Powerline Networking with the Western Digital Livewireby Ganesh T S on August 24, 2010 7:50 AM EST
Most of the CE devices in the market today connect to the Internet as well as the home network. While many of them have the capability to connect to wireless networks, it is not really a great option for many of the bandwidth hungry units. Examples of such units include Netflix streaming TVs or media streamers such as the WDTV Live. Many a consumer has been frustrated by the incessant buffering and playback stuttering while putting wireless networks (even of the 802.11n variety) to use in such scenarios. Further, not all consumers have the luxury of a flawless wireless network in their residence. Running an Ethernet cable around the house is one option, but it is too cumbersome and costly for many. In this scenario, the electrical network within the house looks like an unexploited part of the equation.
The HomePlug AV standard aims to deliver networking capabilities around the house by taking advantage of the already existing electrical wiring. It is the baseline specification for the upcoming IEEE standard (IEEE P1901). There are other competing standards (we will cover them briefly in the next section), but the product being covered today adheres to the HomePlug AV standard. If you are interested in only finding out how the WD Livewire performs, please feel free to continue reading from the 'Unboxing & Setup Impressions' section onwards. On the other hand, if you want to learn about the history of powerline networking and the companies active in this space, this, as well as the next section, will be of interest.
Wikipedia traces the history of the HomePlug standard quite well. We have been following the consumer powerline networking area over the last 4 or 5 years, and realized that there is only one chipset vendor shipping any appreciable amount of chips in this space. Intellon, acquired by Atheros towards the end of 2009, is the brain behind almost all the powerline network adapters shipped in the last few years. Belkin claimed a 1 Gbps powerline adapter last year based on the Hispano-Scottish startup Gigle Semiconductor, but the reviews indicated that it performed no better than the 200 Mbps chipsets supplied by Intellon. When Western Digital contacted us to review their first product in this space, and indicated that the PHY rate was at 200 Mbps, we had little doubt that this would be another unit based on the Atheros (Intellon) chipset. Our suspicions were confirmed later (details can be found in the 'Livewire Internals' section).
In the 2010 CES, Atheros / Intellon introduced their fourth generation HomePlug based chipset, the AR7400. As the release indicates, the AR7400 is supposed to operate at a PHY rate of 500 Mbps for powerline applications, but gets a boost to 700 Mbps over coax cables. However, units based on the AR7400 are yet to hit the market. All Atheros/Intellon based products shipping currently are based on the third generation product, the INT6400.
The first generation chipsets introduced way back in 2001 had PHY rates of 14 Mbps (the real throughput was much lesser). The second generation products had a PHY rate of 85 Mbps, while the INT6400 third generation products ups this to 200 Mbps. With the advent of HD media streaming (and multiple streams, at that), 200 Mbps PHY rates are barely enough, and Western Digital has wisely decided to advertise the Livewire kit as being meant for sharing an Internet connection. That said, an idea of the effective bandwidth available also indicates the suitability of the product for data and media transfer within the home network.
As already indicated, the WD Livewire product is based on the HomePlug standard. Are there any other standards available for networking with already existing cables? Do they work, and are they shipping? We will cover this in detail in the next section.