Why do I get only 1.5 Mbps across my 5.4GHz or 5.7GHz 30/60 or 150/300 Mb OFDM BH link?

Why do I get only 1.5 Mbps across my 5.4GHz or 5.7GHz 30/60 or 150/300 Mb OFDM BH link?

Solution: Disarm the installation agent. During installation the radio modulation is fixed at BPSK 1.5Mbps and TX power is +24dBm