So, anyway, the idle band interference shows the level of the noise on the frequencies of the cell.
idle band 1 means that the noise is between x dBm and x dBm
idle band 2, btw x dBm and x dBm, etc
check the properties of the counters to know what are the values of “x”.
If most of the noise is between -47dBm and -70dBm for example, it means there are a lot of interference
If the noise is mostly between -100 and -110dBm, then it means there is no interference (noise is very weeak).
These measurements are done in uplink only, it reflects the uplink noise (heard by the BTS)