UE RRC NR includes cell search in the initial cell selection procedure

srsue/hdr/stack/rrc_nr/rrc_nr.h

@@ -87,7 +87,6 @@ public:
   // PHY interface
   void in_sync() final;
   void out_of_sync() final;
-  void cell_search_found_cell(const cell_search_result_t& result) final{};
 
   // RLC interface
   void max_retx_attempted() final;
@@ -122,8 +121,9 @@ public:
   void rrc_release();
   bool configure_sk_counter(uint16_t sk_counter);
   bool is_config_pending();
+
   // STACK interface
-  void cell_search_completed(const rrc_interface_phy_lte::cell_search_ret_t& cs_ret, const phy_cell_t& found_cell);
+  void cell_search_found_cell(const rrc_interface_phy_nr::cell_search_result_t& result) final;
   void cell_select_completed(const cell_select_result_t& result) final;
   void set_phy_config_complete(bool status) final;
 

srsue/hdr/stack/rrc_nr/rrc_nr_procedures.h

@@ -32,7 +32,8 @@ public:
   srsran::proc_outcome_t step();
   cell_search_result_t   get_result() const { return cell_search_ret; }
   static const char*     name() { return "Cell Selection"; }
-  srsran::proc_outcome_t react(const bool& event);
+  srsran::proc_outcome_t react(const rrc_interface_phy_nr::cell_search_result_t& result);
+  srsran::proc_outcome_t react(const rrc_interface_phy_nr::cell_select_result_t& result);
   void                   then(const srsran::proc_result_t<cell_search_result_t>& proc_result) const;
 
 private:

srsue/hdr/stack/ue_stack_lte.h

@@ -125,7 +125,8 @@ public:
   void run_tti(uint32_t tti, uint32_t tti_jump) final;
 
   // RRC interface for NR PHY
-  void cell_search_found_cell(const cell_search_result_t& result) final {}
+  void cell_search_found_cell(const cell_search_result_t& result) final;
+  void cell_select_completed(const cell_select_result_t& result) final;
 
   // MAC Interface for NR PHY
   void tb_decoded(const uint32_t                              cc_idx,
@@ -168,7 +169,6 @@ public:
   void      reset_eps_bearers() final;
 
   srsran::ext_task_sched_handle get_task_sched() { return {&task_sched}; }
-  void                          cell_select_completed(const cell_select_result_t& result) override;
 
 private:
   void run_thread() final;

srsue/src/stack/rrc_nr/rrc_nr.cc

@@ -396,12 +396,8 @@ void rrc_nr::handle_sib1(const sib1_s& sib1)
   // Apply SSB Config
   fill_phy_ssb_cfg(sib1.serving_cell_cfg_common, &phy_cfg.ssb);
 
-  // Init cell selection
+  if (not phy->set_config(phy_cfg)) {
-  phy_interface_rrc_nr::cell_select_args_t cell_cfg = {};
+    logger.warning("Could not set phy config.");
-  cell_cfg.carrier                                  = phy_cfg.carrier;
-  cell_cfg.ssb_cfg                                  = phy_cfg.get_ssb_cfg();
-  if (not phy->start_cell_select(cell_cfg)) {
-    logger.warning("Could not set start cell select.");
     return;
   }
 }
@@ -1998,8 +1994,10 @@ void rrc_nr::ra_problem()
 void rrc_nr::release_pucch_srs() {}
 
 // STACK interface
-void rrc_nr::cell_search_completed(const rrc_interface_phy_lte::cell_search_ret_t& cs_ret, const phy_cell_t& found_cell)
+void rrc_nr::cell_search_found_cell(const rrc_interface_phy_nr::cell_search_result_t& result)
-{}
+{
+  cell_selector.trigger(result);
+}
 
 void rrc_nr::set_phy_config_complete(bool status)
 {
@@ -2021,10 +2019,7 @@ void rrc_nr::set_phy_config_complete(bool status)
 
 void rrc_nr::cell_select_completed(const rrc_interface_phy_nr::cell_select_result_t& result)
 {
-  if (not phy->set_config(phy_cfg)) {
+  cell_selector.trigger(result);
-    logger.warning("Could not set phy config.");
-    return;
-  }
 }
 
 } // namespace srsue

srsue/src/stack/rrc_nr/rrc_nr_procedures.cc

@@ -367,18 +367,21 @@ proc_outcome_t rrc_nr::cell_selection_proc::init()
   init_serv_cell = meas_cells.serving_cell().phy_cell;
 
   // TODO: add full cell selection
-  phy_interface_rrc_nr::cell_select_args_t cell_cfg = {};
+  // Start cell search
-  cell_cfg.carrier                                  = rrc_handle.phy_cfg.carrier;
+  phy_interface_rrc_nr::cell_search_args_t cs_args = {};
-  cell_cfg.ssb_cfg                                  = rrc_handle.phy_cfg.get_ssb_cfg();
+  cs_args.center_freq_hz                           = rrc_handle.phy_cfg.carrier.dl_center_frequency_hz;
-  rrc_handle.phy->start_cell_select(cell_cfg);
+  cs_args.ssb_freq_hz                              = rrc_handle.phy_cfg.carrier.ssb_center_freq_hz;
-
+  cs_args.ssb_scs                                  = rrc_handle.phy_cfg.ssb.scs;
-  // Skip cell selection if serving cell is suitable and there are no stronger neighbours in same earfcn
+  cs_args.ssb_pattern                              = rrc_handle.phy_cfg.ssb.pattern;
-  if (is_serv_cell_suitable()) {
+  cs_args.duplex_mode                              = rrc_handle.phy_cfg.duplex.mode;
-    Debug("Skipping cell selection procedure as there are no stronger neighbours in same EARFCN.");
+  if (not rrc_handle.phy->start_cell_search(cs_args)) {
-    return set_proc_complete();
+    Error("Could not set start cell search.");
+    return proc_outcome_t::error;
   }
 
-  return set_proc_complete();
+  state = search_state_t::cell_search;
+
+  return proc_outcome_t::yield;
 }
 
 proc_outcome_t rrc_nr::cell_selection_proc::step()
@@ -400,6 +403,61 @@ proc_outcome_t rrc_nr::cell_selection_proc::step()
   return proc_outcome_t::error;
 }
 
+proc_outcome_t rrc_nr::cell_selection_proc::react(const rrc_interface_phy_nr::cell_search_result_t& result)
+{
+  if (state != search_state_t::cell_search) {
+    Error("Cell search result received in wrong state");
+    return proc_outcome_t::error;
+  }
+
+  // Print result only if the cell is found
+  if (result.cell_found) {
+    // Convert Cell measurement in Text
+    std::array<char, 512> csi_info_str = {};
+    srsran_csi_meas_info_short(&result.measurements, csi_info_str.data(), (uint32_t)csi_info_str.size());
+
+    // Unpack MIB and convert to text
+    srsran_mib_nr_t       mib          = {};
+    std::array<char, 512> mib_info_str = {};
+    if (srsran_pbch_msg_nr_mib_unpack(&result.pbch_msg, &mib) == SRSASN_SUCCESS) {
+      // Convert to text
+      srsran_pbch_msg_nr_mib_info(&mib, mib_info_str.data(), (uint32_t)mib_info_str.size());
+    } else {
+      // It could be the PBCH does not carry MIB
+      strcpy(mib_info_str.data(), "No MIB found");
+    }
+
+    // Logs the PCI, cell measurements and decoded MIB
+    Info("Cell search found PCI=%d %s %s", result.pci, csi_info_str.data(), mib_info_str.data());
+  } else {
+    Info("Cell search did not find any cell");
+  }
+
+  // Transition to cell selection ignoring the cell search result
+  state = search_state_t::cell_selection;
+
+  phy_interface_rrc_nr::cell_select_args_t cs_args = {};
+  cs_args.carrier                                  = rrc_handle.phy_cfg.carrier;
+  cs_args.ssb_cfg                                  = rrc_handle.phy_cfg.get_ssb_cfg();
+
+  if (not rrc_handle.phy->start_cell_select(cs_args)) {
+    Error("Could not set start cell search.");
+    return proc_outcome_t::error;
+  }
+
+  return proc_outcome_t::yield;
+}
+
+proc_outcome_t rrc_nr::cell_selection_proc::react(const rrc_interface_phy_nr::cell_select_result_t& result)
+{
+  if (state != search_state_t::cell_selection) {
+    Error("Cell selection result received in wrong state");
+    return proc_outcome_t::error;
+  }
+
+  return set_proc_complete();
+}
+
 void rrc_nr::cell_selection_proc::then(const srsran::proc_result_t<cell_search_result_t>& proc_result) const
 {
   Info("Completed with %s.", proc_result.is_success() ? "success" : "failure");

srsue/src/stack/ue_stack_lte.cc

@@ -510,9 +510,13 @@ void ue_stack_lte::set_phy_config_complete(bool status)
   cfg_task_queue.push([this, status]() { rrc_nr.set_phy_config_complete(status); });
 }
 
+void ue_stack_lte::cell_search_found_cell(const cell_search_result_t& result)
+{
+  cfg_task_queue.push([this, result]() { rrc_nr.cell_search_found_cell(result); });
+}
 void ue_stack_lte::cell_select_completed(const rrc_interface_phy_nr::cell_select_result_t& result)
 {
-  rrc_nr.cell_select_completed(result);
+  cfg_task_queue.push([this, result]() { rrc_nr.cell_select_completed(result); });
 }
 
 } // namespace srsue

srsue/src/stack/ue_stack_nr.cc

@@ -202,6 +202,11 @@ void ue_stack_nr::set_phy_config_complete(bool status)
   sync_task_queue.push([this, status]() { rrc->set_phy_config_complete(status); });
 }
 
+void ue_stack_nr::cell_search_found_cell(const cell_search_result_t& result)
+{
+  sync_task_queue.push([this, result]() { rrc->cell_search_found_cell(result); });
+}
+
 void ue_stack_nr::cell_select_completed(const rrc_interface_phy_nr::cell_select_result_t& result)
 {
   sync_task_queue.push([this, result]() { rrc->cell_select_completed(result); });