VILLA TALEA DE CASTRO — Left out by telecom firms like the one owned by billionaire Carlos Slim, a remote Mexican mountain village now runs its own cellphone network to communicate with the outside world.

Tucked away in a lush forest in the southern state of Oaxaca, the indigenous village of Villa Talea de Castro, population 2,500, was not seen as a profitable market for companies such as Mr Slim’s América Móvil.

So the village, under an initiative launched by indigenous groups, civil organisations and universities, put up a perch-like antenna on a rooftop, installed radio and computer equipment, and created its own micro provider called Red Celular de Talea (RCT).

Now, restaurant manager Ramiro Perez can call his children and receive food orders on his cellphone at a cheap price in this village dotted by small homes painted in pink and yellow.

The local service, started in 2013, costs 15 pesos ($1.20) a month — 13 times cheaper than a big company’s basic plan in Mexico City — while calls to the US, where many of the indigenous Zapoteco resident have migrated, cost a few pennies per minute.

"I have two children who live outside the village and I communicate with them at least two or three times a week," says Mr Perez.

Before, he had to use telephone booths where he paid up to 10 pesos a minute.

The coffee-producing village installed the network with the help of Rhizomatica, a nonprofit organisation with US, European and Mexican experts that aims to increase access to mobile telecommunications in communities that lack affordable service.

Rhizomatica, a civil group named Redes and a town official say they hope a telecoms reform, pushed through Congress by President Enrique Peña Nieto to open the market, will "break the obstacles" that prevent the development of such community-based projects.

"Many indigenous communities have shown interest in participating in this project and we hope that many more can join this scheme," the groups say.

The equipment used in Talea, which was provided by California-based Range Networks, includes a 900MHz radio network and computer software that routes calls, registers numbers and handles billing. Calls to the US are channelled via a voice over internet protocol (VoIP) provider.

The village received a two-year permit from the Federal Communications Commission to have the right to test the equipment.

When a cellphone user arrives in the village, an SMS automatically appears saying: "Welcome to the Talea Cellular Network (RTC) — to register, go to the radio with this message."

There is one catch: phone calls must be limited to a maximum of five minutes to avoid a saturation of lines.

Israel Hernandez, a village resident and one of the volunteers who helped set up the system, says the network uses the radio-electric spectrum that "telephone (service) providers refuse to use because it is financially unviable".

Mr Slim’s Telcel is part of his América Móvil empire, which controls 70% of Mexico’s mobile phone market and has 262-million subscribers across Latin America but never made it to Talea.

Alejandro Lopez, a senior town-hall official, says the village has approached big telecoms firms but they required 10,000 potential users as well as the construction of a path where an antenna would be erected and a lengthy power line.

"Despite some technical problems, because we are in a test period, the project has been a success", Mr Lopez says, with 600 villagers signing up in the first three months.

Buoyed by the system’s success, the village has decided to buy its own equipment that will allow RCT to run 35 lines simultaneously and plans to install it in the coming weeks.

The next step, RCT volunteer Mr Hernandez says, is to form co-operatives with other villages to request concessions from the Mexican government in order to resolve "this lack of free frequencies for cellphone communications in the country’s rural communities".