Wi-Fi pirate radio
Publication date: 27 April 2008Originally published 2007 in Atomic: Maximum Power Computing
Last modified 03-Dec-2011.
When technology becomes cheap enough to be effectively disposable, interesting things happen.
Lithium batteries, rare earth magnets and high-intensity LEDs are all pretty young technologies. But all of them are also now cheap enough that people with a few spare bucks can combine all three into cheerful little rainbow-coloured magnetic fireflies - "LED throwies".
Throwies still cost around 50 cents each, even when you buy your batteries, LEDs and magnets in bulk. But a couple of hundred of 'em can go a long way.
The other day, I was considering what it'd take to make a solar-powered LED throwie. The price could be only a couple of bucks if you've got a source of broken solar cells - you can attach leads to quite small cell fragments, and a small piece of cell per throwie would be enough, especially if you included a flasher circuit to keep the draw down.
But then it occurred to me that autonomous, solar-powered, close-to-free Wi-Fi repeaters would be a much cooler idea. You could throw 'em around at random, onto people's roofs, up into trees (well, into trees that don't have too many Wi-Fi-eating leaves, anyway), anywhere you liked. It'd be pirate-radio wide-area networking!
At the moment, no such thing exists. About the closest you can get are mesh networking gadgets, like the ones sold by Meraki. The Meraki boxes are too expensive to just toss around the place - and Meraki have only been making them more expensive, with some highly questionable changes to the firmware and licensing. And the Meraki boxes, like every other network appliance in the world today, also use too much power for guerrilla solar applications. But they illustrate the principle well enough.
Each Meraki box has an antenna, a DC input jack, and an Ethernet port. Basically, if the box can see the Internet through its Ethernet port, then it works as a wireless access point. If there's nothing connected to the Ethernet port, it works as a mesh-network relay. If there's something on the Ethernet port but no Internet access, the box relays and provides Internet access, from any other Meraki boxes on the network that can see the Net.
Meraki have even announced a solar-power kit for their waterproof "Outdoor" model. Unfortunately, the Outdoor costs $US99 by itself (the non-waterproof "Mini" is $US49), and it's been months since the solar kit announcement now and they still haven't announced a price for it. Given the other restrictions Meraki gear has sprouted, in arrant contradiction of their original "hackers welcome" policy, it looks like a much better idea to build your mesh from consumer access points running the free OpenWrt firmware. You can buy those off the shelf now from Open-Mesh, a company which appears to actually be doing what Meraki originally promised to do. Open-Mesh is selling ready-to-go boxes for fifty bucks a pop, or only forty, if you buy at least 20 units.
But no matter which way you go, there's no really cheap option for mesh networking yet.
If you've got a lot of spare money, a ladder and no respect for private property, though, you could already be stealthily deploying Open-Mesh or other such gadgets all over your neighbourhood.
I think trees and roofs would be favourite. Tempting though it is, mesh network relays strapped to telegraph poles probably wouldn't last very long.
These sorts of graffiti-artist escapades are not, of course, very attractive to anybody who can actually afford to buy dozens of solar-powered relay boxes, even if they're now less bulky than they used to be. But once the hardware's own price falls to a few dollars per unit, and the power needed for a mesh relay drops to well under a watt, we'll be in business.
That little power would only require about a $5 battery-charging solar panel, if the new wave of half-price solar cells hit the market as promised. And it won't, of course, be the end of the world if the panel's a bit undersized, so during winter the batteries conk out a couple of hours before dawn. That's just the world telling you to stop playing Team Fortress 2 with other slackers on the neighbourhood net, and go to bed.
A one-watt mesh node may sound like a bit of a tall order, but remember that the OLPC XO-1 laptop-for-kids (which I wrote about a while ago here) has mesh-networking hardware built in. And the whole XO-1 laptop has a power budget of about two watts.
The XO-1's wireless networking is based on a couple of Marvell Libertas chips that have full TCP/IP networking functions built in. This means that the network chips can work as a super-lightweight mesh relay all by themselves, with the rest of the laptop powered down.
The XO-1 maximises battery life by restricting its network speed to a maximum of two megabits per second, but that's A-OK for ordinary Web browsing. And I wouldn't be surprised if the network hardware by itself could be kept working 24/7 by a few solar cells - and maybe even batteries - harvested from old LED garden lights.
Sneaking around in the middle of the night picking garden lights like flowers is another activity I do not recommend. You could actually get this whole deal rolling without breaking any laws at all.
There's nothing at all illegal, here in Australia at least, about Wi-Fi-ifying your whole suburb, as long as you get permission from all of the people on whose property you want to deploy your hardware.
That probably won't be too difficult, if you explain to them that they'll be getting a free (if slow and unsecured) Internet connection out of the deal. That's pretty much how wireless community networks, including more than a few Australian ones, are spreading at the moment.
If you want to sell Internet access in Australia, then you'll need to shell out big bucks for a carrier license. But if you give it away for free, and don't exceed the quite lenient output power restrictions, you'll be golden.
Most ISPs have anti-sharing requirements in their license agreement, but as long as mesh users don't in the aggregate do anything more obnoxious than a typical user would do (and mesh hardware can be set to throttle the bandwidth available to each individual node, preventing one porn fiend from absorbing 99% of the bandwidth 100% of the time), the ISPs a mesh connects to are unlikely to care, or even notice.
I look forward to buying a Dick Smith kit containing those two Marvell chips, an antenna and a battery.
And, perhaps, a magnet.
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