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<mailto:af-boun...@afmug.com>> on behalf of Faisal Imtiaz <fai...@snappytelecom.net<mailto:fai...@snappytelecom.net>> Reply-To: "af@afmug.com<mailto:af@afmug.com>" <af@afmug.com<mailto:af@afmug.com>> Date: Thursday, January 26, 2017 at 10:36 AM To: "af@afmug.com<mailto:af@afmug.com>" <af@afmug.com<mailto: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<mailto:supp...@snappytelecom.net> ________________________________ From: "Chris Trout" <ch...@mimosa.co<mailto:ch...@mimosa.co>> To: af@afmug.com<mailto: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<mailto:af-boun...@afmug.com>> on behalf of "Hardy, Tim" <tha...@comsearch.com<mailto:tha...@comsearch.com>> Reply-To: "af@afmug.com<mailto:af@afmug.com>" <af@afmug.com<mailto:af@afmug.com>> Date: Wednesday, January 25, 2017 at 6:47 PM To: "af@afmug.com<mailto:af@afmug.com>" <af@afmug.com<mailto: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<mailto:af-boun...@afmug.com>> on behalf of Chris Trout <ch...@mimosa.co<mailto:ch...@mimosa.co>> Sent: Wednesday, January 25, 2017 9:22:14 PM To: af@afmug.com<mailto: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<mailto:af-boun...@afmug.com>> on behalf of Chris Wright <ch...@velociter.net<mailto:ch...@velociter.net>> Reply-To: "af@afmug.com<mailto:af@afmug.com>" <af@afmug.com<mailto:af@afmug.com>> Date: Wednesday, January 25, 2017 at 1:55 PM To: "af@afmug.com<mailto:af@afmug.com>" <af@afmug.com<mailto: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<mailto: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<mailto:supp...@snappytelecom.net> ________________________________ From: "Chris Wright" <ch...@velociter.net<mailto:ch...@velociter.net>> To: af@afmug.com<mailto: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<mailto: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<mailto:supp...@snappytelecom.net> ________________________________ From: "Chris Wright" <ch...@velociter.net<mailto:ch...@velociter.net>> To: af@afmug.com<mailto: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<mailto: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<mailto:supp...@snappytelecom.net> ________________________________ From: "Chris Wright" <ch...@velociter.net<mailto:ch...@velociter.net>> To: af@afmug.com<mailto: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<http://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<http://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
