Compare Cambium 1000 to Ubiquiti 5ac

Hi all --

I used flexible UL/DL for Cambium 1000 when I am comparing the throughput Cambium vs Ubiquiti; however, at MCS15, Ubiquiti 5ac Lite has 110mbps while Cambium 1000 only has ~95Mbps...is there anyway Cambium 1000 can have over 100Mbps throughput at its highest data rate?

Dawei

You are comparing a 11n based gear with a .ac based gear at lab with optimal conditions with only one cpe.

This does not reflect reality of a WISP.  

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Hello, 

Adding to what ste already pointed out. There are some key differences between .ac and .n when testing under lab conditions:

1. .ac allows 256QAM modulation while .n allows a max of 64QAM. 256QAM provides 33% more throughput than 64QAM, theoritically speaking. And as ste pointed out, this may not be seen in the real word as 256QAM requires much higher SNR than 64QAM which is typically not avaiable in the real world. 256QAM also has limited range. Unless you are doing short links, you may not be able to take advantage of it.

2. On the ePMP are you using the GPS sync unit or one of the other units? Only the GPS sync unit has a GigE port (but see note below on our latest Force products) while the other units have a FE port (10/100). So it may be that you are limited by Ethernet capacity. Even if one of the radios on the link is a FE port, your throughput will be below 100 Mbps. 

And to answer your last question, yes it is possible to achieve more than 100 Mbps with ePMP. Use the GPS sync radio on both ends and use a 40 MHz channel (you may get more than 100 Mbps on a 20 MHz under perfect lab conditions). And lastly, we introduced two new products yesterday, the Force 180 and Force 200 which both come with GigE ports.

Thanks,
Sriram 

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I set the Ubiquiti 5ac max mcs rate = 15, and my point is to get a higher throughput on Cambium when it is on MCS15, which is 110Mbps perhaps.

1. I set both devices's mcs rate are limited at mcs=15, ubiquiti still provides 110Mbps vs 95Mbps over Cambium with the same test set up, does that mean that ac just outperforms n in each mcs rate?

2. I am testing the ePMP1000 throughput on connected test, and I left the gps ports open. And yes the bandwidth I set on both Ubiquiti and Cambium is 20MHz. The new peoducts are definely worth to look.

Is it possible to use gps sync on a pair of Cambium ePMP1000 (sector front and back) to achieve over 100Mbps with 20MHz bandwidth only in field test?

Thanks,

Dawei


@dawei wrote:

1. I set both devices's mcs rate are limited at mcs=15, ubiquiti still provides 110Mbps vs 95Mbps over Cambium with the same test set up, does that mean that ac just outperforms n in each mcs rate?


I would suggest verifying the MCS rates are using the same modulation. This may have changed, but it was my understanding the modulation numbers do not match for N and AC (I believe airMax N MCS15 is equivalent to airMax AC MCS7). 

ePMP 1000 throughput in 20 MHz  is 110-115 Mbps ( 5 ms frame). It is aggregation throughput =   Upload +Download  in duplex.  ePMP is TDD system, and  in  TDD Flexible mode  or ePTP mode  it is able to achive about 90-95%   of aggregation throughput in one direction (simplex) , in DL  is slightly more, in UL - less.  UBNT is asynchronous system, and in one direction it is able to achive about 99% of  it's aggregation throughput UL+DL.

Nevertheless ePMP  ( with 1 GB ethernet )  in 20 MHz,  TDD Flexible should have  DL throughput   slightly above 100 Mbps ( in UDP tests or internal L2 test) and  in TCP test slightly less 100 Mbps. Look at   Monitor -Performance screen, during your test ePMP should have  100%  working time at MCS15  UL and DL.   If you test ePMP in office it is hard to provide stable  DL and UL MCS15  due to multipath signals, that are reflected from office walls  .  To  get  right result  in test you should connect two ePMP units by coaxial cable with attenuators. ePMP works much better in outdoor conditions,  then in office.

UBNT is close to wi-fi systems ( also in Airmax mode) and as any wi-fi it  works   fine in office and worse in  long distance outdoor. So test ePMP and UBNT outdoor and you see that ePMP outperforms  any UBNT based on 802.11N and UBNT AC   at  the same modulation (64QAM 5/6 for example)  and at the same channel bandwidth. Also  ePMP outperforms  UBNT AC  at  256QAM  in real life confidions ( long distance, noisy environment, multipath , etc).  UBNT AC  at 256QAM  is able to get more throughput then ePMP  only in point to point  at   short distance LOS ( about 3-5 km) with high signal RSSI > -50 dBm and CINR>34-36 dB.

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I would suggest verifying the MCS rates are using the same modulation. This may have changed, but it was my understanding the modulation numbers do not match for N and AC (I believe airMax N MCS15 is equivalent to airMax AC MCS7). 

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Hi uberdome --

Good point; however, on the Ubiquiti 5ac Tx rate setting, I do not have much choices but 8x(QAM256), 6x(QAM64)...Cambium did a better job to let I choose exactly the MCS I want from 0 - 15. Also, I just found that sometimes the Switching power supply has Gb and 100Mb different types, that could be one of the cause too.

Dawei

Just tossing in my 2 cents :)  one important fact to know is that required SNR for  100Meg in a 20 MHz channel is roughly  36 (SNRdb) achieving this on either platform in the real world is some times impossible :) and yes that is  counting for the 5/6 FEC of MCS15 when you do the math it boils down to the 99Mbps agg for the channel this is why I suspect Cambium opted to save on cost and only put the FE port on the CPE radios'

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My apologies for my mistake I had an error in my figures 36 is the SNR requirement for  100Mbps on a 10MHz channel 

it would also  require 10bit QAM1024 Coding

you could achieve a  100Meg on 20MHz with 25(SNRdB)   Technically 20(SNRdB) is  good enough however it would be more susceptible to fading. on a 20MHz channel good rule of thumb is to shoot for as close to 30(SNRdB) as you can get.

for anyone who is interested in how these numbers are calculated private message me 

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