26
Data Rate (Mbps)
This determines the data rate or the capacity of the PTP link. You can
choose the
Auto
or one of the
MCS
values, which will use a fixed value of RF modulation and
coding. The default value is Auto. The following is choices of MCS values and their
corresponding modulation and coding schemes.
MCS Index
Modulation
Coding
0
BPSK
1/2
1
QPSK
1/2
2
QPSK
3/4
3
16-QAM
1/2
4
16-QAM
3/4
5
64-QAM
2/3
6
64-QAM
3/4
7
64-QAM
5/6
8
256-QAM
3/4
9
256-QAM
5/6
The AUTO setting above will enable the
Adaptive Coding and Modulation (ACM)
function in
the network. This feature allows the system to determine the best TX modulation and MIMO
settings based on current RF conditions. At power-up (or reset), the ACM function will begin
operation at the most robust modulation settings (BPSK-1/2). If link conditions warrant, higher
order settings will be tested and selected for use.
The ACM function operates continuously, i.e. – if RF link conditions change, then the
modulation and MIMO settings will respond in order to maximize link capability without
compromising reliability.
The system relies upon user traffic to determine the optimal modulation settings. When ACM is
enabled, user traffic must be available in order to bring link performance up to its maximum
capability.
ACM is a feature that is enabled on a per-radio basis. It is not necessary for both radios to
share the same state ACM enable/disable configuration.
