In our previous issue, we introduced powerline networking and HomePlug. Despite our concern about market confusion in introducing yet another home networking technology, we believe that since most devices are already plugged into electrical outlets, this technology makes a lot of sense for the mass market and the stationary devices in the home. One of our questions was how well these products actually work and so we tested a sampling of HomePlug products in our own home to gain anecdotal experience. We also interviewed representatives from the HomePlug alliance to understand how they intend to promote HomePlug products, given the mind share and shelf space already occupied by Wi-Fi.
We've subjected HomePlug products from three companies to a series of in-home tests - in fact, we wrote part of this article on a desktop machine connected to our server and the Internet through HomePlug. We also interviewed many of the key players developing and marketing this technology.
We came away from our testing and discussions with the strong belief that HomePlug could play a major role in consumer networking. Our tests confirmed our initial conclusion that HomePlug would be "a good solution for connecting multiple PCs to a cable or DSL modem"; indeed, we think HomePlug is a good fit for additional applications, including telephony and audio distribution. It falls short for video distribution, but that's still several years away as a mass-market requirement.
We ran into several problems during our testing and interacted with many of the vendors about them. From the responses we got we are assuming that most should be resolved in the next generation of chips that are already being integrated into products for later this year. The most serious problem - assuring seamless interoperability between "HomePlug"-branded products - is being studied by the HomePlug organization and we hope it will be resolved soon.
Although we were impressed with HomePlug even when testing first-generation products, we are not convinced that the market can absorb yet another approach to "no new wires" networking. Now that HomePlug products are becoming available, the participants face a major challenge to get attention in a very crowded market.
HomePlug PowerLine Alliance The HomePlug Powerline Alliance was formed more than two years ago to create a common specification so that products from different companies would be interoperable and so they could be marketed with a common logo. The Alliance released its HomePlug 1.0 specification in June 2001 and the consortium members have been working to develop consumer products.
We interviewed Tom Reed, the President of the Alliance, several times by telephone and in person. We also interviewed Larry Yonge of Intellon, chair of the HomePlug technical group; Christian Joly, Intellon's Senior VP of Marketing and Business Development; and Brad Warnock, Director of Marketing at Phonex Broadband. Our previous issue summarized our interview with Graham Wilson of Cogency, chair of the HomePlug marketing group.
We discussed the interoperability issue with technical and marketing people. They want the "HomePlug" label on a product to connote "interoperability" and said that they plan to take action to assure that devices from different vendors will work together seamlessly.
We were told that the initial positioning for HomePlug will be for sharing the broadband connection and for audio distribution, and that later generations will support higher speeds and will handle home video distribution. We were also told that HomePlug products would be price competitive with other approaches to home networking, and would be available through many distribution channels including online, retail, and through service providers. Retail will be initially focused on several key markets.
We asked the marketing people how they intend to sell HomePlug products against Wi-Fi wireless, which has achieved substantial market acceptance as a workable solution for connecting one or more remote PCs to a broadband modem. We were told that the positioning might well be "HomePlug works where wireless doesn't".
Summary Of Our Test Results
We tested HomePlug products from three companies - Asoka USA, Phonex Broadband, and ST&T xNetworks - and also examined a product from Valence Semiconductor. Other HomePlug products are currently on the market from Linksys, Netgear and others. Since all current products are based on the same chip from Intellon, the results from our tests should be representative of other current products. Our preliminary evaluation of a pre-release product based on a Cogency chip suggested that products based on this chip will provide comparable results.
We tested in only one home, so our conclusions should be considered as indicative but not definitive; we wouldn't be surprised if tests in another home were different. We understand that the HomePlug organization will publish the results of its extensive home testing, and we're looking forward to comparing the results.
We tested two-node networks with HomePlug Ethernet bridge adapters from the same company; two- and three-node networks mixing different company's adapters; and a network with a USB adapter and an Ethernet bridge. These networks all used one HomePlug Ethernet bridge as the "master" adapter - connected to the Ethernet switch sitting between our broadband modem and our desktop PCs - and one or more "mobile" adapters connected to remote portable and desktop PCs. The master adapter was plugged into a "good" outlet after several false starts (see below) and we carried a portable PC with a mobile adapter around our house to test at a variety of outlets.
We performed quantitative measurement of network speed by creating a diagnostic to precisely time the transfer of a large file between PCs. This gives transfer rates substantially lower than "raw" network speed but we believe provides a realistic comparison between different networking technologies.
More information about the tested products, the details of our testing approach and results are available on our website at http://www.bbhcentral.com/bbhl/homeplug.html.
Here's a summary of what we found:
Performance and Speed
What Makes Outlets "Good" or "Bad"?
We spent a lot of effort trying to understand why some outlets worked much better than others. We read the product manuals, discussed this with many vendors, and tried to decipher our test results for clues. We wanted to read the HomePlug specifications, but they are considered proprietary and were not available to us. In the absence of understanding just how the technology works, it's pretty hard to deduce why some outlets were particularly bad.
Since the tested HomePlug devices are all based on the same Intellon chip, it's not surprising that they were largely compatible. Later this year, devices based on Cogency's chips will appear on the market, and products will come to market with Intellon's new chip; this offers plenty of opportunities for additional compatability issues. Consumers will be very disappointed if the HomePlug logo fails to fulfill its promise of product interoperability.
HomePlug Products Tested We thank the HomePlug PowerLine Alliance for coordinating our contacts with vendors, the manufacturers for providing adapters and telephone support during our testing, and the chip vendors for their help in reviewing our test plan and explaining why some outlets worked better than others.
We tested both Ethernet and USB adapters from Asoka USA - the PlugLink Ethernet Bridge PL9610-ETH shown on the left and PlugLink USB Adapter PL9710-USB on the right. See our previous article for background on Asoka.
Just before going to press, we received a pre-release product made by ST&T - a USB Wall Adaptor U22. Unlike the other units, this is designed to plug directly into the wall; it is the first production unit based on the Cogency chip. We will report on our tests of this unit in the next issue.
We received a PCI Evaluation Kit VK6001-EVB1 from Valence Semiconductor, but ran out of time before we were able to evaluate it. Unlike the other units, this is configured as a PCI card to be installed in a desktop PC; a power cord connects it to an outlet.
More details of these products and our tests are posted on our web site at http://www.bbhcentral.com/bbhl/homeplug.html .