Channel power measures the average time domain power within the selected bandwidth and is expressed in dBm. Received Signal Strength Indicator (RSSI) is vendor‑defined in the standard and is typically the same as Channel Power.
The difference between the measured carrier frequency and the specified carrier frequency is the frequency error. This number is only as accurate as the frequency reference that is used. Frequency error is displayed in both Hz and ppm. Option 31 (GPS Receiver) can be used for improved frequency accuracy when an external reference is not available at a BTS.
Relative Constellation Error is similar to EVM but is expressed in dB (RCE = 20 log (EVM) where EVM is expressed in % ⁄ 100) Both rms and peak values over an entire downlink subframe are displayed.
Carrier Frequency is the measured frequency of the input signal after demodulation, and is the same as the tuned Center Frequency of the instrument plus the measured Frequency Error from demodulation.
Each transmitter has a unique ID of 48 bits. These instruments display the ID as Base Station ID by decoding the FCH (Frame Control Header), the lower significant bits (LSB) of 4 bits of the downlink frame.
