diff --git a/openair3/CMakeLists.txt b/openair3/CMakeLists.txt
index 555ca7cbc8..f638abbaaa 100644
--- a/openair3/CMakeLists.txt
+++ b/openair3/CMakeLists.txt
@@ -3,3 +3,4 @@ add_subdirectory(M3AP)
 add_subdirectory(S1AP)
 add_subdirectory(NGAP)
 add_subdirectory(NRPPA)
+add_subdirectory(NAS)
diff --git a/openair3/NAS/CMakeLists.txt b/openair3/NAS/CMakeLists.txt
new file mode 100644
index 0000000000..50cbedd280
--- /dev/null
+++ b/openair3/NAS/CMakeLists.txt
@@ -0,0 +1 @@
+add_subdirectory(COMMON)
diff --git a/openair3/NAS/COMMON/CMakeLists.txt b/openair3/NAS/COMMON/CMakeLists.txt
new file mode 100644
index 0000000000..21de73f92f
--- /dev/null
+++ b/openair3/NAS/COMMON/CMakeLists.txt
@@ -0,0 +1,2 @@
+add_subdirectory(IES)
+add_subdirectory(EMM)
diff --git a/openair3/NAS/COMMON/EMM/CMakeLists.txt b/openair3/NAS/COMMON/EMM/CMakeLists.txt
new file mode 100644
index 0000000000..1da5bad152
--- /dev/null
+++ b/openair3/NAS/COMMON/EMM/CMakeLists.txt
@@ -0,0 +1,5 @@
+add_subdirectory(MSG)
+
+if(ENABLE_TESTS)
+  add_subdirectory(tests)
+endif()
diff --git a/openair3/NAS/COMMON/EMM/MSG/CMakeLists.txt b/openair3/NAS/COMMON/EMM/MSG/CMakeLists.txt
new file mode 100644
index 0000000000..fed78e453d
--- /dev/null
+++ b/openair3/NAS/COMMON/EMM/MSG/CMakeLists.txt
@@ -0,0 +1,10 @@
+add_library(fgs_lib OBJECT
+            fgs_service_request.c
+)
+
+target_link_libraries(fgs_lib PUBLIC fgs_ies_lib)
+
+target_include_directories(fgs_lib PUBLIC
+                           ${CMAKE_SOURCE_DIR}
+                           ${CMAKE_CURRENT_SOURCE_DIR}
+)
diff --git a/openair3/NAS/COMMON/EMM/tests/CMakeLists.txt b/openair3/NAS/COMMON/EMM/tests/CMakeLists.txt
new file mode 100644
index 0000000000..3f960c5562
--- /dev/null
+++ b/openair3/NAS/COMMON/EMM/tests/CMakeLists.txt
@@ -0,0 +1,13 @@
+message(STATUS "Add test nas_lib_test")
+
+add_executable(nas_lib_test nas_lib_test.c)
+
+add_dependencies(tests nas_lib_test)
+add_test(NAME nas_lib_test COMMAND nas_lib_test)
+
+target_link_libraries(nas_lib_test PRIVATE fgs_lib fgs_ies_lib)
+
+target_include_directories(nas_lib_test PRIVATE
+    ${CMAKE_SOURCE_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}
+)
diff --git a/openair3/NAS/COMMON/EMM/tests/nas_lib_test.c b/openair3/NAS/COMMON/EMM/tests/nas_lib_test.c
new file mode 100644
index 0000000000..41865051cd
--- /dev/null
+++ b/openair3/NAS/COMMON/EMM/tests/nas_lib_test.c
@@ -0,0 +1,82 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <arpa/inet.h>
+#include "fgs_service_request.h"
+#include "nr_nas_msg.h"
+
+void exit_function(const char *file, const char *function, const int line, const char *s, const int assert)
+{
+  printf("detected error at %s:%d:%s: %s\n", file, line, function, s);
+  abort();
+}
+
+/**
+ * @brief Equality check for NAS Service Request enc/dec
+ */
+static bool eq_service_request(const fgs_service_request_msg_t *a, const fgs_service_request_msg_t *b)
+{
+  bool result = true;
+  result &= memcmp(&a->naskeysetidentifier, &b->naskeysetidentifier, sizeof(NasKeySetIdentifier)) == 0;
+  result &= a->serviceType == b->serviceType;
+  result &= memcmp(&a->fiveg_s_tmsi, &b->fiveg_s_tmsi, sizeof(Stmsi5GSMobileIdentity_t)) == 0;
+  return result;
+}
+
+/**
+ * @brief Test NAS Service Request enc/dec
+ */
+static void test_service_request(void)
+{
+  // Dummy NAS Service Request message
+  uint16_t amf_set_id = 0x48;
+  uint16_t amf_pointer = 0x34;
+  uint32_t tmsi = 0x56789ABC;
+  fgs_service_request_msg_t original_msg = {
+      .naskeysetidentifier = {.tsc = NAS_KEY_SET_IDENTIFIER_NATIVE, .naskeysetidentifier = NAS_KEY_SET_IDENTIFIER_NOT_AVAILABLE},
+      .serviceType = SERVICE_TYPE_DATA,
+      .fiveg_s_tmsi = {.spare = 0,
+                       .typeofidentity = FGS_MOBILE_IDENTITY_5GS_TMSI,
+                       .amfsetid = amf_set_id,
+                       .amfpointer = amf_pointer,
+                       .tmsi = tmsi}};
+
+  uint8_t expected_encoded_data[] = {0x71,
+                                     0x00,
+                                     0x00,
+                                     0xF4,
+                                     (amf_set_id >> 2) & 0xFF,
+                                     (amf_set_id << 6) | (amf_pointer & 0x3F),
+                                     (tmsi >> 24) & 0xFF,
+                                     (tmsi >> 16) & 0xFF,
+                                     (tmsi >> 8) & 0xFF,
+                                     tmsi & 0xFF};
+  uint16_t tmp = htons(7); // length of 5GS mobile identity IE for 5G-S-TMSI (bytes)
+  memcpy(expected_encoded_data + 1, &tmp, sizeof(tmp));
+
+  // Buffer
+  uint8_t buffer[64];
+  memset(buffer, 0, sizeof(buffer));
+
+  // Encode NAS Service Request
+  int encoded_length = encode_fgs_service_request(buffer, &original_msg, sizeof(buffer));
+  AssertFatal(encoded_length >= 0, "encode_fgs_service_request() failed\n");
+
+  // Compare the raw encoded buffer with expected encoded data
+  AssertFatal(memcmp(buffer, expected_encoded_data, encoded_length) == 0, "Encoding mismatch!\n");
+
+  // Decode NAS Service Request
+  fgs_service_request_msg_t decoded_service_request = {0};
+  int decoded_length = decode_fgs_service_request(&decoded_service_request, buffer, sizeof(buffer));
+  AssertFatal(decoded_length >= 0, "decode_fgs_service_request() failed\n");
+
+  // Compare original and decoded messages
+  AssertFatal(eq_service_request(&original_msg, &decoded_service_request) == 0,
+              "test_service_request() failed: original and decoded messages do not match\n");
+}
+
+int main()
+{
+  test_service_request();
+  return 0;
+}
diff --git a/openair3/NAS/COMMON/IES/CMakeLists.txt b/openair3/NAS/COMMON/IES/CMakeLists.txt
new file mode 100644
index 0000000000..99df08e7b0
--- /dev/null
+++ b/openair3/NAS/COMMON/IES/CMakeLists.txt
@@ -0,0 +1,9 @@
+add_library(fgs_ies_lib OBJECT
+            NasKeySetIdentifier.c
+            FGSMobileIdentity.c
+)
+
+target_include_directories(fgs_ies_lib PUBLIC
+                           ${CMAKE_SOURCE_DIR}
+                           ${CMAKE_CURRENT_SOURCE_DIR}
+)