android.telephony.NeighboringCellInfo#UNKNOWN_RSSI源码实例Demo

/**
 *  Description:  TODO: add more info
 *
 *  Issues:
 *
 *      [ ]     Getting and comparing signal strengths between different RATs can be very
 *              tricky, since they all return different ranges of values. AOS doesn't
 *              specify very clearly what exactly is returned, even though people have
 *              a good idea, by trial and error.
 *
 *              See note in : SignalStrengthTracker.java
 *
 *  Notes:
 *
 *
 *
 */
public void onSignalStrengthsChanged(SignalStrength signalStrength) {
    // Update Signal Strength
    if (signalStrength.isGsm()) {
        int dbm;
        if (signalStrength.getGsmSignalStrength() <= 2 ||
                signalStrength.getGsmSignalStrength() == NeighboringCellInfo.UNKNOWN_RSSI) {
            // Unknown signal strength, get it another way
            String[] bits = signalStrength.toString().split(" ");
            dbm = Integer.parseInt(bits[9]);
        } else {
            dbm = signalStrength.getGsmSignalStrength();
        }
        mDevice.setSignalDbm(dbm);
    } else {
        int evdoDbm = signalStrength.getEvdoDbm();
        int cdmaDbm = signalStrength.getCdmaDbm();

        // Use lowest signal to be conservative
        mDevice.setSignalDbm((cdmaDbm < evdoDbm) ? cdmaDbm : evdoDbm);
    }
    // Send it to signal tracker
    signalStrengthTracker.registerSignalStrength(mDevice.mCell.getCID(), mDevice.getSignalDBm());
    //signalStrengthTracker.isMysterious(mDevice.mCell.getCID(), mDevice.getSignalDBm());
}
 

private void updateGsm(Cell cell, int asu) {
    Timber.d("update(): Updating GSM signal strength = %s", asu);
    if (asu == NeighboringCellInfo.UNKNOWN_RSSI)
        asu = Cell.UNKNOWN_SIGNAL;
    // NOTE: for GSM asu is always positive but RSSI negative
    if (asu >= 0)
        cell.setGsmLocationSignal(asu, UnitConverter.convertGsmAsuToDbm(asu));
    else
        cell.setGsmLocationSignal(UnitConverter.convertGsmDbmToAsu(asu), asu);
}
 

private void updateLte(Cell cell, int dbm) {
    Timber.d("update(): Updating LTE signal strength = %s", dbm);
    if (dbm == NeighboringCellInfo.UNKNOWN_RSSI)
        dbm = Cell.UNKNOWN_SIGNAL;
    // NOTE: for LTE asu is always positive but RSRP negative
    if (dbm >= 0)
        cell.setGsmLocationSignal(dbm, UnitConverter.convertLteAsuToDbm(dbm));
    else
        cell.setGsmLocationSignal(UnitConverter.convertLteDbmToAsu(dbm), dbm);
}
 

public static int convertGsmDbmToAsu(int dbm) {
    if (dbm == Cell.UNKNOWN_SIGNAL || dbm == NeighboringCellInfo.UNKNOWN_RSSI)
        return Cell.UNKNOWN_SIGNAL;
    if (dbm <= -113)
        return 0;
    int asu = (dbm + 113) / 2;
    if (asu > 31)
        return 31;
    return asu;
}
 

public static int convertLteAsuToDbm(int asu) {
    if (asu == Cell.UNKNOWN_SIGNAL || asu == NeighboringCellInfo.UNKNOWN_RSSI)
        return Cell.UNKNOWN_SIGNAL;
    if (asu <= 0)
        return -140;
    if (asu >= 97)
        return -43;
    return asu - 140;
}
 

public static int convertLteDbmToAsu(int dbm) {
    if (dbm == Cell.UNKNOWN_SIGNAL || dbm == NeighboringCellInfo.UNKNOWN_RSSI)
        return Cell.UNKNOWN_SIGNAL;
    if (dbm <= -140)
        return 0;
    if (dbm >= -43)
        return 97;
    return dbm + 140;
}
 

public static int convertGsmAsuToDbm(int asu) {
    if (asu == Cell.UNKNOWN_SIGNAL || asu == NeighboringCellInfo.UNKNOWN_RSSI)
        return Cell.UNKNOWN_SIGNAL;
    return 2 * asu - 113;
}