Add scheduling utility functions to check UL, DL, and mixed slot types in TDD config

* is_ul_slot: returns `true` for UL or mixed slots
* is_dl_slot: returns `true` for DL or mixed slots
* is_mixed_slot: returns `true` for mixed slots

These functions use the TDD slot bitmap for slot type checks

Co-authored-by: Guido Casati <guido.casati@firecell.io>

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c

@@ -126,6 +126,51 @@ bool is_xlsch_in_slot(uint64_t bitmap, sub_frame_t slot) {
   return (bitmap >> (slot % 64)) & 0x01;
 }
 
+/**
+ * @brief Returns true for:
+ *        (1) FDD
+ *        (2) Mixed slot with UL symbols
+ *        (3) Full UL slot
+ */
+bool is_ul_slot(const slot_t slot, const frame_structure_t *fs)
+{
+  if (!fs->is_tdd)
+    return true;
+  const tdd_period_config_t *pc = &fs->period_cfg;
+  slot_t s = get_slot_idx_in_period(slot, fs);
+  return ((is_mixed_slot(s, fs) && pc->tdd_slot_bitmap[s].num_ul_symbols)
+          || (pc->tdd_slot_bitmap[s].slot_type == TDD_NR_UPLINK_SLOT));
+}
+
+/**
+ * @brief Returns true for:
+ *        (1) FDD
+ *        (2) Mixed slot with DL symbols
+ *        (3) Full DL slot
+ */
+bool is_dl_slot(const slot_t slot, const frame_structure_t *fs)
+{
+  if (!fs->is_tdd)
+    return true;
+  const tdd_period_config_t *pc = &fs->period_cfg;
+  slot_t s = get_slot_idx_in_period(slot, fs);
+  return ((is_mixed_slot(s, fs) && pc->tdd_slot_bitmap[s].num_dl_symbols)
+          || (pc->tdd_slot_bitmap[s].slot_type == TDD_NR_DOWNLINK_SLOT));
+}
+
+/**
+ * @brief Returns true for:
+ *        (1) Mixed slot with DL and/or UL symbols
+ */
+bool is_mixed_slot(const slot_t slot, const frame_structure_t *fs)
+{
+  if (!fs->is_tdd)
+    return false;
+  slot_t s = get_slot_idx_in_period(slot, fs);
+  const tdd_period_config_t *pc = &fs->period_cfg;
+  return pc->tdd_slot_bitmap[s].slot_type == TDD_NR_MIXED_SLOT;
+}
+
 /* the structure nfapi_nr_ul_tti_request_t is very big, let's copy only what is necessary */
 static void copy_ul_tti_req(nfapi_nr_ul_tti_request_t *to, nfapi_nr_ul_tti_request_t *from)
 {

openair2/LAYER2/NR_MAC_gNB/mac_proto.h

@@ -353,6 +353,9 @@ int nr_write_ce_dlsch_pdu(module_id_t module_idP,
 int binomial(int n, int k);
 
 bool is_xlsch_in_slot(uint64_t bitmap, sub_frame_t slot);
+bool is_ul_slot(const slot_t slot, const frame_structure_t *fs);
+bool is_dl_slot(const slot_t slot, const frame_structure_t *fs);
+bool is_mixed_slot(const slot_t slot, const frame_structure_t *fs);
 
 /* \brief Function to indicate a received SDU on ULSCH.
 @param Mod_id Instance ID of gNB