Friday, March 11, 2005

Broadband In Space

Finding it hard to get broadband Internet service at your location? Look to the skies! More and more broadband services are beaming your way from above.

We normally think of broadband in terms of DSL, Cable Modem service, WiFi, Point to Multipoint Wireless, or T1 Dedicated Lines. In heavily populated areas, you may have your pick of these technologies. Your selection can be based on cost, speed, reliability and vendor preference. But what if nobody offers high speed data service in your area?

Satellite Internet and business data services are viable options today and will be even more so in the future. To see why, go outside and look up. What do you see? Nothing? That's it! The beauty of aiming an antenna upward is that there is nothing to get in the way. On the ground, there are all sorts of pesky trees, tall buildings, mountains, water towers and other obstructions to get in the way of wireless transmission. The curvature of the Earth comes into play over long distances, which is one reason why you can't beam microwaves from coast to coast, or even across state without relay towers. Satellites have no trouble with signals that have traveled 22,300 miles from the ground.

Of course all these obstructions don't faze wireline services such as DSL, T1, and Cable. Or do they? The cost of the cables is the cheap part of building out wired services. It's the cost of running the wires, hanging them from poles, burying them in the ground and the cost of getting a right of way to do so that adds up. In areas of low population density there may by nobody who wants to bear the expense of pulling cables or putting up a tower.

That's the attraction of space and near-space. Anyone in a satellite's footprint can get service if they have a clear view of the bird. It doesn't matter how many or how few other people are also pointing their dishes to the sky in the same area.

DIRECWAY is a popular consumer broadband satellite service. It costs $60 to $100 a month depending on how much you want to pay up front for the ground station equipment. For that you get download speeds up to 500 Kbps and upload speeds up to 50 Kbps. This asymmetrical upload/download bandwidth is suitable for Internet access such as email and web surfing.

MegaPath Satellite Service (MSAT) is oriented toward business users and can provide up to 1 Mbps down and 192 Kbps up. It also comes with a service level agreement guaranteeing 99% uptime. MSAT service is targeted to Internet access, point of sale terminals, credit card authorization, and so on.

Both of these satellite services fall into the category of VSAT or Very Small Aperture Terminal. That's typically a dish about 2 1/2 to 3 feet in diameter (1 meter) up to 2 or 3 times that size. These dishes easily mount on the roofs of homes, businesses and even vehicles.

VSAT equipment uses the C band (4/6 GHz) or the Ku band (12/14 GHz), with the smaller dishes using satellites on the Ku band that is shared with digital satellite TV. The next move is to the Ka band at almost twice the frequency (20/30 GHz). Internet service using the Canadian Anik F2 satellite will be available later this year from WildBlue Communications. The Ka band offers wider bandwidths but the higher frequencies are more easily blocked by rain.

Inmarsat is launching a constellation of three I-4 satellites this year that will cover the globe with over 200 spot beams each. These are the largest communications satellites to date, weighing in at over 13,000 lbs. They'll operate in the C band and L band (1/2 GHz) to provide data speeds up to 432 Kbps. This Broadband Global Area Network (BGAN) will serve land based stations, aircraft and ships.

Of course, you don't really need to go all the way into space to get the advantages of overhead transmission. The Sanswire Stratellites, automated blimps acting as Wireless Internet Service Providers, will hover in the stratosphere at 65,000 feet with coverage of cities, counties and even states. You can read more about this technology in my article, "Your Next ISP Is a Blimp."

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