Wireless Service Providers → Multiple antennas on the same mast... maybe a problem?

I have three towers.

Tower #1 - Radio #1 - Bullet M2 HP - Channel #8 - AP mode
Tower #2 - Radio #2 - Bullet M2 HP - Channel #8 - Station mode
---switch---
Tower #2 - Radio #3 - Bullet2 HP - Channel #1 - AP mode
Tower #3 - Radio #4 - Bullet2 HP - Channel #1 - Station Mode.

I'm getting excellent signal strength from all radios. When I connect my laptop via the switch, I get 16Mbps+ through the Radio #1 - Radio #2 link. However, if I connect to Radio #3 via wireless... I'm only getting sub 1Mbps speeds.

I have four 24dbi directional grids for the links. On tower #2, I have both 24dbi antennas mounted on the same mast, one three feet higher than the other. One antenna pointing to Tower #1, the other pointing to Tower #3. Roughly at a 120 degree angle from each other.

What am I doing wrong? Tower #2 is in the middle of a field so there isn't any other signals out there to get in the way.

Sorry if this is a newb question.... I'm so close to getting fast speeds to Tower #3......... As you can tell, I'm not in the WISP business.

I think I'm answering my own problem. I need to separate the antennas by 10'. Horizontal and Vertical. Am I correct?

I don't think anyone will tell you you need ten feet

I seen many situations with just a couple of feet vertical was ok
(with channels spaced apart as much as possible)

Might be something else. Have you tried the ubnt forum and posting your config files?

We all want to install something that looks like a canopy 6 pack of antennas, but out in 802.11abg world we need physical separation to prevent self interference. Others on this forum could give you more ideas on reducing interference, but good old distance seems the most reliable.

hope this helps,

Pat

If you are using omni's, then having them directly above each other is best
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Or if they are sectors then i think most people try to get 6 feet and have adjacent unit's channels as far apart as possible, with units on the opposite side of the pentagon being on a different polarity since their channels may need to be closer

Something like
Radio 1 to 2: Channel 2 horizontal
Radio 3 to 4: Channel 11 vertical

Since they are directional grids, 3 to 4 feet of vertical separation should be good.

If this still doesnt work, switch off radio 2 and plug into the switch. Try and do a speed test across the 3/4 link and if you still have problems then you know its not interference.

What distance and frequency are you using? 2.4 or 5.8ghz?

I haven't posted on the Ubilquiti forums because I replicated the problem with another brand 2.4Ghz AP. They are all 2.4Ghz radios.

Radio#1 - Radio#2 = 6.1 miles
Radio#3 - Radio#4 = 1.2 miles

I'm going to physical separate the antennas by 10' horizontally and see what happens. They're mounted on a grain tower with a 8x8 platform on the top. If I mount on the diagonal corners of the platform, that's 10' apart.

Also what happens if you switch to 10mhz wide channels?

I am really keen to find out what happens if you turn off radio 2 still. Oh you also might need to change one of the links to WDS. Wireless networks sometimes have problems with unrouted networks sending data across 2 standard non-wds links in a row.

What are you getting for signals across these links? If they are above -60 then you should be turning the power down. In all reality you should not be walking on yourself that bad given the channel separation.

At close range, as in the same area on the same pole, H Vs. V. may not give you that much of a change. But I hate to say that's why most of us use 5Ghz for Back hauls, and 2.4 for clients, or a combination of the two depending on the situation. Is there any particular reason why you are using an "in-between" channel for radio #1?? If you could use #11 that may give you a bit more separation, and help.

I would have to con-cure with raytaylor there also. This can greatly depend on how your are configuring your network's IP layer also. Bridged Vs. routed and everything in between. Maybe do some traceroutes and see where things get funky, might help with that.

I now have 16Mbps over the Radio #3 - Radio #4 link. I had to lower the Bullet M2 HP units channel width down.

Thanks for the tips.