What is MPEG2 free to air all about? HOME
MPEG-2 FREE TO AIR; A BRIEF PRIMER
By Tom Taylor <tomt@Iglou.com> and
<http://mpeg2fta.com>
BEC, Coship,
Vistar, Zinwell, Pansat,
DMT, SA, ProSat, and the list goes on and on!
Where did all of these receivers come from? While the U.S. and
Canadian Cable industry distributes their programming largely via
products sold by Motorola and a few others, the rest
of the world chose the MPEG-2 format. Granted, even though, the
Motorola Digicipher II has some MPEG-2 attributes, it nevertheless remains a
totally proprietary platform. Who has chosen MPEG-2 as a platform?
Dish Network, Scientific Atlanta, and the rest of the world. Even
DirecTV is a early version of MPEG-2. MPEG-2 is a digital
platform that allows several digital broadcasts to be compressed onto
one frequency or channel. Without MPEG-2, Digicipher, or other
compression platform, it would not be possible to have direct
broadcast television services like DirecTV or Dish Network.
Equally important is the way the programmers get the their product to
their retail outlets such as DBS and cable. They too have chosen
compressed digital transmissions largely due to cost. PAX on GE-1 is an
example of this.
What does MPEG2-FTA mean? MPEG stands for Moving Picture Experts Group. It is a method for compressing data. FTA stands for "Free to Air"- meaning that the signal is not encrypted with conditional access. . Smart Cards or Conditional Access Modules, are generally used to decode scrambled signals.
MPEG-2 is not an encryption
method although encryption can be added. Dish Network uses the Nagra
system of encryption, DirecTV uses a News Data system, and full view big dish primarily uses the
Digicipher system. Transponder time has become so
expensive that with the exception of the preachers, the porno channels,
and the home shopping networks, it doesn't make sense to place only one
channel on one frequency. With HBO, and Discovery Networks
planning 25 channels each, it would take over two C-Band birds to air
their material the old fashioned analog way.
WHAT CAN BE SEEN ON MPEG2-FTA?
FTA or "Free To Air" simply means that the signal is not encrypted. Most cable type programming is encrypted. Occasionally programmers may turn the scrambler machine off and you can see a channel or two with an MPEG-2fta receiver. You will never see Time Warner cable programming, i.e. CNN, HBO in fta mode in the U.S.. CNN, and other international news channels, are available to viewers around the world in free to air mode, but not to the U.S..
In the U.S. there are a number of channels that are available via MPEG-2 FTA receivers that have indicated that they plan to remain in the clear or are believed to intending to stay clear. These include Saudi TV, Abu Dhabi, Thai TV, Kuwait TV, Syria TV, Taiwan, Iran, and as we go to press, Bloomberg TV all on Telstar 5, ku, which can be received on a .7 meter dish. The list changes now and then but these and more can be seen today.
GE-1 is the home of a bouquet of channels from Paxton Communication's PAX TV. PanAmSat 9 at 58 degrees west is home to the RTP, EWTN, CCTV China, NHK, Deutche Wella, an Arab bouquet in PAL, and a channel from Colombia. Some of the channels from the middle east have scrambled but their feeds to Australia remain in the clear. These feeds use the PAL format but a receiver like the BEC will convert the picture to NTSC, the North American format. MPEG2 FTA feeds are numerous and more and more are being added every day. The economics of compression, allowing more than one service on each frequency dictate that we will see more. Every time another satellite fails, and they are failing, we see the prices of transponder time go up. A couple of thousand dollars an hour for a better bird are not unusual for part time use.
WHERE DO YOU FIND LISTINGS OF WHAT IS AVAILABLE
The answer is simple, you find it on the Internet. There are two sites that are very good. Every day Christian Lyngemark spends a few hours updating information from every broadcast satellite in the world from his office in Sweden. His site is supported by advertisers. He relies on information from the programmers and satellite owners plus an army of volunteer spotters located around the world. His lists aren't always up to date or totally accurate, especially since many of the services go to great lengths to hide their feeds, but he is a very good detective. Christian's site is <http://www.lyngsat.com> lists everything from HBO to Solo Tango. A competing site is <http://www.satcodx.com> with similar lists.
WHAT IF YOU ARE NOT ON THE INTERNET?
Today, unless you live in an area with no phone access, there is no excuse for not being on the Internet. Even the DirecPC is available through DirecTV. Starband is available from Dish Network, and Pegasus Express is available from Pegasus that use satellite rather then phone or cable lines. Most people still use the slower dialup services because of their lower cost.
THE SECRETS OF PROGRAMMING AN MPEG-2 FTA RECEIVER
Most receivers come programmed with just a few channels or a couple of satellites. Since most receivers are made for the Asian markets it is not unusual to see satellites such as AsiaSat programmed into memory. Fortunately, all receivers come with the ability to delete programming. Taylor Enterprises is now able to program their receivers with most of the stations viewable in North America making them "plug and play". This is a special service they offer for their customers only.
With most MPEG2-FTA receivers, programming is done via the remote control. Fortunately, once the information is entered, the information is stored into the receivers memory.Originally the receivers required users to calculate L-band frequency, PID, FEC and to manually enter this information into the receiver. Today much of this is automatically calculated by most receivers. Most receivers require only two items be entered, the frequency, and the symbol rate.
For an example I am going to program a bouquet on T5-ku to illustrate how most MPEG-2 FTA receivers work. I have gone to <http://www.lyngsat.com> on the Internet. There I selected Telstar 5. I have scrolled to a group, we call them a bouquet, of SaudiTV, Palistinian, Dubai, Jordan, and other channels plus some radio stations. All of these channels are compressed onto one transponder. I know that I can receive this bouquet because column five indicates that the signal is MPEG-2 and no scrambling system is noted. No mention is made if Digicipher, Viaccess or IRDETO or other scrambling methods. PowerVu is a Scientific Atlanta system and can sometimes be received with MPEG-2 FTA receivers. At the bottom of the page I see that all MPEG-2 non scrambled listings are highlighted in a light yellow color. The last column tells the direction that the satellite sends the signal, i.e. Conus is Continental U.S., West is Western Hemisphere, East is Europe and so on. You usually wont see a "East" beam in the USA, although I have had some soccer fans claim they have seen some East beam transmissions with the right combination of antenna and beverage.
Typically most receivers program starting with the downlink frequency. Looking at the Lyngsat chart we see that is 11898 Mhz and this frequency is programmed into the first line in our example. This is simply the downlink frequency of the transponder . A few receivers like the Vistar require that the frequency be entered as 11898000. The next item that is typically required to be entered is the LNB L.O. freq. This is the local oscillator frequency of the LNB, which is located out at the antenna, that allows the received signal to be converted into a usable signal within the receiver. Domestic U.S. C-Band L.O. frequency is 5150 and Ku band is 10750. In our case T5 is ku so 10750 is entered. The latest receiver enter L.O. freq under a satellite setup and may note it elsewhere on the setup page. The receiver uses these two frequencies to calculate the L-band frequency that all receivers use to tune the channel. The next figure entered is the Symbol Rate. This is the rate the size of the digital package transmission, akin to a modem bit rate. This figure can be anywhere from less than 5000 to over 40,000. This figure is entered but be sure that you get the numbers in the right place. You may have to begin the entry with a 0 to make it work right, i.e. 6000 may have to be entered as 06000. In the case of our T5 example we can see from the forth column that the SR is 20000. The 3/4 is the FEC and is automatically calculated by most receivers. To see how a specific receiver is programmed, such as the BEC, take a look at my web page at <http://www.mpeg2fta.com>.
The PID rate, package identifier, and the FEC, Forward Error Correction, which corrects bit errors, are automatically calculated by most receivers. Some receivers also allow for manual PID entry allowing some signals with incomplete data stream information to be watched.
.
For further information on this
subject I highly recommend Rod Hewitt's " DVB North American MPEG-2
Information publication which can be found on the Internet at
<http://www.coolstf.com/mpeg>.
Also check our sister site at http://www.electronicsinventions.com
On
the BEC you press the menu key in the "transponder setup" mode
and follow the directions (Coship 2300, red button)
What are pids? Pids are package identifiers, every
digital signal requires them. Most programming allows the receiver
to set Pids automatically if they are not hidden in the data stream.
. Occasionally programmers will not send the
information to allow Pids to be set automatically. BEC and Coship
receivers allow for manual entry of PIDS. We were able to arrange with the manufacturer to add this feature,
unfortunately early users manuals didn't cover this feature.
WB feeds are an examples of channels that
our customers watch, that use manual pids. On the Coship,, manual
entry of pids is a bit more complicated. PIDs must be added to a
scanned bouquet, that is channel or group of channels. LET's say
you want to receive the WB feeds on Galaxy 11. If you try to
scan the WB bouquet, the Coship will tell you that there is a signal,
but it will NOT store any information,, so you must
"trick" the receiver. Go ahead and scan any other
bouquet, say the 3780 Ver. 30000 bouquet. Save it and
note the channels that are stored. Now under menu select
"Transponder settings". Now modify the bouquet, renaming
the channel, and changing the freq. to 3720, H, and s.r. to 26700.
Then from the channel settings menu setting, edit the channel and set
the pids. From Lyngsat.com you see that the VPID is 101, APID
(audio) is 102 ( not stereo). PCR pid is usually but not always
the same as VPID. 201/202 and 301/302 are additional
channels. Now save and test. Now you can go back and
eliminate all of the channels in the modified bouquet that you are not
using, the go back and reenter and scan the bouquet that you lost due to
modification. If you have one of the 9111e series Zinwell
receivers that we sold a few years ago you can enter manual PIDs.
IT must be a series 9111e to allow for manual pids. The 9111
series will not allow for manual entry of pids.