If he could start with a clean slate, Cisco’s Rick Sanford says he would design a global communications system that would use Internet Protocol (IP) to seamlessly network communications systems from the ground to geostationary orbit — and beyond.
He is the first to admit there is no clean slate, but Sanford, director of Cisco’s Global Defense and Space group, and his company have a vision for the way commercial and military satellite systems could look in 15 years.
Sanford advocates using an IP-based router on satellites in conjunction with inter-satellite links that connect satellites in orbit to each other as well as connecting them to the ground. Additional routers on the ground would provide interconnectivity to all kinds of systems.
Intersatellite links can connect satellites in orbit by either using optical laser links or radio-frequency-based transmissions such as those designed for the Iridium constellation of low-Earth-orbiting satellites. Iridium is a constellation of 66 satellites that provide data and voice communications for users of handheld devices. Each satellite has four intersatellite links allowing it to communicate with two satellites behind it and two satellites in front of it in the same orbital plane.
In Cisco’s vision, intersatellite links could potentially even connect low-Earth-orbiting satellites with satellites in geostationary orbit.
Optical lasers, considered a potential driving technology for the U.S. Defense Department’s Transformational Communications Satellite (TSAT) program, are still in the development stage.
U.S. Strategic Command is currently funding a study by Cisco and PanAmSat of Wilton, Conn., to determine the feasibility of equipping PanAmSat’s planned PAS-14 satellite with a router and intersatellite links.
This IP and intersatellite concept would take some of the intelligence out of satellite ground systems and put it into space.
“The case for IP routing and IP technology in space is to allow that satellite through its links to play an active part in the network,” Sanford said. “It helps mitigate against some of the same risks that folks who don’t believe routing in space was appropriate are arguing against.”
When those capabilities are placed only on the the ground systems, users theoretically would need to have fiber running across the entire planet to be guaranteed an Internet connection in all places, Sanford said. “If you can guarantee that from any ground station, you can provide services to any endpoint anywhere on Earth, then yes, it is easier to have intelligence on the ground.” But by using routers and links to put intelligence on the satellite, it lowers the number of ground stations that are necessary, which can lower costs to dramatic effect, he said.
” Today in the commercial satellite world, you may have a situation where there are 11 ground terminals which operate two constellations,” Sanford said. “If we’ve got cross-links in space with proven technology, we might not need 11 ground stations. Maybe we need five.”
While some individuals in the military community and elsewhere consider the use of Internet Protocol for satellites a potential security risk, Sanford believes a lot of the risks can be alleviated if commercial companies work in partnership with independent verification providers or government organizations.
“The notion of ‘Well, it’s not robust enough for government, it’s too risky’ — I counter that today on Wall Street, there is something like $40 trillion a day worth of financial transactions which go across a commercial network,” Sanford said. “In fact, our most security-conscious, robust customers are on Wall Street.”
Critics also have said that there are issues with timing delays when intelligence is in space rather than on the ground. Sanford believes that this is because those who talk about the issue focus on a specific type of protocol known as Transmission Control Protocol/Internet Protocol, which is not how Sanford believes the networks should be run.
“There are literally hundreds of different types of network protocols run on IP infrastructure,” Sanford said, noting that some that exist today are specifically configured to tackle the sort of delay problems satellites could potentially experience.
Resistance to IP-based technology comes from a culture where reverse-engineering is more common than starting from scratch, and where the existing architecture in place keeps hundreds of people employed, Sanford said.
Sanford said the U.S. government needs to stop building space systems with only certain program requirements in mind and start designing systems in a way that makes it easier to adapt to new capabilities that will be desirable in the future.
Both Cisco and the U.S. government already have begun to put dollars behind these ideas. U.S. Strategic Command is investing $475,000 in the study looking at putting the intersatellite links and an IP router on PanAmSat’s planned PAS-14 satellite, Maj. Jeffrey Jones, chief of media relations for Strategic Command, said in an e-mail June 2. Strategic Command hopes the IP routing will allow more efficient use of bandwidth and help with latency issues, Jones said. Still undecided is whether the project would rely on laser or radio frequency technology for its intersatellite links. The study is due to be completed in July.
Cisco has partnered with five ground terminal manufacturing companies: Mobile Satellite Ventures of Reston, Va.; ViaSat of San Diego; Hughes Network Systems of Germantown, Md.; Loral Skynet of Bedminster, N.J.; and Gilat Network Systems of McLean, Va., to determine to what degree its IP architecture could provide cost savings for the companies. Sanford envisions intersatellite links as eventually even connecting satellites from different providers with each other, and low-Earth-orbiting satellites with geostationary satellites.
Cisco is funding its own study examining different ways that the performance of intersatellite links can be improved. The study is being done with the Institute for Telecommunications Research, headquartered at the University of South Australia.
According to professor William Cowley, who is leading the study, the scientists for about a year have been looking at variables such as transmission rates and antenna structure to see what gives the most effective performance using simulations to test different combinations.
Cisco also is working with the Massachusetts Institute of Technology to examine some of the cultural and political roadblocks that exist against IP in space.
“This is not a science experiment,” Sanford said. “There’s an awful lot at stake, and none of us is willing to accept failure.”
Comments: mfrederick@space.com
