[Cerowrt-devel] [Bloat] sqm-scripts on WRT1900AC

Mon Jun 1 04:47:56 EDT 2015

Again, my take on it.

Mimo is using multipath to enhance signal and date rate. Basically multiple
antennas for tx and rx to leverage multipath propogation. But its always
between one ap and one client at the time, standard wifi stuff.
Mu-mimo is the same mimo effect, but it can talk to multiple clients at the
same time. Current wave 1 802.11ac chips only supports mimo and mu-mimo
will come in wave 2, I guess this autumn will see releases from the OEMs.

And Wikipedia does a much better job explaining it, than I can :)

http://en.wikipedia.org/wiki/Multi-user_MIMO

Pedro

On Fri, May 29, 2015 at 10:26 PM, David Lang <david at lang.hm> wrote:

> I'm not sure what the difference bwtwen mimo and mu-mimo is, pointer
> please?
>
>
> David Lang
>
> On Fri, 29 May 2015, Pedro Tumusok wrote:
>
>  From my understanding you need an AP that supports mu-mimo and then you
>> have different scenarios of of how to support clients. If the client
>> supports mu-mimo then you get the "full" mi-mimo experience. If the client
>> does not support it, you do not get the "full" mu-mimo experience for that
>> or those clients.
>>
>> Example if you got an 8x8 mu-mimo ap, then you can for instance use 4 of
>> those 8 for a mu-mimo setup and the last 4 can be used for 4 groups of
>> single stream connections or one 3x3 and 1x1. And probably many more
>> combinations like that.
>> But I might be way off on this, do not have any wave 2 products to play
>> with yet.
>>
>> Pedro
>>
>>
>> On Fri, May 29, 2015 at 11:09 AM, David Lang <david at lang.hm> wrote:
>>
>>  Ok, I think I'm understanding that unless the client is mimo enabled,
>>> mimo
>>> on the the AP doesn't do any good. I'm focused on the high density
>>> conference type setup and was wondering if going to these models would
>>> result in any mor effective airtime. It sounds like the answer is no.
>>>
>>> David Lang
>>>
>>>
>>> On Fri, 29 May 2015, Pedro Tumusok wrote:
>>>
>>>  Is the 1900AC MU-Mimo? If not then its still normal Airtime limitations,
>>>
>>>> unless you consider concurrent 2x2 2.4GHz and 3x3 5GHz as a MU setup.
>>>> Also there are very few  devices with builtin 3x3 ac client. From the
>>>> top
>>>> of my head I can not think of one.
>>>>
>>>> Pedro
>>>>
>>>> On Tue, May 26, 2015 at 1:55 AM, David Lang <david at lang.hm> wrote:
>>>>
>>>>  looking at the 1900ac vs the 1200ac, one question. what is needed to
>>>>
>>>>> benefit from the 3x3 vs the 2x2?
>>>>>
>>>>> In theory the 3x3 can transmit to three clients at the same time while
>>>>> the
>>>>> 2x2 can transmit to two clients at the same time.
>>>>>
>>>>> But does the client need specific support for this? (mimo or -ac) Or
>>>>> will
>>>>> this work for 802.11n clients as well?
>>>>>
>>>>> David Lang
>>>>>
>>>>>
>>>>> On Sat, 23 May 2015, Aaron Wood wrote:
>>>>>
>>>>>  Date: Sat, 23 May 2015 23:19:19 -0700
>>>>>
>>>>>  From: Aaron Wood <woody77 at gmail.com>
>>>>>> To: bloat <bloat at lists.bufferbloat.net>,
>>>>>>     cerowrt-devel <cerowrt-devel at lists.bufferbloat.net>,
>>>>>>     Dave Taht <dave.taht at gmail.com>
>>>>>> Subject: Re: [Bloat] sqm-scripts on WRT1900AC
>>>>>>
>>>>>>
>>>>>> After more tweaking, and after Comcast's network settled down some, I
>>>>>> have
>>>>>> some rather quite nice results:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> http://burntchrome.blogspot.com/2015/05/sqm-scripts-on-linksys-wrt1900ac-part-1.html
>>>>>>
>>>>>>
>>>>>>
>>>>>> So it looks like the WRT1900AC is a definite contender for our faster
>>>>>> cable
>>>>>> services.  I'm not sure if it will hold out to the 300Mbps that you
>>>>>> want,
>>>>>> Dave, but it's got plenty for what Comcast is selling right now.
>>>>>>
>>>>>> -Aaron
>>>>>>
>>>>>> P.S.  Broken wifi to the MacBook was a MacBook issue, not a router
>>>>>> issue
>>>>>> (sorted itself out after I put the laptop into monitor mode to capture
>>>>>> packets).
>>>>>>
>>>>>> On Sat, May 23, 2015 at 10:17 PM, Aaron Wood <woody77 at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>  All,
>>>>>>
>>>>>>
>>>>>>> I've been lurking on the OpenWRT forum, looking to see when the CC
>>>>>>> builds
>>>>>>> for the WRT1900AC stabilized, and they seem to be so (for a very
>>>>>>> "beta"-ish
>>>>>>> version of stable).
>>>>>>>
>>>>>>> So I went ahead and loaded up the daily ( CHAOS CALMER (Bleeding
>>>>>>> Edge,
>>>>>>> r45715)).
>>>>>>>
>>>>>>> After getting Luci and sqm-scripts installed, I did a few baseline
>>>>>>> tests.
>>>>>>> Wifi to the MacBook Pro is...  broken.  30Mbps vs. 90+ on the stock
>>>>>>> firmware.  iPhone is fine (80-90Mbps download speed from the
>>>>>>> internet).
>>>>>>>
>>>>>>> After some rrul runs, this is what I ended up with:
>>>>>>> http://www.dslreports.com/speedtest/538967
>>>>>>>
>>>>>>> sqm-scripts are set for:
>>>>>>> 100Mbps download
>>>>>>> 10Mbps upload
>>>>>>> fq_codel
>>>>>>> ECN
>>>>>>> no-squash
>>>>>>> don't ignore
>>>>>>>
>>>>>>> Here's a before run, with the stock firmware:
>>>>>>> http://www.dslreports.com/speedtest/337392
>>>>>>>
>>>>>>> So, unfortunately, it's still leaving 50Mbps on the table.
>>>>>>>
>>>>>>> However, if I set the ingress limit higher (130Mbps), buffering is
>>>>>>> still
>>>>>>> controlled.  Not as well, though.  from +5ms to +10ms, with lots of
>>>>>>> jitter.  But it still looks great to the dslreports test:
>>>>>>> http://www.dslreports.com/speedtest/538990
>>>>>>>
>>>>>>> But the upside?  load is practically nil.  The WRT1900AC, with it's
>>>>>>> dual-core processor is more than enough to keep up with this (from a
>>>>>>> load
>>>>>>> point of view), but it seems like the bottleneck isn't the raw CPU
>>>>>>> power
>>>>>>> (cache?).
>>>>>>>
>>>>>>> I'll get a writeup with graphs on the blog tomorrow (I hope).
>>>>>>>
>>>>>>> -Aaron
>>>>>>>
>>>>>>>
>>>>>>>  _______________________________________________
>>>>>>>
>>>>>> Bloat mailing list
>>>>> Bloat at lists.bufferbloat.net
>>>>> https://lists.bufferbloat.net/listinfo/bloat
>>>>>
>>>>> _______________________________________________
>>>>> Bloat mailing list
>>>>> Bloat at lists.bufferbloat.net
>>>>> https://lists.bufferbloat.net/listinfo/bloat
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>
>>
>>

-- 
Best regards / Mvh
Jan Pedro Tumusok
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