I was thinking more along the lines of something like such... https://media.digikey.com/pdf/Data%20Sheets/Laird%20Technologies/EMI_MicroAbsorb_Cat.pdf
adding plywood infront of the antenna while sounding easy is not the most practical thing to do... depending on where the antenna is mounted.... 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: [email protected] > From: "Gino Villarini" <[email protected]> > To: [email protected] > Sent: Tuesday, January 31, 2017 6:36:27 AM > Subject: Re: [AFMUG] B11, TDMA, and TCP > Attach 1/2” thick plywood to the radome at both ends? > From: Af < [email protected] > on behalf of Josh Reynolds < > [email protected] > > Reply-To: " [email protected] " < [email protected] > > Date: Tuesday, January 31, 2017 at 7:29 AM > To: " [email protected] " < [email protected] > > 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" < [email protected] > wrote: >> Some dampening material in front of the antenna, maybe wood? >> From: Af < [email protected] > on behalf of Faisal Imtiaz < >> [email protected] > >> Reply-To: " [email protected] " < [email protected] > >> Date: Monday, January 30, 2017 at 10:17 PM >> To: " [email protected] " < [email protected] > >> 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: [email protected] >> Gino Villarini >> President >> Metro Office Park #18 Suite 304 Guaynabo, Puerto Rico 00968 >>> From: "Chris Trout" < [email protected] > >>> To: [email protected] >>> 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 < [email protected] > on behalf of Chris Wright < >>> [email protected] > >>> Reply-To: " [email protected] " < [email protected] > >>> Date: Monday, January 30, 2017 at 8:23 AM >>> To: " [email protected] " < [email protected] > >>> 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:[email protected] ] On Behalf Of Chris Trout >>> Sent: Sunday, January 29, 2017 5:39 PM >>> To: [email protected] >>> 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 < [email protected] > on behalf of Faisal Imtiaz < >>> [email protected] > >>> Reply-To: " [email protected] " < [email protected] > >>> Date: Thursday, January 26, 2017 at 10:36 AM >>> To: " [email protected] " < [email protected] > >>> 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: [email protected] >>>> From: "Chris Trout" < [email protected] > >>>> To: [email protected] >>>> 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 < [email protected] > on behalf of "Hardy, Tim" < >>>> [email protected] > >>>> Reply-To: " [email protected] " < [email protected] > >>>> Date: Wednesday, January 25, 2017 at 6:47 PM >>>> To: " [email protected] " < [email protected] > >>>> 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 < [email protected] > on behalf of Chris Trout < >>>> [email protected] > >>>> Sent: Wednesday, January 25, 2017 9:22:14 PM >>>> To: [email protected] >>>> 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 < [email protected] > on behalf of Chris Wright < >>>> [email protected] > >>>> Reply-To: " [email protected] " < [email protected] > >>>> Date: Wednesday, January 25, 2017 at 1:55 PM >>>> To: " [email protected] " < [email protected] > >>>> 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:[email protected] ] >>>> Sent: Wednesday, January 25, 2017 12:35 PM >>>> To: [email protected] >>>> 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: [email protected] >>>>> From: "Chris Wright" < [email protected] > >>>>> To: [email protected] >>>>> 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:[email protected] ] On Behalf Of Faisal Imtiaz >>>>> Sent: Tuesday, January 24, 2017 9:56 PM >>>>> To: [email protected] >>>>> 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: [email protected] >>>>>> From: "Chris Wright" < [email protected] > >>>>>> To: [email protected] >>>>>> 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 < [email protected] > >>>>>> 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: [email protected] >>>>>>>> From: "Chris Wright" < [email protected] > >>>>>>>> To: [email protected] >>>>>>>> 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
