Airespace: MISO Soup

Today Airespace Inc. is pointing to some accolades for its coming Intelligent RF Access Point (IRAP), a multi-antenna product the wireless LAN switch startup announced back in May (see Airespace Finds MIMO).

But there is a lingering question about the technology that underpins the IRAP. this involves the semantic and technological nuances of multi-antenna technology. For example, is it really MIMO (multiple input, multiple output), as Airespace itself has sometimes claimed? Or -- is it MISO (multipe input, single output)?

Well, maybe it's both... sorta.

MIMO is a smart antenna technology, which should help to drastically increase the range and throughput of 802.11 networks. The technology works by using a multi-antenna array to transmit and receive multiple versions of the same signal and then combine them at the other end to create a more accurate overall picture than would otherwise be captured by a single data stream, as passed between 802.11 clients and access points.

The Airespace technology doesn't quite work like that. "If you're a purist, you might say its not traditional MIMO," says Alan Cohen, vice president of marketing and product management at Airespace.

Instead, the IRAP uses a four-antenna array, but only receives signals on all those antennas. The device transmists on one antenna -- and it uses software to pick the best signal path. In other words, this means the IRAP is a really a MISO box, Cohen tells us from a hotel room in Japan (how fitting!).

"Sometimes, the word 'MIMO' slips out of our mouths when we're talking about IRAP," says Cohen [ed. note: d'oh!]. "But we mainly refer [to the technology] as 'beam switching.' "

Using this approach allows Airespace to use its IRAP with standard access points and clients, says Cohen. Traditional MIMO implementations require the same technology on both ends of the link to get full speed and range benefits.

So far, Airespace isn't revealing the range and data throughput capabilities of its new box. They may stop being so secretive when it starts shipping in August. An educated guess suggests that the box will offer a better range than traditional access points but won't perform as well as pure MIMO implementations.

— Dan Jones, Site Editor, Unstrung

wlanrunner 12/5/2012 | 1:28:55 AM
re: Airespace: MISO Soup It appears the RF "experts" at Airespace can't even get the story straight on their own products. What else is "slipping out of their mouths" when they are talking about wireless?
wlanrunner 12/5/2012 | 1:28:24 AM
re: Airespace: MISO Soup What's even more amazing is that Airespace has decided to rewrite history. The press release on their website has removed all mention of MIMO while a quick google search will reveal numerous references to the original announcement with plenty of talk about MIMO. The truth is out there somewhere.
rothschild 12/5/2012 | 1:23:01 AM
re: Airespace: MISO Soup remember that this is the same team that sold Cisco the bill of goods called "VOFDM".
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