Yes, it is.
We have since some weeks 50 (!) Mikrotik SXT5-Lites (well, even some rb411 and 711 and 911 amongst them) connected to an A5-14.
For test purpose we also have 1x SXT5ac-Lite, a QRTac and 2x Mimosa C5’s connected.
I must say that although most ‘promises’ like tdma, GPS sync, MU-MIMO are still in the air, the legacy 802.11 works good.
It works better then Mikrotik NV2’s tdma.
All the clients are connected within a 30 to 400 meter range. In respect of the panels of the A5 I would say the distribution over the sectors is 25-35-30-10%
Before all these clients were connected to 2 Omnitiks, both in a different frequency, one in 20Mhz bandwidth, one in 40Mhz bandwidth channel.
Little by little we ‘handed’ all these clients over to the A5-14 that works with 40Mhz channel.
Because of the higher gain of the antenna (14dBi versus 8dBi) we could tune down most SXT’s considerably down in output power so we reduced the overall noise in the field a lot.
Since radio output of the AP is done by the 14dBi antenna (each panel is 14dBi, losses are 3dB due the misalignment (=Circ. pol versus HV-pol) but these are compensated by the two panels (streams) almost every unit is able to use.
We noticed that where MT need both chains to be working with no more difference than 3-4dB to use them both, the A5 still uses both chains even if the difference is double that… so that’s a first winner.
By reducing the used spectrum from 40 + 20 = 60 to one 40Mhz channel we could creating some ‘cleaner’ spectrum around the clients. Our area still ‘sees’ many other 5Ghz usage. That’s a second winner.
In reducing the SXT’s output levels a lot (most SXT’s went from their default 27dBm to some 13 up to even 8dBm(!) we also made the overall noise less. That’s a third winner.
Since the A5 has much better chipset compared with its better radio and probably better software we see high mcs rates even with signals in -55 to -60dB regions. On the Omnitiks (or Netmetals out in the fields somewhere else for that part) we needed signal levels in the region of -40 to -45 to reach same high mcs rates… So that’s a 4rd winner.
For whatever reason we where never able to ‘pump’ more than some 50Mb aggregated data over an OmniTik or 60-70 on a Netmetal. On the A5 we can easily push up to 200Mbps to one client which gives 200+Mbps aggregated over the A5 while all 50-52 associated clients are still connected and some even functioning… try that with a Mikrotik device! All our other Mikrotik based networks run NV2 but the Mimosa is definitely outperforming them a lot. This throughput gain is probably because of the better chipset and much more powerfull CPU and the ‘cleaner’ spectrum.
Winner no. 5
The ‘normal’ SXT’s (27dBm/600Mhz cpu) we’d used for the clients are mostly able now to saturate their Ethernet port in traffic (up to 95Mbps). On MT networks we never saw that in PtMP.
We also hooked up one SXTac to see it that would do better but never reached more until we realised it still has a fast-Ethernet port only. 95-99Mbps…
So we hooked up a QRTac that has a gigabit port, and yes, 180, 200Mbps download. (For this test we’ve set the A5 to use 80Mhz wide channel. In 40Mhz the speed was still some 150Mbps…
What we also see as a big benefit is the fact that it seems the A5 adapts better to each CPE’s link characteristics. MT in that case struggles to give a poor link client a good CCQ and it delays the rest of the network (in tdma mode) where the A5 hardly seems to be bothered by one or two poor performing clients. Others still get high throughput.
The A5 works in ‘interop’ mode which means csma rts/cts needs to be activated in all CPE’s (set it with the lowest Hw. Protection Threshold = 256 so it is always ‘on’) to avoid the ‘hidden node’ collisions.
We tried to reduce power of the CPE’s even more, so they all hit the A5 with -60 to -65dB signals and each CPE would still get mcs rates 4-5 (single stream) but the moment two or more CPE’s were tested the overall network speeds collapsed completely.
Probably because the low output levels of the SXT’s avoided each CPE’s signals to reach all other CPE’s in the network, a necessity for rts/cts to work.
Although the overall ‘noise’ would be even lower, the network collapsed due the ‘hidden node’ effect that could not be solved by the rts/cts csma system.We increased the output levels again and it seems the network runs pretty stable now for some days.
Thus now we are thinking of replacing more Mikrotik AP’s for Mimosas… but there are some caveats…
Some of our AP’ are in close range of each other. GPS sync would be ideal to preserve as much as possible spectrum as we can so we can start working more in 40 or even better, 80Mhz wide channels. And to avoid tower or close range own, or 3rd party, network interference.
BUT, that can only be done by tdma protocol and that can only work in a full Mimosa environment… and now the costs are going to fly through the roof…
For the price of one C5 with a G2 (that has advantages of its own like continuously scanning frequency usage with auto channel swap) we can buy 3 SXT’s…
Our funds are simply not deep enough to achieve this overnight. At the same time we have to realise we are presently working in a max 20Mb to the client network. Having all Mikrotik AP’s replaced by Mimosa would cost us something but we can increase these speeds to 50Mbps with burst into 80Mb or so and at the same time have more clients per AP. This would be economically feasible and we would stand out of the competition as a WISP.
In going to a full Mimosa deployment we could serve clients an extra 100Mbps in top speed. That would put us even more out of the competition but against a huge investment level from our side the client is probably not willing to bear…
My overall conclusion for now is that the A5 in itself is worth the extra money. I haven’t seen such a powerful device before. It can stand the comparison with a tdma network easy, even in ‘interop’ mode comparing to tdma…
A full syncd Mimosa tdma network is something to dream of I’d guess…
Our next setup planning is one or two A5c’s back to back each connected to two 2x2 Mimo sector antenna’s in a full HV-pol. Mikrotik environment at medium to long range environment.
The idea is that with 2 x 100º RF element’s sectors we could cover some 200º of range with some 17dBi antennas in one frequency (the A5c’s are 4x4 and with 2xMimo we actually get two 2x2 sectors fully syncd.)
A tower could this way with 2 A5c’s in two frequencies in 80Mhz band serve some 150-160 clients and assign them with 15Mb guaranteed and up to 50-100Mb burst download capacity.
I don’t even see a way of doing something similar with 4 Netmetals. These would need twice as much spectrum and still each AP would not reach such high throughput…
On a scale of 0-10 my satisfaction of the A5 would be a 8. A full Mimosa with GPS sync and tdam would make a 10 but due the price a correction to a 9.
If Mimosa could bring the price down of their C5 CPE by 50% and the GPS/tdma would be out, it will be a 11 score system!
One last remark; Although the A5 is circ. polarised and the Mimosa C5’s we’d used for test purpose (2) are 45º slant, we tested all SXT’s and the QRT in HV-pol setup.
We actually set one SXT in a 45º slant setup too (RF elements have an adapter you can use for that) but we saw no significant difference between a normal fit SXT and this 45ª slant SXT.
The Mimosa C5’s are also not doing any better than the QRT. Which makes sence. The QRT has 24dBi gain and a powerful 720Mhz cpu. and narrow beam. Apart from the slant versus HV there will not be so much difference between the two.