Fixed cell search for non-home PLMN

lib/include/srslte/interfaces/ue_interfaces.h

@@ -580,7 +580,6 @@ public:
 
   /* Cell search and selection procedures */
   virtual void cell_search_start() = 0;
-  virtual void cell_search_stop() = 0;
   virtual void cell_search_next() = 0;
   virtual void cell_select(uint32_t earfcn, srslte_cell_t cell) = 0;
   virtual bool cell_handover(srslte_cell_t cell) = 0;

lib/src/phy/ue/ue_sync.c

@@ -755,7 +755,9 @@ int srslte_ue_sync_zerocopy_multi(srslte_ue_sync_t *q, cf_t *input_buffer[SRSLTE
           if (q->do_agc) {
             srslte_agc_process(&q->agc, input_buffer[0], q->sf_len);        
           }
-          
+
+          INFO("SYNC FIND: sf_idx=%d, ret=%d, next_state=%d\n", q->sf_idx, ret, q->state);
+
         break;
         case SF_TRACK:
          
@@ -817,6 +819,9 @@ int srslte_ue_sync_zerocopy_multi(srslte_ue_sync_t *q, cf_t *input_buffer[SRSLTE
 
             q->frame_total_cnt++;
           }
+
+          INFO("SYNC TRACK: sf_idx=%d, ret=%d, next_state=%d\n", q->sf_idx, ret, q->state);
+
         break;
       }
     }

srsue/hdr/phy/phch_recv.h

@@ -61,7 +61,6 @@ public:
   
   void    reset_sync();
   void    cell_search_start();
-  void    cell_search_stop();
   void    cell_search_next(bool reset = false);
   void    cell_select(uint32_t earfcn, srslte_cell_t cell);
   bool    cell_handover(srslte_cell_t cell);
@@ -299,14 +298,16 @@ private:
   const static uint32_t NOF_IN_SYNC_SF     = 100;
 
   // State for primary cell
-  enum {
+  typedef enum {
     IDLE = 0,
     CELL_SEARCH,
     CELL_SELECT,
     CELL_RESELECT,
     CELL_MEASURE,
     CELL_CAMP,
-  } phy_state;
+  } phy_state_t;
+
+  phy_state_t phy_state, prev_state;
 
   bool is_in_idle;
 
@@ -330,7 +331,6 @@ private:
   float         ul_dl_factor;
   uint32_t      current_earfcn;
   int           cur_earfcn_index;
-  bool          cell_search_in_progress;
 
   float         dl_freq;
   float         ul_freq;

srsue/hdr/phy/phy.h

@@ -85,7 +85,6 @@ public:
   void    sync_reset();
   void    configure_ul_params(bool pregen_disabled = false);
   void    cell_search_start();
-  void    cell_search_stop();
   void    cell_search_next();
   void    cell_select(uint32_t earfcn, srslte_cell_t phy_cell);
   bool    cell_handover(srslte_cell_t cell);

srsue/src/phy/phch_recv.cc

@@ -132,7 +132,6 @@ void phch_recv::reset()
   next_offset  = 0;
   cell_is_set = false;
   srate_mode = SRATE_NONE;
-  cell_search_in_progress = false;
   current_earfcn = 0;
   sfn_p.reset();
   measure_p.reset();
@@ -262,17 +261,17 @@ void phch_recv::reset_sync() {
   search_p.reset();
   measure_p.reset();
   srslte_ue_sync_reset(&ue_sync);
-
+  Info("----- PHY RESET----\n");
   phy_state = CELL_SELECT;
 }
 
 void phch_recv::cell_search_inc()
 {
+  Info("cell_search_inc, cur_idx=%d, size=%d\n", cur_earfcn_index, earfcn.size());
   cur_earfcn_index++;
   if (cur_earfcn_index >= 0) {
     if (cur_earfcn_index >= (int) earfcn.size()) {
       cur_earfcn_index = 0;
-      cell_search_in_progress = false;
       phy_state = IDLE;
       rrc->earfcn_end();
     } else {
@@ -281,20 +280,16 @@ void phch_recv::cell_search_inc()
         current_earfcn = earfcn[cur_earfcn_index];
         set_frequency();
       }
+      phy_state = CELL_SEARCH;
     }
   }
 }
 
 void phch_recv::cell_search_next(bool reset) {
-  if (cell_search_in_progress || reset) {
+  if (reset) {
-    cell_search_in_progress = false;
+    cur_earfcn_index = -1;
-    if (reset) {
-      cur_earfcn_index = -1;
-    }
-    cell_search_inc();
-    phy_state = CELL_SEARCH;
-    cell_search_in_progress = true;
   }
+  cell_search_inc();
 }
 
 void phch_recv::cell_search_start() {
@@ -311,11 +306,6 @@ void phch_recv::cell_search_start() {
   }
 }
 
-void phch_recv::cell_search_stop() {
-  Info("SYNC:  Stopping Cell Search procedure...\n");
-  cell_search_in_progress = false;
-}
-
 bool phch_recv::cell_handover(srslte_cell_t cell)
 {
   int cnt = 0;
@@ -369,19 +359,18 @@ void phch_recv::cell_reselect()
   uint32_t earfcn = new_earfcn;
   srslte_cell_t cell = new_cell;
 
+  Info("Reset from cell_reselect\n");
+  reset_sync();
+
   // If we are already in the new cell, just resynchronize
   if (earfcn == current_earfcn && this->cell.id == cell.id) {
-    log_h->info("Cell Select: Already in cell EARFCN=%d\n", earfcn);
+    log_h->info("Cell Select: Already in cell EARFCN=%d, PCI=%d\n", earfcn, cell.id);
-    cell_search_in_progress = false;
     if (srate_mode != SRATE_CAMP) {
       set_sampling_rate();
+      log_h->info("Cell Select: Setting Camping sampling rate\n");
     }
-    phy_state = CELL_SELECT;
   } else {
 
-    /* If we are going to a new cell, configure it */
-    cell_search_in_progress = false;
-
     if (earfcn != current_earfcn) {
       if (set_frequency()) {
         log_h->error("Cell Select: Configuring cell in EARFCN=%d, PCI=%d\n", earfcn, cell.id);
@@ -394,7 +383,6 @@ void phch_recv::cell_reselect()
 
     if (set_cell()) {
       log_h->info("Cell Select: Synchronizing on cell...\n");
-      phy_state = CELL_SELECT;
     }
   }
 }
@@ -533,33 +521,29 @@ void phch_recv::run_thread()
     
     sf_idx = tti%10;
 
+    prev_state = phy_state;
+
     switch (phy_state) {
       case CELL_SEARCH:
-        if (cell_search_in_progress)
+        switch(search_p.run(&cell))
         {
-          switch(search_p.run(&cell))
+        case search::CELL_FOUND:
-          {
+          if (!srslte_cell_isvalid(&cell)) {
-          case search::CELL_FOUND:
+            Error("SYNC:  Detected invalid cell\n");
-            if (!srslte_cell_isvalid(&cell)) {
-              Error("SYNC:  Detected invalid cell\n");
-              phy_state = IDLE;
-              break;
-            }
-            if (set_cell()) {
-              set_sampling_rate();
-              phy_state = CELL_SELECT;
-            }
-            break;
-          case search::CELL_NOT_FOUND:
-            if (cell_search_in_progress) {
-              cell_search_inc();
-            }
             phy_state = IDLE;
             break;
-          default:
-            radio_error();
-            break;
           }
+          if (set_cell()) {
+            set_sampling_rate();
+            phy_state = CELL_SELECT;
+          }
+          break;
+        case search::CELL_NOT_FOUND:
+          cell_search_inc();
+          break;
+        default:
+          radio_error();
+          break;
         }
         break;
       case CELL_RESELECT:
@@ -569,7 +553,7 @@ void phch_recv::run_thread()
         switch (sfn_p.run_subframe(&cell, &tti))
         {
           case sfn_sync::SFN_FOUND:
-            if (!cell_search_in_progress) {
+            if (prev_state == CELL_SEARCH) {
               log_h->info("Sync OK. Camping on cell PCI=%d...\n", cell.id);
               phy_state = CELL_CAMP;
               rrc->cell_camping(earfcn[cur_earfcn_index], cell);
@@ -580,13 +564,8 @@ void phch_recv::run_thread()
             }
             break;
           case sfn_sync::TIMEOUT:
-            if (cell_search_in_progress) {
+            log_h->warning("SYNC:  Timeout while synchronizing SFN. Going back to cell search\n");
-              log_h->warning("SYNC:  Timeout while synchronizing SFN. Going back to cell search\n");
+            phy_state = CELL_SEARCH;
-              phy_state = CELL_SEARCH;
-            } else {
-              log_h->warning("SYNC:  Timeout while synchronizing SFN. Reselecting cell\n");
-              phy_state = CELL_SELECT;
-            }
             break;
           case sfn_sync::IDLE:
             break;
@@ -610,7 +589,6 @@ void phch_recv::run_thread()
 
             log_h->info("SYNC:  Measured OK. Camping on cell PCI=%d...\n", cell.id);
             phy_state = CELL_CAMP;
-            cell_search_in_progress = false;
             rrc->cell_camping(earfcn[cur_earfcn_index], cell, measure_p.rsrp());
             break;
           case measure::IDLE:
@@ -833,6 +811,7 @@ phch_recv::search::ret_code phch_recv::search::run(srslte_cell_t *cell)
   if (p->srate_mode != SRATE_FIND) {
     p->srate_mode = SRATE_FIND;
     p->radio_h->set_rx_srate(1.92e6);
+    Info("SYNC:  Setting Cell Search sampling rate\n");
   }
 
   /* Find a cell in the given N_id_2 or go through the 3 of them to find the strongest */
@@ -992,7 +971,7 @@ phch_recv::sfn_sync::ret_code phch_recv::sfn_sync::run_subframe(srslte_cell_t *c
       }
     }
   } else {
-    Debug("SYNC:  PSS/SSS not found...\n");
+    Info("SYNC:  PSS/SSS not found...\n");
   }
 
   cnt++;

srsue/src/phy/phy.cc

@@ -256,11 +256,6 @@ void phy::cell_search_start()
   sf_recv.cell_search_start();
 }
 
-void phy::cell_search_stop()
-{
-  sf_recv.cell_search_stop();
-}
-
 void phy::cell_search_next()
 {
   sf_recv.cell_search_next();

srsue/src/upper/nas.cc

@@ -161,14 +161,15 @@ void nas::plmn_found(LIBLTE_RRC_PLMN_IDENTITY_STRUCT plmn_id, uint16_t tracking_
 // RRC indicates that the UE has gone through all EARFCN and finished PLMN selection
 void nas::plmn_search_end() {
   if (known_plmns.size() > 0) {
-    nas_log->info("Could not find Home PLMN Id=%s, trying to connect to PLMN Id=%s\n",
+    if (home_plmn.mcc != known_plmns[0].mcc && home_plmn.mnc != known_plmns[0].mnc) {
-                  plmn_id_to_string(home_plmn).c_str(),
+      nas_log->info("Could not find Home PLMN Id=%s, trying to connect to PLMN Id=%s\n",
-                  plmn_id_to_string(known_plmns[0]).c_str());
+                    plmn_id_to_string(home_plmn).c_str(),
-
+                    plmn_id_to_string(known_plmns[0]).c_str());
-    nas_log->console("Could not find Home PLMN Id=%s, trying to connect to PLMN Id=%s\n",
+
-                     plmn_id_to_string(home_plmn).c_str(),
+      nas_log->console("Could not find Home PLMN Id=%s, trying to connect to PLMN Id=%s\n",
-                     plmn_id_to_string(known_plmns[0]).c_str());
+                       plmn_id_to_string(home_plmn).c_str(),
-
+                       plmn_id_to_string(known_plmns[0]).c_str());
+    }
     rrc->plmn_select(known_plmns[0]);
   } else {
     nas_log->info("Finished searching PLMN in current EARFCN set but no networks were found.\n");

srsue/src/upper/rrc.cc

@@ -212,10 +212,8 @@ void rrc::run_thread() {
         plmn_select_timeout++;
         if (plmn_select_timeout >= RRC_PLMN_SELECT_TIMEOUT) {
           rrc_log->info("RRC PLMN Search: timeout expired\n");
-          phy->cell_search_stop();
+          rrc_log->console("\nRRC PLMN Search: timeout expired.\n");
-          sleep(1);
+          state = RRC_STATE_IDLE;
-          rrc_log->console("\nRRC PLMN Search: timeout expired. Searching again\n");
-
         }
         break;
       case RRC_STATE_CELL_SELECTING:
@@ -236,14 +234,13 @@ void rrc::run_thread() {
           }
         }
         // Don't time out during reestablishment (T311 running)
-        if (!mac_timers->timer_get(t311)->is_running()) {
+        if (!mac_timers->timer_get(t311)->is_running() || !phy->sync_status()) {
           select_cell_timeout++;
           if (select_cell_timeout >= RRC_SELECT_CELL_TIMEOUT) {
             rrc_log->info("RRC Cell Selecting: timeout expired. Starting Cell Search...\n");
-            plmn_select_timeout = 0;
             select_cell_timeout = 0;
+            state = RRC_STATE_PLMN_START;
             serving_cell->in_sync = false;
-            phy->cell_search_start();
           }
         }
         break;
@@ -457,17 +454,30 @@ void rrc::plmn_select_rrc(LIBLTE_RRC_PLMN_IDENTITY_STRUCT plmn_id) {
   if (state == RRC_STATE_IDLE || state == RRC_STATE_CONNECTED || state == RRC_STATE_PLMN_SELECTION) {
     if (phy->sync_status() && selected_plmn_id.mcc == plmn_id.mcc && selected_plmn_id.mnc == plmn_id.mnc) {
       rrc_log->info("Already camping on selected PLMN, connecting...\n");
-      state = RRC_STATE_CELL_SELECTING;
-      select_cell_timeout = 0;
     } else {
-      rrc_log->info("PLMN Id=%s selected\n", plmn_id_to_string(plmn_id).c_str());
-      // Sort cells according to RSRP
-
       selected_plmn_id = plmn_id;
-      select_cell_timeout = 0;
 
-      state = RRC_STATE_CELL_SELECTING;
+      if (serving_cell->plmn_equals(selected_plmn_id)) {
+        phy->cell_select(serving_cell->get_earfcn(), serving_cell->phy_cell);
+      } else {
+        bool found = false;
+        for (uint32_t i=0;i<neighbour_cells.size() && !found;i++) {
+          if (neighbour_cells[i]->plmn_equals(selected_plmn_id)) {
+            rrc_log->info("PLMN Id=%s selected, PCI=%d\n", plmn_id_to_string(plmn_id).c_str(), neighbour_cells[i]->get_pci());
+            phy->cell_select(neighbour_cells[i]->get_earfcn(), neighbour_cells[i]->phy_cell);
+            found = true;
+          }
+        }
+        if (!found) {
+          rrc_log->warning("Could not find any cell for the selected PLMN\n");
+          state = RRC_STATE_IDLE;
+          return;
+        }
+      }
     }
+
+    state = RRC_STATE_CELL_SELECTING;
+    select_cell_timeout = 0;
   } else {
     rrc_log->warning("Requested PLMN select in incorrect state %s\n", rrc_state_text[state]);
   }
@@ -988,7 +998,6 @@ void rrc::send_con_restablish_request(LIBLTE_RRC_CON_REEST_REQ_CAUSE_ENUM cause,
       break;
     default:
       rrc_log->info("Unsupported integrity algorithm during reestablishment\n");
-      return;
   }
 
   // Prepare ConnectionRestalishmentRequest packet