Ever been in a crowded place and you can’t get service on your phone to make a call? AT&T Verizon & T-Mobile care… kind of.

Sometimes there are too many phones on your service provider’s network. Smartphones have made the situation worse, because watching videos and chatting on FaceTime hogs the network.

Three carriers just signed an unprecedented deal to try and solve that problem. For the first time AT&T Verizon and T-Mobile have agreed to experiment with sharing network space with each other and the federal government.

In the past, the government has auctioned off network space, known in geek speak as wireless spectrum. Each carrier got its own spectrum. But they desperately need more. The Feds have it and its sitting mostly unused, reserved for the military.

Carriers have been after Washington for eons to auction it off. But there are reasons not to like what if, heaven forbid, there’s a war and the military needs it?

Sharing it between all the carriers and the feds seems a natural solution, but it’s not something that the carriers ever wanted to try. They’d rather let their competitors run out of room.

But this chunk of spectrum is so big and juicy the three have agreed to experiment with sharing it. (More geek speak: 95 MHz of spectrum in the 1755 – 1850 MHz band.)

The biggest selling point: this spectrum is already being used by carriers in Europe, “so there are plenty of smartphones available without having to manufacture products with new frequencies,” wireless industry pioneer George Schmitt told Business Insider. Schmitt is CEO of MB Technology Holdings, a company that makes the tech that lets carriers share spectrum and one of the guys that invented the wireless industry. As former CEO for one of the first mobile phone carriers, PCS PrimeCo (now Verizon Wireless), he bought $2.5 billion worth of spectrum from the feds 16 years ago.

Schmitt says this deal would let carriers handle double to quadruple the number of phone calls and video downloads they could handle now.

“Demand could go up a couple 100 percent and there will still be plenty of capacity,” he says.

Better still, if carriers could figure out how to share, this could lead to better coverage in rural areas and faster adoption of a new wireless technologies, like something called White Spaces Super Wi-Fi.

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