Lower frequencies do have lower free space loss, but for the same size antenna you have less antenna gain. And with 2 antennas (xmt and rcv), antenna gain wins. All else being equal, higher frequency usually wins. Of course with TVWS you usually accept using ginormous antennas.
I think people are telling you that TVWS is a niche technology, one that isn't even a clear winner in its niche, and shouldn't be used outside its niche. If you have clear LOS, use something else. If you have 99 NLOS customers and 1 who happens to have LOS, I guess you could put him on the TVWS system too. -----Original Message----- From: AF <af-boun...@af.afmug.com> On Behalf Of D. Bernardi Sent: Tuesday, June 23, 2020 10:09 AM To: AnimalFarm Microwave Users Group <af@af.afmug.com> Subject: Re: [AFMUG] TVWS feasibility Clearly RF isn't my specialty... Instead of SNR I guess I really meant noise. If the noise floor is equal wouldn't there be less attenuation of the signal in an open environment (resulting in a better SNR)? At 10:41 AM 6/23/2020, you wrote: > > On Jun 23, 2020, at 10:32 AM, D. Bernardi <dberna...@zitomedia.net> wrote: > > > > > > > > I was thinking more in terms of foliage or other object density, > or mountains/hills, to help estimate range. Wouldn't TVWS still have > better performance in an open area compared to dense forest given > equal SNR? > > > >If SNR is identical then you will get identical performance, >assuming the same channel size and modulation. TVWS channel size >is considerably smaller than the higher frequency alternatives and has >lower modulation levels (at least that I have seen). > >Mark >-- >AF mailing list >AF@af.afmug.com >http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
