xran integration improvements

- identification of each parameter in fh_init and fh_config structs - identification of unused parameters in xran library - identification of parameters used for CAT A O-RU => CAT B not supported in this release
2026-07-15 21:50:27 +00:00 · 2024-11-12 16:38:42 +01:00
parent 530f96278d
commit f30453968f
2 changed files with 183 additions and 191 deletions
--- a/radio/fhi_72/oran-config.c
+++ b/radio/fhi_72/oran-config.c
@@ -27,6 +27,7 @@
 #include "xran_fh_o_du.h"
 #include "xran_cp_api.h"
 #include "rte_ether.h"
+#include <rte_ethdev.h>

 #include "stdio.h"
 #include "string.h"
@@ -234,13 +235,14 @@ void print_fh_init(const struct xran_fh_init *fh_init)
  dpdkBasebandFecMode %d\n\
  dpdkBasebandDevice %s\n\
  filePrefix %s\n\
-  mtu %d\n",
+  mtu %d\n\
+  p_o_du_addr %s\n",
      fh_init->xran_ports,
      fh_init->dpdkBasebandFecMode,
      fh_init->dpdkBasebandDevice,
      fh_init->filePrefix,
-      fh_init->mtu);
-  print_ether_addr("  p_o_du_addr", fh_init->xran_ports * fh_init->io_cfg.num_vfs, (struct rte_ether_addr *)fh_init->p_o_du_addr);
+      fh_init->mtu,
+      fh_init->p_o_du_addr);
  print_ether_addr("  p_o_ru_addr", fh_init->xran_ports * fh_init->io_cfg.num_vfs, (struct rte_ether_addr *)fh_init->p_o_ru_addr);
  printf("\
  totalBfWeights %d\n",
@@ -448,15 +450,19 @@ void print_fh_config(const struct xran_fh_config *fh_config)
  printf("\
  bbdev_enc %p\n\
  bbdev_dec %p\n\
-  tx_cp_eAxC2Vf [not implemented by fhi_lib]\n\
-  tx_up_eAxC2Vf [not implemented by fhi_lib]\n\
-  rx_cp_eAxC2Vf [not implemented by fhi_lib]\n\
-  rx_up_eAxC2Vf [not implemented by fhi_lib]\n\
+  tx_cp_eAxC2Vf %p\n\
+  tx_up_eAxC2Vf %p\n\
+  rx_cp_eAxC2Vf %p\n\
+  rx_up_eAxC2Vf %p\n\
  log_level %d\n\
  max_sections_per_slot %d\n\
  max_sections_per_symbol %d\n",
      fh_config->bbdev_enc,
      fh_config->bbdev_dec,
+      fh_config->tx_cp_eAxC2Vf,
+      fh_config->tx_up_eAxC2Vf,
+      fh_config->rx_cp_eAxC2Vf,
+      fh_config->rx_up_eAxC2Vf,
      fh_config->log_level,
      fh_config->max_sections_per_slot,
      fh_config->max_sections_per_symbol);
@@ -483,52 +489,66 @@ static uint64_t get_u64_mask(const paramdef_t *pd)
  return mask;
 }

-static bool set_fh_io_cfg(struct xran_io_cfg *io_cfg, const paramdef_t *fhip, int nump)
+static bool set_fh_io_cfg(struct xran_io_cfg *io_cfg, const paramdef_t *fhip, int nump, const int num_rus)
 {
  DevAssert(fhip != NULL);
  int num_dev = gpd(fhip, nump, ORAN_CONFIG_DPDK_DEVICES)->numelt;
  AssertFatal(num_dev > 0, "need to provide DPDK devices for O-RAN 7.2 Fronthaul\n");
  AssertFatal(num_dev < 17, "too many DPDK devices for O-RAN 7.2 Fronthaul\n");

-  io_cfg->id = 0; // 0 = O-DU
-  io_cfg->num_vfs = num_dev;
-  io_cfg->num_rxq = 2; // Assume two HW RX queues per RU
-  for (int i = 0; i < num_dev; ++i)
-    io_cfg->dpdk_dev[i] = strdup(gpd(fhip, nump, ORAN_CONFIG_DPDK_DEVICES)->strlistptr[i]);
-  //io_cfg->bbdev_dev = NULL;
-  io_cfg->bbdev_mode = XRAN_BBDEV_NOT_USED; // none
-  io_cfg->dpdkIoVaMode = 0; /* IOVA mode */
-  io_cfg->dpdkMemorySize = *gpd(fhip, nump, ORAN_CONFIG_DPDK_MEM_SIZE)->uptr;
-  io_cfg->core = *gpd(fhip, nump, ORAN_CONFIG_IO_CORE)->iptr;
-  io_cfg->system_core = *gpd(fhip, nump, ORAN_CONFIG_SYSTEM_CORE)->iptr;
-  io_cfg->pkt_proc_core = get_u64_mask(gpd(fhip, nump, ORAN_CONFIG_WORKER_CORES));
-  io_cfg->pkt_proc_core_64_127 = 0x0; // bitmap 0 -> no core
-  io_cfg->pkt_aux_core = 0; /* sapmle app says 0 = "do not start" */
-  io_cfg->timing_core = *gpd(fhip, nump, ORAN_CONFIG_IO_CORE)->iptr; /* sample app: equal to io_core */
-  //io_cfg->port = {0}; // all 0
-  io_cfg->io_sleep = 0; // no sleep
-  io_cfg->nEthLinePerPort = *gpd(fhip, nump, ORAN_CONFIG_NETHPERPORT)->uptr;
-  io_cfg->nEthLineSpeed = *gpd(fhip, nump, ORAN_CONFIG_NETHSPEED)->uptr;
-  io_cfg->one_vf_cu_plane = 0; // false: C/U-plane don't share VF
-  // io_cfg->eowd_cmn[0] // all 0
-  // io_cfg->eowd_cmn[1] // all 0
-  // io_cfg->eowd_port[0]... // all 0
+  io_cfg->id = 0; // 0 -> xran as O-DU; 1 -> xran as O-RU
+  io_cfg->num_vfs = num_dev; // number of VFs for C-plane and U-plane (should be even); max = XRAN_VF_MAX
+  io_cfg->num_rxq = 1; // number of RX queues per VF
+  for (int i = 0; i < num_dev; ++i) {
+    io_cfg->dpdk_dev[i] = strdup(gpd(fhip, nump, ORAN_CONFIG_DPDK_DEVICES)->strlistptr[i]); // VFs devices
+  }
+  io_cfg->bbdev_dev[0] = NULL; // BBDev dev name; max devices = 1
+  io_cfg->bbdev_mode = XRAN_BBDEV_NOT_USED; // DPDK for BBDev
+  io_cfg->dpdkIoVaMode = 0; // IOVA mode
+  io_cfg->dpdkMemorySize = *gpd(fhip, nump, ORAN_CONFIG_DPDK_MEM_SIZE)->uptr; // DPDK max memory allocation
+
+  /* the following core assignment is needed for rte_eal_init() function within xran library;
+    these parameters are machine specific */
+  io_cfg->core = *gpd(fhip, nump, ORAN_CONFIG_IO_CORE)->iptr; // core used for IO; absolute CPU core ID for xran library, it should be an isolated core
+  io_cfg->system_core = *gpd(fhip, nump, ORAN_CONFIG_SYSTEM_CORE)->iptr; // absolute CPU core ID for DPDK control threads, it should be an isolated core
+  io_cfg->pkt_proc_core = get_u64_mask(gpd(fhip, nump, ORAN_CONFIG_WORKER_CORES)); // worker mask 0-63
+  io_cfg->pkt_proc_core_64_127 = 0x0; // worker mask 64-127; to be used if machine supports more than 64 cores
+  io_cfg->pkt_aux_core = 0; // sample app says 0 = "do not start"
+  io_cfg->timing_core = *gpd(fhip, nump, ORAN_CONFIG_IO_CORE)->iptr; // core used by xran
+
+  // io_cfg->port[XRAN_VF_MAX] // VFs ports; filled within xran library
+  io_cfg->io_sleep = 0; // enable sleep on PMD cores; 0 -> no sleep
+  io_cfg->nEthLinePerPort = *gpd(fhip, nump, ORAN_CONFIG_NETHPERPORT)->uptr; // 1, 2, 3 total number of links per O-RU (Fronthaul Ethernet link)
+  io_cfg->nEthLineSpeed = *gpd(fhip, nump, ORAN_CONFIG_NETHSPEED)->uptr; // 10G,25G,40G,100G speed of Physical connection on O-RU
+  io_cfg->one_vf_cu_plane = (io_cfg->num_vfs == num_rus); // C-plane and U-plane use one VF
+
+  /* use owdm to calculate T12 and T34 -> CUS specification, section 2.3.3.3 */
+  // io_cfg->eowd_cmn[2] // ecpri one-way delay measurements common settings for O-DU and O-RU
+  // io_cfg->eowd_port[2][XRAN_VF_MAX] // ecpri owd measurements per port variables for O-DU and O-RU

  return true;
 }

 static bool set_fh_eaxcid_conf(struct xran_eaxcid_config *eaxcid_conf, enum xran_category cat)
 {
-  // values taken from sample app
+  /* CUS specification, section 3.1.3.1.6
+    DU_port_ID - used to differentiate processing units at O-DU (e.g., different baseband cards).
+    BandSector_ID - aggregated cell identifier (distinguishes bands and sectors supported by the O-RU).
+    CC_ID - distinguishes Carrier Components supported by the O-RU.
+    RU_Port_ID - designates logical flows such as data layers or spatial streams, and logical flows such as separate
+                 numerologies (e.g. PRACH) or signaling channels requiring special antenna assignments such as SRS.
+    The assignment of the DU_port_ID, BandSector_ID, CC_ID, and RU_Port_ID
+    as part of the eAxC ID is done solely by the O-DU via the M-plane.
+    Each ID field has a flexible bit allocation, but the total eAxC ID field length is fixed, 16 bits. */
  switch (cat) {
    case XRAN_CATEGORY_A:
      eaxcid_conf->mask_cuPortId = 0xf000;
      eaxcid_conf->mask_bandSectorId = 0x0f00;
      eaxcid_conf->mask_ccId = 0x00f0;
      eaxcid_conf->mask_ruPortId = 0x000f;
-      eaxcid_conf->bit_cuPortId = 12;
-      eaxcid_conf->bit_bandSectorId = 8;
-      eaxcid_conf->bit_ccId = 4;
+      eaxcid_conf->bit_cuPortId = 0;
+      eaxcid_conf->bit_bandSectorId = 0; // total number of band sectors supported by O-RU should be retreived by M-plane - <max-num-bands> && <max-num-sectors>
+      eaxcid_conf->bit_ccId = 0; // total number of CC supported by O-RU should be retreived by M-plane - <max-num-component-carriers>
      eaxcid_conf->bit_ruPortId = 0;
      break;
    case XRAN_CATEGORY_B:
@@ -560,7 +580,7 @@ uint8_t *get_ether_addr(const char *addr, struct rte_ether_addr *ether_addr)
  return NULL;
 }

-static bool set_fh_init(struct xran_fh_init *fh_init)
+static bool set_fh_init(struct xran_fh_init *fh_init, enum xran_category xran_cat)
 {
  memset(fh_init, 0, sizeof(*fh_init));

@@ -588,42 +608,28 @@ static bool set_fh_init(struct xran_fh_init *fh_init)
  sprintf(aprefix, "%s", CONFIG_STRING_ORAN);
  const int nfh = sizeofArray(FHconfigs);
  config_getlist(config_get_if(), &FH_ConfigList, FHconfigs, nfh, aprefix);
-  int num_rus = FH_ConfigList.numelt;
-  int num_ru_addr = gpd(fhip, nump, ORAN_CONFIG_RU_ADDR)->numelt;
-  int num_du_addr = gpd(fhip, nump, ORAN_CONFIG_DU_ADDR)->numelt;
-  int num_vfs = gpd(fhip, nump, ORAN_CONFIG_DPDK_DEVICES)->numelt;
-  if (num_ru_addr != num_du_addr) {
-    printf("need to have same number of DUs and RUs!\n");
-    return false;
-  }
-  if (num_ru_addr != num_vfs) {
-    printf("need to have as many RU/DU entries as DPDK devices (one VF for CP and UP each)\n");
-    return false;
-  }

-  if (!set_fh_io_cfg(&fh_init->io_cfg, fhip, nump))
+  int num_rus = FH_ConfigList.numelt; // based on the number of fh_config sections -> number of RUs
+
+  if (!set_fh_io_cfg(&fh_init->io_cfg, fhip, nump, num_rus))
    return false;
-  if (!set_fh_eaxcid_conf(&fh_init->eAxCId_conf, XRAN_CATEGORY_A))
+  if (!set_fh_eaxcid_conf(&fh_init->eAxCId_conf, xran_cat))
    return false;

-  fh_init->xran_ports = num_rus;
-  fh_init->dpdkBasebandFecMode = 0;
-  fh_init->dpdkBasebandDevice = NULL;
-  fh_init->filePrefix = strdup(*gpd(fhip, nump, ORAN_CONFIG_FILE_PREFIX)->strptr); // see DPDK --file-prefix
+  fh_init->xran_ports = num_rus; // since we use xran as O-DU, xran_ports is set to the number of RUs
+  fh_init->dpdkBasebandFecMode = 0; // DPDK Baseband FEC device mode (0-SW, 1-HW); not used in xran
+  fh_init->dpdkBasebandDevice = NULL; // DPDK Baseband device address; not used in xran
+  /* used to specify a unique prefix for shared memory, and files created by multiple DPDK processes;
+    is it necessary */
+  fh_init->filePrefix = strdup(*gpd(fhip, nump, ORAN_CONFIG_FILE_PREFIX)->strptr);
+  /* maximum transmission unit (MTU) is the size of the largest protocol data unit (PDU) that can be
+    communicated in a single xRAN network layer transaction. Supported 1500 bytes and 9600 bytes (Jumbo Frame);
+    xran only checks if (MTU <= 1500), therefore setting any value > 1500, xran assumes 9600 value is used */
  fh_init->mtu = *gpd(fhip, nump, ORAN_CONFIG_MTU)->uptr;

-  // if multiple RUs: xran_ethdi_init_dpdk_io() iterates over
-  // &p_o_ru_addr[i]
-  char **du_addrs = gpd(fhip, nump, ORAN_CONFIG_DU_ADDR)->strlistptr;
-  fh_init->p_o_du_addr = calloc(num_du_addr, sizeof(struct rte_ether_addr));
-  AssertFatal(fh_init->p_o_du_addr != NULL, "out of memory\n");
-  for (int i = 0; i < num_du_addr; ++i) {
-    struct rte_ether_addr *ea = (struct rte_ether_addr *)fh_init->p_o_du_addr;
-    if (get_ether_addr(du_addrs[i], &ea[i]) == NULL) {
-      printf("could not read ethernet address '%s' for DU!\n", du_addrs[i]);
-      return false;
-    }
-  }
+  fh_init->p_o_du_addr = NULL; // DPDK retreives DU MAC address within the xran library with rte_eth_macaddr_get() function
+
+  int num_ru_addr = gpd(fhip, nump, ORAN_CONFIG_RU_ADDR)->numelt;
  fh_init->p_o_ru_addr = calloc(num_ru_addr, sizeof(struct rte_ether_addr));
  char **ru_addrs = gpd(fhip, nump, ORAN_CONFIG_RU_ADDR)->strlistptr;
  AssertFatal(fh_init->p_o_ru_addr != NULL, "out of memory\n");
@@ -634,42 +640,12 @@ static bool set_fh_init(struct xran_fh_init *fh_init)
      return false;
    }
  }
-  fh_init->totalBfWeights = 32;
+
+  fh_init->totalBfWeights = 0; // only used if id = O_RU (for emulation); C-plane extension types; section 5.4.6 of CUS spec

  return true;
 }

-static enum xran_cp_filterindex get_prach_filterindex_fr1(duplex_mode_t mode, int prach_index)
-{
-  if (mode == duplex_mode_TDD) {
-    // 38.211 table 6.3.3.2-3 "unpaired spectrum" -> TDD
-    switch (prach_index) {
-      case 0 ... 39:
-      case 256 ... 262:
-        return XRAN_FILTERINDEX_PRACH_012;
-      case 40 ... 66:
-        return XRAN_FILTERINDEX_PRACH_3;
-      case 67 ... 255:
-        return XRAN_FILTERINDEX_PRACH_ABC;
-    }
-  } else if (mode == duplex_mode_FDD) {
-    // 38.211 table 6.3.3.2-2 "paired spectrum" -> FDD
-    switch (prach_index) {
-      case 0 ... 59:
-        return XRAN_FILTERINDEX_PRACH_012;
-      case 60 ... 86:
-        return XRAN_FILTERINDEX_PRACH_3;
-      case 87 ... 255:
-        return XRAN_FILTERINDEX_PRACH_ABC;
-      default:
-        AssertFatal(false, "unknown PRACH index %d\n", prach_index);
-    }
-  } else {
-    AssertFatal(false, "unsupported duplex mode %d\n", mode);
-  }
-  return XRAN_FILTERINDEX_STANDARD;
-}
-
 // PRACH guard interval. Raymond: "[it] is not in the configuration, (i.e. it
 // is deterministic depending on others). LiteON must hard-code this in the
 // O-RU itself, benetel doesn't (as O-RAN specifies). So we will need to tell
@@ -678,73 +654,82 @@ static enum xran_cp_filterindex get_prach_filterindex_fr1(duplex_mode_t mode, in
 int g_kbar;

 static bool set_fh_prach_config(const openair0_config_t *oai0,
+                                const uint32_t max_num_ant,
                                const paramdef_t *prachp,
                                int nprach,
                                struct xran_prach_config *prach_config)
 {
  const split7_config_t *s7cfg = &oai0->split7;

-  prach_config->nPrachConfIdx = s7cfg->prach_index;
-  prach_config->nPrachSubcSpacing = oai0->nr_scs_for_raster;
-  prach_config->nPrachZeroCorrConf = 0;
-  prach_config->nPrachRestrictSet = 0;
-  prach_config->nPrachRootSeqIdx = 0;
-  prach_config->nPrachFreqStart = s7cfg->prach_freq_start;
-  prach_config->nPrachFreqOffset = (s7cfg->prach_freq_start * 12 - oai0->num_rb_dl * 6) * 2;
-  if (oai0->nr_band < 100)
-    prach_config->nPrachFilterIdx = get_prach_filterindex_fr1(oai0->duplex_mode, s7cfg->prach_index);
-  else
-    prach_config->nPrachFilterIdx = XRAN_FILTERINDEX_PRACH_ABC;
+  prach_config->nPrachConfIdx = s7cfg->prach_index; // PRACH Configuration Index
+  prach_config->nPrachSubcSpacing = oai0->nr_scs_for_raster; // 0 -> 15kHz, 1 -> 30kHz, 2 -> 60kHz, 3 -> 120kHz
+  prach_config->nPrachZeroCorrConf = 0; // PRACH zeroCorrelationZoneConfig; should be saved from config file; not used in xran
+  prach_config->nPrachRestrictSet = 0; /* PRACH restrictedSetConfig; should be saved from config file; 0 = unrestricted,
+                                          1 = restricted type A, 2=restricted type B; not used in xran */
+  prach_config->nPrachRootSeqIdx = 0; // PRACH Root Sequence Index; should be saved from config file; 1 = 839, 2 = 139; not used in xran
+  prach_config->nPrachFreqStart = s7cfg->prach_freq_start; // PRACH frequency start (MSG1)
+  prach_config->nPrachFreqOffset = (s7cfg->prach_freq_start * 12 - oai0->num_rb_dl * 6) * 2; // PRACH frequency offset
+  prach_config->nPrachFilterIdx = 0; /* PRACH filter index; not used in xran;
+                                        in E release hardcoded to XRAN_FILTERINDEX_PRACH_ABC (preamble format A1~3, B1~4, C0, C2)
+                                        in F release properly calculated */
+
+  /* Return values after initialization */
  prach_config->startSymId = 0;
  prach_config->lastSymId = 0;
  prach_config->startPrbc = 0;
  prach_config->numPrbc = 0;
  prach_config->timeOffset = 0;
  prach_config->freqOffset = 0;
-  prach_config->eAxC_offset = *gpd(prachp, nprach, ORAN_PRACH_CONFIG_EAXC_OFFSET)->u8ptr;
+
+  /* xran defines PDSCH eAxC IDs as [0...Ntx-1];
+     xran defines PUSCH eAxC IDs as [0...Nrx-1];
+     PRACH offset must be >= max(Ntx, Nrx) */
+  uint8_t offset = *gpd(prachp, nprach, ORAN_PRACH_CONFIG_EAXC_OFFSET)->u8ptr;
+  prach_config->eAxC_offset = (offset != 0) ? offset : max_num_ant;

  g_kbar = *gpd(prachp, nprach, ORAN_PRACH_CONFIG_KBAR)->uptr;

  return true;
 }

-static bool set_fh_srs_config(struct xran_srs_config *srs_config)
-{
-  srs_config->symbMask = 0;
-  srs_config->eAxC_offset = 8;
-  return true;
-}
-
 static bool set_fh_frame_config(const openair0_config_t *oai0, struct xran_frame_config *frame_config)
 {
  const split7_config_t *s7cfg = &oai0->split7;
-  frame_config->nFrameDuplexType = oai0->duplex_mode == duplex_mode_TDD ? XRAN_TDD : XRAN_FDD;
-  frame_config->nNumerology = oai0->nr_scs_for_raster;
+  frame_config->nFrameDuplexType = oai0->duplex_mode == duplex_mode_TDD ? XRAN_TDD : XRAN_FDD; // Frame Duplex type:  0 -> FDD, 1 -> TDD
+  frame_config->nNumerology = oai0->nr_scs_for_raster; /* 0 -> 15kHz,  1 -> 30kHz,  2 -> 60kHz
+                                                          3 -> 120kHz, 4 -> 240kHz */
+
+  if (frame_config->nFrameDuplexType == XRAN_FDD)
+    return true;
+
+  // TDD periodicity
  frame_config->nTddPeriod = s7cfg->n_tdd_period;

+  // TDD Slot configuration
  struct xran_slot_config *sc = &frame_config->sSlotConfig[0];
  for (int slot = 0; slot < frame_config->nTddPeriod; ++slot)
    for (int sym = 0; sym < 14; ++sym)
      sc[slot].nSymbolType[sym] = s7cfg->slot_dirs[slot].sym_dir[sym];
+
  return true;
 }

-static bool set_fh_ru_config(const paramdef_t *rup, uint16_t fftSize, int nru, struct xran_ru_config *ru_config)
+static bool set_fh_ru_config(const paramdef_t *rup, uint16_t fftSize, int nru, enum xran_category xran_cat, struct xran_ru_config *ru_config)
 {
-  ru_config->xranTech = XRAN_RAN_5GNR;
-  ru_config->xranCat = XRAN_CATEGORY_A;
-  ru_config->xranCompHdrType = XRAN_COMP_HDR_TYPE_STATIC;
-  ru_config->iqWidth = *gpd(rup, nru, ORAN_RU_CONFIG_IQWIDTH)->uptr;
+  ru_config->xranTech = XRAN_RAN_5GNR; // 5GNR or LTE
+  ru_config->xranCat = xran_cat; // mode: Catergory A or Category B
+  ru_config->xranCompHdrType = XRAN_COMP_HDR_TYPE_STATIC; // dynamic or static udCompHdr handling
+  ru_config->iqWidth = *gpd(rup, nru, ORAN_RU_CONFIG_IQWIDTH)->uptr; // IQ bit width
  AssertFatal(ru_config->iqWidth <= 16, "IQ Width cannot be > 16!\n");
-  ru_config->compMeth = ru_config->iqWidth < 16 ? XRAN_COMPMETHOD_BLKFLOAT : XRAN_COMPMETHOD_NONE;
-  ru_config->iqWidth_PRACH = *gpd(rup, nru, ORAN_RU_CONFIG_IQWIDTH_PRACH)->uptr;
+  ru_config->compMeth = ru_config->iqWidth < 16 ? XRAN_COMPMETHOD_BLKFLOAT : XRAN_COMPMETHOD_NONE; // compression method
+  ru_config->iqWidth_PRACH = *gpd(rup, nru, ORAN_RU_CONFIG_IQWIDTH_PRACH)->uptr; // IQ bit width for PRACH
  AssertFatal(ru_config->iqWidth_PRACH <= 16, "IQ Width for PRACH cannot be > 16!\n");
-  ru_config->compMeth_PRACH = ru_config->iqWidth_PRACH < 16 ? XRAN_COMPMETHOD_BLKFLOAT : XRAN_COMPMETHOD_NONE;
+  ru_config->compMeth_PRACH = ru_config->iqWidth_PRACH < 16 ? XRAN_COMPMETHOD_BLKFLOAT : XRAN_COMPMETHOD_NONE; // compression method for PRACH
  AssertFatal(fftSize > 0, "FFT size cannot be 0\n");
-  ru_config->fftSize = fftSize;
-  ru_config->byteOrder = XRAN_NE_BE_BYTE_ORDER;
-  ru_config->iqOrder = XRAN_I_Q_ORDER;
-  ru_config->xran_max_frame = 0;
+  ru_config->fftSize = fftSize; // FFT Size
+  ru_config->byteOrder = XRAN_NE_BE_BYTE_ORDER; // order of bytes in int16_t in buffer; big or little endian
+  ru_config->iqOrder = XRAN_I_Q_ORDER; // order of IQs in the buffer
+  ru_config->xran_max_frame = 0; // max frame number supported; if not specified, default of 1023 is used
  return true;
 }

@@ -764,14 +749,12 @@ static bool set_maxmin_pd(const paramdef_t *pd, int num, const char *name, uint1
  return true;
 }

-extern uint32_t to_nrarfcn(int nr_bandP, uint64_t dl_CarrierFreq, uint8_t scs_index, uint32_t bw);
-static bool set_fh_config(int ru_idx, int num_rus, const openair0_config_t *oai0, struct xran_fh_config *fh_config)
+static bool set_fh_config(int ru_idx, int num_rus, enum xran_category xran_cat, const openair0_config_t *oai0, struct xran_fh_config *fh_config)
 {
  AssertFatal(num_rus == 1 || num_rus == 2, "only support 1 or 2 RUs as of now\n");
  AssertFatal(ru_idx < num_rus, "illegal ru_idx %d: must be < %d\n", ru_idx, num_rus);
  DevAssert(oai0->tx_num_channels > 0 && oai0->rx_num_channels > 0);
  DevAssert(oai0->tx_bw > 0 && oai0->rx_bw > 0);
-  //AssertFatal(oai0->tx_num_channels == oai0->rx_num_channels, "cannot handle unequal number of TX/RX channels\n");
  DevAssert(oai0->tx_freq[0] > 0);
  for (int i = 1; i < oai0->tx_num_channels; ++i)
    DevAssert(oai0->tx_freq[0] == oai0->tx_freq[i]);
@@ -782,12 +765,6 @@ static bool set_fh_config(int ru_idx, int num_rus, const openair0_config_t *oai0
  DevAssert(oai0->nr_scs_for_raster > 0);
  AssertFatal(oai0->threequarter_fs == 0, "cannot use three-quarter sampling with O-RAN 7.2 split\n");

-  // we simply assume that the loading process provides function to_nrarfcn()
-  // to calculate the ARFCN numbers from frequency. That is not clean, but the
-  // best we can do without copy-pasting the function.
-  uint32_t nDLCenterFreqARFCN = to_nrarfcn(oai0->nr_band, oai0->tx_freq[0], oai0->nr_scs_for_raster, oai0->tx_bw);
-  uint32_t nULCenterFreqARFCN = to_nrarfcn(oai0->nr_band, oai0->rx_freq[0], oai0->nr_scs_for_raster, oai0->rx_bw);
-
  paramdef_t FHconfigs[] = ORAN_FH_DESC;
  paramlist_def_t FH_ConfigList = {CONFIG_STRING_ORAN_FH};
  char aprefix[MAX_OPTNAME_SIZE] = {0};
@@ -819,30 +796,30 @@ static bool set_fh_config(int ru_idx, int num_rus, const openair0_config_t *oai0

  memset(fh_config, 0, sizeof(*fh_config));

-  fh_config->dpdk_port = ru_idx;
-  fh_config->sector_id = 0;
-  fh_config->nCC = 1;
-  fh_config->neAxc = oai0->tx_num_channels / num_rus;
-  fh_config->neAxcUl = oai0->rx_num_channels / num_rus;
-  fh_config->nAntElmTRx = oai0->tx_num_channels / num_rus;
-  fh_config->nDLFftSize = 0;
-  fh_config->nULFftSize = 0;
-  fh_config->nDLRBs = oai0->num_rb_dl;
-  fh_config->nULRBs = oai0->num_rb_dl;
-  fh_config->nDLAbsFrePointA = 0;
-  fh_config->nULAbsFrePointA = 0;
-  fh_config->nDLCenterFreqARFCN = nDLCenterFreqARFCN;
-  fh_config->nULCenterFreqARFCN = nULCenterFreqARFCN;
-  fh_config->ttiCb = NULL;
-  fh_config->ttiCbParam = NULL;
-  fh_config->Tadv_cp_dl = *gpd(fhp, nfh, ORAN_FH_CONFIG_TADV_CP_DL)->uptr;
-  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_T2A_CP_DL, &fh_config->T2a_min_cp_dl, &fh_config->T2a_max_cp_dl))
+  fh_config->dpdk_port = ru_idx; // DPDK port number used for FH
+  fh_config->sector_id = 0; // Band sector ID for FH; not used in xran
+  fh_config->nCC = 1; // number of Component carriers supported on FH; M-plane info
+  fh_config->neAxc = RTE_MAX(oai0->tx_num_channels / num_rus, oai0->rx_num_channels / num_rus); // number of eAxc supported on one CC = max(PDSCH, PUSCH)
+  fh_config->neAxcUl = 0; // number of eAxc supported on one CC for UL direction = PUSCH; used only if XRAN_CATEGORY_B
+  fh_config->nAntElmTRx = 0; // number of antenna elements for TX and RX = SRS; used only if XRAN_CATEGORY_B
+  fh_config->nDLFftSize = 0; // DL FFT size; not used in xran
+  fh_config->nULFftSize = 0; // UL FFT size; not used in xran
+  fh_config->nDLRBs = oai0->num_rb_dl; // DL PRB
+  fh_config->nULRBs = oai0->num_rb_dl; // UL PRB; in xran not used as id = O_DU,  but used in oaioran.c/oran-init.c
+  fh_config->nDLAbsFrePointA = 0; // Abs Freq Point A of the Carrier Center Frequency for in KHz Value; not used in xran
+  fh_config->nULAbsFrePointA = 0; // Abs Freq Point A of the Carrier Center Frequency for in KHz Value; not used in xran
+  fh_config->nDLCenterFreqARFCN = 0; // center frequency for DL in NR-ARFCN; not used in xran
+  fh_config->nULCenterFreqARFCN = 0; // center frequency for UL in NR-ARFCN; not used in xran
+  fh_config->ttiCb = NULL; // check tti_to_phy_cb(), tx_cp_dl_cb() and tx_cp_ul_cb => first_call
+  fh_config->ttiCbParam = NULL; // check tti_to_phy_cb(), tx_cp_dl_cb() and tx_cp_ul_cb => first_call
+  fh_config->Tadv_cp_dl = *gpd(fhp, nfh, ORAN_FH_CONFIG_TADV_CP_DL)->uptr; // not used in xran
+  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_T2A_CP_DL, &fh_config->T2a_min_cp_dl, &fh_config->T2a_max_cp_dl)) // not used in xran
    return false;
-  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_T2A_CP_UL, &fh_config->T2a_min_cp_ul, &fh_config->T2a_max_cp_ul))
+  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_T2A_CP_UL, &fh_config->T2a_min_cp_ul, &fh_config->T2a_max_cp_ul)) // not used in xran
    return false;
-  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_T2A_UP, &fh_config->T2a_min_up, &fh_config->T2a_max_up))
+  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_T2A_UP, &fh_config->T2a_min_up, &fh_config->T2a_max_up)) // not used in xran
    return false;
-  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_TA3, &fh_config->Ta3_min, &fh_config->Ta3_max))
+  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_TA3, &fh_config->Ta3_min, &fh_config->Ta3_max)) // not used in xran
    return false;
  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_T1A_CP_DL, &fh_config->T1a_min_cp_dl, &fh_config->T1a_max_cp_dl))
    return false;
@@ -852,50 +829,67 @@ static bool set_fh_config(int ru_idx, int num_rus, const openair0_config_t *oai0
    return false;
  if (!set_maxmin_pd(fhp, nfh, ORAN_FH_CONFIG_TA4, &fh_config->Ta4_min, &fh_config->Ta4_max))
    return false;
-  fh_config->enableCP = 1;
-  fh_config->prachEnable = 1;
-  fh_config->srsEnable = 0;
-  fh_config->puschMaskEnable = 0;
-  fh_config->puschMaskSlot = 0;
-  fh_config->cp_vlan_tag = *gpd(fhp, nfh, ORAN_FH_CONFIG_CP_VLAN_TAG)->uptr;
-  fh_config->up_vlan_tag = *gpd(fhp, nfh, ORAN_FH_CONFIG_UP_VLAN_TAG)->uptr;
-  fh_config->debugStop = 0;
-  fh_config->debugStopCount = 0;
-  fh_config->DynamicSectionEna = 0;
-  fh_config->GPS_Alpha = 0;
-  fh_config->GPS_Beta = 0;
+  fh_config->enableCP = 1; // enable C-plane
+  fh_config->prachEnable = 1; // enable PRACH
+  fh_config->srsEnable = 0; // enable SRS; used only if XRAN_CATEGORY_B
+  fh_config->puschMaskEnable = 0; // enable PUSCH mask; only used if id = O_RU
+  fh_config->puschMaskSlot = 0; // specific which slot PUSCH channel masked; only used if id = O_RU
+  fh_config->cp_vlan_tag = *gpd(fhp, nfh, ORAN_FH_CONFIG_CP_VLAN_TAG)->uptr; // C-plane VLAN tag; not used in xran; needed for M-plane
+  fh_config->up_vlan_tag = *gpd(fhp, nfh, ORAN_FH_CONFIG_UP_VLAN_TAG)->uptr; // U-plane VLAN tag; not used in xran; needed for M-plane
+  fh_config->debugStop = 0; // enable auto stop; not used in xran
+  fh_config->debugStopCount = 0; // enable auto stop after number of Tx packets; not used in xran
+  fh_config->DynamicSectionEna = 0; // enable dynamic C-Plane section allocation; not used in xran
+  fh_config->GPS_Alpha = 0; // refers to alpha as defined in section 9.7.2 of ORAN spec. this value should be alpha*(1/1.2288ns), range 0 - 1e7 (ns); offset_nsec = (pConf->GPS_Beta - offset_sec * 100) * 1e7 + pConf->GPS_Alpha
+  fh_config->GPS_Beta = 0; // beta value as defined in section 9.7.2 of ORAN spec. range -32767 ~ +32767; offset_sec = pConf->GPS_Beta / 100

-  if (!set_fh_prach_config(oai0, prachp, nprach, &fh_config->prach_conf))
-    return false;
-  if (!set_fh_srs_config(&fh_config->srs_conf))
+  if (!set_fh_prach_config(oai0, fh_config->neAxc, prachp, nprach, &fh_config->prach_conf))
    return false;
+  /* SRS only used if XRAN_CATEGORY_B
+    Note: srs_config->eAxC_offset >= prach_config->eAxC_offset + PRACH */
+  // fh_config->srs_conf = {0};
  if (!set_fh_frame_config(oai0, &fh_config->frame_conf))
    return false;
-  if (!set_fh_ru_config(rup, oai0->split7.fftSize, nru, &fh_config->ru_conf))
+  if (!set_fh_ru_config(rup, oai0->split7.fftSize, nru, xran_cat, &fh_config->ru_conf))
    return false;

-  fh_config->bbdev_enc = NULL;
-  fh_config->bbdev_dec = NULL;
-  // fh_config->tx_cp_eAxC2Vf [not implemented by fhi_lib]
-  // fh_config->tx_up_eAxC2Vf [not implemented by fhi_lib]
-  // fh_config->rx_cp_eAxC2Vf [not implemented by fhi_lib]
-  // fh_config->rx_up_eAxC2Vf [not implemented by fhi_lib]
-  fh_config->log_level = 1;
-  fh_config->max_sections_per_slot = 8;
-  fh_config->max_sections_per_symbol = 8;
+  fh_config->bbdev_enc = NULL; // call back to poll BBDev encoder
+  fh_config->bbdev_dec = NULL; // call back to poll BBDev decoder
+
+  /* CUS specification, section 3.1.3.1.6 
+    This parameter is an eAxC identifier (eAxC ID) and identifies the specific data flow associated with each
+    C-Plane (ecpriRtcid) or U-Plane (ecpriPcid) message.
+    Each of bellow parameters is a matrix [XRAN_MAX_SECTOR_NR][XRAN_MAX_ANTENNA_NR*2 + XRAN_MAX_ANT_ARRAY_ELM_NR] */
+  // fh_config->tx_cp_eAxC2Vf // mapping of C-Plane (ecpriRtcid) to VF; not used in xran
+  // fh_config->tx_up_eAxC2Vf // mapping of U-Plane (ecpriPcid) to VF; not used in xran
+  // fh_config->rx_cp_eAxC2Vf // mapping of C-Plane (ecpriRtcid) to VF; not used in xran
+  // fh_config->rx_up_eAxC2Vf // mapping of U-Plane (ecpriPcid) to VF; not used in xran
+
+  fh_config->log_level = 1; // configuration of log level; 1 -> enabled
+
+  /* Parameters that should be retreived via M-plane
+    O-RU defines them for Section Type 1 (Most DL/UL radio channels) and 3 (PRACH and mixed-numerology channels)
+    Note: When PRACH having same numerology as other UL channels, Section type 1 can alternatively be used by O-DU for PRACH signaling.
+          In this case, O-RU is not expected to perform any PRACH specific processing. */
+  fh_config->max_sections_per_slot = 0; // not used in xran
+  fh_config->max_sections_per_symbol = 0; // not used in xran

  return true;
 }

 bool get_xran_config(const openair0_config_t *openair0_cfg, struct xran_fh_init *fh_init, struct xran_fh_config *fh_config)
 {
-  if (!set_fh_init(fh_init)) {
+  /* This xran integration release is only valid for O-RU CAT A.
+    Therefore, each FH parameter is hardcoded to CAT A.
+    If you are interested in CAT B, please be aware that parameters of fh_init and fh_config structs must be modified accordingly. */
+  enum xran_category xran_cat = XRAN_CATEGORY_A;
+
+  if (!set_fh_init(fh_init, xran_cat)) {
    printf("could not read FHI 7.2/ORAN config\n");
    return false;
  }

  for (int32_t o_xu_id = 0; o_xu_id < fh_init->xran_ports; o_xu_id++) {
-    if (!set_fh_config(o_xu_id, fh_init->xran_ports, openair0_cfg, &fh_config[o_xu_id])) {
+    if (!set_fh_config(o_xu_id, fh_init->xran_ports, xran_cat, openair0_cfg, &fh_config[o_xu_id])) {
      printf("could not read FHI 7.2/RU-specific config\n");
      return false;
    }
--- a/radio/fhi_72/oran-params.h
+++ b/radio/fhi_72/oran-params.h
@@ -31,7 +31,6 @@
 #define ORAN_CONFIG_SYSTEM_CORE "system_core"
 #define ORAN_CONFIG_IO_CORE "io_core"
 #define ORAN_CONFIG_WORKER_CORES "worker_cores"
-#define ORAN_CONFIG_DU_ADDR "du_addr"
 #define ORAN_CONFIG_RU_ADDR "ru_addr"
 #define ORAN_CONFIG_MTU "mtu"
 #define ORAN_CONFIG_FILE_PREFIX "file_prefix"
@@ -47,9 +46,8 @@
  {ORAN_CONFIG_SYSTEM_CORE,     "DPDK control threads core\n",              PARAMFLAG_MANDATORY, .iptr=NULL,       .defintval=0,        TYPE_INT,        0}, \
  {ORAN_CONFIG_IO_CORE,         "DPDK Core used for IO\n",                  PARAMFLAG_MANDATORY, .iptr=NULL,       .defintval=4,        TYPE_INT,        0}, \
  {ORAN_CONFIG_WORKER_CORES,    "CPU Cores to use for workers\n",           PARAMFLAG_MANDATORY, .uptr=NULL,       .defintarrayval=NULL,TYPE_UINTARRAY,  0}, \
-  {ORAN_CONFIG_DU_ADDR,         "Ether addr of DU\n",                       PARAMFLAG_MANDATORY, .strlistptr=NULL, .defstrlistval=NULL, TYPE_STRINGLIST, 0}, \
  {ORAN_CONFIG_RU_ADDR,         "Ether addr of RU\n",                       PARAMFLAG_MANDATORY, .strlistptr=NULL, .defstrlistval=NULL, TYPE_STRINGLIST, 0}, \
-  {ORAN_CONFIG_MTU,             "MTU of Eth interface\n",                   PARAMFLAG_MANDATORY, .uptr=NULL,       .defuintval=1500,    TYPE_UINT,       0}, \
+  {ORAN_CONFIG_MTU,             "MTU of Eth interface\n",                   0,                   .uptr=NULL,       .defuintval=1500,    TYPE_UINT,       0}, \
  {ORAN_CONFIG_FILE_PREFIX,     "DPDK file-prefix\n",                       0,                   .strptr=NULL,     .defstrval="wls_0",  TYPE_STRING,     0}, \
  {ORAN_CONFIG_NETHPERPORT,     "number of links per port\n",               0,                   .uptr=NULL,       .defuintval=1,       TYPE_UINT,       0}, \
  {ORAN_CONFIG_NETHSPEED,       "ethernet speed link\n",                    0,                   .uptr=NULL,       .defuintval=10,      TYPE_UINT,       0}, \