3G Cellular Service Tested at 65,000 feet in the stratosphere

[Paul L Rinaldo]

Gang,
FYI
Paul

>23rd July 2002

>
>  <http://www.3g.co.uk/PR/July2002/SkyTower.jpg> SkyTower, Inc., in
collaboration with the Japan Ministry of Telecommunications and NASA,
successfully completed a series of commercial telecommunications tests -
the world's first from more than 65,000 feet in the stratosphere. 
>
>The tests, which began three weeks ago, were conducted from
Pathfinder-Plus, an unmanned solar-electric aircraft developed by
AeroVironment, Inc., the parent company of SkyTower. Both companies are
based in Monrovia, Calif. 
>
>The solar-electric powered Pathfinder-Plus took off from the U.S. PMRF
Naval Base in the morning, climbed to more than 65,000 feet in the
stratosphere, and reached its operating station in the early afternoon.
>From this position over the scenic island of Kauai, Pathfinder-Plus
transmitted several hours of next-generation mobile voice, data, and video
services to multiple handheld user devices on the ground. 
>
>"These tests demonstrate the viability of the SkyTower stratospheric
telecommunications platform as an excellent complement, and in some cases
alternative, to satellite and terrestrial systems for a broad range of
applications," said Stuart Hindle, vice president of strategy and business
development, SkyTower. "The airborne platform, operating above the weather
and commercial air traffic, is equivalent to a 12-mile-tall tower, which
means significant advantages to telecom service providers and broadcasters." 
>
>Picture-Perfect Video Broadcast Signal 
>
>The first flight successfully tested the world's first digital high
definition television (HDTV) broadcast transmission from the stratosphere,
providing a picture-perfect video broadcast signal to a fixed receiver on
the ground, at twice the resolution of conventional broadcast transmissions. 
>
>Because of its much higher look angle, SkyTower platforms can fill in
"urban canyons"-coverage areas missed by terrestrial and satellite
broadcast transmissions due to tall buildings, terrain, and the like-and
can do so using a fraction of the power. During the tests, a 24 Mbps data
rate was achieved using only 1 watt of power - less than 1/10,000 the power
used by a typical terrestrial broadcast transmitter that has to overcome
buildings, trees and other obstructions to cover the same area. SkyTower's
local footprint can also help satellite broadcasters overcome capacity
challenges that limit their ability to provide local channels within each
market.
>
>Low-Cost Wireless Communications Infrastructure 
>
>The HDTV broadcast was later followed by an IMT-2000 (third-generation or
"3G") mobile test that demonstrated video telephony using an off-the-shelf
NTT DoCoMo handset sold in Japan, and Internet surfing from a wireless
modem-equipped laptop at data speeds of up to 384 kbps. 
>
>"Given the amount of money that wireless service providers have spent on
spectrum licenses for both fixed and mobile applications, these SkyTower
tests should be of great interest," Hindle said. "Imagine launching a
single platform, having instant metropolitan-wide market coverage, and
eliminating the terrestrial costs associated with tower build-outs and
backhaul." 
>
>The SkyTower platform connects users within its footprint of 30 to 600
miles in diameter to one or two gateway stations on the ground that can be
tied directly into a central switch/fiber optic backbone. Hindle said,
"What this means for business and consumer users is dramatically lower
service costs. For instance, SkyTower, based on analyses completed with
telecom service providers and system developers, projects that the capital
cost per subscriber to deploy a fixed broadband system, including redundant
back-up platforms, is a fraction of the cost of other alternatives such as
cable, DSL and satellite." 
>
>He added that small, low-cost, stationary user antennas can be used due to
the unique tight turning radius of the aircraft, which makes it appear
geostationary from the ground. The platform's closer proximity to earth
enables much higher frequency reuse than satellites, resulting in more than
1,000 times the local access capacity compared to a geostationary
satellite. Multiple stratospheric platforms can serve the same area,
further reusing the same frequency spectrum and multiplying system
capacity, he said. 
>
>World Altitude Record Shattered 
>
>The Pathfinder-Plus 121-foot wingspan, solar-powered aircraft, is a
smaller version of AeroVironment's 247-foot wingspan Helios aircraft which,
during NASA testing in Hawaii last summer, shattered the world altitude
record for non-rocket powered aircraft by flying to 96,863 feet - well
above the 60,000 to 70,000 feet targeted for commercial telecom services.
As part of the NASA development program, multi-day flight capability will
be demonstrated next year with the Helios solar/electric airplane using the
world's first fuel cell based aircraft energy system that enables the
aircraft to operate through the night. 
>
>Production versions of Helios unmanned aerial vehicles (UAVs) using
AeroVironment's fuel-cell-based energy systems will have flight durations
between landings of up to six months or more.
>
>SkyTower was formed by AeroVironment two years ago to pursue commercial
telecom access advantages enabled by AeroVironment's solar-electric
aircraft technology. SkyTower is one of several new businesses launched
based on the performance and economic advantages of AeroVironment's
breakthrough technologies in the areas of UAVs and efficient energy
technologies. 
>
>Broadband Battlefield Communications 
>
>"In addition to commercial interest in SkyTower's telecommunication
infrastructure, there is strong and growing government interest in
AeroVironment's UAVs, especially given the current defense needs," said Tim
Conver, AeroVironment's chief executive. "Government interest ranges from
broadband battlefield communications to emergency backup telecom services." 
>
>NASA and AeroVironment have worked together for years in the development
of the solar-electric aircraft technology. In September, NASA will be
sponsoring an agricultural remote sensing mission, using the Pathfinder
Plus aircraft equipped with multi-spectral imaging equipment to conduct
several studies including demonstrating how crop yields could be optimized
by identifying factors such as the optimal time to harvest, required
changes in irrigation levels, and outbreak of crop disease.
>
>The CRL and TAO divisions of the Japanese Ministry of Telecommunications
have been leading international advocates of using stratospheric platforms
as a low-cost, high-capacity means to make the most efficient use of scarce
frequency spectrum. Hindle said they have been instrumental in securing
international frequency spectrum allocations for what is now classified by
the International Telecommunications Union as High Altitude Platform
Stations (HAPS). 
>
>With funding from CRL and TAO, a consortium of Japanese manufacturers
including NEC and Toshiba developed the communication systems carried by
Pathfinder-Plus for the HDTV and IMT-2000 testing and Fuji Heavy Industries
integrated the payloads for their stratospheric flights.
>
>SkyTower and AeroVironment have been working closely with domestic and
international regulatory bodies to obtain the approvals required to provide
telecommunications services from a platform in the stratosphere.
Authorization was obtained from the Federal Communications Commission to
support the telecom testing this summer, and all flight tests in controlled
U.S. airspace are authorized by the Federal Aviation Administration.
SkyTower believes that the platform's extremely lightweight and
environmentally benign characteristics, combined with its highly efficient
use of frequency spectrum and energy, help facilitate favorable regulatory
support. SkyTower plans to launch the first commercial service, fixed
wireless broadband infrastructure, within three years, and is in advanced
discussions with multiple domestic and international service providers
interested in SkyTower's revolutionary "last-mile" (local access) solution.
>
>
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