What is the affect of fresnel encroachment in this scenario? This is not believable of zero throughout or signal loss....but ok.
Jon Langeler Michwave Technologies, Inc. > On Dec 4, 2015, at 4:25 PM, Faisal Imtiaz <fai...@snappytelecom.net> wrote: > > 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: supp...@snappytelecom.net > > From: "Joshaven Mailing Lists" <lis...@joshaven.com> > To: af@afmug.com > 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: yourt...@gmail.com > Cell & SMS: 1-517-607-9370 > supp...@joshaven.com > > > > On Dec 4, 2015, at 2:13 PM, Adam Moffett <dmmoff...@gmail.com> 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: yourt...@gmail.com > Cell & SMS: 1-517-607-9370 > supp...@joshaven.com > > > > On Dec 4, 2015, at 1:59 PM, Paul McCall <pa...@pdmnet.net> 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 > > > > > <ePMP_2_4_GHz Antenna_Configuration.pdf>
