Sirius Radio - Everything You Ever Wanted to Know

Sirius radio, or more generally satellite radio, came out just a few years ago. If you've never listened to satellite radio or heard about it, this article is your lucky break.
What Is Satellite Radio?

Just like the name indicates, satellite radio uses satellites and related equipment to broadcast radio channels to car or home radios. The concept really received its impetus in 1992 when the FCC set aside a chunk of radio frequency for what they called Digital Audio Radio Service (DARS).
Five years later, Sirius Radio and XM Satellite Radio purchased licenses from the FCC, and both companies started putting the pieces into place to be able to start broadcasting.

Conventional radio waves can only travel 35 to 45 miles before they die out. The signal for satellite radio services is broadcast more than 20,000 miles above the Earth's surface.
Programming on satellite radio is subscriber based, meaning you pay a monthly fee to descramble the signal from the satellites. But, most satellite radio service comes commercial free, so you don't have to worry about channel hopping. Channels include music, talk radio, sporting events, kids programs, and news.

The Who's Who of Satellite Radio

There are currently three major players in the satellite radio game: Sirius radio, XM satellite radio, and WorldSpace.
Sirius radio covers North America, including the continental U.S., Canada, and Alaska. XM provides service in the continental U.S. WorldSpace is developing coverage in other parts of the world (Asia, Africa, Europe, and South America) and are definitely the most ambitious in terms of client coverage (a potential of 4.6 billion clients covered on 5 different continents).
Each company uses different satellite technology and methods to provide service in their respective areas.

Satellite radio equipment, such as car receivers and home stereos, are sold at a variety of consumer electronic stores, and are starting to become standard installations in new cars.
Conventional radios cannot receive satellite radio transmissions, so picking up the service usually entails purchasing a receiver, though some kits are available to make conventional radios satellite-radio compatible.

Because of the different technology each company utilizes, receivers are not compatible with every company. For example, if you subscribed to XM but then wanted to switch to Sirius radio, you would need to get a new receiver that was compatible with Sirius.
Some satellite television companies include satellite radio service in their channel packages, and you can receive the transmission through your television satellite dish.

How Does Satellite Radio Work?

This is the cool part. The music, talk show, sporting event, etc., are recorded digitally in a studio, after which the message is encoded. The encoded signal is sent to the satellites from ground stations (Sirius radio based in New York; XM based out of D.C.).
The satellites then relay the signal to receivers in your car or at home. The receivers contain chipsets that decode the signal and play it through you stereo. In urban areas where taller buildings might block the signal from the satellites, ground repeaters or transmitters are used to resend the signal, eliminating pockets of dead space.

XM uses two satellites to cover the continental United States with their signal. Sirius radio uses three satellites to form a satellite constellation.
The way they are set in orbit ensures that each satellite spends about 16 hours at a time covering the U.S. and that there is always at least one satellite over the U.S. at any given time.
WorldSpace satellites beam three signals each to increase the amount of territory they are able to cover with their three satellites. All three companies have reserve satellites ready to launch in case one of their satellites stops working.