Android: NeighboringCellInfo.getRssi () returns weird data for UMTS cells

According to Android developer documentation, it is NeighboringCellInfo.getRssi()

stated as follows:

received signal strength or UNKNOWN_RSSI if unknown. For GSM, it is in "asu" ranging from 0 to 31 (dBm = -113 + 2 * asu) 0 means "-113 dBm or less" and 31 means "-51 dBm or more". For UMTS, this is the CPICH RSCP level index defined in TS 25.125

Some research has found that this is probably a typo and actually refers to TS.1.1.1.3 section of TS 25.133 ( http://www.3gpp.org/DynaReport/25133.htm ). Version 10.2.0 this document essentially states that CPICH_RSCP_LEV_-04

corresponds -120 dBm <= CPICH RSCP < -119 dBm

, etc. Therefore, the signal level in dBm is obtained by subtracting 116 from the message level.

The reporting range is -120 to -25 dBm, which corresponds to levels from -5 to +91.

In practice, however, I notice that the return values ​​are outside this range. I see getRssi()

return values ​​around -100. I suspect the function is not returning levels as stated in the doc, but dBm .

Does anyone else come across this and can confirm that Android is indeed returning dBm and not signal strength? Or is it a problem with the device used in the tests (OnePlus One runs Cyanogenmod 11 m11 - the community version, not the spare Cyanogenmod 11S that the phone comes with)?