Further note: You can see I did those calcs at 1024QAM, so reduce that down the 256QAM for closer to real numbers :)
On Tue, Feb 13, 2018 at 12:42 AM, Josh Reynolds <j...@kyneticwifi.com> wrote: > Let's break this down a bit. > > Firstly, what outdoor PTMP platform is really using WiFi anymore? *shakes > head* > > Mu-MIMO only works if the clients are sufficiently spread apart > (physically), and their tx/rx windows can fit into almost the same > timeframe. Any degradation in signal of one client that ends up in the > same window as other clients reduces the overall capacity of the AP > (like in many other situations). It can, in some situations, lead to > cumulative transfer windows where overall throughput ends up getting > reduced as the rx/tx hold time for the other clients end up taking a > hit in efficiency. This is one of the few failings of MU-MIMO, not > even taking into account "massive" systems like 14x14 that end up > costing quite a bit in overall power budget due to the number of > elements, further meaning that your range is severely limited in a > system like this... so only decent in very dense situations. That's a > unique niche. > > So, 80 clients. That's a pretty average number for a modern system > (450, Mimosa, AC Prism Gen2). > > 30Mbps per client... okay, but most customers are actually streaming. > Let's throw another margin on top of that and say a few Mbps for > gaming. 10Mbps is a nice round number. Now, that data gets sent in > most services in bursts and buffered, so it's not continuous. Let's > take that average number down to about 8 Mbps. Now let's assume that > maybe 70% of those 80 customers is doing something like that, and > that's probably a generous number. 56 customers. So 56 customers x > 8Mbps = 448Mbps. On a 20Mhz channel? Wait, this doesn't seem to work > out! > > Soo.... 1024 QAM on a 20MHz channel gives you 250Mbps, very roughly. > If you're optimistic about modern patterns, you're between an 80/20 > and a 60/40 Download/Upload ratio on a split GPS synced system. > > 80/20 = 200Mbps Down, 50Mbps Up > 60/40 = 150 Down, 100Mbps Up > > Let's say for the sake of argument that you're in the 80/20 camp, > giving you 200Mbps to work with in above perfect conditions, gives you > 3.57 Mbps per subscriber. Roughly 4M/sub, good for 480p streaming. > > That's a very expensive platform for that kind of throughput and > subscriber count with such limitations in range and needed a "perfect > storm" of client distribution and data patterns to really take > advantage of. With working GPS in all modern platforms, I would be > hard pressed to not use an additional 20mhz channel if available, or > just cut the channel width in half to 10MHz each, and put up 4 Mimosas > or 4 Gen2 Prism radios and have far more than 4x the possible > subscriber account, improved tx/rx efficiency, improved range > (increasing distance and SNR in many situations), and greatly reduced > cost. > > Again, I'm far more excited about the 4x increase in spectral > efficiency via OFDMA that doesn't cause you to cut down on tx/rx > chains for multi-client transmission (costing your range, per client > snr, and per-client throughput in the process). MU-MIMO is and will > always be a niche hack that never lived up to what was promised. > > On Tue, Feb 13, 2018 at 12:12 AM, Sean Heskett <af...@zirkel.us> wrote: >> Being able to load a 450m AP with 80 subs and deliver 30mbps service to all >> of them at peak Netflix time in a 20mhz channel without breaking a sweat is >> worth every penny. >> >> But it’s one tool in the tool box and isn’t the best solution for every >> deployment. >> >> 2 cents >> >> -sean >> >> >> >> On Mon, Feb 12, 2018 at 10:32 PM Josh Reynolds <j...@kyneticwifi.com> wrote: >>> >>> The more I dig into MU-MIMO, the more I realize it's not all that great. >>> >>> I am far more excited by the 9 client simultaneous transmissions in >>> 802.11ax via OFDMA. >>> >>> On Mon, Feb 12, 2018 at 8:00 PM, Adam Moffett <dmmoff...@gmail.com> wrote: >>> > 450 still does a few things that ePMP doesn't. >>> > Plus there's that 14 chain MU-MIMO thing......ePMP will probably never >>> > have >>> > something like that. >>> > UI is still sluggish on ePMP. >>> > >>> > On the other hand ePMP has gotten so many feature improvements over >>> > these >>> > past few years that it's gotten really hard to argue with the value it >>> > provides. >>> > >>> > >>> > ------ Original Message ------ >>> > From: "Chuck McCown" <ch...@wbmfg.com> >>> > To: af@afmug.com >>> > Sent: 2/12/2018 8:27:56 PM >>> > Subject: Re: [AFMUG] mini wisp >>> > >>> > The UI server was probably the worst I have ever seen. >>> > >>> > So, less than 25 subs per site, what speed packages do you sell to those >>> > 25? >>> > >>> > Packetflux GPS sync. >>> > >>> > From: Joe Novak >>> > Sent: Monday, February 12, 2018 5:20 PM >>> > To: af@afmug.com >>> > Subject: Re: [AFMUG] mini wisp >>> > >>> > What didn't you like about it? The interface came a long way since the >>> > early >>> > days of EPMP. We've got quite a bit deployed. A lot of people are having >>> > weird GPS situations come up with the on-board GPS, we have this problem >>> > once in a while too. Our packetflux sites are rock solid though. That is >>> > assuming density isn't more then 25 per AP, because then I don't exactly >>> > have enough experience with it. Most of our APs are sitting right around >>> > 25 >>> > customers, and according to airtime we still have quite a bit of room. >>> > >>> > On Mon, Feb 12, 2018 at 6:09 PM, Jaime Solorza >>> > <losguyswirel...@gmail.com> >>> > wrote: >>> >> >>> >> I separated frequencies to three I found cleanest on AFx5s...On Rockets >>> >> and Powerbeams I choose one frequency and shut off the rest on APs and >>> >> on >>> >> PowerBeams I only use two...this method has worked well since August of >>> >> 2017 >>> >> when I replaced all the radios on this network and have had to change >>> >> them >>> >> since. Two of the WISPs live in Fabens and work with us on issues. >>> >> The >>> >> other one from El Paso uses my services once in a while and works with >>> >> us as >>> >> well. Texas Gas put up allot of 5GHz units around Fabens but still no >>> >> issues. I used larger dishes at Wells and lift stations as well. >>> >> >>> >> Jaime Solorza >>> >> >>> >> On Feb 12, 2018 4:50 PM, "Jaime Solorza" <losguyswirel...@gmail.com> >>> >> wrote: >>> >>> >>> >>> Two AF5x on same tower, One AP on second tower 20 ft away...all other >>> >>> radios within 4 mile radius... >>> >>> >>> >>> Jaime Solorza >>> >>> >>> >>> On Feb 12, 2018 4:43 PM, "Chuck McCown" <ch...@wbmfg.com> wrote: >>> >>>> >>> >>>> All on the same tower, right? >>> >>>> >>> >>>> From: Jaime Solorza >>> >>>> Sent: Monday, February 12, 2018 4:41 PM >>> >>>> To: Animal Farm >>> >>>> Subject: Re: [AFMUG] mini wisp >>> >>>> >>> >>>> Yes..I have two AF5X links as PTP and 25 radios all in 5 GHz off 4 >>> >>>> APs >>> >>>> in Fabens, Texas sharing spectrum with 3 WISPs...no issues... >>> >>>> >>> >>>> Jaime Solorza >>> >>>> >>> >>>> On Feb 12, 2018 4:32 PM, "Chuck McCown" <ch...@wbmfg.com> wrote: >>> >>>>> >>> >>>>> Talking to a friend that wants to build a small wisp. He is about >>> >>>>> 5.5 >>> >>>>> miles from a backbone connection. I would suggest AF5X to him but >>> >>>>> he is >>> >>>>> gonna want to use 5 GHz for his wisp I presume. >>> >>>>> >>> >>>>> Can an AF5X and some 5 GHz cambium (or others) access points >>> >>>>> peacefully >>> >>>>> coexist on a tower? >>> >>>>> Very rural area. Not expecting much interference other than home >>> >>>>> routers. >>> > >>> >
