>> I’ll stand by the conclusion based on our experience. I am not countering your conclusion based on your experience. I am suggesting that you look a bit more under the surface to determine the coarse parameters which are the actual cause for your experience and observation. (and not just the mere freq /band )
Regards Faisal Imtiaz Snappy Internet & Telecom http://www.snappytelecom.net Tel: 305 663 5518 x 232 Help-desk: (305)663-5518 Option 2 or Email: [email protected] > From: "Rory Conaway" <[email protected]> > To: [email protected] > Sent: Sunday, January 21, 2018 11:40:11 PM > Subject: Re: [AFMUG] Quick comparison between 80GHz and AF24 > Yea, next time I do a White Paper, I’ll let you know. The reality is that few > of > us have the time to do a full engineering analysis so we extrapolate from the > information we have. I’ll stand by the conclusion based on our experience. > Rory > From: Af [mailto:[email protected]] On Behalf Of Faisal Imtiaz > Sent: Sunday, January 21, 2018 9:27 PM > To: [email protected] > Subject: Re: [AFMUG] Quick comparison between 80GHz and AF24 > if you want to understand the science behind it .. here is an excellent paper > discussing all aspects ... > https://transition.fcc.gov/Bureaus/Engineering_Technology/Documents/bulletins/oet70/oet70a.pdf > The reason I called your observation anecdotal because a lot of key important > information is missing from your statement, and there is a lot of 'assumed' / > presumed information left to the readers imagination. > Let me try to explain it further .. You are comparing to radios of different > bands, with different TX powers, Different RX Gain Antennas, on two links, > without any confirmation of your signal levels, rain fade loss, alignment, > actual modulation drop etc etc etc .. and you are making a statement that > higher freq is more stable at a shorter link than a lower freq on a longer > link > (which by itself as a general statement would be true, however you are > expounding it by stretching both freq links to be of a size that will be > affected by Rain Fade, regardless). > Now if you were to actually look and understand the science behind it all, you > will quickly find that your observation is in direct conflict of actual > science, for the two links your are actually comparing.. Thus leading to a > logical conclusion that in your observation, there is some other factor (such > as the ones I mentioned above) must be creating the observed behavior. (and we > are not even going to into the discussion of 'rain drop size, density, and > even > spread across any particular region). > Thus , I refer to your observation as being anecdotal ! :) > :) > Faisal Imtiaz > Snappy Internet & Telecom > http://www.snappytelecom.net > Tel: 305 663 5518 x 232 > Help-desk: (305)663-5518 Option 2 or Email: [email protected] >> From: "Rory Conaway" < [email protected] > >> To: [email protected] >> Sent: Sunday, January 21, 2018 6:51:34 PM >> Subject: Re: [AFMUG] Quick comparison between 80GHz and AF24 >> What are you talking about, anecdotal? I’ll provide more complete information >> for you then. >> I’ve got 5 AF24 links in the same area with varying distances from 800’ >> (although that one was replaced with a B5-Lite last year) to 2.47 miles. The >> only one that goes down is the 2.47 mile link and even then it’s about twice >> a >> year for about 20 minutes during monsoon season. I think I have some pretty >> objective data since they are all within 3 miles. I don’t have a 2.5 mile >> 80GHz >> link in that area so no effort was made to compare. The 2 mile link on this >> particular 5-hop system has not gone down. This has been up for 2 years so we >> have 2 summers of monsoon data. >> Rory >> From: Af [ mailto:[email protected] ] On Behalf Of Faisal Imtiaz >> Sent: Sunday, January 21, 2018 1:46 PM >> To: [email protected] >> Subject: Re: [AFMUG] Quick comparison between 80GHz and AF24 >>>> I’ve got an AF24 that will drop at 2.5 miles for about an hour a year. >>>> I’ve got >> >> a 39GHz link at 2 miles that seems pretty solid also >> This is exactly the type of anecdotal observations that I made reference to >> earlier :) >> Regards. >> Faisal Imtiaz >> Snappy Internet & Telecom >> http://www.snappytelecom.net >> Tel: 305 663 5518 x 232 >> Help-desk: (305)663-5518 Option 2 or Email: [email protected] >>> From: "Rory Conaway" < [email protected] > >>> To: [email protected] >>> Sent: Saturday, January 20, 2018 2:02:53 PM >>> Subject: Re: [AFMUG] Quick comparison between 80GHz and AF24 >>> I’m in Southern Arizona so heavy rain is pretty brief but also why I’m >>> asking >>> the question. I’ve got an AF24 that will drop at 2.5 miles for about an >>> hour a >>> year. I’ve got a 39GHz link at 2 miles that seems pretty solid also but I’m >>> open to using that at 3.5 if that has a better chance too. >>> Rory >>> From: Af [ mailto:[email protected] ] On Behalf Of Mike Hammett >>> Sent: Saturday, January 20, 2018 11:07 AM >>> To: [email protected] >>> Subject: Re: [AFMUG] Quick comparison between 80GHz and AF24 >>> Trango's initial 24 GHz radio could do that. >>> ----- >>> Mike Hammett >>> Intelligent Computing Solutions >>> Midwest Internet Exchange >>> The Brothers WISP >>> From: "Mathew Howard" < [email protected] > >>> To: "af" < [email protected] > >>> Sent: Saturday, January 20, 2018 12:04:15 PM >>> Subject: Re: [AFMUG] Quick comparison between 80GHz and AF24 >>> This is the first I've heard of adaptive channel sizes... I've been looking >>> at >>> both Siklu and Bridgewater, and nobody from either company ever mentioned >>> that >>> (that doesn't necessarily mean they can't do it though). >>> On Jan 20, 2018 11:58 AM, "Mike Hammett" < [email protected] > wrote: >>> Adaptive channel sizes? >>> ----- >>> Mike Hammett >>> Intelligent Computing Solutions >>> Midwest Internet Exchange >>> The Brothers WISP >>> From: "Eric Kuhnke" < [email protected] > >>> To: [email protected] >>> Sent: Saturday, January 20, 2018 11:48:24 AM >>> Subject: Re: [AFMUG] Quick comparison between 80GHz and AF24 >>> This is not extremely new in 80 GHz, just with different and denser >>> modulations. >>> The Siklu 80 GHz stuff has done adaptive coding and modulation for a while. >>> The >>> (now 7 year old!) Bridgewave adaptrate 80 GHz stuff would maintain a 100 >>> Mbps >>> link during a rain fade, by switching a nominally QPSK-modulated 1500 MHz >>> wide >>> channel for 1 Gbps, temporarily down to BPSK during a rain fade event. >>> On Sat, Jan 20, 2018 at 9:45 AM, Stefan Englhardt < [email protected] > wrote: >>>> Some vendors do some new things to stretch the range of 80GHz: >>>> http://de.nec.com/de_DE/global/prod/nw/pasolink/products/ipasolinkEX_advanced.html >>>> ? >>>> They modulate down and then reduce channel size. >>>> This gear is in the 20kEuro Range … >>>> Von: Af [mailto: [email protected] ] Im Auftrag von Faisal Imtiaz >>>> Gesendet: Samstag, 20. Januar 2018 17:08 >>>> An: [email protected] >>>> Betreff: Re: [AFMUG] Quick comparison between 80GHz and AF24 >>>> We have two things to contend with... >>>> one is Oxygen Absorption >>>> second is Rain Fade >>>> Science says, 24ghz has much less O2 absorption fade vs 80ghz >>>> Science also says that 24ghz has slightly less Rain fade vs 80ghz >>>> Science also says that if on a particular link, if one is comparing 24ghz >>>> vs >>>> 80ghz, the difference in which link drops first will be based on the TX >>>> power / >>>> Antenna Gain and Rx sensitivity. >>>> If all things were exactly the same, then 80ghz would drop before 24ghz in >>>> Rain >>>> event. >>>> But in reality, all things are not the same.. I believe 80ghz one is >>>> allowed >>>> more power, and higher antenna gain. >>>> https://www.e-band.com/index.php?id=86 >>>> https://www.linkedin.com/pulse/dont-fall-siklu-overbuilds-distance-claims-david-theodore >>>> at 3.5miles, one is pushing the limits of both 24gzh as well as 80ghz.. >>>> Depending on what you are trying to achieve, and the rainzone, you can make >>>> your choice based on what will perform better normally... cause both of >>>> them >>>> will go out in rain :) >>>> Best of Luck >>>> Faisal Imtiaz >>>> Snappy Internet & Telecom >>>> http://www.snappytelecom.net >>>> Tel: 305 663 5518 x 232 >>>> Help-desk: (305)663-5518 Option 2 or Email: [email protected] >>>>> From: "Mathew Howard" < [email protected] > >>>>> To: "af" < [email protected] > >>>>> Sent: Friday, January 19, 2018 8:42:31 PM >>>>> Subject: Re: [AFMUG] Quick comparison between 80GHz and AF24 >>>>> I'd guess 24ghz would be slightly better, but either one is going to drop >>>>> at >>>>> that distance if you ever get heavy rain. >>>>> Somebody from Siklu told me at one time, that some of their customers >>>>> have told >>>>> then that their rainfade is slightly better than an AF24, but slightly >>>>> worse >>>>> than an AF24HD... how accurate that is, I don't know. >>>>> On Jan 19, 2018 6:03 PM, "Rory Conaway" < [email protected] > wrote: >>>>>> I haven’t run the numbers so please save me some time. Which one has >>>>>> less fade >>>>>> margin at 3.5 miles? I was going to use Siklu with a 2’ antenna. >>>>>> Rory Conaway • Triad Wireless • CEO >>>>>> 4226 S. 37 th Street • Phoenix • AZ 85040 >>>>>> 602-426-0542 >>>>>> [email protected] >>>>>> www.triadwireless.net >>>>>> “"Engineers believe that if it ain't broke, it doesn't have enough >>>>>> features >>>>>> yet." — Scott Adams
