This Electronics Engineering Seminar Topic deals with the following:
We all have our favorite radio stations that we preset into our car radios, flipping between them as we drive to and from work, on errands and around town. But when travel too far away from the source station, the signal breaks up and fades into static. Most radio signals can only travel about 30 or 40 miles from their source. On long trips that find you passing through different cities, you might have to change radio stations every hour or so as the signals fade in and out.
Now, imagine a radio station that can broadcast its signal from more than 22,000 miles (35,000 kill) away and then come through on your car radio with complete clarity without ever having to change the radio station.
Satellite Radio or Digital Audio Radio Service (DARS) is a subscriber based radio service that is broadcast directly from satellites. Subscribers will be able to receive up to100 radio channels featuring Compact Disk digital quality music, news, weather, sports. talk radio and other entertainment channels. Satellite radio is an idea nearly 10 years in the making. In 1992, the U.S. Federal Communications Commission (FCC) allocated a spectrum in the “S” band (2.3 GHz) for nationwide broadcasting of satellite-based Digital Audio Radio Service (DARS).. In 1997. the FCC awarded 8-year radio broadcast licenses to two companies, Sirius Satellite Radio former (CD Radio) and XM Satellite Radio (former American Mobile Radio). Both companies have been working aggressively to be prepared to offer their radio services to the public by the end of 2000. It is expected that automotive radios would be the largest application of Satellite Radio.
The satellite era began in September 2001 when XM launched in selected markets. followed by full nationwide service in November. Sirius lagged slightly, with a gradual rollout beginning _n February, including a quiet launch in the Bay Area on June 15. The nationwide launch comes July 1.
To the average user, these systems will look very similar to conventional AM/FM .radio systems, whether they are used in the home, office, or on the road. However. the real difference is in what the listener won’t see. Rather than receiving a signal from a tower antenna of a local radio station, these new radios will receive signals from a set of satellites in geosynchronous orbit. Programming will be up linked from ground stations to the satellites and then broadcast back to large geographic areas.
The programming will be up linked to the three geostationary orbit satellites and then rebroadcast directly to radios in the vehicles of CD Radio subscribers. Ground based repeaters will be used in urban areas to provide a clear and uninterrupted radio signal.