Dead spots are everywhere. They're those areas of your home or office where, no matter how you position your router or how you point the antenna, you just can't get a Wi-Fi signal. Networking companies have lots of plans for fixing the problem - and many were on show at the Consumer Electronics Show in Las Vegas.

After setup problems, complaints about dead spots are the most common gripes networking companies hear from their customers, company executives said. And those range problems are being exacerbated by the proliferation of Wi-Fi devices that promise to wirelessly stream video between devices such as PCs and televisions.

Almost any Wi-Fi connection, even a weak one, is sufficient to surf the Internet or transfer data. But if distance and obstacles sap too much bandwidth from a network, video images will start to stutter and break up.

"Video is what's causing this [emphasis] on range and higher speed," said Patrick Lo, chair and CEO of Netgear.

The cure for the problem, according to a number of companies, is an innovation called MIMO, short for multiple input, multiple output (read our explanation of MIMO) . The new technology, already on the shelves in routers and adapters from Belkin (reviewed here), uses a number of antennas to send multiple signals as a way to significantly increase the speed and range of a wireless network. Tests of Belkin's MIMO products found they nearly doubled the speed of the fastest 802.11g products and provided superior range.

Some form of MIMO is expected to be included in the upcoming 802.11n specification, the successor to 802.11g in development now by the IEEE. There are in fact two front runners, detailed in this feature, from the TGnSync and WWISE consortia, the latter including Airgo, the market leader in actual MIMO chips.

Vendors such as Belkin are referring to their products as "Pre-N", something which causes hackles to rise with the Wi-Fi Alliance which, naturally enough, refuses an official Wi-Fi .11n label to anything until the standard is finalised (Read both sides of the controversy - Is the Wi-Fi Alliance stifling faster Wi-Fi? and The Wi-Fi Alliance cannot brand Pre-N products!).

What Major Vendors Say
Linksys this week announced its own products that - like Belkin - use the Airgo chips. The Wireless-G Router with SRX WRT54GX has an estimated street price of $200 while the Wireless-G Notebook Adapter with SRX has an estimated street price of $130. Both are available now.

Netgear also plans products using the Airgo chips, which should be out by the end of January. But the company also announced plans for products that it says take an even more sophisticated approach to improving range and speed. Products incorporating BeamFlex technology use seven internal antennas and dynamically change the way they beam Wi-Fi signals to work around obstacles and interference.

Even a dog walking across a room can interfere with a Wi-Fi signal, according to Netgear's Vivek Pathela. BeamFlex routers will fire data at the particular PC or other device requesting it, then monitor how quickly the data is received. If the router detects interference, it'll re-route the next signal, perhaps bouncing it off a wall to avoid an obstacle, Pathela says.

The BeamFlex technology, developed by Video 54, will be included in Netgear's RangeMax products due out in March. The technology can be used with MIMO chips or with standard 802.11g chips.

D-Link's Decision
Officials at D-Link say the company plans to announce products using MIMO technology in the next 30 to 45 days. Its products will use chips from Atheros. That company claims its MIMO implementation is more compatible with existing 802.11g products and is faster than the Airgo chips, both in all-MIMO networks and in networks with a mixture of MIMO devices and other devices using 802.11g.

US Robotics is taking a more conservative approach to extending range. With lots of corporate customers, US Robotics doesn't want to come out with MIMO products that may not be compatible with the final 802.11n standard, according to Senior Product Manager Jim Thomsen.

Instead, the company is pursuing ways to make standard 802.11g products more powerful. US Robotics' Max G line will boost the power of the Wi-Fi signal by 25 percent and increase the maximum speed to 125 Mbit/s. The combined effect is a 50 percent increase in range, Thomsen says.

And the Max G line, expected to be available in late February or early March, will be less expensive than MIMO products, he adds. In the US, a router will sell for $80 and adapters for $70. The line represents "an adequate range solution in the home ... at a much more affordable price," Thomsen says.