I am not familiar with the hardware nor the intricate specifics.. However I would make a general statement ..
There are a lot of old wives tales associated with licensed link, there may be some context to these old wives tails, most folks in the industry tend to take it for face value, very few end up examining it for merit of correctness. Comments made by folks in the public forums can be the best or the worst of such examples. >From the sounds of it, you have done everything right, and you have the link >working, then anything else would be an old wives tale. BTW, if you were able to get 2x80mhz channels in 11ghz, take a look at what Mimosa B11's can do with them.... and yes these folks did challenge the accepted status quo in licensed links.. 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 ----- Original Message ----- > From: "Craig Baird" <cr...@xpressweb.com> > To: af@afmug.com > Sent: Saturday, April 16, 2016 11:32:09 AM > Subject: [AFMUG] PTP820S 2+0 configuration > So a few months ago we purchased an 11 GHz PTP820S 2+0 link. We > recently installed it, and it appears to be working fine, aside from a > little bit of frame loss that we are investigating. While looking > into this frame loss issue, I stumbled across something that concerns > me. On Cambium's support forum there is a post that states that when > dealing with 2+0 links both radios must be in the same sub-band. > There is no explanation of why this is the case. In our situation, > the radios are in separate sub-bands. When we did the frequency > coordination, the only two 80 MHz channels available were in different > sub-bands. I passed those channels along to our vendor who worked > with Cambium to get a BOM. At no point did anyone say that this was a > problem. So now, fast forward a few months, and I stumble across this > post, and now I'm wondering what the implications will be. Both links > are up and running. Signal on both is right where it should be (-39 > on one, -40 on the other). Both are running at maximum modulation. > There are no defective blocks shown on the radio interfaces. There is > no indication that this sub-band mismatch is causing any issues, aside > from possibly this frame loss thing. However, if I mute the radios on > one link, the frame loss persists, so I don't think it's related. > > In case it matters, the two links are oppositely polarized. On one > side we've got a 2 foot dish with an OMT combining the radios. On the > other side, we've got an 8 foot dual-pol dish. > > So I'm wondering if anyone knows why Cambium says that you can't use > radios from different sub-bands. Are we in for trouble at some point? > > Craig
