units: added basic CU-CP unit implementation

Author: AlaiaL

apps/units/CMakeLists.txt

@@ -6,4 +6,5 @@
 # the distribution.
 #
 
+add_subdirectory(cu_cp)
 add_subdirectory(flexible_du)

apps/units/cu_cp/CMakeLists.txt

@@ -0,0 +1,15 @@
+#
+# Copyright 2021-2024 Software Radio Systems Limited
+#
+# By using this file, you agree to the terms and conditions set
+# forth in the LICENSE file which can be found at the top level of
+# the distribution.
+#
+
+set(SOURCES
+        cu_cp_application_unit_impl.cpp
+        cu_cp_unit_config_validator.cpp
+        cu_cp_unit_config_cli11_schema.cpp)
+
+add_library(srsran_cu_cp_app_unit STATIC ${SOURCES})
+target_include_directories(srsran_cu_cp_app_unit PRIVATE ${CMAKE_SOURCE_DIR})

apps/units/cu_cp/cu_cp_application_unit_impl.cpp

@@ -0,0 +1,31 @@
+/*
+ *
+ * Copyright 2021-2024 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#include "cu_cp_application_unit_impl.h"
+#include "cu_cp_logger_registrator.h"
+#include "cu_cp_unit_config_cli11_schema.h"
+#include "cu_cp_unit_config_validator.h"
+
+using namespace srsran;
+
+void cu_cp_application_unit_impl::on_parsing_configuration_registration(CLI::App& app)
+{
+  configure_cli11_with_cu_cp_unit_config_schema(app, unit_cfg);
+}
+
+bool cu_cp_application_unit_impl::on_configuration_validation() const
+{
+  return validate_cu_cp_unit_config(unit_cfg);
+}
+
+void cu_cp_application_unit_impl::on_loggers_registration()
+{
+  register_logs(unit_cfg.loggers);
+}

apps/units/cu_cp/cu_cp_application_unit_impl.h

@@ -0,0 +1,35 @@
+/*
+ *
+ * Copyright 2021-2024 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#pragma once
+
+#include "../application_unit.h"
+#include "cu_cp_unit_config.h"
+
+namespace srsran {
+
+/// CU-CP application unit implementation.
+class cu_cp_application_unit_impl : public application_unit
+{
+public:
+  // See interface for documentation.
+  void on_parsing_configuration_registration(CLI::App& app) override;
+
+  // See interface for documentation.
+  bool on_configuration_validation() const override;
+
+  // See interface for documentation.
+  void on_loggers_registration() override;
+
+private:
+  cu_cp_unit_config unit_cfg;
+};
+
+} // namespace srsran

apps/units/cu_cp/cu_cp_log_unit_config.h

@@ -0,0 +1,31 @@
+/*
+ *
+ * Copyright 2021-2024 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#pragma once
+
+#include <string>
+
+namespace srsran {
+
+/// Configuration of logging functionalities.
+struct cu_cp_log_unit_config {
+  std::string cu_level   = "warning";
+  std::string f1ap_level = "warning";
+  std::string pdcp_level = "warning";
+  std::string rrc_level  = "warning";
+  std::string ngap_level = "warning";
+  std::string sec_level  = "warning";
+  /// Maximum number of bytes to write when dumping hex arrays.
+  int hex_max_size = 0;
+  /// Enable JSON generation for the F1AP Tx and Rx PDUs.
+  bool f1ap_json_enabled = false;
+};
+
+} // namespace srsran

apps/units/cu_cp/cu_cp_logger_registrator.h

@@ -0,0 +1,48 @@
+/*
+ *
+ * Copyright 2021-2024 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#pragma once
+
+#include "cu_cp_log_unit_config.h"
+#include "srsran/srslog/srslog.h"
+
+namespace srsran {
+
+/// Registers the CU-CP loggers in the logger service.
+inline void register_logs(const cu_cp_log_unit_config& log_cfg)
+{
+  for (const auto& id : {"CU-CP", "CU-UEMNG", "CU-CP-E1"}) {
+    auto& cu_cp_logger = srslog::fetch_basic_logger(id, false);
+    cu_cp_logger.set_level(srslog::str_to_basic_level(log_cfg.cu_level));
+    cu_cp_logger.set_hex_dump_max_size(log_cfg.hex_max_size);
+  }
+
+  auto& pdcp_logger = srslog::fetch_basic_logger("PDCP", false);
+  pdcp_logger.set_level(srslog::str_to_basic_level(log_cfg.pdcp_level));
+  pdcp_logger.set_hex_dump_max_size(log_cfg.hex_max_size);
+
+  auto& rrc_logger = srslog::fetch_basic_logger("RRC", false);
+  rrc_logger.set_level(srslog::str_to_basic_level(log_cfg.rrc_level));
+  rrc_logger.set_hex_dump_max_size(log_cfg.hex_max_size);
+
+  auto& cu_f1ap_logger = srslog::fetch_basic_logger("CU-CP-F1", false);
+  cu_f1ap_logger.set_level(srslog::str_to_basic_level(log_cfg.f1ap_level));
+  cu_f1ap_logger.set_hex_dump_max_size(log_cfg.hex_max_size);
+
+  auto& ngap_logger = srslog::fetch_basic_logger("NGAP", false);
+  ngap_logger.set_level(srslog::str_to_basic_level(log_cfg.ngap_level));
+  ngap_logger.set_hex_dump_max_size(log_cfg.hex_max_size);
+
+  auto& sec_logger = srslog::fetch_basic_logger("SEC", false);
+  sec_logger.set_level(srslog::str_to_basic_level(log_cfg.sec_level));
+  sec_logger.set_hex_dump_max_size(log_cfg.hex_max_size);
+}
+
+} // namespace srsran

apps/units/cu_cp/cu_cp_unit_config.h

@@ -0,0 +1,102 @@
+/*
+ *
+ * Copyright 2021-2024 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#pragma once
+
+#include "cu_cp_log_unit_config.h"
+#include "srsran/adt/optional.h"
+#include "srsran/ran/gnb_id.h"
+#include "srsran/ran/nr_band.h"
+#include "srsran/ran/pci.h"
+#include <vector>
+
+namespace srsran {
+
+/// Report configuration, for now only supporting the A3 event.
+struct cu_cp_report_unit_config {
+  unsigned           report_cfg_id;
+  std::string        report_type;
+  optional<unsigned> report_interval_ms;
+  std::string        a3_report_type;
+  optional<int> a3_offset_db; ///< [-30..30] Note the actual value is field value * 0.5 dB. E.g. putting a value of -6
+                              ///< here results in -3dB offset.
+  optional<unsigned> a3_hysteresis_db;
+  optional<unsigned> a3_time_to_trigger_ms;
+};
+
+struct cu_cp_neighbor_cell_unit_config_item {
+  uint64_t              nr_cell_id;     ///< Cell id.
+  std::vector<uint64_t> report_cfg_ids; ///< Report config ids
+};
+
+/// Each item describes the relationship between one cell to all other cells.
+struct cu_cp_cell_unit_config_item {
+  uint64_t           nr_cell_id; ///< Cell id.
+  optional<unsigned> periodic_report_cfg_id;
+
+  // These parameters must only be set for external cells
+  // TODO: Add optional SSB parameters.
+  optional<unsigned> gnb_id_bit_length; ///< gNodeB identifier bit length.
+  optional<pci_t>    pci;               ///< PCI.
+  optional<nr_band>  band;              ///< NR band.
+  optional<unsigned> ssb_arfcn;         ///< SSB ARFCN.
+  optional<unsigned> ssb_scs;           ///< SSB subcarrier spacing.
+  optional<unsigned> ssb_period;        ///< SSB period.
+  optional<unsigned> ssb_offset;        ///< SSB offset.
+  optional<unsigned> ssb_duration;      ///< SSB duration.
+
+  std::vector<cu_cp_neighbor_cell_unit_config_item> ncells; ///< Vector of cells that are a neighbor of this cell.
+};
+
+/// All mobility related configuration parameters.
+struct mobility_unit_config {
+  std::vector<cu_cp_cell_unit_config_item> cells;          ///< List of all cells known to the CU-CP.
+  std::vector<cu_cp_report_unit_config>    report_configs; ///< Report config.
+  bool trigger_handover_from_measurements = false; ///< Whether to start HO if neighbor cell measurements arrive.
+};
+
+/// RRC specific configuration parameters.
+struct rrc_appconfig {
+  bool     force_reestablishment_fallback = false;
+  unsigned rrc_procedure_timeout_ms       = 720; ///< Timeout for RRC procedures (2 * default SRB maxRetxThreshold *
+                                                 ///< t-PollRetransmit = 2 * 8 * 45ms = 720ms, see TS 38.331 Sec 9.2.1).
+};
+
+/// Security configuration parameters.
+struct security_unit_config {
+  std::string integrity_protection       = "not_needed";
+  std::string confidentiality_protection = "required";
+  std::string nea_preference_list        = "nea0,nea2,nea1,nea3";
+  std::string nia_preference_list        = "nia2,nia1,nia3";
+};
+
+/// F1AP-CU configuration parameters.
+struct f1ap_cu_unit_config {
+  /// Timeout for the UE context setup procedure in milliseconds.
+  unsigned ue_context_setup_timeout = 1000;
+};
+
+/// CU-CP application configuration.
+struct cu_cp_unit_config {
+  // :TODO: not sure if gNB id should be here.
+  gnb_id_t gnb_id = {411, 22};
+  // :TODO: AMF should be here too?
+  uint16_t              max_nof_dus               = 6;
+  uint16_t              max_nof_cu_ups            = 6;
+  int                   inactivity_timer          = 5; // in seconds
+  unsigned              pdu_session_setup_timeout = 3; // in seconds (must be larger than T310)
+  mobility_unit_config  mobility_config;
+  rrc_appconfig         rrc_config;
+  security_unit_config  security_config;
+  f1ap_cu_unit_config   f1ap_config;
+  cu_cp_log_unit_config loggers;
+};
+
+} // namespace srsran