Looking Beyond the Room

For those of you that don’t follow Devin AkinJared Griffith or Jeanette Lee on Twitter… let me give you an update. 

Effectively it is being argued that Ruckus technology (adaptive antennas, ChannelFly etc) has no effect on performance in a classroom environment because all of the 30+ iPad devices in the classroom are limited by their downstream throughput which is about 25Mbps. In Aerohive’s “Need for Speed” blog they state that these iPad consume about 80% of the airtime even though they are moving at relatively slow speeds by today’s standards. I haven’t personally tested this but I believe these numbers. 

Now, my response.

First off, I work for Ruckus and this blog is Ruckus centric. I’ll try to not make a habit of it. Promise.  

One of the things that I have stressed with all of my Wi-Fi students over the years is to look at a Wi-Fi network as a whole organic structure. Understanding the protocols and RF between an AP and a client are essential but the next step is to understand how each Wi-Fi device (STA or AP) effects each other. We don’t live in a world with one AP. 

High Density Myth #1: Adaptive Antennas (BeamFlex) doesn’t help the throughput of an iPad. 

True (yes, you read it right). If you test one iPad with one AP within 10 feet of each other in a clean environment, you’ll probably get similar results from most vendors including Linksys and Netgear. Unfortunately for those vendors, that situation only exists in poorly thought out tests.

BeamFlex is an adaptive antenna technology that customizes signals in both direction and polarity to optimize the signal for the client device. That is what BeamFlex is most known for anyway. However, one of the significant but unsung benefits of adaptive antennas is the reduction of co-channel (AP to AP) interference.

Imagine that you install one AP per classroom like is recommended by most vendors. Now you have a multitude of APs within close proximity of each other. If they follow their standard channel plan of 1,6,11 then you will have significant co-channel interference because you bought too many APs. And, don’t give me that crap about reducing transmit power for “smaller cells”. That only works so so and if you reduce the transmit power enough to make a real difference then you reduce the data rate to the client devices creating a new host of problems. 

Signal control while maintaining appropriate transmit power reduces co-channel interference while keeping data rates high. 

High Density Myth #2: Channel selection is simple

The “standard” channel plan is to use 1,6 and 11 and change channels when some arbitrary measurements hit a pre-determined threshold. Ruckus invented a technology called ChannelFly that works off of a very simple measurement. Capacity. Each AP selects the channel that gives it the best possible throughput and network capacity. It’s secret sauce how this happens but it really makes a difference. Don’t trust me, try it in real life (I hate lab environments). 

High Density Myth #3: More clients equals more APs

One of the most common and significant mistakes in Wi-Fi network design is installing too many APs. Ask any independent Wi-Fi consultant and they’ll tell you that they have, at some point in their career, turned APs off in order to improve the network. Is one AP per classroom appropriate? Only in limited cases. Many factors must be present before I recommend one AP per classroom. Many vendors arbitrarily and consistently recommend this and I do not agree with this practice. 

My Invitation

More than likely you will test each vendor’s Wi-Fi gear before you buy. I highly encourage it. However, here is what I ask of you. If you want to test one AP in a classroom that is fine but if you want to see real results, test in as real of an environment as you can. Install 6+ APs, stress them all and observe the overall network performance. 

Each vendor puts focus on solving a different problem. Some problems are real and some aren’t. Ruckus is the Ferrari/Lamborghini/McLaren F1/Bugatti/Ducati of the Wi-Fi world because that is where we put our focus. Ruckus has more Wi-Fi engineers than Aerohive, Xirrus, Meru and Meraki combined. Ok, I made that up (blogs do that) but I bet I’m not far off. 🙂


37 thoughts on “Looking Beyond the Room

  1. Devin Akin says:

    Hey bro, thanks for your write-up on this topic. I’d like to address your points in order if I might.

    Myth #1:

    Absolutely I’m going to give you that “crap” about reducing transmit power for smaller cells. iPads are generally only transmitting at 10-20mW when operating on battery power, and we all understand balanced links. Within a classroom, there’s absolutely no reason for an AP to be shouting while iPads are whispering. 10-20mW within the four walls of a standard classroom is high enough to maintain a 65Mbps connection for all iPads – their maximum transmission rate. Therefore, AP-to-AP interference avoidance isn’t helping much here for 2.4GHz, and practically nothing for 5GHz.

    Myth #2:

    I don’t know that any of us ever made any assertions against ChannelFly in regards to this conversation, but I will say that Syracuse University’s study of a 4-channel plan (readily available) is a pretty strong argument against ChannelFly. Further, not all clients (iPads?) support CSAs, and that could be pretty disruptive in a video-heavy environment.

    Myth #3:

    Completely agree with you that there can be too many APs in a network. However, one-AP-per-classroom is typically the right design for iPads given the amount of airtime/throughput available on a channel when using a homogeneous population of 1SS-capable clients, the applications being used in the classroom, and the client density within a classroom (up to 40 max typical for public schools). Aerohive has a couple of thousand schools who can testify, and I know Ruckus does as well. We have many schools with 1-AP-per-classroom and many schools with 1-AP-per-2-classrooms. It all depends on client and application types.

    With all iPads (1×1:1), you can get ~25Mbps aggregate per 20MHz channel. With all 2×2:2 MacBooks, you can easily get more like 90-120Mbps aggregate per 20MHz channel (depending on 2.4GHz or 5GHz). That’s a whopping difference of available throughput per channel.

    The point we were all trying to make on Twitter is that classrooms should be designed based on your client population capabilities & density and application requirements. With a 1-AP-per-classroom, this often means that with the proper features, such as intelligent band steering, airtime fairness, and a good QoS engine, a 2×2:2 AP will serve a room full (~40) of iPads extremely well. It’s also important to have control of your applications (e.g. your video server should be able to serve video at a constant bit rate).

    Hope this helps.

  2. gthill says:

    Hey Devin – Thanks for the quick and thorough response. My response to your response (this could get confusing) 🙂 is below.

    Myth #1 – First, a balanced link is a myth itself. More to come on that in a separate blog / paper. Second, I do agree that power reduction is ok but it is far from a silver bullet that eliminates co-channel interference.

    Myth #2 – All Apple devices support CSAs as do a surprising number of 2.4 GHz devices. We’ll have to disagree with different channel plans for now but our engineers and many of our customers in high-density environments have observed significant (30+%) capacity increase from ChannelFly.

    Myth #3 – It looked to me like the point you were trying to make on Twitter was that Ruckus tech didn’t help in the classroom. I have no problem with that; we work for different vendors out there battling for the same business. Just as I expect that when I write about controllers I fully expect a response from you. 🙂


  3. Hi GT,
    *Disclaimer – I work for Aerohive now*

    Myth #1 – I have two problems with the whole “adaptive antennas reduce interference” claim (aka interference avoidance). First, when adaptive antennas increase signal gain toward a specific client then it stands to reason that any Wi-Fi cell in that same direction is likewise experience higher signal gain and would result in increased interference. Sure, AAs reduce interference in one direction but increase it in another. So I don’t buy that argument. Overall, I do like the Ruckus AAs. I’m not bashing on the technology, but I think that claim is at least partially bunk 😛

    Otherwise, I agree with most of your points.

    We absolutely need to design and test in real-world environments. Co-channel and adjacent channel interference is the biggest problem in Wi-Fi, and is why experienced professionals performing site surveys and designing a network properly are so desperately valuable. I put more stock in proper Wi-Fi network requirements gathering, planning, design, site survey, verification, installation, re-verification, user acceptance testing, etc. than any Wi-Fi feature from any Wi-Fi vendor. AAs are great technology, but it doesn’t solve CCI / ACI problems. Let’s focus on proper “real-world design” instead.

    Myth #2 – Channel selection is not simple (agree there) but I have seen many alternate channel plans result in significantly worse performance than 1, 6, 11. As I understand ChannelFly, it works by measuring real-world throughput and selecting the best channel. But it can’t simultaneously do this on all channels, so effectively it only has a point-in-time measurement. Once it’s operating a specific channel with clients attached, how does it continually test/measure other channels to know if a better option is available? Call me a skeptic, but ChannelFly would have to be proven to me before I believe it. I’ve never tested it, and maybe it does work, but I won’t abandon 1, 6, 11 until proven otherwise.

    Myth #3 – 100% agree. I think that Gartner article on “300% more Wi-Fi” is scaring organizations into buying too much Wi-Fi 🙂 Seriously, before I joined Aerohive, I was a network architect at a large organization and had numerous discussions (probably a dozen or more) about that very article and the tone was “oh my god, what should we do?” I had to explain how our environment was designed and what we needed as an organization based on our needs, not what some analyst stated in a blanket market statement. Too many APs causes performance issues. Although “network-rightsizing” was an overused term a few years ago for wired to wireless as the primary network (e.g. switch port reductions), it does accurately depict the need for the proper amount of wireless radios to serve the client demand.

    Andrew vonNagy

    • gthill says:

      #1 – Don’t think of adaptive antennas as just devices that increase signal, think of them as devices that control the signal. Think of it this way; if an AP could shoot signal like a bullet (or a wire) would that reduce the interference? Yes it would because it would affect fewer devices. We can’t fire it like a bullet (yet) but it does reduce interference.

      Another example is that of directional antennas. We always used them indoors for added gain and / or reduce interference in other directions. Adaptive antennas just do this automatically.

      #2 – ChannelFly is one of those technologies that we just can’t seem to convince anyone of until they test it for themselves. Worst case scenario for ChannelFly is that it will eliminate the bottom 30% of bad channels that most vendors will spend time on because they look at information that doesn’t always translate into a good or bad communication channel.

      #3 – We agree so how can I argue that? 🙂


      • #1 – Yes, it is similar to a semi-directional or directional antenna. But it is NOT the same. Unlike directional antennas, AAs only work in one direction (downlink) not both (like directional antennas).

        Directional antennas could also increase interference in the direction they are pointed, but this is much easier to plan for in a multi-cell network design. AAs could increase interference for adjacent cells in all directions. I’d say this complicates network design, especially in high density environments where multiple APs must interact as a system.

        My view of AAs are that they are great for improving rate-over-range for a coverage oriented network. But for a network designed for high capacity which already plans for clients connected with a high SINR, they can’t really help. Pro’s and Con’s.

        Good discussion 😉


      • gthill says:

        I’m having a bit of trouble understanding a few comments… one from you (Andrew) and one from Twitter (Kevin).

        Rate over range is an improvement and I’ll take it. But, I’m not sure how else I can put it… how is controlling the signal shape and direction NOT help with co-channel interference?

        And… uplink vs. downlink. Seems like we keep getting hung up on that. Ruckus puts a lot of emphasis on receive sensitivity. For example, PD-MRC can improve uplink reliability significantly. Even if Ruckus didn’t positively effect uplink, you still get advantages on the downlink which represents what… 80% of the traffic in edu?


      • GT,
        I’d like to leave a drawing within this comment, but I’ve researched it and have not found a way to do that.

        So, in lieu, I’ve posted my own fantabulous drawing of what I’m getting about simultaneous interference rejection and interference creation (in different directions) on my website:

        To be clear, I’m saying AAs help in one respect while hurting in another respect. Double-edged sword.

        Hopefully this makes sense!


      • gthill says:

        I understand the point you are making but you are assuming that we are going for extra gain in all cases which isn’t true. If all we wanted was extra gain we’d put some big ass omnis on there and call it awesome.

        Imagine that the coverage area stays the same except that every transmission is sent directionally. It doesn’t completely eliminate co-channel interference but it sure does reduce it.


      • In what cases are you NOT attempting to achieve additional gain to the client device? I’d really like to know. I don’t see how you can say AAs improve SINR to the client device, then say that the same signal then doesn’t affect other stations in the signal path.

        I’m just not getting your argument. I think you’re being too “vendor koolaid” without being realistic about a small potential downside to AAs.


      • gthill says:

        Man… I’m about the farthest thing from vendor kook-aid for a guy that works for a vendor. I’ve actually gotten in trouble from Ruckus e-staff because of my competitive objectivity.

        The original argument that Devin was making was that AAs don’t help when you have an AP in the classroom and that room is all you are trying to cover. My point is that while the extra signal may not help, the control of the signal will.

        I think you are missing a point as well. When you concentrate the signal you will affect fewer devices (co-channel) even if you are adding gain by doing it.

        To make this make sense you have to think in extremes. If a signal could be laser like, would you agree that it would “hit” less devices even if it was much stronger than the omni light bulb? Of course AAs can’t concentrate to that level but the reduction in beamwidth does help.

        I know you discounted the analogy to a directional antenna because of uplink vs. downlink (which is another discussion) but the principal still stands.

        Anytime there is a super high density situation one of the ways to help is to use antennas the lower the beamwidth. AAs do this packet by packet instead of static but the result is the same.


      • Devin Akin says:

        That’s it. I’m adopting that term: kook-aid. 😀 GT, we love you man. We all get ripped for being vendor-centric even though we love the technology much more than the vendor spew. It’s our job to champion the technology that our company has, and we do so with vigor. No vendor has it “all figured out” or has a “perfect” solution, so in the end, it’s about making sure the solution that you sell meets your customer’s needs. We all do the best we can. That’s where integrity comes in, right?

        I read your counter-counter-counter-counter…counter-counter arguments above, and what I came away with was that IF IF IF that was true, then you’d be causing downlink hidden node whereby some client devices in the classroom wouldn’t hear the transmissions of the AP, and therefore you would get unnecessary collisions. Wanna concede that?

        With an omni antenna in a classroom (very close quarters), in my technical opinion, there is simply no need for an AA because all client devices are at the maximum data rate all the time. Per an amazing Atheros design engineer I once spoke with, TxBF was only designed for the mid range use case, as at close and long range it’s useless. Same applies to AA within four walls, disregarding other classrooms. For uplink Rx, Ruckus is using its omni antennas, right? You can concede anytime now… 😛

        If it’s 1 AP per 2 or 3 classrooms, some of your points about AA are solid (and conceded), but then you can’t argue the iPad density/speed issue due to limited airtime/throughput due to 1SS capability of iPads. Just sayin’.



      • gthill says:


        In some ways this is like arguing about the economy because there are so many factors involved. Neither side can prove their theory without actually trying it. Which is what we (Ruckus) always want. I believe that in realistic (non-lab) environments Ruckus tech will demonstrate significant improvements over conventional methods. Maybe a bake-off is in store? 🙂


        Hugs are cool but in a few blogs you may not want to hug me. 🙂

      • Devin Akin says:

        Are you suggesting that you can get a 65Mbps capable iPad to go faster than we can?…or maybe 40 65Mbps capable iPads to go faster than we can with 1Mbps downlink video? That’s just silly. As long as Ruckus can support bi-directional band steering, airtime fairness, and a CBR-capable video source is used, it would always essentially be a tie because of the iPad being the bottleneck. Both of our systems are capable of a big multiple of what that room of iPads is capable of in aggregate. Come on man…keep it real….real-world that is. 😉

        I think you NEED a hug. Maybe two.


      • gthill says:

        What I am saying (not suggesting 🙂 ) is that cumulative network throughput and capacity will be higher with Ruckus than any vendor out there. What is real is 30+ devices in each room with classrooms stacked on every side of each other. That, in my opinion, is real world.


    • Hi GT,
      I think we all have a bit of kool-aid in us, just make sure it’s not Tang 🙂 That stuff is nasty! I think people of our type always get slapped on the hand from time to time because we care about the technology first and foremost, and vendor positioning takes a backseat. It’s who we are.

      Back to the technical discussion… I should preface this with “2.4GHz frequency capacity” is the problem here. In the 5GHz band where the channel plan can reduce co-channel interference to much lower levels, I don’t think the additional gain from AAs would cause much more interference than omnis.

      I’m in agreement with you that focusing the signal reduces co-channel interference in other directions. No argument there. All that I’m saying is that there is a flipside to that which is increased co-channel interference in the direction of the client and of subsequent Wi-Fi cells in that direction.

      I would also argue that the “control” of the signal may help in some circumstances and hurt in others. It depends on the physical client distribution around the AP and where neighboring APs are in relation and the facility characteristics (e.g. construction material and signal attenuation).

      In my opinion, omnis are more predictable and the coverage overlap and co-channel interference can be planned for in the network design. Adaptive antennas are less predictable and harder to design the network to minimize co-channel interference because the antenna could focus the signal in any direction based on client location. If the client locations can’t be controlled then the only two real options in my mind to keep co-channel interference at comparable low-levels to an omni are 1) reduce Tx power to compensate for beamforming, but that negates the signal gain benefit of adaptive antennas in the first place, or 2) push APs farther apart to increase FSPL which is fine in a coverage oriented network but not in a high density network where more capacity is needed.

      Ultimately, my opinion is that AAs are of benefit in the 2.4GHz band in “coverage-oriented” networks but provide significantly less value in high-density Wi-Fi environments where APs are closer together and the network is designed to provide a high quality signal strength and SNR to clients anyways, which is becoming increasingly common.

      Can we just agree that devices should use 5GHz where greater spectral capacity exists today. And that we probably need more unlicensed spectrum in anticipation of the day several years down the road where 5GHz becomes more saturated with wider channels and more devices. I’ve heard rumors of more unlicensed spectrum talks by the FCC; I hope it happens.

      Great discussion!

  4. Devin Akin says:

    Hey bro. Good stuff.

    I guess you could argue that balanced link is a myth from various standpoints, but all-in-all, it’s about not transmitting with more power than is necessary so as not to cause more interference than is necessary, right? I know your “comeback” will be about transmitting in the right “place” via directional transmission using an adaptive antenna, but that has no specific advantage within the four walls of a classroom — if you isolate the scenario from the rest of the network of course. Your previous point about AP-to-AP interference is taken, though a good design and RRM matters much. Client-side interference is much more severe than AP-side interference en-total anyway, and in fact, it’s very likely that clients from one classroom could more easily affect clients from another classroom more easily than APs from one classroom could affect APs from another classroom (due to physical proximity) IF good RRM is in use within the infrastructure.

    I think ChannelFly may have its uses, and I won’t argue that point. I think also that there may be a trade-off of added capacity versus application disruption depending on client-side CSA support. It might be worth it, it might not. It’s for the customer to decide based on their specific variables.

    The points I was trying to make on Twitter were that an adaptive array adds zilch in a 1-AP-per-classroom-with-all-iPads scenario for a variety of reasons, such as all iPads being only 65Mbps capable (1SS, 20MHz), all iPads being at 65Mbps data rate 100% of the time regardless of whether you use omni antennas or an adaptive array (or how you hold your iPad), and throughput is a constraint of the iPad radio (not the AP). The most important features then, for this scenario, seem to be intelligent band steering, airtime fairness, and intelligent QoS.

    Hope this clarifies. I wasn’t going down the controller route (for once). 🙂 That’s a whole different argument.


  5. A sports car needs great tires, suspension, a good transmission system and powerful engine (broadly speaking). In the car race every team has some advantage in the above mentioned specific. But at the end of the day it is the driver that wins or looses the race.

    To show a point here is an interesting video about an experienced driver trying to drive a formula 1 car: http://www.youtube.com/watch?v=EGUZJVY-sHo

    This guy has driven everything, from Ferraris to 1000 HP Bugatti beasts. And when tasked controlling an F1 car… well, just look at the video. Again, this was not an ordinary, everyday car owner.

    Now bringing this to WiFi. I can confidently say that I can design for HD with EVERY enterprise level WiFi vendor. No exceptions (just don’t sell me prosumer products as an enterprise gear ;)). Some sport great tires, and some great engine and the driver has use the advantages and compensate for disadvantages.

    Sadly there are lot of experienced drivers (network specialist) and so few WiFi specialist (F1 drivers).

    Back to schools.

    1AP per classroom works great if the environment permits for that. From the standpoint of overall capacity, 2 APs (1 per classroom) will trump 1 AP per classroom, again if designed correctly. A lot of schools have brick walls or concrete walls where RF cell separation is easier to achieve. If the school has drywalls then maybe picocell type of deployment (under the floor settings) may be achievable.

    On the other-hand, if the application diversity is not high, where robust QoS engine, dynamic SLAs engines, etc., are required, Ruckus can indeed provide ample of performance with considerably less APs.

    And just to nick-pick the engineer count reference. Cisco has support teams for single fortune 50 company bigger than Ruckus engineer team. Doesn’t mean a thing. Ruckus still kicks ass and so does Aerohive, Meraki, Xirrus and Meru, all within their own rights.

    My 2 cents.

    Gregor Vucajnk

  6. I read Andrews’ comment of AA being downlink only as the client will not reciprocate in the same fashion as the AA, instead, spreading its’ joy 360 degrees around. It is a similar concept as shining a flashlight on a lightbulb

  7. Sami Susiaho says:

    I love the banter, really good stuff, thank you GT, Devin and Andrew.
    IMHO, you guys might stress the importance of the AP a bit too much though. The biggest contributors to the deployment in the real world are the client devices and the environment they operate in. The installation and RF planning being on the second tier and the AP infra itself a distant third.
    Changing an AP to another is quite easy for a hotspot operator such as us, the results are immediately shown. I would heartily recommend some bold, real-world testing for anyone who is trying to decide what kit is best for their deployment.
    The proof is in the pudding as they say around here.

    • Devin Akin says:

      Hi Sami,

      This discussion centered around iPads in the classroom, which is a homogenous client population within a fixed distance perimeter. Being an operator, you are focused mostly on heterogeneous client populations at varying distances from the AP. The crux of the discussion was around airtime utilization, throughput limitations due to client capabilities, and important feature sets. The differentials between a hotspot operator’s typical environment and that of a typical school are dramatic…nearly opposite in fact. We weren’t discussing generalities of deployment, but rather one specific deployment scenario only in this thread.

      Hope this helps clarify!


  8. Thanks GT, helpful as ever. You’re always going to get differing opinions, especially from other vendors keen to argue against tech such as AA and Channel Fly that they have no answer for. The fact is, as the largest Ruckus disty in EMEA, we see plenty of real-world deployments where competitive systems, including those from your two esteemed commentators Andrew and Devin, are out performed by Ruckus. We have hundreds of resellers with experience of all the top enterprise WLAN vendors, most decent resellers carry at least two vendors (typically Cisco +1) and all are beaten by Ruckus in performance at the client level. Our top resellers are now starting to win very large (4000+ APs for example) projects where Cisco should be a shoe-in, purely down to the Ruckus AP performance. The sales don’t lie!!


    • Devin Akin says:

      Seriously? This is a discussion about iPads in classrooms. GT made good points. Andrew made good points. I made good points. Not sure what you just did…marketing spew? Throw in a technical point or two, relevant to the discussion, and maybe…just maybe… I won’t ring up Simon and ask him to stick a fork in your arse. 😉 “hundreds of resellers”…you know what that tells me? That Ruckus’s channel fights each other for a few points of margin just like Cisco’s does. Sucky strategy mate. I wouldn’t go around announcing that. Now back to our regulary-scheduled program…iPads in classrooms…and whether or not AAs help…or not.

  9. Mark Julier says:

    Come on Devin, pls don’t slate john for marketing spew.. I’ve heard plenty of marketing BS from you in the past…

    John was actually trying to make a good point, a point that is lost on people that work for a manufacture and only has a narrow minded/blinkered view of the WLAN industry.

    Whilst his comments didn’t meet up with the technical level you were looking for his comments in my mind are better than some theoretical conversion that tried to make sense if a technology will work or not. As GT says there are too many factors involved to make a real argument and you boys will keep arguing till the cows come home.. (ok an English term)

    John talks from real experience that his resellers are experiencing, not from a technical manual. Whilst you and Andrew might be trying to disprove the advantages of AA I think that John hits the nail on the head.

    Simply the advantages of AA over every other manufacture including AH outweigh any disadvantages by far. I ask you to put 30-40 iPAD’s in a classroom and test the throughput across all of them compared to Cisco or AH. Then let me know what you think. In fact I may do this soon as I have another school that is on the 1 IPAD per student program in the UK and can easily test this… ill use a 330 and a 7982.. sounds like a good blog post to me 🙂

    As the sales guys will say themselves, the sales cant lie…

    John will be the first to admit that they have resellers that are not experts in WiFi and reselling Ruckus over other manufactures lowers the risk of issues, simply because the technology just works… No feature cramming, no fancy marketing BS.. just wifi that works. AA, PD-MRC and ChannelFly.. AMEN..

    Am not too sure on your side of the pond (another English saying) but AH and Ruckus resellers do not compete, we are having too much fun picking up business from Meru, Extricom, Netgear, Aruba and Cisco to be dipping into each other’s margins, so am afraid your wrong again pal on this note… might be different in the US.. but not hear buddy.. $$$ or is it ££££

    And before you try and badge me with a Cisco or Ruckus badge, I sell Ruckus, Cisco and AH….

    And if Simon is using a folk, I want a reach-around 😉

    John…yoru right…Sales don’t lie.. marketing does…

    • Devin Akin says:

      Hey Mark,

      Had to look up “slate” as a verb. Learned something. Thanks for that.

      While I’ve been known to give a product pitch or two in my time, admittedly, this is…well, was, a very specific technology discussion, devoid of marketing goo until…well…’that’ happened. I had my engineer hat on, and it was unkindly ripped away. 😦

      Had to look up “blinkered”. Means narrow-minded. Learned something. Thanks again.

      This post is turning into an English-to-American language lesson.

      I disagree that people who work at manufacturers have a “blinkered” view of the industry. On the contrary, we have to have an extremely broad view, but we simply don’t go around saying, “hey, I really think that Meru could make a comeback if they would create ‘Meru Instant'” because that wouldn’t be to our advantage as competitors. Aerohive understands full-well the advantages that Ruckus’s technology has and where and how they execute well in the industry. We watch every nuance of what they do and how they do it…along with every other competitor as well. It’s just not common practice to cheer louder for your competitor than you do for yourself. 🙂

      “til the cows come home” — now that’s language I understand, being from Georgia.

      What you might’ve missed (perhaps by reading between the lines) in the technical banter between GT, Andrew, and me is that Aerohive has already done that testing…or I wouldn’t be making those arguments. 😉 Just because some 3rd party, who has been paid by one of the manufacturers, hasn’t done the testing and written it up in some official-looking document doesn’t mean that the data isn’t real. The tests are easy enough for anyone to do. Ruckus has also done this type of testing as well though, as it’s shown in a recent whitepaper of theirs…so some of our banter is just fleshing out specific points of sales positioning, which likely helped both sides a bit without realizing it. 🙂

      Andrew and I weren’t, in general, trying to disprove the value of AA. The specific technical point I made was: In a classroom of iPads, with one-AP-per-classroom, AA adds no meaningful value. I stand by that assertion. I can prove it all day long. GT, you, John, or God himself (a close personal friend) can try to take the argument elsewhere by throwing in additional variables, and that’s AOK with me, but if you stay within these confines, I’m right. Additional variables then bring in various strengths of both Ruckus and Aerohive that can be fleshed out in various ways for competitive analysis…and that’s cool.

      Sales has no bearing on the technical accuracy of this blog or the arguments made herein. All of that is just irrelevant spew. Do your tests and holla back. You’ll find that regardless of whether you use Ruckus or Aerohive in that classroom, regarding speed, you’ll have a tie on things like downlink video streaming and the like — unless one vendor or the other has a code bug in that rev or such. The reason is that the iPad is the bottleneck, not the infrastructure. If I wanted to spew, I would now take this opportunity to start talking about all of the feature advantages Aerohive has over Ruckus in the Education market and how our EDU sales FAR outweigh Ruckus’s worldwide, but that’s not the point of this discussion now is it?

      I caution against having Simon quite that close. 😉


    • Hi Mark,
      Just a brief comment. I’m not trying to “disprove” the advantages of AAs. I’m simply trying to bring a balanced view to both their benefits and drawbacks. AAs have both, and I think a good understanding of pro’s and con’s are important.

      And I also believe in real-world testing under real-world client capacity and load. A single AP test means almost nothing to me if it will be deployed in an enterprise environment rather than a home environment. I think we all agree on that point 🙂 The overall performance of a “system” of APs is critical.

      I was also speaking specifically on adaptive antenna technology, NOT a comparison of vendors. I’ll leave that to a “Devin and GT battle-royale” if they so choose.


  10. James says:

    As someone who has actually tested 6 vendors with iPads, I can tell you there is significant variation in achieved speeds, from less than 25Mbps to 39Mbps. Ruckus is one of the best ones we found, but Aruba recently pipped them at the post. We are looking at one AP per classroom, but 5GHz only for the iPad SSID.

    • gthill says:

      Would you mind sharing what model APs you used from each vendor? You don’t need to list the observed speeds; just curious as to models used.


      • James says:

        Let’s see – Aruba AP-105, AP-135, AP-134. Meru AP320, AP433, Cisco 1252, 3502, 3602, Enterasys AP3610, Ruckus 7962, 7982, 7363, Aerohive AP120. Wow, that’s actually quite a lot of APs.

        One note in particular – the Aruba AP-135 performed worse than the AP-105, in part because it’s internal antennae are slightly downward pointing. The best result was with the AP-134 which is the same internals, but with external antennae. Our test setup was three classrooms with three APs and 52 iPads. The AP-135 couldn’t handle clients in other classrooms well due to its antenna configuration. This was all 5GHz load balancing, no 2.4GHz was enabled as we found it was pretty bad for bandwidth and with poor radio load balancing. So IMHO AP load balancing is more important than radio load balancing, as the latter is useless for iPads doing video.

        You can see the 1Mbps CBR (plus 256kbps sound) H.264 video at http://alfirk.ccgs.wa.edu.au/ipad/

      • Hi James,
        I’m curious, did you test a single AP in isolation, or a complex real-world environment of multiple APs with each carrying a normal client and throughput load? I think it’s important to test real-world network performance, and find that single AP performance is usually irrelevant in enterprise networks.

        I’d love to see you test Aerohive AP 330s and 350s for an accurate comparison based on the models you tested from other vendors.

        Also, props on actually using a CBR video rather than a VBR video stream! Most people don’t realize the importance.


      • James says:

        Andrew: I’m not interested in testing Aerohive, last time we did I had 2/4 APs fail, and at the time the Australian support seemed to be one guy. Maybe things have changed now, but we’ve finished testing and are gathering quotes.
        I did say we used 3 APs and 52 iPads on 5GHz only, although I didn’t say we did get 90-115Mbps overall for those vendors who performed well using a single AP. It wasn’t real-world (although our existing wireless was running on other channels), but anything with 2×2 MIMO performed fine on all vendors, and we are really focussed on high-quality iPad coverage as we have 700 iPads and are getting a few hundred more next year.

  11. Kalyan says:

    Sure Andrew, I think the interference will increase in the neighbor cell due to adaptive antennas. I don’t think anyone should deny that (based on your sketch) 🙂
    But this interference will be much more intermittent when compared to omni antennas which blast the same amount of signal all the time.

    • Hi Kalyan,
      IMO omnis are more predictable and AAs are less predictable when it comes to co-channel interference levels. Are you saying that more intermittent and less predictable levels of interference are a good thing? I’m just trying to clarify your position.

      IMO, more predictable results can be planned for in the design and are preferred for consistent network performance.


      • gthill says:


        Are you basing your opinions on real world testing with Ruckus gear or theories only? It goes back to what I said way back when. The effect of AAs on networks are difficult (for me anyway) to predict in theory because there are so many factors at work.

        By no means do I think they are 100% good with no bad. That would be spectacular but I don’t think that’s realistic.

        We (well, teams at Ruckus) do a LOT of performance testing because we are such a performance based company. What we see, as do most of our perspective customers is that our systems (not just AAs) do increase range, throughput and capacity.

        That is why it is a large part of our marketing and sales tactic to actually get people to test it. We want people to test it because we think the results speak for themselves.


  12. Well… you guys got me thinking…when the school year starts up again I will test several scenarios by changing the number of Ruckus APs across several classrooms. I can easily change the density on the fly by turning radios on and off from the controller. The only thing I can’t control will be the client devices, ~ 40-50 ipads + at least 10-20 smart phones. The school boards I have are pretty accommodating so it shouldn’t be too hard.
    The adaptive array adjusts for interference and I suspect that we can get them pretty close without significant performance issues. I have another school board deploying ~ 30 schools this summer which makes it easy to pick a challenging classroom layout.

  13. Johnny says:

    Dave , did you tested it ? Could you share your thoughts and results?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: