How Satellite TV Works
With the cost of cable television constantly on the rise, more and more people are making the switch from cable to satellite. Perhaps you are one of those people who are at least considering it. Of course the obvious question is: “Do I really want to go with satellite instead of cable?” The satellite companies will tell you, “Of course you do!” The cable companies will tell you, “Oh no! You don’t want to do that!” And each will give you horror stories about the other. Sometimes the best way to make an informed decision is simply by understanding how something works. Once you see how satellite TV works, you can decide for yourself if it will work for you.
Satellite TV In the beginning…
Satellite dishes have come a long way since the days of huge antennas. Back then, the average antenna was twice the size of a picnic table umbrella and something only the most diehard television fan would dare use. One big advantage of the old satellite system was that it gave viewers a glimpse of a lot of things that broadcasters didn’t want people to see. Back then, dish users could watch live feed between broadcast stations, and unguarded “off-camera” moments during commercial breaks. Thanks to advancements in technology, the old days of satellite TV are over. You can’t watch the unguarded moments anymore, but then again you don’t have to set aside a huge part of your yard for a monster antenna anymore, either. Today, the average satellite antenna is no more than 18 inches across and can be mounted almost anywhere. Satellite TV is also much easier to use. It’s no more difficult than a cable TV hookup, and often much cheaper.
Satellite Dish Anatomy
A satellite dish consists of two parts: the reflector, and the feed horn. The reflector is the concave dish-shaped part of the antenna. This is the part of the antenna that captures and focuses the satellite signal onto the feed horn. The feed horn is the part of the antenna that is mounted on an arm that sticks out from the dish. It takes the signal and feeds it through a cable to your satellite receiver, the box that sits in your living room. Newer satellite dish designs feature multiple feed horns. This is so the dish can pick up signals from several satellites and clearly focus the captured signal on one of the several feed horns.
In order to provide a clear signal, the feed horn has a feature known as a low noise block down converter (LNB). The LNB does two things: It amplifies the signal received from the satellite provider, and filters out ‘signal noise,’ radio signals that do not carry the satellite provider’s programming.
Satellite Providers Such as DirecTV and Dish Network Send Their Signals Wirelessly, Just Like Broadcast TV Does
There is one signficant difference, however. Broadcast television providers send their wireless signal via land-based antenna. Antennas send their signals in a straight line. To receive the signal, you must be in an antenna’s line of sight. In other words, you have to be in a straight line from the boradcaster’s antenna.
Now here’s the problem: We live on a round planet. So, if you’re broadcasting from the ground in a straight line on a round planet, what happens? Your range is severely limited. Throw in some mountains, valleys, and those pesky skyscrapers and you only compound the problem. One solution is to build tall broadcast towers on high ground, but you can only go so high.
So how does satellite TV deal with the problem? Satellite TV eliminates the tower and limited range problem by using satellites located about 22,000 miles above earth. That’s slightly further than the trip to grandma’s house, and definitely taller than any land-based broadcast tower. Broadcasting from 22,000 miles high straight down upon a round earth dramatically increases the line of sight, meaning that the signal covers a much larger range of subscribers.
So How Does the Satellite Keep Contact With My Dish Antenna? Through the Magic of Geosynchronous Orbit.
Actually, it’s not magic at all. It’s physics. The best way to demonstrate it would be for you to try, or imagine, this little experiment:
-
- Get a bucket and tie a rope to the handle (maybe put a little water in the bucket for weight)
- Find an open area and grab the end of the rope opposite the bucket.
- Start spinning (and don’t let go of the rope!)
Notice that as you spin, the bucket more or less stays in the the same position relative to you. A satellite in geosynchronous orbit does relatively the same thing. The satellites in a satellite TV system are launched into space at approximately 7,000 miles per hour and at a distance of over 22,000 miles above the earth. At this speed and distance, it takes the satellites twenty-four hours to circle the globe. What does that mean? It means the satellites keep pace with the rotation of the earth, so like your bucket, they stay over the same spot as the earth turns. That’s nice. So what? Because the broadcast satellites maintain a geosynchronous orbit over the earth, your Dish Network or DirecTV installer just has to focus your satellite dish on one spot in the sky (where a satellite is), and that’s it.
Getting the Satellite TV Signal
Today, the average satellite TV user gets his programming from a direct broadcast satellite (DBS) provider. The two main DBS providers in the U.S. are DirecTV and Dish Network. When you subscribe to one of these providers, you get what is called a direct to home (DTH) satellite system, which consists of the following five parts:
-
- Programming sources. As the name suggests, programming sources are the sources from which satellite providers get their content. Satellite providers don’t create the actual programs you see. Like cable, they get their content from various sources like ESPN, or The HistoryChannel, just to name a couple. The satellite provider is just the medium between you and the content provider.
- The DBS broadcast center. This is where the satellite provider collects its broadcast content. That content is beamed by your provider to its broacast satellites, which in turn beam the content to your dish antenna.
- The satellites. This is the heart of the whole satellite TV concept. Traveling in geosynchronous orbit around the earth, these satellites receive signals from the DBS broadcast center and send those signals to subscriber antennas on the ground.
- The dish. The dish is the subscriber’s antenna. The dish picks up the satellite signal and sends it, using a cable, to your receiver (or box).
- The receiver. The receiver, not to be confused with the dish, is the device that decodes the satellite signal and passes it to your television.
Satellite Television is 100% Digital
This is one of the big advantages that satellite TV has over cable. Cable can offer digital TV, but not all of it’s offerings are digital. Satellite TV, because of the way it is delivered to your home, is all digital. Here’s how it works…
Satellite providers get their content from a mix of sources, both local and global. The global content comes from what are known as “turnaround” channels. They include content providers such as CNN, TLC, The Discovery Channel, The History Channel, ESPN, etc. Turnaround channels have their own geosynchronous satellites to which they beam their content. Satellite providers, like DirecTV and Dish Network, use large antennas at their DBS centers to collect this content. To get content from local channels, the process works a little differently. Local content providers typically do not broadcast their signals to satellites. To get their content, satellite providers must set up facilities in local broadcast areas and receive the signals by fiber-optic cable or antenna. From there, the content is sent to the satellite provider’s DBS center. The whole global and local package results in a mix of analog and digital signals. For satellite broadcast, all of these signals are converted into a high-quality digital stream. In order to be handled by the satellite, this stream is compressed using MPEG-2 video compression, and beamed to the provider’s satellite. Then it is sent to subscribers’ homes where the signal is decoded by the receiver, resulting in a high-quality digital image.
Some Honest Questions and Answers
-
- How does the price of satellite compare with cable? As a general rule, satellite is cheaper. Every now and again your local cable provider will come out with an offer that is cheaper than satellite, but be sure to read the fine print. Typically the lower cost is for a limited time and sometimes it comes with a long-term comittment. When it comes to content, cable and satellite are both at the mercy of the content providers. As content providers’ charges go up, so does the price of satellite and cable. Even so, satellite is still usually cheaper. At times, however, a satellite provider may opt to drop a content provider rather than raise its price. If the dropped channel is one you don’t care about, then it’s no big deal. But if it’s a channel that is one of your favorites, you might want to reconsider.
- How reliable is the signal? Given how satellite signals are received, it’s understandable how a signal might be broken, but don’t believe the cable company hype. Satellite signals are very reliable, and cloud cover and planes flying overhead do not ruin the signal. Severe electrical storms may cause the occasional signal break, but it is usually temporary, and the inconvenience is not enough to persuade the average satellite user to switch back to cable. In our area we had a severe ice storm that knocked out the power for a time. Our satellite signal was out only because the power was out. As soon as the power came back on, we had satellite again. Cable users in our area, on the other hand, were out of a signal for weeks after the power returned because the cable lines were damaged by the ice storm.
- Can I get local stations? That all depends on what your provider can do in your area. It used to be that if you had satellite, you could not get local stations through your satellite provider. That is not often the case anymore, but it is still something you need to ask your local satellite provider. In some cases, getting your local stations may require two satellite antennas.
- Can I watch different channels on different TV’s with satellite? Yes. That’s the short answer. There are drawbacks, and this is where cable outstrips satellite hands down. With cable, you can have one receiver and hook up as many TVs as you want, and each TV can be tuned to a different channel. In the early days of satellite it used to be that every TV in the house got the same channel as the main TV did. With today’s dual tuner receivers, that is no longer the case. But here’s the catch: on dual tuner receivers each TV can be on its own channel, but dual tuner receivers can only handle two TVs at a time. If you want to set up more TVs, you’ll need more dual receivers, one for every two TVs.
- What kind of programming can I get? Providers such as DirecTV and Dish Network get content from the same turnaround channels as your local cable provider, so they can offer pretty much the same programming as cable TV does. Like cable, packages vary. It all depends on what you like and what you can afford. Stride for stride, satellite is typically cheaper than cable.
- What kind of offers are there? Like anything else, it all depends on where you look. Most satellite providers offer some sort of free installation and multi-room hookups. You just need to shop around.
It’s Your Decision
Whether you choose cable or satellite is ultimately your decision. They both have their pros and cons. But now that you have an understanding of how satellite TV works, you can make that decision based on real information, rather than hype.
Glenn Haertlein is teacher and freelance writer. To see his websites visit:
-or-
