Dear Mikrotik support.
As am a mikrotik user for Routers and Wireless devices, am facing problems in all my link devices.
In our country we have big noise, my links are netmetal.
like now I have link 2 mikrotik dish's and 2 netmetal for 20 kilo meters, I search all frequencies , the best frequency I found it gave me 100Mbps send with about 10 Mbps receive , but suddenly its down to 1Mbps, and no frequency then gave this throughout.
Is their any special license that gave special feature to get solution for this problem ?
Please need reply ..
Thanks.
Best Regards.

A couple of options are.
1) Use NV2 ( it is more robust in noisy environments )

2) You could use narrower channel spacing. Instead of using 20MHz use 10 or 5 MHz( If using 2GHz area, set to using G or N mode or combination, but you will need to test in your area and your setup). This increases the energy per bit (http://www.gaussianwaves.com/2008/11/re ... and-snr-2/)  given the same TX power level improving signal. This may decrease total bandwidth, but will improve signal reliability.

3) If you use 5 or 10 MHz spacing, you may be able to use superchannel and squeeze between frequencies e.g half channel steps e.g.  >2412 and 2484< as long as you stay within your counties allowable ISM band. This might help with avoiding interference.

Dear killersoft,
am already using NV2 in my all links,
I use 5Ghz with super channel , and not 2Ghz channels. (N & AC Band)
Thanks.

my links are netmetal 921UAGS-5SHPacD

Hi, (noted on 5GHz. You should still be able to use smaller bandwidths)..

Can you change polarity of the antenna's e.g. vertical to horizontal polarization... Generally if you use horizontal you can get 20 to 25dBm isolation between polarization, depending on antenna design. This alleviates noise(which is commonly vertically polarized, as most people at home have there antenna's in a vertical polarity). This might better you noise floor giving you a better signal to noise ratio..

This polarization however only works well if your only using 1 chain ( 1 antenna polarization  per radio antenna connection). If your antenna & radio already is utilizing both pol's then there is little the above will fix.

Cheers
Greg

Thank you MR. killersoft.
what you mean is in this guide 
https://www.google.com.lb/url?http://i. ... 152145.pdf
right ? okay I will test it ,
also is there any another trick ? like using 2 dish's for 1 netmetal or some thing else ? and whats about channels table in wireless table that you can add new wireless channel ? what its benefit ?
Thank you.
Best regards.

and is there any way to convert to GHz other than 5GHz or 2GHz in mikrotik links ?

Hi
If you use an antenna like this  http://i.mt.lv/routerboard/files/DPA-SL ... 152145.pdf  then both polarizations are integrated into the one antenna. What you may find is if you enable 2 chains in your netmetal that possibly signal levels from one of the chains(polarization) will be better than the other chain (usually shows as an increase in signal to noise level on one of the polarization links(chains)  this would be quite true in RF noisy environments.
There is no device available for conversion of 5GHz to 2 GHz or vice versa, that said yes you can use RF mixers, oscillators and amplifiers, but lets not over complicate the matter !
If you need to use another band, you will need to buy the 2GHz metmetal or 5GHz netmetal and matching antenna's..
On the topic of antenna's, make sure for that 20Km link that you are using the highest gain(Parabolic) antenna for the frequency you are using. for 2GHz that would commonly be at least(minimum) a 24dBi gain parabolic dish antenna, and for 5GHz at least a 30dBi(minimum) gain parabolic dish. This allows for best signal level to reach either end, and minimise noise caused to other users due to a tight beamwidth of such high gain antenna's. You also benefit from a good front to back ratio with those antenna's helping eliminate some background noise which decreases your signal to noise ratio's and thus your ability to get a good data rate. TX power can of course be played with, but that's for another conversation !