diff --git a/app/build.gradle b/app/build.gradle
index d9638340..d54446df 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -2,11 +2,11 @@ apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
 
 android {
-    compileSdkVersion = 30
+    compileSdkVersion = 31
     defaultConfig {
         applicationId = 'com.tutpro.baresip'
         minSdkVersion 21
-        targetSdkVersion 30
+        targetSdkVersion 31
         versionCode = 182
         versionName = '35.2.0'
         externalNativeBuild {
@@ -54,7 +54,7 @@ dependencies {
     implementation "androidx.swiperefreshlayout:swiperefreshlayout:1.1.0"
     implementation "androidx.preference:preference-ktx:1.1.1"
     implementation "androidx.exifinterface:exifinterface:1.3.3"
-    implementation "androidx.core:core-ktx:1.6.0"
+    implementation "androidx.core:core-ktx:1.7.0"
     implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.4.1'
     implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"
 }
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 9886f1ed..dfb7aa91 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -3,12 +3,14 @@
     xmlns:tools="http://schemas.android.com/tools"
     package="com.tutpro.baresip">
 
+    <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.RECORD_AUDIO" />
     <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
     <uses-permission android:name="android.permission.DISABLE_KEYGUARD" />
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
diff --git a/app/src/main/kotlin/com/tutpro/baresip/BaresipService.kt b/app/src/main/kotlin/com/tutpro/baresip/BaresipService.kt
index 32c31191..f448c815 100644
--- a/app/src/main/kotlin/com/tutpro/baresip/BaresipService.kt
+++ b/app/src/main/kotlin/com/tutpro/baresip/BaresipService.kt
@@ -5,6 +5,7 @@ import android.annotation.SuppressLint
 import android.annotation.TargetApi
 import android.app.*
 import android.bluetooth.BluetoothAdapter
+import android.bluetooth.BluetoothManager
 import android.bluetooth.BluetoothHeadset
 import android.content.*
 import android.media.*
@@ -13,7 +14,6 @@ import android.net.wifi.WifiManager
 import android.os.*
 import android.os.Build.VERSION
 import android.provider.Settings
-import android.telephony.TelephonyManager
 import android.text.Spannable
 import android.text.SpannableString
 import android.text.style.ForegroundColorSpan
@@ -35,6 +35,7 @@ import kotlin.collections.ArrayList
 import kotlin.concurrent.schedule
 import kotlin.math.roundToInt
 import android.media.MediaPlayer
+import android.telecom.TelecomManager
 
 class BaresipService: Service() {
 
@@ -47,7 +48,8 @@ class BaresipService: Service() {
     private lateinit var cm: ConnectivityManager
     private lateinit var pm: PowerManager
     private lateinit var wm: WifiManager
-    private lateinit var tm: TelephonyManager
+    private lateinit var tm: TelecomManager
+    private lateinit var btm: BluetoothManager
     private lateinit var partialWakeLock: PowerManager.WakeLock
     private lateinit var proximityWakeLock: PowerManager.WakeLock
     private lateinit var wifiLock: WifiManager.WifiLock
@@ -58,7 +60,7 @@ class BaresipService: Service() {
     private var audioFocusRequest: AudioFocusRequest? = null
     private var audioFocusUsage = -1
     private var origVolume = mutableMapOf<Int, Int>()
-    private val btAdapter = BluetoothAdapter.getDefaultAdapter()
+    private var btAdapter: BluetoothAdapter? = null
     private var linkAddresses = mutableMapOf<String, String>()
     private var activeNetwork: Network? = null
     private var hotSpotIsEnabled = false
@@ -195,7 +197,10 @@ class BaresipService: Service() {
         this.registerReceiver(hotSpotReceiver,
             IntentFilter("android.net.wifi.WIFI_AP_STATE_CHANGED"))
 
-        tm = getSystemService(Context.TELEPHONY_SERVICE) as TelephonyManager
+        tm = getSystemService(Context.TELECOM_SERVICE) as TelecomManager
+
+        btm = getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
+        btAdapter = btm.adapter
 
         proximityWakeLock = pm.newWakeLock(PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK,
                 "com.tutpro.baresip:proximity_wakelog")
@@ -556,10 +561,10 @@ class BaresipService: Service() {
                     }
                     "call incoming" -> {
                         val peerUri = Api.call_peeruri(callp)
-                        if ((Call.calls().size > 0) ||
-                                (tm.callState != TelephonyManager.CALL_STATE_IDLE) ||
-                                !Utils.checkPermission(applicationContext,
-                                        Manifest.permission.RECORD_AUDIO)) {
+                        if (Call.calls().size > 0 ||
+                            (Utils.checkPermission(this, Manifest.permission.READ_PHONE_STATE) &&
+                                tm.isInCall) ||
+                            !Utils.checkPermission(applicationContext, Manifest.permission.RECORD_AUDIO)) {
                             Log.d(TAG, "Auto-rejecting incoming call $uap/$callp/$peerUri")
                             Api.ua_hangup(uap, callp, 486, "Busy Here")
                             if (ua.account.callHistory) {
@@ -1090,8 +1095,8 @@ class BaresipService: Service() {
     }
 
     private fun isBluetoothHeadsetConnected(): Boolean {
-        return (btAdapter != null) && btAdapter.isEnabled &&
-                (btAdapter.getProfileConnectionState(BluetoothHeadset.HEADSET) ==
+        return (btAdapter != null) && btAdapter!!.isEnabled &&
+                (btAdapter!!.getProfileConnectionState(BluetoothHeadset.HEADSET) ==
                         BluetoothHeadset.STATE_CONNECTED)
     }