Google’s Spectacular Skydive

Posted by Sam Churchill on

Google’s spectacular skydiving stunt at Google I/O last week, appears to have used Ubiquiti Rocket Dishes and Rocket M radios on a variety of frequencies to provide Wi-Fi to the skydivers wearing The Google Glass Project, according to the Ubiquiti forum.

The Google Glass team thinks ‘Wearable Computing Will Be the Norm’, reports Steve Levy in Wired. On Google+, Sergey Brin posted the following:

We had an amazing time putting together the demo that we did for Glass today at Google I/O. The video below from some of our testing really captures the feeling of freedom that our project aspires to.

The aerial footage was captured on Glass. The higher fidelity footage was recorded locally on the device whereas the hangouts were live streamed at a much lower resolution because of the challenges of networking a skydiver inflight.

Because we were unable to get regular wifi (which is built into Glass) to work under those conditions, we had to use extra networking gear which was tethered via usb to the device (and also provided extra battery for long days of testing).

Google had to establish a reliable link to the airship, more than a mile away, and additional links to each jumper via WiFi. The jumpers descended about one mile to the roof of the Moscone Convention Center in San Francisco.

Ubiquiti’s 5 GHz Rocket M radio linked to AirMax sectors MAY have been used to deliver PtP bridging for the airship. That product is said to have up to a 50 km (30 mile) range (depending on antenna). A Ubiquity Power Bridge (data sheet) might also be used for point to point links. It has a 25db gain and a 6 degree beamwidth.

AirMAX is Ubiquiti’s proprietary TDMA protocol. It allows each client to send and receive data using pre-designated time slots. AirVision (data sheet) is Ubiquiti’s turnkey video solution. It provide remote recording and analytics using Ubiquiti’s line of H.264 megapixel IP cameras. Google, of course, was using their Glass device.

The blimp had broadcast cameras on board. It was also being shadowed by a helicopter. Those cameras and uplinks probably didn’t utilize WiFi. They probably used standard broadcast television solutions.

Troll Systems makes a tracking system commonly used by television stations for live helicopter shots. Their SkyLink Mini controls the onboard antenna and ENG transmitter, keeping the HD signal locked on the receiver.

Typically a NSI Superquad receive antenna is mounted halfway up a tv station’s mast for helicopter shots. Most likely, the broadcast cameras on the helicopter and the airship used broadcast solutions.

According to Sergey Brin, connecting the skydivers required each diver to use a different RF technology. They appear to have been linked both inside the cabin, then while jumping one mile down. But Google’s Glasses used their USB connection on the down-link, not their embedded WiFi, which was too weak to go the distance.

An ArsTechnica board says:

My friend at Google informs me the glasses were plugged in via USB to Macbooks strapped to the skydivers’ backs, which were then relaying the video feed via 5GHz 802.11n down to the dishes on the ground.

That sounds right. A tiny 5GHz Bullet M (pdf) could provide a signal boost for the down link.

The Ethernet from the Macbook may have run through a Ubiquiti 5GHz Bullet M, which outputs 600mW. With a short omni antenna, it could fit under the arm of the jumper. That would form a bridge to the rooftop antenna.

On the ground, a compatible Rocket M Titanium radio (pdf) on Moscone fitted with a Rocket Dish provide plenty of gain.

Repelling down the side of Moscone and the bike relay through the corridors must also have been tricky.

But forget the technology. Elinor Mills at C/Net has the inside story on how Google got permission to carry out such a potentially dangerous and unprecedented stunt in downtown San Francisco.

Somehow it all worked. Amazing!

Posted by Sam Churchill on Sunday, July 1st, 2012 at 11:51 am .

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