Tp space utilization

[Ankit Jain]

As we all know videocon has 54mhz transponders and tatasky has 36 mhz. There is also migration going on in ts and now they have the capacity to have 35-36sd channels in mpeg4 quality in each tp. If we go by this way then d2h must have a capacity to have more than 50sd channels in each tp. But they are max 47 channels. Why are they not adding channels in the. rest space left???


Mods plz throw light on it.

 

[SivaG]

becoz of FEC variation. fec bits takes more bandwidth. tatasky uses 5/6 fec and its channel bandwidth 75 mbps(75+15fec=90). d2h uses 2/3 fec its channel bandwidth 88 mbps(88+44fec=132) even at 54 mhz.

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channel calculation: just for ex:
tata 40ch*1.8=72 mbps
d2h 48ch*1.8=86 mbps

 

[Rushil]

airtel have which bandwidth

 

[SivaG]

airtel use 3/4 fec 66mbps(66+24fec=90) at 36 mhz

 

[Rushil]

how you can calculate?and some tata sky transponder frequency is 7/8 also

 

[people]

3/4 and 5/6 are high frequency,that is the reason airtel and tatasky in good quality.

 

[SivaG]

rushil.D bro. its dvbs2 TP only.

 

[people]

Videocon D2H 2/3 with 87 not giving got quality,but their 3/4 with 78 will give good quality.
Tatasky 5/6 with 74
Airtel 3/4 with 66

Kem Siva could you give Raliance ,sundirect and dish tv FEC and bit rate.

 

[SivaG]

fec-forward error correction bits. 5/6 fec means for every 5 data bit 1 redundancy bit wil be added for error correction which ensures errorless data transfer.

5/6 fec
5-data bit
6-total bit(5data+1 fec)

fec decreases the useful bandwidth. if we use 1/2 fec it will reduce the useful tp capacity to half. but if we use lower order fec data become noisy. so should keep balance b/w two. i think picture quality not come from fec. fec related to signal quality.

3/4 fec is better than 5/6 fec. if rf signal is good no matter what it may be.

 

[Ankit Jain]

Bro its something else I guess as no company is fool.Why would they waste crores of rs. on buying a new tp when they can just change the fec.