perform PUCCH+PRACH PRB reservation right at the start of a new TTI in the scheduler

srsenb/hdr/stack/mac/scheduler_carrier.h

@@ -65,10 +65,6 @@ private:
   std::unique_ptr<metric_ul>    ul_metric;
   const uint32_t                enb_cc_idx;
 
-  // derived from args
-  prbmask_t prach_mask;
-  prbmask_t pucch_mask;
-
   // Subframe scheduling logic
   std::array<sf_sched, TTIMOD_SZ> sf_scheds;
 

srsenb/hdr/stack/mac/scheduler_grid.h

@@ -326,6 +326,7 @@ private:
   const sched_cell_params_t* cc_cfg = nullptr;
   srslte::log_ref            log_h;
   sf_sched_result*           cc_results; ///< Results of other CCs for the same Subframe
+  prbmask_t                  pucch_mask;
 
   // internal state
   sf_grid_t                tti_alloc;

srsenb/src/stack/mac/scheduler_carrier.cc

@@ -297,15 +297,6 @@ void sched::carrier_sched::carrier_cfg(const sched_cell_params_t& cell_params_)
   ul_metric.reset(new srsenb::ul_metric_rr{});
   ul_metric->set_params(*cc_cfg);
 
-  // Setup constant PUCCH/PRACH mask
-  pucch_mask.resize(cc_cfg->nof_prb());
-  if (cc_cfg->cfg.nrb_pucch > 0) {
-    pucch_mask.fill(0, (uint32_t)cc_cfg->cfg.nrb_pucch);
-    pucch_mask.fill(cc_cfg->nof_prb() - cc_cfg->cfg.nrb_pucch, cc_cfg->nof_prb());
-  }
-  prach_mask.resize(cc_cfg->nof_prb());
-  prach_mask.fill(cc_cfg->cfg.prach_freq_offset, cc_cfg->cfg.prach_freq_offset + 6);
-
   // Initiate the tti_scheduler for each TTI
   for (sf_sched& tti_sched : sf_scheds) {
     tti_sched.init(*cc_cfg);
@@ -391,17 +382,6 @@ void sched::carrier_sched::alloc_dl_users(sf_sched* tti_result)
 
 int sched::carrier_sched::alloc_ul_users(sf_sched* tti_sched)
 {
-  uint32_t tti_tx_ul = tti_sched->get_tti_tx_ul();
-
-  /* reserve PRBs for PRACH */
-  if (srslte_prach_tti_opportunity_config_fdd(cc_cfg->cfg.prach_config, tti_tx_ul, -1)) {
-    tti_sched->reserve_ul_prbs(prach_mask, false);
-    log_h->debug("SCHED: Allocated PRACH RBs. Mask: 0x%s\n", prach_mask.to_hex().c_str());
-  }
-
-  /* reserve PRBs for PUCCH */
-  tti_sched->reserve_ul_prbs(pucch_mask, cc_cfg->nof_prb() != 6);
-
   /* Call scheduler for UL data */
   ul_metric->sched_users(*ue_db, tti_sched);
 

srsenb/src/stack/mac/scheduler_grid.cc

@@ -570,6 +570,12 @@ void sf_sched::init(const sched_cell_params_t& cell_params_)
   cc_cfg = &cell_params_;
   tti_alloc.init(*cc_cfg);
   max_msg3_prb = std::max(6u, cc_cfg->cfg.cell.nof_prb - (uint32_t)cc_cfg->cfg.nrb_pucch);
+
+  pucch_mask.resize(cc_cfg->nof_prb());
+  if (cc_cfg->cfg.nrb_pucch > 0) {
+    pucch_mask.fill(0, (uint32_t)cc_cfg->cfg.nrb_pucch);
+    pucch_mask.fill(cc_cfg->nof_prb() - cc_cfg->cfg.nrb_pucch, cc_cfg->nof_prb());
+  }
 }
 
 void sf_sched::new_tti(uint32_t tti_rx_, sf_sched_result* cc_results_)
@@ -584,6 +590,17 @@ void sf_sched::new_tti(uint32_t tti_rx_, sf_sched_result* cc_results_)
   tti_alloc.new_tti(tti_params);
   cc_results = cc_results_;
 
+  // Reserve PRBs for PUCCH
+  reserve_ul_prbs(pucch_mask, true);
+
+  // Reserve PRBs for PRACH
+  if (srslte_prach_tti_opportunity_config_fdd(cc_cfg->cfg.prach_config, tti_params.tti_tx_ul, -1)) {
+    prbmask_t prach_mask{cc_cfg->nof_prb()};
+    prach_mask.fill(cc_cfg->cfg.prach_freq_offset, cc_cfg->cfg.prach_freq_offset + 6);
+    reserve_ul_prbs(prach_mask, cc_cfg->nof_prb() != 6);
+    log_h->debug("SCHED: Allocated PRACH RBs. Mask: 0x%s\n", prach_mask.to_hex().c_str());
+  }
+
   // setup first prb to be used for msg3 alloc. Account for potential PRACH alloc
   last_msg3_prb           = cc_cfg->cfg.nrb_pucch;
   uint32_t tti_msg3_alloc = TTI_ADD(tti_params.tti_tx_ul, MSG3_DELAY_MS);