[LINK] RFI: ADLS2+ Performance

[Craig Sanders]

On Thu, Jul 05, 2012 at 08:42:54PM +1000, TKoltai wrote:
> If in June 2011 they had 640,000 DSL customers and in July they had only
> 500K ports, that's a very respectable 20% floating customer base.
> 
> In other words, a most reasonable Signal to Noise ratio.

until i read this, i thought that you're a kook but you do have a good
knowledge of the ISP industry and a reasonable grasp of the technology
behind it.

but what you're saying there makes no sense. what you claim is SNR
is actually customer (or device) contention, the number of consumers
competing for a given limited resource. in this case, users:ports -
640K:500K isn't bad at all, many/most users don't leave their computers
connected all the time even with "always on" ADSL.

it is not, however, anything like or at all related to signal-to-noise
ratio.

SNR refers to the strength of the SIGNAL (the useful information being
transmitted as seen by the receiver) versus the level of background
noise. i.e. it's a measure of the overall quality of the connection path
- whether that's wires or wireless.

To greatly simplify: a high SNR is "good". low SNR is "bad". too much
noise can reduce (or completely overwhelm) the information carrying
capacity of the channel.

http://en.wikipedia.org/wiki/Signal-to-noise_ratio


craig

-- 
craig sanders <cas at taz.net.au>

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