 |
 |
Alumnus Helps Streamline Personal Telecommunications
 The
ICO Satellite System. Hughes technicians work on the bus module
and two of the six payload elements: the active receive antenna
and the forward transponder modules.
Virginia Tech alumnus Randy Persinger (BSEE, '76, MSEE, '78)
is de facto chief engineer for a satellite program that could
streamline personal telecommunications-giving customers the ability
to use one telephone, one number, any time, anywhere.
As ICO deputy program manager for Hughes Space and Communications
Co., Persinger has been overseeing the development of a 12-satellite
system for ICO Global Communications that will provide mobile,
handheld cellular communications anywhere in the world.
Dual-Mode Global Mobile
Slated for start-up in the year 2000, the ICO communications
system is designed to provide services to dual-mode (space/terrestrial)
cellular telephones. The system will offer digital voice, data,
and facsimile services, as well as a range of messaging services.
"With the ICO system, customers could use their phones via
terrestrial operation where service is available, then switch
to direct-to-satellite mode if they are hiking in the mountains,
rock climbing, or travelling in areas without a cellular network,"
Persinger said. "Same phone, same phone number," he
added.
The satellite system will consist of 12 operational satellites,
each supporting 4,500 telephone channels, operating for 12 years
in medium earth orbit at an altitude of 6430 miles. The orbital
constellation is designed for significant coverage overlap, so
that two-but sometimes three or four-satellites will be in view
of a user any time.
First Medium-Earth Orbit System
The satellites will be the world's first commercial medium-earth-orbit
system. For Hughes, the more than $2 billion system also provides
several significant firsts: it is the largest commercial job
in the company's history; it is an all-new design; it is the
first time the company is building 12 identical spacecraft.
The satellites' new design uses digital signal processing (DSP)
to create and route the beams, which has not been done before
in a commercial system.
"Each satellite has two large, direct radiating arrays-each
with 127 element chains. It's a lot of hardware," Persinger
said.
"It's been a challenge designing and integrating all that
hardware over extreme operation environments and testing it.
We have a lot more individual boxes than most spacecraft."
The ICO satellites also differ from most other spacecraft in
their degree of modularity-from the payload panel to the DSP
slices, whose microchips are laid out in compact groups to minimize
size and power draw. "It's like a giant Lego™ model,"
Persinger said. "Elements can be worked on separately and
then assembled-the advantage is that work can advance on each
of the elements simultaneously."
Cradle-to-Grave
Persinger has been involved in the project from its very beginning.
He was involved in the original studies of the concept six years
ago, helped win the job for Hughes, led the design team, and
now is overseeing production. "It's not often you get to
start out with a blank piece of paper and follow a project through
to completion," he commented. "The thrill now is that
it's real. You can go into the factory, see, and test it."
Hughes awarded Persinger the Chairman's Marketing award in 1995
in recognition of his efforts to win the contract.
Persinger has spent his career in satellite communications. After
earning his master's degree, he worked for a short time for Hughes
Aircraft, as the company was then called. He then moved east
and spent 14 years with COMSAT-including a stint in Cannes, France.
At COMSAT, he worked in satellite launching, design, and customer
consulting, traveling extensively throughout the world.
He rejoined Hughes in 1993, bringing a customer perspective to
his work there.
Persinger grew up in Newport News, Virginia and earned his BSEE
at Tech, while co-oping at Virginia Power and Electric Company.
During a summer class with Charles Bostian, he became interested
in electromagnetics and antenna theory. He then changed his concentration
and studied antennas with Warren Stutzman.
"Bostian and Stutzman changed my career," he said.
"With their support and encouragement, I stayed for my masters
and was one of the original crew at Tech's Satellite Tracking
Station.
"Looking back on my career, I'd say that Virginia Tech gave
me the fundamentals, and a strong foundation that enabled me
to advance quickly in industry."
|
