srsdu: allow 2.5 ms scheduling request period

Author: joaquim-srs

apps/units/flexible_du/du_high/du_high_config.h

@@ -218,8 +218,8 @@ struct du_high_unit_pucch_config {
 
   /// \brief \c SR period in milliseconds.
   /// Among all values given in \c periodicityAndOffset, part of \c \SchedulingRequestResourceConfig, TS 38.331,
-  /// these are the only ones supported. Values: {1, 2, 4, 8, 10, 16, 20, 40, 80, 160, 320}.
-  unsigned sr_period_msec = 20;
+  /// these are the only ones supported. Values: {1, 2, 2.5, 4, 5, 8, 10, 16, 20, 40, 80, 160, 320}.
+  float sr_period_msec = 20.0F;
 
   /// PUCCH F1 resource parameters.
   /// Number of symbols for PUCCH Format 1. Values {4, 14}.

apps/units/flexible_du/du_high/du_high_config_cli11_schema.cpp

@@ -698,7 +698,7 @@ static void configure_cli11_pucch_args(CLI::App& app, du_high_unit_pucch_config&
       });
   add_option(app, "--sr_period_ms", pucch_params.sr_period_msec, "SR period in msec")
       ->capture_default_str()
-      ->check(CLI::IsMember({1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 160, 320}));
+      ->check(CLI::IsMember({1.0F, 2.0F, 2.5F, 4.0F, 5.0F, 8.0F, 10.0F, 16.0F, 20.0F, 40.0F, 80.0F, 160.0F, 320.0F}));
   add_option(app,
              "--f1_nof_ue_res_harq",
              pucch_params.nof_ue_pucch_f1_res_harq,

apps/units/flexible_du/du_high/du_high_config_translators.cpp

@@ -583,8 +583,8 @@ std::vector<du_cell_config> srsran::generate_du_cell_config(const du_high_unit_c
     if (sr_cng.empty()) {
       sr_cng.emplace_back(scheduling_request_resource_config{});
     }
-    sr_cng.front().period = static_cast<sr_periodicity>(get_nof_slots_per_subframe(base_cell.common_scs) *
-                                                        base_cell.pucch_cfg.sr_period_msec);
+    sr_cng.front().period = static_cast<sr_periodicity>(
+        static_cast<unsigned>(get_nof_slots_per_subframe(base_cell.common_scs) * base_cell.pucch_cfg.sr_period_msec));
 
     // If any dependent parameter needs to be updated, this is the place.
     config_helpers::compute_nof_sr_csi_pucch_res(du_pucch_cfg,

apps/units/flexible_du/du_high/du_high_config_validator.cpp

@@ -390,8 +390,18 @@ static bool validate_pucch_cell_unit_config(const du_high_unit_base_cell_config&
     return false;
   }
 
-  static constexpr std::array<unsigned, 11> valid_sr_period_slots{1, 2, 4, 8, 10, 16, 20, 40, 80, 160, 320};
-  const unsigned sr_period_slots = get_nof_slots_per_subframe(scs_common) * pucch_cfg.sr_period_msec;
+  static constexpr std::array<unsigned, 12> valid_sr_period_slots{1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 160, 320};
+  const auto sr_period_slots = static_cast<unsigned>(get_nof_slots_per_subframe(scs_common) * pucch_cfg.sr_period_msec);
+
+  // Check that the SR period in milliseconds leads to an integer number of slots.
+  if (get_nof_slots_per_subframe(scs_common) * pucch_cfg.sr_period_msec != static_cast<float>(sr_period_slots)) {
+    fmt::print("SR period (i.e., {}ms) times the number of slots per subframe (i.e., {}) must be an integer number of "
+               "slots.\n",
+               pucch_cfg.sr_period_msec,
+               get_nof_slots_per_subframe(scs_common));
+    return false;
+  }
+
   if (std::find(valid_sr_period_slots.begin(), valid_sr_period_slots.end(), sr_period_slots) ==
       valid_sr_period_slots.end()) {
     fmt::print("SR period of {}ms is not valid for {}kHz SCS.\n", pucch_cfg.sr_period_msec, scs_to_khz(scs_common));

include/srsran/du/du_update_config_helpers.h

@@ -36,7 +36,7 @@ unsigned compute_prach_frequency_start(const pucch_builder_params& user_params,
 /// \param csi_period_msec CSI period in milliseconds.
 void compute_nof_sr_csi_pucch_res(pucch_builder_params&   user_params,
                                   unsigned                max_pucch_grants_per_slot,
-                                  unsigned                sr_period_msec,
+                                  float                   sr_period_msec,
                                   std::optional<unsigned> csi_period_msec);
 
 } // namespace config_helpers

lib/du/du_update_config_helpers.cpp

@@ -87,7 +87,7 @@ unsigned srsran::config_helpers::compute_prach_frequency_start(const pucch_build
 
 void srsran::config_helpers::compute_nof_sr_csi_pucch_res(pucch_builder_params&   user_params,
                                                           unsigned                max_pucch_grants_per_slot,
-                                                          unsigned                sr_period_msec,
+                                                          float                   sr_period_msec,
                                                           std::optional<unsigned> csi_period_msec)
 {
   // [Implementation-defined] In the following, we compute the estimated number of PUCCH resources that are needed for