Introduce getRssi() in CellSignalStrengthLte
Previous people designed that the lte signal strength from HAL is rssi
in ASU, but the new need of getRssi() API requires dBm unit.
Bug: 113074174
Test: Treehugger
Change-Id: I2982365a2e7fe1a56a393d123b9b0a30807d4d15
diff --git a/api/current.txt b/api/current.txt
index f1700f2..2995d40 100755
--- a/api/current.txt
+++ b/api/current.txt
@@ -42281,6 +42281,7 @@
method public int getLevel();
method public int getRsrp();
method public int getRsrq();
+ method public int getRssi();
method public int getRssnr();
method public int getTimingAdvance();
method public void writeToParcel(android.os.Parcel, int);
diff --git a/telephony/java/android/telephony/CellSignalStrengthLte.java b/telephony/java/android/telephony/CellSignalStrengthLte.java
index d6856b3..280a8d2 100644
--- a/telephony/java/android/telephony/CellSignalStrengthLte.java
+++ b/telephony/java/android/telephony/CellSignalStrengthLte.java
@@ -31,6 +31,25 @@
private static final String LOG_TAG = "CellSignalStrengthLte";
private static final boolean DBG = false;
+ /**
+ * Indicates the unknown or undetectable RSSI value in ASU.
+ *
+ * Reference: TS 27.007 8.5 - Signal quality +CSQ
+ */
+ private static final int SIGNAL_STRENGTH_LTE_RSSI_ASU_UNKNOWN = 99;
+ /**
+ * Indicates the maximum valid RSSI value in ASU.
+ *
+ * Reference: TS 27.007 8.5 - Signal quality +CSQ
+ */
+ private static final int SIGNAL_STRENGTH_LTE_RSSI_VALID_ASU_MAX_VALUE = 31;
+ /**
+ * Indicates the minimum valid RSSI value in ASU.
+ *
+ * Reference: TS 27.007 8.5 - Signal quality +CSQ
+ */
+ private static final int SIGNAL_STRENGTH_LTE_RSSI_VALID_ASU_MIN_VALUE = 0;
+
@UnsupportedAppUsage
private int mSignalStrength;
@UnsupportedAppUsage
@@ -142,6 +161,19 @@
}
/**
+ * Get Received Signal Strength Indication (RSSI) in dBm
+ *
+ * The value range is [-113, -51] inclusively or {@link CellInfo#UNAVAILABLE} if unavailable.
+ *
+ * Reference: TS 27.007 8.5 Signal quality +CSQ
+ *
+ * @return the RSSI if available or {@link CellInfo#UNAVAILABLE} if unavailable.
+ */
+ public int getRssi() {
+ return convertRssiAsuToDBm(mSignalStrength);
+ }
+
+ /**
* Get reference signal signal-to-noise ratio
*
* @return the RSSNR if available or
@@ -309,4 +341,17 @@
private static void log(String s) {
Rlog.w(LOG_TAG, s);
}
+
+ private static int convertRssiAsuToDBm(int rssiAsu) {
+ if (rssiAsu != SIGNAL_STRENGTH_LTE_RSSI_ASU_UNKNOWN
+ && (rssiAsu < SIGNAL_STRENGTH_LTE_RSSI_VALID_ASU_MIN_VALUE
+ || rssiAsu > SIGNAL_STRENGTH_LTE_RSSI_VALID_ASU_MAX_VALUE)) {
+ Rlog.e(LOG_TAG, "convertRssiAsuToDBm: invalid RSSI in ASU=" + rssiAsu);
+ return CellInfo.UNAVAILABLE;
+ }
+ if (rssiAsu == SIGNAL_STRENGTH_LTE_RSSI_ASU_UNKNOWN) {
+ return CellInfo.UNAVAILABLE;
+ }
+ return -113 + (2 * rssiAsu);
+ }
}