Silicon to stop next-gen powerline standards war
Will the mains networking biz put its squabbles behind it?
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 rally behind a single standard during its evolution through 14Mb/s, 85Mb/s and 200Mb/s incarnations.
Faster speeds are coming, but powerline proponents are still worried that the existence of two, new competing standards for the next generation of Ethernet-over-mains technology will see a continuation of the current standards war.
The two rivals are the IEEE's 1901 and the ITU's G.hn. Both are designed to more than double the performance of today's 200Mb/s powerline links, the better to allow punters to send multiple 1080p HD video streams around the home simultaneously. Get that right and almost any other kind of data consumers want to transmit will easily fit into the available bandwidth.
Both have powerful backers. The HomePlug Alliance, overseer of the HomePlug AV 200Mb/s standard, has given its thumbs up to 1901, not least because 1901 is compatible with its own technology.
The IEEE standard also incorporates HD-PLC, a powerline technology developed in Japan but which is very similar to HomePlug AV. HD-PLC uses wavelet compression; HomePlug uses Fast Fourier Transform to do the same job. In other respects, the two specifications are effectively the same. For that reason, 1901 combines the two.
HD-PLC is relatively unknown in the West - though it's big in Switzerland, says Dr Stephan Horvath, CEO of local technology company Advanced Communication Networks - where HomePlug AV has become the de facto standard after beating a rival offering from the Universal Powerline Association.
The UPA effectively collapsed last year when its main backer, Spanish chip company DS2 shut it doors. Before its demise, DS2 had been looking to G.hn as the next step in powerline networking.
It wasn't the only one. The world's biggest chip maker, Intel, has lent its support to the standard, which is being promoted by the HomeGrid Forum. The Forum is backed by a fair few service providers, including BT.
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.
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.
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.
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.