Mr. Brough, Thank you so much for taking the time to write a detailed response. Before I wrote my question to the forum I Googled "802.11n beam forming" and only got this hit http://www.thefreelibrary.com/Celeno+Announces+2nd+Generation+CL1800+Beam+Forming+802.11n+Chipset+-...-a0215916941of another company besides Ruckus that is working on bringing beam forming to market.
I wonder if the outdoor AP technology will ever get to the point where beam forming will be put to use. It seems like it would help with frequency reuse if AP's could steer their nulls towards competing AP's and steer their radiated power towards specific customers and away from competing AP's. I think that would be even better than GPS sync since I assume GPS sync works by doing TDM - each AP gets a time slot. Is that right? Or does GPS sync do it's magic by having all AP's transmit at the same time and listen at the same time? Greg On Sun, Feb 7, 2010 at 2:13 PM, Brough Turner <[email protected]> wrote: > Greg, > > At this moment, I think Ruckus is it. As yet, there's been no silicon > support for beamforming under 11n. The one silicon vendor that's been > vocal about beamforming is a startup, Quantenna Communications. They > claim to have a chip that provides both 4x4 MIMO and beamforming, and > claim it's in production. They recently announced that Netgear has > signed up to use their chips > (http://www.quantenna.com/pressrelease-01_05_10.html), but so far no > news of what Netgear products might show up, or when. > > Lacking silicon support for beamforming, Ruckus does beamforming by > "antenna selection." They have an array of 12 antenna elements, a set > of switches and presumably some switchable delays. They claim this > gives them a choice of 4095 distinct antenna patterns. Antenna > selections in this case means they pick which two of the 4095 distinct > beams to use, on a packet by packet basis. They then connect those two > configurations to the two inputs of a standard Atheros 11n 2x2 MIMO chip. > > I can't guess what we'll see for silicon based beamforming in the next > 24 months (beyond the Quantenna chips), but I am optimistic that all > silicon vendors will be driven to do full beamforming in silicon, > eventually. The reason is residential Wi-Fi in apartment buildings > (think of all those 30 story apartment buildings in Hong Kong and > Beijing). When every apartment has an access point, you need > directional to avoid interference from your neighbors. > > I'm sure the VCs that invested in Quantenna expect to sell out to > whichever mainstream Wi-Fi chip vendor doesn't get their beamforming > working in time. I'm just not sure of time frames. > > Thanks, > Brough > > Skype: brough Mobile: +1 617 285 0433 > http://blogs.broughturner.com > > On 2/7/10 6:41 AM, Greg wrote: > > Though the 802.11n specification details beam forming it appears the only > > manufacturer to explicitly market their product as doing beam forming is > > Ruckus. Does anyone know if other manufacturer's products with multiple > > antennas do any kind of beam forming, or do the offerings of other > > manufacturers with multiple antennas merely use one antenna or the other > at > > any given instant. I understand that Ruckus' product is highly > specialized > > in the antenna/beam forming aspect and has a very involved antenna array > and > > control system, but still the other manufacturer's products with only two > > simple rubber duckies could still do some pattern shaping if the phasing > of > > the two antennas is varied, not as effectively as the Ruckus products of > > course, but it would offer some improvement as far as gain and especially > > multipath/interference rejection. > > > > Greg > > > > > > > -------------------------------------------------------------------------------- > > WISPA Wants You! Join today! > > http://signup.wispa.org/ > > > -------------------------------------------------------------------------------- > > > > WISPA Wireless List: [email protected] > > > > Subscribe/Unsubscribe: > > http://lists.wispa.org/mailman/listinfo/wireless > > > > Archives: http://lists.wispa.org/pipermail/wireless/ > > > > > > -- > Thanks, > Brough > > Skype: brough Mobile: +1 617 285 0433 > http://blogs.broughtunrer.com > > > > > -------------------------------------------------------------------------------- > WISPA Wants You! Join today! > http://signup.wispa.org/ > > -------------------------------------------------------------------------------- > > WISPA Wireless List: [email protected] > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ > -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
