Irrespective of the technical capabilities of the products based on the two standards, it is essential that the adopted standard not disrupt existing installations of products based on other standards. This is especially important for MDUs (Multiple Dwelling Units), where the power lines are shared across multiple residences. One would definitely not want a G.hn device to mess up the operation of a HomePlug device. Considering that HomePlug already has an installed base, and there is no G.hn silicon with consumers yet, we believe that G.hn vendors must ensure that they peacefully coexist with them when it comes to the retail market. The G.9972 component of the standard specifies a coexistence mechanism for G.hn devices.

IEEE P1901 specifies a mandatory ISP (indicated with a star in the above timeline). This Inter-System-Protocol (also termed as Inter-Specification-Protocol in some documents) ensures that a IEEE P1901 device can coexist (with just loss in throughput) with a G.hn device. One must note that the G.hn device must also support the ISP (specified as G.cx). The chipset introduced by Marvell supports G.cx and it should be able to co-exist with IEEE P1901 devices implementing the ISP segment of the specification. In July 2011, Kawasaki Microelectronics (part of the HD-PLC alliance) introduced silicon compliant with IEEE P1901 and also implementing the ISP. Marvell indicated that the 88LX2142 could definitely coexist with such HD-PLC solutions. Note that coexistence implies absence of interference only. It doesn't mean that a UPA device can talk with a device based on G.hn silicon from Marvell.

In the above timeline, I have specifically refrained from indicating the availability of IEEE P1901 compliant HomePlug silicon (despite the fact that many chipsets such as the AR7400 from Qualcomm claim to be IEEE P1901 compliant). We have not found any documentation pointing to the existence of the mandatory ISP in it. (The AR7400 does support IPP (Inter-PHY-Protocol) which, at first glance, seems to enable them to co-exist with HD-PLC silicon). Note that the existence of ISP can be proved when it interoperates with a G.hn device, and G.hn devices are currently not in the market. Unless an interoperability / coexistence fest is organized with both IEEE 1901 silicon and G.hn silicon, this can't be completely proved or disproved.

 

Marvell's G.hn Transceiver Chipset Sigma Designs's Kitchen Sink Approach
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  • Anosh - Tuesday, September 27, 2011 - link

    Considering that unless you use the same generation of homeplugs in your house the speeds you get are low and kind of unreliable I believe people will look at G.hn as if it's another/new generation of homeplug. In which case the huge install base of homeplug wont matter very much. In other words it's a matter of time before G.hn replaces homeplug unless homeplug manages to crank up the speeds and keep issues across generations to a minimum. Which historically they haven't done. Reply
  • Zak - Tuesday, September 27, 2011 - link

    I thought this tech was dead, killed by WiFi. This is the first mainstream article I've seen in years. I've only known a handful of people who tried this tech at home, lured by it's simplicity, and it was always a failure due to unreliability of the equipment and problems with connectivity. I'd much rather recommend investing some time and effort in running network cables or extra access points/repeaters for WiFi (or combination of both). Reply
  • Denithor - Tuesday, September 27, 2011 - link

    You really need to catch up on your tech before running off at the mouth like this.

    I use a 1 generation back Trendnet kit at home with perfect connectivity. Full internet speed on my office pc (shared from htpc in the living room like 50 feet away) with no latency issues or anything. Completely able to stream HD video, game, etc.

    Completely different from my experience with WiFi across the same rooms, dropped signals, bad ping times plagued me constantly...
    Reply
  • Zoomer - Tuesday, September 27, 2011 - link

    Yes, dedicated ethernet will always be best, followed by non dedicated wiring, then wireless. Wireless by its nature will be the most unreliable.

    Wireless can be very unreliable and very slow in densely populated areas, ie. apts in cities. When tens of different & possibly misconfigured APs are crowding the same channels, good luck.
    Reply
  • akedia - Tuesday, September 27, 2011 - link

    Years? How 'bout three weeks ago on this very site: http://www.anandtech.com/show/4695/handson-powerli... Reply
  • akedia - Tuesday, September 27, 2011 - link

    Or two days?: http://www.engadget.com/2011/09/25/switched-on-no-... Reply
  • kolepard - Tuesday, September 27, 2011 - link

    The control ceded to service providers is very anti-consumer and a huge negative if this report is correct:

    http://www.engadget.com/2011/09/25/switched-on-no-...

    The most bothersome section is:

    "The service provider may then request that you call them for permission to install, may provide a portion of the bandwidth available over the power lines, or may even flatly tell you that you can't use the adapters. G.hn equipment providers are working with service providers to encourage a more relaxed stance, but operators reserve the right to do what they want."

    Given the alternatives available, I think this my seriously impair adoption.
    Reply
  • Zoomer - Tuesday, September 27, 2011 - link

    One could just cancel the service. Reply
  • lowlymarine - Tuesday, September 27, 2011 - link

    You say that as if your local cable provider isn't a monopoly on broadband for a huge percentage of Americans. Even if they aren't, it's usually not much of a choice anyways. Where I live, you can get 40/5 cable service through Bright House for $75/month that typically hits the advertised speeds, or 6/1 DSL through AT&T for $50/month that usually only hits about 3/0.5. Even without the massive disparity in service, something tells me AT&T wouldn't be more permissive than...anyone, really. Reply
  • ganeshts - Tuesday, September 27, 2011 - link

    Irrespective of whether it is G.hn or IEEE P1905 which gets adopted, I think service providers will be able to do whatever is mentioned in the Engadget article with respect to future home networks.

    /* Start of rant */
    The only solution is to make the service providers into dumb pipe providers. Just use them for the Internet service and don't get any video or telephone service from them. Yes, one may complain about live sporting events and other similar stuff, but it is not difficult to envisage them becoming available online on a subscription basis (you pay directly to the broadcaster and not the middleman like Comcast or AT&T or any other service provider).

    I personally believe that the way people watch TV will undergo a sea change in the coming years. While local TV channels (particularly of the news variety) will remain free-to-air and stay socially relevant, linear TV in any other form will be dead (strong words :P). I don't think the current TV service providers (be it cable or satellite or IPTV) are going to be relevant when linear TV goes out of fashion. Consumers must put these providers in the place and just haggle with them to provide bandwidth and access to the Internet in an unfettered manner. Then, there is the whole big issue of the governments supporting the consumers in this aspect, but that is a subject for another rant on another day...
    /* End of rant */
    Reply

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