refactor RLC UM and add NR receiver

lib/include/srslte/interfaces/rrc_interface_types.h

@@ -257,21 +257,22 @@ struct rlc_um_nr_config_t {
   rlc_um_nr_sn_size_t sn_field_length; // Number of bits used for sequence number
   uint32_t            UM_Window_Size;
   uint32_t            mod; // Rx/Tx counter modulus
+  int32_t             t_reassembly_ms; // Timer used by rx to detect PDU loss (ms)
 };
 
 #define RLC_TX_QUEUE_LEN (128)
 
-enum class rlc_type_t { lte, nr, nulltype };
+enum class srslte_rat_t { lte, nr, nulltype };
-inline std::string to_string(const rlc_type_t& type)
+inline std::string to_string(const srslte_rat_t& type)
 {
   constexpr static const char* options[] = {"LTE", "NR"};
-  return enum_to_text(options, (uint32_t)rlc_type_t::nulltype, (uint32_t)type);
+  return enum_to_text(options, (uint32_t)srslte_rat_t::nulltype, (uint32_t)type);
 }
 
 class rlc_config_t
 {
 public:
-  rlc_type_t         type;
+  srslte_rat_t          rat;
   rlc_mode_t       rlc_mode;
   rlc_am_config_t  am;
   rlc_um_config_t  um;
@@ -279,7 +280,7 @@ public:
   uint32_t           tx_queue_length;
 
   rlc_config_t() :
-    type(rlc_type_t::lte),
+    rat(srslte_rat_t::lte),
     rlc_mode(rlc_mode_t::tm),
     am(),
     um(),
@@ -290,7 +291,7 @@ public:
   static rlc_config_t mch_config()
   {
     rlc_config_t cfg          = {};
-    cfg.type                  = rlc_type_t::lte;
+    cfg.rat                   = srslte_rat_t::lte;
     cfg.rlc_mode              = rlc_mode_t::um;
     cfg.um.t_reordering       = 45;
     cfg.um.rx_sn_field_length = rlc_umd_sn_size_t::size5bits;
@@ -309,7 +310,7 @@ public:
     }
     // SRB1 and SRB2 are AM
     rlc_config_t rlc_cfg         = {};
-    rlc_cfg.type                 = rlc_type_t::lte;
+    rlc_cfg.rat                  = srslte_rat_t::lte;
     rlc_cfg.rlc_mode             = rlc_mode_t::am;
     rlc_cfg.am.t_poll_retx       = 45;
     rlc_cfg.am.poll_pdu          = -1;
@@ -322,7 +323,7 @@ public:
   static rlc_config_t default_rlc_um_config(uint32_t sn_size = 10)
   {
     rlc_config_t cnfg    = {};
-    cnfg.type            = rlc_type_t::lte;
+    cnfg.rat             = srslte_rat_t::lte;
     cnfg.rlc_mode        = rlc_mode_t::um;
     cnfg.um.t_reordering = 5;
     if (sn_size == 10) {
@@ -345,7 +346,7 @@ public:
   static rlc_config_t default_rlc_am_config()
   {
     rlc_config_t rlc_cnfg         = {};
-    rlc_cnfg.type                 = rlc_type_t::lte;
+    rlc_cnfg.rat                  = srslte_rat_t::lte;
     rlc_cnfg.rlc_mode             = rlc_mode_t::am;
     rlc_cnfg.am.t_reordering      = 5;
     rlc_cnfg.am.t_status_prohibit = 5;
@@ -358,7 +359,7 @@ public:
   static rlc_config_t default_rlc_um_nr_config(uint32_t sn_size = 6)
   {
     rlc_config_t cnfg = {};
-    cnfg.type         = rlc_type_t::nr;
+    cnfg.rat          = srslte_rat_t::nr;
     cnfg.rlc_mode     = rlc_mode_t::um;
     if (sn_size == 6) {
       cnfg.um_nr.sn_field_length = rlc_um_nr_sn_size_t::size6bits;
@@ -371,6 +372,7 @@ public:
     } else {
       return {};
     }
+    cnfg.um_nr.t_reassembly_ms = 5; // lowest non-zero value
     return cnfg;
   }
 };

lib/include/srslte/upper/rlc_am_lte.h

@@ -86,8 +86,7 @@ public:
   int      read_pdu(uint8_t *payload, uint32_t nof_bytes);
   void     write_pdu(uint8_t *payload, uint32_t nof_bytes);
 
-  uint32_t get_num_tx_bytes();
+  rlc_bearer_metrics_t get_metrics();
-  uint32_t get_num_rx_bytes();
   void reset_metrics();
 
 private:
@@ -283,6 +282,8 @@ private:
   // Rx and Tx objects
   rlc_am_lte_tx tx;
   rlc_am_lte_rx rx;
+
+  rlc_bearer_metrics_t metrics = {};
 };
 
 /****************************************************************************

lib/include/srslte/upper/rlc_common.h

@@ -23,6 +23,7 @@
 #define SRSLTE_RLC_COMMON_H
 
 #include "srslte/common/block_queue.h"
+#include "srslte/upper/rlc_metrics.h"
 #include <stdlib.h>
 
 namespace srslte {
@@ -64,6 +65,12 @@ inline std::string to_string(const rlc_nr_si_field_t& si)
   return enum_to_text(options, (uint32_t)rlc_nr_si_field_t::nulltype, (uint32_t)si);
 }
 
+inline std::string to_string_short(const rlc_nr_si_field_t& si)
+{
+  constexpr static const char* options[] = {"full", "first", "last", "middle"};
+  return enum_to_text(options, (uint32_t)rlc_nr_si_field_t::nulltype, (uint32_t)si);
+}
+
 static inline uint8_t operator&(rlc_nr_si_field_t lhs, int rhs)
 {
   return static_cast<uint8_t>(static_cast<std::underlying_type<rlc_nr_si_field_t>::type>(lhs) &
@@ -91,7 +98,7 @@ typedef struct {
   rlc_nr_si_field_t   si;      // Segmentation info
   rlc_um_nr_sn_size_t sn_size; // Sequence number size (6 or 12 bits)
   uint16_t            sn;      // Sequence number
-  uint16_t            so;      // Sequence offset
+  uint16_t            so;      // Segment offset
 } rlc_um_nr_pdu_header_t;
 
 // AMD PDU Header
@@ -137,9 +144,10 @@ struct rlc_amd_pdu_header_t{
     lsf  = h.lsf;
     so   = h.so;
     N_li = h.N_li;
-    for(uint32_t i=0;i<h.N_li;i++)
+    for (uint32_t i = 0; i < h.N_li; i++) {
       li[i] = h.li[i];
     }
+  }
 };
 
 // NACK helper
@@ -215,8 +223,7 @@ public:
   virtual rlc_mode_t    get_mode() = 0;
   virtual uint32_t      get_bearer() = 0;
 
-  virtual uint32_t get_num_tx_bytes() = 0;
+  virtual rlc_bearer_metrics_t get_metrics()   = 0;
-  virtual uint32_t get_num_rx_bytes() = 0;
   virtual void reset_metrics() = 0;
 
   // PDCP interface

lib/include/srslte/upper/rlc_metrics.h

@@ -26,12 +26,22 @@
 
 namespace srslte {
 
-struct rlc_metrics_t
+typedef struct {
-{
+  uint32_t num_tx_sdus;
-  float dl_tput_mbps[SRSLTE_N_RADIO_BEARERS];
+  uint32_t num_rx_sdus;
-  float ul_tput_mbps[SRSLTE_N_RADIO_BEARERS];
+  uint32_t num_tx_pdus;
-  float dl_tput_mrb_mbps[SRSLTE_N_MCH_LCIDS];
+  uint32_t num_rx_pdus;
-};
+  uint64_t num_tx_bytes;
+  uint64_t num_rx_bytes;
+
+  uint32_t num_lost_pdus;
+  uint32_t num_dropped_sdus;
+} rlc_bearer_metrics_t;
+
+typedef struct {
+  rlc_bearer_metrics_t bearer[SRSLTE_N_RADIO_BEARERS];
+  rlc_bearer_metrics_t mrb_bearer[SRSLTE_N_MCH_LCIDS];
+} rlc_metrics_t;
 
 } // namespace srslte
 

lib/include/srslte/upper/rlc_tm.h

@@ -49,8 +49,7 @@ public:
   rlc_mode_t    get_mode();
   uint32_t      get_bearer();
 
-  uint32_t get_num_tx_bytes();
+  rlc_bearer_metrics_t get_metrics();
-  uint32_t get_num_rx_bytes();
   void reset_metrics();
 
   // PDCP interface
@@ -71,8 +70,7 @@ private:
 
   bool tx_enabled = true;
 
-  uint32_t num_tx_bytes = 0;
+  rlc_bearer_metrics_t metrics = {};
-  uint32_t num_rx_bytes = 0;
 
   // Thread-safe queues for MAC messages
   rlc_tx_queue    ul_queue;

lib/include/srslte/upper/rlc_um.h

@@ -1,281 +0,0 @@
-/*
- * Copyright 2013-2019 Software Radio Systems Limited
- *
- * This file is part of srsLTE.
- *
- * srsLTE is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of
- * the License, or (at your option) any later version.
- *
- * srsLTE is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Affero General Public License for more details.
- *
- * A copy of the GNU Affero General Public License can be found in
- * the LICENSE file in the top-level directory of this distribution
- * and at http://www.gnu.org/licenses/.
- *
- */
-
-#ifndef SRSLTE_RLC_UM_H
-#define SRSLTE_RLC_UM_H
-
-#include "srslte/common/buffer_pool.h"
-#include "srslte/common/common.h"
-#include "srslte/common/log.h"
-#include "srslte/interfaces/ue_interfaces.h"
-#include "srslte/upper/rlc_common.h"
-#include "srslte/upper/rlc_tx_queue.h"
-#include <map>
-#include <mutex>
-#include <pthread.h>
-#include <queue>
-
-namespace srslte {
-
-struct rlc_umd_pdu_t{
-  rlc_umd_pdu_header_t  header;
-  unique_byte_buffer_t  buf;
-};
-
-typedef struct {
-  rlc_um_nr_pdu_header_t  header;
-  unique_byte_buffer_t    buf;
-} rlc_umd_pdu_nr_t;
-
-class rlc_um
-    :public rlc_common
-{
-public:
-  rlc_um(srslte::log*               log_,
-         uint32_t                   lcid_,
-         srsue::pdcp_interface_rlc* pdcp_,
-         srsue::rrc_interface_rlc*  rrc_,
-         srslte::timer_handler*     timers_);
-  ~rlc_um();
-  bool configure(rlc_config_t cnfg);
-  void reestablish();
-  void stop();
-  void empty_queue();
-  bool is_mrb();
-
-  rlc_mode_t    get_mode();
-  uint32_t      get_bearer();
-
-  // PDCP interface
-  void write_sdu(unique_byte_buffer_t sdu, bool blocking = true);
-
-  // MAC interface
-  bool     has_data();
-  uint32_t get_buffer_state();
-  int      read_pdu(uint8_t *payload, uint32_t nof_bytes);
-  void     write_pdu(uint8_t *payload, uint32_t nof_bytes);
-  int get_increment_sequence_num();
-
-  uint32_t get_num_tx_bytes();
-  uint32_t get_num_rx_bytes();
-  void reset_metrics();
-
-private:
-  // Transmitter sub-class base
-  class rlc_um_tx_base
-  {
-  public:
-    rlc_um_tx_base(srslte::log* log_);
-    virtual ~rlc_um_tx_base();
-    virtual bool configure(rlc_config_t cfg, std::string rb_name) = 0;
-    int  build_data_pdu(uint8_t *payload, uint32_t nof_bytes);
-    void stop();
-    void reestablish();
-    void empty_queue();
-    void     write_sdu(unique_byte_buffer_t sdu);
-    void     try_write_sdu(unique_byte_buffer_t sdu);
-    uint32_t get_num_tx_bytes();
-    void reset_metrics();
-    bool has_data();
-    uint32_t get_buffer_state();
-
-  protected:
-    byte_buffer_pool*       pool = nullptr;
-    srslte::log*            log  = nullptr;
-    std::string             rb_name;
-
-    /****************************************************************************
-     * Configurable parameters
-     * Ref: 3GPP TS 36.322 v10.0.0 Section 7
-     ***************************************************************************/
-    rlc_config_t cfg = {};
-
-    // TX SDU buffers
-    rlc_tx_queue            tx_sdu_queue;
-    unique_byte_buffer_t    tx_sdu;
-
-    // Mutexes
-    std::mutex mutex;
-
-    bool tx_enabled = false;
-
-    uint32_t num_tx_bytes = 0;
-
-    virtual int build_data_pdu(unique_byte_buffer_t pdu, uint8_t* payload, uint32_t nof_bytes) = 0;
-
-    // helper functions
-    virtual void debug_state() = 0;
-    const char*  get_rb_name();
-  };
-
-  // Transmitter sub-class for LTE
-  class rlc_um_tx : public rlc_um_tx_base
-  {
-  public:
-    rlc_um_tx(srslte::log* log_);
-
-    bool configure(rlc_config_t cfg, std::string rb_name);
-    int  build_data_pdu(unique_byte_buffer_t pdu, uint8_t* payload, uint32_t nof_bytes);
-
-  private:
-    /****************************************************************************
-     * State variables and counters
-     * Ref: 3GPP TS 36.322 v10.0.0 Section 7
-     ***************************************************************************/
-    uint32_t vt_us = 0; // Send state. SN to be assigned for next PDU.
-
-    void debug_state();
-  };
-
-  // Transmitter sub-class for NR
-  class rlc_um_tx_nr : public rlc_um_tx_base
-  {
-  public:
-    rlc_um_tx_nr(srslte::log* log_);
-
-    bool configure(rlc_config_t cfg, std::string rb_name);
-    int  build_data_pdu(unique_byte_buffer_t pdu, uint8_t* payload, uint32_t nof_bytes);
-
-  private:
-    uint32_t TX_Next = 0; // send state as defined in TS 38.322 v15.3 Section 7
-
-    void debug_state();
-  };
-
-  // Receiver sub-class
-  class rlc_um_rx : public timer_callback {
-  public:
-    rlc_um_rx(srslte::log*               log_,
-              uint32_t                   lcid_,
-              srsue::pdcp_interface_rlc* pdcp_,
-              srsue::rrc_interface_rlc*  rrc_,
-              srslte::timer_handler*     timers_);
-    ~rlc_um_rx();
-    void     stop();
-    void     reestablish();
-    bool     configure(rlc_config_t cfg, std::string rb_name);
-    void handle_data_pdu(uint8_t *payload, uint32_t nof_bytes);
-    void reassemble_rx_sdus();
-    bool pdu_belongs_to_rx_sdu();
-    bool inside_reordering_window(uint16_t sn);
-    uint32_t get_num_rx_bytes();
-    void reset_metrics();
-
-    // Timeout callback interface
-    void timer_expired(uint32_t timeout_id);
-
-  private:
-    void reset();
-
-    byte_buffer_pool*      pool   = nullptr;
-    srslte::log*           log    = nullptr;
-    srslte::timer_handler* timers = nullptr;
-    std::string            rb_name;
-
-    /****************************************************************************
-     * Configurable parameters
-     * Ref: 3GPP TS 36.322 v10.0.0 Section 7
-     ***************************************************************************/
-    rlc_config_t cfg = {};
-
-    // Rx window
-    std::map<uint32_t, rlc_umd_pdu_t>   rx_window;
-
-    // RX SDU buffers
-    unique_byte_buffer_t                rx_sdu;
-    uint32_t                            vr_ur_in_rx_sdu = 0;
-
-    // Rx state variables and counter
-    uint32_t vr_ur    = 0; // Receive state. SN of earliest PDU still considered for reordering.
-    uint32_t vr_ux    = 0; // t_reordering state. SN following PDU which triggered t_reordering.
-    uint32_t vr_uh    = 0; // Highest rx state. SN following PDU with highest SN among rxed PDUs.
-    bool     pdu_lost = false;
-
-    uint32_t num_rx_bytes = 0;
-
-    // Upper layer handles and variables
-    srsue::pdcp_interface_rlc* pdcp = nullptr;
-    srsue::rrc_interface_rlc*  rrc  = nullptr;
-    uint32_t                   lcid = 0;
-
-    // Mutexes
-    std::mutex mutex;
-
-    bool rx_enabled = false;
-
-    /****************************************************************************
-     * Timers
-     * Ref: 3GPP TS 36.322 v10.0.0 Section 7
-     ***************************************************************************/
-    srslte::timer_handler::unique_timer reordering_timer;
-
-    // helper functions
-    void        debug_state();
-    const char* get_rb_name();
-  };
-
-  // Common variables needed by parent class
-  srsue::rrc_interface_rlc* rrc               = nullptr;
-  srslte::log*              log               = nullptr;
-  uint32_t                  lcid              = 0;
-  rlc_config_t              cfg               = {};
-  std::string               rb_name;
-  byte_buffer_pool*         pool = nullptr;
-
-  std::string               get_rb_name(srsue::rrc_interface_rlc *rrc, uint32_t lcid, bool is_mrb);
-
-  // Rx and Tx objects
-  std::unique_ptr<rlc_um_tx_base> tx;
-  rlc_um_rx rx;
-};
-
-/****************************************************************************
- * Header pack/unpack helper functions
- * Ref: 3GPP TS 36.322 v10.0.0 Section 6.2.1
- ***************************************************************************/
-void rlc_um_read_data_pdu_header(byte_buffer_t* pdu, rlc_umd_sn_size_t sn_size, rlc_umd_pdu_header_t* header);
-void        rlc_um_read_data_pdu_header(uint8_t *payload, uint32_t nof_bytes, rlc_umd_sn_size_t sn_size, rlc_umd_pdu_header_t *header);
-void rlc_um_write_data_pdu_header(rlc_umd_pdu_header_t* header, byte_buffer_t* pdu);
-
-uint32_t    rlc_um_packed_length(rlc_umd_pdu_header_t *header);
-bool        rlc_um_start_aligned(uint8_t fi);
-bool        rlc_um_end_aligned(uint8_t fi);
-
-/****************************************************************************
- * Header pack/unpack helper functions for NR
- * Ref: 3GPP TS 38.322 v15.3.0 Section 6.2.2.3
- ***************************************************************************/
-uint32_t rlc_um_nr_read_data_pdu_header(const byte_buffer_t*      pdu,
-                                        const rlc_um_nr_sn_size_t sn_size,
-                                        rlc_um_nr_pdu_header_t*   header);
-
-uint32_t rlc_um_nr_read_data_pdu_header(const uint8_t*            payload,
-                                        const uint32_t            nof_bytes,
-                                        const rlc_um_nr_sn_size_t sn_size,
-                                        rlc_um_nr_pdu_header_t*   header);
-
-uint32_t rlc_um_nr_write_data_pdu_header(const rlc_um_nr_pdu_header_t& header, byte_buffer_t* pdu);
-
-uint32_t rlc_um_nr_packed_length(const rlc_um_nr_pdu_header_t& header);
-
-} // namespace srslte
-
-#endif // SRSLTE_RLC_UM_H

lib/include/srslte/upper/rlc_um_base.h

@@ -0,0 +1,165 @@
+/*
+ * Copyright 2013-2019 Software Radio Systems Limited
+ *
+ * This file is part of srsLTE.
+ *
+ * srsLTE is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * srsLTE is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * A copy of the GNU Affero General Public License can be found in
+ * the LICENSE file in the top-level directory of this distribution
+ * and at http://www.gnu.org/licenses/.
+ *
+ */
+
+#ifndef SRSLTE_RLC_UM_BASE_H
+#define SRSLTE_RLC_UM_BASE_H
+
+#include "srslte/common/buffer_pool.h"
+#include "srslte/common/common.h"
+#include "srslte/common/log.h"
+#include "srslte/interfaces/ue_interfaces.h"
+#include "srslte/upper/rlc_common.h"
+#include "srslte/upper/rlc_tx_queue.h"
+#include <map>
+#include <mutex>
+#include <pthread.h>
+#include <queue>
+
+namespace srslte {
+
+class rlc_um_base : public rlc_common
+{
+public:
+  rlc_um_base(srslte::log*               log_,
+              uint32_t                   lcid_,
+              srsue::pdcp_interface_rlc* pdcp_,
+              srsue::rrc_interface_rlc*  rrc_,
+              srslte::timer_handler*            timers_);
+  virtual ~rlc_um_base();
+  void reestablish();
+  void stop();
+  void empty_queue();
+  bool is_mrb();
+
+  rlc_mode_t get_mode();
+  uint32_t   get_bearer();
+
+  // PDCP interface
+  void write_sdu(unique_byte_buffer_t sdu, bool blocking = true);
+
+  // MAC interface
+  bool     has_data();
+  uint32_t get_buffer_state();
+  int      read_pdu(uint8_t* payload, uint32_t nof_bytes);
+  void     write_pdu(uint8_t* payload, uint32_t nof_bytes);
+  int      get_increment_sequence_num();
+
+  rlc_bearer_metrics_t get_metrics();
+  void     reset_metrics();
+
+protected:
+  // Transmitter sub-class base
+  class rlc_um_base_tx
+  {
+  public:
+    rlc_um_base_tx(rlc_um_base* parent_);
+    virtual ~rlc_um_base_tx();
+    virtual bool     configure(rlc_config_t cfg, std::string rb_name) = 0;
+    int              build_data_pdu(uint8_t* payload, uint32_t nof_bytes);
+    void             stop();
+    void             reestablish();
+    void             empty_queue();
+    void             write_sdu(unique_byte_buffer_t sdu);
+    void             try_write_sdu(unique_byte_buffer_t sdu);
+    void             reset_metrics();
+    bool             has_data();
+    virtual uint32_t get_buffer_state() = 0;
+
+  protected:
+    byte_buffer_pool* pool = nullptr;
+    srslte::log*      log  = nullptr;
+    std::string       rb_name;
+
+    rlc_config_t cfg = {};
+
+    // TX SDU buffers
+    rlc_tx_queue         tx_sdu_queue;
+    unique_byte_buffer_t tx_sdu;
+
+    // Mutexes
+    std::mutex mutex;
+
+    virtual int build_data_pdu(unique_byte_buffer_t pdu, uint8_t* payload, uint32_t nof_bytes) = 0;
+
+    // helper functions
+    virtual void debug_state() = 0;
+  };
+
+  // Receiver sub-class base
+  class rlc_um_base_rx : public timer_callback
+  {
+
+  public:
+    rlc_um_base_rx(rlc_um_base* parent_);
+    virtual ~rlc_um_base_rx();
+    virtual bool configure() = 0;
+
+    virtual void stop()        = 0;
+    virtual void reestablish() = 0;
+
+    virtual void handle_data_pdu(uint8_t* payload, uint32_t nof_bytes) = 0;
+
+  protected:
+    byte_buffer_pool*          pool   = nullptr;
+    srslte::log*               log    = nullptr;
+    srslte::timer_handler*            timers = nullptr;
+    srsue::pdcp_interface_rlc* pdcp   = nullptr;
+    srsue::rrc_interface_rlc*  rrc    = nullptr;
+
+    rlc_bearer_metrics_t& metrics;
+
+    std::string  rb_name;
+    rlc_config_t cfg = {};
+
+    unique_byte_buffer_t rx_sdu;
+
+    uint32_t& lcid;
+
+    std::mutex mutex;
+
+    // helper functions
+    virtual void debug_state() = 0;
+  };
+
+  // Common variables needed by parent class
+  srsue::rrc_interface_rlc*  rrc    = nullptr;
+  srsue::pdcp_interface_rlc* pdcp   = nullptr;
+  srslte::log*               log    = nullptr;
+  srslte::timer_handler*            timers = nullptr;
+  uint32_t                   lcid   = 0;
+  rlc_config_t               cfg    = {};
+  std::string                rb_name;
+  byte_buffer_pool*          pool = nullptr;
+  std::string                get_rb_name(srsue::rrc_interface_rlc* rrc, uint32_t lcid, bool is_mrb);
+
+  // Rx and Tx objects
+  std::unique_ptr<rlc_um_base_tx> tx;
+  std::unique_ptr<rlc_um_base_rx> rx;
+
+  bool     tx_enabled   = false;
+  bool     rx_enabled   = false;
+
+  rlc_bearer_metrics_t metrics = {};
+};
+
+} // namespace srslte
+
+#endif // SRSLTE_RLC_UM_BASE_H

lib/include/srslte/upper/rlc_um_lte.h

@@ -0,0 +1,135 @@
+/*
+ * Copyright 2013-2019 Software Radio Systems Limited
+ *
+ * This file is part of srsLTE.
+ *
+ * srsLTE is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * srsLTE is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * A copy of the GNU Affero General Public License can be found in
+ * the LICENSE file in the top-level directory of this distribution
+ * and at http://www.gnu.org/licenses/.
+ *
+ */
+
+#ifndef SRSLTE_RLC_UM_LTE_H
+#define SRSLTE_RLC_UM_LTE_H
+
+#include "srslte/common/buffer_pool.h"
+#include "srslte/common/common.h"
+#include "srslte/common/log.h"
+#include "srslte/interfaces/ue_interfaces.h"
+#include "srslte/upper/rlc_tx_queue.h"
+#include "srslte/upper/rlc_um_base.h"
+#include <map>
+#include <mutex>
+#include <pthread.h>
+#include <queue>
+
+namespace srslte {
+
+typedef struct {
+  rlc_umd_pdu_header_t header;
+  unique_byte_buffer_t buf;
+} rlc_umd_pdu_t;
+
+class rlc_um_lte : public rlc_um_base
+{
+public:
+  rlc_um_lte(srslte::log*               log_,
+             uint32_t                   lcid_,
+             srsue::pdcp_interface_rlc* pdcp_,
+             srsue::rrc_interface_rlc*  rrc_,
+             srslte::timer_handler*            timers_);
+  ~rlc_um_lte();
+  bool configure(rlc_config_t cnfg);
+
+private:
+  // Transmitter sub-class for LTE
+  class rlc_um_lte_tx : public rlc_um_base_tx
+  {
+  public:
+    rlc_um_lte_tx(rlc_um_base* parent_);
+
+    bool     configure(rlc_config_t cfg, std::string rb_name);
+    int      build_data_pdu(unique_byte_buffer_t pdu, uint8_t* payload, uint32_t nof_bytes);
+    uint32_t get_buffer_state();
+
+  private:
+    /****************************************************************************
+     * State variables and counters
+     * Ref: 3GPP TS 36.322 v10.0.0 Section 7
+     ***************************************************************************/
+    uint32_t vt_us = 0; // Send state. SN to be assigned for next PDU.
+
+    void debug_state();
+  };
+
+  // Receiver sub-class for LTE
+  class rlc_um_lte_rx : public rlc_um_base_rx
+  {
+  public:
+    rlc_um_lte_rx(rlc_um_base* parent_);
+    ~rlc_um_lte_rx();
+    void stop();
+    void reestablish();
+    bool configure();
+    void handle_data_pdu(uint8_t* payload, uint32_t nof_bytes);
+    void reassemble_rx_sdus();
+    bool pdu_belongs_to_rx_sdu();
+    bool inside_reordering_window(uint16_t sn);
+
+    // Timeout callback interface
+    void timer_expired(uint32_t timeout_id);
+
+  private:
+    void reset();
+
+    // Rx window
+    std::map<uint32_t, rlc_umd_pdu_t> rx_window;
+
+    // RX SDU buffers
+    uint32_t vr_ur_in_rx_sdu = 0;
+
+    // Rx state variables and counter
+    uint32_t vr_ur    = 0; // Receive state. SN of earliest PDU still considered for reordering.
+    uint32_t vr_ux    = 0; // t_reordering state. SN following PDU which triggered t_reordering.
+    uint32_t vr_uh    = 0; // Highest rx state. SN following PDU with highest SN among rxed PDUs.
+    bool     pdu_lost = false;
+
+    /****************************************************************************
+     * Timers
+     * Ref: 3GPP TS 36.322 v10.0.0 Section 7
+     ***************************************************************************/
+    srslte::timer_handler::unique_timer reordering_timer;
+
+    // helper functions
+    void debug_state();
+  };
+};
+
+/****************************************************************************
+ * Header pack/unpack helper functions
+ * Ref: 3GPP TS 36.322 v10.0.0 Section 6.2.1
+ ***************************************************************************/
+void rlc_um_read_data_pdu_header(byte_buffer_t* pdu, rlc_umd_sn_size_t sn_size, rlc_umd_pdu_header_t* header);
+void rlc_um_read_data_pdu_header(uint8_t*              payload,
+                                 uint32_t              nof_bytes,
+                                 rlc_umd_sn_size_t     sn_size,
+                                 rlc_umd_pdu_header_t* header);
+void rlc_um_write_data_pdu_header(rlc_umd_pdu_header_t* header, byte_buffer_t* pdu);
+
+uint32_t rlc_um_packed_length(rlc_umd_pdu_header_t* header);
+bool     rlc_um_start_aligned(uint8_t fi);
+bool     rlc_um_end_aligned(uint8_t fi);
+
+} // namespace srslte
+
+#endif // SRSLTE_RLC_UM_LTE_H

lib/include/srslte/upper/rlc_um_nr.h

@@ -0,0 +1,143 @@
+/*
+ * Copyright 2013-2019 Software Radio Systems Limited
+ *
+ * This file is part of srsLTE.
+ *
+ * srsLTE is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * srsLTE is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * A copy of the GNU Affero General Public License can be found in
+ * the LICENSE file in the top-level directory of this distribution
+ * and at http://www.gnu.org/licenses/.
+ *
+ */
+
+#ifndef SRSLTE_RLC_UM_NR_H
+#define SRSLTE_RLC_UM_NR_H
+
+#include "srslte/common/buffer_pool.h"
+#include "srslte/common/common.h"
+#include "srslte/common/log.h"
+#include "srslte/interfaces/ue_interfaces.h"
+#include "srslte/upper/rlc_tx_queue.h"
+#include "srslte/upper/rlc_um_base.h"
+#include <map>
+#include <mutex>
+#include <pthread.h>
+#include <queue>
+
+namespace srslte {
+
+typedef struct {
+  rlc_um_nr_pdu_header_t header;
+  unique_byte_buffer_t   buf;
+} rlc_umd_pdu_nr_t;
+
+class rlc_um_nr : public rlc_um_base
+{
+public:
+  rlc_um_nr(srslte::log*               log_,
+            uint32_t                   lcid_,
+            srsue::pdcp_interface_rlc* pdcp_,
+            srsue::rrc_interface_rlc*  rrc_,
+            srslte::timer_handler*            timers_);
+  ~rlc_um_nr();
+  bool configure(rlc_config_t cnfg);
+
+private:
+  // Transmitter sub-class for NR
+  class rlc_um_nr_tx : public rlc_um_base_tx
+  {
+  public:
+    rlc_um_nr_tx(rlc_um_base* parent_);
+
+    bool     configure(rlc_config_t cfg, std::string rb_name);
+    int      build_data_pdu(unique_byte_buffer_t pdu, uint8_t* payload, uint32_t nof_bytes);
+    uint32_t get_buffer_state();
+
+  private:
+    uint32_t TX_Next = 0; // send state as defined in TS 38.322 v15.3 Section 7
+                          // It holds the value of the SN to be assigned for the next newly generated UMD PDU with
+                          // segment. It is initially set to 0, and is updated after the UM RLC entity submits a UMD PDU
+                          // including the last segment of an RLC SDU to lower layers.
+
+    uint32_t next_so = 0; // The segment offset for the next generated PDU
+
+    void debug_state();
+  };
+
+  // Receiver sub-class for NR
+  class rlc_um_nr_rx : public rlc_um_base_rx
+  {
+  public:
+    rlc_um_nr_rx(rlc_um_base* parent_);
+
+    bool configure();
+    void handle_data_pdu(uint8_t* payload, uint32_t nof_bytes);
+
+    void reestablish();
+    void stop();
+
+    void timer_expired(uint32_t timeout_id);
+
+  private:
+    bool sn_in_reassembly_window(const uint32_t sn);
+    bool sn_invalid_for_rx_buffer(const uint32_t sn);
+    bool has_missing_byte_segment(const uint32_t sn);
+    unique_byte_buffer_t
+    rlc_um_nr_strip_pdu_header(const rlc_um_nr_pdu_header_t& header, const uint8_t* payload, const uint32_t nof_bytes);
+
+    void handle_rx_buffer_update(const uint32_t sn);
+
+    uint32_t RX_Next_Reassembly = 0; // the earliest SN that is still considered for reassembly
+    uint32_t RX_Timer_Trigger   = 0; // the SN following the SN which triggered t-Reassembly
+    uint32_t RX_Next_Highest    = 0; // the SN following the SN of the UMD PDU with the highest SN among
+                                     // received UMD PDUs. It serves as the higher edge of the reassembly window.
+
+    // Rx window
+    typedef struct {
+      std::map<uint32_t, rlc_umd_pdu_nr_t> segments; // Map of segments with SO as key
+      unique_byte_buffer_t                 sdu;
+      uint32_t                             next_expected_so;
+      uint32_t                             total_sdu_length;
+    } rlc_umd_pdu_segments_nr_t;
+    std::map<uint32_t, rlc_umd_pdu_segments_nr_t> rx_window;
+
+    void update_total_sdu_length(rlc_umd_pdu_segments_nr_t& pdu_segments, const rlc_umd_pdu_nr_t& rx_pdu);
+
+    // TS 38.322 Sec. 7.3
+    srslte::timer_handler::unique_timer reassembly_timer; // to detect loss of RLC PDUs at lower layers
+
+    // helper functions
+    void reset();
+    void debug_state();
+  };
+};
+
+/****************************************************************************
+ * Header pack/unpack helper functions for NR
+ * Ref: 3GPP TS 38.322 v15.3.0 Section 6.2.2.3
+ ***************************************************************************/
+uint32_t rlc_um_nr_read_data_pdu_header(const byte_buffer_t*      pdu,
+                                        const rlc_um_nr_sn_size_t sn_size,
+                                        rlc_um_nr_pdu_header_t*   header);
+
+uint32_t rlc_um_nr_read_data_pdu_header(const uint8_t*            payload,
+                                        const uint32_t            nof_bytes,
+                                        const rlc_um_nr_sn_size_t sn_size,
+                                        rlc_um_nr_pdu_header_t*   header);
+
+uint32_t rlc_um_nr_write_data_pdu_header(const rlc_um_nr_pdu_header_t& header, byte_buffer_t* pdu);
+
+uint32_t rlc_um_nr_packed_length(const rlc_um_nr_pdu_header_t& header);
+
+} // namespace srslte
+
+#endif // SRSLTE_RLC_UM_NR_H

lib/src/upper/CMakeLists.txt

@@ -18,7 +18,17 @@
 # and at http://www.gnu.org/licenses/.
 #
 
-set(SOURCES gtpu.cc pdcp.cc pdcp_entity_base.cc pdcp_entity_lte.cc pdcp_entity_nr.cc rlc.cc rlc_am_lte.cc rlc_um.cc rlc_tm.cc)
+set(SOURCES gtpu.cc
+            pdcp.cc
+            pdcp_entity_base.cc
+            pdcp_entity_lte.cc
+            pdcp_entity_nr.cc
+            rlc.cc
+            rlc_tm.cc
+            rlc_um_base.cc
+            rlc_um_lte.cc
+            rlc_um_nr.cc
+            rlc_am_lte.cc)
 add_library(srslte_upper STATIC ${SOURCES})
 target_link_libraries(srslte_upper srslte_common srslte_asn1)
 install(TARGETS srslte_upper DESTINATION ${LIBRARY_DIR})

lib/src/upper/rlc.cc

@@ -22,7 +22,8 @@
 #include "srslte/upper/rlc.h"
 #include "srslte/upper/rlc_am_lte.h"
 #include "srslte/upper/rlc_tm.h"
-#include "srslte/upper/rlc_um.h"
+#include "srslte/upper/rlc_um_lte.h"
+#include "srslte/upper/rlc_um_nr.h"
 
 namespace srslte {
 
@@ -100,20 +101,21 @@ void rlc::get_metrics(rlc_metrics_t &m)
   double secs = (double)metrics_time[0].tv_sec + metrics_time[0].tv_usec*1e-6;
 
   for (rlc_map_t::iterator it = rlc_array.begin(); it != rlc_array.end(); ++it) {
-    m.dl_tput_mbps[it->first] = (it->second->get_num_rx_bytes()*8/static_cast<double>(1e6))/secs;
+    rlc_bearer_metrics_t metrics = it->second->get_metrics();
-    m.ul_tput_mbps[it->first] = (it->second->get_num_tx_bytes()*8/static_cast<double>(1e6))/secs;
     rlc_log->info("LCID=%d, RX throughput: %4.6f Mbps. TX throughput: %4.6f Mbps.\n",
                   it->first,
-                    (it->second->get_num_rx_bytes()*8/static_cast<double>(1e6))/secs,
+                  (metrics.num_rx_bytes * 8 / static_cast<double>(1e6)) / secs,
-                    (it->second->get_num_tx_bytes()*8/static_cast<double>(1e6))/secs);
+                  (metrics.num_tx_bytes * 8 / static_cast<double>(1e6)) / secs);
+    m.bearer[it->first] = metrics;
   }
 
   // Add multicast metrics
   for (rlc_map_t::iterator it = rlc_array_mrb.begin(); it != rlc_array_mrb.end(); ++it) {
-    m.dl_tput_mbps[it->first] = (it->second->get_num_rx_bytes()*8/static_cast<double>(1e6))/secs;
+    rlc_bearer_metrics_t metrics = it->second->get_metrics();
     rlc_log->info("MCH_LCID=%d, RX throughput: %4.6f Mbps\n",
                   it->first,
-                  (it->second->get_num_rx_bytes()*8/static_cast<double>(1e6))/secs);
+                  (metrics.num_rx_bytes * 8 / static_cast<double>(1e6)) / secs);
+    m.bearer[it->first] = metrics;
   }
 
   memcpy(&metrics_time[1], &metrics_time[2], sizeof(struct timeval));
@@ -382,6 +384,7 @@ void rlc::add_bearer(uint32_t lcid, rlc_config_t cnfg)
   rlc_common *rlc_entity = NULL;
 
   if (not valid_lcid(lcid)) {
+    if (cnfg.rat == srslte_rat_t::lte) {
       switch (cnfg.rlc_mode) {
         case rlc_mode_t::tm:
           rlc_entity = new rlc_tm(rlc_log, lcid, pdcp, rrc, timers);
@@ -390,12 +393,25 @@ void rlc::add_bearer(uint32_t lcid, rlc_config_t cnfg)
           rlc_entity = new rlc_am_lte(rlc_log, lcid, pdcp, rrc, timers);
           break;
         case rlc_mode_t::um:
-        rlc_entity = new rlc_um(rlc_log, lcid, pdcp, rrc, timers);
+          rlc_entity = new rlc_um_lte(rlc_log, lcid, pdcp, rrc, timers);
           break;
         default:
           rlc_log->error("Cannot add RLC entity - invalid mode\n");
           goto unlock_and_exit;
       }
+    } else if (cnfg.rat == srslte_rat_t::nr) {
+      switch (cnfg.rlc_mode) {
+        case rlc_mode_t::tm:
+          rlc_entity = new rlc_tm(rlc_log, lcid, pdcp, rrc, timers);
+          break;
+        case rlc_mode_t::um:
+          rlc_entity = new rlc_um_nr(rlc_log, lcid, pdcp, rrc, timers);
+          break;
+        default:
+          rlc_log->error("Cannot add RLC entity - invalid mode\n");
+          goto unlock_and_exit;
+      }
+    }
 
     if (not rlc_array.insert(rlc_map_pair_t(lcid, rlc_entity)).second) {
       rlc_log->error("Error inserting RLC entity in to array\n.");
@@ -406,7 +422,7 @@ void rlc::add_bearer(uint32_t lcid, rlc_config_t cnfg)
   }
 
   // configure and add to array
-  if (cnfg.rlc_mode != rlc_mode_t::tm) {
+  if (cnfg.rlc_mode != rlc_mode_t::tm and rlc_array.find(lcid) != rlc_array.end()) {
     if (not rlc_array.at(lcid)->configure(cnfg)) {
       rlc_log->error("Error configuring RLC entity\n.");
       goto delete_and_exit;
@@ -431,7 +447,7 @@ void rlc::add_bearer_mrb(uint32_t lcid)
   rlc_common* rlc_entity = NULL;
 
   if (not valid_lcid_mrb(lcid)) {
-    rlc_entity = new rlc_um(rlc_log, lcid, pdcp, rrc, timers);
+    rlc_entity = new rlc_um_lte(rlc_log, lcid, pdcp, rrc, timers);
     // configure and add to array
     if (not rlc_entity->configure(rlc_config_t::mch_config())) {
       rlc_log->error("Error configuring RLC entity\n.");

lib/src/upper/rlc_am_lte.cc

@@ -102,14 +102,9 @@ uint32_t rlc_am_lte::get_bearer()
   return lcid;
 }
 
-uint32_t rlc_am_lte::get_num_rx_bytes()
+rlc_bearer_metrics_t rlc_am_lte::get_metrics()
 {
-  return rx.get_num_rx_bytes();
+  return metrics;
-}
-
-uint32_t rlc_am_lte::get_num_tx_bytes()
-{
-  return tx.get_num_tx_bytes();
 }
 
 void rlc_am_lte::reset_metrics()

lib/src/upper/rlc_tm.cc

@@ -126,20 +126,14 @@ uint32_t rlc_tm::get_buffer_state()
   return ul_queue.size_bytes();
 }
 
-uint32_t rlc_tm::get_num_tx_bytes()
+rlc_bearer_metrics_t rlc_tm::get_metrics()
 {
-  return num_tx_bytes;
+  return metrics;
-}
-
-uint32_t rlc_tm::get_num_rx_bytes()
-{
-  return num_rx_bytes;
 }
 
 void rlc_tm::reset_metrics()
 {
-  num_tx_bytes = 0;
+  metrics = {};
-  num_rx_bytes = 0;
 }
 
 int rlc_tm::read_pdu(uint8_t *payload, uint32_t nof_bytes)
@@ -163,7 +157,7 @@ int rlc_tm::read_pdu(uint8_t *payload, uint32_t nof_bytes)
                   ul_queue.size(),
                   ul_queue.size_bytes());
 
-    num_tx_bytes += pdu_size;
+    metrics.num_tx_bytes += pdu_size;
     return pdu_size;
   } else {
     log->warning("Queue empty while trying to read\n");
@@ -182,7 +176,7 @@ void rlc_tm::write_pdu(uint8_t *payload, uint32_t nof_bytes)
     memcpy(buf->msg, payload, nof_bytes);
     buf->N_bytes = nof_bytes;
     buf->set_timestamp();
-    num_rx_bytes += nof_bytes;
+    metrics.num_rx_bytes += nof_bytes;
     if (rrc->get_rb_name(lcid) == "SRB0") {
       rrc->write_pdu(lcid, std::move(buf));
     } else {

lib/src/upper/rlc_um_base.cc

@@ -0,0 +1,285 @@
+/*
+ * Copyright 2013-2019 Software Radio Systems Limited
+ *
+ * This file is part of srsLTE.
+ *
+ * srsLTE is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * srsLTE is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * A copy of the GNU Affero General Public License can be found in
+ * the LICENSE file in the top-level directory of this distribution
+ * and at http://www.gnu.org/licenses/.
+ *
+ */
+
+#include "srslte/upper/rlc_um_base.h"
+#include <sstream>
+
+using namespace asn1::rrc;
+
+namespace srslte {
+
+rlc_um_base::rlc_um_base(srslte::log*               log_,
+                         uint32_t                   lcid_,
+                         srsue::pdcp_interface_rlc* pdcp_,
+                         srsue::rrc_interface_rlc*  rrc_,
+                         srslte::timer_handler*     timers_) :
+  log(log_), lcid(lcid_), pdcp(pdcp_), rrc(rrc_), timers(timers_), pool(byte_buffer_pool::get_instance())
+{
+}
+
+rlc_um_base::~rlc_um_base() {}
+
+void rlc_um_base::stop()
+{
+  if (tx) {
+    tx->stop();
+  }
+
+  if (rx) {
+    rx->stop();
+  }
+}
+
+rlc_mode_t rlc_um_base::get_mode()
+{
+  return rlc_mode_t::um;
+}
+
+uint32_t rlc_um_base::get_bearer()
+{
+  return lcid;
+}
+
+bool rlc_um_base::is_mrb()
+{
+  return cfg.um.is_mrb;
+}
+
+void rlc_um_base::reestablish()
+{
+  tx_enabled = false;
+
+  if (tx) {
+    tx->reestablish(); // calls stop and enables tx again
+  }
+
+  if (rx) {
+    rx->reestablish(); // nothing else needed
+  }
+
+  tx_enabled = true;
+}
+
+void rlc_um_base::empty_queue()
+{
+  // Drop all messages in TX SDU queue
+  if (tx) {
+    tx->empty_queue();
+  }
+}
+
+/****************************************************************************
+ * PDCP interface
+ ***************************************************************************/
+void rlc_um_base::write_sdu(unique_byte_buffer_t sdu, bool blocking)
+{
+  if (not tx_enabled || not tx) {
+    log->debug("%s is currently deactivated. Dropping SDU (%d B)\n", rb_name.c_str(), sdu->N_bytes);
+    metrics.num_dropped_sdus++;
+    return;
+  }
+
+  if (blocking) {
+    tx->write_sdu(std::move(sdu));
+  } else {
+    tx->try_write_sdu(std::move(sdu));
+  }
+}
+
+/****************************************************************************
+ * MAC interface
+ ***************************************************************************/
+
+bool rlc_um_base::has_data()
+{
+  if (tx) {
+    return tx->has_data();
+  }
+  return false;
+}
+
+uint32_t rlc_um_base::get_buffer_state()
+{
+  if (tx) {
+    return tx->get_buffer_state();
+  }
+  return 0;
+}
+
+int rlc_um_base::read_pdu(uint8_t* payload, uint32_t nof_bytes)
+{
+  if (tx && tx_enabled) {
+    uint32_t len = tx->build_data_pdu(payload, nof_bytes);
+    metrics.num_tx_bytes += len;
+    metrics.num_tx_pdus++;
+    return len;
+  }
+  return 0;
+}
+
+void rlc_um_base::write_pdu(uint8_t* payload, uint32_t nof_bytes)
+{
+  if (rx && rx_enabled) {
+    metrics.num_rx_pdus++;
+    metrics.num_rx_bytes += nof_bytes;
+    rx->handle_data_pdu(payload, nof_bytes);
+  }
+}
+
+rlc_bearer_metrics_t rlc_um_base::get_metrics()
+{
+  return metrics;
+}
+
+void rlc_um_base::reset_metrics()
+{
+  metrics = {};
+}
+
+/****************************************************************************
+ * Helper functions
+ ***************************************************************************/
+
+std::string rlc_um_base::get_rb_name(srsue::rrc_interface_rlc* rrc, uint32_t lcid, bool is_mrb)
+{
+  if (is_mrb) {
+    std::stringstream ss;
+    ss << "MRB" << lcid;
+    return ss.str();
+  } else {
+    return rrc->get_rb_name(lcid);
+  }
+}
+
+/****************************************************************************
+ * Rx subclass implementation (base)
+ ***************************************************************************/
+
+rlc_um_base::rlc_um_base_rx::rlc_um_base_rx(rlc_um_base* parent_) :
+  pool(parent_->pool),
+  log(parent_->log),
+  timers(parent_->timers),
+  pdcp(parent_->pdcp),
+  rrc(parent_->rrc),
+  cfg(parent_->cfg),
+  metrics(parent_->metrics),
+  lcid(parent_->lcid)
+{
+}
+
+rlc_um_base::rlc_um_base_rx::~rlc_um_base_rx() {}
+
+/****************************************************************************
+ * Tx subclass implementation (base)
+ ***************************************************************************/
+
+rlc_um_base::rlc_um_base_tx::rlc_um_base_tx(rlc_um_base* parent_) : log(parent_->log), pool(parent_->pool) {}
+
+rlc_um_base::rlc_um_base_tx::~rlc_um_base_tx() {}
+
+void rlc_um_base::rlc_um_base_tx::stop()
+{
+  empty_queue();
+}
+
+void rlc_um_base::rlc_um_base_tx::reestablish()
+{
+  stop();
+  // bearer is enabled in base class
+}
+
+void rlc_um_base::rlc_um_base_tx::empty_queue()
+{
+  std::lock_guard<std::mutex> lock(mutex);
+
+  // deallocate all SDUs in transmit queue
+  while (not tx_sdu_queue.is_empty()) {
+    unique_byte_buffer_t buf = tx_sdu_queue.read();
+  }
+
+  // deallocate SDU that is currently processed
+  tx_sdu.reset();
+}
+
+bool rlc_um_base::rlc_um_base_tx::has_data()
+{
+  return (tx_sdu != nullptr || !tx_sdu_queue.is_empty());
+}
+
+void rlc_um_base::rlc_um_base_tx::write_sdu(unique_byte_buffer_t sdu)
+{
+  if (sdu) {
+    log->info_hex(sdu->msg,
+                  sdu->N_bytes,
+                  "%s Tx SDU (%d B, tx_sdu_queue_len=%d)",
+                  rb_name.c_str(),
+                  sdu->N_bytes,
+                  tx_sdu_queue.size());
+    tx_sdu_queue.write(std::move(sdu));
+  } else {
+    log->warning("NULL SDU pointer in write_sdu()\n");
+  }
+}
+
+void rlc_um_base::rlc_um_base_tx::try_write_sdu(unique_byte_buffer_t sdu)
+{
+  if (sdu) {
+    uint8_t*                              msg_ptr   = sdu->msg;
+    uint32_t                              nof_bytes = sdu->N_bytes;
+    std::pair<bool, unique_byte_buffer_t> ret       = tx_sdu_queue.try_write(std::move(sdu));
+    if (ret.first) {
+      log->info_hex(
+          msg_ptr, nof_bytes, "%s Tx SDU (%d B, tx_sdu_queue_len=%d)", rb_name.c_str(), nof_bytes, tx_sdu_queue.size());
+    } else {
+      log->info_hex(ret.second->msg,
+                    ret.second->N_bytes,
+                    "[Dropped SDU] %s Tx SDU (%d B, tx_sdu_queue_len=%d)",
+                    rb_name.c_str(),
+                    ret.second->N_bytes,
+                    tx_sdu_queue.size());
+    }
+  } else {
+    log->warning("NULL SDU pointer in write_sdu()\n");
+  }
+}
+
+int rlc_um_base::rlc_um_base_tx::build_data_pdu(uint8_t* payload, uint32_t nof_bytes)
+{
+  unique_byte_buffer_t pdu;
+  {
+    std::lock_guard<std::mutex> lock(mutex);
+    log->debug("MAC opportunity - %d bytes\n", nof_bytes);
+
+    if (!tx_sdu && tx_sdu_queue.size() == 0) {
+      log->info("No data available to be sent\n");
+      return 0;
+    }
+
+    pdu = allocate_unique_buffer(*pool);
+    if (!pdu || pdu->N_bytes != 0) {
+      log->error("Failed to allocate PDU buffer\n");
+      return 0;
+    }
+  }
+  return build_data_pdu(std::move(pdu), payload, nof_bytes);
+}
+
+} // namespace srslte

lib/src/upper/rlc_um_lte.cc

@@ -0,0 +1,815 @@
+/*
+ * Copyright 2013-2019 Software Radio Systems Limited
+ *
+ * This file is part of srsLTE.
+ *
+ * srsLTE is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * srsLTE is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * A copy of the GNU Affero General Public License can be found in
+ * the LICENSE file in the top-level directory of this distribution
+ * and at http://www.gnu.org/licenses/.
+ *
+ */
+
+#include "srslte/upper/rlc_um_lte.h"
+#include <sstream>
+
+#define RX_MOD_BASE(x) (((x)-vr_uh - cfg.um.rx_window_size) % cfg.um.rx_mod)
+
+using namespace asn1::rrc;
+
+namespace srslte {
+
+rlc_um_lte::rlc_um_lte(srslte::log*               log_,
+                       uint32_t                   lcid_,
+                       srsue::pdcp_interface_rlc* pdcp_,
+                       srsue::rrc_interface_rlc*  rrc_,
+                       srslte::timer_handler*            timers_) :
+  rlc_um_base(log_, lcid_, pdcp_, rrc_, timers_)
+{
+}
+
+// Warning: must call stop() to properly deallocate all buffers
+rlc_um_lte::~rlc_um_lte()
+{
+  stop();
+}
+
+bool rlc_um_lte::configure(rlc_config_t cnfg_)
+{
+  // determine bearer name and configure Rx/Tx objects
+  rb_name = get_rb_name(rrc, lcid, cnfg_.um.is_mrb);
+
+  // store config
+  cfg = cnfg_;
+
+  rx.reset(new rlc_um_lte_rx(this));
+  if (not rx->configure()) {
+    return false;
+  }
+
+  tx.reset(new rlc_um_lte_tx(this));
+  if (not tx->configure(cfg, rb_name)) {
+    return false;
+  }
+
+  log->info("%s configured in %s: t_reordering=%d ms, rx_sn_field_length=%u bits, tx_sn_field_length=%u bits\n",
+            rb_name.c_str(),
+            srslte::to_string(cnfg_.rlc_mode).c_str(),
+            cfg.um.t_reordering,
+            srslte::to_number(cfg.um.rx_sn_field_length),
+            srslte::to_number(cfg.um.tx_sn_field_length));
+
+  rx_enabled = true;
+  tx_enabled = true;
+
+  return true;
+}
+
+/****************************************************************************
+ * Tx Subclass implementation for LTE
+ ***************************************************************************/
+
+rlc_um_lte::rlc_um_lte_tx::rlc_um_lte_tx(rlc_um_base* parent_) : rlc_um_base_tx(parent_) {}
+
+uint32_t rlc_um_lte::rlc_um_lte_tx::get_buffer_state()
+{
+  std::lock_guard<std::mutex> lock(mutex);
+
+  // Bytes needed for tx SDUs
+  uint32_t n_sdus  = tx_sdu_queue.size();
+  uint32_t n_bytes = tx_sdu_queue.size_bytes();
+  if (tx_sdu) {
+    n_sdus++;
+    n_bytes += tx_sdu->N_bytes;
+  }
+
+  // Room needed for header extensions? (integer rounding)
+  if (n_sdus > 1) {
+    n_bytes += ((n_sdus - 1) * 1.5) + 0.5;
+  }
+
+  // Room needed for fixed header?
+  if (n_bytes > 0)
+    n_bytes += (cfg.um.is_mrb) ? 2 : 3;
+
+  return n_bytes;
+}
+
+bool rlc_um_lte::rlc_um_lte_tx::configure(rlc_config_t cnfg_, std::string rb_name_)
+{
+  cfg = cnfg_;
+
+  if (cfg.um.tx_mod == 0) {
+    log->error("Error configuring %s RLC UM: tx_mod==0\n", rb_name.c_str());
+    return false;
+  }
+
+  tx_sdu_queue.resize(cnfg_.tx_queue_length);
+
+  rb_name    = rb_name_;
+
+  return true;
+}
+
+int rlc_um_lte::rlc_um_lte_tx::build_data_pdu(unique_byte_buffer_t pdu, uint8_t* payload, uint32_t nof_bytes)
+{
+  std::lock_guard<std::mutex> lock(mutex);
+  rlc_umd_pdu_header_t        header;
+  header.fi      = RLC_FI_FIELD_START_AND_END_ALIGNED;
+  header.sn      = vt_us;
+  header.N_li    = 0;
+  header.sn_size = cfg.um.tx_sn_field_length;
+
+  uint32_t to_move = 0;
+  uint32_t last_li = 0;
+  uint8_t* pdu_ptr = pdu->msg;
+
+  int head_len  = rlc_um_packed_length(&header);
+  int pdu_space = SRSLTE_MIN(nof_bytes, pdu->get_tailroom());
+
+  if (pdu_space <= head_len + 1) {
+    log->warning("%s Cannot build a PDU - %d bytes available, %d bytes required for header\n",
+                 rb_name.c_str(),
+                 nof_bytes,
+                 head_len);
+    return 0;
+  }
+
+  // Check for SDU segment
+  if (tx_sdu) {
+    uint32_t space = pdu_space - head_len;
+    to_move        = space >= tx_sdu->N_bytes ? tx_sdu->N_bytes : space;
+    log->debug(
+        "%s adding remainder of SDU segment - %d bytes of %d remaining\n", rb_name.c_str(), to_move, tx_sdu->N_bytes);
+    memcpy(pdu_ptr, tx_sdu->msg, to_move);
+    last_li = to_move;
+    pdu_ptr += to_move;
+    pdu->N_bytes += to_move;
+    tx_sdu->N_bytes -= to_move;
+    tx_sdu->msg += to_move;
+    if (tx_sdu->N_bytes == 0) {
+      log->debug(
+          "%s Complete SDU scheduled for tx. Stack latency: %ld us\n", rb_name.c_str(), tx_sdu->get_latency_us());
+
+      tx_sdu.reset();
+    }
+    pdu_space -= SRSLTE_MIN(to_move, pdu->get_tailroom());
+    header.fi |= RLC_FI_FIELD_NOT_START_ALIGNED; // First byte does not correspond to first byte of SDU
+  }
+
+  // Pull SDUs from queue
+  while (pdu_space > head_len + 1 && tx_sdu_queue.size() > 0) {
+    log->debug("pdu_space=%d, head_len=%d\n", pdu_space, head_len);
+    if (last_li > 0)
+      header.li[header.N_li++] = last_li;
+    head_len       = rlc_um_packed_length(&header);
+    tx_sdu         = tx_sdu_queue.read();
+    uint32_t space = pdu_space - head_len;
+    to_move        = space >= tx_sdu->N_bytes ? tx_sdu->N_bytes : space;
+    log->debug("%s adding new SDU segment - %d bytes of %d remaining\n", rb_name.c_str(), to_move, tx_sdu->N_bytes);
+    memcpy(pdu_ptr, tx_sdu->msg, to_move);
+    last_li = to_move;
+    pdu_ptr += to_move;
+    pdu->N_bytes += to_move;
+    tx_sdu->N_bytes -= to_move;
+    tx_sdu->msg += to_move;
+    if (tx_sdu->N_bytes == 0) {
+      log->debug(
+          "%s Complete SDU scheduled for tx. Stack latency: %ld us\n", rb_name.c_str(), tx_sdu->get_latency_us());
+
+      tx_sdu.reset();
+    }
+    pdu_space -= to_move;
+  }
+
+  if (tx_sdu) {
+    header.fi |= RLC_FI_FIELD_NOT_END_ALIGNED; // Last byte does not correspond to last byte of SDU
+  }
+
+  // Set SN
+  header.sn = vt_us;
+  vt_us     = (vt_us + 1) % cfg.um.tx_mod;
+
+  // Add header and TX
+  rlc_um_write_data_pdu_header(&header, pdu.get());
+  memcpy(payload, pdu->msg, pdu->N_bytes);
+  uint32_t ret = pdu->N_bytes;
+
+  log->info_hex(payload, ret, "%s Tx PDU SN=%d (%d B)\n", rb_name.c_str(), header.sn, pdu->N_bytes);
+
+  debug_state();
+
+  return ret;
+}
+
+void rlc_um_lte::rlc_um_lte_tx::debug_state()
+{
+  log->debug("%s vt_us = %d\n", rb_name.c_str(), vt_us);
+}
+
+/****************************************************************************
+ * Rx subclass implementation
+ ***************************************************************************/
+
+rlc_um_lte::rlc_um_lte_rx::rlc_um_lte_rx(rlc_um_base* parent_) : rlc_um_base_rx(parent_), reordering_timer(timers->get_unique_timer())
+{
+}
+
+rlc_um_lte::rlc_um_lte_rx::~rlc_um_lte_rx()
+{
+}
+
+bool rlc_um_lte::rlc_um_lte_rx::configure()
+{
+  if (cfg.um.rx_mod == 0) {
+    log->error("Error configuring %s RLC UM: rx_mod==0\n", rb_name.c_str());
+    return false;
+  }
+
+  // check timer
+  if (not reordering_timer.is_valid()) {
+    log->error("Configuring RLC UM RX: timers not configured\n");
+    return false;
+  }
+
+  // configure timer
+  if (cfg.um.t_reordering > 0) {
+    reordering_timer.set(static_cast<uint32_t>(cfg.um.t_reordering), [this](uint32_t tid) { timer_expired(tid); });
+  }
+
+  return true;
+}
+
+void rlc_um_lte::rlc_um_lte_rx::reestablish()
+{
+  // try to reassemble any SDUs if possible
+  if (reordering_timer.is_valid() && reordering_timer.is_running()) {
+    reordering_timer.stop();
+    timer_expired(reordering_timer.id());
+  }
+
+  std::lock_guard<std::mutex> lock(mutex);
+  reset();
+}
+
+void rlc_um_lte::rlc_um_lte_rx::stop()
+{
+  std::lock_guard<std::mutex> lock(mutex);
+  reset();
+
+  reordering_timer.stop();
+}
+
+void rlc_um_lte::rlc_um_lte_rx::reset()
+{
+  vr_ur    = 0;
+  vr_ux    = 0;
+  vr_uh    = 0;
+  pdu_lost = false;
+
+  rx_sdu.reset();
+
+  // Drop all messages in RX window
+  rx_window.clear();
+}
+
+void rlc_um_lte::rlc_um_lte_rx::handle_data_pdu(uint8_t* payload, uint32_t nof_bytes)
+{
+  std::lock_guard<std::mutex> lock(mutex);
+
+  rlc_umd_pdu_header_t header;
+  rlc_um_read_data_pdu_header(payload, nof_bytes, cfg.um.rx_sn_field_length, &header);
+  log->info_hex(payload, nof_bytes, "RX %s Rx data PDU SN: %d (%d B)", rb_name.c_str(), header.sn, nof_bytes);
+
+  if (RX_MOD_BASE(header.sn) >= RX_MOD_BASE(vr_uh - cfg.um.rx_window_size) &&
+      RX_MOD_BASE(header.sn) < RX_MOD_BASE(vr_ur)) {
+    log->info("%s SN: %d outside rx window [%d:%d] - discarding\n", rb_name.c_str(), header.sn, vr_ur, vr_uh);
+    return;
+  }
+
+  std::map<uint32_t, rlc_umd_pdu_t>::iterator it = rx_window.find(header.sn);
+  if (rx_window.end() != it) {
+    log->info("%s Discarding duplicate SN: %d\n", rb_name.c_str(), header.sn);
+    return;
+  }
+
+  // Write to rx window
+  rlc_umd_pdu_t pdu = {};
+  pdu.buf           = allocate_unique_buffer(*pool);
+  if (!pdu.buf) {
+    log->error("Discarting packet: no space in buffer pool\n");
+    return;
+  }
+  memcpy(pdu.buf->msg, payload, nof_bytes);
+  pdu.buf->N_bytes = nof_bytes;
+  // Strip header from PDU
+  int header_len = rlc_um_packed_length(&header);
+  pdu.buf->msg += header_len;
+  pdu.buf->N_bytes -= header_len;
+  pdu.header           = header;
+  rx_window[header.sn] = std::move(pdu);
+
+  // Update vr_uh
+  if (!inside_reordering_window(header.sn)) {
+    vr_uh = (header.sn + 1) % cfg.um.rx_mod;
+  }
+
+  // Reassemble and deliver SDUs, while updating vr_ur
+  log->debug("Entering Reassemble from received PDU\n");
+  reassemble_rx_sdus();
+  log->debug("Finished reassemble from received PDU\n");
+
+  // Update reordering variables and timers
+  if (reordering_timer.is_running()) {
+    if (RX_MOD_BASE(vr_ux) <= RX_MOD_BASE(vr_ur) || (!inside_reordering_window(vr_ux) && vr_ux != vr_uh)) {
+      reordering_timer.stop();
+    }
+  }
+  if (!reordering_timer.is_running()) {
+    if (RX_MOD_BASE(vr_uh) > RX_MOD_BASE(vr_ur)) {
+      reordering_timer.run();
+      vr_ux = vr_uh;
+    }
+  }
+
+  debug_state();
+}
+
+// No locking required as only called from within handle_data_pdu and timer_expired which lock
+void rlc_um_lte::rlc_um_lte_rx::reassemble_rx_sdus()
+{
+  if (!rx_sdu) {
+    rx_sdu = allocate_unique_buffer(*pool);
+    if (!rx_sdu) {
+      log->error("Fatal Error: Couldn't allocate buffer in rlc_um::reassemble_rx_sdus().\n");
+      return;
+    }
+  }
+
+  // First catch up with lower edge of reordering window
+  while (!inside_reordering_window(vr_ur)) {
+    log->debug("SN=%d is not inside reordering windows\n", vr_ur);
+
+    if (rx_window.end() == rx_window.find(vr_ur)) {
+      log->debug("SN=%d not in rx_window. Reset received SDU\n", vr_ur);
+      rx_sdu->clear();
+    } else {
+      // Handle any SDU segments
+      for (uint32_t i = 0; i < rx_window[vr_ur].header.N_li; i++) {
+        int len = rx_window[vr_ur].header.li[i];
+        log->debug_hex(rx_window[vr_ur].buf->msg,
+                       len,
+                       "Handling segment %d/%d of length %d B of SN=%d\n",
+                       i + 1,
+                       rx_window[vr_ur].header.N_li,
+                       len,
+                       vr_ur);
+        // Check if we received a middle or end segment
+        if (rx_sdu->N_bytes == 0 && i == 0 && !rlc_um_start_aligned(rx_window[vr_ur].header.fi)) {
+          log->warning("Dropping PDU %d due to lost start segment\n", vr_ur);
+          // Advance data pointers and continue with next segment
+          rx_window[vr_ur].buf->msg += len;
+          rx_window[vr_ur].buf->N_bytes -= len;
+          rx_sdu->clear();
+          break;
+        }
+
+        memcpy(&rx_sdu->msg[rx_sdu->N_bytes], rx_window[vr_ur].buf->msg, len);
+        rx_sdu->N_bytes += len;
+        rx_window[vr_ur].buf->msg += len;
+        rx_window[vr_ur].buf->N_bytes -= len;
+        if ((pdu_lost && !rlc_um_start_aligned(rx_window[vr_ur].header.fi)) ||
+            (vr_ur != ((vr_ur_in_rx_sdu + 1) % cfg.um.rx_mod))) {
+          log->warning("Dropping remainder of lost PDU (lower edge middle segments, vr_ur=%d, vr_ur_in_rx_sdu=%d)\n",
+                       vr_ur,
+                       vr_ur_in_rx_sdu);
+          rx_sdu->clear();
+        } else {
+          log->info_hex(rx_sdu->msg,
+                        rx_sdu->N_bytes,
+                        "%s Rx SDU vr_ur=%d, i=%d (lower edge middle segments)",
+                        rb_name.c_str(),
+                        vr_ur,
+                        i);
+          rx_sdu->set_timestamp();
+          if (cfg.um.is_mrb) {
+            pdcp->write_pdu_mch(lcid, std::move(rx_sdu));
+          } else {
+            pdcp->write_pdu(lcid, std::move(rx_sdu));
+          }
+          rx_sdu = allocate_unique_buffer(*pool);
+          if (!rx_sdu) {
+            log->error("Fatal Error: Couldn't allocate buffer in rlc_um::reassemble_rx_sdus().\n");
+            return;
+          }
+        }
+        pdu_lost = false;
+      }
+
+      // Handle last segment
+      if (rx_sdu->N_bytes > 0 || rlc_um_start_aligned(rx_window[vr_ur].header.fi)) {
+        log->info("Writing last segment in SDU buffer. Lower edge vr_ur=%d, Buffer size=%d, segment size=%d\n",
+                  vr_ur,
+                  rx_sdu->N_bytes,
+                  rx_window[vr_ur].buf->N_bytes);
+
+        memcpy(&rx_sdu->msg[rx_sdu->N_bytes], rx_window[vr_ur].buf->msg, rx_window[vr_ur].buf->N_bytes);
+        rx_sdu->N_bytes += rx_window[vr_ur].buf->N_bytes;
+        vr_ur_in_rx_sdu = vr_ur;
+        if (rlc_um_end_aligned(rx_window[vr_ur].header.fi)) {
+          if (pdu_lost && !rlc_um_start_aligned(rx_window[vr_ur].header.fi)) {
+            log->warning("Dropping remainder of lost PDU (lower edge last segments)\n");
+            rx_sdu->clear();
+          } else {
+            log->info_hex(
+                rx_sdu->msg, rx_sdu->N_bytes, "%s Rx SDU vr_ur=%d (lower edge last segments)", rb_name.c_str(), vr_ur);
+            rx_sdu->set_timestamp();
+            if (cfg.um.is_mrb) {
+              pdcp->write_pdu_mch(lcid, std::move(rx_sdu));
+            } else {
+              pdcp->write_pdu(lcid, std::move(rx_sdu));
+            }
+            rx_sdu = allocate_unique_buffer(*pool);
+            if (!rx_sdu) {
+              log->error("Fatal Error: Couldn't allocate buffer in rlc_um::reassemble_rx_sdus().\n");
+              return;
+            }
+          }
+          pdu_lost = false;
+        }
+      }
+
+      // Clean up rx_window
+      rx_window.erase(vr_ur);
+    }
+
+    vr_ur = (vr_ur + 1) % cfg.um.rx_mod;
+  }
+
+  // Now update vr_ur until we reach an SN we haven't yet received
+  while (rx_window.end() != rx_window.find(vr_ur)) {
+    log->debug("Reassemble loop for vr_ur=%d\n", vr_ur);
+
+    if (not pdu_belongs_to_rx_sdu()) {
+      log->warning(
+          "PDU SN=%d lost, stop reassambling SDU (vr_ur_in_rx_sdu=%d)\n", vr_ur_in_rx_sdu + 1, vr_ur_in_rx_sdu);
+      pdu_lost = false; // Reset flag to not prevent reassembling of further segments
+      rx_sdu->clear();
+    }
+
+    // Handle any SDU segments
+    for (uint32_t i = 0; i < rx_window[vr_ur].header.N_li; i++) {
+      uint16_t len = rx_window[vr_ur].header.li[i];
+      log->debug("Handling SDU segment i=%d with len=%d of vr_ur=%d N_li=%d [%s]\n",
+                 i,
+                 len,
+                 vr_ur,
+                 rx_window[vr_ur].header.N_li,
+                 rlc_fi_field_text[rx_window[vr_ur].header.fi]);
+      // Check if the first part of the PDU is a middle or end segment
+      if (rx_sdu->N_bytes == 0 && i == 0 && !rlc_um_start_aligned(rx_window[vr_ur].header.fi)) {
+        log->warning_hex(
+            rx_window[vr_ur].buf->msg, len, "Dropping first %d B of SN %d due to lost start segment\n", len, vr_ur);
+
+        if (rx_window[vr_ur].buf->N_bytes < len) {
+          log->error("Dropping remaining remainder of SN %d too (N_bytes=%u < len=%d)\n",
+                     vr_ur,
+                     rx_window[vr_ur].buf->N_bytes,
+                     len);
+          goto clean_up_rx_window;
+        }
+
+        // Advance data pointers and continue with next segment
+        rx_window[vr_ur].buf->msg += len;
+        rx_window[vr_ur].buf->N_bytes -= len;
+        rx_sdu->clear();
+
+        // Reset flag, it is safe to process all remaining segments of this PDU
+        pdu_lost = false;
+        continue;
+      }
+
+      // Check available space in SDU
+      if ((uint32_t)len > rx_sdu->get_tailroom()) {
+        log->error("Dropping PDU %d due to buffer mis-alignment (current segment len %d B, received %d B)\n",
+                   vr_ur,
+                   rx_sdu->N_bytes,
+                   len);
+        rx_sdu->clear();
+        goto clean_up_rx_window;
+      }
+
+      if (not pdu_belongs_to_rx_sdu()) {
+        log->info_hex(rx_window[vr_ur].buf->msg, len, "Copying first %d bytes of new SDU\n", len);
+        log->info("Updating vr_ur_in_rx_sdu. old=%d, new=%d\n", vr_ur_in_rx_sdu, vr_ur);
+        vr_ur_in_rx_sdu = vr_ur;
+      } else {
+        log->info_hex(rx_window[vr_ur].buf->msg,
+                      len,
+                      "Concatenating %d bytes in to current length %d. rx_window remaining bytes=%d, "
+                      "vr_ur_in_rx_sdu=%d, vr_ur=%d, rx_mod=%d, last_mod=%d\n",
+                      len,
+                      rx_sdu->N_bytes,
+                      rx_window[vr_ur].buf->N_bytes,
+                      vr_ur_in_rx_sdu,
+                      vr_ur,
+                      cfg.um.rx_mod,
+                      (vr_ur_in_rx_sdu + 1) % cfg.um.rx_mod);
+      }
+
+      memcpy(&rx_sdu->msg[rx_sdu->N_bytes], rx_window[vr_ur].buf->msg, len);
+      rx_sdu->N_bytes += len;
+      rx_window[vr_ur].buf->msg += len;
+      rx_window[vr_ur].buf->N_bytes -= len;
+      vr_ur_in_rx_sdu = vr_ur;
+
+      if (pdu_belongs_to_rx_sdu()) {
+        log->info_hex(rx_sdu->msg,
+                      rx_sdu->N_bytes,
+                      "%s Rx SDU vr_ur=%d, i=%d, (update vr_ur middle segments)",
+                      rb_name.c_str(),
+                      vr_ur,
+                      i);
+        rx_sdu->set_timestamp();
+        if (cfg.um.is_mrb) {
+          pdcp->write_pdu_mch(lcid, std::move(rx_sdu));
+        } else {
+          pdcp->write_pdu(lcid, std::move(rx_sdu));
+        }
+        rx_sdu = allocate_unique_buffer(*pool);
+        if (!rx_sdu) {
+          log->error("Fatal Error: Couldn't allocate buffer in rlc_um::reassemble_rx_sdus().\n");
+          return;
+        }
+      } else {
+        log->warning("Dropping remainder of lost PDU (update vr_ur middle segments, vr_ur=%d, vr_ur_in_rx_sdu=%d)\n",
+                     vr_ur,
+                     vr_ur_in_rx_sdu);
+        // Advance data pointers and continue with next segment
+        rx_window[vr_ur].buf->msg += len;
+        rx_window[vr_ur].buf->N_bytes -= len;
+      }
+      pdu_lost = false;
+    }
+
+    // Handle last segment
+    if (rx_sdu->N_bytes == 0 && rx_window[vr_ur].header.N_li == 0 &&
+        !rlc_um_start_aligned(rx_window[vr_ur].header.fi)) {
+      log->warning("Dropping PDU %d due to lost start segment\n", vr_ur);
+      rx_sdu->clear();
+      goto clean_up_rx_window;
+    }
+
+    if (rx_sdu->N_bytes < SRSLTE_MAX_BUFFER_SIZE_BYTES &&
+        rx_window[vr_ur].buf->N_bytes < SRSLTE_MAX_BUFFER_SIZE_BYTES &&
+        rx_window[vr_ur].buf->N_bytes + rx_sdu->N_bytes < SRSLTE_MAX_BUFFER_SIZE_BYTES) {
+      log->info_hex(rx_window[vr_ur].buf->msg,
+                    rx_window[vr_ur].buf->N_bytes,
+                    "Writing last segment in SDU buffer. Updating vr_ur=%d, vr_ur_in_rx_sdu=%d, Buffer size=%d, "
+                    "segment size=%d\n",
+                    vr_ur,
+                    vr_ur_in_rx_sdu,
+                    rx_sdu->N_bytes,
+                    rx_window[vr_ur].buf->N_bytes);
+      memcpy(&rx_sdu->msg[rx_sdu->N_bytes], rx_window[vr_ur].buf->msg, rx_window[vr_ur].buf->N_bytes);
+      rx_sdu->N_bytes += rx_window[vr_ur].buf->N_bytes;
+    } else {
+      log->error("Out of bounds while reassembling SDU buffer in UM: sdu_len=%d, window_buffer_len=%d, vr_ur=%d\n",
+                 rx_sdu->N_bytes,
+                 rx_window[vr_ur].buf->N_bytes,
+                 vr_ur);
+    }
+    vr_ur_in_rx_sdu = vr_ur;
+    if (rlc_um_end_aligned(rx_window[vr_ur].header.fi)) {
+      if (pdu_lost && !rlc_um_start_aligned(rx_window[vr_ur].header.fi)) {
+        log->warning("Dropping remainder of lost PDU (update vr_ur last segments)\n");
+        rx_sdu->clear();
+      } else {
+        log->info_hex(
+            rx_sdu->msg, rx_sdu->N_bytes, "%s Rx SDU vr_ur=%d (update vr_ur last segments)", rb_name.c_str(), vr_ur);
+        rx_sdu->set_timestamp();
+        if (cfg.um.is_mrb) {
+          pdcp->write_pdu_mch(lcid, std::move(rx_sdu));
+        } else {
+          pdcp->write_pdu(lcid, std::move(rx_sdu));
+        }
+        rx_sdu = allocate_unique_buffer(*pool);
+        if (!rx_sdu) {
+          log->error("Fatal Error: Couldn't allocate buffer in rlc_um::reassemble_rx_sdus().\n");
+          return;
+        }
+      }
+      pdu_lost = false;
+    }
+
+  clean_up_rx_window:
+    // Clean up rx_window
+    rx_window.erase(vr_ur);
+
+    vr_ur = (vr_ur + 1) % cfg.um.rx_mod;
+  }
+}
+
+// Only called when lock is hold
+bool rlc_um_lte::rlc_um_lte_rx::pdu_belongs_to_rx_sdu()
+{
+  // return true if the currently received SDU
+  if (((vr_ur_in_rx_sdu + 1) % cfg.um.rx_mod == vr_ur) || (vr_ur == vr_ur_in_rx_sdu)) {
+    return true;
+  }
+  return false;
+}
+
+// Only called when lock is hold
+// 36.322 Section 5.1.2.2.1
+bool rlc_um_lte::rlc_um_lte_rx::inside_reordering_window(uint16_t sn)
+{
+  if (cfg.um.rx_window_size == 0 || rx_window.empty()) {
+    return true;
+  }
+  if (RX_MOD_BASE(vr_uh - cfg.um.rx_window_size) <= RX_MOD_BASE(sn) && RX_MOD_BASE(sn) < RX_MOD_BASE(vr_uh)) {
+    return true;
+  } else {
+    return false;
+  }
+}
+
+/****************************************************************************
+ * Timeout callback interface
+ ***************************************************************************/
+
+void rlc_um_lte::rlc_um_lte_rx::timer_expired(uint32_t timeout_id)
+{
+  std::lock_guard<std::mutex> lock(mutex);
+  if (reordering_timer.id() == timeout_id) {
+    // 36.322 v10 Section 5.1.2.2.4
+    log->info("%s reordering timeout expiry - updating vr_ur and reassembling\n", rb_name.c_str());
+
+    log->warning("Lost PDU SN: %d\n", vr_ur);
+
+    pdu_lost = true;
+    if (rx_sdu != NULL) {
+      rx_sdu->clear();
+    }
+
+    while (RX_MOD_BASE(vr_ur) < RX_MOD_BASE(vr_ux)) {
+      vr_ur = (vr_ur + 1) % cfg.um.rx_mod;
+      log->debug("Entering Reassemble from timeout id=%d\n", timeout_id);
+      reassemble_rx_sdus();
+      log->debug("Finished reassemble from timeout id=%d\n", timeout_id);
+    }
+
+    if (RX_MOD_BASE(vr_uh) > RX_MOD_BASE(vr_ur)) {
+      reordering_timer.run();
+      vr_ux = vr_uh;
+    }
+
+    debug_state();
+  }
+}
+
+/****************************************************************************
+ * Helper functions
+ ***************************************************************************/
+
+void rlc_um_lte::rlc_um_lte_rx::debug_state()
+{
+  log->debug("%s vr_ur = %d, vr_ux = %d, vr_uh = %d\n", rb_name.c_str(), vr_ur, vr_ux, vr_uh);
+}
+
+/****************************************************************************
+ * Header pack/unpack helper functions
+ * Ref: 3GPP TS 36.322 v10.0.0 Section 6.2.1
+ ***************************************************************************/
+
+void rlc_um_read_data_pdu_header(byte_buffer_t* pdu, rlc_umd_sn_size_t sn_size, rlc_umd_pdu_header_t* header)
+{
+  rlc_um_read_data_pdu_header(pdu->msg, pdu->N_bytes, sn_size, header);
+}
+
+void rlc_um_read_data_pdu_header(uint8_t*              payload,
+                                 uint32_t              nof_bytes,
+                                 rlc_umd_sn_size_t     sn_size,
+                                 rlc_umd_pdu_header_t* header)
+{
+  uint8_t  ext;
+  uint8_t* ptr = payload;
+  // Fixed part
+  if (sn_size == rlc_umd_sn_size_t::size5bits) {
+    header->fi = (rlc_fi_field_t)((*ptr >> 6) & 0x03); // 2 bits FI
+    ext        = ((*ptr >> 5) & 0x01);                 // 1 bit EXT
+    header->sn = *ptr & 0x1F;                          // 5 bits SN
+    ptr++;
+  } else {
+    header->fi = (rlc_fi_field_t)((*ptr >> 3) & 0x03); // 2 bits FI
+    ext        = ((*ptr >> 2) & 0x01);                 // 1 bit EXT
+    header->sn = (*ptr & 0x03) << 8;                   // 2 bits SN
+    ptr++;
+    header->sn |= (*ptr & 0xFF); // 8 bits SN
+    ptr++;
+  }
+
+  header->sn_size = sn_size;
+
+  // Extension part
+  header->N_li = 0;
+  while (ext) {
+    if (header->N_li % 2 == 0) {
+      ext                      = ((*ptr >> 7) & 0x01);
+      header->li[header->N_li] = (*ptr & 0x7F) << 4; // 7 bits of LI
+      ptr++;
+      header->li[header->N_li] |= (*ptr & 0xF0) >> 4; // 4 bits of LI
+      header->N_li++;
+    } else {
+      ext                      = (*ptr >> 3) & 0x01;
+      header->li[header->N_li] = (*ptr & 0x07) << 8; // 3 bits of LI
+      ptr++;
+      header->li[header->N_li] |= (*ptr & 0xFF); // 8 bits of LI
+      header->N_li++;
+      ptr++;
+    }
+  }
+}
+
+void rlc_um_write_data_pdu_header(rlc_umd_pdu_header_t* header, byte_buffer_t* pdu)
+{
+  uint32_t i;
+  uint8_t  ext = (header->N_li > 0) ? 1 : 0;
+  // Make room for the header
+  uint32_t len = rlc_um_packed_length(header);
+  pdu->msg -= len;
+  uint8_t* ptr = pdu->msg;
+
+  // Fixed part
+  if (header->sn_size == rlc_umd_sn_size_t::size5bits) {
+    *ptr = (header->fi & 0x03) << 6; // 2 bits FI
+    *ptr |= (ext & 0x01) << 5;       // 1 bit EXT
+    *ptr |= header->sn & 0x1F;       // 5 bits SN
+    ptr++;
+  } else {
+    *ptr = (header->fi & 0x03) << 3;   // 3 Reserved bits | 2 bits FI
+    *ptr |= (ext & 0x01) << 2;         // 1 bit EXT
+    *ptr |= (header->sn & 0x300) >> 8; // 2 bits SN
+    ptr++;
+    *ptr = (header->sn & 0xFF); // 8 bits SN
+    ptr++;
+  }
+
+  // Extension part
+  i = 0;
+  while (i < header->N_li) {
+    ext  = ((i + 1) == header->N_li) ? 0 : 1;
+    *ptr = (ext & 0x01) << 7;             // 1 bit header
+    *ptr |= (header->li[i] & 0x7F0) >> 4; // 7 bits of LI
+    ptr++;
+    *ptr = (header->li[i] & 0x00F) << 4; // 4 bits of LI
+    i++;
+    if (i < header->N_li) {
+      ext = ((i + 1) == header->N_li) ? 0 : 1;
+      *ptr |= (ext & 0x01) << 3;            // 1 bit header
+      *ptr |= (header->li[i] & 0x700) >> 8; // 3 bits of LI
+      ptr++;
+      *ptr = (header->li[i] & 0x0FF); // 8 bits of LI
+      ptr++;
+      i++;
+    }
+  }
+  // Pad if N_li is odd
+  if (header->N_li % 2 == 1)
+    ptr++;
+
+  pdu->N_bytes += ptr - pdu->msg;
+}
+
+uint32_t rlc_um_packed_length(rlc_umd_pdu_header_t* header)
+{
+  uint32_t len = 0;
+  if (header->sn_size == rlc_umd_sn_size_t::size5bits) {
+    len += 1; // Fixed part is 1 byte
+  } else {
+    len += 2; // Fixed part is 2 bytes
+  }
+  len += header->N_li * 1.5 + 0.5; // Extension part - integer rounding up
+  return len;
+}
+
+bool rlc_um_start_aligned(uint8_t fi)
+{
+  return (fi == RLC_FI_FIELD_START_AND_END_ALIGNED || fi == RLC_FI_FIELD_NOT_END_ALIGNED);
+}
+
+bool rlc_um_end_aligned(uint8_t fi)
+{
+  return (fi == RLC_FI_FIELD_START_AND_END_ALIGNED || fi == RLC_FI_FIELD_NOT_START_ALIGNED);
+}
+
+} // namespace srslte

lib/src/upper/rlc_um_nr.cc

@@ -0,0 +1,688 @@
+/*
+ * Copyright 2013-2019 Software Radio Systems Limited
+ *
+ * This file is part of srsLTE.
+ *
+ * srsLTE is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * srsLTE is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * A copy of the GNU Affero General Public License can be found in
+ * the LICENSE file in the top-level directory of this distribution
+ * and at http://www.gnu.org/licenses/.
+ *
+ */
+
+#include "srslte/upper/rlc_um_nr.h"
+#include <sstream>
+
+#define RX_MOD_NR_BASE(x) (((x)-RX_Next_Highest - cfg.um_nr.UM_Window_Size) % cfg.um_nr.mod)
+
+using namespace asn1::rrc;
+
+namespace srslte {
+
+rlc_um_nr::rlc_um_nr(srslte::log*               log_,
+                     uint32_t                   lcid_,
+                     srsue::pdcp_interface_rlc* pdcp_,
+                     srsue::rrc_interface_rlc*  rrc_,
+                     srslte::timer_handler*     timers_) :
+  rlc_um_base(log_, lcid_, pdcp_, rrc_, timers_)
+{
+}
+
+rlc_um_nr::~rlc_um_nr()
+{
+  stop();
+}
+
+bool rlc_um_nr::configure(rlc_config_t cnfg_)
+{
+  // determine bearer name and configure Rx/Tx objects
+  rb_name = get_rb_name(rrc, lcid, cnfg_.um.is_mrb);
+
+  // store config
+  cfg = cnfg_;
+
+  rx.reset(new rlc_um_nr_rx(this));
+  if (not rx->configure()) {
+    return false;
+  }
+
+  tx.reset(new rlc_um_nr_tx(this));
+  if (not tx->configure(cfg, rb_name)) {
+    return false;
+  }
+
+  log->info("%s configured in %s: sn_field_length=%u bits\n",
+            rb_name.c_str(),
+            srslte::to_string(cnfg_.rlc_mode).c_str(),
+            srslte::to_number(cfg.um_nr.sn_field_length));
+
+  rx_enabled = true;
+  tx_enabled = true;
+
+  return true;
+}
+
+/****************************************************************************
+ * Tx Subclass implementation
+ ***************************************************************************/
+
+rlc_um_nr::rlc_um_nr_tx::rlc_um_nr_tx(rlc_um_base* parent_) : rlc_um_base_tx(parent_) {}
+
+uint32_t rlc_um_nr::rlc_um_nr_tx::get_buffer_state()
+{
+  std::lock_guard<std::mutex> lock(mutex);
+
+  // Bytes needed for tx SDUs
+  uint32_t n_sdus  = tx_sdu_queue.size();
+  uint32_t n_bytes = tx_sdu_queue.size_bytes();
+  if (tx_sdu) {
+    n_sdus++;
+    n_bytes += tx_sdu->N_bytes;
+  }
+
+  // Room needed for header extensions? (integer rounding)
+  if (n_sdus > 1) {
+    n_bytes += ((n_sdus - 1) * 1.5) + 0.5;
+  }
+
+  // Room needed for fixed header?
+  if (n_bytes > 0)
+    n_bytes += (cfg.um.is_mrb) ? 2 : 3;
+
+  return n_bytes;
+}
+
+bool rlc_um_nr::rlc_um_nr_tx::configure(rlc_config_t cnfg_, std::string rb_name_)
+{
+  cfg = cnfg_;
+
+  if (cfg.um_nr.mod == 0) {
+    log->error("Error configuring %s RLC UM: tx_mod==0\n", rb_name.c_str());
+    return false;
+  }
+
+  tx_sdu_queue.resize(cnfg_.tx_queue_length);
+
+  rb_name    = rb_name_;
+
+  return true;
+}
+
+int rlc_um_nr::rlc_um_nr_tx::build_data_pdu(unique_byte_buffer_t pdu, uint8_t* payload, uint32_t nof_bytes)
+{
+  std::lock_guard<std::mutex> lock(mutex);
+  rlc_um_nr_pdu_header_t      header = {};
+  header.si                          = rlc_nr_si_field_t::full_sdu;
+  header.sn                          = TX_Next;
+  header.sn_size                     = cfg.um_nr.sn_field_length;
+
+  uint32_t to_move = 0;
+  uint8_t* pdu_ptr = pdu->msg;
+
+  int head_len  = rlc_um_nr_packed_length(header);
+  int pdu_space = SRSLTE_MIN(nof_bytes, pdu->get_tailroom());
+
+  if (pdu_space <= head_len + 1) {
+    log->warning("%s Cannot build a PDU - %d bytes available, %d bytes required for header\n",
+                 rb_name.c_str(),
+                 nof_bytes,
+                 head_len);
+    return 0;
+  }
+
+  // Check for SDU segment
+  if (tx_sdu) {
+    uint32_t space = pdu_space - head_len;
+    to_move        = space >= tx_sdu->N_bytes ? tx_sdu->N_bytes : space;
+    log->debug(
+        "%s adding remainder of SDU segment - %d bytes of %d remaining\n", rb_name.c_str(), to_move, tx_sdu->N_bytes);
+    memcpy(pdu_ptr, tx_sdu->msg, to_move);
+    pdu_ptr += to_move;
+    pdu->N_bytes += to_move;
+    tx_sdu->N_bytes -= to_move;
+    tx_sdu->msg += to_move;
+    if (tx_sdu->N_bytes == 0) {
+      log->debug(
+          "%s Complete SDU scheduled for tx. Stack latency: %ld us\n", rb_name.c_str(), tx_sdu->get_latency_us());
+      tx_sdu.reset();
+      header.si = rlc_nr_si_field_t::last_segment;
+    } else {
+      header.si = rlc_nr_si_field_t::neither_first_nor_last_segment;
+    }
+    pdu_space -= SRSLTE_MIN(to_move, pdu->get_tailroom());
+    header.so = next_so;
+  } else {
+    // Pull SDU from queue
+    log->debug("pdu_space=%d, head_len=%d\n", pdu_space, head_len);
+
+    head_len       = rlc_um_nr_packed_length(header);
+    tx_sdu         = tx_sdu_queue.read();
+    uint32_t space = pdu_space - head_len;
+    to_move        = space >= tx_sdu->N_bytes ? tx_sdu->N_bytes : space;
+    log->debug("%s adding new SDU - %d bytes of %d remaining\n", rb_name.c_str(), to_move, tx_sdu->N_bytes);
+    memcpy(pdu_ptr, tx_sdu->msg, to_move);
+    pdu_ptr += to_move;
+    pdu->N_bytes += to_move;
+    tx_sdu->N_bytes -= to_move;
+    tx_sdu->msg += to_move;
+    if (tx_sdu->N_bytes == 0) {
+      log->debug(
+          "%s Complete SDU scheduled for tx. Stack latency: %ld us\n", rb_name.c_str(), tx_sdu->get_latency_us());
+      tx_sdu.reset();
+      header.si = rlc_nr_si_field_t::full_sdu;
+    } else {
+      header.si = rlc_nr_si_field_t::first_segment;
+    }
+    pdu_space -= to_move;
+  }
+
+  // advance SO offset
+  next_so += to_move;
+
+  // Update SN if needed
+  if (header.si == rlc_nr_si_field_t::last_segment) {
+    TX_Next        = (TX_Next + 1) % cfg.um_nr.mod;
+    next_so        = 0;
+  }
+
+  // Add header and TX
+  rlc_um_nr_write_data_pdu_header(header, pdu.get());
+  memcpy(payload, pdu->msg, pdu->N_bytes);
+  uint32_t ret = pdu->N_bytes;
+
+  log->info_hex(payload, ret, "%s Tx PDU SN=%d (%d B)\n", rb_name.c_str(), header.sn, pdu->N_bytes);
+
+  debug_state();
+
+  return ret;
+}
+
+void rlc_um_nr::rlc_um_nr_tx::debug_state()
+{
+  log->debug("%s TX_Next = %d\n", rb_name.c_str(), TX_Next);
+}
+
+/****************************************************************************
+ * Rx Subclass implementation
+ ***************************************************************************/
+
+rlc_um_nr::rlc_um_nr_rx::rlc_um_nr_rx(rlc_um_base* parent_) :
+  rlc_um_base_rx(parent_), reassembly_timer(timers->get_unique_timer())
+{
+}
+
+bool rlc_um_nr::rlc_um_nr_rx::configure()
+{
+  if (cfg.um_nr.mod == 0) {
+    log->error("Error configuring %s RLC UM: rx_mod==0\n", rb_name.c_str());
+    return false;
+  }
+
+  // check timer
+  if (not reassembly_timer.is_valid()) {
+    log->error("Configuring RLC UM NR RX: timers not configured\n");
+    return false;
+  }
+
+  // configure timer
+  if (cfg.um_nr.t_reassembly_ms > 0) {
+    reassembly_timer.set(static_cast<uint32_t>(cfg.um_nr.t_reassembly_ms),
+                         [this](uint32_t tid) { timer_expired(tid); });
+  }
+
+  return true;
+}
+
+void rlc_um_nr::rlc_um_nr_rx::stop()
+{
+  std::lock_guard<std::mutex> lock(mutex);
+  reset();
+  reassembly_timer.stop();
+}
+
+void rlc_um_nr::rlc_um_nr_rx::reset()
+{
+  RX_Next_Reassembly = 0;
+  RX_Timer_Trigger   = 0;
+  RX_Next_Highest    = 0;
+
+  rx_sdu.reset();
+
+  // Drop all messages in RX window
+  rx_window.clear();
+
+  // stop timer
+  if (reassembly_timer.is_valid()) {
+    reassembly_timer.stop();
+  }
+}
+
+// TS 38.322 Sec. 5.1.2
+void rlc_um_nr::rlc_um_nr_rx::reestablish()
+{
+  // drop all SDUs, SDU segments, PDUs and reset timers
+  reset();
+}
+
+// TS 38.322 v15.003 Section 5.2.2.2.4
+void rlc_um_nr::rlc_um_nr_rx::timer_expired(uint32_t timeout_id)
+{
+  std::lock_guard<std::mutex> lock(mutex);
+  if (reassembly_timer.id() == timeout_id) {
+    log->info("%s reassembly timeout expiry - updating RX_Next_Reassembly and reassembling\n", rb_name.c_str());
+
+    log->warning("Lost PDU SN: %d\n", RX_Next_Reassembly);
+    metrics.num_lost_pdus++;
+
+    if (rx_sdu != nullptr) {
+      rx_sdu->clear();
+    }
+
+    // update RX_Next_Reassembly to the next SN that has not been reassembled yet
+    RX_Next_Reassembly = RX_Timer_Trigger;
+    while (RX_MOD_NR_BASE(RX_Next_Reassembly) < RX_MOD_NR_BASE(RX_Next_Highest)) {
+      RX_Next_Reassembly = (RX_Next_Reassembly + 1) % cfg.um_nr.mod;
+      debug_state();
+    }
+
+    // discard all segments with SN < updated RX_Next_Reassembly
+    for (auto it = rx_window.begin(); it != rx_window.end();) {
+      if (it->first < RX_Next_Reassembly) {
+        it = rx_window.erase(it);
+      } else {
+        ++it;
+      }
+    }
+
+    // check start of t_reassembly
+    if (RX_MOD_NR_BASE(RX_Next_Highest) > RX_MOD_NR_BASE(RX_Next_Reassembly + 1) ||
+        (RX_MOD_NR_BASE(RX_Next_Highest) == RX_MOD_NR_BASE(RX_Next_Reassembly + 1) &&
+         has_missing_byte_segment(RX_Next_Reassembly))) {
+      reassembly_timer.run();
+      RX_Timer_Trigger = RX_Next_Highest;
+    }
+
+    debug_state();
+  }
+}
+
+// Sec 5.2.2.2.1
+bool rlc_um_nr::rlc_um_nr_rx::sn_in_reassembly_window(const uint32_t sn)
+{
+  return (RX_MOD_NR_BASE(RX_Next_Highest - cfg.um_nr.UM_Window_Size) <= RX_MOD_NR_BASE(sn) &&
+          RX_MOD_NR_BASE(sn) < RX_MOD_NR_BASE(RX_Next_Highest));
+}
+
+// Sec 5.2.2.2.2
+bool rlc_um_nr::rlc_um_nr_rx::sn_invalid_for_rx_buffer(const uint32_t sn)
+{
+  return (RX_MOD_NR_BASE(RX_Next_Highest - cfg.um_nr.UM_Window_Size) <= RX_MOD_NR_BASE(sn) &&
+          RX_MOD_NR_BASE(sn) < RX_MOD_NR_BASE(RX_Next_Reassembly));
+}
+
+unique_byte_buffer_t rlc_um_nr::rlc_um_nr_rx::rlc_um_nr_strip_pdu_header(const rlc_um_nr_pdu_header_t& header,
+                                                                         const uint8_t*                payload,
+                                                                         const uint32_t                nof_bytes)
+{
+  unique_byte_buffer_t sdu = allocate_unique_buffer(*pool);
+  if (!sdu) {
+    log->error("Discarting packet: no space in buffer pool\n");
+    return nullptr;
+  }
+  memcpy(sdu->msg, payload, nof_bytes);
+  sdu->N_bytes = nof_bytes;
+
+  // strip RLC header
+  int header_len = rlc_um_nr_packed_length(header);
+  sdu->msg += header_len;
+  sdu->N_bytes -= header_len;
+  return sdu;
+}
+
+bool rlc_um_nr::rlc_um_nr_rx::has_missing_byte_segment(const uint32_t sn)
+{
+  // is at least one missing byte segment of the RLC SDU associated with SN = RX_Next_Reassembly before the last byte of
+  // all received segments of this RLC SDU
+  // FIXME: check assumption
+  // if SN can be found in rx_window, it means that at least one segment is missing
+  return (rx_window.find(sn) != rx_window.end());
+}
+
+// Sect 5.2.2.2.3
+void rlc_um_nr::rlc_um_nr_rx::handle_rx_buffer_update(const uint32_t sn)
+{
+  if (rx_window.find(sn) != rx_window.end()) {
+    // iterate over received segments and try to assemble full SDU
+    auto& pdu = rx_window.at(sn);
+    for (auto it = pdu.segments.begin(); it != pdu.segments.end();) {
+      log->debug("Have %s segment with SO=%d for SN=%d\n",
+                 to_string_short(it->second.header.si).c_str(),
+                 it->second.header.so,
+                 it->second.header.sn);
+      if (it->second.header.so == pdu.next_expected_so) {
+        if (pdu.next_expected_so == 0) {
+          if (pdu.sdu == nullptr) {
+            // reuse buffer of first segment for final SDU
+            pdu.sdu              = std::move(it->second.buf);
+            pdu.next_expected_so = pdu.sdu->N_bytes;
+            log->debug("Reusing first segment of SN=%d for final SDU\n", it->second.header.sn);
+            it = pdu.segments.erase(it);
+          } else {
+            log->debug("SDU buffer already allocated. Possible retransmission of first segment.\n");
+            if (it->second.header.so != pdu.next_expected_so) {
+              log->error("Invalid PDU. SO doesn't match. Discarting all segments of SN=%d.\n", sn);
+              rx_window.erase(sn);
+              return;
+            }
+          }
+        } else {
+          if (it->second.buf->N_bytes > pdu.sdu->get_tailroom()) {
+            log->error("Cannot fit RLC PDU in SDU buffer (tailroom=%d, len=%d), dropping both. Erasing SN=%d.\n",
+                       rx_sdu->get_tailroom(),
+                       it->second.buf->N_bytes,
+                       it->second.header.sn);
+            rx_window.erase(sn);
+            metrics.num_lost_pdus++;
+            return;
+          }
+
+          // add this segment to the end of the SDU buffer
+          memcpy(pdu.sdu->msg + pdu.sdu->N_bytes, it->second.buf->msg, it->second.buf->N_bytes);
+          pdu.sdu->N_bytes += it->second.buf->N_bytes;
+          pdu.next_expected_so += it->second.buf->N_bytes;
+          log->debug("Appended SO=%d of SN=%d\n", it->second.header.so, it->second.header.sn);
+          it = pdu.segments.erase(it);
+
+          if (pdu.next_expected_so == pdu.total_sdu_length) {
+            // deliver full SDU to upper layers
+            log->info("Delivering %s SDU SN=%d (%d B)", rb_name.c_str(), sn, pdu.sdu->N_bytes);
+            pdcp->write_pdu(lcid, std::move(pdu.sdu));
+
+            // find next SN in rx buffer
+            if (sn == RX_Next_Reassembly) {
+              RX_Next_Reassembly = ((RX_Next_Reassembly + 1) % cfg.um_nr.mod);
+              while (RX_MOD_NR_BASE(RX_Next_Reassembly) < RX_MOD_NR_BASE(RX_Next_Highest)) {
+                RX_Next_Reassembly = (RX_Next_Reassembly + 1) % cfg.um_nr.mod;
+              }
+              log->debug("Updating RX_Next_Reassembly=%d\n", RX_Next_Reassembly);
+            }
+
+            // delete PDU from rx_window
+            rx_window.erase(sn);
+            return;
+          }
+        }
+      } else {
+        // handle next segment
+        ++it;
+      }
+    }
+
+    // check for SN outside of rx window
+    if (not sn_in_reassembly_window(sn)) {
+      // update RX_Next_highest
+      RX_Next_Highest = sn + 1;
+      log->debug("Updating RX_Next_Highest=%d\n", RX_Next_Highest);
+
+      // drop all SNs outside of new rx window
+      for (auto it = rx_window.begin(); it != rx_window.end();) {
+        if (not sn_in_reassembly_window(it->first)) {
+          log->info("%s SN: %d outside rx window [%d:%d] - discarding\n",
+                    rb_name.c_str(),
+                    it->first,
+                    RX_Next_Highest - cfg.um_nr.UM_Window_Size,
+                    RX_Next_Highest);
+          it = rx_window.erase(it);
+          metrics.num_lost_pdus++;
+        } else {
+          ++it;
+        }
+      }
+
+      if (not sn_in_reassembly_window(RX_Next_Reassembly)) {
+        // update RX_Next_Reassembly to first SN that has not been reassembled and delivered
+        for (const auto& rx_pdu : rx_window) {
+          if (rx_pdu.first >= RX_MOD_NR_BASE(RX_Next_Highest - cfg.um_nr.UM_Window_Size)) {
+            RX_Next_Reassembly = rx_pdu.first;
+            log->debug("Updating RX_Next_Reassembly=%d\n", RX_Next_Reassembly);
+            break;
+          }
+        }
+      }
+
+      if (reassembly_timer.is_running()) {
+        if (RX_Timer_Trigger <= RX_Next_Reassembly ||
+            (not sn_in_reassembly_window(RX_Timer_Trigger) and RX_Timer_Trigger != RX_Next_Highest) ||
+            ((RX_Next_Highest == RX_Next_Reassembly + 1) && not has_missing_byte_segment(sn))) {
+          reassembly_timer.stop();
+        }
+      }
+
+      if (not reassembly_timer.is_running() && has_missing_byte_segment(sn)) {
+        if (RX_Next_Highest > RX_Next_Reassembly + 1) {
+          reassembly_timer.run();
+          RX_Timer_Trigger = RX_Next_Highest;
+        }
+      }
+    }
+  } else {
+    log->error("SN=%d does not exist in Rx buffer\n", sn);
+  }
+}
+
+inline void rlc_um_nr::rlc_um_nr_rx::update_total_sdu_length(rlc_umd_pdu_segments_nr_t& pdu_segments,
+                                                             const rlc_umd_pdu_nr_t&    rx_pdu)
+{
+  if (rx_pdu.header.si == rlc_nr_si_field_t::last_segment) {
+    pdu_segments.total_sdu_length = rx_pdu.header.so + rx_pdu.buf->N_bytes;
+    log->info("%s updating total SDU length for SN=%d to %d B\n",
+              rb_name.c_str(),
+              rx_pdu.header.sn,
+              pdu_segments.total_sdu_length);
+  }
+};
+
+// Section 5.2.2.2.2
+void rlc_um_nr::rlc_um_nr_rx::handle_data_pdu(uint8_t* payload, uint32_t nof_bytes)
+{
+  std::lock_guard<std::mutex> lock(mutex);
+
+  rlc_um_nr_pdu_header_t header = {};
+  rlc_um_nr_read_data_pdu_header(payload, nof_bytes, cfg.um_nr.sn_field_length, &header);
+  log->debug_hex(payload, nof_bytes, "RX %s Rx data PDU (%d B)", rb_name.c_str(), nof_bytes);
+
+  // check if PDU contains a SN
+  if (header.si == rlc_nr_si_field_t::full_sdu) {
+    // copy full PDU into buffer
+    unique_byte_buffer_t sdu = rlc_um_nr_strip_pdu_header(header, payload, nof_bytes);
+
+    // deliver to PDCP
+    log->info("Delivering %s SDU (%d B)", rb_name.c_str(), sdu->N_bytes);
+    pdcp->write_pdu(lcid, std::move(sdu));
+  } else if (sn_invalid_for_rx_buffer(header.sn)) {
+    log->info("%s Discarding SN=%d\n", rb_name.c_str(), header.sn);
+    // Nothing else to do here ..
+  } else {
+    // place PDU in receive buffer
+    rlc_umd_pdu_nr_t rx_pdu = {};
+    rx_pdu.header           = header;
+    rx_pdu.buf              = rlc_um_nr_strip_pdu_header(header, payload, nof_bytes);
+
+    // check if this SN is already present in rx buffer
+    if (rx_window.find(header.sn) == rx_window.end()) {
+      // first received segment of this SN, add to rx buffer
+      log->info("%s placing %s segment of SN=%d in Rx buffer\n",
+                rb_name.c_str(),
+                to_string_short(header.si).c_str(),
+                header.sn);
+      rlc_umd_pdu_segments_nr_t pdu_segments = {};
+      update_total_sdu_length(pdu_segments, rx_pdu);
+      pdu_segments.segments.emplace(header.so, std::move(rx_pdu));
+      rx_window[header.sn] = std::move(pdu_segments);
+    } else {
+      // other segment for this SN already present, update received data
+      log->info("%s updating SN=%d at SO=%d with %d B\n",
+                rb_name.c_str(),
+                rx_pdu.header.sn,
+                rx_pdu.header.so,
+                rx_pdu.buf->N_bytes);
+
+      auto& pdu_segments = rx_window.at(header.sn);
+
+      // calculate total SDU length
+      update_total_sdu_length(pdu_segments, rx_pdu);
+
+      // append to list of segments
+      pdu_segments.segments.emplace(header.so, std::move(rx_pdu));
+    }
+
+    // handle received segments
+    handle_rx_buffer_update(header.sn);
+  }
+
+  debug_state();
+}
+
+void rlc_um_nr::rlc_um_nr_rx::debug_state()
+{
+  log->debug("%s RX_Next_Reassembly=%d, RX_Timer_Trigger=%d, RX_Next_Highest=%d, t_Reassembly=%s\n",
+             rb_name.c_str(),
+             RX_Next_Reassembly,
+             RX_Timer_Trigger,
+             RX_Next_Highest,
+             reassembly_timer.is_running() ? "running" : "stopped");
+}
+/****************************************************************************
+ * Header pack/unpack helper functions
+ * Ref: 3GPP TS 38.322 v15.3.0 Section 6.2.2.3
+ ***************************************************************************/
+
+uint32_t rlc_um_nr_read_data_pdu_header(const byte_buffer_t*      pdu,
+                                        const rlc_um_nr_sn_size_t sn_size,
+                                        rlc_um_nr_pdu_header_t*   header)
+{
+  return rlc_um_nr_read_data_pdu_header(pdu->msg, pdu->N_bytes, sn_size, header);
+}
+
+uint32_t rlc_um_nr_read_data_pdu_header(const uint8_t*            payload,
+                                        const uint32_t            nof_bytes,
+                                        const rlc_um_nr_sn_size_t sn_size,
+                                        rlc_um_nr_pdu_header_t*   header)
+{
+  uint8_t* ptr = const_cast<uint8_t*>(payload);
+
+  header->sn_size = sn_size;
+
+  // Fixed part
+  if (sn_size == rlc_um_nr_sn_size_t::size6bits) {
+    header->si = (rlc_nr_si_field_t)((*ptr >> 6) & 0x03); // 2 bits SI
+    header->sn = *ptr & 0x3F;                             // 6 bits SN
+    // sanity check
+    if (header->si == rlc_nr_si_field_t::full_sdu and !(header->sn == 0)) {
+      fprintf(stderr, "Malformed PDU, reserved bits are set.\n");
+      return 0;
+    }
+    ptr++;
+  } else if (sn_size == rlc_um_nr_sn_size_t::size12bits) {
+    header->si = (rlc_nr_si_field_t)((*ptr >> 6) & 0x03); // 2 bits SI
+    header->sn = (*ptr & 0x0F) << 4;                      // 4 bits SN
+
+    // sanity check
+    if (header->si == rlc_nr_si_field_t::first_segment) {
+      // make sure two reserved bits are not set
+      if (((*ptr >> 4) & 0x03) != 0) {
+        fprintf(stderr, "Malformed PDU, reserved bits are set.\n");
+        return 0;
+      }
+    }
+
+    // continue unpacking remaining SN
+    ptr++;
+    header->sn |= (*ptr & 0xFF); // 8 bits SN
+    ptr++;
+  } else {
+    fprintf(stderr, "Unsupported SN length\n");
+    return 0;
+  }
+
+  // Read optional part
+  if (header->si == rlc_nr_si_field_t::last_segment ||
+      header->si == rlc_nr_si_field_t::neither_first_nor_last_segment) {
+    // read SO
+    header->so = (*ptr & 0xFF) << 8;
+    ptr++;
+    header->so |= (*ptr & 0xFF);
+    ptr++;
+  }
+
+  // return consumed bytes
+  return (ptr - payload);
+}
+
+uint32_t rlc_um_nr_packed_length(const rlc_um_nr_pdu_header_t& header)
+{
+  uint32_t len = 0;
+  if (header.si == rlc_nr_si_field_t::full_sdu || header.si == rlc_nr_si_field_t::first_segment) {
+    len = 1;
+    if (header.sn_size == rlc_um_nr_sn_size_t::size12bits) {
+      len++;
+    }
+  } else {
+    if (header.sn_size == rlc_um_nr_sn_size_t::size6bits) {
+      len = 3;
+    } else {
+      len = 4;
+    }
+  }
+  return len;
+}
+
+uint32_t rlc_um_nr_write_data_pdu_header(const rlc_um_nr_pdu_header_t& header, byte_buffer_t* pdu)
+{
+  // Make room for the header
+  uint32_t len = rlc_um_nr_packed_length(header);
+  pdu->msg -= len;
+  uint8_t* ptr = pdu->msg;
+
+  // write SI field
+  *ptr = (header.si & 0x03) << 6; // 2 bits SI
+
+  if (header.si == rlc_nr_si_field_t::full_sdu) {
+    // that's all ..
+    ptr++;
+  } else {
+    if (header.sn_size == rlc_um_nr_sn_size_t::size6bits) {
+      // write SN
+      *ptr |= (header.sn & 0x3f); // 6 bit SN
+      ptr++;
+    } else {
+      // 12bit SN
+      *ptr |= (header.sn & 0xf); // 4 bit SN
+      ptr++;
+      *ptr = (header.sn & 0xFF); // remaining 8 bit SN
+      ptr++;
+    }
+    if (header.so) {
+      // write SO
+      *ptr = (header.so) >> 8; // first part of SO
+      ptr++;
+      *ptr = (header.so & 0xFF); // second part of SO
+      ptr++;
+    }
+  }
+
+  pdu->N_bytes += ptr - pdu->msg;
+
+  return len;
+}
+
+} // namespace srslte

lib/test/upper/CMakeLists.txt

@@ -35,6 +35,7 @@ target_link_libraries(rlc_stress_test srslte_upper srslte_phy srslte_common ${Bo
 add_test(rlc_am_stress_test rlc_stress_test --mode=AM --loglevel 1 --sdu_gen_delay 250)
 add_test(rlc_um_stress_test rlc_stress_test --mode=UM --loglevel 1)
 add_test(rlc_tm_stress_test rlc_stress_test --mode=TM --loglevel 1 --random_opp=false)
+add_test(rlc_um_nr_stress_test rlc_stress_test --rat NR --mode=UM --loglevel 1)
 set_tests_properties(rlc_am_stress_test PROPERTIES TIMEOUT 3000)
 set_tests_properties(rlc_um_stress_test PROPERTIES TIMEOUT 3000)
 set_tests_properties(rlc_tm_stress_test PROPERTIES TIMEOUT 3000)

lib/test/upper/rlc_am_test.cc

@@ -146,6 +146,9 @@ bool basic_test()
   rlc_am_lte rlc1(&log1, 1, &tester, &tester, &timers);
   rlc_am_lte rlc2(&log2, 1, &tester, &tester, &timers);
 
+  // before configuring entity
+  assert(0 == rlc1.get_buffer_state());
+
   if (not rlc1.configure(rlc_config_t::default_rlc_am_config())) {
     return -1;
   }
@@ -181,10 +184,14 @@ bool basic_test()
   }
 
   // Check statistics
-  if (rlc1.get_num_tx_bytes() != rlc2.get_num_rx_bytes()) {
+  rlc_bearer_metrics_t rlc1_metrics = rlc1.get_metrics();
+  rlc_bearer_metrics_t rlc2_metrics = rlc2.get_metrics();
+
+  if (rlc1_metrics.num_tx_bytes != rlc2_metrics.num_rx_bytes) {
     return -1;
   }
-  if (rlc2.get_num_tx_bytes() != rlc1.get_num_rx_bytes()) {
+
+  if (rlc2_metrics.num_tx_bytes != rlc1_metrics.num_rx_bytes) {
     return -1;
   }
 
@@ -245,11 +252,15 @@ bool concat_test()
     assert(*(tester.sdus[i]->msg)  == i);
   }
 
-  // check statistics
+  // Check statistics
-  if (rlc1.get_num_tx_bytes() != rlc2.get_num_rx_bytes()) {
+  rlc_bearer_metrics_t rlc1_metrics = rlc1.get_metrics();
+  rlc_bearer_metrics_t rlc2_metrics = rlc2.get_metrics();
+
+  if (rlc1_metrics.num_tx_bytes != rlc2_metrics.num_rx_bytes) {
     return -1;
   }
-  if (rlc2.get_num_tx_bytes() != rlc1.get_num_rx_bytes()) {
+
+  if (rlc2_metrics.num_tx_bytes != rlc1_metrics.num_rx_bytes) {
     return -1;
   }
 
@@ -340,10 +351,15 @@ bool segment_test(bool in_seq_rx)
       assert(tester.sdus[i]->msg[j]  == j);
   }
 
-  if (rlc1.get_num_tx_bytes() != rlc2.get_num_rx_bytes()) {
+  // Check statistics
+  rlc_bearer_metrics_t rlc1_metrics = rlc1.get_metrics();
+  rlc_bearer_metrics_t rlc2_metrics = rlc2.get_metrics();
+
+  if (rlc1_metrics.num_tx_bytes != rlc2_metrics.num_rx_bytes) {
     return -1;
   }
-  if (rlc2.get_num_tx_bytes() != rlc1.get_num_rx_bytes()) {
+
+  if (rlc2_metrics.num_tx_bytes != rlc1_metrics.num_rx_bytes) {
     return -1;
   }
 

lib/test/upper/rlc_stress_test.cc

@@ -35,12 +35,44 @@
 
 #define LOG_HEX_LIMIT (-1)
 
+#define PCAP 1
+#define PCAP_CRNTI (0x1001)
+#define PCAP_TTI (666)
+
+#if PCAP
+#include "srslte/common/mac_nr_pcap.h"
+#include "srslte/common/mac_nr_pdu.h"
+static std::unique_ptr<srslte::mac_nr_pcap> pcap_handle = nullptr;
+#endif
+
+int write_pdu_to_pcap(const bool is_dl, const uint32_t lcid, const uint8_t* payload, const uint32_t len)
+{
+#if PCAP
+  if (pcap_handle) {
+    srslte::byte_buffer_t  tx_buffer;
+    srslte::mac_nr_sch_pdu tx_pdu;
+    tx_pdu.init_tx(&tx_buffer, len + 10);
+    tx_pdu.add_sdu(lcid, payload, len);
+    tx_pdu.pack();
+    if (is_dl) {
+      pcap_handle->write_dl_crnti(tx_buffer.msg, tx_buffer.N_bytes, PCAP_CRNTI, true, PCAP_TTI);
+    } else {
+      pcap_handle->write_ul_crnti(tx_buffer.msg, tx_buffer.N_bytes, PCAP_CRNTI, true, PCAP_TTI);
+    }
+
+    return SRSLTE_SUCCESS;
+  }
+#endif
+  return SRSLTE_ERROR;
+}
+
 using namespace std;
 using namespace srsue;
 using namespace srslte;
 namespace bpo = boost::program_options;
 
 typedef struct {
+  std::string rat;
   std::string mode;
   uint32_t    sdu_size;
   uint32_t    test_duration_sec;
@@ -72,6 +104,7 @@ void parse_args(stress_test_args_t *args, int argc, char *argv[]) {
   // Command line or config file options
   bpo::options_description common("Configuration options");
   common.add_options()
+  ("rat",          bpo::value<std::string>(&args->rat)->default_value("LTE"), "The RLC version to use (LTE/NR)")
   ("mode",          bpo::value<std::string>(&args->mode)->default_value("AM"), "Whether to test RLC acknowledged or unacknowledged mode (AM/UM)")
   ("duration",      bpo::value<uint32_t>(&args->test_duration_sec)->default_value(5), "Duration (sec)")
   ("sdu_size",      bpo::value<uint32_t>(&args->sdu_size)->default_value(1500), "Size of SDUs")
@@ -171,6 +204,8 @@ private:
           pdu_len = cut_pdu_len;
         }
         rx_rlc->write_pdu(lcid, pdu->msg, pdu_len);
+        write_pdu_to_pcap(is_dl, 4, pdu->msg, pdu_len);
+
         if (is_dl) {
           pcap->write_dl_am_ccch(pdu->msg, pdu_len);
         } else {
@@ -304,11 +339,8 @@ void stress_test(stress_test_args_t args)
   rlc_pcap pcap;
   uint32_t lcid = 1;
 
-  if (args.write_pcap) {
+  rlc_config_t cnfg_ = {};
-    pcap.open("rlc_stress_test.pcap", 0);
+  if (args.rat == "LTE") {
-  }
-
-  rlc_config_t cnfg_;
     if (args.mode == "AM") {
       // config RLC AM bearer
       cnfg_.rlc_mode             = rlc_mode_t::am;
@@ -335,6 +367,31 @@ void stress_test(stress_test_args_t args)
       exit(-1);
     }
 
+#if PCAP
+    if (args.write_pcap) {
+      pcap.open("rlc_stress_test.pcap", 0);
+    }
+#endif
+
+  } else if (args.rat == "NR") {
+    if (args.mode == "UM") {
+      cnfg_ = rlc_config_t::default_rlc_um_nr_config(6);
+    } else {
+      cout << "Unsupported RLC mode " << args.mode << ", exiting." << endl;
+      exit(-1);
+    }
+
+#if PCAP
+    if (args.write_pcap) {
+      pcap_handle = std::unique_ptr<srslte::mac_nr_pcap>(new srslte::mac_nr_pcap());
+      pcap_handle->open("rlc_stress_test_nr.pcap");
+    }
+#endif
+  } else {
+    cout << "Unsupported RAT mode " << args.rat << ", exiting." << endl;
+    exit(-1);
+  }
+
   srslte::timer_handler timers(8);
 
   rlc rlc1(&log1);
@@ -394,20 +451,20 @@ void stress_test(stress_test_args_t args)
   rlc_metrics_t metrics = {};
   rlc1.get_metrics(metrics);
 
-  printf("RLC1 received %d SDUs in %ds (%.2f/s), Throughput: DL=%4.2f Mbps, UL=%4.2f Mbps\n",
+  printf("RLC1 received %d SDUs in %ds (%.2f/s), Tx=%" PRIu64 " B, Rx=%" PRIu64 " B\n",
          tester1.get_nof_rx_pdus(),
          args.test_duration_sec,
          static_cast<double>(tester1.get_nof_rx_pdus() / args.test_duration_sec),
-         metrics.dl_tput_mbps[lcid],
+         metrics.bearer[lcid].num_tx_bytes,
-         metrics.ul_tput_mbps[lcid]);
+         metrics.bearer[lcid].num_rx_bytes);
 
   rlc2.get_metrics(metrics);
-  printf("RLC2 received %d SDUs in %ds (%.2f/s), Throughput: DL=%4.2f Mbps, UL=%4.2f Mbps\n",
+  printf("RLC2 received %d SDUs in %ds (%.2f/s), Tx=%" PRIu64 " B, Rx=%" PRIu64 " B\n",
          tester2.get_nof_rx_pdus(),
          args.test_duration_sec,
          static_cast<double>(tester2.get_nof_rx_pdus() / args.test_duration_sec),
-         metrics.dl_tput_mbps[lcid],
+         metrics.bearer[lcid].num_tx_bytes,
-         metrics.ul_tput_mbps[lcid]);
+         metrics.bearer[lcid].num_rx_bytes);
 }
 
 

lib/test/upper/rlc_test_common.h

@@ -35,10 +35,23 @@ public:
   // PDCP interface
   void write_pdu(uint32_t lcid, unique_byte_buffer_t sdu)
   {
+    // check length
     if (lcid != 3 && sdu->N_bytes != expected_sdu_len) {
       printf("Received PDU with size %d, expected %d. Exiting.\n", sdu->N_bytes, expected_sdu_len);
       exit(-1);
     }
+
+    // check content
+    uint8_t first_byte = *sdu->msg;
+    for (uint32_t i = 0; i < sdu->N_bytes; i++) {
+      if (sdu->msg[i] != first_byte) {
+        printf("Received corrupted SDU with size %d. Exiting.\n", sdu->N_bytes);
+        srslte_vec_fprint_byte(stdout, sdu->msg, sdu->N_bytes);
+        exit(-1);
+      }
+    }
+
+    // srslte_vec_fprint_byte(stdout, sdu->msg, sdu->N_bytes);
     sdus.push_back(std::move(sdu));
   }
   void write_pdu_bcch_bch(unique_byte_buffer_t sdu) {}

lib/test/upper/rlc_um_data_test.cc

@@ -19,9 +19,9 @@
  *
  */
 
-#include <iostream>
+#include "srslte/upper/rlc_um_lte.h"
-#include "srslte/upper/rlc_um.h"
 #include <assert.h>
+#include <iostream>
 
 // Fixed header only
 uint8_t pdu1[] = {0x18 ,0xE2};

lib/test/upper/rlc_um_nr_pdu_test.cc

@@ -21,7 +21,7 @@
 
 #include "srslte/config.h"
 #include "srslte/upper/rlc.h"
-#include "srslte/upper/rlc_um.h"
+#include "srslte/upper/rlc_um_nr.h"
 
 #include <array>
 #include <iostream>
@@ -53,7 +53,7 @@ int write_pdu_to_pcap(const uint32_t lcid, const uint8_t* payload, const uint32_
 #if PCAP
   if (pcap_handle) {
     byte_buffer_t      tx_buffer;
-    srslte::mac_nr_pdu tx_pdu;
+    srslte::mac_nr_sch_pdu tx_pdu;
     tx_pdu.init_tx(&tx_buffer, len + 10);
     tx_pdu.add_sdu(lcid, payload, len);
     tx_pdu.pack();

lib/test/upper/rlc_um_nr_test.cc

@@ -23,7 +23,7 @@
 #include "srslte/common/log_filter.h"
 #include "srslte/config.h"
 #include "srslte/upper/rlc.h"
-#include "srslte/upper/rlc_um.h"
+#include "srslte/upper/rlc_um_nr.h"
 
 #include <array>
 #include <iostream>
@@ -55,7 +55,7 @@ int write_pdu_to_pcap(const uint32_t lcid, const uint8_t* payload, const uint32_
 #if PCAP
   if (pcap_handle) {
     byte_buffer_t          tx_buffer;
-    srslte::nr_mac_pdu tx_pdu;
+    srslte::mac_nr_sch_pdu tx_pdu;
     tx_pdu.init_tx(&tx_buffer, len + 10);
     tx_pdu.add_sdu(lcid, payload, len);
     tx_pdu.pack();
@@ -76,29 +76,47 @@ srslte::byte_buffer_t make_pdu_and_log(const std::array<uint8_t, N>& tv)
   return pdu;
 }
 
-// Basic test to write UM PDU with 6 bit SN
+// Helper class to create two pre-configured RLC instances
-int rlc_um_nr_test1()
+class rlc_um_nr_test_context1
+{
+public:
+  rlc_um_nr_test_context1() :
+    log1("RLC_UM_1"),
+    log2("RLC_UM_2"),
+    timers(16),
+    rlc1(&log1, 3, &tester, &tester, &timers),
+    rlc2(&log2, 3, &tester, &tester, &timers)
   {
-  srslte::log_filter log1("RLC_UM_1");
+    // setup logging
-  srslte::log_filter log2("RLC_UM_2");
     log1.set_level(srslte::LOG_LEVEL_DEBUG);
     log2.set_level(srslte::LOG_LEVEL_DEBUG);
     log1.set_hex_limit(-1);
     log2.set_hex_limit(-1);
-  rlc_um_tester         tester;
-  srslte::timer_handler timers(16);
-  const uint32_t        num_sdus = 5;
-  int                   len      = 0;
-
-  rlc_um rlc1(&log1, 3, &tester, &tester, &timers);
-  rlc_um rlc2(&log2, 3, &tester, &tester, &timers);
 
+    // configure RLC entities
     rlc_config_t cnfg = rlc_config_t::default_rlc_um_nr_config(6);
-
+    if (rlc1.configure(cnfg) != true) {
-  TESTASSERT(rlc1.configure(cnfg) == true);
+      fprintf(stderr, "Couldn't configure RLC1 object\n");
-  TESTASSERT(rlc2.configure(cnfg) == true);
+    }
+    if (rlc2.configure(cnfg) != true) {
+      fprintf(stderr, "Couldn't configure RLC2 object\n");
+    }
 
     tester.set_expected_sdu_len(1);
+  }
+
+  srslte::log_filter    log1, log2;
+  srslte::timer_handler timers;
+  rlc_um_tester         tester;
+  rlc_um_nr             rlc1, rlc2;
+};
+
+// Basic test to write UM PDU with 6 bit SN (full SDUs are transmitted in each PDU)
+int rlc_um_nr_test1()
+{
+  rlc_um_nr_test_context1 ctxt;
+
+  const uint32_t num_sdus = 5, num_pdus = 5;
 
   // Push 5 SDUs into RLC1
   byte_buffer_pool*    pool = byte_buffer_pool::get_instance();
@@ -107,53 +125,117 @@ int rlc_um_nr_test1()
     sdu_bufs[i]          = srslte::allocate_unique_buffer(*pool, true);
     *sdu_bufs[i]->msg    = i; // Write the index into the buffer
     sdu_bufs[i]->N_bytes = 1; // Give each buffer a size of 1 byte
-    rlc1.write_sdu(std::move(sdu_bufs[i]));
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
   }
 
-  TESTASSERT(14 == rlc1.get_buffer_state());
+  TESTASSERT(14 == ctxt.rlc1.get_buffer_state());
 
   // Read 5 PDUs from RLC1 (1 byte each)
-  unique_byte_buffer_t pdu_bufs[num_sdus];
+  unique_byte_buffer_t pdu_bufs[num_pdus];
-  for (uint32_t i = 0; i < num_sdus; i++) {
+  for (uint32_t i = 0; i < num_pdus; i++) {
     pdu_bufs[i]          = srslte::allocate_unique_buffer(*pool, true);
-    len                  = rlc1.read_pdu(pdu_bufs[i]->msg, 4); // 3 bytes for header + payload
+    int len              = ctxt.rlc1.read_pdu(pdu_bufs[i]->msg, 4); // 3 bytes for header + payload
     pdu_bufs[i]->N_bytes = len;
 
     // write PCAP
     write_pdu_to_pcap(4, pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
   }
 
-  TESTASSERT(0 == rlc1.get_buffer_state());
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
 
-  // TODO: add receive test
+  // Write 5 PDUs into RLC2
+  for (uint32_t i = 0; i < num_pdus; i++) {
+    ctxt.rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+  }
+
+  TESTASSERT(0 == ctxt.rlc2.get_buffer_state());
+
+  TESTASSERT(num_sdus == ctxt.tester.get_num_sdus());
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); i++) {
+    TESTASSERT(ctxt.tester.sdus.at(i)->N_bytes == 1);
+    TESTASSERT(*(ctxt.tester.sdus[i]->msg) == i);
+  }
 
   return SRSLTE_SUCCESS;
 }
 
 // Basic test for SDU segmentation
-int rlc_um_nr_test2()
+int rlc_um_nr_test2(bool reverse_rx = false)
 {
-  srslte::log_filter log1("RLC_UM_1");
+  rlc_um_nr_test_context1 ctxt;
-  srslte::log_filter log2("RLC_UM_2");
+
-  log1.set_level(srslte::LOG_LEVEL_DEBUG);
-  log2.set_level(srslte::LOG_LEVEL_DEBUG);
-  log1.set_hex_limit(-1);
-  log2.set_hex_limit(-1);
-  rlc_um_tester         tester;
-  srslte::timer_handler timers(16);
   const uint32_t num_sdus = 1;
   const uint32_t sdu_size = 100;
-  int                   len      = 0;
 
-  rlc_um rlc1(&log1, 3, &tester, &tester, &timers);
+  ctxt.tester.set_expected_sdu_len(sdu_size);
-  rlc_um rlc2(&log2, 3, &tester, &tester, &timers);
 
-  rlc_config_t cnfg = rlc_config_t::default_rlc_um_nr_config(6);
+  // Push SDUs into RLC1
+  byte_buffer_pool*    pool = byte_buffer_pool::get_instance();
+  unique_byte_buffer_t sdu_bufs[num_sdus];
+  for (uint32_t i = 0; i < num_sdus; i++) {
+    sdu_bufs[i] = srslte::allocate_unique_buffer(*pool, true);
+    // Write the index into the buffer
+    for (uint32_t k = 0; k < sdu_size; ++k) {
+      sdu_bufs[i]->msg[k] = i;
+    }
+    sdu_bufs[i]->N_bytes = sdu_size;
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
+  }
 
-  TESTASSERT(rlc1.configure(cnfg) == true);
+  // FIXME: check buffer state calculation
-  TESTASSERT(rlc2.configure(cnfg) == true);
+  TESTASSERT(103 == ctxt.rlc1.get_buffer_state());
 
-  tester.set_expected_sdu_len(1);
+  // Read PDUs from RLC1 with grant of 25 Bytes each
+  const uint32_t       max_num_pdus = 10;
+  uint32               num_pdus     = 0;
+  unique_byte_buffer_t pdu_bufs[max_num_pdus];
+
+  while (ctxt.rlc1.get_buffer_state() != 0 && num_pdus < max_num_pdus) {
+    pdu_bufs[num_pdus]          = srslte::allocate_unique_buffer(*pool, true);
+    int len                     = ctxt.rlc1.read_pdu(pdu_bufs[num_pdus]->msg, 25); // 3 bytes for header + payload
+    pdu_bufs[num_pdus]->N_bytes = len;
+
+    // write PCAP
+    write_pdu_to_pcap(4, pdu_bufs[num_pdus]->msg, pdu_bufs[num_pdus]->N_bytes);
+
+    num_pdus++;
+  }
+
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
+
+  // Write PDUs into RLC2
+  if (reverse_rx) {
+    // receive PDUs in reverse order
+    for (uint32_t i = num_pdus; i > 0; i--) {
+      ctxt.rlc2.write_pdu(pdu_bufs[i - 1]->msg, pdu_bufs[i - 1]->N_bytes);
+    }
+  } else {
+    // receive PDUs in order
+    for (uint32_t i = 0; i < num_pdus; i++) {
+      ctxt.rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+    }
+  }
+
+  TESTASSERT(0 == ctxt.rlc2.get_buffer_state());
+
+  TESTASSERT(num_sdus == ctxt.tester.get_num_sdus());
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); i++) {
+    TESTASSERT(ctxt.tester.sdus.at(i)->N_bytes == sdu_size);
+    TESTASSERT(*(ctxt.tester.sdus[i]->msg) == i);
+  }
+
+  return SRSLTE_SUCCESS;
+}
+
+// Test reception of segmented RLC PDUs (two different SDUs with same PDU segmentation)
+int rlc_um_nr_test4()
+{
+  rlc_um_nr_test_context1 ctxt;
+
+  const uint32_t num_sdus = 2;
+  const uint32_t sdu_size = 100;
+
+  ctxt.tester.set_expected_sdu_len(sdu_size);
 
   // Push SDUs into RLC1
   byte_buffer_pool*    pool = byte_buffer_pool::get_instance();
@@ -165,27 +247,318 @@ int rlc_um_nr_test2()
       sdu_bufs[i]->msg[k] = i;
     }
     sdu_bufs[i]->N_bytes = sdu_size;
-    rlc1.write_sdu(std::move(sdu_bufs[i]));
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
   }
 
   // FIXME: check buffer state calculation
-  TESTASSERT(103 == rlc1.get_buffer_state());
+  int bsr = ctxt.rlc1.get_buffer_state();
+  TESTASSERT(bsr == 205);
+
+  // Read PDUs from RLC1 with grant of 25 Bytes each
+  const uint32_t       max_num_pdus = 20;
+  uint32               num_pdus     = 0;
+  unique_byte_buffer_t pdu_bufs[max_num_pdus];
+
+  while (ctxt.rlc1.get_buffer_state() != 0 && num_pdus < max_num_pdus) {
+    pdu_bufs[num_pdus]          = srslte::allocate_unique_buffer(*pool, true);
+    int len                     = ctxt.rlc1.read_pdu(pdu_bufs[num_pdus]->msg, 25); // 3 bytes for header + payload
+    pdu_bufs[num_pdus]->N_bytes = len;
+    num_pdus++;
+  }
+
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
+
+  // Write PDUs into RLC2 (except 1 and 6
+  for (uint32_t i = 0; i < num_pdus; i++) {
+    if (i != 1 && i != 6) {
+      ctxt.rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+      write_pdu_to_pcap(4, pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+    }
+  }
+
+  // write remaining two PDUs in reverse-order (so SN=1 is received first)
+  ctxt.rlc2.write_pdu(pdu_bufs[6]->msg, pdu_bufs[6]->N_bytes);
+  write_pdu_to_pcap(4, pdu_bufs[6]->msg, pdu_bufs[6]->N_bytes);
+
+  ctxt.rlc2.write_pdu(pdu_bufs[1]->msg, pdu_bufs[1]->N_bytes);
+  write_pdu_to_pcap(4, pdu_bufs[1]->msg, pdu_bufs[1]->N_bytes);
+
+  TESTASSERT(0 == ctxt.rlc2.get_buffer_state());
+
+  TESTASSERT(num_sdus == ctxt.tester.get_num_sdus());
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); i++) {
+    TESTASSERT(ctxt.tester.sdus.at(i)->N_bytes == sdu_size);
+
+    // common tester makes sure the all bytes within the SDU are the same, but it doesn't verify the SDUs are the ones
+    // transmitted, so check this here
+    if (i == 0) {
+      // first SDU is SN=1
+      TESTASSERT(*(ctxt.tester.sdus.at(i)->msg) == 0x01);
+    } else {
+      // second SDU is SN=0
+      TESTASSERT(*(ctxt.tester.sdus.at(i)->msg) == 0x00);
+    }
+  }
+
+  return SRSLTE_SUCCESS;
+}
+
+// Handling of re-transmitted segments (e.g. after PHY retransmission)
+int rlc_um_nr_test5(const uint32_t last_sn)
+{
+  rlc_um_nr_test_context1 ctxt;
+
+  const uint32_t num_sdus = 1;
+  const uint32_t sdu_size = 100;
+
+  ctxt.tester.set_expected_sdu_len(sdu_size);
+
+  // Push SDUs into RLC1
+  byte_buffer_pool*    pool = byte_buffer_pool::get_instance();
+  unique_byte_buffer_t sdu_bufs[num_sdus];
+  for (uint32_t i = 0; i < num_sdus; i++) {
+    sdu_bufs[i] = srslte::allocate_unique_buffer(*pool, true);
+    // Write the index into the buffer
+    for (uint32_t k = 0; k < sdu_size; ++k) {
+      sdu_bufs[i]->msg[k] = i;
+    }
+    sdu_bufs[i]->N_bytes = sdu_size;
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
+  }
+
+  // FIXME: check buffer state calculation
+  TESTASSERT(103 == ctxt.rlc1.get_buffer_state());
 
   // Read PDUs from RLC1 with grant of 25 Bytes each
   const uint32_t       max_num_pdus = 10;
+  uint32               num_pdus     = 0;
   unique_byte_buffer_t pdu_bufs[max_num_pdus];
-  for (uint32_t i = 0; i < max_num_pdus; i++) {
+
-    pdu_bufs[i]          = srslte::allocate_unique_buffer(*pool, true);
+  while (ctxt.rlc1.get_buffer_state() != 0 && num_pdus < max_num_pdus) {
-    len                  = rlc1.read_pdu(pdu_bufs[i]->msg, 25); // 3 bytes for header + payload
+    pdu_bufs[num_pdus]          = srslte::allocate_unique_buffer(*pool, true);
-    pdu_bufs[i]->N_bytes = len;
+    int len                     = ctxt.rlc1.read_pdu(pdu_bufs[num_pdus]->msg, 25); // 3 bytes for header + payload
+    pdu_bufs[num_pdus]->N_bytes = len;
 
     // write PCAP
-    write_pdu_to_pcap(4, pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+    write_pdu_to_pcap(4, pdu_bufs[num_pdus]->msg, pdu_bufs[num_pdus]->N_bytes);
+
+    num_pdus++;
+  }
+
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
+
+  // Write alls PDUs twice into RLC2 (except third)
+  for (uint32_t k = 0; k < 2; k++) {
+    for (uint32_t i = 0; i < num_pdus; i++) {
+      if (i != last_sn) {
+        ctxt.rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+      }
+    }
   }
 
-  TESTASSERT(0 == rlc1.get_buffer_state());
+  // Write third PDU
+  ctxt.rlc2.write_pdu(pdu_bufs[last_sn]->msg, pdu_bufs[last_sn]->N_bytes);
 
-  // TODO: add receive test
+  TESTASSERT(0 == ctxt.rlc2.get_buffer_state());
+
+  TESTASSERT(num_sdus == ctxt.tester.get_num_sdus());
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); i++) {
+    TESTASSERT(ctxt.tester.sdus.at(i)->N_bytes == sdu_size);
+    TESTASSERT(*(ctxt.tester.sdus[i]->msg) == i);
+  }
+
+  return SRSLTE_SUCCESS;
+}
+
+// Test of wrap-around of reassembly window
+int rlc_um_nr_test6()
+{
+  rlc_um_nr_test_context1 ctxt;
+
+  const uint32_t num_sdus = 64;
+  const uint32_t sdu_size = 10;
+
+  ctxt.tester.set_expected_sdu_len(sdu_size);
+
+  // Push SDUs into RLC1
+  byte_buffer_pool*    pool = byte_buffer_pool::get_instance();
+  unique_byte_buffer_t sdu_bufs[num_sdus];
+  for (uint32_t i = 0; i < num_sdus; i++) {
+    sdu_bufs[i] = srslte::allocate_unique_buffer(*pool, true);
+    // Write the index into the buffer
+    for (uint32_t k = 0; k < sdu_size; ++k) {
+      sdu_bufs[i]->msg[k] = i;
+    }
+    sdu_bufs[i]->N_bytes = sdu_size;
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
+  }
+
+  // FIXME: check buffer state calculation
+  // TESTASSERT(103 == ctxt.rlc1.get_buffer_state());
+
+  // Read PDUs from RLC1 with grant of 8 Bytes each
+  const uint32_t       max_num_pdus = num_sdus * 2; // we need 2 PDUs for each SDU
+  uint32               num_pdus     = 0;
+  unique_byte_buffer_t pdu_bufs[max_num_pdus];
+
+  while (ctxt.rlc1.get_buffer_state() != 0 && num_pdus < max_num_pdus) {
+    pdu_bufs[num_pdus]          = srslte::allocate_unique_buffer(*pool, true);
+    int len                     = ctxt.rlc1.read_pdu(pdu_bufs[num_pdus]->msg, 8); // 3 bytes for header + payload
+    pdu_bufs[num_pdus]->N_bytes = len;
+
+    // write PCAP
+    write_pdu_to_pcap(4, pdu_bufs[num_pdus]->msg, pdu_bufs[num_pdus]->N_bytes);
+
+    num_pdus++;
+  }
+
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
+
+  // Write PDUs into RLC2
+  for (uint32_t i = 0; i < num_pdus; i++) {
+    ctxt.rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+  }
+
+  TESTASSERT(0 == ctxt.rlc2.get_buffer_state());
+
+  TESTASSERT(num_sdus == ctxt.tester.get_num_sdus());
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); i++) {
+    TESTASSERT(ctxt.tester.sdus.at(i)->N_bytes == sdu_size);
+    TESTASSERT(*(ctxt.tester.sdus[i]->msg) == i);
+  }
+
+  return SRSLTE_SUCCESS;
+}
+
+// Segment loss received too many new PDUs (lost PDU outside of reassembly window)
+int rlc_um_nr_test7()
+{
+  rlc_um_nr_test_context1 ctxt;
+
+  const uint32_t num_sdus = 64;
+  const uint32_t sdu_size = 10;
+
+  ctxt.tester.set_expected_sdu_len(sdu_size);
+
+  // Push SDUs into RLC1
+  byte_buffer_pool*    pool = byte_buffer_pool::get_instance();
+  unique_byte_buffer_t sdu_bufs[num_sdus];
+  for (uint32_t i = 0; i < num_sdus; i++) {
+    sdu_bufs[i] = srslte::allocate_unique_buffer(*pool, true);
+    // Write the index into the buffer
+    for (uint32_t k = 0; k < sdu_size; ++k) {
+      sdu_bufs[i]->msg[k] = i;
+    }
+    sdu_bufs[i]->N_bytes = sdu_size;
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
+  }
+
+  // FIXME: check buffer state calculation
+  // TESTASSERT(103 == ctxt.rlc1.get_buffer_state());
+
+  // Read PDUs from RLC1 with grant of 8 Bytes each
+  const uint32_t       max_num_pdus = num_sdus * 2; // we need 2 PDUs for each SDU
+  uint32               num_pdus     = 0;
+  unique_byte_buffer_t pdu_bufs[max_num_pdus];
+
+  while (ctxt.rlc1.get_buffer_state() != 0 && num_pdus < max_num_pdus) {
+    pdu_bufs[num_pdus]          = srslte::allocate_unique_buffer(*pool, true);
+    int len                     = ctxt.rlc1.read_pdu(pdu_bufs[num_pdus]->msg, 8); // 3 bytes for header + payload
+    pdu_bufs[num_pdus]->N_bytes = len;
+
+    // write PCAP
+    write_pdu_to_pcap(4, pdu_bufs[num_pdus]->msg, pdu_bufs[num_pdus]->N_bytes);
+
+    num_pdus++;
+  }
+
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
+
+  // Write PDUs into RLC2 (except 11th)
+  for (uint32_t i = 0; i < num_pdus; i++) {
+    if (i != 10) {
+      ctxt.rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+    }
+  }
+
+  TESTASSERT(0 == ctxt.rlc2.get_buffer_state());
+
+  TESTASSERT(num_sdus - 1 == ctxt.tester.get_num_sdus());
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); i++) {
+    TESTASSERT(ctxt.tester.sdus.at(i)->N_bytes == sdu_size);
+  }
+
+  rlc_bearer_metrics_t rlc2_metrics = ctxt.rlc2.get_metrics();
+  TESTASSERT(rlc2_metrics.num_lost_pdus == 1);
+
+  return SRSLTE_SUCCESS;
+}
+
+// Segment loss and expiry of reassembly timer
+int rlc_um_nr_test8()
+{
+  rlc_um_nr_test_context1 ctxt;
+
+  const uint32_t num_sdus = 10;
+  const uint32_t sdu_size = 10;
+
+  ctxt.tester.set_expected_sdu_len(sdu_size);
+
+  // Push SDUs into RLC1
+  byte_buffer_pool*    pool = byte_buffer_pool::get_instance();
+  unique_byte_buffer_t sdu_bufs[num_sdus];
+  for (uint32_t i = 0; i < num_sdus; i++) {
+    sdu_bufs[i] = srslte::allocate_unique_buffer(*pool, true);
+    // Write the index into the buffer
+    for (uint32_t k = 0; k < sdu_size; ++k) {
+      sdu_bufs[i]->msg[k] = i;
+    }
+    sdu_bufs[i]->N_bytes = sdu_size;
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
+  }
+
+  // FIXME: check buffer state calculation
+  // TESTASSERT(103 == ctxt.rlc1.get_buffer_state());
+
+  // Read PDUs from RLC1 with grant of 8 Bytes each
+  const uint32_t       max_num_pdus = 20 * 2; // we need 2 PDUs for each SDU
+  uint32               num_pdus     = 0;
+  unique_byte_buffer_t pdu_bufs[max_num_pdus];
+
+  while (ctxt.rlc1.get_buffer_state() != 0 && num_pdus < max_num_pdus) {
+    pdu_bufs[num_pdus]          = srslte::allocate_unique_buffer(*pool, true);
+    int len                     = ctxt.rlc1.read_pdu(pdu_bufs[num_pdus]->msg, 8); // 3 bytes for header + payload
+    pdu_bufs[num_pdus]->N_bytes = len;
+
+    // write PCAP
+    write_pdu_to_pcap(4, pdu_bufs[num_pdus]->msg, pdu_bufs[num_pdus]->N_bytes);
+
+    num_pdus++;
+  }
+
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
+
+  // Write PDUs into RLC2 (except 2nd)
+  for (uint32_t i = 0; i < num_pdus; i++) {
+    if (i != 2) {
+      ctxt.rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+    }
+  }
+
+  TESTASSERT(0 == ctxt.rlc2.get_buffer_state());
+
+  // let t-reassembly expire
+  while (ctxt.timers.nof_running_timers() != 0) {
+    ctxt.timers.step_all();
+  }
+
+  TESTASSERT(num_sdus - 1 == ctxt.tester.get_num_sdus());
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); i++) {
+    TESTASSERT(ctxt.tester.sdus.at(i)->N_bytes == sdu_size);
+  }
+
+  rlc_bearer_metrics_t rlc2_metrics = ctxt.rlc2.get_metrics();
+  TESTASSERT(rlc2_metrics.num_lost_pdus == 1);
 
   return SRSLTE_SUCCESS;
 }
@@ -206,5 +579,39 @@ int main(int argc, char** argv)
     fprintf(stderr, "rlc_um_nr_test2() failed.\n");
     return SRSLTE_ERROR;
   }
+
+  // same like above but PDUs delivered in reverse order
+  if (rlc_um_nr_test2(true)) {
+    fprintf(stderr, "rlc_um_nr_test2(true) failed.\n");
+    return SRSLTE_ERROR;
+  }
+
+  if (rlc_um_nr_test4()) {
+    fprintf(stderr, "rlc_um_nr_test4() failed.\n");
+    return SRSLTE_ERROR;
+  }
+
+  for (uint32_t i = 0; i < 5; ++i) {
+    if (rlc_um_nr_test5(i)) {
+      fprintf(stderr, "rlc_um_nr_test5() for i=%d failed.\n", i);
+      return SRSLTE_ERROR;
+    }
+  }
+
+  if (rlc_um_nr_test6()) {
+    fprintf(stderr, "rlc_um_nr_test6() failed.\n");
+    return SRSLTE_ERROR;
+  }
+
+  if (rlc_um_nr_test7()) {
+    fprintf(stderr, "rlc_um_nr_test7() failed.\n");
+    return SRSLTE_ERROR;
+  }
+
+  if (rlc_um_nr_test8()) {
+    fprintf(stderr, "rlc_um_nr_test8() failed.\n");
+    return SRSLTE_ERROR;
+  }
+
   return SRSLTE_SUCCESS;
 }

lib/test/upper/rlc_um_test.cc

@@ -21,7 +21,7 @@
 
 #include "rlc_test_common.h"
 #include "srslte/common/log_filter.h"
-#include "srslte/upper/rlc_um.h"
+#include "srslte/upper/rlc_um_lte.h"
 #include <iostream>
 
 #define TESTASSERT(cond)                                                                                               \
@@ -39,34 +39,44 @@ using namespace srslte;
 using namespace srsue;
 using namespace asn1::rrc;
 
-int basic_test()
+// Helper class to create two pre-configured RLC instances
+class rlc_um_lte_test_context1
+{
+public:
+  rlc_um_lte_test_context1() :
+    log1("RLC_UM_1"),
+    log2("RLC_UM_2"),
+    timers(16),
+    rlc1(&log1, 3, &tester, &tester, &timers),
+    rlc2(&log2, 3, &tester, &tester, &timers)
   {
-  srslte::log_filter log1("RLC_UM_1");
+    // setup logging
-  srslte::log_filter log2("RLC_UM_2");
     log1.set_level(srslte::LOG_LEVEL_DEBUG);
     log2.set_level(srslte::LOG_LEVEL_DEBUG);
     log1.set_hex_limit(-1);
     log2.set_hex_limit(-1);
-  rlc_um_tester         tester;
-  srslte::timer_handler timers(16);
-  int                   len = 0;
-
-  rlc_um rlc1(&log1, 3, &tester, &tester, &timers);
-  rlc_um rlc2(&log2, 3, &tester, &tester, &timers);
 
+    // configure RLC entities
     rlc_config_t cnfg = rlc_config_t::default_rlc_um_config(10);
-  cnfg.rlc_mode              = rlc_mode_t::um;
+    if (rlc1.configure(cnfg) != true) {
-  cnfg.um.t_reordering       = 5;
+      fprintf(stderr, "Couldn't configure RLC1 object\n");
-  cnfg.um.rx_sn_field_length = rlc_umd_sn_size_t::size10bits;
+    }
-  cnfg.um.rx_window_size     = 512;
+    if (rlc2.configure(cnfg) != true) {
-  cnfg.um.rx_mod             = 1024;
+      fprintf(stderr, "Couldn't configure RLC2 object\n");
-  cnfg.um.tx_sn_field_length = rlc_umd_sn_size_t::size10bits;
+    }
-  cnfg.um.tx_mod             = 1024;
-
-  TESTASSERT(rlc1.configure(cnfg) == true);
-  TESTASSERT(rlc2.configure(cnfg) == true);
 
     tester.set_expected_sdu_len(1);
+  }
+
+  srslte::log_filter log1, log2;
+  srslte::timer_handler    timers;
+  rlc_um_tester       tester;
+  rlc_um_lte          rlc1, rlc2;
+};
+
+int basic_test()
+{
+  rlc_um_lte_test_context1 ctxt;
 
   // Push 5 SDUs into RLC1
   byte_buffer_pool*  pool = byte_buffer_pool::get_instance();
@@ -76,33 +86,31 @@ int basic_test()
     sdu_bufs[i]          = srslte::allocate_unique_buffer(*pool, true);
     *sdu_bufs[i]->msg    = i; // Write the index into the buffer
     sdu_bufs[i]->N_bytes = 1; // Give each buffer a size of 1 byte
-    rlc1.write_sdu(std::move(sdu_bufs[i]));
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
   }
 
-  TESTASSERT(14 == rlc1.get_buffer_state());
+  TESTASSERT(14 == ctxt.rlc1.get_buffer_state());
 
   // Read 5 PDUs from RLC1 (1 byte each)
   byte_buffer_t pdu_bufs[NBUFS];
-  for(int i=0;i<NBUFS;i++)
+  for (int i = 0; i < NBUFS; i++) {
-  {
+    int len             = ctxt.rlc1.read_pdu(pdu_bufs[i].msg, 4); // 3 bytes for header + payload
-    len = rlc1.read_pdu(pdu_bufs[i].msg, 4); // 3 bytes for header + payload
     pdu_bufs[i].N_bytes = len;
   }
 
-  TESTASSERT(0 == rlc1.get_buffer_state());
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
 
   // Write 5 PDUs into RLC2
-  for(int i=0;i<NBUFS;i++)
+  for (int i = 0; i < NBUFS; i++) {
-  {
+    ctxt.rlc2.write_pdu(pdu_bufs[i].msg, pdu_bufs[i].N_bytes);
-    rlc2.write_pdu(pdu_bufs[i].msg, pdu_bufs[i].N_bytes);
   }
 
-  TESTASSERT(0 == rlc2.get_buffer_state());
+  TESTASSERT(0 == ctxt.rlc2.get_buffer_state());
 
-  TESTASSERT(NBUFS == tester.get_num_sdus());
+  TESTASSERT(NBUFS == ctxt.tester.get_num_sdus());
-  for (uint32_t i = 0; i < tester.sdus.size(); i++) {
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); i++) {
-    TESTASSERT(tester.sdus.at(i)->N_bytes == 1);
+    TESTASSERT(ctxt.tester.sdus.at(i)->N_bytes == 1);
-    TESTASSERT(*(tester.sdus[i]->msg) == i);
+    TESTASSERT(*(ctxt.tester.sdus[i]->msg) == i);
   }
 
   return 0;
@@ -110,87 +118,53 @@ int basic_test()
 
 int loss_test()
 {
-  srslte::log_filter log1("RLC_UM_1");
+  rlc_um_lte_test_context1 ctxt;
-  srslte::log_filter log2("RLC_UM_2");
-  log1.set_level(srslte::LOG_LEVEL_DEBUG);
-  log2.set_level(srslte::LOG_LEVEL_DEBUG);
-  log1.set_hex_limit(-1);
-  log2.set_hex_limit(-1);
-  rlc_um_tester         tester;
-  srslte::timer_handler timers(16);
-  int                   len = 0;
-
-  rlc_um rlc1(&log1, 3, &tester, &tester, &timers);
-  rlc_um rlc2(&log2, 3, &tester, &tester, &timers);
-
-  rlc_config_t cnfg = rlc_config_t::default_rlc_um_config(10);
-
-  rlc1.configure(cnfg);
-  rlc2.configure(cnfg);
-
-  tester.set_expected_sdu_len(1);
 
   // Push 5 SDUs into RLC1
   byte_buffer_pool*  pool = byte_buffer_pool::get_instance();
   unique_byte_buffer_t sdu_bufs[NBUFS];
-  for(int i=0;i<NBUFS;i++)
+  for (int i = 0; i < NBUFS; i++) {
-  {
     sdu_bufs[i]          = srslte::allocate_unique_buffer(*pool, true);
     sdu_bufs[i]->msg[0]  = i; // Write the index into the buffer
     sdu_bufs[i]->N_bytes = 1; // Give each buffer a size of 1 byte
-    rlc1.write_sdu(std::move(sdu_bufs[i]));
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
   }
 
-  TESTASSERT(14 == rlc1.get_buffer_state());
+  TESTASSERT(14 == ctxt.rlc1.get_buffer_state());
 
   // Read 5 PDUs from RLC1 (1 byte each)
   byte_buffer_t pdu_bufs[NBUFS];
-  for(int i=0;i<NBUFS;i++)
+  for (int i = 0; i < NBUFS; i++) {
-  {
+    int len             = ctxt.rlc1.read_pdu(pdu_bufs[i].msg, 4); // 3 bytes for header + payload
-    len = rlc1.read_pdu(pdu_bufs[i].msg, 4); // 3 bytes for header + payload
     pdu_bufs[i].N_bytes = len;
   }
 
-  TESTASSERT(0 == rlc1.get_buffer_state());
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
 
   // Write 5 PDUs into RLC2 (skip SN 1)
-  for(int i=0;i<NBUFS;i++)
+  for (int i = 0; i < NBUFS; i++) {
-  {
+    if (i != 1) {
-    if(i != 1)
+      ctxt.rlc2.write_pdu(pdu_bufs[i].msg, pdu_bufs[i].N_bytes);
-      rlc2.write_pdu(pdu_bufs[i].msg, pdu_bufs[i].N_bytes);
+    }
   }
 
   // Step the reordering timer until expiry
-  //  while (!timers.get(1)->is_expired())
+  while (ctxt.timers.nof_running_timers() != 0) {
-  //    timers.get(1)->step();
+    ctxt.timers.step_all();
-  while (timers.nof_running_timers() != 0) {
-    timers.step_all();
   }
 
-  TESTASSERT(NBUFS - 1 == tester.sdus.size());
+  TESTASSERT(NBUFS - 1 == ctxt.tester.sdus.size());
 
   return 0;
 }
 
 int basic_mbsfn_test()
 {
-  srslte::log_filter log1("RLC_UM_1");
+  rlc_um_lte_test_context1 ctxt;
-  srslte::log_filter log2("RLC_UM_2");
-  log1.set_level(srslte::LOG_LEVEL_DEBUG);
-  log2.set_level(srslte::LOG_LEVEL_DEBUG);
-  log1.set_hex_limit(-1);
-  log2.set_hex_limit(-1);
-  rlc_um_tester         tester;
-  srslte::timer_handler timers(16);
-  int                   len = 0;
 
-  rlc_um rlc1(&log1, 3, &tester, &tester, &timers);
+  // configure as MCH
-  rlc_um rlc2(&log2, 3, &tester, &tester, &timers);
+  ctxt.rlc1.configure(rlc_config_t::mch_config());
-
+  ctxt.rlc2.configure(rlc_config_t::mch_config());
-  rlc1.configure(rlc_config_t::mch_config());
-  rlc2.configure(rlc_config_t::mch_config());
-
-  tester.set_expected_sdu_len(1);
 
   // Push 5 SDUs into RLC1
   byte_buffer_pool*  pool = byte_buffer_pool::get_instance();
@@ -200,33 +174,32 @@ int basic_mbsfn_test()
     sdu_bufs[i]          = srslte::allocate_unique_buffer(*pool, true);
     sdu_bufs[i]->msg[0]  = i; // Write the index into the buffer
     sdu_bufs[i]->N_bytes = 1; // Give each buffer a size of 1 byte
-    rlc1.write_sdu(std::move(sdu_bufs[i]));
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
   }
 
-  TESTASSERT(13 == rlc1.get_buffer_state());
+  TESTASSERT(13 == ctxt.rlc1.get_buffer_state());
 
   // Read 5 PDUs from RLC1 (1 byte each)
   byte_buffer_t pdu_bufs[NBUFS*2];
   for(int i=0;i<NBUFS;i++)
   {
-    len = rlc1.read_pdu(pdu_bufs[i].msg, 3); // 2 bytes for header + payload
+    int len             = ctxt.rlc1.read_pdu(pdu_bufs[i].msg, 3); // 2 bytes for header + payload
     pdu_bufs[i].N_bytes = len;
   }
 
-  TESTASSERT(0 == rlc1.get_buffer_state());
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
 
   // Write 5 PDUs into RLC2
-  for(int i=0;i<NBUFS;i++)
+  for (int i = 0; i < NBUFS; i++) {
-  {
+    ctxt.rlc2.write_pdu(pdu_bufs[i].msg, pdu_bufs[i].N_bytes);
-    rlc2.write_pdu(pdu_bufs[i].msg, pdu_bufs[i].N_bytes);
   }
 
-  TESTASSERT(0 == rlc2.get_buffer_state());
+  TESTASSERT(0 == ctxt.rlc2.get_buffer_state());
 
-  TESTASSERT(NBUFS == tester.sdus.size());
+  TESTASSERT(NBUFS == ctxt.tester.sdus.size());
-  for (uint32_t i = 0; i < tester.sdus.size(); i++) {
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); i++) {
-    TESTASSERT(tester.sdus[i]->N_bytes == 1);
+    TESTASSERT(ctxt.tester.sdus[i]->N_bytes == 1);
-    TESTASSERT(*(tester.sdus[i]->msg) == i);
+    TESTASSERT(*(ctxt.tester.sdus[i]->msg) == i);
   }
 
   return 0;
@@ -245,30 +218,18 @@ int basic_mbsfn_test()
 // PDUs than rx_mod are received.
 int reassmble_test()
 {
-  srslte::log_filter log1("RLC_UM_1");
+  rlc_um_lte_test_context1 ctxt;
-  srslte::log_filter log2("RLC_UM_2");
-  log1.set_level(srslte::LOG_LEVEL_DEBUG);
-  log2.set_level(srslte::LOG_LEVEL_DEBUG);
-  log1.set_hex_limit(-1);
-  log2.set_hex_limit(-1);
-  rlc_um_tester         tester;
-  srslte::timer_handler timers(16);
-  int                   len = 0;
-
-  rlc_um rlc1(&log1, 3, &tester, &tester, &timers);
-  rlc_um rlc2(&log2, 3, &tester, &tester, &timers);
 
+  // reconfigure them with 5bit SNs
   rlc_config_t cnfg = rlc_config_t::default_rlc_um_config(5);
-
+  ctxt.rlc1.configure(cnfg);
-  rlc1.configure(cnfg);
+  ctxt.rlc2.configure(cnfg);
-  rlc2.configure(cnfg);
 
   // Push SDUs into RLC1
   const int n_sdus = 25;
   const int sdu_len = 100;
 
-  tester.set_expected_sdu_len(sdu_len);
+  ctxt.tester.set_expected_sdu_len(sdu_len);
-
 
   const int n_sdu_first_batch = 17;
 
@@ -280,7 +241,7 @@ int reassmble_test()
       sdu_bufs[i]->msg[k] = i;
     }
     sdu_bufs[i]->N_bytes = sdu_len; // Give each buffer a size of 1 byte
-    rlc1.write_sdu(std::move(sdu_bufs[i]));
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
   }
 
   // Read PDUs from RLC1 (use smaller grant for first PDU and large for the rest)
@@ -290,7 +251,7 @@ int reassmble_test()
   for(int i=0;i<max_n_pdus;i++)
   {
     pdu_bufs[i]          = byte_buffer_pool::get_instance()->allocate();
-    len                  = rlc1.read_pdu(pdu_bufs[i]->msg, (i == 0) ? sdu_len * 3 / 4 : sdu_len * 1.25);
+    int len              = ctxt.rlc1.read_pdu(pdu_bufs[i]->msg, (i == 0) ? sdu_len * 3 / 4 : sdu_len * 1.25);
     pdu_bufs[i]->N_bytes = len;
     if (len) {
       n_pdus++;
@@ -300,7 +261,7 @@ int reassmble_test()
   }
 
   printf("Generated %d PDUs in first batch\n", n_pdus);
-  TESTASSERT(0 == rlc1.get_buffer_state());
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
 
   // push second batch of SDUs
   for (int i = n_sdu_first_batch; i < n_sdus; ++i) {
@@ -309,14 +270,13 @@ int reassmble_test()
       sdu_bufs[i]->msg[k] = i;
     }
     sdu_bufs[i]->N_bytes = sdu_len; // Give each buffer a size of 1 byte
-    rlc1.write_sdu(std::move(sdu_bufs[i]));
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
   }
 
   // Read second batch of PDUs (use large grants)
-  for(int i=n_pdus;i<max_n_pdus;i++)
+  for (int i = n_pdus; i < max_n_pdus; i++) {
-  {
     pdu_bufs[i]          = byte_buffer_pool::get_instance()->allocate();
-    len                  = rlc1.read_pdu(pdu_bufs[i]->msg, sdu_len * 1.25);
+    int len              = ctxt.rlc1.read_pdu(pdu_bufs[i]->msg, sdu_len * 1.25);
     pdu_bufs[i]->N_bytes = len;
     if (len) {
       n_pdus++;
@@ -332,14 +292,14 @@ int reassmble_test()
   for(int i=0;i<n_pdus;i++)
   {
     if (i!=0) {
-      rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+      ctxt.rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
     }
   }
 
   // We should have received one SDU less than we tx'ed
-  TESTASSERT(tester.sdus.size() == n_sdus - 1);
+  TESTASSERT(ctxt.tester.sdus.size() == n_sdus - 1);
-  for (uint32_t i = 0; i < tester.sdus.size(); ++i) {
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); ++i) {
-    TESTASSERT(tester.sdus[i]->N_bytes == sdu_len);
+    TESTASSERT(ctxt.tester.sdus[i]->N_bytes == sdu_len);
   }
 
   return 0;
@@ -354,29 +314,18 @@ int reassmble_test()
 // Therefore, one SDU less should be received than was tx'ed.
 int reassmble_test2()
 {
-  srslte::log_filter log1("RLC_UM_1");
+  rlc_um_lte_test_context1 ctxt;
-  srslte::log_filter log2("RLC_UM_2");
-  log1.set_level(srslte::LOG_LEVEL_DEBUG);
-  log2.set_level(srslte::LOG_LEVEL_DEBUG);
-  log1.set_hex_limit(-1);
-  log2.set_hex_limit(-1);
-  rlc_um_tester         tester;
-  srslte::timer_handler timers(16);
-  int                   len = 0;
-
-  rlc_um rlc1(&log1, 3, &tester, &tester, &timers);
-  rlc_um rlc2(&log2, 3, &tester, &tester, &timers);
 
+  // reconfigure them with 5bit SNs
   rlc_config_t cnfg = rlc_config_t::default_rlc_um_config(5);
-
+  ctxt.rlc1.configure(cnfg);
-  rlc1.configure(cnfg);
+  ctxt.rlc2.configure(cnfg);
-  rlc2.configure(cnfg);
 
   // Push SDUs into RLC1
   const int n_sdus = 25;
   const int sdu_len = 100;
 
-  tester.set_expected_sdu_len(sdu_len);
+  ctxt.tester.set_expected_sdu_len(sdu_len);
 
   const int n_sdu_first_batch = 17;
   byte_buffer_pool*  pool              = byte_buffer_pool::get_instance();
@@ -387,16 +336,15 @@ int reassmble_test2()
       sdu_bufs[i]->msg[k] = i;
     }
     sdu_bufs[i]->N_bytes = sdu_len;
-    rlc1.write_sdu(std::move(sdu_bufs[i]));
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
   }
 
   const int max_n_pdus = 100;
   int n_pdus = 0;
   byte_buffer_t* pdu_bufs[max_n_pdus];
-  for(int i=0;i<max_n_pdus;i++)
+  for (int i = 0; i < max_n_pdus; i++) {
-  {
     pdu_bufs[i]          = byte_buffer_pool::get_instance()->allocate();
-    len                  = rlc1.read_pdu(pdu_bufs[i]->msg, (i == 0) ? sdu_len * .75 : sdu_len * .25);
+    int len              = ctxt.rlc1.read_pdu(pdu_bufs[i]->msg, (i == 0) ? sdu_len * .75 : sdu_len * .25);
     pdu_bufs[i]->N_bytes = len;
     if (len) {
       n_pdus++;
@@ -406,7 +354,7 @@ int reassmble_test2()
   }
 
   printf("Generated %d PDUs in first batch\n", n_pdus);
-  TESTASSERT(0 == rlc1.get_buffer_state());
+  TESTASSERT(0 == ctxt.rlc1.get_buffer_state());
 
   // push second batch of SDUs
   for (int i = n_sdu_first_batch; i < n_sdus; ++i) {
@@ -415,14 +363,14 @@ int reassmble_test2()
       sdu_bufs[i]->msg[k] = i;
     }
     sdu_bufs[i]->N_bytes = sdu_len; // Give each buffer a size of 1 byte
-    rlc1.write_sdu(std::move(sdu_bufs[i]));
+    ctxt.rlc1.write_sdu(std::move(sdu_bufs[i]));
   }
 
   // Read second batch of PDUs
   for(int i=n_pdus;i<max_n_pdus;i++)
   {
     pdu_bufs[i]          = byte_buffer_pool::get_instance()->allocate();
-    len                  = rlc1.read_pdu(pdu_bufs[i]->msg, sdu_len * 1.25);
+    int len              = ctxt.rlc1.read_pdu(pdu_bufs[i]->msg, sdu_len * 1.25);
     pdu_bufs[i]->N_bytes = len;
     if (len) {
       n_pdus++;
@@ -436,14 +384,14 @@ int reassmble_test2()
   // Write all PDUs into RLC2 except first one
   for(int i=0;i<n_pdus;i++) {
     if (i!=0) {
-      rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
+      ctxt.rlc2.write_pdu(pdu_bufs[i]->msg, pdu_bufs[i]->N_bytes);
     }
   }
 
   // We should have received one SDU less than we tx'ed
-  TESTASSERT(tester.sdus.size() == n_sdus - 1);
+  TESTASSERT(ctxt.tester.sdus.size() == n_sdus - 1);
-  for (uint32_t i = 0; i < tester.sdus.size(); ++i) {
+  for (uint32_t i = 0; i < ctxt.tester.sdus.size(); ++i) {
-    TESTASSERT(tester.sdus[i]->N_bytes == sdu_len);
+    TESTASSERT(ctxt.tester.sdus[i]->N_bytes == sdu_len);
   }
 
   return 0;