diff --git a/thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java b/thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java
index 7c757c0..0559499 100644
--- a/thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java
+++ b/thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java
@@ -161,6 +161,9 @@
     // Note that this regex allows "XX:XX-XX" as well but we don't need to be a strict checker
     private static final String OUI_REGEX = "^([0-9A-Fa-f]{2}[:-]?){2}([0-9A-Fa-f]{2})$";
 
+    // The channel mask that indicates all channels from channel 11 to channel 24
+    private static final int CHANNEL_MASK_11_TO_24 = 0x1FFF800;
+
     // Below member fields can be accessed from both the binder and handler threads
 
     private final Context mContext;
@@ -790,6 +793,14 @@
 
     private static int selectChannel(
             int supportedChannelMask, int preferredChannelMask, Random random) {
+        // Due to radio hardware performance reasons, many Thread radio chips need to reduce their
+        // transmit power on edge channels to pass regulatory RF certification. Thread edge channel
+        // 25 and 26 are not preferred here.
+        //
+        // If users want to use channel 25 or 26, they can change the channel via the method
+        // ActiveOperationalDataset.Builder(activeOperationalDataset).setChannel(channel).build().
+        preferredChannelMask = preferredChannelMask & CHANNEL_MASK_11_TO_24;
+
         // If the preferred channel mask is not empty, select a random channel from it, otherwise
         // choose one from the supported channel mask.
         preferredChannelMask = preferredChannelMask & supportedChannelMask;
diff --git a/thread/tests/unit/src/com/android/server/thread/ThreadNetworkControllerServiceTest.java b/thread/tests/unit/src/com/android/server/thread/ThreadNetworkControllerServiceTest.java
index 85b6873..493058f 100644
--- a/thread/tests/unit/src/com/android/server/thread/ThreadNetworkControllerServiceTest.java
+++ b/thread/tests/unit/src/com/android/server/thread/ThreadNetworkControllerServiceTest.java
@@ -115,7 +115,11 @@
     private static final String DEFAULT_NETWORK_NAME = "thread-wpan0";
     private static final int OT_ERROR_NONE = 0;
     private static final int DEFAULT_SUPPORTED_CHANNEL_MASK = 0x07FFF800; // from channel 11 to 26
-    private static final int DEFAULT_PREFERRED_CHANNEL_MASK = 0x00000800; // channel 11
+
+    // The DEFAULT_PREFERRED_CHANNEL_MASK is the ot-daemon preferred channel mask. Channel 25 and
+    // 26 are not preferred by dataset. The ThreadNetworkControllerService will only select channel
+    // 11 when it creates randomized dataset.
+    private static final int DEFAULT_PREFERRED_CHANNEL_MASK = 0x06000800; // channel 11, 25 and 26
     private static final int DEFAULT_SELECTED_CHANNEL = 11;
     private static final byte[] DEFAULT_SUPPORTED_CHANNEL_MASK_ARRAY = base16().decode("001FFFE0");