Text messaging has a tendency to fail at places where you need it most. In high-concentration areas, such as music festivals and stadiums, networks can get overloaded by all the traffic.

Cellular coverage is often nonexistent when hiking, or on airplanes and cruise ships. There are very good technical and economic reasons why connectivity fails in these situations, which is why the solution may be something completely different. One application that geeks have been paying particularly close attention to is FireChat. The app uses a relatively new technology called mesh networking to allow users to communicate wirelessly on their smartphones without being connected to the internet.

FireChat, created by a startup called Open Garden, previously offered only a group chatroom of people around you or those interested in discussing a specific subject. On July 29th, the app got an update that adds off-the-grid private messaging for the first time. This works as a relay: Your phone’s wi-fi or Bluetooth antennas can pass a message to another phone running FireChat, located up to 200 feet away. That phone relays the encrypted message on, until it’s delivered. That process can take 10 to 20 minutes to travel across a dense metro area, assuming about 5 per cent of the city’s population has downloaded the FireChat app big assumption.

But the promise of such a feature is inspiring. It could help international travelers avoid pricey roaming fees when they're only looking for a way to locate family. On a plane ride, two friends stuck in seats on opposite ends of the aircraft could pass the time sending messages without paying for a Gogo Internet plan. "We end up having a network that's comparable to any mobile carrier's," says Micha Benoliel, chief executive officer at Open Garden. "It's a completely new form of routing. We see the beginning of this new mobile Internet that's enabled by people. People have the capacity to build these completely dynamic networks that don't require infrastructure."

The feature could also prove popular in developing countries, where access to traditional mobile networks can be too expensive for many locals, and it could help in places where freedom of speech is curtailed and internet traffic censored or monitored.

Some 5 million people have downloaded the FireChat app worldwide so far, with many of them in the US, Iran, and Hong Kong, where it was used during the recent student uprising. Users can create chatrooms, which work online and offline, and gather more than 10,000 people to discuss everything from football games to politics to Italian food.

”We are going after the fraction of the market where the other messengers don’t work,” Benoliel says. Many other companies are trying to make access to mobile messaging cheaper and easier, though they’re relying on the traditional mobile network to do so. Facebook already offers free access to its social network in 45 countries. Bharti Airtel has experimented with giving mobile subscribers in Kenya free access to Twitter, which has its own private messaging feature. And, of course, Facebook-owned WhatsApp lets smartphone users exchange messages without having to pay texting fees to their carriers.

FireChat can forgo carriers entirely, which makes it very different from these other projects and fairly complementary. If you’re in a city with reliable internet, you probably won’t want to wait 20 minutes for your text to reach its recipient.

Bloomberg