Just want to point out that this same logic and coding exists in the PMP 450 platform as well.
You’ll see very soon when we release the high gain integrated PMP 450 SM at 3 GHz, it’s H+V, not dual slant, but works equally as well and gives you 19 dBi gain. Matt From: Af [mailto:[email protected]] On Behalf Of Faisal Imtiaz Sent: Friday, December 04, 2015 3:25 PM To: [email protected] Subject: Re: [AFMUG] to slant, or not to slant - that is the question Since inquiring minds want to know... Here is the Word on this topic from Cambium... (While this was titled 2.4Ghz, as per them, it applies to their 5ghz as well). :) 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]<mailto:[email protected]> ________________________________ From: "Joshaven Mailing Lists" <[email protected]<mailto:[email protected]>> To: [email protected]<mailto:[email protected]> Sent: Friday, December 4, 2015 4:15:55 PM Subject: Re: [AFMUG] to slant, or not to slant - that is the question The Atheros chipset differentiating between the Mimo chains does not have to do with 45º slant vs 90º… it means that chain A and B on one radio can be H&V or V&H while chain A and B on the other can be H&V or V&H interchangeably with no loss because and the chip will just cross them over as needed. This means that hooking up the antenna cables “backwards” won’t effect anything. It doesn’t mean that the orientation of the antenna is irrelevant. The energy received by an antenna that is out of phase with another antenna is much less then if it was in phase that is a principal of radio that no chipset will ever overcome. Now… maybe you can make a magic antenna that is “multi phased” such that it can tune in a 45º phase offset signal well. I suspect that the Cambium equipment when properly matched will both have the same polorization. I believe that if your having the same outcome on slant or not slant it would be due to one chain being refracted. For example if your horizontal chain was fine but the virtual chain was refracted off something such that the wave was on or near a 45º slant then you would have the same basic performance regardless of a standard or slant orientation. This however is a path issue not a design characteristic of the chipset or antenna. FYI, linearly polarization is not a reference to the polarization being on a vertical, horizontal or slant axis but a reference to the way the wave propagates, circular polarization is an alternative to linear polarization not “slant". Sincerely, Joshaven Potter MTCNA, MTCRE, MTCWE, MTCTCE, UACA Google Hangouts: [email protected]<mailto:[email protected]> Cell & SMS: 1-517-607-9370 [email protected]<mailto:[email protected]> On Dec 4, 2015, at 2:13 PM, Adam Moffett <[email protected]<mailto:[email protected]>> wrote: The DSP in the ePMP can do some kind of processing to correct for the 45 degree offset when you have slant on one end and V+H on the other. I might not be stating it with the correct technical jargon, but that's the gist of it. They sell a dual slant sector for the AP with the intent to use it with V+H integrated SM. This is a built in feature of the Atheros chipset, so presumably UBNT radios can do the same thing. That all said...I would try to match them up as just a matter of principle. On 12/4/2015 2:07 PM, Joshaven Mailing Lists wrote: Your AP & SM should always have the same antenna orientation. I promise you that you don’t want slant on the AP and not on the CPE. If the signal is so obstructed that the orientation is screwed up to the point that unmatched polarization is actually a benefit then there is something seriously wrong… Sincerely, Joshaven Potter MTCNA, MTCRE, MTCWE, MTCTCE, UACA Google Hangouts: [email protected]<mailto:[email protected]> Cell & SMS: 1-517-607-9370 [email protected]<mailto:[email protected]> On Dec 4, 2015, at 1:59 PM, Paul McCall <[email protected]<mailto:[email protected]>> wrote: We are looking at smaller sector sizes for a 5 Ghz ePMP cluster (60 degree probably), and am considering my options, which might also increase my gain quite a bit. Using a non-Dual Slant sector such as AM-5AC21-60, would increase my options. There have been a calling threads on Cambium’s sites about whether Dual Slant was a big factor at the AP if the SMs aren’t dual-slant. Cambium’s Daniel Sullivan made this comment … The thread was originally about 2.4 Ghz options, so not sure if it applies exactly to 5 Ghz. Paul
