AVS Forum banner
Status
Not open for further replies.
1 - 12 of 12 Posts

·
Registered
Joined
·
2,460 Posts
Discussion Starter · #1 ·
I know each transponder can hold a certain amount of shows and at this point its like 1 or 2 HD channels. If there become many Hd channels this will not be good. Do they have ways of increasing the amount each transponders can hold or how many transponders can be on a sattalite?
 

·
Premium Member
Joined
·
2,564 Posts
mpeg-4 would be the best hope.


------------------

Alex
 

·
Registered
Joined
·
973 Posts
They could change the FEC Foward error correction from 3/4 to 5/6 or 7/8. then they could do even more channels.

Of course then you would need a bigger size dish or a higher powered satellite in order to get a signal, especially during rain fade.
 

·
Premium Member
Joined
·
2,564 Posts
Meanwhile with 256-QAM cable company can squeeze almost 40Mbps net in a 6 MHZ slot? How much bandwidth does the average (upgraded) cable plant have? 500-750 Mhz? How does satellite compete with cable?


Little OT, but can you run 256-QAM on adjacent bands?


------------------

Alex
 

·
Registered
Joined
·
973 Posts
Did I say DirecTV. That's funny I don't recall it. Anyway Dish nework uses 20000 mbps 3/4 FEC and 24 mhz transponders. As I stated above if they lowered the FEC to 5/6 or 7/8 thus requiring either higher powered satellites or bigger dishes they could add more actual data and less FEC.
 

·
Registered
Joined
·
973 Posts
Quote:
Originally posted by work permit:
Meanwhile with 256-QAM cable company can squeeze almost 40Mbps net in a 6 MHZ slot? How much bandwidth does the average (upgraded) cable plant have? 500-750 Mhz? How does satellite compete with cable?


Little OT, but can you run 256-QAM on adjacent bands?

How does cable compete with satellite? It's true that 256-QAM cable doesn't need much bandwidth wasted for error correction unlike a system that must transmit RF over the airwaves. If a satellite has 32TPs each 24 mhz covering 2 polarities that would be 768 mhz of bandwidth. And remeber cable wastes most of their bandwidth doing analog very little of a 700 mhz plant is given to digital cable and internet.



[This message has been edited by satpro (edited 08-06-2001).]
 

·
Premium Member
Joined
·
2,564 Posts
Quote:
How does cable compete with satellite?
Should have reworded...how WILL satellite compete with cable (in the long run)


Satellite = 40Mbps/transponder x 32 transponders = 1280 Mbps


If cable were to eventually go fully digital

Cable = 40Mbps/6Mhz slot x 750 Mhz = 5000 Mbps


Once all subscribers in a given service are are using digital-ready boxes, how difficult would it be to switch analogue channels to digital?


I'm probably missing something.


------------------

Alex



[This message has been edited by work permit (edited 08-06-2001).]
 

·
Registered
Joined
·
4,038 Posts
36 Mhz transponder can carry data rate up to 80 Mbps.

Satellites usually have 24 to 32 transponders.
 

·
Registered
Joined
·
3,220 Posts
Dish has 3 spot beam satellites under construction. DirecTv has one or more under construction. However I believe they all will pimarily be used for adding more local channels. Beginning Jan 2002 the satellite providers are required to provide ALL local channels if they provide any.


Dish has said they will 'consider' putting HD on the 110/119 positions when they launch their new satellites. I believe the first is scheduled to launch near the end of this year.


Rick
 

·
Registered
Joined
·
632 Posts
There are also FSS frequencies very close to DBS. Ka has a lot more bandwidth, but is more prone to rain fade. Dish has a Ka bird on order - ostensibly for Data usage.


There is a lot of other bandwidth out there, but it is in use by somebody or somebody else wants to buy it.


For example the ground use 3G cell phones that everybody is trying to get working will conflict with DOD use (esp satellite control) and according to them could kill the GPS system. So again the US may not get the latest cell phones or use a 'non-standard' version.

 

·
Registered
Joined
·
973 Posts
yes cable could do major damage to satellite if they went totally digital. However, I don't think we will see that for at least another decade.
 

·
Registered
Joined
·
1,525 Posts
I merger between Dish and DTV would be a start. Are there any future plans for another satellite launch?




------------------

-Glenn


"Obstacles are what you see when you lose sight of your goals"
 
1 - 12 of 12 Posts
Status
Not open for further replies.
Top