Hello...
I have a request from a customer to connect between two locations. PTP.
Traffic : 100Mbps
distance : 3KM line of sight ( clear )
location : outside town " low noise"

Hardware suggestion is to use :
1-RB800
2-R52HN Minipci or Dbii F50NPro
3- mimo dish 5.1 GHz to 5.8 GHz 32 dBi ( L-com).
4- Alfa N-type (male) to N-type (male), LMR-4001m low loss cable.
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is it possible?
Please your advices.

I would go with BaseBox5 (912 outdoor) and the corespondent cables. If You need only layer 2 configure wds bridge and disable anything not needed. Should be easy and straight forward job ...

32 dBi definitely too much for 3 km, i think 24 dBi will be enough, for example this:

http://en.jirous.com/antenna-5ghz/jrc-24_mimo/

According to calculator if your freshnel zone is 100% clear, you should get around -60 dBm signal strenght with this pair antenna and the R52nM cards

I have got RB 411GL, on 3 km should be capable 100 Mbit/sec tcp throughput.

32 dBi definitely too much for 3 km, i think 24 dBi will be enough, for example this:

http://en.jirous.com/antenna-5ghz/jrc-24_mimo/

According to calculator if your freshnel zone is 100% clear, you should get around -60 dBm signal strenght with this pair antenna and the R52nM cards

I have got RB 411GL, on 3 km should be capable 100 Mbit/sec tcp throughput.

If you've the place for a 32dBi Antenna just use it
Why:
- narrower beam -> less interference from others
- higher gain -> possibility to turn down tx-power while getting highest modulation -> lower selfinterference

There will be a 30dbi Antenna from Mikrotik with mount for Basebox.
I guess this will be good value for the price.

Thank you guys for all your support. I will install the links and post the result with pictures soon.