By John Blau
IDG News Service
April 12, 2007
The U.S. military plan to test an Internet router in space, in a project
that could also benefit civilian broadband satellite communications.
Cisco Systems and Intelsat General, a subsidiary of Intelsat, are among
the companies selected by the U.S. Department of Defense for its
Internet Routing In Space (IRIS) project, which aims to deliver military
communications through a satellite-based router.
Potential nonmilitary benefits of the IRIS program include the ability
to route IP (Internet Protocol) traffic between satellites in space in
much the same way packets are moved on the ground, reducing delays,
saving on capacity and offering greater networking flexibility, Lloyd
Wood, space initiatives manager in the Global Defense, Space & Security
division of Cisco, said Thursday.
To send a message from one remote terminal to another via satellite
today requires the first terminal to send the data to the satellite,
from where it is bounced back to an earth station for routing. The earth
station retransmits it to the satellite on a different frequency,
selected depending on its destination, and the satellite bounces it back
to its destination. With the router in space, the satellite can pick the
channel used to send the message to its destination. By eliminating the
message's round trip to the earth station, operators can increase
satellite capacity and reduce transmission times between remote
terminals by using fewer hops and fewer frequencies for each message.
For the IRIS program, satellite operator Intelsat will manage the
three-year project, with Cisco will provide IP networking software for
the on-board router.
After testing, the technology will be available for commercial use.
Although satellites have been passively relaying IP traffic since the
1970s, the use of an orbiting satellite as an active part of the
Internet is a more recent development, according to Wood.
Traditionally, communication signals that come up to a satellite in
either the C-band or the Ku-band, go down in the same band, he said.
They require separate transponders that don't communicate with each
Internet routing technology being tested in the IRIS project will enable
this communication by "decoding what comes up in the C-band or Ku-band
and interconnecting the two," said Wood.
"You save on delays and capacity by not having to go back to the
ground," said Wood. "And once you have smarter satellites, you can treat
them as not completely separate but as part of your IP network and
manage them as you do your IP networking assets on the ground. They
become fully integrated with your terrestrial network, allowing you to
take advantage of existing management tools and also decrease the number
of ground stations."
The IRIS payload will support network services for voice, video and
data. The system is designed to support IP packet Layer 3 routing or
multicast distribution, which can be reconfigured on demand.
The Defense Information Systems Agency will have overall responsibility
for coordinating the use of IRIS technology among government users and
leveraging IRIS capability once the satellite is in space.
The satellite is set for launch in the first quarter of 2009.
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