Powerline networking, which uses ubiquitous home electrical wiring as a pipeline for data, has had a hard time winning popular support. Wireless networking has grabbed most of the public's mindshare, largely thanks to the Intel marketing machine. And the mains wiring technology has struggled with the industry's inability to …
What I really want to know is...
...if IEEE1901 "regulates" against the leakage which causes interference for Radio HAMs and apparently, if the new bands go ahead, various other radio spectrum users?
Assuming 1901 does, then, you have the problem of finding any decent tests, of if anybody makes a pair of PLT units, that actually abide by the spec (and the law).
I recently did my best to investigate this, and in the end bought a pair of Netgear AV500s, as they seem to be one of the few IEEE1901 approved devices currently on the market, but I've no idea if they are actually causing anyone any problems (as I would like to not, if I can help it!).
P.S. They were for the in-laws, and no, wireless or Cat5/6 are both not an option in this case! ;)
What is the fascination with this stuff?
"Powerline networking, which uses ubiquitous home electrical wiring as a pipeline for data, has had a hard time winning popular support."
So why does El Reg keep on about the bleedin stuff? We don't care, they are commodity items. It's only the Radio Hams that give a sh*t cos it screws with their play time!
I think wireless sold itself, at least to some extent.
If it's a choice between booting a laptop, for example, then just accessing the net from the bedroom/couch/toilet/shed/... and worrying about yet another plug in addition to the mains plug (if you even use one most of the time) then I think wireless is going to win.
Also, with WiFi in place you could use your WinMo device or smart phone through WiFi while at home to access your own network of get faster and (comparatively) free internet. Why would you also want to spend money on over-the-mains networking?
Of course if you have thick walls or just want to link, say, a TV to the internet and nothing else then mains is a great tech to have -- but wireless data technologies are far more versatile and impressive in most use cases. Heck, how many people want to plug their phone or laptop into a cable when they go to a coffee shop?
I have 2 media streamers in the house, neither of which have built in wireless (meaning extra adaptors) and I doubt I could stream 2 x 1080p movies at the same time, even over an 'N' WiFi network (not that I can at the moment, but the NAS is in the living room, so 1 streamer is connected directly). I have 4 of the Solwise AV200 units (1 byt the broadband router, 1 in the living room, 1 in the loft office and 1 in the bedroom) and they work excellently, IMO.
The problems with powerline networking...
If you don't count the cost of powerline networking equipment, the interoperability issue and the possibility of radiating interference from powerlines, powerline networking has other problems.
All of this is really too bad, as powerline networking seems like an idea that would have a lot of promise, especially in older structures. I do have some powerline equipment, purchased at severe discount. It's a neat idea when it works.
In the US and Canada at least, electricity is delivered to most homes over two 120 volt lines. In a well planned electrical system, the electrical fixtures should be evenly split across these two. This creates a problem when a powerline networking device needs to communicate to a device that is on the other "hot" line. The signal has to go back out of the building, through the pole transformer and come back to "jump the phases". Oftentimes, this is just too much to ask of the signal and it can't be done reliably or at all. This problem can be overcome, by installing a "phase bridge" or supposedly (NOT verified -- check it yourself before you even THINK of trying it!) by placing a suitable capacitor across the two hot lines at your incoming service panel.
What about the other problems?
Cost...it seems like this gear is almost universally more expensive than it "should" be. The prices have dropped so on wired and wireless gear alike. I suspect that limited production of powerline gear, due to its limited demand, keeps the price up.
Interoperability...I know there are supposed to be standards, but they don't seem to hold up well even when pieces of equipment say they're "compatible" with one another.
Radiating interference...this one I'm less clear about. The powerline Ethernet devices are far from the first to use the powerline as a transmission medium...countless "wireless" intercom systems, X-10 devices, telephone line "extension" kits and probably too many things to name have all done this. Where was the outcry then? (Yes, I realize that these devices might operate at differing frequencies to the powerline Ethernet stuff, but I'll bet there is some chance of radiation taking place there as well.)
Back when I wired my (very old) home for networking the first time, powerline gear didn't exist and Wi-Fi didn't either. Later, when I upgraded everything from coaxial Ethernet to Cat5 and fast Ethernet, Wi-Fi was just starting to become available and I did not consider powerline connectivity equipment as an option, if it even existed. During that process, I can promise you that I used all kinds of interesting words and struggled with a lot of situations.
If I had to do it again, given the issues with powerline networking, the lack of interoperability and the cost...I'd definitely use Ethernet or Wi-Fi.
"... by placing a suitable capacitor across the two hot lines at your incoming service panel."
I would suggest using two capacitors, in series, with six inches of physical separation between them, each being rated at 500V. The connection between them should be made with a low current fuse.
Belt, braces condom, rabbit's foot, etc...... nothing could go wrong :)
Regarding the radiating interference
X10 runs at 120kHz, low enough not to radiated well and in a band that is not widely used. The other uses are fairly intermittent use and aren't in 2-30MHz. Power-line networking, since it's using 2-30MHz, is using the shortwave band used by 1. amateur radio users 2. international broadcasters 3. ocean-crossing airplanes 4. ocean vessels and 5. a myriad of other users. 2-30MHz is radiated very effectively from house-sized wiring as it matches roughly the right antenna length. All the other users of this band have the allocation and authority to use it free of interference, and here's where PLC causes problems--it breaks this authority and allocation.
Hmm.. I was going to point out the PLC could have spent the time to get an allocation somewhere and then no one would complain about interference, but now I wonder if you could utilize the ISM bands for the PLC frequencies. No one would have an issue with that, except the cable loss would be rather high and I wonder if it would "interefere" (you technically can't interfere in an unallocated band) with wifi.
Re: Regarding the radiating interference
Said Ofcom in July 2010: There are now an estimated 1.8 million pairs of powerline adaptors in use in the UK. From July 2008 to the end of May 2010 a total of 214 cases of interference have been reported to Ofcom, all from shortwave listeners. 186 have been referred to BT to investigate - they related to its adaptors, which were faulty. 10 cases are unresolved.
That leaves 18 cases of clear interference from powerline adaptors: 0.001% of the total installed base.
Err, no !
>> a total of 214 cases of interference have been reported to Ofcom
Cases reported is not the same thing as actual interference. The actual cases of interference are almost certainly higher.
>> they related to its adaptors, which were faulty
More likely, they weren't faulty at all, just being used (as OfCom put it) incorrectly by being plugged in ! There seem to be plenty of stories of BT replacing them with a piece of cable etc. Saying they are faulty is an excellent way of deflecting criticism, and of course, proving otherwise is impossible when they've conveniently been disposed of.
>> That leaves 18 cases of clear interference from powerline adaptors: 0.001% of the total installed base.
No, it leaves 214 **reported** cases of clear interference, of which some were *claimed* to be because of faulty units.
Put simply, the current bunch are not fit for purpose, cause known interference problems, and it's not just radio amateurs who are worried about them. The CAA (Civil Aviation Authority) are worried about them - are you going to suggest that the CAA (who have a responsibility for safety in aviation) are just whining ?
OfCom know they cause problems, and they DO have the legal means of banning them - but as is normal for OfCom they won't do anything that might annoy big business. They're a watchdog - they watch but do b***er all else unless big business asks them to roll over and have their tummy tickled.
Agree with Unexpected Bill - why the high price?
Really I think the price is what puts most people off from using powerline networking. Why does it have to cost upwards of USD$90 retail to get a pair of these devices? WiFi wins by a huge margin on price alone, even disregarding the mobility/nomadicity it offers.
I currently use powerline networking at my house to connect my entertainment center equipment into the rest of my home network, where a WiFi link was flaky at best, and where it appears near impossible to pull cat5. It works spendidly, getting close to the rated 85 Mbps without any noticeable problems. I'd use more of it, and recommend much more of it as well, if the price was competitive.
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