Wireless Access

guys, how to avoid interference by electrical pole? even it's not on one line between AP, problem still occurs

How do you know that the electrical pole is causing interference?  Is the pole between your access points and your WLAN clients?

I don't know exactly, just my assumption. because if we test to put an access point where is far from electrical pole it's reachable.

the pole is between two access points

Is this an outdoor deployment?

yes it is, this is an outdoor access points

Okay.  This deserves its own thread, because it is more complicated..

A few questions:

What access points are these?

What antennas?

What areas are you trying to cover?

What access points are these?

- Aruba AirMesh MSR2000

What antennas?

- ANT-2X2-D805

What areas are you trying to cover?

- this AP was used for connection between two office on the small area within 3.1 miles

Did you always have interference or is this something that just started to happen?

that was a second time, first time we meet this issue when we put access point near the generator/power plant on the harbour

Outdoor deployments have countless things to think of when deploying.  Did you reference the outdoor Validated Reference Design Guide on Outdoor Point to Point deployments here?  http://www.arubanetworks.com/technology/reference-design-guides/#Outdoor_Mesh