MIMO technology to boost WiFi networking speed

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Atheros, the WiFi chip company, is pushing 802.11n multiple input multiple output MIMO WiFi as a technology which will double range and increase actual data throughput by six times, despite questions over the technology's attractions.

There are questions over interoperability, over the willingness of hot-spot owners to upgrade and over users' requirements for longer range and higher throughput.

"We're expecting pretty substantial growth for 802.11n. By the end of 2008 we expect to see it in 30 per cent of new, shipped, notebooks," Todd Antes, v-p for marketing at Atheros, told EW.

Last week Atheros introduced its first 802.11n single-chip product. The theoretical data throughput speed is 300Mbit/s. "At close range, ten feet, actual throughput is 60 per cent of that," said Antes. "We have measured 200Mbit/s actual throughput."

That compares to a theoretical 54Mbit/s for 802.11g, and an actual throughput, at close range, of 20Mbit/s.

The range of 802.11n compared to 802.11g is twice as much, according to Atheros.

So far, so good, but, asked about interoperability testing, Antes pointed out that a specification for testing products from different companies had only been agreed by the WiFi Alliance in May.

"Any products that have made it through the WiFi testing exhibit a mandated level of interoperability," said Antes. It is a less than ringing endorsement of 802.11n interoperability.

Furthermore, there is no evidence that users, who basically want to use WiFi for email, Skype calls and downloading printed data, have any complaints about the speeds of 802.11a and g.

So there is no pressure on hot-spot owners to install 802.11n. A further drawback for 802.11n installation is a lack of tools. Installers now have to use tools designed for 802.11a and g.

Since 802.11n is a draft standard, with final ratification maybe a year away, availability of installation tools could be limited for some time.