----- > The Mimosa B11 has created this weird myth among WISPs that only it > allows for reuse because WISPs are used to using the same frequency for > TX and RX, but that's not really the case with FDD equipment. ------
I think the myth is in how you are understanding the capability... How you have described FDD operates on channel reuse, has been my understanding as well.. In case of Mimosa, you are actually getting something that has not existed before in the Licensed Radio world... Their radios don't care if they can hear each other.. and they will still operate, co-exist.... exactly how gps sync, channel reuse works in the TDD world... 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: "Seth Mattinen" <[email protected]> > To: "Ubiquiti Users Group" <[email protected]> > Sent: Friday, April 14, 2017 11:30:24 PM > Subject: Re: [Ubnt_users] 4096 QAM (was: 24Ghz link Airfiber) > On 4/14/17 5:09 PM, Faisal Imtiaz wrote: >> I would love to be more 'educated' in this matter... >> >> How exactly is this achieved in real world ? >> I have been told that if another operator is using that channel & polarity, I >> cannot use it in the other direction... >> >> So, technically it is feasible, but practically how is this accomplished ? > > > By designing the path so that they can't hear each other. You can easily > use the same or overlapping frequency pair back to back or any > orientation where it won't pick up the other far side because of > high/low separation. I've got a couple channels that overlap with > another operator, but the azimuth/elevation are different enough (not > back to back) and we're both using 3' Radiowaves antennas with deep > shrouds. Among other things, the shrouds reduce sidelobes. Good antennas > make a difference. > > Two or more "high" side or "low" side radios together won't interfere > since they can't tune the RX side in the same part of the band. That's > how FDD reuse works. A "high" side radio is deaf to anything else in the > "high" side, it only hears a matching "low" side radio. Obviously the > paths have to be different enough that each tower radio won't hear the > other's far side. If you mix high/low at the same location that's when > you run into trouble by creating a situation known as "bucking". > > GPS sync in TDD where you're having to use the same frequency for TX and > RX syncs all the TX together so you don't have one radio in TX while > another nearby is in RX, thus causing interference. But since FDD has > frequency separation this is not a problem. Think of FDD radios together > at a tower as always only in TX mode. > > The Mimosa B11 has created this weird myth among WISPs that only it > allows for reuse because WISPs are used to using the same frequency for > TX and RX, but that's not really the case with FDD equipment. > > ~Seth > _______________________________________________ > Ubnt_users mailing list > [email protected] > http://lists.wispa.org/mailman/listinfo/ubnt_users _______________________________________________ Ubnt_users mailing list [email protected] http://lists.wispa.org/mailman/listinfo/ubnt_users
