Craig my guess would be they meant frequency band, not subband. I can't think of any reason you couldn't use different sub-bands so long as the OMT covers the range (which in the case of 11GHz is most likely covers all subbands).
Daniel White Managing Director – Hardware Distribution Sales ConVergence Technologies Cell: +1 (303) 746-3590 [email protected] > -----Original Message----- > From: Af [mailto:[email protected]] On Behalf Of Craig Baird > Sent: Saturday, April 16, 2016 10:04 AM > To: [email protected] > Subject: Re: [AFMUG] PTP820S 2+0 configuration > > Thanks Faisal. I hope that's the case. If it were just some random person > who made the post, I wouldn't worry so much about it. But the post was > made by one of the Cambium guys themselves. > > Craig > > > Quoting Faisal Imtiaz <[email protected]>: > > > 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: [email protected] > > > > ----- Original Message ----- > >> From: "Craig Baird" <[email protected]> > >> To: [email protected] > >> 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 > > > > > --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
