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Wire oh wire

Like all powerline adaptors, the Netgear Nano gets warm in use, but not excessively so. They're cooler than my regular-size Devolo 200Mbps adaptors. The XAV5101 also consumes the oligatory half a Watt or less when it's not actively transmitting or receiving data.

My real-world testing of the XAV5101 involved pulling files down from a Nas box over the powerline link - the kind of thing most folk installing this kind of kit will do - and observing the measured throughput.

Netgear XAV5101 Powerline Nano 500

Doesn't run hot

Downloading from a WD MyBook Live network hard drive, connected by AFP, to my 15in MacBook Pro yielded a speed of 11.8MBps - 94.4Mbps. Of course this doesn't give the raw throughput - different data transfer protocols have higher or lower overheads; the same file copied over the same system but this time using SMB saw the time fall to 52Mbps, for instance. Moral: pick your protocols carefully.

The state of your home's wiring will have an effect too, so your mileage is going to vary. Here's how the new Netgear adaptors compare with the previous generation, to give you a guide to relative performance. Note that the Devolo product is a 200Mbps and so comes with a 10/100Mbps Ethernet port.

Netgear XAV5101 Powerline Nano 500

Download throughput in Megabits per Second (Mbps)
Longer lines are better

Using the iperf 2.0.5 bandwidth measure on the Vulture Central lab bench to fill the powerline pipe to capacity, I got a ten-run average one-way bandwidth of 182.1Mbps. These adaptors are clearly capable of getting much better performance than I got at home.

Netgear XAV5101 Powerline Nano 500

iperf average max bandwidth in Megabits per Second (Mbps)
Longer lines are better

Try as I might, I couldn't get the Netgear kit to interfere with either my DAB radio or the FM tranny I have in the kitchen. Well-behaving powerline adaptors are 'notched' to prevent them transmitting on used frequencies, and in all instances I've seen of powerline kit causing noise, the receivers have been placed near the adaptor.

Noisy adaptors there are, but I'm sceptical even these bad-behaved adaptors - notching does reduce performance - will be filling the ether with high-frequency noise will be sending police cars up the wrong street and causing aircraft to fall from the sky.

Verdict

Netgear's latest powerline adaptors deliver a decent performance, but it's their reduced size that's the real selling point here, ensuring they take up far less wall space than powerline Ethernet boxes of yore. They're clearly much faster than 200Mbps adaptors, though perhaps not sufficiently so to warrant replacing existing HomePlug AV kit. ®

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Netgear XAV5101

Netgear Powerline Nano 500 Ethernet-over-mains adaptor

Compact powerline adaptor with IEEE 1901 and HomePlug AV support.
Price: XAVB5101 two-adaptor starter pack: £100. RRP More Info: Netgear's Powerline Nano 500 page

Re: Interference

http://www.ban-plt.co.uk/ contains all of the reports Ofcom tried to bury, but were forced to release by the Information Commissioners Office. It begs the question: If PLT is such a benign issue, why are government organisations covering up reports they commissioned in to the effects on the radio spectrum? Why do Ofcom keep saying they can introduce a Statutory Instrument to effectively curtail interference from PLT, yet fail to do so?

The simple fact remains: These devices, and many Switch Mode Power Supplies, Panasonic Viera Plasma televisions and a host of other electronic crud, are flouting the EMC Directive in order to make a quick buck and the UK national regulator (Ofcom) and various government departments (BIS, DMCS) are complicit in allowing this to happen. If you continue to support PLT manufacturers, plasma TV manufacturers, and assorted crud mongers, you cannot complain when everything in your house fails to work due to unacceptable levels of EMC interference!

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Anonymous Coward

Re: When?

I've got the Cat5e cable Mage, will you talk to my landlord and come install the cable please?

What's that? The landlord didn't let you drill his 1860's house? Oh.

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4

The Tranny in the Kichen?

"Try as I might, I couldn't get the Netgear kit to interfere with either my DAB radio or the FM tranny I have in the kitchen."

Think yourself lucky the Gov snoop infrastructure isn't in place yet. You keep some poor gender-confused cow locked up in your kitchen, attempt to assault her with items of networking equipment and then write about it on a public web site?

You are bang-to-rights, sir!!!

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Re: Interference

Well actually these things definitely do bugger up spectrum used by licensed users, particularly that used by SW broadcasters where they are not notched.

As of October 2011 these devices newly placed on the market must meet EN55022B:2006, this is the standard which Comtrend and Devolo have been found to exceed by 40dB.

The reason Ofcom won't take action is because they are simultaneously responsible for both revenue generation from RF spectrum and for protecting it against interference. So they're desperately trying to wriggle out of any commitment to taking strong action as otherwise they may end up before the Euro-beak for affecting the free movement of goods within the EU.

If anyone discovers that new PLT devices are still radiating excessively, take action quickly, you have 6 months from the date they are placed on the market to complain *and* to get the complaint agreed.

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Re: Interference

Did similar tests a few years back when the standard was being worked out.

By using a radial spur, blocking filter and appropriately terminating* the mains wiring at both ends we managed to get a conducted emissions pass, and radiated didn't fail by much so could plausibly be sorted out.

However, the moment we used a ring final circuit (ring main) it failed quite spectacularly as this turns it into a loop antenna.

Notches work fine for avoiding radiated interference with specific other users, but you can't notch out everything so they will always squash somebody.

Put another way, it may be workable in much of mainland Europe because they mostly use radials, but it cannot work in the UK because we mostly use rings.

*Although the termination network drew more than half a Watt...

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