The world's top-four television makers have started working with other companies to develop a wireless replacement for the cables currently used to connect home electronics.

Under the umbrella of the WirelessHD Special Interest Group the companies want to have the first version of the standard completed in the first half of 2007 and begin licensing soon after. That could mean the first products using the technology appear on the market sometime during 2008.

The group includes Samsung, Sony, LG Electronics and Matsushita Electric Industrial (Panasonic), which are the top four TV makers by revenue according to DisplaySearch, and NEC, Toshiba and chip design company Sibeam Inc.

WirelessHD will use an unlicensed portion of spectrum around 60GHz and should be able to support gigabit-per-second class streaming of uncompressed full high-definition video (1,080 lines of resolution, progressive scanning) over a distance of several metres. At least two streams should be possible in the average room without causing interference, said Lianne Caetano, executive director of WirelessHD in a telephone interview.

The system is envisaged to allow video and audio to be sent back and forth between consumer electronics devices such as camcorders, game consoles and DVD players, and with a television set. A back-channel would allow for control signals or other data to be sent from one device to another. Using this back channel WirelessHD is also chasing the elusive goal of a single remote control that can work with all devices in the room.

The group chose the 60GHz spectrum for a couple of reasons, said Caetano. "No other spectrum available right now has this much available bandwidth, it's a monstrous amount of bandwidth. That's what helps us get these multiple gigabit data rates. It also has a really high allowable transmit power, in the US it's eight watts."

The frequency is much higher than those used for other systems, such as wireless LAN, and brings with it some technical problems that will have to be overcome before it can be commercialized.

Signals at 60GHz are subject to different propagation characteristics than those at lower frequencies and communication starts to lose its robustness if it is not line-of-sight. In a living room, line-of-sight might not always be possible, especially as people move around the room, so the group is already planning to add smart antenna technology and error-correction algorithms to help ensure smooth pictures are always delivered.

"We haven't yet said exactly how many signals in-room you can have but it will be at least two for 1,080p and it will be much higher for other types of signals," said Caetano. To date the group has managed to get the system working with an interlaced 1,080i signal, she said.

WirelessHD might also have to play with a myriad of copy-protection systems currently employed by different devices. The WirelessHD system will employ an existing copy protection but that system hasn't been fixed yet, said Caetano.

It will also likely have to compete with a number of other cable-replacement technologies. Some of these are further on in development and have already been publically demonstrated, but with backing from leading TV set makers WirelessHD might have a head-start.

The group won't be at the upcoming International Consumer Electronics Show (CES) in January next year, but some member companies might be demonstrating the technology, said Caetano.