diff --git a/.obsidian/workspace b/.obsidian/workspace
index 7f08798..7cc50d7 100644
--- a/.obsidian/workspace
+++ b/.obsidian/workspace
@@ -88,14 +88,14 @@
   "active": "bc6e8ad9aa0f44c3",
   "lastOpenFiles": [
     "School/Analyse/Layers/1. Physical Layer.md",
+    "School/Analyse/Comminucation Mediums.md",
+    "School/Analyse/Images/modulation-frequency.png",
     "School/Analyse/Images/modulation-amplitude.png",
     "School/Analyse/Images/encoder.png",
     "School/Analyse/Network Types.md",
     "School/Analyse/Layers/5. Session Layer.md",
     "School/Analyse/Layers/6. Presentation Layer.md",
     "School/Analyse/Layers/7. Application Layer.md",
-    "School/Analyse/Layers/4. Transport Layer.md",
-    "School/Analyse/Layers/3. Network Layer.md",
-    "School/Analyse/Layers/2. Datalink Layer.md"
+    "School/Analyse/Layers/4. Transport Layer.md"
   ]
 }
\ No newline at end of file
diff --git a/School/Analyse/Images/modulation-frequency.png b/School/Analyse/Images/modulation-frequency.png
new file mode 100644
index 0000000..ddab3b1
Binary files /dev/null and b/School/Analyse/Images/modulation-frequency.png differ
diff --git a/School/Analyse/Layers/1. Physical Layer.md b/School/Analyse/Layers/1. Physical Layer.md
index a187b0b..71ebbe7 100644
--- a/School/Analyse/Layers/1. Physical Layer.md	
+++ b/School/Analyse/Layers/1. Physical Layer.md	
@@ -37,8 +37,12 @@ This can be done in 3 different ways.
 ![[modulation-amplitude.png]]
 
 Amplitude or the strength (height) of a wave changes over time.
-We can change how much the amplitude is changing over a 
+We can change how much the amplitude is changing in a specific moment in time.
 
 ### Frequency
+![[modulation-frequency.png]]
+
+Frequency can be changed 
+
 
 ### Phase
\ No newline at end of file