Just a simple question. What is it and what do we need to do?
I suspect most people in class will turn in a few paragraphs...
I turned it in to a four-page paper.
Here, for your viewing pleasure:
---------------------------------------------------------------------
The Impending Digital Transition of 2009
On February 17th, 2009, as the governments belated valentine gift to the nation, all stations must stop broadcasting analog TV signals and switch to digital broadcasts. A lot of people are asking themselves the question: ?What does it really mean for me??
Let?s take a look at how television is broadcast today over analog airwaves. In the world of analog today, a television station takes the signals required by television, which includes luminance, chrominance, synchronization and audio, and modulates it in to one signal (called a composite signal), which is then broadcast over radio waves across great distance. Because this signal is uncompressed, it utilizes a great deal of radio bandwidth.
Standard, non-digital Television?s are kind of dumb. All they can do is take the signal given to them and demodulate back in to separate signals. This not only takes up a lot of radio bandwidth, but is detrimental to the quality of the video and audio signal.
Now, enter digitally broadcast television. Instead of broadcasting uncompressed modulated signals over the air, television stations can now encode their broadcasts in a digital format for set top boxes or digital-ready TV?s to decode when it arrives. This allows for a higher quality stream to reach the end user without worry of degradation. For example, in analog television, if you did not receive a good signal from the broadcaster your picture or audio would be distorted. With digital, the data stream is either intact or it?s not. If you receive it intact, a 20% strength signal will display the exact same picture as a 100% strength signal. If there is ever a drop in the 20% signal where the data stream does not reach the decoder complete, the picture breaks and nothing is shown until an intact stream reaches the decoder.
What does this mean for bandwidth? It allows the FCC to redistribute the airwaves that old analog television was using up and freeing it for things like public and government use. A standard analog channel required 6mhz of airwave bandwidth to display a single channel. The same 6mhz can display two full-bandwidth (19.2Mbps) high definition channels or 5 standard analog channels in the same amount of bandwidth.
One of the most confusing things for people looking to the digital transition is confusing the terms DTV and HDTV. They sound very similar. While they do go hand-in-hand, they mean very different things. I think it will be easier to start with HDTV.
HDTV stands for High Definition Television. HDTV is simply the phrase used to describe picture that exceed the NTSC standard of 480 lines. HDTV can be 720 lines, the 720P standard; 540 lines, the 1080i standard; or 1080 lines, the 1080P standard. HDTV REQUIRES DTV, but it is not DTV.
DTV stands for Digital Television. It is used to describe the transmission of television signals via a compressed data stream instead of an uncompressed, modulated signal. These two should not be confused. When the digital transition happens in 2009, there will be plenty of stations broadcasting digitally, but not broadcasting HDTV content. DTV simply means that the broadcaster is using less bandwidth than previous analog content.
So, if you were confused about the differences between DTV and HDTV, hopefully that clears it up. At this point, you may be asking yourself: ?Self, how do I get this new compressed digital signal on my television that only supports analog signals??
It?s a good question and the answer is most likely a lot simpler than you think it is. The easy way is to get a television service provider like cable or satellite. Let me explain how each of these gets the signal to your old analog television.
For basic ?non-digital? cable, or analog cable, you don?t need to do anything but subscribe to your cable company?s most basic packages. These often provide local programming plus some extras and require no change in any way to most analog TV?s made after 1990.
I see the question forming right now. You?re asking yourself, ?Wait, I thought he said everyone had to move to digital. How would it be possible to remain with an analog signal??
The mandatory digital transition only applies to television signals broadcast over the air.
Remember how we talked about broadcast channels taking up 6mhz of radio bandwidth? Just imagine a coaxial cable from your cable company as virtual bandwidth. The same rules apply, except that the local cable company is controlling the frequencies inside the cable. They can do whatever they want with it. In order to deliver cable to your home, the cable company receives signals from various sources and modulates them so that your basic analog TV can demodulate them on your end. It?s like the cable company has it?s own virtual radio waves it can arrange however it wants.
Have you figured out how digital cable works then? If analog cable works essentially the same way analog television works then, you guessed it, digital cable works essentially the same way digital broadcasts work. The same signals are encoded on the cable companies end sent through the cable via virtual radio bandwidth, received by the cable companies set top box, which decodes the signal and then outputs a digital signal for digital TV?s or modulates the signal in to something standard analog TV?s can understand. The same benefits that digital broadcasts receive apply to digital cable as well. Each channel uses less bandwidth so that more channels can occupy the same amount of bandwidth.
Satellite works in much the same way, except it has been digitally transmitted for much longer. Basically, each satellite provider buys a slot in the atmosphere which they can then beam down a certain amount of bandwidth. The satellite beams down a digital encoded stream, which is received by the providers set top box (STB), decoded, and then output digitally for modern digital TV?s or modulated for older analog sets.
So, you?ve taken a look at satellite and cable and decided that you just can?t pay for TV but still want to watch all your shows. Well, the good news is, you don?t have to change out your antenna. There is no such thing as a ?HD Antenna?. All antennas pick up the same signals. The antenna you?ve had on your roof for 30 years won?t just magically ignore HD signals. The only thing to keep in mind are that some antennas are tuned to pick up one specific type of frequency, either VHF or UHF. In the past, most big name stations were broadcast on VHF radio frequencies and people frequently bought VHF-only antennas.
Most digital broadcasts, however, are broadcast on UHF frequencies. Now, if the signal is strong enough, even an antenna tuned to pick up only VHF will pick up UHF signals, but they may not be strong enough to deliver consistently complete digital data streams. The term we use n the internet is YMMV, or Your Mileage May Vary. It?s a very dependent situation that only you can figure out what is right for you. The best place to start would be AntennaWeb:
http://www.antennaweb.org
By putting in your address you can see where television station broadcast towers are in
your area and how far you are away from them, and what direction you may need to point your antenna to pick up the best reception. If you do wind up replacing your antenna, just keep in mind that you don?t need to buy one marked specifically ?HDTV/DTV Ready?. The OTA forums at AVSForum are full of people from all area who have experience setting up antennas and can make good suggestions for you:
http://www.avsforum.com/avs-vb/forumdisplay.php?f=45
As for displaying your OTA signals, you have two choices at this point. You can buy a digital ready TV. Now, this doesn?t mean you have to go drop a grand on a flat panel HDTV. Remember, HDTV and DTV are related, not the same thing. Store sell a wide variety of digital ready SD sets. I have a Philips 20? CRT television that I picked up at Best Buy on special for $140, very similar to this one:
http://www.bestbuy.com/site/ol...oduct&id=1165610667287
Even though it is a digital TV, it is not a HDTV but will continue to display digital signals received through an antenna. Of course, if you choose to buy a HDTV at this point to experience the benefits of a higher resolution picture (more vertical lines of detail), that?s cool too!
To keep your old analog set around for a little while longer, you will need a decoder/modulator for your television. A set top box that receives the encoded digital signal, decodes it, then modulates it in to a composite signal your television can understand. These are commonly called converter boxes. If you visit the following web site:
http://www.dtv2009.org
You can receive from the U.S. government, two $40 certificates towards a converter box of your choice, like this one, currently on sell at Best Buy:
http://www.bestbuy.com/site/ol...oduct&id=1213046767902
With this converter box and your $40 certificate, the total cost comes to $20. Even with something like this, you will still notice a significant picture quality improvement on standard definition programming and televisions, much like going from VHS to DVD.
I suspect most people in class will turn in a few paragraphs...
I turned it in to a four-page paper.
Here, for your viewing pleasure:
---------------------------------------------------------------------
The Impending Digital Transition of 2009
On February 17th, 2009, as the governments belated valentine gift to the nation, all stations must stop broadcasting analog TV signals and switch to digital broadcasts. A lot of people are asking themselves the question: ?What does it really mean for me??
Let?s take a look at how television is broadcast today over analog airwaves. In the world of analog today, a television station takes the signals required by television, which includes luminance, chrominance, synchronization and audio, and modulates it in to one signal (called a composite signal), which is then broadcast over radio waves across great distance. Because this signal is uncompressed, it utilizes a great deal of radio bandwidth.
Standard, non-digital Television?s are kind of dumb. All they can do is take the signal given to them and demodulate back in to separate signals. This not only takes up a lot of radio bandwidth, but is detrimental to the quality of the video and audio signal.
Now, enter digitally broadcast television. Instead of broadcasting uncompressed modulated signals over the air, television stations can now encode their broadcasts in a digital format for set top boxes or digital-ready TV?s to decode when it arrives. This allows for a higher quality stream to reach the end user without worry of degradation. For example, in analog television, if you did not receive a good signal from the broadcaster your picture or audio would be distorted. With digital, the data stream is either intact or it?s not. If you receive it intact, a 20% strength signal will display the exact same picture as a 100% strength signal. If there is ever a drop in the 20% signal where the data stream does not reach the decoder complete, the picture breaks and nothing is shown until an intact stream reaches the decoder.
What does this mean for bandwidth? It allows the FCC to redistribute the airwaves that old analog television was using up and freeing it for things like public and government use. A standard analog channel required 6mhz of airwave bandwidth to display a single channel. The same 6mhz can display two full-bandwidth (19.2Mbps) high definition channels or 5 standard analog channels in the same amount of bandwidth.
One of the most confusing things for people looking to the digital transition is confusing the terms DTV and HDTV. They sound very similar. While they do go hand-in-hand, they mean very different things. I think it will be easier to start with HDTV.
HDTV stands for High Definition Television. HDTV is simply the phrase used to describe picture that exceed the NTSC standard of 480 lines. HDTV can be 720 lines, the 720P standard; 540 lines, the 1080i standard; or 1080 lines, the 1080P standard. HDTV REQUIRES DTV, but it is not DTV.
DTV stands for Digital Television. It is used to describe the transmission of television signals via a compressed data stream instead of an uncompressed, modulated signal. These two should not be confused. When the digital transition happens in 2009, there will be plenty of stations broadcasting digitally, but not broadcasting HDTV content. DTV simply means that the broadcaster is using less bandwidth than previous analog content.
So, if you were confused about the differences between DTV and HDTV, hopefully that clears it up. At this point, you may be asking yourself: ?Self, how do I get this new compressed digital signal on my television that only supports analog signals??
It?s a good question and the answer is most likely a lot simpler than you think it is. The easy way is to get a television service provider like cable or satellite. Let me explain how each of these gets the signal to your old analog television.
For basic ?non-digital? cable, or analog cable, you don?t need to do anything but subscribe to your cable company?s most basic packages. These often provide local programming plus some extras and require no change in any way to most analog TV?s made after 1990.
I see the question forming right now. You?re asking yourself, ?Wait, I thought he said everyone had to move to digital. How would it be possible to remain with an analog signal??
The mandatory digital transition only applies to television signals broadcast over the air.
Remember how we talked about broadcast channels taking up 6mhz of radio bandwidth? Just imagine a coaxial cable from your cable company as virtual bandwidth. The same rules apply, except that the local cable company is controlling the frequencies inside the cable. They can do whatever they want with it. In order to deliver cable to your home, the cable company receives signals from various sources and modulates them so that your basic analog TV can demodulate them on your end. It?s like the cable company has it?s own virtual radio waves it can arrange however it wants.
Have you figured out how digital cable works then? If analog cable works essentially the same way analog television works then, you guessed it, digital cable works essentially the same way digital broadcasts work. The same signals are encoded on the cable companies end sent through the cable via virtual radio bandwidth, received by the cable companies set top box, which decodes the signal and then outputs a digital signal for digital TV?s or modulates the signal in to something standard analog TV?s can understand. The same benefits that digital broadcasts receive apply to digital cable as well. Each channel uses less bandwidth so that more channels can occupy the same amount of bandwidth.
Satellite works in much the same way, except it has been digitally transmitted for much longer. Basically, each satellite provider buys a slot in the atmosphere which they can then beam down a certain amount of bandwidth. The satellite beams down a digital encoded stream, which is received by the providers set top box (STB), decoded, and then output digitally for modern digital TV?s or modulated for older analog sets.
So, you?ve taken a look at satellite and cable and decided that you just can?t pay for TV but still want to watch all your shows. Well, the good news is, you don?t have to change out your antenna. There is no such thing as a ?HD Antenna?. All antennas pick up the same signals. The antenna you?ve had on your roof for 30 years won?t just magically ignore HD signals. The only thing to keep in mind are that some antennas are tuned to pick up one specific type of frequency, either VHF or UHF. In the past, most big name stations were broadcast on VHF radio frequencies and people frequently bought VHF-only antennas.
Most digital broadcasts, however, are broadcast on UHF frequencies. Now, if the signal is strong enough, even an antenna tuned to pick up only VHF will pick up UHF signals, but they may not be strong enough to deliver consistently complete digital data streams. The term we use n the internet is YMMV, or Your Mileage May Vary. It?s a very dependent situation that only you can figure out what is right for you. The best place to start would be AntennaWeb:
http://www.antennaweb.org
By putting in your address you can see where television station broadcast towers are in
your area and how far you are away from them, and what direction you may need to point your antenna to pick up the best reception. If you do wind up replacing your antenna, just keep in mind that you don?t need to buy one marked specifically ?HDTV/DTV Ready?. The OTA forums at AVSForum are full of people from all area who have experience setting up antennas and can make good suggestions for you:
http://www.avsforum.com/avs-vb/forumdisplay.php?f=45
As for displaying your OTA signals, you have two choices at this point. You can buy a digital ready TV. Now, this doesn?t mean you have to go drop a grand on a flat panel HDTV. Remember, HDTV and DTV are related, not the same thing. Store sell a wide variety of digital ready SD sets. I have a Philips 20? CRT television that I picked up at Best Buy on special for $140, very similar to this one:
http://www.bestbuy.com/site/ol...oduct&id=1165610667287
Even though it is a digital TV, it is not a HDTV but will continue to display digital signals received through an antenna. Of course, if you choose to buy a HDTV at this point to experience the benefits of a higher resolution picture (more vertical lines of detail), that?s cool too!
To keep your old analog set around for a little while longer, you will need a decoder/modulator for your television. A set top box that receives the encoded digital signal, decodes it, then modulates it in to a composite signal your television can understand. These are commonly called converter boxes. If you visit the following web site:
http://www.dtv2009.org
You can receive from the U.S. government, two $40 certificates towards a converter box of your choice, like this one, currently on sell at Best Buy:
http://www.bestbuy.com/site/ol...oduct&id=1213046767902
With this converter box and your $40 certificate, the total cost comes to $20. Even with something like this, you will still notice a significant picture quality improvement on standard definition programming and televisions, much like going from VHS to DVD.
