Satellite Radio: What Is It?

By Owen Jones

Satellite radio has actually been around for quite some time, but it was inaccessible to many people because the stations that were broadcasting were fairly obscure, the apparatus was costly and the antennas, normally in the form of dishes were extremely directional, which meant you needed to use expensive, skilled installers.

For proof of this you should look no further than bookmakers and betting shops who had specialized satellite broadcasts beamed to their establishments with the results of the races live.

The difference now is in cost and the power of the satellite radio transmission devices as well as the receivers. In other words, satellite radio technology has advanced a long way since the Eighties. Satellite radio can also be received more easily nowadays, although the reception of satellite TV broadcasts still necessitates a directional receiving dish. This is why satellite TV cannot be received well on a boat or in a car, but you can still get satellite radio and you can still use your mobile phone.

Satellite radio broadcasts are digital so most of the benefits of using it are linked with digital technology. Some of these are: the ability to pick up signals from all around the wold through the satellite network and the lack off interference - that annoying hiss that you often got at night while listening to a distant broadcast. Reception is now consistently crystal clear owing to the uncomplicated rythym that is digital - on and off or high and low.

Digital only makes use of two signals so they are impossible to mix up, whereas analogue had millions of them allowing for mistakes due to bad weather or / and bad equipment. That has been largely eradicated.

The state of affairs in the US is that there is still competition between two contrasting systems: XM and Sirius and it is to be hoped that this situation will soon be resolved as it was thirty years ago between VHS and Betamax, because otherwise it will only be the public who lose out in the end - the clients of the firm that goes bankrupt.

There were initially problems with satellite radio in some areas because natural or man-made structures would block the line of sight from the antenna or dish to the satellite causing a break in transmission. Typical causes for this would be tunnels, mountains and sky scrapers.

However, the satellite radio service providers soon came up with a solution to the problem by bouncing the signal from the airborne satellite off terrestrial dishes, in other words, reflecting them at closer to ground level, thereby providing satellite radio to millions of inner city dwellers.

About the Author:

Owen Jones, the writer of this article, writes on a range of subjects, but is currently involved with Bose alarm clocks. If you would like to kcurrently more, please visit our website at Bose Digital Radio.

Satellite Radio Technology

By Owen Jones

Satellite radio technology is the equivalent of cable or satellite television and it is certainly here to stay. There are several reasons for this: the quality of the broadcasts is higher, the quality of the apparatus's reception is higher and the general coverage of the station, that is to say the so-called satellite's footprint is far greater too.

This has the effect that if you travel long distances, you will be able to stay with the same channel without having to look for a new one every forty or fifty miles as you need to do with AM or FM radio stations.

In order to reach this quality, the recording and playback speed needs to be around the 384 kbps level. The music tracks are catalogued in a similar way to the MP3 system, which uses names called ID3 tags.

Each channel on satellite radio endevours to establish its own identity. A music channel might try this by playing music only of one type or from only one period or decade. This means that you may get a satellite radio station called 1970's Punk music or Twentieth Century Classical Music.

On some stations, the music controller or disc jockey will choose, say, fifty minutes worth of music, will listen to it in order to ascertain that the quality and the order are correct and then let the computer play it over the airwaves. This leaves ten minutes every hour for the news and then the sequence can be repeated automatically.

Satellite transmission uses digital recordings and each channel is encoded on a different frequency. Similarly, each decoder, say, in your car or your home needs to recognize and decode each station separately too. This coding and decoding is done extremely quickly, in fact in what is referred to as 'real time'.

The resulting binary or digital code is then turned into into analogue signals so that your speakers can replay it. This process produces sound which is just about of CD quality.

The broadcasting satellites are in a geo-static orbit at 23,000 miles above the Earth and have a large footprint which is the name given to the region of ground that is capable of receiving their broadcasts.

In America, for example, the two areas concentrated on at first were the densely populated east and west coasts in order to maximize possible income. One satellite would be incapable of covering the whole of the United States in that orbit.

In order to receive satellite broadcasts, you will have to use a special antenna on your decoder. This antenna must be capable of picking up L-band broadcasts for it to be of use.

These new antennas are a big improvement on the satellite dishes (similar to those used for satellite TV) that one used to have to have in order to take advantage of satellite radio technology

About the Author:

Owen Jones, the author of this piece, writes on a range of subjects, but is now concerned with Bose radio alarm clocks. If you would like to know more, please go to our web site at Bose Digital Radio.