diff --git a/srsapps/ue/phy/include/srsapps/ue/phy/phy.h b/srsapps/ue/phy/include/srsapps/ue/phy/phy.h
index 564a4da16..f93e65f64 100644
--- a/srsapps/ue/phy/include/srsapps/ue/phy/phy.h
+++ b/srsapps/ue/phy/include/srsapps/ue/phy/phy.h
@@ -152,10 +152,7 @@ private:
   bool         do_agc;
   double       last_gain;
   
-  uint32_t     sr_N_offset;
-  uint32_t     sr_periodicity;
   bool         sr_enabled;
-  uint32_t     sr_n_pucch;
   bool         sr_is_ready_to_send(uint32_t tti);
   
   bool         init_(radio *radio_handler, tti_sync *ttisync, log *log_h, bool do_agc);
diff --git a/srsapps/ue/phy/include/srsapps/ue/phy/phy_params.h b/srsapps/ue/phy/include/srsapps/ue/phy/phy_params.h
index 44fa2402f..02aed5a4f 100644
--- a/srsapps/ue/phy/include/srsapps/ue/phy/phy_params.h
+++ b/srsapps/ue/phy/include/srsapps/ue/phy/phy_params.h
@@ -77,7 +77,6 @@ namespace ue {
       PUCCH_N_PUCCH_2,
       PUCCH_N_PUCCH_SR,
 
-      SR_PUCCH_RESINDEX,
       SR_CONFIG_INDEX,
 
       UCI_I_OFFSET_ACK,
diff --git a/srsapps/ue/phy/src/phy.cc b/srsapps/ue/phy/src/phy.cc
index 6a8ab0724..2483075e5 100644
--- a/srsapps/ue/phy/src/phy.cc
+++ b/srsapps/ue/phy/src/phy.cc
@@ -153,15 +153,6 @@ bool phy::send_prach(uint32_t preamble_idx, int allowed_subframe, int target_pow
 /* Send SR as soon as possible as defined in Section 10.2 of 36.213 */
 void phy::send_sr(bool enable)
 {
-
-  if (enable) {
-    // Get sr_periodicity and sr_N_offset from table 10.1-5
-    uint32_t I_sr = params_db.get_param(phy_params::SR_CONFIG_INDEX);
-    sr_n_pucch = params_db.get_param(phy_params::SR_PUCCH_RESINDEX);
-    srslte_ue_ul_sr_config(I_sr, &sr_periodicity, &sr_N_offset);
-    Info("SR I_sr=%d, periodicity=%d, N_offset=%d, n_pucch=%d\n", I_sr, sr_periodicity, sr_N_offset, sr_n_pucch);
-    sr_tx_tti = get_current_tti(); 
-  }
   sr_enabled = enable;
 }
 
@@ -175,10 +166,12 @@ int phy::sr_last_tx_tti() {
 
 bool phy::sr_is_ready_to_send(uint32_t tti_) {
   if (sr_enabled) {
-    if ((10*tti_to_SFN(tti_)+tti_to_subf(tti_)-sr_N_offset)%sr_periodicity==0) {
+    // Get I_sr parameter
+    uint32_t I_sr = params_db.get_param(phy_params::SR_CONFIG_INDEX);
+    if (srslte_ue_ul_sr_send_tti(I_sr, tti_)) {
       sr_enabled = false;
       sr_tx_tti = tti_; 
-      Debug("SR ready to send for TTI=%d\n", tti_);
+      Info("SR ready to send for TTI=%d\n", tti_);
       return true; 
     }
   }
diff --git a/srslte/include/srslte/ue/ue_ul.h b/srslte/include/srslte/ue/ue_ul.h
index 06efd70c4..82084c888 100644
--- a/srslte/include/srslte/ue/ue_ul.h
+++ b/srslte/include/srslte/ue/ue_ul.h
@@ -151,8 +151,7 @@ SRSLTE_API void srslte_ue_ul_set_rnti(srslte_ue_ul_t *q,
 
 /* Other static functions for UL PHY procedures defined in 36.213 */
 
-SRSLTE_API int srslte_ue_ul_sr_config(uint32_t I_sr, 
-                                      uint32_t *sr_periodicity, 
-                                      uint32_t *sr_N_offset);
+SRSLTE_API int srslte_ue_ul_sr_send_tti(uint32_t I_sr, 
+                                        uint32_t current_tti);
 
 #endif
diff --git a/srslte/lib/phch/test/prach_test_usrp.c b/srslte/lib/phch/test/prach_test_usrp.c
index a2647e77b..c5bfd9577 100644
--- a/srslte/lib/phch/test/prach_test_usrp.c
+++ b/srslte/lib/phch/test/prach_test_usrp.c
@@ -175,7 +175,7 @@ int main(int argc, char **argv) {
     if (nframe==9 || nframe==8) {
       srslte_timestamp_add(&tstamp, 0, 2e-3);
       if (nframe==8) {
-        //cuhd_send_timed2(uhd, zeros, flen, tstamp.full_secs, tstamp.frac_secs, true, false);      
+        cuhd_send_timed2(uhd, zeros, flen, tstamp.full_secs, tstamp.frac_secs, true, false);      
         printf("Transmitting zeros\n");        
       } else {
         cuhd_send_timed2(uhd, preamble, flen, tstamp.full_secs, tstamp.frac_secs, true, true);      
diff --git a/srslte/lib/ue/src/ue_ul.c b/srslte/lib/ue/src/ue_ul.c
index 982b386aa..450a34c16 100644
--- a/srslte/lib/ue/src/ue_ul.c
+++ b/srslte/lib/ue/src/ue_ul.c
@@ -377,37 +377,41 @@ int srslte_ue_ul_pusch_encode_cfg(srslte_ue_ul_t *q, srslte_pusch_cfg_t *cfg,
   return ret;   
 }
 
-/* Obtains Scheduling Request channel assignment as defined in Table 10.1-5, 36.213 */
-int srslte_ue_ul_sr_config(uint32_t I_sr, uint32_t *sr_periodicity, uint32_t *sr_N_offset) {
-  if (sr_periodicity && sr_N_offset) {
-    if (I_sr < 5) {
-      *sr_periodicity = 5;
-      *sr_N_offset    = I_sr; 
-    } else if (I_sr < 15) {
-      *sr_periodicity = 10;
-      *sr_N_offset    = I_sr-5;     
-    } else if (I_sr < 35) {
-      *sr_periodicity = 20;
-      *sr_N_offset    = I_sr-15; 
-    } else if (I_sr < 75) {
-      *sr_periodicity = 40;
-      *sr_N_offset    = I_sr-35; 
-    } else if (I_sr < 155) {
-      *sr_periodicity = 80;
-      *sr_N_offset    = I_sr-75; 
-    } else if (I_sr < 157) {
-      *sr_periodicity = 2;
-      *sr_N_offset    = I_sr-155; 
-    } else if (I_sr == 157) {
-      *sr_periodicity = 1;
-      *sr_N_offset    = I_sr-157; 
-    } else {
-      return SRSLTE_ERROR;
-    }
+/* Returns 1 if a SR needs to be sent at current_tti given I_sr, as defined in Section 10.1 of 36.213 */
+int srslte_ue_ul_sr_send_tti(uint32_t I_sr, uint32_t current_tti) {
+  uint32_t sr_periodicity; 
+  uint32_t sr_N_offset;
+  if (I_sr < 5) {
+    sr_periodicity = 5;
+    sr_N_offset    = I_sr; 
+  } else if (I_sr < 15) {
+    sr_periodicity = 10;
+    sr_N_offset    = I_sr-5;     
+  } else if (I_sr < 35) {
+    sr_periodicity = 20;
+    sr_N_offset    = I_sr-15; 
+  } else if (I_sr < 75) {
+    sr_periodicity = 40;
+    sr_N_offset    = I_sr-35; 
+  } else if (I_sr < 155) {
+    sr_periodicity = 80;
+    sr_N_offset    = I_sr-75; 
+  } else if (I_sr < 157) {
+    sr_periodicity = 2;
+    sr_N_offset    = I_sr-155; 
+  } else if (I_sr == 157) {
+    sr_periodicity = 1;
+    sr_N_offset    = I_sr-157; 
+  } else {
+    return SRSLTE_ERROR;
+  }
+  uint32_t sfn = current_tti/10;
+  uint32_t subf = current_tti%10; 
+  if ((10*sfn+subf-sr_N_offset)%sr_periodicity==0) {
+    return 1; 
   } else {
-    return SRSLTE_ERROR_INVALID_INPUTS;
+    return SRSLTE_SUCCESS;
   }
-  return SRSLTE_SUCCESS;
 }