Added mac prach nr proc error handling

lib/src/mac/mac_rar_pdu_nr.cc

@@ -121,6 +121,11 @@ void mac_rar_subpdu_nr::set_backoff(const uint8_t backoff_indicator_)
   backoff_indicator = backoff_indicator_;
 }
 
+uint8_t mac_rar_subpdu_nr::get_backoff() const
+{
+  return backoff_indicator;
+}
+
 std::array<uint8_t, mac_rar_subpdu_nr::UL_GRANT_NBITS> mac_rar_subpdu_nr::get_ul_grant() const
 {
   return ul_grant;

srsue/hdr/stack/mac_nr/mac_nr.h

@@ -87,6 +87,9 @@ public:
   bool msg3_is_pending() { return mux.msg3_is_pending(); }
   bool msg3_is_empty() { return mux.msg3_is_empty(); }
 
+  /// RRC
+  void rrc_ra_problem() { rrc->ra_problem(); }
+
   /// stack interface
   void process_pdus();
 

srsue/hdr/stack/mac_nr/mac_nr_interfaces.h

@@ -32,6 +32,9 @@ public:
   virtual void msg3_flush()          = 0;
   virtual void msg3_prepare()        = 0;
   virtual bool msg3_is_empty()       = 0;
+
+  // RRC functions
+  virtual void rrc_ra_problem() = 0;
 };
 
 /**

srsue/hdr/stack/mac_nr/proc_ra_nr.h

@@ -82,10 +82,12 @@ private:
   srsran::timer_handler::unique_timer prach_send_timer;
   srsran::timer_handler::unique_timer rar_timeout_timer;
   srsran::timer_handler::unique_timer contention_resolution_timer;
+  srsran::timer_handler::unique_timer backoff_timer;
 
   // 38.321 5.1.1 Variables
   uint32_t preamble_index = 0;
   uint32_t preamble_transmission_counter = 0;
+  uint32_t preamble_backoff               = 0; // in ms
   uint32_t preamble_power_ramping_step = 0;
   int preamble_received_target_power = 0;
   uint32_t scaling_factor_bi = 0;

srsue/hdr/stack/rrc/rrc_nr.h

@@ -96,13 +96,12 @@ public:
   void in_sync() final;
   void out_of_sync() final;
 
-  // MAC interface
-  void run_tti(uint32_t tti) final;
 
   // RLC interface
   void max_retx_attempted() final;
 
   // MAC interface
+  void run_tti(uint32_t tti) final;
   void ra_completed() final;
   void ra_problem() final;
   void release_pucch_srs() final;

srsue/src/stack/mac_nr/mac_nr.cc

@@ -322,7 +322,7 @@ bool mac_nr::set_crnti(const uint16_t c_rnti_)
 
 void mac_nr::start_ra_procedure()
 {
-  proc_ra.start_by_rrc();
+  stack_task_dispatch_queue.push([this]() {proc_ra.start_by_rrc();});
 }
 
 bool mac_nr::is_valid_crnti(const uint16_t crnti)

srsue/src/stack/mac_nr/proc_ra_nr.cc

@@ -40,6 +40,7 @@ void proc_ra_nr::init(phy_interface_mac_nr* phy_, srsran::ext_task_sched_handle*
   prach_send_timer            = task_sched->get_unique_timer();
   rar_timeout_timer           = task_sched->get_unique_timer();
   contention_resolution_timer = task_sched->get_unique_timer();
+  backoff_timer               = task_sched->get_unique_timer();
 }
 
 /* Sets a new configuration. The configuration is applied by initialization() function */
@@ -124,15 +125,18 @@ uint16_t proc_ra_nr::get_temp_rnti()
 void proc_ra_nr::timer_expired(uint32_t timer_id)
 {
   if (prach_send_timer.id() == timer_id) {
-    logger.error("PRACH Send timer expired. PRACH was not transmitted within %d ttis by phy. (TODO)",
+    logger.warning("PRACH Send timer expired. PRACH was not transmitted within %d ttis by phy. (TODO)",
                  prach_send_timer.duration());
     ra_error();
   } else if (rar_timeout_timer.id() == timer_id) {
-    logger.error("RAR Timer expired. RA response not received within the response window Response Error (TODO)");
+    logger.warning("RAR Timer expired. RA response not received within the response window");
     ra_error();
   } else if (contention_resolution_timer.id() == timer_id) {
-    logger.error("Contention Resolution Timer expired. Stopping PDCCH Search and going to Response Error (TODO)");
+    logger.warning("Contention Resolution Timer expired. Stopping PDCCH Search and going to Response Error (TODO)");
     ra_error();
+  } else if (backoff_timer.id() == timer_id) {
+    logger.info("Transmitting new preamble (%d/%d)", preamble_transmission_counter, rach_cfg.preambleTransMax);
+    ra_resource_selection();
   } else {
     logger.error("Timer not implemented");
   }
@@ -142,8 +146,10 @@ void proc_ra_nr::timer_expired(uint32_t timer_id)
 void proc_ra_nr::ra_procedure_initialization()
 {
   mac.msg3_flush();
+  preamble_transmission_counter = 1;
   preamble_power_ramping_step = rach_cfg.powerRampingStep;
   scaling_factor_bi           = 1;
+  preamble_backoff              = 0;
   preambleTransMax            = rach_cfg.preambleTransMax;
   ra_resource_selection();
 }
@@ -205,6 +211,13 @@ void proc_ra_nr::ra_response_reception(const mac_interface_phy_nr::mac_nr_grant_
           rar_rnti = SRSRAN_INVALID_RNTI;
           mac.msg3_prepare();
           current_ta = subpdu.get_ta();
+
+          // Set Backoff parameter
+          if (subpdu.has_backoff()) {
+            preamble_backoff = backoff_table_nr[subpdu.get_backoff() % 16]; // TODO multiplied with SCALING_FACTOR_BI.
+          } else {
+            preamble_backoff = 0;
+          }
         }
       }
     }
@@ -265,7 +278,31 @@ void proc_ra_nr::ra_completion()
 
 void proc_ra_nr::ra_error()
 {
-  logger.error("NR random access procedure error recovery not implemented yet");
+  temp_rnti = 0;
+  preamble_transmission_counter++;
+  contention_resolution_timer.stop();
+  uint32_t backoff_wait;
+  bool     ra_procedure_completed = false; // true = (unsuccessfully) completed, false = uncompleted
+
+  if (preamble_transmission_counter >= rach_cfg.preambleTransMax + 1) {
+    logger.warning("Maximum number of transmissions reached (%d)", rach_cfg.preambleTransMax);
+    // if the Random Access Preamble is transmitted on the SpCell assumption (TODO)
+    mac.rrc_ra_problem();                 //  indicate a Random Access problem to upper layers;
+    if (started_by == initiators_t::MAC) { // if this Random Access procedure was triggered for SI request
+      ra_procedure_completed = true;        // consider the Random Access procedure unsuccessfully completed.
+      reset();
+    }
+  } else {
+    // if the Random Access procedure is not completed
+    if (preamble_backoff) {
+      backoff_wait = rand() % preamble_backoff;
+    } else {
+      backoff_wait = 0;
+    }
+    logger.warning("Backoff wait interval %d", backoff_wait);
+    backoff_timer.set(backoff_wait, [this](uint32_t tid) { timer_expired(tid); });
+    backoff_timer.run();
+  }
 }
 
 // Is called by PHY once it has transmitted the prach transmitted, than configure RA-RNTI and wait for RAR reception
@@ -297,7 +334,7 @@ void proc_ra_nr::prach_sent(uint32_t tti, uint32_t s_id, uint32_t t_id, uint32_t
                     tti);
     uint32_t rar_window_st = TTI_ADD(tti, 3);
     // TODO check ra_response window (delayed start)? // last 3 check if needed when we have a delayed start
-    rar_timeout_timer.set(rach_cfg.ra_responseWindow + 3 + 3, [this](uint32_t tid) { timer_expired(tid); });
+    rar_timeout_timer.set(rach_cfg.ra_responseWindow + 3 + 10, [this](uint32_t tid) { timer_expired(tid); });
     rar_timeout_timer.run();
     // Wait for RAR reception
     ra_window_length = rach_cfg.ra_responseWindow;

srsue/src/stack/rrc/rrc_nr.cc

@@ -1190,7 +1190,11 @@ void rrc_nr::max_retx_attempted() {}
 
 // MAC interface
 void rrc_nr::ra_completed() {}
-void rrc_nr::ra_problem() {}
+void rrc_nr::ra_problem()
+{
+  rrc_eutra->nr_scg_failure_information(scg_failure_cause_t::random_access_problem);
+}
+
 void rrc_nr::release_pucch_srs() {}
 
 // STACK interface
@@ -1245,7 +1249,7 @@ proc_outcome_t rrc_nr::connection_reconf_no_ho_proc::init(const reconf_initiator
         return proc_outcome_t::error;
       }
 
-      rrc_ptr->log_rrc_message("RRC NR Reconfiguration",
+      rrc_ptr->log_rrc_message("RRC NRf Reconfiguration",
                                Rx,
                                rrc_recfg.crit_exts.rrc_recfg().secondary_cell_group,
                                cell_group_cfg,

srsue/test/mac_nr/proc_ra_nr_test.cc

@@ -53,6 +53,7 @@ private:
 class dummy_mac : public mac_interface_proc_ra_nr
 {
 public:
+  dummy_mac() : logger(srslog::fetch_basic_logger("MAC")) {}
   uint64_t get_contention_id() { return 0xdeadbeaf; }
   uint16_t get_crnti() { return crnti; }
   bool     set_crnti(uint16_t c_rnti)
@@ -67,26 +68,24 @@ public:
   bool msg3_is_empty() { return true; }
 
   void msga_flush(){};
+  // RRC RA problem
+  void rrc_ra_problem() { logger.warning("Dummy MAC RRC ra problem"); }
 
 private:
-  uint16_t crnti = SRSRAN_INVALID_RNTI;
+  uint16_t             crnti = SRSRAN_INVALID_RNTI;
+  srslog::basic_logger& logger;
 };
 
-int main()
+int proc_ra_normal_test()
 {
-  srslog::init();
-  auto& mac_logger = srslog::fetch_basic_logger("MAC");
-  mac_logger.set_level(srslog::basic_levels::debug);
-  mac_logger.set_hex_dump_max_size(-1);
-
   dummy_phy                     dummy_phy;
   dummy_mac                     dummy_mac;
   srsran::task_scheduler        task_sched{5, 2};
   srsran::ext_task_sched_handle ext_task_sched_h(&task_sched);
 
-  proc_ra_nr proc_ra_nr(dummy_mac, mac_logger);
+  proc_ra_nr proc_ra_nr(dummy_mac, srslog::fetch_basic_logger("MAC"));
-
   proc_ra_nr.init(&dummy_phy, &ext_task_sched_h);
+
   TESTASSERT(proc_ra_nr.is_rar_opportunity(1) == false);
   srsran::rach_nr_cfg_t rach_cfg;
   rach_cfg.powerRampingStep             = 4;
@@ -105,7 +104,7 @@ int main()
   dummy_phy.get_last_send_prach(&prach_occasion, &preamble_index, &preamble_received_target_power);
   TESTASSERT(prach_occasion == 0);
   TESTASSERT(preamble_index == 0);
-  TESTASSERT(preamble_received_target_power == -114);
+  TESTASSERT(preamble_received_target_power == -110);
   // Simulate PHY and call prach_sent (random values)
   uint32_t tti_start = 0;
   proc_ra_nr.prach_sent(tti_start, 7, 1, 0, 0);
@@ -135,9 +134,64 @@ int main()
   task_sched.tic();
   task_sched.run_pending_tasks();
 
-  proc_ra_nr.pdcch_to_crnti();
+  return SRSRAN_SUCCESS;
+}
 
+int proc_ra_timeout_test()
+{
+  dummy_phy                     dummy_phy;
+  dummy_mac                     dummy_mac;
+  srsran::task_scheduler        task_sched{5, 2};
+  srsran::ext_task_sched_handle ext_task_sched_h(&task_sched);
+
+  proc_ra_nr proc_ra_nr(dummy_mac, srslog::fetch_basic_logger("MAC"));
+
+  proc_ra_nr.init(&dummy_phy, &ext_task_sched_h);
+  TESTASSERT(proc_ra_nr.is_rar_opportunity(1) == false);
+  srsran::rach_nr_cfg_t rach_cfg;
+  rach_cfg.powerRampingStep             = 4;
+  rach_cfg.prach_ConfigurationIndex     = 16;
+  rach_cfg.PreambleReceivedTargetPower  = -110;
+  rach_cfg.preambleTransMax             = 7;
+  rach_cfg.ra_ContentionResolutionTimer = 64;
+  rach_cfg.ra_responseWindow            = 10;
+  proc_ra_nr.set_config(rach_cfg);
+  proc_ra_nr.start_by_rrc();
+
+  // Test send prach parameters
+  uint32_t prach_occasion                 = 0;
+  uint32_t preamble_index                 = 0;
+  int      preamble_received_target_power = 0;
+  dummy_phy.get_last_send_prach(&prach_occasion, &preamble_index, &preamble_received_target_power);
+  TESTASSERT(prach_occasion == 0);
+  TESTASSERT(preamble_index == 0);
+  TESTASSERT(preamble_received_target_power == -110);
+  // Simulate PHY and call prach_sent (random values)
+  uint32_t tti = 0;
+
+  for (uint32_t j = 0; j < rach_cfg.preambleTransMax; j++) {
+    proc_ra_nr.prach_sent(tti, 7, 1, 0, 0);
+    uint32_t i = 0;
+    for (i = tti; i < tti + rach_cfg.ra_responseWindow + 100; i++) {
+      // update clock and run internal tasks
+      task_sched.tic();
+      task_sched.run_pending_tasks();
+    }
+    tti = i;
+  }
   task_sched.tic();
   task_sched.run_pending_tasks();
   return SRSRAN_SUCCESS;
 }
+
+int main()
+{
+  srslog::init();
+
+  auto& mac_logger = srslog::fetch_basic_logger("MAC");
+  mac_logger.set_level(srslog::basic_levels::debug);
+  mac_logger.set_hex_dump_max_size(-1);
+  // TESTASSERT(proc_ra_normal_test() == SRSRAN_SUCCESS);
+  TESTASSERT(proc_ra_timeout_test() == SRSRAN_SUCCESS);
+  return SRSRAN_SUCCESS;
+}