Network transparency: How future mobile networks could be built in glass windows

Ericsson(s eric) engineers have begun experimenting with a new type of cell site – one embedded inside a window. As demand for mobile data grows, networks must get denser. That means building increasingly smaller cells and putting them much closer to mobile users. So why not take advantage of the glass surfaces that cover our homes, businesses and vehicles?

At CTIA Wireless this week, Ericsson Networked Society Evangelist Mats Guldbrand gave me a demo of the technology at the equipment maker’s booth. Basically, a small antenna element is embedded into a pane of shielded glass. That antenna can pick up Wi-Fi or cellular signals from nearby phones, tablets and laptops and then aggregate those connections, sending them as a combined transmission to the nearest LTE cell tower.

Ericsson Antenna GlassGuldbrand gave an example of a bus containing 50 people all surfing the internet on their smartphones. Each device is trying to connect separately to the same tower, and you wind up with a big mess. Not only are all of those signals interfering with one another, the network is trying to manage 50 simultaneous hand-overs between cell towers. The network might be able to pull it off, but everyone’s experience suffers, Guldbrand said.

If those 50 devices, however, were all connecting to localized antennas embedded in the vehicle’s windows, the bus could then link to the cellular network through a single transmitter mounted on the roof. It’s much easier for the cellular base station to handle a single high-capacity connection than a bunch of smaller connections. Everyone in the bus experiences greater speeds and more resilient links, and since each device isn’t reaching out to a distant tower, their device battery life is spared.

This might sound a bit like the repeater or range-booster kits you can buy to enhance your cellphone’s signal at home, but this technology is designed to integrate closely with the network. Normally a repeater would create all kinds of interference in a crowded network, but by using shielded glass Ericsson can limit the number of competing transmissions bouncing around the cell. The treated windows (and the steel frame) block signals trying to escape the bus, turning it into a kind of Faraday Cage on wheels.

Forthcoming LTE-Advanced technologies will introduce network relay points mounted on bus rooftops and utility poles, which would route signals within the cell. The principle is simple: if you can narrow the distance between network hops you get more resilient and higher-capacity connections.

Ericsson has other plans for connected glass. Guldbrand said that as long as the windows are networked, you could embed all kinds of technology into their surfaces. As part of the demo, Guldbrand showed me a pane of plain glass with an infrared field on its surface. When you interrupted the field with your hand at specific points, you triggered actions like turning on and off the lights or skipping between songs on the stereo. So not only the windows in your future home access the internet, they could replace your light switches and remote controls.

Feature photo courtesy of Shutterstock user irabel8