Networking in th e 21st Century: The Sky's the Limit

	High Hopes, High Hoops In many ways, high-stakes broadband satellite survival will be an incredible endurance run, with many hoops and obstacles. Among them: --Complexity. Next-generation systems rely on new technologies, such as intersatellite links, that aren't yet fully tested. New systems, like LEOs and MEOs, may also add new problems, such as jitter, as they seek to address old issues, including latency (See sidejitter, side latency). Modeling is important, but the real answer s seldom come until equipment is deployed. Even billing issues can be huge, since these systems will need to pioneer new global invoicing processes. --Regulation. Obtaining satellite spectrum is a multiyear process that can involve different criteria on the parts of the FCC and ITU. And spectrum approval doesn't spell the end of the process. Approvals don't necessarily mean a provider gets first dibs on the spectrum, so satellite providers may end up with secondary rights to frequencies already approved for another provider (adding technical complexities to service provisioning). In addition, providers in individual nations may already have approval to use the spectrum. Following international approvals, global providers must negotiate with individual nations and their service providers to initiate service in those countries and obtain rights to the frequencies. --Security. U.S. export restrictions and international policy restraints make it difficult for satellite providers to protect critical manag ement, billing and control information over frequencies than can readily be picked up by intruders. User reliance on IPSec end-to-end encryption and authentication is also problematic in GEO systems that rely on TCP spoofing to reduce latency (See SideSEC). --Funding. Most satellite systems are billion-dollar ventures with the bulk of funding required upfront without any guarantee of success. To survive, companies need deep pockets or deeper alliances. All this means long planning cycles--which aren't exactly advantageous when most terrestrial service providers are operating on Internet time. LEO systems present additional funding issues because the full constellation must be launched before service can begin, many more satellites are required, and these satellites are (constellations must be much larger to cover the globe and are ) expected to burn up in about five years-about half the life cycle of GEOs. That means LEO constellations will be more expensive to maintain, especially in terms of having read y-to-operate spares already in orbit (See sidegeoleomeo). --Launch vehicle and site shortages. Today, only a handful of sites are used for launching commercial satellites-- the Kennedy Space Center at Cape Canaveral and Vandenberg Air Force Base; Kourou Cedex in French Guyana; Jiuquan, Xichang, and Taiyuan in China, the Baikonur Cosmodrome in Kazakhstan; Plesetsk in Russia; Sriharikota in India; and Tanegashima in Japan. New sites, however, have recently come online or been approved including spaceports in Florida, California, Virginia and Alaska; Norway; Sweden; Australia and Brazil. --User satisfaction and transition. A Forrester Research report shows substantial dissatisfaction with existing services among current satellite users. Most users aren't contemplating increasing satellite services, know little about next-generation systems and have serious reservations about satellite reliability (like how they will get service if a GEO fails.) Users also want to know how quickly spares can be put i nto service in the event of a failure. --Lack of standards. The fact that most satellite systems are proprietary is driving up costs. It's difficult, too, to use off-the-shelf components in satellites because of radiation and high-reliability requirements (mandated by the difficulty in making fixes once a satellite is launched). There is concern, for example, about the difficulty in building this kind of reliability into complex systems like onboard switching. --Space junk. Meteor storms (like the once-every-30-years event to occur this summer) and space debris are the astral equivalents of the terrestrial backhoe. Because of their high-speed orbits, a single bolt colliding with a satellite could turn that satellite to worthless liquefied plasma. There has even been a suggestion that a collision could set off a cascade effect among multiple satellites, although more recent data suggests this is not likely.

For the Side Bar on LEOs Dance The Jitterbug GEOs Turn Up The Speed Of Light You Say GEO, I Say LEO, Oh My, Oh MEO The Big Five Planned Constellations Do LEOs Have Too Much Latency? A Q&A With Teledesic Mobile Voice Blazes an Astral Trail for Broadband Other Features Slicing Through the Hype of IP Switching By Joel Conover