RF absorbing foam can give you whatever loss you desire.
From: Gino Villarini
Sent: Tuesday, January 31, 2017 4:36 AM
To: af@afmug.com
Subject: Re: [AFMUG] B11, TDMA, and TCP
Attach 1/2” thick plywood to the radome at both ends?
From: Af <af-boun...@afmug.com> on behalf of Josh Reynolds
<j...@kyneticwifi.com>
Reply-To: "af@afmug.com" <af@afmug.com>
Date: Tuesday, January 31, 2017 at 7:29 AM
To: "af@afmug.com" <af@afmug.com>
Subject: Re: [AFMUG] B11, TDMA, and TCP
A block of wood you say?
Is this radio a witch!? :-)
Gino Villarini
President
Metro Office Park #18 Suite 304 Guaynabo, Puerto Rico 00968
On Jan 31, 2017 3:24 AM, "Gino Villarini" <g...@aeronetpr.com> wrote:
Some dampening material in front of the antenna, maybe wood?
From: Af <af-boun...@afmug.com> on behalf of Faisal Imtiaz
<fai...@snappytelecom.net>
Reply-To: "af@afmug.com" <af@afmug.com>
Date: Monday, January 30, 2017 at 10:17 PM
To: "af@afmug.com" <af@afmug.com>
Subject: Re: [AFMUG] B11, TDMA, and TCP
Thanks Chris & Chris.. for asking the question I had and answering it. :)
For Chris T.
For those of us for who 10db is till too hot...
Do you think Engineering can come with with some sort of a insert that we
could possibly install in the wave guide .. which could say dampen 3-5 db worth
of Tx Power ?
I think such 'disc' would be very helpful for the short links like the one
Chris & others have ..
Regards
Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232
Help-desk: (305)663-5518 Option 2 or Email: supp...@snappytelecom.net
Gino Villarini
President
Metro Office Park #18 Suite 304 Guaynabo, Puerto Rico 00968
------------------------------------------------------------------------------
From: "Chris Trout" <ch...@mimosa.co>
To: af@afmug.com
Sent: Monday, January 30, 2017 9:00:31 PM
Subject: Re: [AFMUG] B11, TDMA, and TCP
Hi Chris,
Yes, there is a hardware limitation. The diode detectors used in the PA to
control Tx power lose dynamic range at low power. I’ve raised your request to
our engineering team for future product designs.
Chris Trout
Mimosa Networks, Inc.
From: Af <af-boun...@afmug.com> on behalf of Chris Wright
<ch...@velociter.net>
Reply-To: "af@afmug.com" <af@afmug.com>
Date: Monday, January 30, 2017 at 8:23 AM
To: "af@afmug.com" <af@afmug.com>
Subject: Re: [AFMUG] B11, TDMA, and TCP
In my case, even 10dB output on both sides is still too hot. Is the 10dB
minimum power output a hardware limitation or is it possible you can throw that
on the feature requests pile?
Thanks,
Chris Wright
Network Administrator
From: Af [mailto:af-boun...@afmug.com] On Behalf Of Chris Trout
Sent: Sunday, January 29, 2017 5:39 PM
To: af@afmug.com
Subject: Re: [AFMUG] B11, TDMA, and TCP
Hi Faisal,
TPC is designed to do this automatically, but so far we have limited how
much change it can make, and are still tuning its behavior in cases of unequal
power per side of the link, very low RSSI on one or more chains, and very high
RSSI. Some of these changes will be included in the next backhaul firmware
release.
In our experience, targeting 30 dB of SNR per chain results in the best
performance, so for now we recommend adjusting Tx power to get near that level,
and then let TPC manage fine adjustments from there.
Chris Trout
Mimosa Networks, Inc.
From: Af <af-boun...@afmug.com> on behalf of Faisal Imtiaz
<fai...@snappytelecom.net>
Reply-To: "af@afmug.com" <af@afmug.com>
Date: Thursday, January 26, 2017 at 10:36 AM
To: "af@afmug.com" <af@afmug.com>
Subject: Re: [AFMUG] B11, TDMA, and TCP
Hi Chris,
What is the optimum SNR or aka the sweet spot.
Which actually leads to another question which I have...
On my link, I had to manually reduce TX Power to 10dBm (lowest possible) in
order to end up with a SNR of 35/37...
Can we possible see this being done by TPC vs a manual power decrease ?
Regards.
Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232
Help-desk: (305)663-5518 Option 2 or Email: supp...@snappytelecom.net
----------------------------------------------------------------------------
From: "Chris Trout" <ch...@mimosa.co>
To: af@afmug.com
Sent: Thursday, January 26, 2017 12:32:32 PM
Subject: Re: [AFMUG] B11, TDMA, and TCP
Great point, Tim. I have updated our documentation.
Transmit compression starts at 27 dBm Tx power on backhaul products. TPC
backs off from this value automatically if SNR allows.
Mimosa backhaul radios are capable of associating at relatively high Rx
power levels (between -30 and -20 dBm). However, higher power levels cause the
receivers to saturate, and this increases the error vector magnitude (EVM). For
this reason, Mimosa recommends designing links with -30 dBm or lower received
power to avoid saturation.
To optimize RF performance, adjust Tx power on the AP while monitoring
both Rx power and EVM on the Station side of the link. Tx power should be set
to a value that results in the lowest EVM value.
The only reason why some compression or saturation may be acceptable is
in the case of low SNR, which has a larger effect on overall performance.
Chris Trout
Mimosa Networks, Inc.
From: Af <af-boun...@afmug.com> on behalf of "Hardy, Tim"
<tha...@comsearch.com>
Reply-To: "af@afmug.com" <af@afmug.com>
Date: Wednesday, January 25, 2017 at 6:47 PM
To: "af@afmug.com" <af@afmug.com>
Subject: Re: [AFMUG] B11, TDMA, and TCP
Chris,
It might help us design these properly if we knew what the saturation
levels were. We have these for most other radios.
Thanks,
Tim
--------------------------------------------------------------------------
From: Af <af-boun...@afmug.com> on behalf of Chris Trout <ch...@mimosa.co>
Sent: Wednesday, January 25, 2017 9:22:14 PM
To: af@afmug.com
Subject: Re: [AFMUG] B11, TDMA, and TCP
The PHY (Layer 1) is affected by EVM and PER which cause changes in
modulation.
The MAC (Layer 2), where TDMA lives, makes use of the PHY but does not
change it directly.
Changes in the amount and direction of traffic across the link do affect
EVM and PER, however.
It is likely that the PHY rate is more stable on your link at 1300 Mbps
(MCS7) than at 1560 Mbps (MCS8), and Auto TDMA is reacting faster to changing
conditions since it sends a shorter duration of packets for training the PHY
rate.
As others have recommended, reducing power will avoid saturating the
receiver, and reduce (improve) EVM. I think that is what we may be seeing here
on a very short link.
Chris Trout
Mimosa Networks, Inc.
From: Af <af-boun...@afmug.com> on behalf of Chris Wright
<ch...@velociter.net>
Reply-To: "af@afmug.com" <af@afmug.com>
Date: Wednesday, January 25, 2017 at 1:55 PM
To: "af@afmug.com" <af@afmug.com>
Subject: Re: [AFMUG] B11, TDMA, and TCP
Traffic Split set to Auto:
PHY 1300/1300
Traffic Split set to 75/25, 8ms window:
PHY 1560/1300
Anyone can see why one should prefer setting the Traffic Split to 75/25 –
it provides more bandwidth in one direction.
Chris Wright
Network Administrator
From: Faisal Imtiaz [mailto:fai...@snappytelecom.net]
Sent: Wednesday, January 25, 2017 12:35 PM
To: af@afmug.com
Cc: Chris Wright
Subject: Re: [AFMUG] B11, TDMA, and TCP
Hi Chris,
I want to compare something with my link...
Can you please share what's the listed PHY rates were on your PCN for the
link.
Regards.
Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232
Help-desk: (305)663-5518 Option 2 or Email: supp...@snappytelecom.net
--------------------------------------------------------------------------
From: "Chris Wright" <ch...@velociter.net>
To: af@afmug.com
Sent: Wednesday, January 25, 2017 11:21:12 AM
Subject: Re: [AFMUG] B11, TDMA, and TCP
Power is already at the minimum (10dBm) on both sides. 2.2km link.
Chris Wright
Network Administrator
From: Af [mailto:af-boun...@afmug.com] On Behalf Of Faisal Imtiaz
Sent: Tuesday, January 24, 2017 9:56 PM
To: af@afmug.com
Subject: Re: [AFMUG] B11, TDMA, and TCP
>SNR 41, 42, 41, 41
Turn down your power, and bring the SNR in the 30-35 range...
it will improve thruput and allow for the higher modulation.
Regards.
Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232
Help-desk: (305)663-5518 Option 2 or Email: supp...@snappytelecom.net
------------------------------------------------------------------------
From: "Chris Wright" <ch...@velociter.net>
To: af@afmug.com
Sent: Wednesday, January 25, 2017 12:41:37 AM
Subject: Re: [AFMUG] B11, TDMA, and TCP
Firmware 1.4.4
SNR 41, 42, 41, 41
Flow Control had no effect so it remains disabled for now.
Sent via mobile phone.
On Jan 24, 2017, at 9:05 PM, Faisal Imtiaz <fai...@snappytelecom.net>
wrote:
What version for firmware is on the radio ?
and What your SNR on the two chains (both directions, i.e. 4
readings).
I can tell you that we do not see the behavior you are describing
below...
But I can also tell you that we had to do some 'tuning' on settings
including flow control ..
our B11's plug into netonix Switches....
Regards.
Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232
Help-desk: (305)663-5518 Option 2 or Email:
supp...@snappytelecom.net
--------------------------------------------------------------------
From: "Chris Wright" <ch...@velociter.net>
To: af@afmug.com
Sent: Tuesday, January 24, 2017 8:02:58 PM
Subject: [AFMUG] B11, TDMA, and TCP
According to Mimosa, I should be telling my customers that if
they’re using the most popular metric in the world for testing internet speeds,
they’re doing it wrong (I concede that while this may be technically correct,
my customers – and yours too – don’t do technically correct very well.”
When TDMA is set to 75/25, 8ms window, MAC Tx/Rx is 980/290. This
gives me as much Tx bandwidth as I require for peak times, but no one client IP
can download more than 20mbps of TCP traffic (from my speedtest.net at the
edge, nor anyone else’s beyond my edge).
When TDMA is Auto, MAC Tx/Rx is 780/780 (lower Tx, which is
undesirable as it’s 100mbps shy of what I need during peak hours), but TCP
throughput per client is greatly increased (150+mbps).
So I’m in a pickle. Either my scrupulous customers can get those
coveted speedtest.net results they love seeing as they run them every thirty
seconds ad-nauseum at the cost of overall Tx capacity of the link. Or I give
myself some headroom in link capacity but the fastest speeds my 100mbps clients
can see is 20mbps.
What’s even stranger is that client upload seems unaffected. I
can upload 150+mbps from my test on the link no matter what TDMA is configured.
I hit up Mimosa’s chat support was as chipper as they were unyielding in their
idea that I should test in a way that caters to the B11’s shortcomings. I’ve
been a Mimosa fanboy for a while now but boy am I feeling burned right now.
Chris Wright
Network Administrator
