-----Original Message-----
From: Af [mailto:af-boun...@afmug.com] On Behalf Of Craig Baird
Sent: Saturday, April 16, 2016 10:04 AM
To: af@afmug.com
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 <fai...@snappytelecom.net>:
> 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
>
>
