Air Time: Airgo's True MIMO Gen3: Breaking New Ground in Wireless Performance

As is the case with most information technologies, performance thresholdshave played an important role in driving the wireless network market. It wasn'tthat long ago that breaking the one-megabit performance barrier was viewedas a significant technical event. And when 802.11b surpassed the 10-megabitdata rate provided by Ethernet, wireless LANs gained significant marketcredibility (even though actual throughput was much lower than Ethernet).The latest barrier to be broken by the wireless engineering team at AirgoNetworks is 100-megabit Fast Ethernet, the industry standard networktechnology connecting most desktop computers to home and enterprisenetworks.

Yes, we've seen a number of vendors offer wireless networking thatpurportedly runs at speeds in excess of 100 megabits. But the throughput ofthese systems is less than half that number, making it significantly slower thanFast Ethernet in real-world environments. Plus, the added performancesometimes comes at the expense of compatibility with standards-based802.11. Still, pushing the performance window is good business, and it has beenproven to move boxes through the retail channel.

Don't confuse previous high-performance wireless technology with that offeredby Airgo. The upstart wireless chip developer is breaking new ground withradio-based networking that defies conventional wireless wisdom and sets thestage for future improvements in performance of all wireless systems, from thehome to the enterprise to the metropolis. Airgo's latest True MIMO Gen3product offering, sampling in volume today and expected to find its way intoshipping products by year-end, touts a maximum data rate of 240 megabitsper second and sustainable TCP throughput in excess of 120 Mbps. That'stwice as fast as the company's second-generation chip and faster, using real-world applications, than Fast Ethernet. If that's not enough, how does 15%cheaper and 20% more power efficient. It's the hottest wireless technologycurrently available and it foretells a very interesting future.

Airgo's primary markets are consumers and small to medium offices, a smartbusiness decision that leverages mass-market product volumes. I've longargued that the vast majority of home users don't really need this level ofperformance. After all, most are sharing a broadband connection that topsout at 5 Mbps best case. Still, given the choice, many consumers will opt forfaster rather than slower, provided the additional cost is modest. If pasttrends are any indication, look for $100 routers built around True MIMO Gen3sometime in 2006.

While consumers may not need 120 megabits of throughput, what they do needis acceptable performance with transmission range that covers an entire homeor small office. First, while plain old Wi-Fi may indeed be adequate if you arephysically located in close proximity to your AP, it's not unusual to seeWi-Fi's rate reduction algorithms kick in, dropping effective throughput towell under a megabit per second. In addition to offering hot-rod performance,Airgo's MIMO technology leverages the natural effects of multi-pathinterference, maintaining high-speed connections at much longer range.According to Airgo, their real-world testing has shown that in a homeenvironment where the wireless AP is 4 rooms away from the client, traditional802.11g systems fall back to link rates of 2 megabits per second while TrueMIMO Gen3 maintains a link rate of almost 100 megabits per second. That'sgood news for home users as well as users in small and branch offices, wheremaximizing wireless coverage is often a high priority.Alas, this is far from nirvana. Although Airgo deserves credit for making itsproducts backward compatible with existing 802.11 standards, the system'sproprietary design requires Airgo interfaces on both ends of the connection toachieve significant benefits. In addition, the 240-megabit link rate is onlyachievable when two 802.11 channels are bonded together, though Airgo'schannel-bonding technology allows for coexistence with Wi-Fi networksoperating on another non-overlapping channel.

For enterprise users, the writing is on the wall: MIMO is the future. That's aconclusion that may lead some to reconsider large-scale 11g or 11adeployment plans. We don't expect to see much interest in Gen3 amongstenterprise network managers, whose architectural decisions are increasinglydriven by open standards. However, Airgo's latest moves will put tremendouspressure on the 802.11n committee to approve a new high-speed WLANstandard. We'll forgive Airgo for asserting that Gen3 surpasses wired networkspeeds, but it will be a long time before gigabit wireless is a reality. Still, it doesmake the wireless enterprise a more intriguing long-term possibility.