Have just done an experiment with connecting 2 AP1252 over a 20km distance with the 5ghz radios (Channel 5745).
Each site are connected with two 26dbi flat panel antennas with 0,5m pigtails on antenna A and B connectors. The C connector are disabled.
The results on the root bridge is:
Current Rate (Mb/sec) 6.
Signal Strength (dBm) -69 Signal to Noise (dBm) 32
The result on the non-root bridge is:
Current Rate (Mb/sec) m0.
Signal Strength (dBm) -68 Signal to Noise (dBm) 32
The terrain is relatively flat so this is not perfect for mimo, but shouldnt the data rates be higher on "plain old" 11a rates?
On the specs for the radio recieive sensitivity is -73dBm @ 54 Mb/s.