du: assign one extra PUCCH resource for SR signalling.

Author: frankist

lib/du_manager/ran_resource_management/du_pucch_resource_manager.cpp

@@ -50,7 +50,8 @@ du_pucch_resource_manager::du_pucch_resource_manager(span<const du_cell_config>
           continue;
         }
       }
-      cell.sr_offset_free_list.push_back(offset);
+      cell.sr_offset_free_list.emplace_back(default_pucch_cfg.sr_res_list[0].pucch_res_id - 1, offset);
+      cell.sr_offset_free_list.emplace_back(default_pucch_cfg.sr_res_list[0].pucch_res_id, offset);
     }
 
     for (unsigned offset = 0; offset != csi_period; ++offset) {
@@ -79,14 +80,13 @@ bool du_pucch_resource_manager::alloc_resources(cell_group_config& cell_grp_cfg)
     if (free_sr_list.empty()) {
       break;
     }
-    sr_res_list[i].offset = free_sr_list.back();
+    sr_res_list[i].pucch_res_id = free_sr_list.back().first;
+    sr_res_list[i].offset       = free_sr_list.back().second;
     free_sr_list.pop_back();
   }
   if (i != sr_res_list.size()) {
     // Allocation failed. Return resources back to the pool.
-    for (unsigned j = 0; j != i; ++j) {
-      free_sr_list.push_back(sr_res_list[i].offset);
-    }
+    dealloc_resources(cell_grp_cfg);
     return false;
   }
 
@@ -98,6 +98,7 @@ bool du_pucch_resource_manager::alloc_resources(cell_group_config& cell_grp_cfg)
     auto& free_csi_list = cells[cell_grp_cfg.cells[0].serv_cell_cfg.cell_index].csi_offset_free_list;
     if (free_csi_list.empty()) {
       // Allocation failed.
+      dealloc_resources(cell_grp_cfg);
       return false;
     }
     target_csi_cfg.report_slot_offset = free_csi_list.back();
@@ -110,7 +111,7 @@ bool du_pucch_resource_manager::alloc_resources(cell_group_config& cell_grp_cfg)
 void du_pucch_resource_manager::dealloc_resources(cell_group_config& cell_grp_cfg)
 {
   for (auto& sr : cell_grp_cfg.cells[0].serv_cell_cfg.ul_config->init_ul_bwp.pucch_cfg->sr_res_list) {
-    cells[cell_grp_cfg.cells[0].serv_cell_cfg.cell_index].sr_offset_free_list.push_back(sr.offset);
+    cells[cell_grp_cfg.cells[0].serv_cell_cfg.cell_index].sr_offset_free_list.emplace_back(sr.pucch_res_id, sr.offset);
   }
   if (cell_grp_cfg.cells[0].serv_cell_cfg.csi_meas_cfg.has_value()) {
     auto& target_csi_cfg = srsran::variant_get<csi_report_config::periodic_or_semi_persistent_report_on_pucch>(

lib/du_manager/ran_resource_management/du_pucch_resource_manager.h

@@ -39,8 +39,9 @@ class du_pucch_resource_manager
   const optional<csi_report_config> default_csi_report_cfg;
 
   struct cell_resource_context {
-    /// Pool of PUCCH SR offsets currently available to be allocated to UEs.
-    std::vector<unsigned> sr_offset_free_list;
+    /// \brief Pool of PUCCH SR offsets currently available to be allocated to UEs. Each element is represented by a
+    /// pair (pucch_resource_id, slot_offset).
+    std::vector<std::pair<unsigned, unsigned>> sr_offset_free_list;
     /// Pool of PUCCH CSI offsets currently available to be allocated to UEs.
     std::vector<unsigned> csi_offset_free_list;
   };

lib/scheduler/config/serving_cell_config_factory.cpp

@@ -446,13 +446,13 @@ uplink_config srsran::config_helpers::make_default_ue_uplink_config(const cell_c
 
   // TODO: add more PUCCH resources.
 
-  // >>> SR Resource.
-  const unsigned pucch_sr_res_id = pucch_cfg.pucch_res_list.size() - 1;
-  pucch_cfg.sr_res_list.push_back(scheduling_request_resource_config{.sr_res_id    = 1,
-                                                                     .sr_id        = uint_to_sched_req_id(0),
-                                                                     .period       = sr_periodicity::sl_40,
-                                                                     .offset       = 0,
-                                                                     .pucch_res_id = pucch_sr_res_id});
+  // >>> SR Resources.
+  pucch_cfg.sr_res_list.push_back(
+      scheduling_request_resource_config{.sr_res_id    = 1,
+                                         .sr_id        = uint_to_sched_req_id(0),
+                                         .period       = sr_periodicity::sl_40,
+                                         .offset       = 0,
+                                         .pucch_res_id = (unsigned)pucch_cfg.pucch_res_list.size() - 1U});
 
   pucch_cfg.format_1_common_param.emplace();
   pucch_cfg.format_2_common_param.emplace(
@@ -579,9 +579,9 @@ csi_report_config srsran::config_helpers::make_default_csi_report_config(const c
 
   csi_report_config::periodic_or_semi_persistent_report_on_pucch report_cfg_type{};
   report_cfg_type.report_type = csi_report_config::periodic_or_semi_persistent_report_on_pucch::report_type_t::periodic;
-  csi_resource_periodicity csi_rs_period = get_max_csi_rs_period(params);
-  // Set CSI report period equal to the CSI-RS period. No point in reporting more often than we get CSI-RS.
-  report_cfg_type.report_slot_period = static_cast<csi_report_periodicity>(std::min((unsigned)csi_rs_period, 320U));
+  // Note: the period for reporting is directly proportional to the number of CSI-RS resources available, and,
+  // therefore, to the number of UEs supported by the gNB.
+  report_cfg_type.report_slot_period = csi_report_periodicity::slots80;
   report_cfg_type.report_slot_offset = 9;
   report_cfg_type.pucch_csi_res_list.push_back(
       csi_report_config::pucch_csi_resource{.ul_bwp = to_bwp_id(0), .pucch_res_id = 9});

tests/unittests/du_manager/du_ran_resource_manager_test.cpp

@@ -91,20 +91,21 @@ TEST_P(du_ran_resource_manager_tester, when_multiple_ues_are_created_then_they_u
 {
   unsigned sr_period            = get_config_sr_period();
   unsigned slots_per_frame      = NOF_SUBFRAMES_PER_FRAME * get_nof_slots_per_subframe(cell_cfg_list[0].scs_common);
-  unsigned nof_avail_sr_offsets = sr_period;
+  unsigned nof_avail_sr_offsets = sr_period * 2;
   if (cell_cfg_list[0].tdd_ul_dl_cfg_common.has_value()) {
     nof_avail_sr_offsets = 0;
     for (unsigned i = 0; i != sr_period; ++i) {
       if (has_active_tdd_ul_symbols(*cell_cfg_list[0].tdd_ul_dl_cfg_common, i % slots_per_frame)) {
-        nof_avail_sr_offsets++;
+        nof_avail_sr_offsets += 2;
       }
     }
   }
+  du_ue_index_t next_ue_index = to_du_ue_index(0);
 
-  // > Created UEs have unique SR offsets.
-  std::set<unsigned> sr_offsets;
+  // > Created UEs have unique (PUCCH resource, SR offset) pairs.
+  std::set<std::pair<unsigned, unsigned>> sr_offsets;
   for (unsigned i = 0; i != nof_avail_sr_offsets; ++i) {
-    ue_ran_resource_configurator& ue_res = create_ue(to_du_ue_index(i));
+    ue_ran_resource_configurator& ue_res = create_ue(next_ue_index);
     ASSERT_FALSE(ue_res.empty());
     const auto& sr_res_list = ue_res->cells[0].serv_cell_cfg.ul_config->init_ul_bwp.pucch_cfg->sr_res_list;
     ASSERT_FALSE(sr_res_list.empty());
@@ -113,13 +114,14 @@ TEST_P(du_ran_resource_manager_tester, when_multiple_ues_are_created_then_they_u
       ASSERT_TRUE(
           has_active_tdd_ul_symbols(*cell_cfg_list[0].tdd_ul_dl_cfg_common, sr_res_list[0].offset % slots_per_frame));
     }
-    ASSERT_EQ(sr_offsets.count(sr_res_list[0].offset), 0);
-    sr_offsets.insert(sr_res_list[0].offset);
+    ASSERT_EQ(sr_offsets.count(std::make_pair(sr_res_list[0].pucch_res_id, sr_res_list[0].offset)), 0);
+    sr_offsets.insert(std::make_pair(sr_res_list[0].pucch_res_id, sr_res_list[0].offset));
+    next_ue_index = to_du_ue_index((unsigned)next_ue_index + 1);
   }
 
   {
     // > No more SR offsets available. UE Resource Allocation fails.
-    ue_ran_resource_configurator& empty_ue_res = create_ue(to_du_ue_index(sr_period));
+    ue_ran_resource_configurator& empty_ue_res = create_ue(next_ue_index);
     ASSERT_TRUE(empty_ue_res.empty());
     ues.erase(to_du_ue_index(sr_period));
   }
@@ -129,7 +131,8 @@ TEST_P(du_ran_resource_manager_tester, when_multiple_ues_are_created_then_they_u
   unsigned      rem_sr_offset =
       ues[ue_idx_to_rem]->cells[0].serv_cell_cfg.ul_config->init_ul_bwp.pucch_cfg->sr_res_list[0].offset;
   ues.erase(ue_idx_to_rem);
-  ue_ran_resource_configurator& ue_res = create_ue(to_du_ue_index(sr_period + 1));
+  next_ue_index                        = to_du_ue_index((unsigned)next_ue_index + 1);
+  ue_ran_resource_configurator& ue_res = create_ue(next_ue_index);
   ASSERT_FALSE(ue_res.empty());
   ASSERT_EQ(rem_sr_offset, ue_res->cells[0].serv_cell_cfg.ul_config->init_ul_bwp.pucch_cfg->sr_res_list[0].offset);
 }