Android Signal Strength calculation method

How GSM is calculated:

A: This is GSM, whether the LTE should be different.

ASU conversion to dbm:dbm=-113+ (2*asu)

All

* Get the GSM Signal strength, valid values is (0-31) as defined in TS

* 27.007 8.5

if (ASU <= 2 | | asu = =) level = Signal_strength_none_or_unknown (0);

else if (ASU >=) level = Signal_strength_great (4);

else if (ASU >= 8) level = Signal_strength_good (3);

else if (ASU >= 5) level = Signal_strength_moderate (2);

else level = Signal_strength_poor (1);

Lte:

The LTE calculation method seems to be related to signal to noise ratio and reception quality, details as follows, (Signalstrength.java)

There are also CDMA in this file.

/*

* TS 36.214 physical Layer section 5.1.3 ts 36.331 RRC RSSI = Received

* signal + noise RSRP = Reference signal dBm RSRQ = quality of signal

* db= number of Resource blocksxrsrp/rssi SNR = gain=signal/noise ratio

* = -10log p1/p2 DB

*/

int rssiiconlevel = Signal_strength_none_or_unknown, Rsrpiconlevel =-1, snriconlevel =-1;

if (Mltersrp > -44) rsrpiconlevel =-1;

else if (MLTERSRP >= -85) rsrpiconlevel = signal_strength_great;

else if (MLTERSRP >= -95) rsrpiconlevel = Signal_strength_good;

else if (MLTERSRP >= -105) rsrpiconlevel = signal_strength_moderate;

else if (MLTERSRP >= -115) rsrpiconlevel = Signal_strength_poor;

else if (MLTERSRP >= -140) rsrpiconlevel = Signal_strength_none_or_unknown;

/*

* Values are-200 db to +300 (snr*10db) Rs_snr >= 13.0 DB =>4 bars 4.5

* DB <= Rs_snr < 13.0 db = 3 Bars 1.0 db <= Rs_snr < 4.5 db = 2 bars

* -3.0 db <= Rs_snr < 1.0 db 1 bar Rs_snr < -3.0 db/no Service antenna

* Icon only

*/

if (Mlterssnr >) snriconlevel =-1;

else if (Mlterssnr >=) snriconlevel = signal_strength_great;

else if (Mlterssnr >=) snriconlevel = Signal_strength_good;

else if (Mlterssnr >=) snriconlevel = signal_strength_moderate;

else if (Mlterssnr >= -30) snriconlevel = Signal_strength_poor;

else if (Mlterssnr >=-200)

Snriconlevel = Signal_strength_none_or_unknown;

if (DBG) log ("GETLTELEVEL-RSRP:" + MLTERSRP + "Snr:" + Mlterssnr + "Rsrpiconlevel:"

+ Rsrpiconlevel + "Snriconlevel:" + snriconlevel);

/* Choose a measurement type to use for notification */

if (snriconlevel! =-1 && rsrpiconlevel! =-1) {

/*

* The number of bars displayed shall be the smaller of the bars

* Associated with LTE RSRP and the bars associated with the LTE

* Rs_snr

*/

Return (Rsrpiconlevel < snriconlevel rsrpiconlevel:snriconlevel);

}

if (snriconlevel! =-1) return snriconlevel;

if (rsrpiconlevel! =-1) return rsrpiconlevel;

/* Valid values is (0-63) as defined in TS 36.331 */

if (Mltesignalstrength > Rssiiconlevel) = Signal_strength_none_or_unknown;

else if (mltesignalstrength >=) rssiiconlevel = signal_strength_great;

else if (mltesignalstrength >= 8) rssiiconlevel = Signal_strength_good;

else if (mltesignalstrength >= 5) rssiiconlevel = Signal_strength_moderate;

else if (mltesignalstrength >= 0) rssiiconlevel = Signal_strength_poor;

if (DBG) log ("Getltelevel-rssi:" + mltesignalstrength + "Rssiiconlevel:"

+ Rssiiconlevel);

return rssiiconlevel;

How TD-SCDMA is calculated:

Framework/base/signalstrength.java

public int Gettdscdmalevel () {

Final int tdscdmadbm = GETTDSCDMADBM ();

int level;

if ((tdscdmadbm >-25) | | (tdscdmadbm = = Signalstrength.invalid))

level = Signal_strength_none_or_unknown;

else if (tdscdmadbm >= -49) level = Signal_strength_great;

else if (tdscdmadbm >= -73) level = Signal_strength_good;

else if (tdscdmadbm >= -97) level = Signal_strength_moderate;

else if (tdscdmadbm >= -120) level = Signal_strength_poor;

else level = Signal_strength_none_or_unknown;

if (DBG) log ("Gettdscdmalevel =" + level);

return level;

}

Android Signal Strength calculation method