07.30.02
Billing World and OSS Magazine
by John L. Guerra
Appearing in Billing World and OSS Magazine in April 2002
Cell Towers in the Sky
Try this on for size: A company known as Space Data wants to launch narrowband repeaters attached to balloons to provide signal in remote areas of the United States.
The repeaters, which will transmit two-way paging signals, will hang from the balloons on the ceiling of the world, far above weather and air traffic. Think of it as a network that’s higher than cell towers and lower than satellites — a place that so far no one has tapped.
“They’re 25 times closer than a satellite — they’re in a sweet spot there,” says Tim Ayers, a spokesperson with Space Data. “We’ve had excellent signal strength.”
Space Data’s business plan, of course, raises a lot of questions. How, for instance, does the balloon stay where it’s supposed to stay? What about air traffic, weather and other vagaries of mid-air technology? In other words, how do they plan to make it work?
Weather Service a Telecom Partner?
It all starts with the
balloons, which are modeled after the National Weather Service’s (NWS) weather balloons.
The repeater and balloon combination costs about $300. The
repeater, little more than a circuit board, will be attached
to balloons and launched every 12 hours. Space Data is negotiating
with the NWS to obtain “colocation” agreements.
The company hopes the NWS will let it use its launch sites
around the nation. In return, Ayers says, Space Data will
agree to provide the NWS with GPS-enabled balloons, something
the agency doesn’t have.
“The weather service is still using a prior generation of location technology,” he says. “They want to move to GPS, but that would triple their costs. We build a better balloon, so we can help their forecasting ability. If they agree, we’ll suddenly have 70 launch stations around the country.”
Space Data, headquartered in Phoenix, has run trials in the Southwest. The helium-filled devices climb at a respectable thousand feet per minute, shooting upward through air routes to their position in about 100 minutes. The balloons are about 6 feet across on the ground but expand to about 26 feet once they hit the high altitude. Personnel on the ground track the balloon using 900 MHz radio transmitters and relay commands to manipulate ballast that slows or lowers the balloon.
Can You Repeat That?
The wireless phone user sends a message,
and the nearest repeater in the sky grabs the signal and
sends it along to the next balloon. “As a call goes through our system,
we can identify the phones in range and then send the signal
to those phones,” Ayers says.
Space Data hopes to have a constellation of balloons to push the signal along until it hits the receiving phone or picks up a ground cell tower. The 50,000 launches a year will cost the company $15 million. Some wireless carriers pay $60 million a year on tower leases, not including maintenance or construction, Ayers says.
Balloons last about 48 hours, Ayers says. They automatically deflate and degrade at their working altitude. Once that happens, the repeater — enclosed in a lunchbox-sized plastic foam container — is released and goes into free-fall. A parachute deploys at a designated altitude, and the device floats to the ground. The repeater contains instructions — including a reward notice — for returning it to Space Data, in case someone comes across it in a field or backyard.
The company can be profitable even if none of the repeaters is ever found, Ayers says. “Our business plan is based on getting none of them back.”
More Balloons, Better Coverage?
The company plans to launch
backup balloons to ensure that signal is never lost.
“System A goes up at midnight, and system B goes up 12 hours later,” Ayers says. “System A then goes into sleep mode. If system B goes down, we can go to the other balloon. This creates redundancy in the system.”
Personnel on the ground can monitor the network’s performance by grabbing data from the airborne repeaters using the 900-MHz transmitter. “We identify sky sites that are having any problems,” Ayers says. “Adjustments are made on the ground up; with GPS we know where every balloon is. We can [launch] replacement sites.”
Monitoring a Network in the Sky
The radio device, as well
as ground stations — which
are about the size of a VCR — keep the ground personnel
in touch with how well the network is performing.
“We can determine which balloon is dropping the packets by contacting it. If it doesn’t respond to our query, we know it isn’t working,” he says. “Quality of service metrics are obtained from the ground using the radio, which then sends the data to the ground station device, that will communicate with our national operations center in the Phoenix area and record it there.” From there, the data is available in reports, either printed, on CD-ROM or through real-time transfer over data lines.
“We can measure network flow, megabits per second, and other parameters,” Ayers says. “It’s very important for us — and carriers — to know the system’s performance and capabilities.”
Because the repeaters weigh less than 4 pounds, they are free from Federal Aviation Administration restrictions regarding payload. (Aircraft must be designed to withstand an impact from an object that weighs 6 pounds or less.)
The company hopes to begin offering the service in February 2003. It is still conducting talks with paging and other wireless providers. “We’ll be offering voice in about two years,” Ayers says.