Home networking is an interesting consumer electronics niche that now affects most homeowners, especially if they have a PC with high-speed Internet access or the need to interconnect multiple TV sets, DVD players, digital video recorders (DVRs), and the like. The clear home networking champion, at least for PC Internet access, is Wi-Fi. It’s easy to implement and usually covers the whole house, allowing multiple PCs and laptops to use the high-speed DSL or cable service. The lack of wires makes it a joy.
Yet other home networking solutions out there also focus on the multimedia aspects of consumer electronics. The Mulitmedia over Coax Alliance (MoCA) uses the installed cable TV coax in your walls to interconnect TV sets and other multimedia devices without adding any extra wires. Home PNA is another option, using the installed telephone wiring (ADSL/VDSL) and/or coax. Then there’s the powerline networking option.
This solution puts orthogonal frequency-division multiplexing (OFDM) on the ac powerline for high-speed data transfers over the installed power wiring. Again, there are no new wires. The standard ac outlets are your network connections. That has to be as convenient as wireless, since every room or area in your home probably has multiple ac outlets. Yet the powerline networking segment of home networking is in a muddle and not doing as well as it could.
Standards Muddle
There are four or five (depending how you consider them) competing powerline home networking standards—the HomePlug AV standard, the High Definition Power Line Communications (HD-PLC) standard, the Universal Powerline Association standard, the IEEE P1901 standard, and the new ITU G.9960 standard, also known as G.hn. The ITU standard is still in development, so there’s no supporting silicon yet. However, all the other standards have semiconductor company support as well as end products in the market.
It’s hard to say who’s making any money in this niche, but my guess is that no one standard has the critical mass that would make it overwhelm the others or become the single owner of the home networking space. The closest one to such a goal is probably HomePlug AV, as the HomePlug Powerline Alliance has been around the longest (2000) and has more members (70+).
But there are so many other competitors in this arena. It is just like so many other standards battles in the communications field—lots of technologies, ideas, patents, and other intellectual property and a major stubbornness that reflects that ever present “not invented here” or “mine is better than yours” attitudes. It’s business as usual, but multiple standards lead to marketplace segmentation, customer confusion, and certain interoperability of products.
The result is that this technology doesn’t live up to its potential and gives away the business to other more clear-cut single standards like wireless, MoCA, or HomePNA, all of which are already pretty well entrenched. Yet isn’t multiple standards the American way? We live with the effects of competition every day, though the outcome isn’t always optimum for the competitors. But getting the competing standards bodies to come together and compromise is a real challenge.
The IEEE P1901 effort was an attempt at compromise to bring the HomePlug AV and HD-PLC technologies together. HomePlug AV uses fast Fourier transform (FFT) OFDM, while HD-PLC, invented by Panasonic, uses wavelet OFDM. Of course, they’re incompatible. However, the P1901 standard has dual physical layers (PHYs) and co-existence features. It doesn’t seem wise for anyone to make a chip that will do both, but who knows what someone will do with it? I heard that the P1901 standard will add some conditions to accommodate the new G.hn standard, whatever that means.
As for the ITU standard, I have been unable to find out why this whole effort got started. With so many existing standards, why take a start-from-scratch approach? Who will support it after others have invested fortunes in silicon design and marketing? What were they thinking? Is the potential size of the powerline home networking market big enough to support one more competitor and warrant all much investment? With the consumer market as a target, it may be.
The HomePlug View
HomePlug president Rob Ranck said the G.hn effort further fractures the industry by introducing one more standard that isn’t compatible with the installed base. Further, Ranck said the forthcoming higher-speed HomePlug AV2 standard would be available before G.hn and backward compatible with AV and P1901 products. It is estimated that there will be about 60 million HomePlug and P1901 devices installed before G.hn products hit the market.
While HomePlug feels that G.hn may be similar to HomePlug AV, there will be enough differences to make the two incompatible. One good example is HomePlug AV’s use of turbo-code forward error correction (FEC), while G.hn is expected to use low-density parity check (LDPC) for FEC. There are also differences in the protocol preamble. HomePlug is hopeful those differences can be worked out.
One interesting development with HomePlug is its work with the ZigBee Alliance to create a Smart Energy standard for a home-area network (HAN) that can help utilities minimize power usage and save homeowners considerable energy dollars. The powerline and wireless components complement one another to cover large homes and multi-dwelling units. Consumers can achieve considerable savings by monitoring and reporting energy usage.
The subject here is actually about home powerline networking, rather than the medium voltage internet access promised by BPL, some of whose experimental trials were canceled.
That said, even in the "home" environment, there is nothing that keeps the RF signals placed on your powelines from being shared with all your neighbors on the same side of the nearest transformer. This could be a real problem in condos and apartments where a large number of people are sharing the same "pipe". Don't expect any of the claimed signalling rates if there is ever a reasonable amount of market share penetration.
mressler -May 28, 2009
And this is something we should care about? Yes, powerline networking may be a bit more secure than wireless networking, but with wireless networking built in to nearly all computers now, I'd say that this technology is trending towards irrelevance.
Anonymous -May 28, 2009
Powerline networking -- ten years down, ten to go.
Those of us that cared about this for years finally gave up a while ago. It's like Charlie Brown, Lucy, and the football.
ewertz -May 28, 2009
Nothing was mentioned about the trials of this technology that have caused RF emissions interference with radio communications. These trials were subsequently cancelled.
Anonymous -May 27, 2009
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