diff --git a/CHANGELOG.md b/CHANGELOG.md
index a201bc4cb3da482d3f5eee3147f9d35da30e567b..e1bd1601e2cb6e7cee343127c9593a1439baf4a9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,64 @@
 # RELEASE NOTES: #
 
+## v1.5.1 -- May 2023 ##
+
+* Tutorials:
+  * All basic-based tutorials are now only in HTTP/2 mode and with NRF
+    - All non-NRF basic deployments have been obsoleted
+* Update the helm charts and helm chart tutorial
+* Testing:
+  * Load tester for 5000 PDU sessions
+* Common features/fixes for all Network Functions:
+  * Code Refactoring for:
+    * Logging mechanism (runtime log level selection)
+    * Installation / build scripts
+    * Continuous Integration scripts
+  * Published images on Docker-Hub is using now Ubuntu-20 as base image
+    * We will soon obsolete the build system for Ubuntu18.04
+* `AMF` changes:
+  * Fix Service Request handling (Service Type: Signalling)
+  * Fix N2 handover
+  * Support usage of SUPI-type IMSI
+  * Fix mapping between RAN UE NGAP ID and UE context
+  * Fix SBI port for UDM in case of FQDN resolution
+  * Fix TMSI handling
+  * Fix PDU Session Ressource Release Response message
+  * Fix issue for decoding MSIN with an odd number of digits
+  * Fix usage of lower-case for DNN value (case insensitive)
+  * Fix: NSSF port number was not read from config file
+  * Code Refactoring for:
+    * NAS layer
+    * Registration Complete Message
+    * UE context refactor
+* `NRF` changes:
+  * Tentative fix for a failed assertion of Boost signal
+  * HTTP2 fix for json response data formatting
+* `PCF` changes:
+  * Add HTTP/2 support
+* `SMF` changes:
+  * Fix N1N2 Content message
+  * Remove ranInfo field in n2infocontainer
+  * Fix encoding NAS header
+  * Resolved QoS Flow info missing in N2 Handover Preparation
+  * Fix SUPI format: Use IMSI as SUPI
+  * Fix: Send PDU Session Reject when PDU session fails before SMF procedure is started
+  * Fix HTTP header
+  * Fixing config parameter read
+  * Fix for IE Redirect Information
+  * Fix: Associate node id based on node id type
+  * Use N3 ip address from NF profile if provided
+  * Fix: UL TEID for multiple created PDR
+  * Fix for encode/decode of create QER IE
+  * Support for DL PDR in session establishment
+  * Use NWI from config file when no UPF profile is associated
+  * Fix HTTP/2 issue with PCF
+* `UDM` changes:
+  * HTTP2 Fix: Removed duplicate request handler
+* `UDR` changes:
+  * Fix PLMN ID for SessionManagementSubscriptionData (HTTP2)
+  * logging: Add UE ID in the log
+  * Retry NF Register if registration failed
+
 ## v1.5.0 -- January 2023 ##
 
 * New tutorials:
diff --git a/docs/LIST_OF_TESTED_COTSUE.md b/docs/LIST_OF_TESTED_COTSUE.md
index 34b23493e92ae9f76b38ed1dce40d4896c0db695..0d1a97a5b076ed5ddde2f2068e8bf908446994c3 100644
--- a/docs/LIST_OF_TESTED_COTSUE.md
+++ b/docs/LIST_OF_TESTED_COTSUE.md
@@ -29,12 +29,12 @@
 |Fritzbox 6850         |                                                          |     |NA                                                                                      |
 
 
-**Sim Cards** 
+**Sim Cards**
 
 - Opencells
 - Symocom SJS1 and SJA2
 
 **Note**:
 
-1. We are having issues with Android 13 we are investigating and trying to resolve them 
+1. We are having issues with Android 13 we are investigating and trying to resolve them.
 2. We have issues with Anritsu Test UICC TM P0551A sim cards because they sent concealed SUCI which is not yet implemented.