The good news in home networking is that many companies and consortiums are gearing up products and initiatives to reliably shuttle voice, video and music around the house. The bad news is that many of the upcoming products and initiatives attack the core problem of quality-of-service (QoS) in slightly different ways.

For example, wireless vendors like TZero and Metalink are shipping components for sending multimedia over ultrawideband and 802.11n links, respectively, and each company uses some proprietary secret sauce in its approach to QoS (pronounced kwahs). Meanwhile, the ad hoc industry groups defining separate wired home networks for coaxial, power line and phone lines are not coordinating their approaches to QoS either.

Service providers have their own silos. Cable Labs considers QoS to be one of the most important aspects of its ongoing work in defining home networks for cable TV providers. The Home Gateway Initiative (HGI) takes a similar view with its separate work deploying Internet Protocol television (IPTV) networks for telephone companies.

Two independent groups are trying to bridge the gaps, working at opposite ends of the technology spectrum. But the work of the UPnP Forum (which promotes the Universal Plug and Play protocols) on an application programming interface (API) and the IEEE 802.1 Audio/Video Bridging Task Group (AVB) on a revised media access controller will not be complete for at least a year.

It's not clear how well the two technologies will work together, but both efforts are being closely watched by engineers as a possible remedy to the problem of fragmentation. "Everybody has a different notion of what QoS should be, but if you've got more than one QoS, you haven't got any," said Glen Stone, senior director of the Strategy, Standards and Architecture Division at Sony.

The problem is that many players--especially TV service providers--see the capability of delivering multimedia over a home net as a competitive advantage or core competency. "They fundamentally want to have control over QoS in the home net because if something goes wrong, people will call them for support," said Stone.

Problems only get worse with the move to high-definition TVs and DVDs. "We are focused on the HD experience, and that content really exacerbates the QoS issue," said Gary O'Neall, vice president of global set-top development for Motorola.

"You don't see wireless video from Scientific-Atlanta yet because we believe people would get frustrated when they see effects like macro blocking," said Dave Clark, director of product strategy and management for the SA set-top group, which is now part of Cisco Systems.

In late October, six top consumer electronics companies said they would solve the wireless high-def problem by throwing yet another option into the ring--60-GHz radio technology. The WirelessHD group brings its own approach to QoS, which will be detailed in a spec that the group will make public early in 2007.

"Most engineers are not yet thinking about QoS as a network service linking different companies' products over different network types," said Stone. "Sadly, we may have to choose a lowest-common-denominator mechanism so everyone can map to it," he added.