From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Date: Tue, 17 Jan 2012 14:38:54 -0800 Subject: [ath9k-devel] Any 4x4 MIMO ath9k NICs coming soon? In-Reply-To: References: <4F15AC14.7000703@candelatech.com> <9DD0133D-2D77-4739-B280-B25E5E43ACF1@zinkconsulting.com> Message-ID: <4F15F87E.9090004@candelatech.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org On 01/17/2012 02:03 PM, Galen wrote: > Ben's company focuses on load testing applications, so I assume he's referring to 4 spatial stream systems. 4x4:4 specifically refers to 4 transmit, 4 receive and support for 4 spatial streams. The only commercially available chipset for 802.11n is from Quantenna. > > There are 4x4:3 802.11n chipsets available which use the extra radio for beamforming and diversity, but these are not 4 spatial stream. You get an improvement in terms of RF performance, but the MAC layer and throughput is essentially the same as 3x3:3 solutions like AR9380 and AR9390. Since Ben's application is primarily focused on these layers as far as i know, I assumed he was looking for 4 spatial streams. > > Keep in mind, beamforming and diversity is very much possible within implementations the 802.11n specification. The only thing really novel to 802.11ac is the addition of optional downlink MU-MIMO. > > -Galen > > On Jan 17, 2012, at 1:39 PM, Adrian Chadd wrote: > >> Well, are you talking about: >> >> * 11n 4x4 MIMO? >> * 11ac Multi-user MIMO (where you map stations to separate spatial streams?) >> * other beamforming/diversity stuff? I'm mostly just passing on a question that a customer asked me. I assume they want 4x4 MIMO with 4 spatial streams. I'll look into 11ac as well. I'll also take a look at the quantenna offerings, but so far, Atheros is the only manufacturer that has the driver/hardware support for the virtualization that we need (since way back in ath5k/madwifi days), so I sort of assumed that isn't going to change anytime soon... Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com