All are indicators of the quality of the received DMR signal
RSSI (Received Signal Strength Indicator) - a negative number -100 dBm is good, -65 is superior and -115 likely is broken
BER (Bit Error Rate) - 0% is best, 3% to 5% can cause significant negative impact to the received audio quality
Loss Rate - Combined RSSI and BER - a CallWatch computation - 0% is best, 3%-5% might be understandable