diff --git a/openair1/SIMULATION/NR_PHY/ulsim.c b/openair1/SIMULATION/NR_PHY/ulsim.c
index e267c8b6d7..8d6355a6ea 100644
--- a/openair1/SIMULATION/NR_PHY/ulsim.c
+++ b/openair1/SIMULATION/NR_PHY/ulsim.c
@@ -672,6 +672,13 @@ int main(int argc, char **argv)
   char tp_param[] = "n";
   initTpool(tp_param, gNB->threadPool, true);
   initNotifiedFIFO(gNB->respDecode);
+  gNB->resp_L1_tx = (notifiedFIFO_t*) malloc(sizeof(notifiedFIFO_t));
+  initNotifiedFIFO(gNB->resp_L1_tx);
+  notifiedFIFO_elt_t *msgL1Tx = newNotifiedFIFO_elt(sizeof(processingData_L1tx_t),0,gNB->resp_L1_tx,NULL);
+  processingData_L1tx_t *msgDataTx = (processingData_L1tx_t *)NotifiedFifoData(msgL1Tx);
+  msgDataTx->slot = -1;
+  gNB->phy_proc_tx_0 = &msgDataTx->phy_proc_tx;
+  pushNotifiedFIFO(gNB->resp_L1_tx,msgL1Tx); // to unblock the process in the beginning
   //gNB_config = &gNB->gNB_config;
 
   //memset((void *)&gNB->UL_INFO,0,sizeof(gNB->UL_INFO));