Upstream OFDMA Receive MER per Subcarrier is a PNM Test described in [PHYv3.1] Upstream Receive Modulation Error Ratio (RxMER) Per Subcarrier section. The CmtsUsOfdmaRxMerTable defines the management interface for the operator to configure, execute, and monitor the Upstream OFDMA Receive MER per Subcarrier test. This item provides measurements of the upstream receive modulation error ratio (RxMER) for each subcarrier. The CCAP measures the RxMER using an upstream probe, which is not subject to symbol errors as data subcarriers would be. The probes used for RxMER measurement are typically distinct from the probes used for pre-equalization adjustment. For the purposes of this measurement, RxMER is defined as the ratio of the average power of the ideal QAM constellation to the average error-vector power. The error vector is the difference between the equalized received probe value and the known correct probe value. If some subcarriers (such as exclusion bands) cannot be measured by the CCAP, the CCAP indicates that condition in the measurement data for those subcarriers. The CCAP should reject configuring a value for the DestinationIndex of the UsOfdmaRxMerPerSubcarrier object if that value does not exist in the corresponding DestinationIndex attribute of the DataTransferCfg instance. The CCAP may support simultaneous Upstream OFDMA RxMER per Subcarrier tests on more than one OFDMA channel at a time. The CCAP should be capable of selecting a specified transmitting CM for the Upstream OFDMA RxMER per Subcarrier test. The CCAP should provide probe opportunities and make measurements over the number of averages specified for the Upstream OFDMA RxMER per Subcarrier test. The CCAP should create a row in the docsPnmCmtsUsOfdmaRxMerTable for each ifIndex of an upstream channel.