Improve a calculation method for LTE antenna reception level

RSRP value thresholds is relatively high compared with
other mobile phone platforms, which make android seems
low sensitive to radio. This patch sets better thresholds.

Bug: 17891524
Change-Id: I502e1c3d08b2a52c51fe93da9b77476ac827a25b

1 files changed, 22 insertions, 6 deletions

diff --git a/telephony/java/android/telephony/SignalStrength.java b/telephony/java/android/telephony/SignalStrength.java
index 3363ca6..17db3fb 100644
--- a/telephony/java/android/telephony/SignalStrength.java
+++ b/telephony/java/android/telephony/SignalStrength.java
@@ -20,6 +20,7 @@ import android.os.Bundle;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.telephony.Rlog;
+import android.content.res.Resources;
 
 /**
  * Contains phone signal strength related information.
@@ -50,6 +51,11 @@ public class SignalStrength implements Parcelable {
     //Use int max, as -1 is a valid value in signal strength
     public static final int INVALID = 0x7FFFFFFF;
 
+    private static final int RSRP_THRESH_TYPE_STRICT = 0;
+    private static final int[] RSRP_THRESH_STRICT = new int[] {-140, -115, -105, -95, -85, -44};
+    private static final int[] RSRP_THRESH_LENIENT = new int[] {-140, -128, -118, -108, -98, -44};
+
+
     private int mGsmSignalStrength; // Valid values are (0-31, 99) as defined in TS 27.007 8.5
     private int mGsmBitErrorRate;   // bit error rate (0-7, 99) as defined in TS 27.007 8.5
     private int mCdmaDbm;   // This value is the RSSI value
@@ -745,12 +751,21 @@ public class SignalStrength implements Parcelable {
          */
         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;
+        int rsrpThreshType = Resources.getSystem().getInteger(com.android.internal.R.integer.
+                config_LTE_RSRP_threshold_type);
+        int[] threshRsrp;
+        if (rsrpThreshType == RSRP_THRESH_TYPE_STRICT) {
+            threshRsrp = RSRP_THRESH_STRICT;
+        } else {
+            threshRsrp = RSRP_THRESH_LENIENT;
+        }
+
+        if (mLteRsrp > threshRsrp[5]) rsrpIconLevel = -1;
+        else if (mLteRsrp >= threshRsrp[4]) rsrpIconLevel = SIGNAL_STRENGTH_GREAT;
+        else if (mLteRsrp >= threshRsrp[3]) rsrpIconLevel = SIGNAL_STRENGTH_GOOD;
+        else if (mLteRsrp >= threshRsrp[2]) rsrpIconLevel = SIGNAL_STRENGTH_MODERATE;
+        else if (mLteRsrp >= threshRsrp[1]) rsrpIconLevel = SIGNAL_STRENGTH_POOR;
+        else if (mLteRsrp >= threshRsrp[0]) rsrpIconLevel = SIGNAL_STRENGTH_NONE_OR_UNKNOWN;
 
         /*
          * Values are -200 dB to +300 (SNR*10dB) RS_SNR >= 13.0 dB =>4 bars 4.5
@@ -789,6 +804,7 @@ public class SignalStrength implements Parcelable {
         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;