G.hn Silicon Emerges from Vaporware Territory
by Ganesh T S on February 2, 2011 3:33 PM EST- Posted in
- Powerline Adapters
- G.hn
- HomePlug
Unlike Sigma Designs, Atheros had no new silicon to show off at CES 2011. Instead, the focus was on increasing reliability and creating a better experience for consumers by making their current products run with better performance under adverse conditions.
Atheros termed this as 'Smart Link' technology. They indicated that this technology would roll out to all powerline adapters with 3 prongs. In simple terms, the current powerline adapters which are two pronged utilize the phase and the neutral wires for communication. The phase wire is affected by noise to a large extent. In case the ground wire is present, its usage over the phase wire can result in improved performance. Most surge protectors avoid any sort of filtering on the ground wire also. Smart Link technology determines dynamically whether the phase wire is affected with too much noise and decides to route through the ground wire.
Our biggest issue with Smart Link is that it will become available only on powerline adapters with three prongs. All the 500 Mbps offerings from Netgear and D-Link introduced at CES are two pronged versions. It appears that end users (who are purchasing the 500 Mbps powerline adapters in the North American market in the near future) will not be able to take advantage of 'Smart Link' even though it is only a firmware update.
When asked about next generation silicon in the powerline space, we were told that nothing new would be unveiled till the HomePlug AV2 standard gets ratified. In the meanwhile, Atheros is also working on their hybrid home network platforms (Hy-Fi) and the IEEE P1905 standard. While Atheros concentrates on HomePlug AV2 and IEEE P1905, it is the ideal time for G.hn silicon vendors to catch up.
Atheros Hy-Fi for Hybrid Home Networks
The slow rollout of the AR7400 based 500 Mbps powerline adapters in the North American market is also puzzling. As Brian Dipert of EDN notes, the firmware in the North American versions don't seem to be optimized for performance yet. It remains to be seen as to how Atheros and its customers handle this issue.
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wolrah - Thursday, February 3, 2011 - link
Sorry bud, but you're completely wrong. Look up the G.hn specs yourself. Depending on the region, on power lines it'll use anywhere from 1-200MHz. The power lines in your house are in general unshielded, making them effectively an enormous (though not particularly well optimized of course) antenna. The frequencies in use overlap with numerous radio bands, including a number of amateur bands, CB, commercial AM/FM, and commercial/government SW/MW/LW. I don't believe most public safety spectrum at least here in the US is that low down, but there probably is some. Particularly in amateur HF and SW/MW/LW being able to receive weak distant signals is important, so any interference on those bands is an annoyance to area users.I'm not sure why you bring up cordless phones. BPL and power-line networking don't come anywhere close to those, so there's no reason to think it passing the "teenage girl test" means anything at all (900MHz, 1.8GHz, 2.4GHz, and 5.8GHz are the four cordless phone frequencies seen in the US).
Again it will not interfere with any unlicensed radio services I'm aware of other than CB, but you're putting a fat signal in to a huge antenna right in the middle of a lot of licensed spectrum. The area of effect isn't huge, but as an amateur operator if you were my neighbor and you were broadcasting anything on the HF bands I'd offer to help fix it if possible, but if it couldn't be told to not operate in certain ranges it's turning off or you're getting an FCC complaint for broadcasting without a license and interfering with licensed users.
derkurt - Sunday, February 6, 2011 - link
I don't know exactly about the new G.hn devices, but a HomePlug AV2 500 Mbit/s device uses a spectrum from 2-68 Mhz. The standard employs these frequency filters (source: German wikipedia):* f ≤ 1,71 – AM Broadcast and below
* 1,71 < f < 1,8 – between AM and 160 meters band
* 1,8 ≤ f ≤ 2,0 – 160 meters amateur band
* 3,5 ≤ f ≤ 4,0 – 80 meters amateur band
* 5,33 ≤ f ≤ 5,407 – 5 MHz amateur band
* 7,0 ≤ f ≤ 7,3 – 40 meters amateur band
* 10,10 ≤ f ≤ 10,15 – 30 meters amateur band
* 14,0 ≤ f ≤ 14,35 – 20 meter amateur band
* 18,068 ≤ f ≤ 18,168 – 17 meter amateur band
* 21,0 ≤ f ≤ 21,45 – 15 meter amateur band
* 24,89 ≤ f ≤ 24,99 – 12 meter amateur band
* f >= 28,0 – 10 meter amateur band
In Germany, you are allowed to use Powerline devices as long as they don't interfere with other HF applications in your neighborhood. If they do, the Bundesnetzagentur (German FCC) can be called, which may request removal of the source of interference.
So far, I haven't heard of a single case where a radio amateur successfully requested removal of a HomePlug device. Keep in mind that the amateurs are likely to be the only ones which might be disturbed by PLC at 2-68 Mhz. In fact, as far as I know, the filters mentioned above cover all frequencies where a radio amateur is legally allowed to operate within the 2-68 Mhz range. Also, although PLC is admittedly turning the power wiring into an antenna, the signal strength remains small compared to other in-house HF applications, such as Wi-Fi.
In theory, PLC is a "dirty" solution and looks like it would be bound to cause problems. In reality, devices such as mobile phones, babyphones (which also use the power lines), and even WLAN are far more likely to annoy your neighbor.
davmat787 - Sunday, February 6, 2011 - link
Excellent post sir. Just the kind of complete and detailed post one would expect from a German. :)HoosierEngineer5 - Thursday, February 3, 2011 - link
Do any of these technologies replace the X-10 modules, or are they simply replicate Ethernet? It would be great if these could actually DO something other than pass data...andrewmc - Thursday, February 3, 2011 - link
Very nice. So when do I get my Homeplug Green PHY silicon.aahjnnot - Friday, February 4, 2011 - link
Powerline networking is relatively successful in Europe and Asia compared with North America because our housing stock is very different from yours. WiFi isn't a good solution in areas of very dense population, as interference from neighbouring networks can kill throughput. Traditional European housing stock with thick internal walls made of brick or stone kills WiFi, and the long, narrow shape of traditional British terraces mean that Wifi users can often have several neighouring networks that are closer than their own access point. And retro-fitting Ethernet into a property with traditionally plastered walls, stone floors and no wall voids needs either visible cabling or significant redecoration.By contrast, the traditional American wood-built detached property sitting in its own spacious yard is perfect for WiFi.
ragincajun84 - Wednesday, February 9, 2011 - link
Is this a paid article? It reads like an ad for Sigma and G.hn. It barely mentions the other silicon players yet raves about Sigma demos and slideware. Sigma has not brought a single powerline product to market and G.hn has been hyped for 5 years and still has no products on the market.ganeshts - Thursday, February 10, 2011 - link
I believe I have pointed out enough places where G.hn is yet to catch up or will have potential problems.I wrote the article after seeing Sigma's demonstrations both at their HQ in CA as well as their demo at CES. It really works in the demo situation / lab. Any new company will have teething trouble, trying to get into the market and convince customers. That doesn't mean the technology is not good. Yes, G.hn will have to present a really valid case to the concerned people to shift from HomePlug because HomePlug is very well established and mature.
At CES, after seeing what Atheros and Sigma had to offer, I believe Sigma has taken bigger strides and that is why 75% of the article is focused on them. (They have taken bigger strides because G.hn hasn't seen mature silicon yet). This article wasn't meant to be a coverage of the PLC industry as a whole.