diff --git a/openair1/PHY/NR_TRANSPORT/srs_rx.c b/openair1/PHY/NR_TRANSPORT/srs_rx.c
index d5731557a0..5d84c11c99 100644
--- a/openair1/PHY/NR_TRANSPORT/srs_rx.c
+++ b/openair1/PHY/NR_TRANSPORT/srs_rx.c
@@ -56,7 +56,8 @@ void nr_fill_srs(PHY_VARS_gNB *gNB, frame_t frame, slot_t slot, nfapi_nr_srs_pdu
       srs->active = true;
       srs->beam_nb = 0;
       if (gNB->common_vars.beam_id) {
-        int bitmap = SL_to_bitmap(srs_pdu->time_start_position, 1 << srs_pdu->num_symbols);
+        const uint8_t l0 = gNB->frame_parms.symbols_per_slot - 1 - srs_pdu->time_start_position;
+        int bitmap = SL_to_bitmap(l0, 1 << srs_pdu->num_symbols);
         int fapi_beam_idx = srs_pdu->beamforming.prgs_list[0].dig_bf_interface_list[0].beam_idx;
         srs->beam_nb = beam_index_allocation(gNB->enable_analog_das,
                                              fapi_beam_idx,
@@ -84,7 +85,7 @@ int nr_get_srs_signal(PHY_VARS_gNB *gNB,
   const NR_DL_FRAME_PARMS *frame_parms = &gNB->frame_parms;
 
   const uint16_t n_symbols = (slot % RU_RX_SLOT_DEPTH) * frame_parms->symbols_per_slot; // number of symbols until this slot
-  const uint8_t l0 = srs_pdu->time_start_position; // starting symbol in this slot
+  const uint8_t l0 = frame_parms->symbols_per_slot - 1 - srs_pdu->time_start_position; // starting symbol in this slot
   const uint64_t symbol_offset = (n_symbols + l0) * frame_parms->ofdm_symbol_size;
   const uint64_t subcarrier_offset = frame_parms->first_carrier_offset + srs_pdu->bwp_start * NR_NB_SC_PER_RB;
 
diff --git a/openair1/PHY/nr_phy_common/src/nr_phy_common_srs.c b/openair1/PHY/nr_phy_common/src/nr_phy_common_srs.c
index 9d91986b50..95b3a86d91 100644
--- a/openair1/PHY/nr_phy_common/src/nr_phy_common_srs.c
+++ b/openair1/PHY/nr_phy_common/src/nr_phy_common_srs.c
@@ -180,6 +180,11 @@ bool generate_srs_nr(const NR_DL_FRAME_PARMS *frame_parms,
   LOG_I(NR_PHY,"M_sc_b_SRS = %i\n", M_sc_b_SRS);
 #endif
 
+  AssertFatal(l0 + nr_srs_info->N_symb_SRS - 1 < frame_parms->symbols_per_slot,
+              "last symbol index %d should be < %d\n",
+              l0 + nr_srs_info->N_symb_SRS,
+              frame_parms->symbols_per_slot - 1);
+
   // Validation of SRS config parameters
 
   if (nr_srs_info->R == 0) {
diff --git a/openair1/SCHED_NR/phy_procedures_nr_gNB.c b/openair1/SCHED_NR/phy_procedures_nr_gNB.c
index 020d33039e..7e47f422e8 100644
--- a/openair1/SCHED_NR/phy_procedures_nr_gNB.c
+++ b/openair1/SCHED_NR/phy_procedures_nr_gNB.c
@@ -717,9 +717,10 @@ static void fill_ul_rb_mask(PHY_VARS_gNB *gNB,
     if (!(srs && srs->active && srs->frame == frame_rx && srs->slot == slot_rx))
       continue;
     nfapi_nr_srs_pdu_t *srs_pdu = &srs->srs_pdu;
+    const uint8_t l0 = gNB->frame_parms.symbols_per_slot - 1 - srs_pdu->time_start_position;
     for (int symbol = 0; symbol < (1 << srs_pdu->num_symbols); symbol++) {
       for (int rb = srs_pdu->bwp_start; rb < (srs_pdu->bwp_start + srs_pdu->bwp_size); rb++) {
-        rb_mask_ul[srs_pdu->time_start_position + symbol][rb >> 5] |= 1U << (rb & 31);
+        rb_mask_ul[l0 + symbol][rb >> 5] |= 1U << (rb & 31);
       }
     }
   }
diff --git a/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c b/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c
index bc2a803de8..b40a2ab063 100644
--- a/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c
+++ b/openair1/SCHED_NR_UE/phy_procedures_nr_ue.c
@@ -314,12 +314,13 @@ bool ue_srs_procedures_nr(PHY_VARS_NR_UE *ue,
     return false;
   }
 
+  NR_DL_FRAME_PARMS *frame_parms = &(ue->frame_parms);
   fapi_nr_ul_config_srs_pdu *srs_config_pdu = &phy_data->srs_vars.srs_config_pdu;
-  int first_srs_symbol = ue->frame_parms.symbols_per_slot - 1 - srs_config_pdu->time_start_position;
+  const uint8_t l0 = frame_parms->symbols_per_slot - 1 - srs_config_pdu->time_start_position;
   // Num consecutive SRS symbols according to 38.211 6.4.1.4.1
   int num_srs_symbols[] = {1, 2, 4, 8, 12};
-  int last_srs_symbol = first_srs_symbol + num_srs_symbols[srs_config_pdu->num_symbols] - 1;
-  for (int i = first_srs_symbol; i <= last_srs_symbol; i++) {
+  int last_srs_symbol = l0 + num_srs_symbols[srs_config_pdu->num_symbols] - 1;
+  for (int i = l0; i <= last_srs_symbol; i++) {
     was_symbol_used[i] = true;
   }
 
@@ -351,8 +352,7 @@ bool ue_srs_procedures_nr(PHY_VARS_NR_UE *ue,
 #endif
 
   configure_srs_info(srs_config_pdu, ue->nr_srs_info);
-  NR_DL_FRAME_PARMS *frame_parms = &(ue->frame_parms);
-  uint16_t symbol_offset = (frame_parms->symbols_per_slot - 1 - srs_config_pdu->time_start_position)*frame_parms->ofdm_symbol_size;
+  uint16_t symbol_offset = l0 * frame_parms->ofdm_symbol_size;
   bool generated = generate_srs_nr(frame_parms,
                                    txdataF,
                                    symbol_offset,
diff --git a/openair1/SIMULATION/NR_PHY/srssim.c b/openair1/SIMULATION/NR_PHY/srssim.c
index 0592bc42d1..fa7388498b 100644
--- a/openair1/SIMULATION/NR_PHY/srssim.c
+++ b/openair1/SIMULATION/NR_PHY/srssim.c
@@ -498,7 +498,7 @@ int main(int argc, char *argv[])
   bool was_symbol_used[NR_NUMBER_OF_SYMBOLS_PER_SLOT] = {0};
   int slot_offset = get_samples_slot_timestamp(fp, slot);
   uint16_t ofdm_symbol_size = fp->ofdm_symbol_size;
-  int slot_offsetF = (slot % RU_RX_SLOT_DEPTH) * NR_SYMBOLS_PER_SLOT * ofdm_symbol_size;
+  int slot_offsetF = (slot % RU_RX_SLOT_DEPTH) * fp->symbols_per_slot * ofdm_symbol_size;
 
   c16_t *txF[n_tx];
   for (i = 0; i < n_tx; i++)
@@ -528,10 +528,10 @@ int main(int argc, char *argv[])
   int symbol_offset = slot_offset;
   int abs_first_symbol = slot * fp->symbols_per_slot;
   int idx_sym;
-  for (idx_sym = abs_first_symbol; idx_sym < abs_first_symbol + srs_pdu.time_start_position; idx_sym++)
+  for (idx_sym = abs_first_symbol; idx_sym < abs_first_symbol + srs_start_symbol; idx_sym++)
     symbol_offset += (idx_sym % (0x7 << fp->numerology_index)) ? fp->nb_prefix_samples : fp->nb_prefix_samples0;
 
-  symbol_offset += ofdm_symbol_size * srs_pdu.time_start_position;
+  symbol_offset += ofdm_symbol_size * srs_start_symbol;
   int symbol_length = ofdm_symbol_size + (idx_sym % (0x7 << fp->numerology_index)) ? fp->nb_prefix_samples : fp->nb_prefix_samples0;
 
   // Compute transmitter energy level
diff --git a/openair1/SIMULATION/NR_PHY/ulsim.c b/openair1/SIMULATION/NR_PHY/ulsim.c
index c6e91d78aa..444492b545 100644
--- a/openair1/SIMULATION/NR_PHY/ulsim.c
+++ b/openair1/SIMULATION/NR_PHY/ulsim.c
@@ -1273,7 +1273,7 @@ int main(int argc, char *argv[])
           srs_pdu->subcarrier_spacing = gNB->frame_parms.subcarrier_spacing;
           srs_pdu->num_ant_ports = n_tx == 4 ? 2 : n_tx == 2 ? 1 : 0;
           srs_pdu->sequence_id = 40;
-          srs_pdu->time_start_position = gNB->frame_parms.symbols_per_slot - 1;
+          srs_pdu->time_start_position = 0;
           srs_pdu->config_index = rrc_get_max_nr_csrs(srs_pdu->bwp_size, srs_pdu->bandwidth_index);
           srs_pdu->resource_type = NR_SRS_Resource__resourceType_PR_periodic;
           srs_pdu->t_srs = 1;
@@ -1371,6 +1371,7 @@ int main(int argc, char *argv[])
           srs_config_pdu->sequence_id = 40;
           srs_config_pdu->resource_type = NR_SRS_Resource__resourceType_PR_periodic;
           srs_config_pdu->t_srs = 1;
+          srs_config_pdu->time_start_position = 0;
         }
 
         for (int i = 0; i < (TBS / 8); i++)
diff --git a/openair1/SIMULATION/tests/CMakeLists.txt b/openair1/SIMULATION/tests/CMakeLists.txt
index 98c8a53604..0c2ab8dd39 100644
--- a/openair1/SIMULATION/tests/CMakeLists.txt
+++ b/openair1/SIMULATION/tests/CMakeLists.txt
@@ -345,21 +345,22 @@ add_physim_test(physim.5g.nr_psbchsim.test2 "PSBCH TxRx" nr_psbchsim -n 30)
 ######                           nr_srssim unit test                          ######
 ####################################################################################
 
-add_physim_test(physim.5g.nr_srssim.test1 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 24, Combsize 2" nr_srssim -n300 -R106 -y2 -z2 -d 24)
-add_physim_test(physim.5g.nr_srssim.test2 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 15, Combsize 2, Threequarter sampling" nr_srssim -n300 -R106 -y2 -z2 -d 15 -k)
-add_physim_test(physim.5g.nr_srssim.test3 "SRS: 30KHz SCS, 217 PRBs, SNR 20 dB, ToA 8, Combsize 2" nr_srssim -n300 -R217 -y2 -z2 -d 8)
-add_physim_test(physim.5g.nr_srssim.test4 "SRS: 30KHz SCS, 273 PRBs, SNR 20 dB, TOA 30, Combsize 2" nr_srssim -n300 -R273 -y2 -z2 -d 30)
-add_physim_test(physim.5g.nr_srssim.test5 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 16, Combsize 2, Cyclic shift 3" nr_srssim -n300 -R106 -y2 -z2 -d 16 -i 1)
-add_physim_test(physim.5g.nr_srssim.test6 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 23, Combsize 2, Comb offset 1" nr_srssim -n300 -R106 -y2 -z2 -d 23 -f 1)
-add_physim_test(physim.5g.nr_srssim.test7 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 8, Combsize 2, Symbol start 9" nr_srssim -n300 -R106 -y2 -z2 -d 8 -a 9)
-add_physim_test(physim.5g.nr_srssim.test8 "SRS: 120KHz SCS, 32 PRBs, SNR 20 dB, ToA 19, Combsize 2" nr_srssim -n300 -R32 -y2 -z2 -d 19 -u 3)
-add_physim_test(physim.5g.nr_srssim.test9 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 11, Combsize 4" nr_srssim -n300 -R106 -y2 -z2 -d 11 -e 1)
-add_physim_test(physim.5g.nr_srssim.test10 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 7, Combsize 4, Comb offset 1" nr_srssim -n300 -R106 -y2 -z2 -d 7 -e 1 -f 1)
-add_physim_test(physim.5g.nr_srssim.test11 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 24, Combsize 2, SRS symbols 2" nr_srssim -n300 -R106 -y2 -z2 -d 24 -b 2)
-add_physim_test(physim.5g.nr_srssim.test12 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 24, Combsize 2, SRS symbols 4" nr_srssim -n300 -R106 -y2 -z2 -d 24 -b 4)
-add_physim_test(physim.5g.nr_srssim.test13 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 24, Combsize 4, SRS symbols 2" nr_srssim -n300 -R106 -y2 -z2 -d 24 -b 2 -e1)
-add_physim_test(physim.5g.nr_srssim.test14 "SRS: 30KHz SCS, 106 PRBs, SNR 20 dB, ToA 24, Combsize 4, SRS symbols 4" nr_srssim -n300 -R106 -y2 -z2 -d 24 -b 4 -e1)
-add_physim_test(physim.5g.nr_srssim.test15 "SRS: 30KHz SCS, 217 PRBs, SNR 20 dB, ToA 8, Combsize 2, SRS symbols 4" nr_srssim -n300 -R217 -y2 -z2 -d 8 -b 4)
+add_physim_test(physim.5g.nr_srssim.test1 "SRS: 30KHz SCS, 106 PRBs, ToA 24, Combsize 2" nr_srssim -n300 -R106 -s0 -S5 -y2 -z2 -d 24)
+add_physim_test(physim.5g.nr_srssim.test2 "SRS: 30KHz SCS, 106 PRBs, ToA 15, Combsize 2, Threequarter sampling" nr_srssim -n300 -R106 -s0 -S5 -y2 -z2 -d 15 -k)
+add_physim_test(physim.5g.nr_srssim.test3 "SRS: 30KHz SCS, 217 PRBs, ToA 8, Combsize 2" nr_srssim -n300 -R217 -s0 -S5 -y2 -z2 -d 8)
+add_physim_test(physim.5g.nr_srssim.test4 "SRS: 30KHz SCS, 273 PRBs, TOA 30, Combsize 2" nr_srssim -n300 -R273 -s0 -S5 -y2 -z2 -d 30)
+add_physim_test(physim.5g.nr_srssim.test5 "SRS: 30KHz SCS, 106 PRBs, ToA 16, Combsize 2, Cyclic shift 3" nr_srssim -n300 -R106 -s0 -S5 -y2 -z2 -d 16 -i 1)
+add_physim_test(physim.5g.nr_srssim.test6 "SRS: 30KHz SCS, 106 PRBs, ToA 23, Combsize 2, Comb offset 1" nr_srssim -n300 -R106 -s0 -S5 -y2 -z2 -d 23 -f 1)
+add_physim_test(physim.5g.nr_srssim.test7 "SRS: 30KHz SCS, 106 PRBs, ToA 8, Combsize 2, Symbol start 9" nr_srssim -n300 -R106 -s0 -S5 -y2 -z2 -d 8 -a 9)
+add_physim_test(physim.5g.nr_srssim.test8 "SRS: 120KHz SCS, 32 PRBs, ToA 19, Combsize 2" nr_srssim -n300 -R32 -s0 -S5 -y2 -z2 -d 19 -u 3)
+add_physim_test(physim.5g.nr_srssim.test9 "SRS: 30KHz SCS, 106 PRBs, ToA 11, Combsize 4" nr_srssim -n300 -R106 -s5 -S10 -y2 -z2 -d 11 -e 1)
+add_physim_test(physim.5g.nr_srssim.test10 "SRS: 30KHz SCS, 106 PRBs, ToA 7, Combsize 4, Comb offset 1" nr_srssim -n300 -R106 -s5 -S10 -y2 -z2 -d 7 -e 1 -f 1)
+add_physim_test(physim.5g.nr_srssim.test11 "SRS: 30KHz SCS, 106 PRBs, ToA 24, Combsize 2, SRS symbols 2, SRS start symbol 8" nr_srssim -n300 -R106 -s0 -S5 -y2 -z2 -d 24 -b 2 -a 8)
+add_physim_test(physim.5g.nr_srssim.test12 "SRS: 30KHz SCS, 106 PRBs, ToA 24, Combsize 2, SRS symbols 4, SRS start symbol 8" nr_srssim -n300 -R106 -s0 -S5 -y2 -z2 -d 24 -b 4 -a 8)
+add_physim_test(physim.5g.nr_srssim.test13 "SRS: 30KHz SCS, 106 PRBs, ToA 24, Combsize 4, SRS symbols 2, SRS start symbol 8" nr_srssim -n300 -R106 -s5 -S10 -y2 -z2 -d 24 -b 2 -e1 -a 8)
+add_physim_test(physim.5g.nr_srssim.test14 "SRS: 30KHz SCS, 106 PRBs, ToA 24, Combsize 4, SRS symbols 4, SRS start symbol 8" nr_srssim -n300 -R106 -s5 -S10 -y2 -z2 -d 24 -b 4 -e1 -a 8)
+add_physim_test(physim.5g.nr_srssim.test15 "SRS: 30KHz SCS, 217 PRBs, ToA 8, Combsize 2, SRS symbols 4, SRS start symbol 8" nr_srssim -n300 -R217 -s0 -S5 -y2 -z2 -d 8 -b 4 -a 8)
+add_physim_test(physim.5g.nr_srssim.test16 "SRS: 30KHz SCS, 106 PRBs, SNR 2 dB to 30 dB in steps of 5 dB, ToA 24, Combsize 2" nr_srssim -n300 -R106 -s2 -S30 -y2 -z2 -d 24)
 
 ####################################################################################
 ######                           offload-specific tests                       ######
diff --git a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_srs.c b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_srs.c
index 8c8a25e446..1afa2d1502 100644
--- a/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_srs.c
+++ b/openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_srs.c
@@ -428,7 +428,7 @@ static void nr_configure_srs(gNB_MAC_INST *nrmac,
   srs_pdu->num_ant_ports = srs_resource->nrofSRS_Ports;
   srs_pdu->num_symbols = srs_resource->resourceMapping.nrofSymbols;
   srs_pdu->num_repetitions = srs_resource->resourceMapping.repetitionFactor;
-  srs_pdu->time_start_position = NR_NUMBER_OF_SYMBOLS_PER_SLOT - 1 - srs_resource->resourceMapping.startPosition;
+  srs_pdu->time_start_position = srs_resource->resourceMapping.startPosition;
   srs_pdu->config_index = srs_resource->freqHopping.c_SRS;
   srs_pdu->sequence_id = srs_resource->sequenceId;
   srs_pdu->bandwidth_index = srs_resource->freqHopping.b_SRS;
@@ -479,7 +479,8 @@ static void nr_configure_srs(gNB_MAC_INST *nrmac,
   AssertFatal(beam.idx >= 0, "Cannot allocate SRS in any available beam\n");
   uint16_t *vrb_map_UL = &nrmac->common_channels[CC_id].vrb_map_UL[beam.idx][buffer_index * MAX_BWP_SIZE];
   uint16_t num = 1 << srs_pdu->num_symbols; // 0,1,2 means 1,2,4 symbols, see 222.10.04 table 3-105
-  uint16_t mask = SL_to_bitmap(srs_pdu->time_start_position, num);
+  const uint8_t l0 = NR_NUMBER_OF_SYMBOLS_PER_SLOT - 1 - srs_pdu->time_start_position;
+  uint16_t mask = SL_to_bitmap(l0, num);
   DevAssert(mask != 0);
   for (int i = 0; i < srs_pdu->bwp_size; ++i) {
     int rb = i + srs_pdu->bwp_start;