C&B Notes

A Cutting Edge 2G Network

It is well documented that network-connected cell phones are fundamentally changing daily life, but this is particularly true in third-world environments where legacy communications infrastructure is lacking and/or poor.  Many of these places still do not have access to commercial cell networks, and an organization named Rhizomatica is working to address these gaps with old, now open source cell phone technology.  Necessity is truly the mother of invention (or at least innovation).

The tower — which Hernández, Yaee’s blacksmith, welded together out of scrap metal just a few hours earlier — is the backbone of Yaee’s first cellular network. The 90,000 pesos come in the form of two antennas and an open-source base station from a Canadian company called NuRAN.  Once Hernández and company get the tower installed and the network online, Yaee’s 500 citizens will, for the first time, be able to make cell phone calls from home, and for cheaper rates than almost anywhere else in Mexico.

Strategically ignored by Mexico’s major telecoms, Yaee is putting itself on the mobile communications grid with the help of a Oaxaca-based telecommunications non-profit called Rhizomatica.  Its founder, Peter Bloom, is among the men currently getting soaked on the roof of town hall.  It’s May of 2014, and this is the third of what he jokingly calls “artisanal cell phone installations” that he’s led in the Sierra Juárez in the past year and a half — the first of their kind in the world.  By the end of the year, he will have installed six more networks all over the state of Oaxaca, bringing the total to nine.  Armed with an experimental concession from the Mexican government that grants Rhizomatica access to coveted cellular spectrum all over the country, Bloom is slowly but surely bringing coverage to towns that have been left out of the 21st century’s most important technological revolution.

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We’ve all heard plenty of uplifting stories of the democratizing potential of cell phones, how they’ve brought everything from voice calls to mobile banking to people who have never had access to landlines and laptops. Cell phones “have definitely proven the most ubiquitous piece of communication and digital hardware that people own on earth,” says Bloom.  But on its own, “your cell phone doesn’t really know how to do anything,” he explains.  All of the utility is in the network.  And by and large, that network is provided — and, therefore, controlled — by a company that wants to make a profit.

That profit comes from subscribers, and if there aren’t enough of them in a particular region, cellular providers simply refuse to install their infrastructure there.  Some countries get around that economic reality by legally requiring telecom companies to build networks in rural areas, no matter how many people end up paying for a contract.  Mexico doesn’t have any such laws, meaning that Yaee, with its 500 residents, doesn’t stand a chance of attracting a commercial provider.

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From a hacker’s point of view, mobile communications came along at just the wrong time.  The first commercial systems were deployed in 1991, right before the internet emerged from the academy and started making its way into people’s homes.  By the time a strong open source community came into being, cellular networks were locked up behind walls upon walls of patents and proprietary equipment.  Even today, “it’s very difficult to get your hands on the technology,” says Harald Welte, an open and free source software developer in Germany who works on mobile communications.  It wasn’t until around 2006 that old base stations started showing up on eBay, giving interested hackers like Welte a firsthand look inside the (albeit already outdated) technology that made 2G mobile networks possible.  Out of straightforward intellectual curiosity, Welte snapped up a few and, four years later, he was able to make the first call on his reverse-engineered, open source network, dubbed Open BSC, referring to the base station controllers that coordinate traffic on a cell network.  Now, Rhizomatica is pushing Open BSC to its limits out in the real world.

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The communities pay 120,000 pesos ($8,000 dollars) upfront for the equipment and installation, about one-sixth of what the commercial provider Movistar charges for a similar rural installation. Ninety thousand of the pesos go to buy the hardware, and the rest covers Rhizomatica’s time and expenses. Subscribers to the community network pay 30 pesos (about $2) per month for all local calls and texts, and the town keeps any profit left over after paying for electricity and maintenance. Thanks to a Mexican company called Protokol, which provides internet access all over rural Oaxaca, Rhizomatica can also hook up the town’s network to a voice-over-IP connection, which allows users to make very cheap long-distance calls to Mexico City and even the U.S., where many people have relatives.  Once the network is installed, Yaee’s residents will be able to call the U.S. for 20 centavos (less than 2 pennies) per minute.  A similar call from one of the town’s public landlines runs 15 pesos (about $1) per minute, a prohibitive cost for many residents.

Still, commercial networks have “20 years of headway” over the open source approach, Welte says, and Rhizomatica’s community networks can suffer from their distinct DIY feel. Bloom, Hernández, and the rest of the team must make sure to install Yaee’s tower above one of the town hall’s windows, so they can run an extension cord through it and plug the base station into a wall socket. That means whenever the power goes out in Yaee — which happens frequently, especially during the May-to-September rainy season — they lose the cell network, too.  And until the town could raise enough money to move the entire installation to higher ground than the town hall’s roof (which happened in August 2014, three months later), there was no guarantee that Rhizomatica’s signal would be able to reach up the hillside to where Hernández and a good portion of Yaee’s residents live.