting to see what the maximum transfer was, prior to worrying about all the rest of it. Upload speeds were in the 50 KB / second range, which was perfectly acceptable for doing large video uploads.
The network
We had a total of 8 computers available, mostly laptops running Ubuntu 7.04 with a Mac G4 for video editing. Also some nice Dutch people gave us an old laptop running Debian which came in handy. There was nothing too special about most of the network setup, which included a 16-port hub and a 5-port hub as well as two wireless stations (one for each of our media centre tents). The only major trouble came when trying to do the initial network setup. Windows networking setup, with its endless dialog boxes, opaque instructions based on outdated screenshots, and almost total lack of native networking applications in XP Pro, was a nightmare. Hours of screwing around with the Internet Connection Sharing shit in XP resulted in the realization that this great OS doesn’t actually give out IP addresses in any comprehensible way. We finally got pissed off and downloaded a copy of Tftpd, a simple GPL dhcp server for Windows, and set up the network as follows:
a) we disabled the FTP and SNMP servers that run by default.
b) we set up a subnet on the 192.168.0.x IP range, and configured DHCP to start giving out addresses on 192.168.0.2, with 100 addresses in the pool (maybe a bit optimistic considering there were only ever about 500 people on the camp at the most). The router address was 192.168.0.1, and after initially having some problems we smoothed things out by also setting the gateway address and DNS address to 192.168.0.1
c) once the PPP tunnel to T-Mobile was running we had to right-click on the Merlin’s connection in the Network control panel, go to the “advanced” tab, and tick the “share this computer’s internet connection” box. This gets unticked every time the Merlin connects, but luckily the signal was really stable and this didn’t turn into a major hassle.
Closing thoughts
Things worked out incredibly well, and given an appropriate power source (in this case, a 5000w generator) we should be able to use a similar setup to run mobile public access points at any time or place of our choosing as long as a 3G network account is available. The antenna setup cost 60 quid and should work with pretty much any data card as long as the appropriate card adapter lead is available. The opportunities for mobile video and audio streaming are also quite interesting.
T-Mobile accounts come in two packages, either a 3 GB/month account with the stipulation that users don’t stream stuff (29 quid per month) or a 10 GB/month account allowing streaming (44 quid per month). There is also the option of buying pay as you go cards with a transfer limit of 45 MB within a 24-hour time period. This would be enough to run a really lean media centre with text reports, and it might be possible to do video stuff by burning through a bunch of SIMs, changing each one when it hits its 45 MB limit.
