Changed counting of KOs to RRC

srsenb/hdr/enb.h

@@ -93,6 +93,7 @@ struct general_args_t {
   std::string tracing_filename;
   std::string eia_pref_list;
   std::string eea_pref_list;
+  uint32_t    max_mac_dl_kos;
 };
 
 struct all_args_t {

srsenb/hdr/stack/rrc/rrc.h

@@ -181,11 +181,12 @@ private:
     srsran::unique_byte_buffer_t pdu;
   } rrc_pdu;
 
-  const static uint32_t LCID_EXIT     = 0xffff0000;
-  const static uint32_t LCID_REM_USER = 0xffff0001;
-  const static uint32_t LCID_REL_USER = 0xffff0002;
-  const static uint32_t LCID_ACT_USER = 0xffff0004;
-  const static uint32_t LCID_RTX_USER = 0xffff0005;
+  const static uint32_t LCID_EXIT        = 0xffff0000;
+  const static uint32_t LCID_REM_USER    = 0xffff0001;
+  const static uint32_t LCID_REL_USER    = 0xffff0002;
+  const static uint32_t LCID_ACT_USER    = 0xffff0004;
+  const static uint32_t LCID_RTX_USER    = 0xffff0005;
+  const static uint32_t LCID_MAC_KO_USER = 0xffff0006;
 
   bool                                running = false;
   srsran::dyn_blocking_queue<rrc_pdu> rx_pdu_queue;

srsenb/hdr/stack/rrc/rrc_config.h

@@ -59,6 +59,7 @@ struct rrc_cfg_t {
   srsran_cell_t                                                                           cell;
   cell_list_t                                                                             cell_list;
   cell_list_t                                                                             cell_list_nr;
+  uint32_t                                                                                max_mac_dl_kos;
 };
 
 constexpr uint32_t UE_PCELL_CC_IDX = 0;

srsenb/hdr/stack/rrc/rrc_ue.h

@@ -41,6 +41,7 @@ public:
   std::string to_string(const activity_timeout_type_t& type);
   void        set_activity_timeout(const activity_timeout_type_t type);
   void        set_activity();
+  void        mac_ko_activity();
   void        activity_timer_expired(const activity_timeout_type_t type);
   void        max_retx_reached();
 
@@ -182,6 +183,9 @@ private:
 
   const static uint32_t UE_PCELL_CC_IDX = 0;
 
+  uint32_t consecutive_kos = 0;
+  uint32_t max_mac_dl_retx;
+
   ue_cell_ded_list     ue_cell_list;
   bearer_cfg_handler   bearer_list;
   security_cfg_handler ue_security_cfg;

srsenb/src/enb_cfg_parser.cc

@@ -1135,6 +1135,9 @@ int set_derived_args(all_args_t* args_, rrc_cfg_t* rrc_cfg_, phy_cfg_t* phy_cfg_
   // RRC needs eNB id for SIB1 packing
   rrc_cfg_->enb_id = args_->stack.s1ap.enb_id;
 
+  // Set max number of KOs
+  rrc_cfg_->max_mac_dl_kos = args_->general.max_mac_dl_kos;
+
   // Set sync queue capacity to 1 for ZMQ
   if (args_->rf.device_name == "zmq") {
     srslog::fetch_basic_logger("ENB").info("Using sync queue size of one for ZMQ based radio.");

srsenb/src/main.cc

@@ -214,7 +214,7 @@ void parse_args(all_args_t* args, int argc, char* argv[])
     ("expert.eea_pref_list", bpo::value<string>(&args->general.eea_pref_list)->default_value("EEA0, EEA2, EEA1"), "Ordered preference list for the selection of encryption algorithm (EEA) (default: EEA0, EEA2, EEA1).")
     ("expert.eia_pref_list", bpo::value<string>(&args->general.eia_pref_list)->default_value("EIA2, EIA1, EIA0"), "Ordered preference list for the selection of integrity algorithm (EIA) (default: EIA2, EIA1, EIA0).")
     ("expert.max_nof_ues", bpo::value<uint32_t>(&args->stack.mac.max_nof_ues)->default_value(64), "Maximum number of connected UEs")
-    ("expert.max_nof_kos", bpo::value<uint32_t>(&args->stack.mac.max_nof_kos)->default_value(254), "Maximum number of consecutive KOs before triggering the UE's release")
+    ("expert.max_mac_dl_kos", bpo::value<uint32_t>(&args->general.max_mac_dl_kos)->default_value(30), "Maximum number of consecutive KOs before triggering the UE's release")
 
     // eMBMS section
     ("embms.enable", bpo::value<bool>(&args->stack.embms.enable)->default_value(false), "Enables MBMS in the eNB")

srsenb/src/stack/mac/mac.cc

@@ -292,17 +292,13 @@ int mac::ack_info(uint32_t tti_rx, uint16_t rnti, uint32_t enb_cc_idx, uint32_t
   ue_db[rnti]->metrics_tx(ack, nof_bytes);
 
   if (ack) {
-    ue_db[rnti]->ko_counter = 0;
     if (nof_bytes > 64) { // do not count RLC status messages only
       rrc_h->set_activity_user(rnti, true);
       logger.info("DL activity rnti=0x%x, n_bytes=%d", rnti, nof_bytes);
     }
   } else {
-    ue_db[rnti]->ko_counter++;
-    if (ue_db[rnti]->ko_counter > args.max_nof_kos) {
-      rrc_h->set_activity_user(rnti, false);
-      logger.info("DL max KOs reached rnti=0x%x, n_bytes=%d", rnti, nof_bytes);
-    }
+    rrc_h->set_activity_user(rnti, false);
+    logger.info("DL KO activity rnti=0x%x, n_bytes=%d", rnti, nof_bytes);
   }
   return SRSRAN_SUCCESS;
 }

srsenb/src/stack/rrc/rrc.cc

@@ -85,6 +85,7 @@ int32_t rrc::init(const rrc_cfg_t&       cfg_,
                    "re-establishment procedure.");
   }
   logger.info("Inactivity timeout: %d ms", cfg.inactivity_timeout_ms);
+  logger.info("Max consecutive MAC KOs: %d", cfg.max_mac_dl_kos);
 
   running = true;
 
@@ -137,7 +138,7 @@ void rrc::set_activity_user(uint16_t rnti, bool ack_info)
   if (ack_info) {
     p = {rnti, LCID_ACT_USER, nullptr};
   } else {
-    p = {rnti, LCID_RTX_USER, nullptr};
+    p = {rnti, LCID_MAC_KO_USER, nullptr};
   }
 
   if (not rx_pdu_queue.try_push(std::move(p))) {
@@ -1025,6 +1026,9 @@ void rrc::tti_clock()
       case LCID_ACT_USER:
         user_it->second->set_activity();
         break;
+      case LCID_MAC_KO_USER:
+        user_it->second->mac_ko_activity();
+        break;
       case LCID_RTX_USER:
         user_it->second->max_retx_reached();
         break;

srsenb/src/stack/rrc/rrc_ue.cc

@@ -103,12 +103,29 @@ void rrc::ue::set_activity()
 {
   // re-start activity timer with current timeout value
   activity_timer.run();
+  consecutive_kos = 0;
   if (parent) {
     parent->logger.debug("Activity registered for rnti=0x%x (timeout_value=%dms)", rnti, activity_timer.duration());
   }
 }
 
-void rrc::ue::activity_timer_expired(activity_timeout_type_t type)
+void rrc::ue::mac_ko_activity()
+{
+  // Count KOs in MAC and trigger release if it goes above a certain value.
+  // This is done to detect out-of-coverage UEs
+  consecutive_kos++;
+  parent->logger.debug("KO activity registered for rnti=0x%x (consecutive_kos=%d, max_mac_dl_kos=%d)",
+                       rnti,
+                       consecutive_kos,
+                       parent->cfg.max_mac_dl_kos);
+
+  if (consecutive_kos > parent->cfg.max_mac_dl_kos) {
+    parent->logger.debug("Max KOs reached, triggering release rnti=0x%x", rnti);
+    max_retx_reached();
+  }
+}
+
+void rrc::ue::activity_timer_expired(const activity_timeout_type_t type)
 {
   if (parent) {
     parent->logger.info("Activity timer for rnti=0x%x expired after %d ms", rnti, activity_timer.time_elapsed());