diff --git a/.gitignore b/.gitignore
index 2b223e4..55dbf60 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,6 +7,7 @@
 /.idea/workspace.xml
 /.idea/navEditor.xml
 /.idea/assetWizardSettings.xml
+/.idea/runConfigurations.xml
 .DS_Store
 /build
 /captures
diff --git a/.idea/deploymentTargetSelector.xml b/.idea/deploymentTargetSelector.xml
new file mode 100644
index 0000000..b268ef3
--- /dev/null
+++ b/.idea/deploymentTargetSelector.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="deploymentTargetSelector">
+    <selectionStates>
+      <SelectionState runConfigName="app">
+        <option name="selectionMode" value="DROPDOWN" />
+      </SelectionState>
+    </selectionStates>
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/gradle.xml b/.idea/gradle.xml
index 0897082..7b3006b 100644
--- a/.idea/gradle.xml
+++ b/.idea/gradle.xml
@@ -4,6 +4,7 @@
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
+        <option name="testRunner" value="CHOOSE_PER_TEST" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
         <option name="gradleJvm" value="#GRADLE_LOCAL_JAVA_HOME" />
         <option name="modules">
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 8978d23..74dd639 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="jbr-17" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="jbr-21" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/apk-builds/app-debug-androidTest.apk b/apk-builds/app-debug-androidTest.apk
new file mode 100644
index 0000000..8188e24
Binary files /dev/null and b/apk-builds/app-debug-androidTest.apk differ
diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 87bd440..c135140 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -29,11 +29,11 @@ android {
         }
     }
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_1_8
-        targetCompatibility = JavaVersion.VERSION_1_8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
     kotlinOptions {
-        jvmTarget = "1.8"
+        jvmTarget = "11"
     }
     buildFeatures {
         viewBinding = true
@@ -87,3 +87,8 @@ dependencies {
     // netmonster
     implementation(libs.netmonster.core)
 }
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+    }
+}
diff --git a/app/src/main/java/eu/bschmidt/devicepublisher/api/celldata/routeCellData.kt b/app/src/main/java/eu/bschmidt/devicepublisher/api/celldata/routeCellData.kt
index 69a96f9..f5d4272 100644
--- a/app/src/main/java/eu/bschmidt/devicepublisher/api/celldata/routeCellData.kt
+++ b/app/src/main/java/eu/bschmidt/devicepublisher/api/celldata/routeCellData.kt
@@ -33,6 +33,12 @@ suspend fun getAvailableCells(viewModel: CellDataViewModel): MutableList<CellDat
     return localCellList
 }
 
+suspend fun getCACells(viewModel: CellDataViewModel): MutableList<CellData> {
+    val localCellList: MutableList<CellData> = mutableListOf<CellData>()
+    localCellList.addAll(viewModel.getCACells().toMutableList())
+    return localCellList
+}
+
 fun Route.routeCellData() {
     val viewModel: CellDataViewModel = CellDataViewModel.getInstance()
     
@@ -75,6 +81,24 @@ fun Route.routeCellData() {
                 }
             }
         }
+
+        route("/estimate-ca") {
+            get("/all") {
+                val cellList = getCACells(viewModel)
+                call.respond(cellList)
+            }
+            get("/cell/{id}") {
+                val id = call.parameters["id"]?.toIntOrNull()
+                val cellList = getCACells(viewModel)
+                if (id != null && id >= 0 && id < cellList.size) {
+                    val someCell: CellData = cellList[id]
+                    call.respond(someCell)
+                } else {
+                    call.respondText("Cell not found", status = HttpStatusCode.NotFound)
+                }
+            }
+        }
+
         
     }
 }
diff --git a/app/src/main/java/eu/bschmidt/devicepublisher/model/celldata/CellDataViewModel.kt b/app/src/main/java/eu/bschmidt/devicepublisher/model/celldata/CellDataViewModel.kt
index 52cb089..4b22cb0 100644
--- a/app/src/main/java/eu/bschmidt/devicepublisher/model/celldata/CellDataViewModel.kt
+++ b/app/src/main/java/eu/bschmidt/devicepublisher/model/celldata/CellDataViewModel.kt
@@ -17,6 +17,7 @@ import cz.mroczis.netmonster.core.model.cell.CellLte
 import cz.mroczis.netmonster.core.model.cell.CellNr
 import cz.mroczis.netmonster.core.model.cell.ICell
 import cz.mroczis.netmonster.core.model.connection.NoneConnection
+import cz.mroczis.netmonster.core.model.connection.PrimaryConnection
 import eu.bschmidt.devicepublisher.MainApplication
 import eu.bschmidt.devicepublisher.model.DataViewModelInterface
 import eu.bschmidt.devicepublisher.util.DevPubUtils
@@ -43,14 +44,15 @@ data class CellData (
     val rssi: Int? = 0,
     val rsrq: Double? = 0.0,
     val rsrp: Double? = 0.0,
-    val estimatedDownBandwidth: Int? = 0,
-    val estimatedUpBandwidth: Int? = 0,
+    var estimatedDownBandwidth: Int? = 0,
+    var estimatedUpBandwidth: Int? = 0,
 )
 
 class CellDataViewModel : ViewModel(), DataViewModelInterface {
 
     private val _coreConnected: MutableList<CellData> = Collections.synchronizedList(mutableListOf<CellData>())
     private val _coreAvailable: MutableList<CellData> = Collections.synchronizedList(mutableListOf<CellData>())
+    private val _coreCA: MutableList<CellData> = Collections.synchronizedList(mutableListOf<CellData>())
 
     private val _connectedCellDataList = MutableLiveData<List<CellData>>()
     val connectedCellDataList: LiveData<List<CellData>> get() = _connectedCellDataList
@@ -58,9 +60,13 @@ class CellDataViewModel : ViewModel(), DataViewModelInterface {
     private val _availableCellDataList = MutableLiveData<List<CellData>>()
     val availableCellDataList: LiveData<List<CellData>> get() = _availableCellDataList
 
+    private val _caCellDataList = MutableLiveData<List<CellData>>()
+    val caCellDataList: LiveData<List<CellData>> get() = _availableCellDataList
+
     init {
         _connectedCellDataList.value = emptyList()
         _availableCellDataList.value = emptyList()
+        _caCellDataList.value = emptyList()
     }
 
     /* connected */
@@ -91,6 +97,20 @@ class CellDataViewModel : ViewModel(), DataViewModelInterface {
         return _coreAvailable.toMutableList()
     }
 
+    /* Carrier Aggregation (CA) */
+
+    private fun setCACellData(newList: List<CellData>) {
+        _coreCA.clear()
+        _coreCA.addAll(newList)
+        DevPubUtils.dispatchToMainThread {
+            _caCellDataList.value = _coreCA
+        }
+    }
+
+    fun getCACells(): List<CellData> {
+        return _coreCA.toMutableList()
+    }
+
     /* logic */
 
     private fun checkPhonePermission(context: Context): Boolean {
@@ -142,6 +162,7 @@ class CellDataViewModel : ViewModel(), DataViewModelInterface {
 
         val conList: MutableList<CellData> = mutableListOf<CellData>()
         val avaList: MutableList<CellData> = mutableListOf<CellData>()
+        val caList: MutableList<CellData> = mutableListOf<CellData>()
 
         currentCells.forEach { cell ->
             if (cell !is CellLte && cell !is CellNr) {
@@ -162,8 +183,8 @@ class CellDataViewModel : ViewModel(), DataViewModelInterface {
                         rssi = lteCell.signal.rssi,
                         rsrp = lteCell.signal.rsrp,
                         rsrq = lteCell.signal.rsrq,
-                        estimatedDownBandwidth = if (cell.connectionStatus != NoneConnection()) down else null,
-                        estimatedUpBandwidth = if (cell.connectionStatus != NoneConnection()) up else null,
+                        estimatedDownBandwidth = null,
+                        estimatedUpBandwidth = null,
                         )
                 }
                 is  CellNr -> {
@@ -179,19 +200,34 @@ class CellDataViewModel : ViewModel(), DataViewModelInterface {
                         rsrp = nrCell.signal.ssRsrp?.toDouble(),
                         rsrq = nrCell.signal.ssRsrq?.toDouble(),
                         frequency = nrCell.band!!.downlinkFrequency,
-                        estimatedDownBandwidth = if (cell.connectionStatus != NoneConnection()) down else null,
-                        estimatedUpBandwidth = if (cell.connectionStatus != NoneConnection()) up else null,
+                        estimatedDownBandwidth = null,
+                        estimatedUpBandwidth = null,
                         )
                 }
             }
-            if (cell.connectionStatus != NoneConnection()) {
+            if (cell.connectionStatus is PrimaryConnection) {
+                cellData.estimatedUpBandwidth = up
+                cellData.estimatedDownBandwidth = down
                 conList.add(cellData)
+                caList.add(cellData)
             } else {
                 avaList.add(cellData)
             }
         }
+        /* If there is one connected cell, take the best-RSRQ cell
+           as an "estimate" to the potential Carrier Aggregation cells
+         */
+        if (caList.size == 1 && avaList.size >= 1) {
+            val lowestRsrqCell = avaList
+                .filter { it.rsrq != null }
+                .maxByOrNull { it.rsrq!! }
+            if (lowestRsrqCell != null) {
+                caList.add(lowestRsrqCell)
+            }
+        }
         setConnectedCellData(conList)
         setAvailableCellData(avaList)
+        setCACellData(caList)
     }
 
     companion object {
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 3240ca9..209c22c 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,5 +1,5 @@
 [versions]
-agp = "8.3.2"
+agp = "8.7.1"
 kotlin = "1.9.22"
 coreKtx = "1.10.1"
 activityCompose = "1.8.2"
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 48d5efc..78c0d4e 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 #Thu Apr 04 23:44:22 CEST 2024
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.9-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 9dbf546..4310ddb 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -11,6 +11,9 @@ pluginManagement {
         gradlePluginPortal()
     }
 }
+plugins {
+    id("org.gradle.toolchains.foojay-resolver-convention") version "0.8.0"
+}
 dependencyResolutionManagement {
     repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
     repositories {