Some info on the cambium PTP 550 Data Rates
“Downlink Max Rate” specifies the maximum downlink MCS value that the Rate Adapt algorithm will choose.
MCS values range for data from MCS 9 to MCS 1 for one or two Spatial Streams (Single Stream and Dual Stream respectively). A higher MCS value (e.g. MCS 9) carries more data, but requires more link budget / stronger radio signal. Thus, MCS 9 provides the most data, but the least robust link (i.e. greatest chance data can be lost) and MCS 1 provides the least data, but the most robust link (i.e. least change data can be lost).
DS MCS provide two streams of independent data over the two transmit chains while SS MCS provide one stream of data over both transmit chains.
Setting “Uplink Max Rate” to a DS MCS 9 – DS MCS 1 value will allow this MCS and all lower dual stream MCS values to be used along with all similar or lower single stream MCS values. For example, choosing DS MCS 8 means that DS MCS 8 – DS MCS 1 and SS MCS 8 – SS MCS 1 will be used in the Rate Adapt algorithm. Setting “Uplink Max Rate” to an SS MCS 7 – SS MCS 1 value will allow this and all lower single stream MCS values.
Rates Highest to lowest
DS MCS9 – 256-QAM 5/6
DS MCS8 – 256-QAM 3/4
DS MCS7 – 64-QAM 5/6
DS MCS6 – 64-QAM 3/4
DS MCS5 – 64-QAM 2/3
DS MCS4 – 16-QAM 3/4
DS MCS3 – 16-QAM 3/4
DS MCS2 – QPSK 3/4
DS MCS1 – QPSK 1/2
SS MCS9 – 256-QAM 5/6
SS MCS8 – 256-QAM 3/4
SS MCS7 – 64-QAM 5/6
SS MCS6 – 64-QAM 3/4
SS MCS5 – 64 QAM 2/3
SS MCS4 – 16-QAM-3/4
SS MCS3 – 16-QAM 1/2
SS MCS2- QPSk3/4
SS MCS1 – QPSK 1/2
MCS\Rx Sensitivity 20 MHz 40 MHz 80 MHz
Lowest MCS -90 dBm -87 dBm -83 dBm
Highest MCS . -66 dBm -62 dBm -59 dBm
