Well, if they're insulated they won't reach the lower limit as they generate heat.

I was just about to say the same thing; when I had homeplugs / powerline devices / whatever you wish to call them, they were always quite warm. So I'd suspect that in a cold garage they'd still be fine.

..besides, my mobile is only rated down to 0c, but this winter just gone I left it in the car overnight; -15c that night and it worked fine. Using something outside its rated comfort zone, while not great, won't cause the device to skim off the face of the planet and vanish.

"many other users of the spectrum ... don't have the benefit of notch filtering. "

Such as, er, DSL. Whether it be ADSL, VDSL, or whatever, it's medium wave and short wave radio, except that the signals come down the phone wires rather than through the ether.

Anything that can and does interfere with medium wave and short wave radio can and at times will interfere with DSL broadband.

It's hard enough getting and keeping high speed DSL working as things are today without the prospect of having the RF spectrum increasingly polluted by powerline broadband kit too.

Trying to diagnose a DSL fault in the presence of interference from a powerline broadband transmitter somewhere between end customer and exchange/DSLAM/etc won't be fun.

In fact before too long if enough BPL/PLT kit gets out there, it's probably going to render xDSL undiagnosable in the case of a fault, and hence commercially unusable in the mass market.

This will be not just because of powerline ethernet kit, but because every consumer electronics manufacturer who sees BPL/PLT kit being allowed to radiate like crazy with no penalty will want to save a dollar or two per unit by no longer including the RF suppression components which have previously been considered essential.

But that's OK, because PLT helps sell BT Vision and the like, and we'll all have interference-free fibre to the premises in five years or so won't we. And in areas with a high density of PLT, we'll need something other than DSL. Shame about the non-FTTP areas where cable broadband isn't available either, but hey, it's a basic human right to pollute the RF spectrum so you can watch movies/football without paying Sky, innit.

I have not seen a homeplug yet that enables you to watch Sky TV for free. In fact they are far less efficient than running an Ethernet cable. They slow what is trundling down the copper already.
What is far more worrying, is the high power ISP PLT trials along street three phase mains cables, high up and unshielded and radiating left right and centre. You then get into recorded interference to aircraft communications, which still run HF on long haul flights. Homeplugs are a far more local problem as far as interference, though you could have a neighbour hook into your broadband if he is on the same phase.

Well over a million HomePlug devices in use in the UK so should have wiped out the amatuer radio, crashed a few planes and reduced ADSL to zero throughput by now

In reply to a post by MrSaffron:

Well over a million HomePlug devices in use in the UK so should have wiped out the amatuer radio, crashed a few planes and reduced ADSL to zero throughput by now

A check through the thread will show that homeplugs are notched at amateur frequencies, along with the recorded interference to the likes of aircraft relating to high powered ISP trials along street three phase � I realise getting the last word is paramount here, but it is best to wake up first!

How many airplanes have crashed in the UK as a result of these million HomePlug devices?

As for BPL for public ISP stuff, not aware of any live deployments, there was trials, but died a death not because of interference but costs and fixed lines exceeding by many times the speed capabilities

These devices, despite operating at HF, are quite happy to wipe out your neighbours Band 2 FM and DAB at VHF!. These are protected frequencies and you are liable legally for any interference caused.
https://www.youtube.com/watch?v=_wvtBhilvz4
An example of even the notched amateur frequencies being well out of spec.
https://www.youtube.com/watch?v=6teyGvdrs5Y&feature=...
Just imagine if PLT is ever let loose at high power street level by some 'Honest' ISP!

I take it the answer is zero.