If you have Line of Site paths to a client location you probably can get away with some of the existing bands in 2.4 or 5 GHz and have a lot more throughput capacity and not have to deal with the database. Unless you have horrendous noise levels because of other users the typical unlicensed bands should work fine. If you do have noise problems you are likely in a more populated area and the TVWS channels available for use may be a lot fewer or none available (especially for channel bonding or aggregation).
TVWS frequencies are usually looked at for those longer distance links that also have foliage issues. Those frequencies are less susceptible to attenuation by the trees than the upper bands WISP's traditionally use. LIDAR data in those cases won't be on much value, a traditional RF propagation program will suit you well as it can be tuned for the tree clutter loses in TVWS bands just fine. I personally did some testing with 6 Harmonics a few years ago where we really pushed the limits with tree loss and test signals. The field collected data verified that the RF prediction tools are very capable of making accurate coverage maps for those bands. Thank you, Brian Webster www.wirelessmapping.com -----Original Message----- From: AF [mailto:af-boun...@af.afmug.com] On Behalf Of Mark Radabaugh Sent: Tuesday, June 23, 2020 11:18 AM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] TVWS feasibility Yes - an open area will give you a stronger signal. As long as a radio signal is above the detection threshold (the signal is strong enough for the radio to detect) and the SNR is high enough to support the modulation it will perform to specification (assuming the manufacturer provided accurate specifications). Keep in mind that wooded areas generally attenuate both noise and signal equally. At the customer side receive sensitivity can quickly become important due to the attenuated signals you are trying to detect. At the access point (AP) side (which is presumably not in the trees) SNR is usually a bigger concern. The AP is going to have to be sensitive enough to detect the (tree attenuated) signal coming from the client while still hearing all of the noise that exists in the open areas. Mark > On Jun 23, 2020, at 11:09 AM, D. Bernardi <dberna...@zitomedia.net> wrote: > > > > 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 -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
