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Originally Posted by matt2056
Companies in the states have 10mb download stream. And yes we are trialing it... The network is capable of about 50mb down stream per customer.... All we need to do is open up more QAM's. The problem we have at the moment is we still provide Analogue to people... How sad!!!!!lol. Cuz we work though a RF network we get reflections of other frequence's up and down the bandwigth which provent us... this is all caused by analoque. Digital is better and cleaner on the network but we still need to work on it.. By the way each QAM is capable of 140mb downstream and take up 8mhz on a 1ghz local network which will feed about 350 homes. So the maths say ....... YES we can do it... I still don't know the upload though... Keep you posted
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Your entire HFC network is 350 home nodes with no combining?
Isn't the Telewest network DOCSIS 1.1 not EuroDOCSIS (so each MCNS broadband channel will use NTSC spec 6MHz not PAL spec 8MHz).
Don't uBRs / CMTSes emit their own QAM carriers (maximum usable bandwidth downstream on a single DOCSIS 1.0/1.1 downstream @ 256QAM approx 36Mbps) which are simply upconverted rather than needing a QAM unit to modulate them? To produce 140Mbps on an 8MHz channel you'd need 24 bits per symbol and kit to do that doesn't exist as the RF SNR requirement would be astronomical? Highest there is right now is the DOCSIS 2.0 standard 512QAM and 1024QAM, 9 and 10 bits per symbol respectively?
Aren't QAMs the modulators for VOD and other TV signals only, and the 140Mbps throughput is a reference to multiple RF channels being modulated simultaneously, or possible a reference to using statistical multiplexing and a reference to the amount of MP2 they are rated to mux and VBR control?
Apologies to those who didn't understand all of that
