News

WiFi goes over 100 megabits , doubles range - Airgo

Given the choice of a wireless network that only reached the walls of your study, or one which penetrated to the room next door, which would you choose? And if it also ran twice as fast as its rival? A new silicon startup promises both. But there are questions unanswered ...

Competition in the WiFi silicon arena is heating up; and with Texas already promising 100 megabit performance over 2.4 GHz spectrum, the smaller contestants are having to match the dream. Newcomer Airgo is sampling the dream today. It's not only 108 megabits but it's also twice (or better) the range, they say.

"In head-to-head testing, the AGN100 demonstrated range that was two to six times that of competing WLAN chipsets, resulting in an order-of-magnitude increase in the area covered by each access point," says the release. It will work on both WiFi standards - the 2.4 GHz 802.11g and the 5 GHz 802.11a systems.

The trick is "intelligent multi-antenna transmission and reception technology." This is normally an expensive trick - the chipset is the first mass-market product to incorporate Multiple-Input-Multiple-Output (MIMO) technology.

This is described as "the most sophisticated and highest performance class of smart antenna signal processing" and the announcement claims that the AGN100 "achieves the promise of the pioneering multi-antenna signal processing research that Airgo founders began at Stanford University in 1995."

Is this a good thing?

It is certainly the case that if the Airgo wireless can magically extend the range without breaching regulations about the maximum signal intensity, then many users will want it. Airgo summarises the problems perceived by users today, pretty well:

"The Airgo team has removed all the fundamental technical barriers to WLAN adoption such as spotty coverage, limited range, insufficient speeds, inadequate security, and a confusing array of standards," said Greg Raleigh, chief executive officer of Airgo.

"By resolving all of these difficult problems in a single highly advanced cost effective solution for OEMs, WiFi can finally fulfill the wireless promise of seamless, cost effective and secure home multimedia networks, enterprise data networks and WiFi hotspots."

Not all observers will see it this way. One of the most pressing problems looming for WiFi is the problem of overlapping networks. Increase the number of networks in a neighbourhood, and eventually, you run into a problem where there are just too many signals on the same channel. Anything which doubled the size of a network would turn a minor problem into a major nuisance.

It also remains to be seen how the Airgo antenna system works in practice. Outside America, restrictions on transmit power are far more strenuous, and even a system which improves antenna "gain" is illegal.

Nobody can seriously hope to stop individual WLAN operators from increasing the gain of their own access points. It's too easy to make a high-gain antenna from bits of wire, and it would be impossible to police. But it's quite a different matter to attempt to get a licence to manufacture and distribute a system which inherently increases signal gain.

Airgo's system may be (if it really works as described - and there's no obvious reason to doubt this!) a boon for users of 11a networks in the home. Currently, the 11a signal can only barely get outside the room where the access point is placed, because even the thinnest walls are opaque to a 1 milliwatt signal at 5 GHz. Perhaps, the Airgo 11a chip would penetrate those walls enough to make 11a useable at home.

But by the same token, a lot of network engineers are counting on the fact that 11a doesn't go far beyond the room, to allow them to have far more access points without co-channel interference.

What people will be hoping is that when production level Airgo systems are demonstrated, the "intelligent" antenna can be programmed to avoid these problems. It will be some months, however, before today's sample chips pass into a full-scale production system which can be bought over the counter.

The full text of Airgo's announcement says that "sample products utilizing the AGN100 wireless chipset are now available from Airgo's manufacturing partners to qualified network equipment manufacturers and other original equipment manufacturers," but doesn't say who these partners are.