gw: calculate GW throughput based on TTI timing

similiar like the RLC patch, MAC TTIs are passed to GW so the
rx/tx rate can be calculated based on the LTE timing

srsue/hdr/stack/upper/gw.h

@@ -43,7 +43,7 @@ public:
   int  init(const gw_args_t& args_, srslte::logger* logger_, stack_interface_gw* stack);
   void stop();
 
-  void get_metrics(gw_metrics_t& m);
+  void get_metrics(gw_metrics_t& m, const uint32_t nof_tti);
 
   // PDCP interface
   void write_pdu(uint32_t lcid, srslte::unique_byte_buffer_t pdu);
@@ -82,8 +82,8 @@ private:
   uint32_t current_ip_addr = 0;
   uint8_t  current_if_id[8];
 
-  long           ul_tput_bytes = 0;
-  long           dl_tput_bytes = 0;
+  uint32_t       ul_tput_bytes = 0;
+  uint32_t       dl_tput_bytes = 0;
   struct timeval metrics_time[3];
 
   void run_thread();

srsue/src/stack/upper/gw.cc

@@ -84,15 +84,24 @@ void gw::stop()
   }
 }
 
-void gw::get_metrics(gw_metrics_t& m)
+void gw::get_metrics(gw_metrics_t& m, const uint32_t nof_tti)
 {
   gettimeofday(&metrics_time[2], NULL);
   get_time_interval(metrics_time);
-  double secs = (double)metrics_time[0].tv_sec + metrics_time[0].tv_usec * 1e-6;
 
-  m.dl_tput_mbps = (dl_tput_bytes * 8 / (double)1e6) / secs;
-  m.ul_tput_mbps = (ul_tput_bytes * 8 / (double)1e6) / secs;
-  log.info("RX throughput: %4.6f Mbps. TX throughput: %4.6f Mbps.\n", m.dl_tput_mbps, m.ul_tput_mbps);
+  double secs                   = (double)metrics_time[0].tv_sec + metrics_time[0].tv_usec * 1e-6;
+  double dl_tput_mbps_real_time = (dl_tput_bytes * 8 / (double)1e6) / secs;
+  double ul_tput_mbps_real_time = (ul_tput_bytes * 8 / (double)1e6) / secs;
+
+  // Use the provided TTI counter to compute rate for metrics interface
+  m.dl_tput_mbps = (dl_tput_bytes * 8 / (double)1e6) / (nof_tti / 1000.0);
+  m.ul_tput_mbps = (ul_tput_bytes * 8 / (double)1e6) / (nof_tti / 1000.0);
+
+  log.info("gw_rx_rate_mbps=%4.2f (real=%4.2f), gw_tx_rate_mbps=%4.2f (real=%4.2f)\n",
+           m.dl_tput_mbps,
+           dl_tput_mbps_real_time,
+           m.ul_tput_mbps,
+           ul_tput_mbps_real_time);
 
   memcpy(&metrics_time[1], &metrics_time[2], sizeof(struct timeval));
   dl_tput_bytes = 0;

srsue/src/ue.cc

@@ -298,7 +298,7 @@ bool ue::get_metrics(ue_metrics_t* m)
   phy->get_metrics(&m->phy);
   radio->get_metrics(&m->rf);
   stack->get_metrics(&m->stack);
-  gw_inst->get_metrics(m->gw);
+  gw_inst->get_metrics(m->gw, m->stack.mac[0].nof_tti);
   return true;
 }