Re: [WISPA] chipset vs standard based beam forming?
A good primer on 802.11n. Beamfroring starts at page 6. Brough Turner wrote: > As Mike points out, beamforming is an optional part of the 802.11n > standard and there is at least some silicon support for this option > emerging (more on that in a moment). The confusion arises because > there are several different things which are legitimately called > beamforming. > > The simplest is a switched beamformer in which there are multiple > directional antenna elements and the radio is connected to the > appropriate elements as needed. This is what Ruckus Wireless does > today. They have 12 or more fixed elements and on a frame-by-frame > basis they decide which two of those elements to connect to the two > terminals on the Atheros (2x2 MIMO) Wi-Fi chip. A bunch of people > have patents here, but the ideas are very old so the patents may not > be very valuable. > > Next is phased array beamformers. Here there are multiple simple > antenna elements typically equally spaced in an array. Phase delays > are introduced so, via constructive and destructive interference, you > end up with a beam. Then that beam is steered by varying the phase > delays. This is also well established technologies that the military > have been using for (many) decades. > > Finally, in MIMO systems, maximal-ratio-combining (MRC) is doing > receive beamforming in as much as the computation is equivalent to > placing the maximum receive lobe as close to the desired signal while > placing nulls as close as possible to the primary interferers. > > While the widespead 2x2 MIMO chips are primarily used for horizontal > and vertical polarization, 3x3 and 4x4 MIMO chips are emerging. With > 4x4 we can expect to see transmit beamforming via phasing and receive > beamforming via MRC. Indeed, two silicon startups, Quantenna > Communications in California and Celeno Wireless in Israel, have > announced Wi-Fi chips that support 4x4 MIMO with transmit > beamforming. The Quantenna chip is used in the Netgear WNHDB3004. > > The 802.11n standard specifies how the needed information is passed, > so the computations that Quantenna and Celeno (and others in the > future) do can be carried out when devices from different vendors > interoperate. > Thanks, > Brough > > Skype: brough Mobile: +1 617 285 0433 > http://blogs.broughturner.com > > > On 10/26/10 12:37 PM, Mike Hammett wrote: >> http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4558648 >> >> "In the IEEE 802.11n draft standard, beamforming is adopted as an >> optional feature to improve signal reception and simplify receiver design." >> >> Beamforming is available in 802.11N, though I don't know of any products >> using that standard. >> >> - >> Mike Hammett >> Intelligent Computing Solutions >> http://www.ics-il.com >> >> >> >> On 10/25/2010 5:15 PM, Faisal Imtiaz wrote: >> >>> Rogelio, >>> >>> Please don't take this the wrong way. You are trying to understand a >>> very complex 'patented' technology via a very simplistic understanding. >>> >>> Beam forming is a very complex (lots of analytical analysis done on a >>> real time basis) technology, there are a number of Masters& PHD Thesis >>> papers on this topic that you can find by Googling. >>> >>> There is no 'chipset' for it Each of the folks you mention utilize >>> 'internally developed' patented techniques of applying the 'Beam >>> Forming" concept. so there is no 'standard' the chipset are simple >>> transmitters and signal processors (math units..) >>> >>> The beam forming technology works in both direction (sending& >>> receiving). There is no such thing as a 'omni' beam forming >>> antenna. The antenna pattern is dynamically changed to focus / lock on >>> to the signal of the CPE that the AP is talking to. >>> >>> Plus, there is NO 'Beam Forming" Standard...and don't expect one in the >>> future. since it is more of a 'type of antenna design' and not a >>> 'defined formula'. >>> >>> Regards. >>> >>> Faisal Imtiaz >>> Snappy Internet& Telecom >>> >>> On 10/25/2010 5:54 PM, Rogelio wrote: >>> I see lots of discussion about the new 802.11n standard supporting beam forming, and I'm trying to wade through the chipset ones (e.g. Ruckus, Extricom, Meru, etc) and other solutions that claim to be more standards based. > From what I gather from the marketing literature, the various vendor > solutions direct the signal "more efficiently" towards specific targets (focusing beam in certain direction, monitoring interference, "interference nulling", etc), but that seems to have limited effectiveness when it comes to receiving transmitted packets from the client end (resulting in slow uplink?). In some of these cases, the receive antennas are just an omni antenna. (802.11 is not a timing based protocol, so I don't see how beamforming benefits on the receive
Re: [WISPA] chipset vs standard based beam forming?
As Mike points out, beamforming is an optional part of the 802.11n standard and there is at least some silicon support for this option emerging (more on that in a moment). The confusion arises because there are several different things which are legitimately called beamforming. The simplest is a switched beamformer in which there are multiple directional antenna elements and the radio is connected to the appropriate elements as needed. This is what Ruckus Wireless does today. They have 12 or more fixed elements and on a frame-by-frame basis they decide which two of those elements to connect to the two terminals on the Atheros (2x2 MIMO) Wi-Fi chip. A bunch of people have patents here, but the ideas are very old so the patents may not be very valuable. Next is phased array beamformers. Here there are multiple simple antenna elements typically equally spaced in an array. Phase delays are introduced so, via constructive and destructive interference, you end up with a beam. Then that beam is steered by varying the phase delays. This is also well established technologies that the military have been using for (many) decades. Finally, in MIMO systems, maximal-ratio-combining (MRC) is doing receive beamforming in as much as the computation is equivalent to placing the maximum receive lobe as close to the desired signal while placing nulls as close as possible to the primary interferers. While the widespead 2x2 MIMO chips are primarily used for horizontal and vertical polarization, 3x3 and 4x4 MIMO chips are emerging. With 4x4 we can expect to see transmit beamforming via phasing and receive beamforming via MRC. Indeed, two silicon startups, Quantenna Communications in California and Celeno Wireless in Israel, have announced Wi-Fi chips that support 4x4 MIMO with transmit beamforming. The Quantenna chip is used in the Netgear WNHDB3004. The 802.11n standard specifies how the needed information is passed, so the computations that Quantenna and Celeno (and others in the future) do can be carried out when devices from different vendors interoperate. Thanks, Brough Skype: brough Mobile: +1 617 285 0433 http://blogs.broughturner.com On 10/26/10 12:37 PM, Mike Hammett wrote: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4558648 "In the IEEE 802.11n draft standard, beamforming is adopted as an optional feature to improve signal reception and simplify receiver design." Beamforming is available in 802.11N, though I don't know of any products using that standard. - Mike Hammett Intelligent Computing Solutions http://www.ics-il.com On 10/25/2010 5:15 PM, Faisal Imtiaz wrote: Rogelio, Please don't take this the wrong way. You are trying to understand a very complex 'patented' technology via a very simplistic understanding. Beam forming is a very complex (lots of analytical analysis done on a real time basis) technology, there are a number of Masters& PHD Thesis papers on this topic that you can find by Googling. There is no 'chipset' for it Each of the folks you mention utilize 'internally developed' patented techniques of applying the 'Beam Forming" concept. so there is no 'standard' the chipset are simple transmitters and signal processors (math units..) The beam forming technology works in both direction (sending& receiving). There is no such thing as a 'omni' beam forming antenna. The antenna pattern is dynamically changed to focus / lock on to the signal of the CPE that the AP is talking to. Plus, there is NO 'Beam Forming" Standard...and don't expect one in the future. since it is more of a 'type of antenna design' and not a 'defined formula'. Regards. Faisal Imtiaz Snappy Internet& Telecom On 10/25/2010 5:54 PM, Rogelio wrote: I see lots of discussion about the new 802.11n standard supporting beam forming, and I'm trying to wade through the chipset ones (e.g. Ruckus, Extricom, Meru, etc) and other solutions that claim to be more standards based. From what I gather from the marketing literature, the various vendor solutions direct the signal "more efficiently" towards specific targets (focusing beam in certain direction, monitoring interference, "interference nulling", etc), but that seems to have limited effectiveness when it comes to receiving transmitted packets from the client end (resulting in slow uplink?). In some of these cases, the receive antennas are just an omni antenna. (802.11 is not a timing based protocol, so I don't see how beamforming benefits on the receive side will ever happen) So is the best that we can hope for with beam forming is faster download but the same old upload? How will the standard (once baked in more vendor gear) do things differently? WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireles
Re: [WISPA] chipset vs standard based beam forming?
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4558648 "In the IEEE 802.11n draft standard, beamforming is adopted as an optional feature to improve signal reception and simplify receiver design." Beamforming is available in 802.11N, though I don't know of any products using that standard. - Mike Hammett Intelligent Computing Solutions http://www.ics-il.com On 10/25/2010 5:15 PM, Faisal Imtiaz wrote: > Rogelio, > > Please don't take this the wrong way. You are trying to understand a > very complex 'patented' technology via a very simplistic understanding. > > Beam forming is a very complex (lots of analytical analysis done on a > real time basis) technology, there are a number of Masters& PHD Thesis > papers on this topic that you can find by Googling. > > There is no 'chipset' for it Each of the folks you mention utilize > 'internally developed' patented techniques of applying the 'Beam > Forming" concept. so there is no 'standard' the chipset are simple > transmitters and signal processors (math units..) > > The beam forming technology works in both direction (sending& > receiving). There is no such thing as a 'omni' beam forming > antenna. The antenna pattern is dynamically changed to focus / lock on > to the signal of the CPE that the AP is talking to. > > Plus, there is NO 'Beam Forming" Standard...and don't expect one in the > future. since it is more of a 'type of antenna design' and not a > 'defined formula'. > > Regards. > > Faisal Imtiaz > Snappy Internet& Telecom > > On 10/25/2010 5:54 PM, Rogelio wrote: >> I see lots of discussion about the new 802.11n standard supporting >> beam forming, and I'm trying to wade through the chipset ones (e.g. >> Ruckus, Extricom, Meru, etc) and other solutions that claim to be more >> standards based. >> >>> From what I gather from the marketing literature, the various vendor >> solutions direct the signal "more efficiently" towards specific >> targets (focusing beam in certain direction, monitoring interference, >> "interference nulling", etc), but that seems to have limited >> effectiveness when it comes to receiving transmitted packets from the >> client end (resulting in slow uplink?). In some of these cases, the >> receive antennas are just an omni antenna. (802.11 is not a timing >> based protocol, so I don't see how beamforming benefits on the receive >> side will ever happen) >> >> So is the best that we can hope for with beam forming is faster >> download but the same old upload? How will the standard (once baked >> in more vendor gear) do things differently? >> >> >> >> WISPA Wants You! Join today! >> http://signup.wispa.org/ >> >> >> WISPA Wireless List: wireless@wispa.org >> >> 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: wireless@wispa.org > > 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] chipset vs standard based beam forming?
This reminds me of another question I have: Why dont I get synchronous speeds? On a rare occasion, I do, but not normally. LOL, once in a while, I get better uploads than downloads and cant explain that either! On Mon, Oct 25, 2010 at 6:15 PM, Faisal Imtiaz wrote: > Rogelio, > > Please don't take this the wrong way. You are trying to understand a > very complex 'patented' technology via a very simplistic understanding. > > Beam forming is a very complex (lots of analytical analysis done on a > real time basis) technology, there are a number of Masters & PHD Thesis > papers on this topic that you can find by Googling. > > There is no 'chipset' for it Each of the folks you mention utilize > 'internally developed' patented techniques of applying the 'Beam > Forming" concept. so there is no 'standard' the chipset are simple > transmitters and signal processors (math units..) > > The beam forming technology works in both direction (sending & > receiving). There is no such thing as a 'omni' beam forming > antenna. The antenna pattern is dynamically changed to focus / lock on > to the signal of the CPE that the AP is talking to. > > Plus, there is NO 'Beam Forming" Standard...and don't expect one in the > future. since it is more of a 'type of antenna design' and not a > 'defined formula'. > > Regards. > > Faisal Imtiaz > Snappy Internet & Telecom > > On 10/25/2010 5:54 PM, Rogelio wrote: > > I see lots of discussion about the new 802.11n standard supporting > > beam forming, and I'm trying to wade through the chipset ones (e.g. > > Ruckus, Extricom, Meru, etc) and other solutions that claim to be more > > standards based. > > > > > From what I gather from the marketing literature, the various vendor > > solutions direct the signal "more efficiently" towards specific > > targets (focusing beam in certain direction, monitoring interference, > > "interference nulling", etc), but that seems to have limited > > effectiveness when it comes to receiving transmitted packets from the > > client end (resulting in slow uplink?). In some of these cases, the > > receive antennas are just an omni antenna. (802.11 is not a timing > > based protocol, so I don't see how beamforming benefits on the receive > > side will ever happen) > > > > So is the best that we can hope for with beam forming is faster > > download but the same old upload? How will the standard (once baked > > in more vendor gear) do things differently? > > > > > > > > > WISPA Wants You! Join today! > > http://signup.wispa.org/ > > > > > > > WISPA Wireless List: wireless@wispa.org > > > > 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: wireless@wispa.org > > 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] chipset vs standard based beam forming?
> "interference nulling", etc), but that seems to have limited > effectiveness when it comes to receiving transmitted packets from the > client end (resulting in slow uplink?). Multi-antenna systems like the ones doing beamforming can provide MRC (Maximal-Ratio Combining), which does improve the receive SNR. It's not beamforming per se but having an antenna array with proper wavelength fractions separation improves MRC performance. > In some of these cases, the > receive antennas are just an omni antenna. (802.11 is not a timing > based protocol, so I don't see how beamforming benefits on the receive > side will ever happen) 802.11 systems with TDMA-like protocols (AirMax, Nstreme v2) may change that. > So is the best that we can hope for with beam forming is faster > download but the same old upload? How will the standard (once baked > in more vendor gear) do things differently? My personal experience with 802.16e 4- and 8-antenna systems is the opposite of that, with upload coverage and quality (not speed) being improved the most. Download speeds are better but cell capacity is usually not an issue on the first years of a continuos coverage system; cell radius impacts directly on upfront CAPEX. Rubens WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] chipset vs standard based beam forming?
Rogelio, Please don't take this the wrong way. You are trying to understand a very complex 'patented' technology via a very simplistic understanding. Beam forming is a very complex (lots of analytical analysis done on a real time basis) technology, there are a number of Masters & PHD Thesis papers on this topic that you can find by Googling. There is no 'chipset' for it Each of the folks you mention utilize 'internally developed' patented techniques of applying the 'Beam Forming" concept. so there is no 'standard' the chipset are simple transmitters and signal processors (math units..) The beam forming technology works in both direction (sending & receiving). There is no such thing as a 'omni' beam forming antenna. The antenna pattern is dynamically changed to focus / lock on to the signal of the CPE that the AP is talking to. Plus, there is NO 'Beam Forming" Standard...and don't expect one in the future. since it is more of a 'type of antenna design' and not a 'defined formula'. Regards. Faisal Imtiaz Snappy Internet & Telecom On 10/25/2010 5:54 PM, Rogelio wrote: > I see lots of discussion about the new 802.11n standard supporting > beam forming, and I'm trying to wade through the chipset ones (e.g. > Ruckus, Extricom, Meru, etc) and other solutions that claim to be more > standards based. > > > From what I gather from the marketing literature, the various vendor > solutions direct the signal "more efficiently" towards specific > targets (focusing beam in certain direction, monitoring interference, > "interference nulling", etc), but that seems to have limited > effectiveness when it comes to receiving transmitted packets from the > client end (resulting in slow uplink?). In some of these cases, the > receive antennas are just an omni antenna. (802.11 is not a timing > based protocol, so I don't see how beamforming benefits on the receive > side will ever happen) > > So is the best that we can hope for with beam forming is faster > download but the same old upload? How will the standard (once baked > in more vendor gear) do things differently? > > > > WISPA Wants You! Join today! > http://signup.wispa.org/ > > > WISPA Wireless List: wireless@wispa.org > > 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
[WISPA] chipset vs standard based beam forming?
I see lots of discussion about the new 802.11n standard supporting beam forming, and I'm trying to wade through the chipset ones (e.g. Ruckus, Extricom, Meru, etc) and other solutions that claim to be more standards based. >From what I gather from the marketing literature, the various vendor solutions direct the signal "more efficiently" towards specific targets (focusing beam in certain direction, monitoring interference, "interference nulling", etc), but that seems to have limited effectiveness when it comes to receiving transmitted packets from the client end (resulting in slow uplink?). In some of these cases, the receive antennas are just an omni antenna. (802.11 is not a timing based protocol, so I don't see how beamforming benefits on the receive side will ever happen) So is the best that we can hope for with beam forming is faster download but the same old upload? How will the standard (once baked in more vendor gear) do things differently? WISPA Wants You! Join today! http://signup.wispa.org/ WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
