G.hn enthusiasts believe it will become the dominant home networking standard over existing wiring, displacing the multiplicity of technologies which now compete with -- and interfere with -- each other. We first wrote about G.hn more than a year ago in The Everywire Standard: G.hn and HomeGrid Forum ( www.broadbandhomecentral.com/report/backissues/Report0803_4.html ).
But there are many G.hn skeptics. Not surprisingly, these include the trade organizations providing the leading home networking technologies over existing wiring--MoCA for coax and HomePlug for powerline--and most of their members. Over the past two months, we've discussed G.hn with many of these skeptics.
Before we go into the details, here's a summary of their positions:
Most companies affiliated with MoCA and HomePlug say they would welcome a unifying standard, but could support G.hn only if it supported back-compatibility and provided a major step forward in performance. Some of them are working actively within G.hn trying to effect changes before the standard is completed this year. Others think G.hn is irrelevant and are focusing their attention on their own next-generation standards.
HomePlug: G.hn is Fracturing the Industry
The HomePlug Powerline Alliance (HomePlug) is focused on powerline networking, largely for retail markets. Over the past few years, many service providers have deployed HomePlug -- mostly for high-speed data networking in North America, and for IPTV in Europe and Asia.
To better understand HomePlug's positions on G.hn, we recently met or talked on the phone with:
The powerline networking industry has long suffered from having three mutually-incompatible standards (see Powerline Networking--War of the Standards ( www.broadbandhomecentral.com/report/backissues/Report0702_5.html )). It has spent more than four years hammering out the IEEE P1901 standard, now moving toward publication. HomePlug views G.hn as yet another standard that is incompatible with the installed base of HomePlug devices--and with P1901. It still hopes there's time to remedy this before the standard is locked in.
Intellon: Make HomePlug AV "the bridge to drive G.hn success"
We visited Intellon's Orlando headquarters to meet with Charlie Harris and Rick Furtney. Intellon is the primary provider of HomePlug semiconductors, and until now the only provider of HomePlug AV chips. Some of Intellon's chips go into devices sold at retail, others into devices sold to service providers. They showed us a chart listing 48 service providers currently deploying Intellon-based HomePlug products for data and video networking. More than two-thirds of Intellon's current revenue comes from these service provider products; more than half of their revenue comes from Europe.
Charlie and Rick stressed that Intellon is strongly in favor of industry standards, especially those coming from formal standards development organizations (SDOs). Intellon created the baseline technology for HomePlug 1.0, and is a major technology contributor to HomePlug AV, IEEE P1901, and ITU-T G.hn. While they feel the promise of G.hn is very positive and worthy of support, they say the reality is not fulfilling the promise: "The current G.hn spec is likely to prolong rather than resolve the standards uncertainty in powerline and coax wireline communications." They think that "as service providers and other customers come to recognize the realities inherent in the spec, support for G.hn will decline."
They pointed out that HomePlug AV has a lot of momentum. The day we visited Orlando, Gigle Semiconductor announced that two of its chips had just achieved HomePlug AV certification, providing an alternate AV chip supplier for the first time. Charlie expects there will be six AV chip suppliers by the end of 2009, providing a robust ecosystem. HomePlug is now working on AV2, which will provide a substantial performance improvement over AV.
Intellon believes the US drive to "smart energy" will create a significant new market opportunity for HomePlug. Energy companies need a link between the electric meter (typically outside the house) and devices inside the house. While some companies are looking for wireless solutions to play this role, others think powerline networking would be a better choice for robust communications. Nine major energy companies are already members of HomePlug, and are working toward "an interoperable HPAV-lite for smart energy" based on IEEE P1901. This will complement HomePlug's data and video networking markets.
Intellon thinks "G.hn is several years away from real volume deployments" and expects there will be a large installed base of HomePlug AV products before any volume delivery of products based on G.hn. If G.hn is a competing standard with little or no performance improvement, it will have to take market share away from HomePlug AV - and Intellon says "There is no history of an SDO specification replacing a successful incumbent technology with same performance technology."
They say "G.hn does not coexist or interoperate with HomePlug AV" which poses a significant deployment problem for both existing and new customers. The next-generation AV2 product will have a significant performance advantage over G.hn, is fully interoperable with the current AV product, and will have at least six silicon providers. For the many service providers who have already deployed HomePlug, AV2 should provide a much better choice than G.hn as now defined.
Intellon hopes that G.hn will redress these issues before the standard is finalized later this year, and is actively participating in the G.hn process with the hope of doing so. They say that if G.hn were modified to be interoperable, HomePlug AV could provide "the bridge to drive G.hn success."
Arkados: "Bring G.hn in line with HomePlug AV and P1901"
We've met with Oleg Logvinov, CEO of Arkados, many times over the past decade, and recently discussed G.hn with him on the phone. Arkados supplies HomePlug 1.0 silicon, and last year announced a deal with STMicroelectronics to develop and manufacture a HomePlug AV System-on-Chip (SoC) including support for IEEE P1901. Oleg has been involved with HomePlug from the beginning, served for several years as President, and is now Chief Strategy Officer.
Oleg has long advocated unified standards for powerline networking, and has been an active participant in HomePlug, P1901 and G.hn. Like Charlie Harris, he's disappointed that G.hn's reality falls short of its promise. In our phone call, he said "When service providers turn their attention to what was done in the G.hn group, they’ll see it was a short-sighted move. You have technology that’s basically 90% HP AV, with artificial changes making it inferior to HP AV." He thinks service providers should "influence the G.hn group to revisit the recommendation to bring it in line with HomePlug AV and P1901 -- to lay the foundation for success of technology, not failure."
HomePlug supporters disagree with G.hn claims to outperform HomePlug AV. Oleg explained the disparity this way: "HomePlug AV runs in 2 to 30 MHz. G.hn spans 2 to 30, and claims the use of frequencies above 30. The performance of AV and G.hn in 2 to 30 is pretty similar – G.hn will be somewhat poorer because it’s not optimized for powerline. The ability to transmit above 30 MHz is questionable in powerline due to the power spectrum density profile specified by the regulatory bodies -- have to transmit at lower power. There’s not much benefit for the wider frequency band at this point."
Oleg hopes there is time to change G.hn to bring it into conformance with HomePlug and P1901. He said there are two primary technical issues: the forward error correction (FEC) technique, and the preamble. G.hn is using a different FEC technique than the one used in HomePlug, and a different format for the preamble. G.hn should change these to conform with HomePlug AV/P1901, so HomePlug AV and G.hn devices would avoid interfering with each other, and ideally would be able to work together.
If G.hn doesn't make these changes, Oleg thinks it will find it hard to compete with HomePlug AV: "It doesn’t outperform HP AV, why would people be attracted to a technology that is so late to the market and is not interoperable with millions of already deployed devices?"
MoCA: G.hn is Irrelevant
The Multimedia over Coax Alliance (MoCA) was created to serve the needs of video service providers in markets where coaxial cable is widely deployed for TV distribution in the home - primarily markets with high penetration of cable-based subscription video, such as North America.
To better understand MoCA's position on G.hn, we recently met or talked on the phone with:
The original MoCA 1.0 operated at a throughput of about 100 Mbps; the current MoCA 1.1 extends throughput to 175 Mbps. MoCA is now developing the specs for MoCA 2, which will up the speed to 400 Mbps with an extension to 800 Mbps.
Until recently, only Entropic could provide chips certified for MoCA (both 1.0 and 1.1). At CES 2009, Broadcom announced the addition of MoCA to its latest SoC chips for set top boxes ( www.broadbandhomecentral.com/report/backissues/Report0901_6.html#link6a ), and recently obtained MoCA 1.0 certification for those chips.
MoCA has been quite vocal in its objections to G.hn. They say that ITU-T doesn't include most providers of television services in the US, that the lack of backward compatibility forces existing vendors and service providers to "start from scratch", and that G.hn's "claim of working over three very different mediums" is "dubious and still to be proven".
MoCA representatives point out that nearly all US video service providers -- both satellite providers, most cable operators, and Verizon -- have committed to MoCA (AT&T is the exception). Verizon and the satellite companies have already deployed MoCA in substantial volumes.
The cable industry is starting to deploy "multi-room DVR." Cable equipment manufacturers include MoCA in their latest set top boxes. Major cable operators have started deployment and are ramping up quickly.
By the time G.hn devices are available in volume, these service providers will be supporting tens of millions of homes with MoCA 1.1. When they need higher performance, they will almost certainly move to MoCA 2.0, which is backward compatible with MoCA 1.1 and much faster. Since G.hn is not backward compatible, and is unlikely to perform any better than MoCA 2.0 in the real world, MoCA thinks the US service providers will "have no interest in G.hn."
Nevertheless, some MoCA members would like to see a unified networking standard. G.hn is sufficiently similar to MoCA that it would not be hard to make it fully compatible. Last year, they pushed for interoperability between G.hn and MoCA, and lost. Now they think G.hn is largely irrelevant for coax networking in North America.
For More Information
We have written about home networking since the first issue of this newsletter more than nine years ago. Our Topical Index: Home Networking ( www.broadbandhomecentral.com/guide_homenet.html ) provides access to our articles on all aspects of home networking, organized by technology.