In reply to a post by kwikbreaks:

Not relevant now after your answer to my question but by USB I meant upper sideband. Amplitude modulation of an RF signal results in two sidebands either side of the nominal channel frequency. Only one of the sidebands is needed to demodulate the signal and the old analogue TV used what is called vestigal sideband with the upper sideband used and the lower sideband mostly removed.

Not sure where I got 60MHz from but obviously it was wrong anyhow.

Ahh ok. The 6.4MHz width of the carrier includes side bands. They can be placed exactly 6.4MHz apart without issue if an operator so desires.

EDIT: Sorry I should be more accurate. A root raised cosine filter is used to eliminate the side bands. This leaves a symbol rate of 5.12MSym/s despite the bandwidth being 6.4MHz.

So the 6.4MHz doesn't actually include side bands, it includes overhead from removing them via matched filtering.

Edited by deleted (Wed 25-Sep-13 18:48:26)

DSP chips have completely changed the way all these things are done and I make no pretence of understanding them. The amount of data that can be crammed into limited bandwidth these days is quite staggering.

I agree. Some incredibly clever people working on this stuff. It's way beyond me.

In reply to a post by KRS:

Have the same package and I have the same problem. Complete nightmare. Support is unresponsive and incompetent. I am looking for a new provider as VM i really not up to the job.

Yes exactly my sentiments. They USED to be good and much better than BT, but in past 4 months there connections have become totally unreliable with drops every hour at least .Engineers say it is happening to hundreds they know of if not more.All because the Management wont listen to the engineers and fix the servers.

In reply to a post by ilikesurfing:

Yes exactly my sentiments. They USED to be good and much better than BT, but in past 4 months there connections have become totally unreliable with drops every hour at least .Engineers say it is happening to hundreds they know of if not more.All because the Management wont listen to the engineers and fix the servers.

If the management wont listen to the engineers and the customers end, then surely the customers had every rights to cancel the service!