Lower scheduler PF averaging constant

This time constant plays a major role in how long a UE has to wait
maximally before it might be scheduled. For instance, if a UE had a lot
of traffic, the average traffic will be high, pushing the PF coefficient
down. If another UE with no traffic in the past becomes active with
heavy traffic, the first UE might not be scheduled for an extended
period of time.

In the AW2S-Amarisoft UE CI test pipeline, we sometimes see that the
maximum number of RLC retransmissions was reached. While this might not
be the (only) cause, scheduling a UE more often might prevent such
situations, and we saw an improved stability.

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c

@@ -614,7 +614,7 @@ static void pf_dl(module_id_t module_id,
     /* get the PID of a HARQ process awaiting retrnasmission, or -1 otherwise */
     sched_pdsch->dl_harq_pid = sched_ctrl->retrans_dl_harq.head;
     /* Calculate Throughput */
-    const float a = 0.0005f; // corresponds to 200ms window
+    const float a = 0.01f;
     const uint32_t b = UE->mac_stats.dl.current_bytes;
     UE->dl_thr_ue = (1 - a) * UE->dl_thr_ue + a * b;
 

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -1646,7 +1646,7 @@ static void pf_ul(module_id_t module_id,
     const NR_mac_dir_stats_t *stats = &UE->mac_stats.ul;
 
     /* Calculate throughput */
-    const float a = 0.0005f; // corresponds to 200ms window
+    const float a = 0.01f;
     const uint32_t b = stats->current_bytes;
     UE->ul_thr_ue = (1 - a) * UE->ul_thr_ue + a * b;