add configurable fairness parameter to pf scheduler

lib/include/srslte/interfaces/sched_interface.h

@@ -46,6 +46,7 @@ public:
 
   struct sched_args_t {
     std::string sched_policy         = "time_pf";
+    std::string sched_policy_args    = "2";
     int         pdsch_mcs            = -1;
     int         pdsch_max_mcs        = 28;
     int         pusch_mcs            = -1;

srsenb/hdr/stack/mac/schedulers/sched_time_pf.h

@@ -23,19 +23,20 @@ class sched_time_pf final : public sched_base
   using ue_cit_t = std::map<uint16_t, sched_ue>::const_iterator;
 
 public:
-  sched_time_pf(const sched_cell_params_t& cell_params_);
+  sched_time_pf(const sched_cell_params_t& cell_params_, const sched_interface::sched_args_t& sched_args);
   void sched_dl_users(std::map<uint16_t, sched_ue>& ue_db, sf_sched* tti_sched) override;
   void sched_ul_users(std::map<uint16_t, sched_ue>& ue_db, sf_sched* tti_sched) override;
 
 private:
   void new_tti(std::map<uint16_t, sched_ue>& ue_db, sf_sched* tti_sched);
 
-  const sched_cell_params_t* cc_cfg = nullptr;
+  const sched_cell_params_t* cc_cfg         = nullptr;
+  float                      fairness_coeff = 1;
 
   srslte::tti_point current_tti_rx;
 
   struct ue_ctxt {
-    ue_ctxt(uint16_t rnti_) : rnti(rnti_) {}
+    ue_ctxt(uint16_t rnti_, float fairness_coeff_) : rnti(rnti_), fairness_coeff(fairness_coeff_) {}
     float    dl_avg_rate() const { return dl_nof_samples == 0 ? 0 : dl_avg_rate_; }
     float    ul_avg_rate() const { return ul_nof_samples == 0 ? 0 : ul_avg_rate_; }
     uint32_t dl_count() const { return dl_nof_samples; }
@@ -45,6 +46,7 @@ private:
     void     save_ul_alloc(uint32_t alloc_bytes, float alpha);
 
     const uint16_t rnti;
+    const float    fairness_coeff;
 
     int                 ue_cc_idx  = 0;
     float               dl_prio    = 0;

srsenb/hdr/stack/mac/schedulers/sched_time_rr.h

@@ -22,7 +22,7 @@ class sched_time_rr final : public sched_base
   const static int MAX_RBG = 25;
 
 public:
-  sched_time_rr(const sched_cell_params_t& cell_params_);
+  sched_time_rr(const sched_cell_params_t& cell_params_, const sched_interface::sched_args_t& sched_args);
   void sched_dl_users(std::map<uint16_t, sched_ue>& ue_db, sf_sched* tti_sched) override;
   void sched_ul_users(std::map<uint16_t, sched_ue>& ue_db, sf_sched* tti_sched) override;
 

srsenb/src/main.cc

@@ -133,6 +133,7 @@ void parse_args(all_args_t* args, int argc, char* argv[])
 
     /* Scheduling section */
     ("scheduler.policy", bpo::value<string>(&args->stack.mac.sched.sched_policy)->default_value("time_pf"), "DL and UL data scheduling policy (E.g. time_rr, time_pf)")
+    ("scheduler.policy_args", bpo::value<string>(&args->stack.mac.sched.sched_policy_args)->default_value("2"), "Scheduler policy-specific arguments")
     ("scheduler.pdsch_mcs", bpo::value<int>(&args->stack.mac.sched.pdsch_mcs)->default_value(-1), "Optional fixed PDSCH MCS (ignores reported CQIs if specified)")
     ("scheduler.pdsch_max_mcs", bpo::value<int>(&args->stack.mac.sched.pdsch_max_mcs)->default_value(-1), "Optional PDSCH MCS limit")
     ("scheduler.pusch_mcs", bpo::value<int>(&args->stack.mac.sched.pusch_mcs)->default_value(-1), "Optional fixed PUSCH MCS (ignores reported CQIs if specified)")

srsenb/src/stack/mac/sched_carrier.cc

@@ -289,10 +289,10 @@ void sched::carrier_sched::carrier_cfg(const sched_cell_params_t& cell_params_)
 
   // Setup data scheduling algorithms
   if (cell_params_.sched_cfg->sched_policy == "time_rr") {
-    sched_algo.reset(new sched_time_rr{*cc_cfg});
+    sched_algo.reset(new sched_time_rr{*cc_cfg, *cell_params_.sched_cfg});
     log_h->info("Using time-domain RR scheduling policy for cc=%d\n", cc_cfg->enb_cc_idx);
   } else {
-    sched_algo.reset(new sched_time_pf{*cc_cfg});
+    sched_algo.reset(new sched_time_pf{*cc_cfg, *cell_params_.sched_cfg});
     log_h->info("Using time-domain PF scheduling policy for cc=%d\n", cc_cfg->enb_cc_idx);
   }
 

srsenb/src/stack/mac/schedulers/sched_time_pf.cc

@@ -16,9 +16,12 @@ namespace srsenb {
 
 using srslte::tti_point;
 
-sched_time_pf::sched_time_pf(const sched_cell_params_t& cell_params_)
+sched_time_pf::sched_time_pf(const sched_cell_params_t& cell_params_, const sched_interface::sched_args_t& sched_args)
 {
   cc_cfg = &cell_params_;
+  if (not sched_args.sched_policy_args.empty()) {
+    fairness_coeff = std::stof(sched_args.sched_policy_args);
+  }
 }
 
 void sched_time_pf::new_tti(std::map<uint16_t, sched_ue>& ue_db, sf_sched* tti_sched)
@@ -36,7 +39,7 @@ void sched_time_pf::new_tti(std::map<uint16_t, sched_ue>& ue_db, sf_sched* tti_s
   for (auto& u : ue_db) {
     auto it = ue_history_db.find(u.first);
     if (it == ue_history_db.end()) {
-      it = ue_history_db.insert(std::make_pair(u.first, ue_ctxt{u.first})).first;
+      it = ue_history_db.insert(std::make_pair(u.first, ue_ctxt{u.first, fairness_coeff})).first;
     }
     it->second.new_tti(*cc_cfg, u.second, tti_sched);
     if (it->second.dl_newtx_h != nullptr or it->second.dl_retx_h != nullptr) {
@@ -162,7 +165,7 @@ void sched_time_pf::ue_ctxt::new_tti(const sched_cell_params_t& cell, sched_ue&
     // calculate DL PF priority
     float r = ue.get_expected_dl_bitrate(ue_cc_idx) / 8;
     float R = dl_avg_rate();
-    dl_prio = (R != 0) ? r / R : (r == 0 ? 0 : std::numeric_limits<float>::max());
+    dl_prio = (R != 0) ? pow(r, fairness_coeff) / R : (r == 0 ? 0 : std::numeric_limits<float>::max());
   }
 
   // Calculate UL priority
@@ -177,24 +180,24 @@ void sched_time_pf::ue_ctxt::new_tti(const sched_cell_params_t& cell, sched_ue&
   }
 }
 
-void sched_time_pf::ue_ctxt::save_dl_alloc(uint32_t alloc_bytes, float alpha)
+void sched_time_pf::ue_ctxt::save_dl_alloc(uint32_t alloc_bytes, float exp_avg_alpha)
 {
-  if (dl_nof_samples < 1 / alpha) {
+  if (dl_nof_samples < 1 / exp_avg_alpha) {
     // fast start
     dl_avg_rate_ = dl_avg_rate_ + (alloc_bytes - dl_avg_rate_) / (dl_nof_samples + 1);
   } else {
-    dl_avg_rate_ = (1 - alpha) * dl_avg_rate_ + (alpha)*alloc_bytes;
+    dl_avg_rate_ = (1 - exp_avg_alpha) * dl_avg_rate_ + (exp_avg_alpha)*alloc_bytes;
   }
   dl_nof_samples++;
 }
 
-void sched_time_pf::ue_ctxt::save_ul_alloc(uint32_t alloc_bytes, float alpha)
+void sched_time_pf::ue_ctxt::save_ul_alloc(uint32_t alloc_bytes, float exp_avg_alpha)
 {
-  if (ul_nof_samples < 1 / alpha) {
+  if (ul_nof_samples < 1 / exp_avg_alpha) {
     // fast start
     ul_avg_rate_ = ul_avg_rate_ + (alloc_bytes - ul_avg_rate_) / (ul_nof_samples + 1);
   } else {
-    ul_avg_rate_ = (1 - alpha) * ul_avg_rate_ + (alpha)*alloc_bytes;
+    ul_avg_rate_ = (1 - exp_avg_alpha) * ul_avg_rate_ + (exp_avg_alpha)*alloc_bytes;
   }
   ul_nof_samples++;
 }

srsenb/src/stack/mac/schedulers/sched_time_rr.cc

@@ -15,7 +15,7 @@
 
 namespace srsenb {
 
-sched_time_rr::sched_time_rr(const sched_cell_params_t& cell_params_)
+sched_time_rr::sched_time_rr(const sched_cell_params_t& cell_params_, const sched_interface::sched_args_t& sched_args)
 {
   cc_cfg = &cell_params_;
 }
@@ -65,9 +65,13 @@ void sched_time_rr::sched_dl_newtxs(std::map<uint16_t, sched_ue>& ue_db, sf_sche
     if (iter == ue_db.end()) {
       iter = ue_db.begin(); // wrap around
     }
-    sched_ue&           user     = iter->second;
+    sched_ue& user      = iter->second;
+    int       ue_cc_idx = user.enb_to_ue_cc_idx(cc_cfg->enb_cc_idx);
+    if (ue_cc_idx < 0) {
+      continue;
+    }
     const dl_harq_proc* h        = get_dl_newtx_harq(user, tti_sched);
-    rbg_interval        req_rbgs = user.get_required_dl_rbgs(user.enb_to_ue_cc_idx(cc_cfg->enb_cc_idx));
+    rbg_interval        req_rbgs = user.get_required_dl_rbgs(ue_cc_idx);
     // Check if there is an empty harq for the newtx
     if (h == nullptr or req_rbgs.stop() == 0) {
       continue;