How many channels can NTL put on their cable ?

CO19

Just wondering what's the max number of channels NTL can send through the cable ?

yayamark

at the moment 126 on chorus!

Ask no questions ull be told no lies:cool:

CO19

hmmmmmm....I know NTL have about 170+ channels including radio stations coming through their cable now but I meant what's the limit they can fit into the cable eg 200 odd 300 odd channels ?

watty

Twice as many if they use MPEG4. But half as many if they want to sell more Broadband, so in the long term maybe closer to 150 to 200 than 400, but using MPEG4 to allow more space for broadband and IPTV.

conax

I would think that NTL don’t even know this, as it would depend on too many factors. In the perfect world it should be possible for them to hit the 1000+ channel mark, but that would depend on the compression used, the number of subscribers off each node (some are higher than others) the stability of Line amplifiers the ability of the Set top Box to handle resolve multiple carriers. The bandwidth from the optical node to the ring and useable bandwidth on the ring back to the headend, their ability to manage an maintain a loaded network and so on.

watty

1000+ is impossible on realistic cable trunks unless there is fibre to your front gate.

That number of channels is limited to about 25m and would assume no broadband.

Probably most "Real" channels can be accommodated in 100 and niche in a 2nd 100. Marketing & profit wise, there is no advantage going much past the 200, the rest of the bandwidth is better making money for phone calls and Broadband.

conax

yep, except the question was what would be the limit with no mention of broadband, and the Theoretical answer was (in the perfect world) furthermore the capacity of the 540 trunks would carry the 1000 channel mark and as for the 25 meters you are assuming top end as opposed to compression.

CO19

Thanks lads for the replies.

maxg

A rough calculation.
Available frequency range 100 mhz to 850 mhz give 750.
750 divided through 8 mhz bandwidth give 93 transponders.
Rounded off to 90 and multiplied with 8 digital tv channels in good quality per transponder give 720 mpeg2 channels.
90 multiplied with 10 tv channels in medium quality give 900 mpeg2 channels.
Qam256 would give an extra 30% capacity boost.
Analogue channels, broadband downstream and phone occupy capacity and lower the number. In cable network parts with old equipment the full range is not usable.