UmTRX is an open source hardware transceiver and a partner project of Myriad-RF, and  the company who developed it, Fairwaves, have been deploying it to to create rural mobile telecoms networks at a fraction of the cost of traditional solutions.

About the project

The problems of rural telecoms are well known; mobile comms are essential to rural communities in developing nations, but how does a telecom operator roll out a network costing more than a small community could ever repay through subscriptions.

Furthermore, if a community wanted to do it themselves, how would they pay for it if they don’t benefit from the economies of scale that the operators enjoy.

A small village in Mexico has found a way, and last month saw the culmination of two years of work as the Rhizomatica project started to install GSM mobile networks in remote Mexican communities, with Santa Maria Yaviche becoming the first village to benefit from the new system.

Idyllic or isolated? Image credit
Remote: Yaviche is 5 hours drive from the nearest city


A small community of around 700 inhabitants, Yaviche is located deep in the northern Oaxaca mountains – about 5 hours drive from Oaxaca City.

On September 27th, 2013, villagers made their first local calls using Fairwaves UmDESK equipment, which has a built-in PBX and doesn’t need any external infrastructure to connect calls.

This means that villagers can make calls to one another via the open source base station even if the unstable satellite Internet connection goes down. And, because they’re being routed locally, calls between villagers are free.

This means, for example, that villagers can call one another for help if they get bitten by a snake, or that the doctor can make phone calls rather than rounds to check in on patients.

First calls in Yaviche – image credit

Getting phones

Surprisingly, in a village of just 700 people with no mobile coverage, the network immediately detected more than 100 active phones – the phones have been bought as inexpensive calculators, alarm clocks, games machines etc.

Two weeks after installation, the Yaviche mobile network had more than 400 phones registered. In a typical day the Yaviche mobile network connects 500-1000 local calls and delivers 3000-4000 SMS messages. Users find it a very useful tool, for example the village doctor now calls all his patients to check on them without having to walk around the whole day. People working in the fields can call home to let them know of their whereabouts and if there are any problems.

The next step for the village is to get a stable internet connection to be able to connect to other surrounding villages. The doctor in Yaviche mentioned that it would be handy to connect Yaviche to a nearby community, Talea de Castro, because they have a clinic and a lab and he could diagnose people faster if he could call those. Luckily, Talea is a part of Rhizomatica and runs its own GSM network as well.

The technology used

UmDESK and two 2W boosters
Yaviche antenna mast – made of bamboo

The network in Yaviche runs with a UmDESK, powered by Fairwaves UmTRX. It allows up to 14 concurrent voice connections. When this capacity is exhausted the system switches settings to nearly double its capacity, making a trade off in voice quality.

The base station is located in a corner of the village and thus two patch antennas are used to direct radio transmission to the village’s centre. Antennas are hooked to a 6m bamboo pole, placed atop a two-story building. This setup covers the whole village, providing coverage even inside the thick-walled buildings found in the region.

And it’s not only the hardware that’s open source; this project runs the of OsmoBTS  open source software, (an alternative to OpenBTS, that gives better scalability).



Coverage map of the installation (online map)

The effect on the status quo

This concession is a result of 2 years of working with these communities and the government, and could herald tectonic shifts in mobile industry regulation.

Now Mexican communities can join Rhizomatica and build their own small mobile networks, without having to go to the incumbent mobile operators and their suppliers. As mentioned, traditionally, a mobile operator concession in a country of Mexico size costs 100’s of millions of dollars, meaning only large corporations can enter the market. Who always have their priorities elsewhere, but to serve rural communities. Mexican mobile operators refuse to install their equipment in villages with less than 5,000 inhabitants. This leaves out almost all villages in rural Oaxaca! The effect on coverage and access is strong with around 50,000 rural localities in the whole Mexico without cellular service.

Using open source technology brings communication networks to rural communities that would ordinarily be deemed unprofitable. Will the operators adopt this model? Probably not. But the potential is clear and it highlights the need for much more progressive approaches to spectrum management.