Snow & Speed Increase!?

Hello All,
I have been on the Be Unlimited network for over a month now and have been happy with everything concerning Be, although a little more speed is always welcome!

Imagine my surprise this morning, not just at the amount of snow that had fallen but the Belkin F5D9630-4 router which would never sync higher than 6722kbps was doing so at 7117kbps! A couple of recycles later and the router had a sync level of 7201kbps. In the past month the sync rate has been steady during the day between 6650 - 6722kbps and between 5700 - 6000kbps after sunset. As of 1100 a resync by the router itself brought the sync rate down to around 6850kbps and since then sync rates have been slightly lower than they were prior to this morning and the weather changed about that time too. No other meteorological events seem to have affected the line in the last month.

The setup includes 2 extensions as well as the master with ADSL Nation filters on all sockets with readings that are generally the same across all sockets, but the router lives on the daisy-chained 2nd extension. The data stream is interleaved and the residence is 2.857km from the exchange, so say Be. Here are the stats from this morning with 'normal' ones in brackets.

Data rate 7201 1200 (6717 1023)
Noise Margin 6.1 5.8 (6.3 8.1)
Output power 20.1 12.4 (19.6 12.4)
Attenuation 50.5 28.0 (46.0 27.8)

Any ideas concerning what happened?

Thanks,

Can snow block RF intereference?
Heavy rain can intefere with radio and block out sky TV.Maybe snow can block RF from the phone lines.

Don't know about blocking it, but it's possible that low temperatures can reduce the noise generation within cables. I've seen debate on this effect in other years, and I don't think a firm conclusion was ever arrived at.

but it's possible that low temperatures can reduce the noise generation within cables.

Maybe the copper has contracted (due to the low temperatures) and the OP's line is a bit shorter than it used to be

I think that was suggested last time, along with ideas about superconductivity, etc. I'm not sure that a change of 15 degrees or so would make a big difference ?

In reply to:

---

it's possible that low temperatures can reduce the noise generation within cables.

---

Low temperature will have this effect, but will probably be drowned out against the background of crosstalk and general ambient noise from other electrical sources. The low temperature is reducing the resistance of the copper cores and reducing attenuation. This in turn allows the line to attain a slightly higher speed.

Nice theory, but shouldn't my routers be reporting a lower line attenuation ? Neither are, but since the snow my sync rate has gone up a little.

I seen that a few years back on another line i was connected to. Never did figure out if it was the snow or not but it was gone when the good weather came back some time around july

In reply to:

---

Nice theory, but shouldn't my routers be reporting a lower line attenuation ?

---

Not necessarily, because the change may not quite register on a decibel scale, although for a 10degC difference, the effect on resistance is significant [see here]. However, it would tend to bring some marginal fail frequency bins into use, possibly with a disproportionate effect on speed.

snow = cold = contraction = shorter line length

Copper resistance drops by 0.4% with every degree C, however hasn't the early morning temperature risen by 5 degrees since the cloud cover arrived? We've been seeing -5C in Herts most nights for the previous week, but only just freezing yesterday and today.

My guess is that the 2-3inch blanket of snow on the ground helps with shielding RF interference from underground cables.

The reduction in road traffic might also have helped. I saw a very significant line sync increase (an extra 1Mbps) over the Xmas holidays, so perhaps there is a net reduction in RF background noise when people aren't at work.

I think that's more likely. At the depth of most BT ducts, you're not likely to see much of a temperature change anyway.