MoCA (Multimedia over Coax, which has been adopted by some service providers for implementing multi-room DVRs) and HomePNA (originally for phone lines but later expanded to coax cable as well). At least three dueling standards have also sought to bring high-speed connectivity over electrical wiring. HomePlug, the most successful of these, has had several iterations. The latest – HomePlug AV – is rated at a theoretical throughput of 200 Mbits/sec. However, power line technologies have been held back by high prices and occasional interoperability problems.
But a new approach seeks to be the one protocol to rule them all, operating over phone lines, power lines or coax. Dubbed G.hn, the ITU standard promises up to 1Gbps theoretical throughput, with real-world usage over electrical lines expected to reach between 250Mbps and 400Mbps. If that sounds appealing to you, you're not alone. Service providers like the idea of G.hn since it allows them more flexibility than previous efforts. In fact, they like it so much that -- despite G.hn's capacity -- they have insisted on quality of service standards that could limit or prevent consumers from installing it themselves after they buy adapters from retailers.
Let's say your local pay-TV provider outfits your home with G.hn power line adapters to stream high-definition shows between two DVRs. A few months later, you purchase a couple of G.hn bridges to hook up your bedroom PC to your living room Blu-ray player to stream your own high-definition videos. The G.hn adapters that the service provider installed will recognize the new equipment. 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.
Savvy home networkers will find a few ways to work around the service provider prerogative and still tap the bandwidth of cables already in the home. If, for example, the service provider chooses G.hn using coax cables, you are free to use one of the other two methods (phone line or power line) without restrictions. Or you could still use a technology other than G.hn. Going back to power line, the next version of the HomePlug standard is expected to coexist with G.hn. Finally, you could opt for a pay-TV provider that doesn't use G.hn if you have a local choice available.
G.hn is expected to appear in devices before the end of the next year, rolling out to service providers first, consumer electronics companies second, and finally to networking products aimed at retailers and consumers. It could deliver a promising complement to WiFi; but if your service provider puts it in your home before you do, remember to put sugar on top of your "pretty please" when you try to install it.
Ross Rubin (@rossrubin) is executive director of industry analysis for consumer technology at market research and analysis firm The NPD Group. Views expressed in Switched On are his own.