Interpretting the output of dumpsys telephony.registry
From the sources, it looks like it's printing out the contents of the SignalStrength object:


private SignalStrength mSignalStrength = new SignalStrength();

...

        pw.println("last known state:");
        ...
        pw.println("  mSignalStrength=" + mSignalStrength);
        ...



This object is described in detail on the Android Developers reference here.  The string representation of the SignalStrength class is defined here (search for "toString" function):


public String toString() {
    return ("SignalStrength:"
            + " " + mGsmSignalStrength
            + " " + mGsmBitErrorRate
            + " " + mCdmaDbm
            + " " + mCdmaEcio
            + " " + mEvdoDbm
            + " " + mEvdoEcio
            + " " + mEvdoSnr
            + " " + mLteSignalStrength
            + " " + mLteRsrp
            + " " + mLteRsrq
            + " " + mLteRssnr
            + " " + mLteCqi
            + " " + (isGsm ? "gsm|lte" : "cdma"));
}



This basically tells you the columns in the dumpsys output.