Bandwidth of satellite transponders

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bite

Superkomanda
Messages
237
My Satellite Setup
0.8W; 4.8E; 13E (90cm),
19.2E; 28.2E; 36E (110cm),
DM800SE, DM600
My Location
Riga, Latvia
Hello there! :)
So I was talking with the friend today and he asked me, what's the bandwidth of transponders (I mean in "mbps")? And, I couldn't answer properly, so I would like to know.
As I know, there are 24 mbps on DVB-S. And there's no difference, if signal is in MPEG2 or MPEG4, bandwidth will be the same on transponder?
The next thing is DVB-S2. What's the bandwidth there? Thanks again! :)
 
bite

bite

Superkomanda
Messages
237
My Satellite Setup
0.8W; 4.8E; 13E (90cm),
19.2E; 28.2E; 36E (110cm),
DM800SE, DM600
My Location
Riga, Latvia
Hello there! :)
So I was talking with the friend today and he asked me, what's the bandwidth of transponders (I mean in "mbps")? And, I couldn't answer properly, so I would like to know.
As I know, there are 24 mbps on DVB-S. And there's no difference, if signal is in MPEG2 or MPEG4, bandwidth will be the same on transponder?
The next thing is DVB-S2. What's the bandwidth there? Thanks again! :)
 
BombedOne

BombedOne

Regular Member
Messages
1,107
My Satellite Setup
Covering 30W-105.5E range, two motors, C and Ku band. Various receivers/cards/cams/etc.
My Location
Republic of Georgia
Rougly bandwidth equals SR-FEC. Say SR is 20000 and FEC is 1/2. Then bandwidth will be 20000-20000/2=10000.
 
BombedOne

BombedOne

Regular Member
Messages
1,107
My Satellite Setup
Covering 30W-105.5E range, two motors, C and Ku band. Various receivers/cards/cams/etc.
My Location
Republic of Georgia
Rougly bandwidth equals SR-FEC. Say SR is 20000 and FEC is 1/2. Then bandwidth will be 20000-20000/2=10000.
 
T

Tsiklon

Regular Member
Messages
88
My Satellite Setup
Various
My Location
Europe
The transponder will always have the same bandwith in terms of MHz. The data capacity (Mbps) will then be determined based on the modulation (DVB-S vs DVB-S2) and the error correction (FEC) employed. A higher power TP will require less error correction. A channel compressed in MPEG4 will require a lower data rate than one compressed in MPEG2.

The picture has a nice comparison for 36MHz TP.
 

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Tsiklon

Regular Member
Messages
88
My Satellite Setup
Various
My Location
Europe
The transponder will always have the same bandwith in terms of MHz. The data capacity (Mbps) will then be determined based on the modulation (DVB-S vs DVB-S2) and the error correction (FEC) employed. A higher power TP will require less error correction. A channel compressed in MPEG4 will require a lower data rate than one compressed in MPEG2.

The picture has a nice comparison for 36MHz TP.
 
B

Bobben_no

Member
Messages
2
My Satellite Setup
Topfield 7700 HDPVR,Fibo120cm and a lot of other receivers and antennas.
My Location
Norway
The capacity of a transponder can be calculated here if symbolrate, FEC etc. is known:
_http://www.satellite-calculations.com/Satellite/bitrates.htm

Some of the 33MHz DVB-S2 transponders on 1-west Thor5 T2 is currently transmitting at 66.8Mbits which gives room for 4 H.264 HDTV channels.
DVB-S2 for direct to home broadcasting should be able to deliver up to 80Mbit/s in 33MHz but it requires more EIRP than most satellites can provide (or a big receiving antenna).

A typical transponder for MPEG2 SD channels delivers around 38Mbit/s.
Symbolrate=27.500 FEC=3/4 gives 38Mbit/s in DVB-S.
Symbolrate=28.000 FEC=7/8 gives 45Mbit/s in DVB-S.
 
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Bobben_no

Member
Messages
2
My Satellite Setup
Topfield 7700 HDPVR,Fibo120cm and a lot of other receivers and antennas.
My Location
Norway
The capacity of a transponder can be calculated here if symbolrate, FEC etc. is known:
_http://www.satellite-calculations.com/Satellite/bitrates.htm

Some of the 33MHz DVB-S2 transponders on 1-west Thor5 T2 is currently transmitting at 66.8Mbits which gives room for 4 H.264 HDTV channels.
DVB-S2 for direct to home broadcasting should be able to deliver up to 80Mbit/s in 33MHz but it requires more EIRP than most satellites can provide (or a big receiving antenna).

A typical transponder for MPEG2 SD channels delivers around 38Mbit/s.
Symbolrate=27.500 FEC=3/4 gives 38Mbit/s in DVB-S.
Symbolrate=28.000 FEC=7/8 gives 45Mbit/s in DVB-S.
 
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