airFiber - Guide to Co-Location of Multiple Radios/Antennas at Relay Site

Although every scenario will vary on how many radios you can co-locate in one same place, Ubiquiti's airFiber radios have a number of design characteristics that make it ideal for co-location backhaul deployments. Listed below are tips for co-locating AF radios, specifically airFiber 24's:

• In most cases, co-location interference is not a concern because the beamwidth is so narrow (less than 3 degrees). However, to the extent that greater separation (both vertical and lateral) exists between co-located radios, neighbors are less likely to hear each other. About 3-5 meters of separation is good, but 5m+ separation is optimal.
• Co-located AF24 radios are meant to be pointed in different directions to achieve isolation of signals. It is discouraged to point two co-located AF24 radios in the same direction, since this may confuse receiving AF24 radios.
• Co-located AF24 radios must use the same Wireless Mode (Master or Slave). It's discouraged to mix Master and Slave radios at the same tower site.
• Back-to-back AF24 radios can use the same frequency. This is due to the excellent Front-to-Back ratio of the antennas (~70dB).
• Different frequencies are generally recommended for adjacent airFiber radios (e.g., top / bottom, side / side), however, this is not a strict requirement.
• Ubiquiti's HDD mode combined with the GPS Sync technology allows all co-located radios to simultaneously transmit. This is extremely effective in minimizing co-location interference.

By applying these tips, we've seen cases of users successfully co-locating as many as eight AF24 radios on the same tower. Due to numerous differences in link characteristics such as tower height or RF environment, there's no hard / fast rule for the total number of co-located radios.

See this user Community post for a successful AF24 co-location example.