diff --git a/lib/include/srsran/interfaces/ue_nas_interfaces.h b/lib/include/srsran/interfaces/ue_nas_interfaces.h
index fa7f0f47d..e9fe56f43 100644
--- a/lib/include/srsran/interfaces/ue_nas_interfaces.h
+++ b/lib/include/srsran/interfaces/ue_nas_interfaces.h
@@ -39,6 +39,17 @@ public:
   virtual bool     connection_request_completed(bool outcome)                                            = 0;
 };
 
+class nas_5g_interface_rrc_nr
+{
+public:
+};
+
+class nas_5g_interface_procedures
+{
+public:
+  virtual int send_registration_request() = 0;
+};
+
 } // namespace srsue
 
 #endif // SRSRAN_UE_NAS_INTERFACES_H
diff --git a/lib/include/srsran/interfaces/ue_rrc_interfaces.h b/lib/include/srsran/interfaces/ue_rrc_interfaces.h
index 96071af1d..ca1ded8a8 100644
--- a/lib/include/srsran/interfaces/ue_rrc_interfaces.h
+++ b/lib/include/srsran/interfaces/ue_rrc_interfaces.h
@@ -113,6 +113,10 @@ public:
   virtual bool is_config_pending()                                               = 0;
 };
 
+class rrc_nr_interface_nas_5g
+{
+public:
+};
 } // namespace srsue
 
 #endif // SRSRAN_UE_RRC_INTERFACES_H
diff --git a/srsue/hdr/stack/upper/nas_5g.h b/srsue/hdr/stack/upper/nas_5g.h
new file mode 100644
index 000000000..34171d605
--- /dev/null
+++ b/srsue/hdr/stack/upper/nas_5g.h
@@ -0,0 +1,98 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSUE_NAS_5G_H
+#define SRSUE_NAS_5G_H
+
+#include "nas_base.h"
+#include "srsran/common/buffer_pool.h"
+#include "srsran/common/common.h"
+#include "srsran/common/nas_pcap.h"
+#include "srsran/common/security.h"
+#include "srsran/common/stack_procedure.h"
+#include "srsran/common/task_scheduler.h"
+#include "srsran/interfaces/ue_gw_interfaces.h"
+#include "srsran/interfaces/ue_nas_interfaces.h"
+#include "srsran/interfaces/ue_rrc_interfaces.h"
+#include "srsran/interfaces/ue_usim_interfaces.h"
+#include "srsran/srslog/srslog.h"
+#include "srsue/hdr/stack/upper/nas_5gmm_state.h"
+#include "srsue/hdr/stack/upper/nas_config.h"
+
+using srsran::byte_buffer_t;
+
+namespace srsue {
+
+class nas_5g : public nas_base, public nas_5g_interface_rrc_nr, public nas_5g_interface_procedures
+{
+public:
+  explicit nas_5g(srsran::task_sched_handle task_sched_);
+  virtual ~nas_5g();
+  int  init(usim_interface_nas* usim_, rrc_nr_interface_nas_5g* rrc_nr_, gw_interface_nas* gw_, const nas_args_t& cfg_);
+  void stop();
+  void run_tti();
+
+  // Stack+RRC interface
+  bool is_registered();
+
+  // timer callback
+  void timer_expired(uint32_t timeout_id);
+
+  // Stack interface
+  int switch_on();
+  int switch_off();
+  int enable_data();
+  int disable_data();
+  int start_service_request();
+
+private:
+  rrc_nr_interface_nas_5g* rrc_nr = nullptr;
+  usim_interface_nas*      usim   = nullptr;
+  gw_interface_nas*        gw     = nullptr;
+
+  bool running = false;
+
+  nas_args_t   cfg   = {};
+  mm5g_state_t state = {};
+
+  // Security
+  bool ia5g_caps[8] = {};
+  bool ea5g_caps[8] = {};
+
+  // timers
+  srsran::task_sched_handle           task_sched;
+  srsran::timer_handler::unique_timer t3502; // started when registration failure and the attempt counter is equal to 5
+  srsran::timer_handler::unique_timer t3510; // started when transmission of REGISTRATION REQUEST message. ON EXPIRY:
+                                             // start T3511 or T3502 as specified in subclause 5.5.1.2.7
+  srsran::timer_handler::unique_timer t3511; // started when registration failure due to lower layer failure
+  srsran::timer_handler::unique_timer t3521; // started when detach request is sent
+  srsran::timer_handler::unique_timer reregistration_timer; // started to trigger delayed re-attach
+
+  // Values according to TS 24.501 Sec 10.2
+  const uint32_t t3502_duration_ms                = 12 * 60 * 1000; // 12m
+  const uint32_t t3510_duration_ms                = 15 * 1000;      // 15s
+  const uint32_t t3511_duration_ms                = 10 * 1000;      // 10s
+  const uint32_t t3521_duration_ms                = 15 * 1000;      // 15s
+  const uint32_t reregistration_timer_duration_ms = 2 * 1000;       // 2s (arbitrarily chosen to delay re-attach)
+
+  srsran::proc_manager_list_t callbacks;
+
+  // Procedures
+  // Forward declartion
+  class registration_procedure;
+
+  srsran::proc_t<registration_procedure> registration_proc;
+
+  int send_registration_request();
+};
+} // namespace srsue
+#endif
\ No newline at end of file
diff --git a/srsue/hdr/stack/upper/nas_5g_procedures.h b/srsue/hdr/stack/upper/nas_5g_procedures.h
new file mode 100644
index 000000000..85ef15bcd
--- /dev/null
+++ b/srsue/hdr/stack/upper/nas_5g_procedures.h
@@ -0,0 +1,40 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSUE_NAS_5G_PROCEDURES_H_
+#define SRSUE_NAS_5G_PROCEDURES_H_
+
+#include "srsue/hdr/stack/upper/nas_5g.h"
+
+namespace srsue {
+
+/**
+ * @brief 5G NAS registration procedure
+ *
+ * Specified in 24 501 V16.7.0
+ * 5GMM specific procedures
+ * 5.5.1 Registration procedure
+ */
+class nas_5g::registration_procedure
+{
+public:
+  explicit registration_procedure(nas_5g_interface_procedures* parent_nas_);
+  srsran::proc_outcome_t init();
+  srsran::proc_outcome_t step();
+  static const char*     name() { return "Registration Procedure"; }
+
+private:
+  nas_5g_interface_procedures* parent_nas;
+};
+} // namespace srsue
+
+#endif // SRSUE_NAS_5G_PROCEDURES_H_
\ No newline at end of file
diff --git a/srsue/hdr/stack/upper/nas_5gmm_state.h b/srsue/hdr/stack/upper/nas_5gmm_state.h
new file mode 100644
index 000000000..29fb2a983
--- /dev/null
+++ b/srsue/hdr/stack/upper/nas_5gmm_state.h
@@ -0,0 +1,88 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#ifndef SRSUE_NR_NAS_MM5G_STATE_H
+#define SRSUE_NR_NAS_MM5G_STATE_H
+
+#include "srsran/srslog/srslog.h"
+#include <atomic>
+#include <string>
+
+namespace srsue {
+
+// 5GMM states (3GPP 24.501 v16.07.0)
+class mm5g_state_t
+{
+public:
+  enum class state_t {
+    null = 0,
+    deregistered,
+    registered_initiated,
+    registered,
+    deregistered_initiated,
+    service_request_initiated,
+  };
+
+  // 5GMM-DEREGISTERED sub-states (3GPP 24.501 v16.07.0)
+  enum class deregistered_substate_t {
+    null = 0, // This should be used when not in mm5g-DEREGISTERED
+    normal_service,
+    limited_service,
+    attempting_to_registration,
+    plmn_search,
+    no_supi,
+    no_cell_available,
+    e_call_inactive,
+    initial_registration_needed,
+  };
+
+  // 5GMM-DEREGISTERED sub-states (3GPP 24.501 v16.07.0)
+  enum class registered_substate_t {
+    null = 0, // This should be used when not in mm5g-REGISTERED
+    normal_service,
+    non_allowed_service,
+    attempting_registration_update,
+    limited_service,
+    plmn_search,
+    no_cell_available,
+    update_needed,
+  };
+
+  // FSM setters
+  void set_null();
+  void set_deregistered(deregistered_substate_t substate);
+  void set_deregistered_initiated();
+  void set_registered(registered_substate_t substate);
+  void set_registered_initiated();
+  void set_service_request_initiated();
+
+  // FSM getters
+  state_t                 get_state() { return state; }
+  deregistered_substate_t get_deregistered_substate() { return deregistered_substate; }
+  registered_substate_t   get_registered_substate() { return registered_substate; }
+
+  // Text Helpers
+  const std::string get_full_state_text();
+
+private:
+  std::atomic<state_t>    state{state_t::null};
+  deregistered_substate_t deregistered_substate = deregistered_substate_t::null;
+  registered_substate_t   registered_substate   = registered_substate_t::null;
+  srslog::basic_logger&   logger                = srslog::fetch_basic_logger("NAS-5G");
+};
+
+const char* mm5g_state_text(mm5g_state_t::state_t type);
+const char* mm5g_deregistered_substate_text(mm5g_state_t::deregistered_substate_t type);
+const char* mm5g_registered_substate_text(mm5g_state_t::registered_substate_t type);
+
+} // namespace srsue
+#endif
diff --git a/srsue/hdr/stack/upper/nas_config.h b/srsue/hdr/stack/upper/nas_config.h
index 1836b7fce..179b0f7fa 100644
--- a/srsue/hdr/stack/upper/nas_config.h
+++ b/srsue/hdr/stack/upper/nas_config.h
@@ -34,6 +34,8 @@ public:
   bool           force_imsi_attach;
   std::string    eia;
   std::string    eea;
+  std::string    ia5g;
+  std::string    ea5g;
   nas_sim_args_t sim;
 };
 
diff --git a/srsue/hdr/stack/upper/test/nas_test_common.h b/srsue/hdr/stack/upper/test/nas_test_common.h
index 1af31d3c7..faa40bf51 100644
--- a/srsue/hdr/stack/upper/test/nas_test_common.h
+++ b/srsue/hdr/stack/upper/test/nas_test_common.h
@@ -22,6 +22,7 @@
 #include "srsran/test/ue_test_interfaces.h"
 #include "srsue/hdr/stack/upper/gw.h"
 #include "srsue/hdr/stack/upper/nas.h"
+#include "srsue/hdr/stack/upper/nas_5g.h"
 #include "srsue/hdr/stack/upper/usim.h"
 #include "srsue/hdr/stack/upper/usim_base.h"
 
@@ -122,6 +123,26 @@ private:
   bool                            is_connected_flag = false;
 };
 
+class rrc_nr_dummy : public rrc_nr_interface_nas_5g
+{
+public:
+  rrc_nr_dummy() : last_sdu_len(0)
+  {
+    plmns[0].plmn_id.from_number(mcc, mnc);
+    plmns[0].tac = 0xffff;
+  }
+  void init(nas_5g* nas_5g_) { nas_5g_ptr = nas_5g_; }
+  void write_sdu(unique_byte_buffer_t sdu)
+  {
+    last_sdu_len = sdu->N_bytes;
+    // printf("NAS generated SDU (len=%d):\n", sdu->N_bytes);
+  }
+
+private:
+  nas_5g*                         nas_5g_ptr;
+  uint32_t                        last_sdu_len;
+  nas_interface_rrc::found_plmn_t plmns[nas_interface_rrc::MAX_FOUND_PLMNS];
+};
 template <typename T>
 class test_stack_dummy : public srsue::stack_test_dummy, public stack_interface_gw, public thread
 {
@@ -132,7 +153,11 @@ public:
     nas = nas_;
     start(-1);
   }
-  bool switch_on() { nas->switch_on(); return true; }
+  bool switch_on()
+  {
+    nas->switch_on();
+    return true;
+  }
   void write_sdu(uint32_t lcid, srsran::unique_byte_buffer_t sdu) { pdcp->write_sdu(lcid, std::move(sdu)); }
   bool has_active_radio_bearer(uint32_t eps_bearer_id) { return true; }
 
@@ -158,7 +183,7 @@ public:
     wait_thread_finish();
   }
   pdcp_interface_stack* pdcp    = nullptr;
-  T*           nas     = nullptr;
+  T*                    nas     = nullptr;
   std::atomic<bool>     running = {false};
 };
 
diff --git a/srsue/src/stack/upper/CMakeLists.txt b/srsue/src/stack/upper/CMakeLists.txt
index 4d9f1e09f..29c26f205 100644
--- a/srsue/src/stack/upper/CMakeLists.txt
+++ b/srsue/src/stack/upper/CMakeLists.txt
@@ -8,7 +8,7 @@
 
 add_subdirectory(test)
 
-set(SOURCES nas.cc nas_emm_state.cc nas_idle_procedures.cc gw.cc usim_base.cc usim.cc tft_packet_filter.cc nas_base.cc)
+set(SOURCES nas.cc nas_emm_state.cc nas_idle_procedures.cc gw.cc usim_base.cc usim.cc tft_packet_filter.cc nas_base.cc nas_5g_procedures.cc nas_5g.cc nas_5gmm_state.cc)
 
 if(HAVE_PCSC)
   list(APPEND SOURCES "pcsc_usim.cc")
@@ -17,6 +17,8 @@ endif(HAVE_PCSC)
 add_library(srsue_upper STATIC ${SOURCES})
 target_link_libraries(srsue_upper ${ATOMIC_LIBS} srsran_asn1)
 
+target_link_libraries(srsue_upper nas_5g_msg)
+
 if(HAVE_PCSC)
   target_link_libraries(srsue_upper ${PCSCLITE_LIBRARY})
 endif(HAVE_PCSC)
\ No newline at end of file
diff --git a/srsue/src/stack/upper/nas_5g.cc b/srsue/src/stack/upper/nas_5g.cc
new file mode 100644
index 000000000..97718fc75
--- /dev/null
+++ b/srsue/src/stack/upper/nas_5g.cc
@@ -0,0 +1,236 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "srsue/hdr/stack/upper/nas_5g.h"
+#include "srsran/asn1/nas_5g_ies.h"
+#include "srsran/asn1/nas_5g_msg.h"
+#include "srsran/common/bcd_helpers.h"
+#include "srsran/common/security.h"
+#include "srsran/common/standard_streams.h"
+#include "srsran/common/string_helpers.h"
+#include "srsran/interfaces/ue_gw_interfaces.h"
+#include "srsran/interfaces/ue_rrc_interfaces.h"
+#include "srsran/interfaces/ue_usim_interfaces.h"
+#include "srsue/hdr/stack/upper/nas_5g_procedures.h"
+
+#include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <unistd.h>
+
+using namespace srsran;
+using namespace srsran::nas_5g;
+
+namespace srsue {
+
+/*********************************************************************
+ *   NAS 5G (NR)
+ ********************************************************************/
+
+nas_5g::nas_5g(srsran::task_sched_handle task_sched_) :
+  nas_base("NAS-5G"),
+  task_sched(task_sched_),
+  t3502(task_sched_.get_unique_timer()),
+  t3510(task_sched_.get_unique_timer()),
+  t3511(task_sched_.get_unique_timer()),
+  t3521(task_sched_.get_unique_timer()),
+  reregistration_timer(task_sched_.get_unique_timer()),
+  registration_proc(this)
+{
+  // Configure timers
+  t3502.set(t3502_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
+  t3510.set(t3510_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
+  t3511.set(t3511_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
+  t3521.set(t3521_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
+  reregistration_timer.set(reregistration_timer_duration_ms, [this](uint32_t tid) { timer_expired(tid); });
+}
+
+nas_5g::~nas_5g() {}
+
+void nas_5g::stop()
+{
+  running = false;
+}
+
+int nas_5g::init(usim_interface_nas*      usim_,
+                 rrc_nr_interface_nas_5g* rrc_nr_,
+                 gw_interface_nas*        gw_,
+                 const nas_args_t&        cfg_)
+{
+  usim   = usim_;
+  rrc_nr = rrc_nr_;
+  gw     = gw_;
+  cfg    = cfg_;
+
+  // parse and sanity check EIA list
+  if (parse_security_algorithm_list(cfg_.ia5g, ia5g_caps) != SRSRAN_SUCCESS) {
+    logger.warning("Failed to parse integrity algorithm list: Defaulting to 5G-EI1-128, 5G-EI2-128, 5G-EI3-128");
+    ia5g_caps[0] = false;
+    ia5g_caps[1] = true;
+    ia5g_caps[2] = true;
+    ia5g_caps[3] = true;
+  }
+
+  // parse and sanity check EEA list
+  if (parse_security_algorithm_list(cfg_.ea5g, ea5g_caps) != SRSRAN_SUCCESS) {
+    logger.warning(
+        "Failed to parse encryption algorithm list: Defaulting to 5G-EA0, 5G-EA1-128, 5G-EA2-128, 5G-EA3-128");
+    ea5g_caps[0] = true;
+    ea5g_caps[1] = true;
+    ea5g_caps[2] = true;
+    ea5g_caps[3] = true;
+  }
+
+  running = true;
+  return SRSRAN_SUCCESS;
+}
+
+void nas_5g::run_tti()
+{
+  // Process PLMN selection ongoing procedures
+  callbacks.run();
+
+  // Transmit intiating messages if necessary
+  switch (state.get_state()) {
+    case mm5g_state_t::state_t::deregistered:
+      // TODO Make sure cell selection is finished after transitioning from another state (if required)
+      // Make sure the RRC is finished transitioning to RRC Idle
+      if (reregistration_timer.is_running()) {
+        logger.debug("Waiting for re-attach timer to expire to attach again.");
+        return;
+      }
+      switch (state.get_deregistered_substate()) {
+        case mm5g_state_t::deregistered_substate_t::plmn_search:
+        case mm5g_state_t::deregistered_substate_t::normal_service:
+        case mm5g_state_t::deregistered_substate_t::initial_registration_needed:
+          registration_proc.launch();
+          break;
+        case mm5g_state_t::deregistered_substate_t::attempting_to_registration:
+        case mm5g_state_t::deregistered_substate_t::no_supi:
+        case mm5g_state_t::deregistered_substate_t::no_cell_available:
+        case mm5g_state_t::deregistered_substate_t::e_call_inactive:
+          logger.debug("Attempting to registration (not implemented) %s", state.get_full_state_text().c_str());
+        default:
+          break;
+      }
+    case mm5g_state_t::state_t::registered:
+      break;
+    case mm5g_state_t::state_t::deregistered_initiated:
+      logger.debug("UE detaching...");
+      break;
+    default:
+      break;
+  }
+}
+
+/*******************************************************************************
+ * Senders
+ ******************************************************************************/
+
+int nas_5g::send_registration_request()
+{
+  unique_byte_buffer_t pdu = srsran::make_byte_buffer();
+  if (!pdu) {
+    logger.error("Couldn't allocate PDU in %s().", __FUNCTION__);
+    return SRSRAN_ERROR;
+  }
+
+  logger.info("Generating registration request");
+
+  nas_5gs_msg             nas_msg;
+  registration_request_t& reg_req = nas_msg.set_registration_request();
+
+  reg_req.registration_type_5gs.follow_on_request_bit =
+      registration_type_5gs_t::follow_on_request_bit_type_::options::no_follow_on_request_pending;
+  reg_req.registration_type_5gs.registration_type =
+      registration_type_5gs_t::registration_type_type_::options::initial_registration;
+  mobile_identity_5gs_t::suci_s& suci = reg_req.mobile_identity_5gs.set_suci();
+  suci.supi_format                    = mobile_identity_5gs_t::suci_s::supi_format_type_::options::imsi;
+  mcc_to_bytes(0x0, suci.mcc.data());
+  uint8_t mnc_len;
+  mnc_to_bytes(0x0, suci.mnc.data(), &mnc_len);
+  suci.scheme_output.resize(15);
+  usim->get_imsi_vec(suci.scheme_output.data(), 15);
+  logger.info("Requesting IMSI attach (IMSI=%s)", usim->get_imsi_str().c_str());
+
+  if (nas_msg.pack(pdu) != SRSASN_SUCCESS) {
+    logger.error("Failed to pack registration request");
+    return SRSRAN_ERROR;
+  }
+
+  if (pcap != nullptr) {
+    pcap->write_nas(pdu.get()->msg, pdu.get()->N_bytes);
+  }
+
+  // start T3510
+  logger.debug("Starting T3410. Timeout in %d ms.", t3510.duration());
+  t3510.run();
+
+  state.set_registered_initiated();
+
+  return SRSRAN_SUCCESS;
+}
+
+/*******************************************************************************
+ * UE Stack and RRC common Interface
+ ******************************************************************************/
+bool nas_5g::is_registered()
+{
+  return state.get_state() == mm5g_state_t::state_t::registered;
+}
+
+/*******************************************************************************
+ * NAS Timers
+ ******************************************************************************/
+void nas_5g::timer_expired(uint32_t timeout_id)
+{
+  // TODO
+}
+
+/*******************************************************************************
+ * UE Stack Interface
+ ******************************************************************************/
+int nas_5g::switch_on()
+{
+  logger.info("Switching on");
+  state.set_deregistered(mm5g_state_t::deregistered_substate_t::plmn_search);
+  return SRSRAN_SUCCESS;
+}
+
+int nas_5g::switch_off()
+{
+  logger.info("Switching off");
+  // TODO
+  return SRSRAN_SUCCESS;
+}
+
+int nas_5g::enable_data()
+{
+  logger.info("Enabling data services");
+  return switch_on();
+}
+
+int nas_5g::disable_data()
+{
+  logger.info("Disabling data services");
+  // TODO
+  return SRSRAN_SUCCESS;
+}
+
+int nas_5g::start_service_request()
+{
+  logger.info("Service Request");
+  // TODO
+  return SRSRAN_SUCCESS;
+}
+
+} // namespace srsue
\ No newline at end of file
diff --git a/srsue/src/stack/upper/nas_5g_procedures.cc b/srsue/src/stack/upper/nas_5g_procedures.cc
new file mode 100644
index 000000000..bf2b80e2d
--- /dev/null
+++ b/srsue/src/stack/upper/nas_5g_procedures.cc
@@ -0,0 +1,38 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "srsue/hdr/stack/upper/nas_5g_procedures.h"
+
+#include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <unistd.h>
+
+using namespace srsran;
+
+namespace srsue {
+
+nas_5g::registration_procedure::registration_procedure(nas_5g_interface_procedures* parent_nas_) :
+  parent_nas(parent_nas_)
+{}
+
+srsran::proc_outcome_t nas_5g::registration_procedure::init()
+{
+  parent_nas->send_registration_request();
+  return srsran::proc_outcome_t::yield;
+}
+srsran::proc_outcome_t nas_5g::registration_procedure::step()
+{
+  return srsran::proc_outcome_t::success;
+}
+
+} // namespace srsue
\ No newline at end of file
diff --git a/srsue/src/stack/upper/nas_5gmm_state.cc b/srsue/src/stack/upper/nas_5gmm_state.cc
new file mode 100644
index 000000000..cc8ba316e
--- /dev/null
+++ b/srsue/src/stack/upper/nas_5gmm_state.cc
@@ -0,0 +1,149 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+#include "srsue/hdr/stack/upper/nas_5gmm_state.h"
+
+namespace srsue {
+
+// FSM setters
+void mm5g_state_t::set_null()
+{
+  state                 = state_t::null;
+  deregistered_substate = deregistered_substate_t::null;
+  registered_substate   = registered_substate_t::null;
+  logger.debug("Changed to mm5g state: %s", get_full_state_text().c_str());
+}
+
+void mm5g_state_t::set_deregistered(deregistered_substate_t substate)
+{
+  state                 = state_t::deregistered;
+  deregistered_substate = substate;
+  registered_substate   = registered_substate_t::null;
+  logger.debug("Changed to mm5g state: %s", get_full_state_text().c_str());
+}
+
+void mm5g_state_t::set_deregistered_initiated()
+{
+  state                 = state_t::deregistered_initiated;
+  deregistered_substate = deregistered_substate_t::null;
+  registered_substate   = registered_substate_t::null;
+  logger.debug("Changed to mm5g state: %s", get_full_state_text().c_str());
+}
+
+void mm5g_state_t::set_registered(registered_substate_t substate)
+{
+  state                 = state_t::registered;
+  deregistered_substate = deregistered_substate_t::null;
+  registered_substate   = substate;
+  logger.debug("Changed to mm5g state: %s", get_full_state_text().c_str());
+}
+
+void mm5g_state_t::set_registered_initiated()
+{
+  state                 = state_t::registered_initiated;
+  deregistered_substate = deregistered_substate_t::null;
+  registered_substate   = registered_substate_t::null;
+  logger.debug("Changed to mm5g state: %s", get_full_state_text().c_str());
+}
+
+void mm5g_state_t::set_service_request_initiated()
+{
+  state                 = state_t::service_request_initiated;
+  deregistered_substate = deregistered_substate_t::null;
+  registered_substate   = registered_substate_t::null;
+  logger.debug("Changed to mm5g state: %s", get_full_state_text().c_str());
+}
+
+const std::string mm5g_state_t::get_full_state_text()
+{
+  if (state == state_t::deregistered) {
+    return mm5g_state_text(state) + std::string(", with substate ") +
+           mm5g_deregistered_substate_text(deregistered_substate);
+  } else if (state == state_t::registered) {
+    return mm5g_state_text(state) + std::string(", with substate ") +
+           mm5g_registered_substate_text(registered_substate);
+  } else {
+    return mm5g_state_text(state);
+  }
+  return std::string("Invalid State");
+}
+
+/*
+ * Logging helper functions
+ */
+const char* mm5g_state_text(mm5g_state_t::state_t type)
+{
+  switch (type) {
+    case mm5g_state_t::state_t::null:
+      return "NULL";
+    case mm5g_state_t::state_t::deregistered:
+      return "DEREGISTERED";
+    case mm5g_state_t::state_t::registered_initiated:
+      return "REGISTERED-INITIATED";
+    case mm5g_state_t::state_t::registered:
+      return "REGISTERED";
+    case mm5g_state_t::state_t::deregistered_initiated:
+      return "DEREGISTERED-INITIATED";
+    case mm5g_state_t::state_t::service_request_initiated:
+      return "SERVICE-REQUEST-INITIATED";
+  }
+  return "INVALID";
+}
+
+const char* mm5g_deregistered_substate_text(mm5g_state_t::deregistered_substate_t type)
+{
+  switch (type) {
+    case mm5g_state_t::deregistered_substate_t::null:
+      return "NULL";
+    case mm5g_state_t::deregistered_substate_t::normal_service:
+      return "NORMAL-SERVICE";
+    case mm5g_state_t::deregistered_substate_t::limited_service:
+      return "LIMITED-SERVICE";
+    case mm5g_state_t::deregistered_substate_t::attempting_to_registration:
+      return "ATTEMPTING-TO-REGISTRATION";
+    case mm5g_state_t::deregistered_substate_t::plmn_search:
+      return "PLMN-SEARCH";
+    case mm5g_state_t::deregistered_substate_t::no_supi:
+      return "NO-SUPI";
+    case mm5g_state_t::deregistered_substate_t::no_cell_available:
+      return "NO-CELL-AVAILABLE";
+    case mm5g_state_t::deregistered_substate_t::e_call_inactive:
+      return "eCALL-INACTIVE";
+    case mm5g_state_t::deregistered_substate_t::initial_registration_needed:
+      return "ATTACH-NEEDED";
+  }
+  return "INVALID";
+}
+
+const char* mm5g_registered_substate_text(mm5g_state_t::registered_substate_t type)
+{
+  switch (type) {
+    case mm5g_state_t::registered_substate_t::null:
+      return "NULL";
+    case mm5g_state_t::registered_substate_t::normal_service:
+      return "NORMAL-SERVICE";
+    case mm5g_state_t::registered_substate_t::non_allowed_service:
+      return "NON-ALLOWED-SERVICE";
+    case mm5g_state_t::registered_substate_t::attempting_registration_update:
+      return "ATTEMPTING-REGISTRATION-UPDATE";
+    case mm5g_state_t::registered_substate_t::limited_service:
+      return "LIMITED-SERVICE";
+    case mm5g_state_t::registered_substate_t::plmn_search:
+      return "PLMN-SEARCH";
+    case mm5g_state_t::registered_substate_t::no_cell_available:
+      return "NO-CELL-AVAILABLE";
+    case mm5g_state_t::registered_substate_t::update_needed:
+      return "UPDATE-NEEDED";
+  }
+  return "INVALID";
+}
+
+} // namespace srsue
diff --git a/srsue/src/stack/upper/test/CMakeLists.txt b/srsue/src/stack/upper/test/CMakeLists.txt
index 56dc8c469..8ba97816a 100644
--- a/srsue/src/stack/upper/test/CMakeLists.txt
+++ b/srsue/src/stack/upper/test/CMakeLists.txt
@@ -19,6 +19,10 @@ add_executable(nas_test nas_test.cc)
 target_link_libraries(nas_test srsue_upper srsran_common srsran_phy rrc_asn1 srsran_asn1)
 add_test(nas_test nas_test)
 
+add_executable(nas_5g_test nas_5g_test.cc)
+target_link_libraries(nas_5g_test srsue_upper srsran_phy rrc_asn1)
+add_test(nas_5g_test nas_5g_test)
+
 add_executable(gw_test gw_test.cc)
 target_link_libraries(gw_test srsue_upper srsran_common srsran_phy)
 add_test(gw_test gw_test)
diff --git a/srsue/src/stack/upper/test/nas_5g_test.cc b/srsue/src/stack/upper/test/nas_5g_test.cc
new file mode 100644
index 000000000..8556e326a
--- /dev/null
+++ b/srsue/src/stack/upper/test/nas_5g_test.cc
@@ -0,0 +1,108 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2021 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "srsran/common/bcd_helpers.h"
+#include "srsran/common/test_common.h"
+#include "srsran/common/tsan_options.h"
+#include "srsran/interfaces/ue_pdcp_interfaces.h"
+#include "srsran/srslog/srslog.h"
+#include "srsran/test/ue_test_interfaces.h"
+#include "srsue/hdr/stack/upper/gw.h"
+#include "srsue/hdr/stack/upper/nas_5g.h"
+#include "srsue/hdr/stack/upper/test/nas_test_common.h"
+
+using namespace srsue;
+using namespace srsran;
+
+#define HAVE_PCAP 0
+
+int amf_attach_request_test(srsran::nas_pcap* pcap)
+{
+  int ret = SRSRAN_ERROR;
+
+  rrc_nr_dummy rrc_nr_dummy;
+  pdcp_dummy   pdcp_dummy;
+
+  srsue::usim usim(srslog::fetch_basic_logger("USIM"));
+  usim_args_t args;
+  args.mode = "soft";
+  args.algo = "xor";
+  args.imei = "353490069873319";
+  args.imsi = "001010123456789";
+  args.k    = "00112233445566778899aabbccddeeff";
+  args.op   = "63BFA50EE6523365FF14C1F45F88737D";
+  usim.init(&args);
+
+  nas_args_t nas_cfg;
+  nas_cfg.force_imsi_attach = true;
+  nas_cfg.apn_name          = "test123";
+  nas_cfg.ia5g              = "0,1,2,3";
+  nas_cfg.ea5g              = "0,1,2,3";
+
+  test_stack_dummy<srsue::nas_5g> stack(&pdcp_dummy);
+  srsue::nas_5g                   nas_5g(&stack.task_sched);
+  srsue::gw                       gw;
+
+  if (pcap != nullptr) {
+    nas_5g.start_pcap(pcap);
+  }
+
+  gw_args_t gw_args;
+  gw_args.tun_dev_name     = "tun0";
+  gw_args.log.gw_level     = "debug";
+  gw_args.log.gw_hex_limit = 100000;
+
+  gw.init(gw_args, &stack);
+  stack.init(&nas_5g);
+
+  nas_5g.init(&usim, &rrc_nr_dummy, &gw, nas_cfg);
+  rrc_nr_dummy.init(&nas_5g);
+
+  // trigger test
+  stack.switch_on();
+  stack.stop();
+
+  gw.stop();
+  ret = SRSRAN_SUCCESS;
+
+  return ret;
+}
+
+int main(int argc, char** argv)
+{
+  // Setup logging.
+  auto& rrc_logger = srslog::fetch_basic_logger("RRC", false);
+  rrc_logger.set_level(srslog::basic_levels::debug);
+  rrc_logger.set_hex_dump_max_size(100000);
+  auto& nas_logger = srslog::fetch_basic_logger("NAS", false);
+  nas_logger.set_level(srslog::basic_levels::debug);
+  nas_logger.set_hex_dump_max_size(100000);
+  auto& usim_logger = srslog::fetch_basic_logger("USIM", false);
+  usim_logger.set_level(srslog::basic_levels::debug);
+  usim_logger.set_hex_dump_max_size(100000);
+  auto& gw_logger = srslog::fetch_basic_logger("GW", false);
+  gw_logger.set_level(srslog::basic_levels::debug);
+  gw_logger.set_hex_dump_max_size(100000);
+
+  // Start the log backend.
+  srslog::init();
+#if HAVE_PCAP
+  srsran::nas_pcap pcap;
+  pcap.open("nas_5g_test.pcap", 0, srsran::srsran_rat_t::nr);
+  TESTASSERT(amf_attach_request_test(&pcap) == SRSRAN_SUCCESS);
+  pcap.close();
+#else
+  TESTASSERT(amf_attach_request_test(nullptr) == SRSRAN_SUCCESS);
+#endif // HAVE_PCAP
+
+  return SRSRAN_SUCCESS;
+}