PowerLine Networking Nearly Fails Our Tests

[loch-schwarz]

One aspect of broadband powerline communications is that the electrical wiring in virtually all cases is not designed to be a transport medium for frequencies in the HF spectrum and are not shielded. In other words a lot, if not most, of the HF energy fed into the lines are lost in the form of radiation: Powerlines act as antennas for HF.

This can cause serious interference to the reception of shortwave broadcasts as well as merchant shipping, marine weather, ship-to-shore stations, aviation weather, air-to-ground, etc. shortwave radio services and communication.

Personally, I feel it is highly irresponsible to use this technology.

For more information please visit:

 

[loch-schwarz]

The links dissappeared...

http/ftp.rta.nato.int/public/PubFullText/RTO/TR/RTO-TR-IST-050/$$TR-IST-050-ALL.pdf

http/www.bbc.co.uk/rd/pubs/index.shtml

http/www.arrl.org/tis/info/HTML/plc/

 

[bliq]

did I read that right- 802.11n has shorter range than 802.11g?

 

[PLC-LI]

Powerline communications may be finding a great friend in PLC-CLLI. Check it out in www.cal-lab.com or google search: PLC-CLLI to read more.

 

[Guest]

@ loch-schwarz:

That depends on the radiated power. Most likely not a big deal

 

[loch-schwarz]

@Anonymous23482fd: It depends on the total amount of radiated power, so in a large city, you need to take in into account how many tens of thousands of these things might be in use. Also it depends on how far you are from such a network. I live in an apartment in the centre of a large city, and when my neighbours started using a HomePlug system, they basically killed almost the entire shortwave for everybody in building.

 

[Guest]

I have used the DIR 655 for about 18 months. Origonally I used this for my computer network of 4 computers and my XBOX 360 and then I use it for streaming Netflix. It worked perfectly for everything except the XBOX and Netflix, which it would drop the signal approximately once every 3 hours. Not sure what the problem was. However, this did not happen with my omputers. I purchased the Net Gear 200 MB HD adapter to use on the XBOX and Netflix. The XBOX has never dropped the connection and speeds seem to be quite fast. Similarly, Netflix never drops the connection and the load times for streaming video is about twice as fast as the previous wireless setup. This is based on me watching the progress bar on the screen when a Netflix video is loading. My experience seems to be differnt than the test results in this article. I don't know why, but I am pretty happy with my setup. Perhaps one reason is I only have the XBOX/Netflix attached to the device. Everything else is still running wirelessly. One other thing, at least as far as I am concerned, it seems that if there is any bottle neck it is with my Internet connection. Its 8 megs download, which is significantly less than the minimum numbers in this article. I would love to hear the thoughts of others on this topic.

 

[dethsite2]

it's pointless comparing 2-4 different network mediums, for internet use and home network use..

powerline adapters are good for a n quick fix solution. though you must check if the power cable in your homes are compliant with it, failure to do this check will lead to the problems of data transmission.. as seen in this article when doing the test's..

nothing will beat Ethernet connection for networking, the biggest issue with power line tech is the topology effect you get akin to the old base 10-t network connection of the old days.

once you start more than 2 devices you decrease your overall transmit speed across the network not to mention the circuit breakers not to mention different fazes..

 

[dethsite2]

it's pointless comparing 2-4 different network mediums, for internet use and home network use..

powerline adapters are good for a n quick fix solution. though you must check if the power cable in your homes are compliant with it, failure to do this check will lead to the problems of data transmission.. as seen in this article when doing the test's..

nothing will beat Ethernet connection for networking, the biggest issue with power line tech is the topology effect you get akin to the old base 10-t network connection of the old days.

once you start more than 2 devices you decrease your overall transmit speed across the network not to mention the circuit breakers not to mention different fazes..

 

[dethsite2]

it's pointless comparing 2-4 different network mediums, for internet use and home network use..

powerline adapters are good for a n quick fix solution. though you must check if the power cable in your homes are compliant with it, failure to do this check will lead to the problems of data transmission.. as seen in this article when doing the test's..

nothing will beat Ethernet connection for networking, the biggest issue with power line tech is the topology effect you get akin to the old base 10-t network connection of the old days.

once you start more than 2 devices you decrease your overall transmit speed across the network not to mention the circuit breakers not to mention different fazes..

 

[dethsite2]

it's pointless comparing 2-4 different network mediums, for internet use and home network use..

powerline adapters are good for a n quick fix solution. though you must check if the power cable in your homes are compliant with it, failure to do this check will lead to the problems of data transmission.. as seen in this article when doing the test's..

nothing will beat Ethernet connection for networking, the biggest issue with power line tech is the topology effect you get akin to the old base 10-t network connection of the old days.

once you start more than 2 devices you decrease your overall transmit speed across the network not to mention the circuit breakers not to mention different fazes..

 

[chrisgeiser]

I'm Chris Geiser, the Product Line Manager for NETGEAR Powerline. We've noticed a few flaws in this test. I've discussed it with the author of the article -- Ed Tittel -- and he's reviewing the test results

1) The 802.11n speeds appear to be order of magnitude wrong -- perhaps stating MB/s when he meant to say Mbps. The PHY rate of 802.11n is 300Mbps MAX. Typically "real-world" performance would be 1/2 to 1/3 of the PHY rate. So, we would expect data rates to be on the order of 100-150Mbps in the best case -- not >300Mbps (and certainly not >700Mbps as was stated in one of the tests), which exceeds the data rates the PHY layer is capable of. Needless to say that we sell millions of wireless devices and have never seen wireless performance rates as high as those observed by Tom's Guide during their testing.

2) the D-Link product that was tested is UPA, not HomePlug AV. Typically the Aitana-based UPA product has a higher data rate, but lower "real-world" performance. This is a result of the poor noise performance of the DS2-based solution.

Ed has assured me that if the results are fundamentally flawed, they will be corrected and reposted.

 

[etittel]

Dear Readers:

Thanks to eagle-eyed Netgear Powerline AV product manager Chris Geiser (who posted just before me in the forums here at my request), we have discovered errors in the column of numbers for 802.11n on page 4 of the story (URL: http/www.tomsguide.com/us/Powerline-Networking-Test,review-1333-4.html)

Here’s a repeat of what IS there and what SHOULD BE (SB) there, in table form

Test 802.11n (IS) 802.11n (SB)
HD Video Playback 39.3 (314.4) 11.4 (85.2)
2x HD Playback 47.4 (379.2) 14.2 (113.6)
4x HD Playback 28.2 (225.6) 8.5 (68.0)
HD Video Record 48.4 (387.2) 14.5 (116.0)
HD Playback and Record 30.3 (242.4) 10.0 (80.0)
Content Creation 5.1 (40.8) 4.8 (38.4)
Office Productivity 19.3 (154.4) 11.2 (89.6)
File Copy to NAS 95.8 (766.4) 28.8 (230.4)
Dir Copy to NAS 5.7 (45.6) 3.4 (27.2)
Dir Copy from NAS 5.0 (40.0) 4.1 (32.8)
Photo Album 19.5 (156.0) 5.6 (44.8)

I have also asked the site editor, Rachel Rosmarin, to change the story to reflect these new numbers. You should see those changes in the next few days (I posted this on 7/14/09) as her insanely busy schedule permits.

There were two sources of error: I used a set of (abandoned) 100 Mbps FAST Ethernet numbers for the extremely high errors (HD playback, File Copy to NAS) by mistake (though I had wondered about the values that exceeded the theoretical maximum for the medium, Intel does say that some values can do this, and I didn’t inquire deeply enough to determine the error was mine, not theirs). I also made some mistakes transcribing results from the original NASPT screenshots. I apologize for my mistake, and will post this information to the forums as well.

 

[Guest]

There is a lot of metal in the walls of my relatively large house so Wireless N and Wireless G simply can't get through more than one or two walls. Powerline Ethernet is a lifesaver for me. The whole house is wired up and I get reliable connections throughout. Its not fast enough to stream HD video, but for surfing and backup, it works. Wireless N and G do not.

 

[Guest]

I have been using the netgear powerline with not problems. It is connected to my tv and we have been watching internet (youtube, netflix etc) with no problems, very quality picture... Perhaps because the wiring is faily new (4 years) it helps....

 

[JustWantToComment]

4 years + 6 months later, I came across the article, and I think it's a little unfair.

Like others have mentioned, they didn't test the devices across phases, or even mention anything about power phases. Also, just because the devices were tested in the same room doesn't mean the signal did not have to cross through the main panel! Sometimes, one or more of the receptacles in a room will be on a different circuit breaker than the other receptacles in the room! So, I consider their test procedure a little sloppy and thoughtless.

Also, I'm still happily running 10 Mbit/s ethernet. Anything that can transfer data faster than 1.25 MB/s is already overkill! Personally I'm looking for a WIRED solution, because Wi-Fi is just too unreliable, susceptible to external interference, and it causes interference to other devices too. I'd run some Cat5 wire, except I'm in an apartment and that violates the tenant contract. So.... HomePlug Powerline AV addresses my specific problem, and if it works, it's precisely what I need and what I want.

Also, these units are now selling for $25 - $45 for a PAIR. That's more than reasonable.

Trying to convince everyone to go Wi-Fi is just being ignorant to some people's specific needs.