GoTenna Gives Work-Around for Smartphone Dead Zones With goTennas, a text message travels from smartphone A to goTenna A to goTenna B, then to smartphone B -- all in milliseconds. A goTenna uses Bluetooth LE to pair with a smartphone, then low-frequency radio spectrum to communicate directly with another goTenna. An app provided with goTennas is used to send messages or share a location.

Smartphone users often become used to the frustration of sitting in a dead zone with no Wi-Fi or data service. But if a New York City start-up has its way, those times will be a thing of the past. GoTenna is taking pre-orders for its flagshiphardware product, which it says will let smartphone users communicate via their own closed network much like a high-tech pair of walkie-talkies.GoTennas are sold in pairs. One user keeps an antenna nearby (in a pocket or backpack -- something within 20 feet of a phone) and it connects to his or her iOS or Android phone via Bluetooth low energy, or Bluetooth LE. A second user does likewise. If the two antenna holders are separated, the goTennas create a closed network using low-frequency radio waves, and users can send messages to one or more goTenna users without connecting to a telephony network or Wi-Fi. The company says no messages are stored on a server, guaranteeing user privacy. A free app provided with the antennas is used to type a text message or share a location. That message travels from smartphone A to goTenna A to goTenna B, then to smartphone B -- all in milliseconds. The provided app also offers offline maps and full messaging capabilities. Range Varies The range offered by goTenna depends on the user’s location and nearby topography or environment. The company offers an interactive module on its Web site that simulates what to expect in various environments and elevations. GoTenna says the antennas can reach 50 miles in range if they’re in the right location. That range narrows down to a few miles in congested urban environments. The goTenna battery will last around 72 hours with intermittent use and around 30 hours if it’s on constantly, according to the company. When turned off, it can hold a charge for more than a year. The developers say the product was borne of frustration reaching friends and family via smartphone even when they were in areas that presumably should have solid reception. They say one application for goTenna is in emergency situations -- company co-founders Daniela and Jorge Perdomo came up with the idea during Superstorm Sandy in 2012. We asked CEO Daniela Perdomo why nobody else has thought of this idea before. "There is something of an innovation paradox when it comes to goTenna's technology," she said. "We're marrying old, not-very-sexy RF engineering with the modern smartphone, and making them both better in the process." Daniela serves as the company CEO while her brother works as CTO. Units Selling Fast The Perdomos developed goTenna using their own money, then raised $1.8 million in seed funding last year. Among their backers were Bloomberg Beta, Andreessen Horowitz and MentorTech Ventures. A crowdfunding pre-sale aimed to earn $50,000 with goTenna. While the company wouldn’t disclose how many units it had sold in the pre-sale, "we can tell you that we reached our $50,000 campaign goal in 2-1/2 hours," said Daniela Perdomo. The antennas sell for $150 per pair during the pre-order period, but the price will double once the discounted units are sold out. The units will ship in the fall.