A radio relay station in orbit above the earth that receives, amplifies and redirects analog and digital signals contained within a carrier frequency. There are three kinds. Geostationary (GEO) satellites are in orbit 22,282 miles above the earth and rotate with the earth, thus appearing stationary. The downlink from GEOs back to earth can be localized into small areas or cover as much as a third of the earth's surface.
Low-earth orbit (LEO) satellites reside no more than 1,000 miles above the earth and revolve around the globe every couple of hours. They are only in view for a few minutes, and multiple LEOs are required to maintain continuous coverage. Medium-earth orbit (MEO) satellites are in the middle, taking about six hours to orbit the earth and in view for a couple of hours. See Teledesic, Iridium, DSS, DirecPC and bent pipe architecture.
Communications Satellite
There are hundreds of commercial communications satellites in orbit providing services for both industry and consumers.
Low-earth orbit (LEO) satellites reside no more than 1,000 miles above the earth and revolve around the globe every couple of hours. They are only in view for a few minutes, and multiple LEOs are required to maintain continuous coverage. Medium-earth orbit (MEO) satellites are in the middle, taking about six hours to orbit the earth and in view for a couple of hours. See Teledesic, Iridium, DSS, DirecPC and bent pipe architecture.
Communications Satellite
There are hundreds of commercial communications satellites in orbit providing services for both industry and consumers.
 | Reproduced with permission from Computer Desktop Encyclopedia. Copyright (c) 1981-2008 The Computer Language Company Inc. All rights reserved. |
Additional Resources
- NSA and phone sex: Eavesdroppers listened to intimate conversations
- Military linguists have come forward to say that the intelligence services routinely listened in on Americans overseas calling home and on the communications of non-suspect groups like the Red Cross. And, they say, they listened in and even transcribed couples' phone sex, The New York Times reports. ...
- Blog posts 2008-10-10
- America's airways ready for NextGen
- It's time – long past time – to upgrade the U.S. air traffic control system. The current system, designed during World War II, contributes mightily to flight delays, customer dissatisfaction and a massive energy wastefulness. But a GPS satellite-based system, on the drawing board for more than a decade, has...
- Blog posts 2008-10-10
- Laptops with mobile WiMax now available
- The first laptops with built-in mobile WiMax wireless broadband are now available in the U.S. Sprint, Intel and the computer companies announced the new WiMax configurations at an event in Baltimore just a few days after Sprint launched its Xohm service there. All of these laptops use...
- Blog posts 2008-10-09
- Palin the reformer? In fact, a pattern of stonewalling and hiding
- The Associated Press takes a hard look at Sarah Palin's spotty – perhaps, hypocritical – record on open government and online transparency. She claims to be a reformer who will bring to Washington the government openness she says she established in Alaska. But the AP's review of her...
- Blog posts 2008-10-08
- Where are all the programmers?
- I was at a conference Wednesday that covered an awful lot of ground. There were some good sandwiches, too, and the cookies were first-rate. One thing that stuck out in my mind, though, aside from the deserts, was one companies inability to hire good programmers domestically. This...
- Blog posts 2008-10-08
- Palin e-mail hacker indicted, pleads not guilty. Is justice being served?
- Justice is being served against the kid who allegedly hacked into Republican VP candidate Sarah Palin's Yahoo email account, right? David Kernell, the 20-year-old son of Democratic Tennessee state representative Mike Kernell and a student at the University of Tennessee, was indicted on a charge of accessing...
- Blog posts 2008-10-08
- Mail Goggles: an idea that goes well beyond drunk emails
- There's a new GMail Labs app: Mail Goggles, by GMail engineer Jon Perlow: When you enable Mail Goggles, it will check that you're really sure you want to send that late night Friday email. And what better way to check...
- Blog posts 2008-10-08
- Cisco SONA
- Cisco caught my attention by asking me if I wanted to see the results of a study indicating how organizations are seeing Web 2.0 and/or Service Oriented Architecture SOA application adoption. Having executed dozens of studies of this nature while I was at IDC, I was interested in the results,...
- Blog posts 2008-10-08
- Measuring the Pain: What is Fragmented Communications Costing Your Enterprise?
- In this document, you will discover the results of the largest-ever survey of enterprise and contact center employees. Their workflows reveal the silent but staggering costs of fragmented communications. In fact enterprises with 1000 plus employees could be losing more than £6 million a year. ...
- White papers 2008-10-08
- ITIL - Service Approach for Siemens Enterprise Communications
- The structure of ITIL is evolving from Version 2 to Version 3; understand how the adoption and application of the ITIL framework can add value to your enterprise, and how Siemens is taking the ITIL model and using it to drive portfolio and proposition development, alongside global service delivery capabilities....
- White papers 2008-10-08
- Blogger ethics, public relations... and you
- Two different conversations that are connected at the core by the way the news media continues to grow and change. Bloggers have a significant responsibility in wielding their keystrokes, whether they have 10 readers or 10,000. Public relations professionals are still grappling with how to best work with this new...
- Blog posts 2008-10-07
- Future wireless networks could be powered by "smart lighting"
- Future wireless networks could be powered by "smart lighting"No not really..As interesting as the technology sounds - it wont fly, until they get the data rates up. Even though the technology seems to be off for another 10 years - we'll still have radio communications for many, MANY years after...
- Discussion threads 2008-10-07
- Future wireless networks could be powered by "smart lighting"
- A light bulb went off in the head of researchers at Boston University about a new wireless networking technology, which was very appropriate considering that it involves, well, light bulbs. The Smart Lighting Engineering Research Center has been created to develop technology that would allow low-powered...
- Blog posts 2008-10-07
- Live Webcast: The 2008 Email Security Benchmarking Report
- Email is a critical tool for business communications, but its use is threatened by the growing volume and sophistication of external attacks. Today's best-in-class organizations are realizing significant benefits compared to other organizations, particularly through the use of Software as a Service SaaS security applications. Join this...
- Webcasts 2008-10-07
- ZDNet blogger: working from home
- More and more people work from home every day. Not only that, more and more people don't work from their offices, or "where they're meant to work". With the Internet, intranet's and extranet's, email and unified communications with VoIP and Blackberry devices, it makes life much easier...
- Blog posts 2008-10-06
- Samsung HT-X710T
- We recently looked at the HT-TZ512T from Samsung, a solid home theater-in-a-box that focuses on DVD playback and offers wireless rear surround sound. The TZ512 also offers a few additional audio inputs as well as compatibility with various digital file formats. The HT-X710T, reviewed here, keeps most of...
- Product reviews 2008-10-06
- Improve your failed IT culture
- Improve your failed IT cultureRisk and rulesWhat's the connection between your suggested steps to improve projects and the problem identified?Is it possible to deal with the problem identified in the following quoted quotes without using the word "blame"?Creating a culture for risk management is a challenging proposition for most firms....
- Discussion threads 2008-10-06
- Why bother with desktop virtualization?
- Why bother with desktop virtualization?PortabilityNo matter where you are, there you are.Sit down at a workstation and light up your working environment. No need to drag the hardware with you, which ranges from annoying to hazardous, what with laptops being popular targets for confiscation at airports. Especially since...
- Discussion threads 2008-10-06
- Why The Big Fuss Over Microblogs?
- I microblog.Why? The truth is, I learn by doing and by speaking with others who do. So I dabble with Twitter, Plurk, Pownce, Spoink, Rakawa, Tumblr, Utterli, Yammer, FriendFeed, 12seconds, and probably a few others that I signed up for and forgot to use. I have found a nice collection...
- Blog posts 2008-10-06
- Two Europeans indicted for US cyberattacks
- The indictments are part of the FBI's Operation Cyberslam, said to be the US's first successful investigation into a large-scale, commercially motivated denial-of-service attack Two Europeans, one of whom is English, have been indicted by a US federal grand jury in connection with a 2003 distributed denial-of-service attack that...
- News items 2008-10-06
Neighboring Terms
Premier Vendor Content Whitepapers, webcasts & resources from our Power Center Sponsors
- BNET Industries
- Check out BNET's newest resource for managers and executives. Need to do research on your competitors? Don't have time to read every trade pub? BNET Industries is the new source for daily news, insights, and research on 11 major industries and 9,000 public companies.
-
- The technology industry from a different angle
-
- See what's hot in the auto industry
-
- Stay on top of the energy industry
