From e5d07a4231cf2e3841c725af04118f95aac3e211 Mon Sep 17 00:00:00 2001
From: Pedro Alvarez <pedro.alvarez@softwareradiosystems.com>
Date: Thu, 1 Feb 2018 12:54:40 +0000
Subject: [PATCH 1/7] Starting to extract AMF value from authentication request
 (AUTN) in srsUE.

---
 srsue/src/upper/usim.cc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/srsue/src/upper/usim.cc b/srsue/src/upper/usim.cc
index fe70797e3..f8b45d625 100644
--- a/srsue/src/upper/usim.cc
+++ b/srsue/src/upper/usim.cc
@@ -356,6 +356,11 @@ void usim::gen_auth_res_milenage( uint8_t  *rand,
   {
     sqn[i] = autn_enb[i] ^ ak[i];
   }
+  // Extract AMF from autn
+  for(int i=0;i<2;i++)
+  {
+    amf[i]=autn_enb[6+i];
+  }
 
   // Generate MAC
   security_milenage_f1( k,
@@ -431,6 +436,10 @@ void usim::gen_auth_res_xor(uint8_t  *rand,
   for(i=0;i<6;i++) {
     sqn[i] = autn_enb[i] ^ ak[i];
   }
+  // Extract AMF from autn
+  for(int i=0;i<2;i++){
+      amf[i]=autn_enb[6+i];
+  }
 
   // Generate cdout
   for(i=0; i<6; i++) {

From e4b1525982e72736499ba05fda8875abf5eb4b1e Mon Sep 17 00:00:00 2001
From: Pedro Alvarez <pedro.alvarez@softwareradiosystems.com>
Date: Thu, 1 Feb 2018 14:08:16 +0000
Subject: [PATCH 2/7] Removed AMF from USIM configuration. AMF is exctracted
 from the authentication request now.

---
 srsue/hdr/upper/usim.h        | 1 -
 srsue/src/main.cc             | 1 -
 srsue/src/upper/usim.cc       | 7 -------
 srsue/test/upper/nas_test.cc  | 2 --
 srsue/test/upper/usim_test.cc | 1 -
 srsue/ue.conf.example         | 1 -
 6 files changed, 13 deletions(-)

diff --git a/srsue/hdr/upper/usim.h b/srsue/hdr/upper/usim.h
index cf5a4c820..e37f58218 100644
--- a/srsue/hdr/upper/usim.h
+++ b/srsue/hdr/upper/usim.h
@@ -43,7 +43,6 @@ typedef enum{
 typedef struct{
   std::string algo;
   std::string op;
-  std::string amf;
   std::string imsi;
   std::string imei;
   std::string k;
diff --git a/srsue/src/main.cc b/srsue/src/main.cc
index 98966510c..498aacd54 100644
--- a/srsue/src/main.cc
+++ b/srsue/src/main.cc
@@ -124,7 +124,6 @@ void parse_args(all_args_t *args, int argc, char *argv[]) {
 
     ("usim.algo", bpo::value<string>(&args->usim.algo), "USIM authentication algorithm")
     ("usim.op", bpo::value<string>(&args->usim.op), "USIM operator variant")
-    ("usim.amf", bpo::value<string>(&args->usim.amf), "USIM authentication management field")
     ("usim.imsi", bpo::value<string>(&args->usim.imsi), "USIM IMSI")
     ("usim.imei", bpo::value<string>(&args->usim.imei), "USIM IMEI")
     ("usim.k", bpo::value<string>(&args->usim.k), "USIM K")
diff --git a/srsue/src/upper/usim.cc b/srsue/src/upper/usim.cc
index f8b45d625..b9f4fda0e 100644
--- a/srsue/src/upper/usim.cc
+++ b/srsue/src/upper/usim.cc
@@ -53,13 +53,6 @@ void usim::init(usim_args_t *args, srslte::log *usim_log_)
     usim_log->console("Invalid length for OP: %d should be %d", args->op.length(), 32);
   }
 
-  if(4 == args->amf.length()) {
-    str_to_hex(args->amf, amf);
-  } else {
-    usim_log->error("Invalid length for AMF: %d should be %d", args->amf.length(), 4);
-    usim_log->console("Invalid length for AMF: %d should be %d", args->amf.length(), 4);
-  }
-
   if(15 == args->imsi.length()) {
     imsi = 0;
     for(i=0; i<15; i++)
diff --git a/srsue/test/upper/nas_test.cc b/srsue/test/upper/nas_test.cc
index f328d77df..4f4ffb687 100644
--- a/srsue/test/upper/nas_test.cc
+++ b/srsue/test/upper/nas_test.cc
@@ -117,7 +117,6 @@ int security_command_test()
 
   usim_args_t args;
   args.algo = "xor";
-  args.amf = "9001";
   args.imei = "353490069873319";
   args.imsi = "001010123456789";
   args.k = "00112233445566778899aabbccddeeff";
@@ -179,7 +178,6 @@ int mme_attach_request_test()
   srsue::usim usim;
   usim_args_t args;
   args.algo = "xor";
-  args.amf = "9001";
   args.imei = "353490069873319";
   args.imsi = "001010123456789";
   args.k = "00112233445566778899aabbccddeeff";
diff --git a/srsue/test/upper/usim_test.cc b/srsue/test/upper/usim_test.cc
index 4ac468673..bf60e124c 100644
--- a/srsue/test/upper/usim_test.cc
+++ b/srsue/test/upper/usim_test.cc
@@ -74,7 +74,6 @@ int main(int argc, char **argv)
 
   usim_args_t args;
   args.algo = "milenage";
-  args.amf = "8000";
   args.imei = "35609204079301";
   args.imsi = "208930000000001";
   args.k = "8BAF473F2F8FD09487CCCBD7097C6862";
diff --git a/srsue/ue.conf.example b/srsue/ue.conf.example
index 347822072..140662ac0 100644
--- a/srsue/ue.conf.example
+++ b/srsue/ue.conf.example
@@ -93,7 +93,6 @@ file_max_size = -1
 [usim]
 algo = xor
 op   = 63BFA50EE6523365FF14C1F45F88737D
-amf  = 9001
 k    = 00112233445566778899aabbccddeeff
 imsi = 001010123456789
 imei = 353490069873319

From e2c3a304b7c04d1d06ffa50b2f999712f0018b30 Mon Sep 17 00:00:00 2001
From: Ismael Gomez <ismagom@gmail.com>
Date: Thu, 1 Feb 2018 18:17:40 +0100
Subject: [PATCH 3/7] In-sync and out-of-sync after 100 and 200 ms. Use RSRP
 -124 dBm as per the specs instead of SNR

---
 srsue/hdr/phy/phch_recv.h    |  7 +++++++
 srsue/src/phy/phch_recv.cc   | 20 ++++++++++++++++++--
 srsue/src/phy/phch_worker.cc | 16 +++++++---------
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/srsue/hdr/phy/phch_recv.h b/srsue/hdr/phy/phch_recv.h
index 0530459df..50ea28f96 100644
--- a/srsue/hdr/phy/phch_recv.h
+++ b/srsue/hdr/phy/phch_recv.h
@@ -291,6 +291,13 @@ private:
   // Sync metrics
   sync_metrics_t        metrics;
 
+  // in-sync / out-of-sync counters
+  uint32_t out_of_sync_cnt;
+  uint32_t in_sync_cnt;
+
+  const static uint32_t NOF_OUT_OF_SYNC_SF = 200;
+  const static uint32_t NOF_IN_SYNC_SF     = 100;
+
   // State for primary cell
   enum {
     IDLE = 0,
diff --git a/srsue/src/phy/phch_recv.cc b/srsue/src/phy/phch_recv.cc
index 7d89892c9..de80d53c7 100644
--- a/srsue/src/phy/phch_recv.cc
+++ b/srsue/src/phy/phch_recv.cc
@@ -124,6 +124,8 @@ void phch_recv::stop()
 
 void phch_recv::reset()
 {
+  in_sync_cnt = 0;
+  out_of_sync_cnt = 0;
   tx_mutex_cnt = 0;
   phy_state = IDLE;
   time_adv_sec = 0;
@@ -713,6 +715,7 @@ void phch_recv::run_thread()
               intra_freq_meas.write(tti, buffer[0], SRSLTE_SF_LEN_PRB(cell.nof_prb));
               break;
             case 0:
+              Warning("SYNC:  Out-of-sync detected in PSS/SSS\n");
               out_of_sync();
               worker->release();
               worker_com->reset_ul();
@@ -742,11 +745,24 @@ void phch_recv::run_thread()
 }
 
 void phch_recv::in_sync() {
-  rrc->in_sync();
+  out_of_sync_cnt = 0;
+  in_sync_cnt++;
+  // Send RRC in-sync signal after 100 ms consecutive subframes
+  if (in_sync_cnt == NOF_IN_SYNC_SF) {
+    rrc->in_sync();
+    in_sync_cnt = 0;
+  }
 }
 
+// Out of sync called by worker or phch_recv every 1 or 5 ms
 void phch_recv::out_of_sync() {
-  rrc->out_of_sync();
+  in_sync_cnt = 0;
+  // Send RRC out-of-sync signal after 200 ms consecutive subframes
+  out_of_sync_cnt++;
+  if (out_of_sync_cnt >= NOF_OUT_OF_SYNC_SF) {
+    rrc->out_of_sync();
+    out_of_sync_cnt = 0;
+  }
 }
 
 
diff --git a/srsue/src/phy/phch_worker.cc b/srsue/src/phy/phch_worker.cc
index ebb8710d5..8644beee6 100644
--- a/srsue/src/phy/phch_worker.cc
+++ b/srsue/src/phy/phch_worker.cc
@@ -241,15 +241,12 @@ void phch_worker::work_imp()
   /* Do FFT and extract PDCCH LLR, or quit if no actions are required in this subframe */
   bool chest_ok = extract_fft_and_pdcch_llr();
 
-  bool snr_th_err = 10*log10(srslte_chest_dl_get_snr(&ue_dl.chest))<-20.0;
-  bool snr_th_ok  = 10*log10(srslte_chest_dl_get_snr(&ue_dl.chest))>-15.0;
-
   // Call feedback loop for chest
   if (chest_loop && ((1<<(tti%10)) & phy->args->cfo_ref_mask)) {
     chest_loop->set_cfo(srslte_chest_dl_get_cfo(&ue_dl.chest));
   }
 
-  if (chest_ok && !snr_th_err) {
+  if (chest_ok) {
 
     /***** Downlink Processing *******/
 
@@ -370,12 +367,13 @@ void phch_worker::work_imp()
   update_measurements();
 
   if (chest_ok) {
-    if (snr_th_ok) {
-      log_h->debug("SNR=%.1f dB sync=in-sync from channel estimator\n", 10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)));
+    if (phy->avg_rsrp_dbm > -124.0) {
+      log_h->debug("SNR=%.1f dB, RSRP=%.1f dBm sync=in-sync from channel estimator\n",
+                   10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)), phy->avg_rsrp_dbm);
       chest_loop->in_sync();
-    } else if (snr_th_err) {
-      log_h->info("SNR=%.1f dB sync=out-of-sync from channel estimator\n",
-                   10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)));
+    } else {
+      log_h->warning("SNR=%.1f dB RSRP=%.1f dBm, sync=out-of-sync from channel estimator\n",
+                   10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)), phy->avg_rsrp_dbm);
       chest_loop->out_of_sync();
     }
   }

From 36358fa34bc75a262e94cc5fd78a25b09ad215ae Mon Sep 17 00:00:00 2001
From: Ismael Gomez <ismagom@gmail.com>
Date: Thu, 1 Feb 2018 20:16:10 +0100
Subject: [PATCH 4/7] Use SNR as out-of-sync threshold in addition to RSRP

---
 srsue/src/phy/phch_worker.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/srsue/src/phy/phch_worker.cc b/srsue/src/phy/phch_worker.cc
index 8644beee6..3d051825d 100644
--- a/srsue/src/phy/phch_worker.cc
+++ b/srsue/src/phy/phch_worker.cc
@@ -367,7 +367,7 @@ void phch_worker::work_imp()
   update_measurements();
 
   if (chest_ok) {
-    if (phy->avg_rsrp_dbm > -124.0) {
+    if (phy->avg_rsrp_dbm > -124.0 && 10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)) > -30.0) {
       log_h->debug("SNR=%.1f dB, RSRP=%.1f dBm sync=in-sync from channel estimator\n",
                    10*log10(srslte_chest_dl_get_snr(&ue_dl.chest)), phy->avg_rsrp_dbm);
       chest_loop->in_sync();

From 5eeaf529904aebd5e5d87bc9d87ac48dcf5581f9 Mon Sep 17 00:00:00 2001
From: Ismael Gomez <ismagom@gmail.com>
Date: Thu, 1 Feb 2018 20:16:35 +0100
Subject: [PATCH 5/7] Check for non-zero payload in log

---
 lib/src/common/log_filter.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/src/common/log_filter.cc b/lib/src/common/log_filter.cc
index 6720c21ad..b498d466c 100644
--- a/lib/src/common/log_filter.cc
+++ b/lib/src/common/log_filter.cc
@@ -126,7 +126,7 @@ void log_filter::all_log(srslte::LOG_LEVEL_ENUM level,
       ss << std::endl; 
     }
     
-    if (hex_limit > 0) {
+    if (hex_limit > 0 && hex && size > 0) {
       ss << hex_string(hex, size);
     } 
     str_ptr s_ptr(new std::string(ss.str()));

From 45ea443377891d24f0782604becc6b6e4e8ef507 Mon Sep 17 00:00:00 2001
From: Ismael Gomez <ismagom@gmail.com>
Date: Thu, 1 Feb 2018 20:48:27 +0100
Subject: [PATCH 6/7] Deallocate attach_request pdu

---
 srsue/src/upper/rrc.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/srsue/src/upper/rrc.cc b/srsue/src/upper/rrc.cc
index 84e4bbfd1..f34c80979 100644
--- a/srsue/src/upper/rrc.cc
+++ b/srsue/src/upper/rrc.cc
@@ -958,6 +958,8 @@ void rrc::send_con_setup_complete(byte_buffer_t *nas_msg) {
   memcpy(ul_dcch_msg.msg.rrc_con_setup_complete.dedicated_info_nas.msg, nas_msg->msg, nas_msg->N_bytes);
   ul_dcch_msg.msg.rrc_con_setup_complete.dedicated_info_nas.N_bytes = nas_msg->N_bytes;
 
+  pool->deallocate(nas_msg);
+  
   send_ul_dcch_msg();
 }
 

From 348117df3c298e14b374af437c27a7a4bc5c8a60 Mon Sep 17 00:00:00 2001
From: Ismael Gomez <ismagom@gmail.com>
Date: Fri, 2 Feb 2018 10:58:40 +0100
Subject: [PATCH 7/7] Recover on radio overflow

---
 srsue/hdr/phy/phy.h        | 1 +
 srsue/hdr/ue.h             | 3 ++-
 srsue/hdr/ue_base.h        | 2 ++
 srsue/src/phy/phch_recv.cc | 6 ++++--
 srsue/src/phy/phy.cc       | 5 +++++
 srsue/src/ue.cc            | 7 +++++++
 6 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/srsue/hdr/phy/phy.h b/srsue/hdr/phy/phy.h
index 5a1ac14a7..53d4f6e13 100644
--- a/srsue/hdr/phy/phy.h
+++ b/srsue/hdr/phy/phy.h
@@ -78,6 +78,7 @@ public:
   void set_earfcn(std::vector<uint32_t> earfcns);
   void force_freq(float dl_freq, float ul_freq);
 
+  void radio_overflow();
 
   /********** RRC INTERFACE ********************/
   void    reset();
diff --git a/srsue/hdr/ue.h b/srsue/hdr/ue.h
index b008b2fd5..763531261 100644
--- a/srsue/hdr/ue.h
+++ b/srsue/hdr/ue.h
@@ -73,13 +73,14 @@ public:
   void start_plot();
 
   static void rf_msg(srslte_rf_error_t error);
-  void handle_rf_msg(srslte_rf_error_t error);
 
   // UE metrics interface
   bool get_metrics(ue_metrics_t &m);
 
   void pregenerate_signals(bool enable);
 
+  void radio_overflow();
+
 private:
   virtual ~ue();
 
diff --git a/srsue/hdr/ue_base.h b/srsue/hdr/ue_base.h
index 9674a1486..256813d5f 100644
--- a/srsue/hdr/ue_base.h
+++ b/srsue/hdr/ue_base.h
@@ -156,6 +156,8 @@ public:
   virtual void stop() = 0;
   virtual bool is_attached() = 0;
   virtual void start_plot() = 0;
+
+  virtual void radio_overflow() = 0;
   
   void handle_rf_msg(srslte_rf_error_t error);
 
diff --git a/srsue/src/phy/phch_recv.cc b/srsue/src/phy/phch_recv.cc
index de80d53c7..944a6e955 100644
--- a/srsue/src/phy/phch_recv.cc
+++ b/srsue/src/phy/phch_recv.cc
@@ -296,15 +296,17 @@ bool phch_recv::stop_sync() {
       usleep(10000);
       cnt++;
     }
+    if (!is_in_idle) {
+      Warning("SYNC:  Could not go to IDLE\n");
+    }
     return is_in_idle;
   }
 }
 
 void phch_recv::reset_sync() {
 
-  wait_radio_reset();
-
   Warning("SYNC:  Resetting sync, cell_search_in_progress=%s\n", cell_search_in_progress?"yes":"no");
+
   search_p.reset();
   srslte_ue_sync_reset(&ue_sync);
   resync_sfn(true, true);
diff --git a/srsue/src/phy/phy.cc b/srsue/src/phy/phy.cc
index 0763b09cb..820cf1351 100644
--- a/srsue/src/phy/phy.cc
+++ b/srsue/src/phy/phy.cc
@@ -352,6 +352,11 @@ int phy::prach_tx_tti()
   return prach_buffer.tx_tti();
 }
 
+// Handle the case of a radio overflow. Resynchronise inmediatly
+void phy::radio_overflow() {
+  sf_recv.reset_sync();
+}
+
 void phy::reset()
 {
   Info("Resetting PHY\n");
diff --git a/srsue/src/ue.cc b/srsue/src/ue.cc
index 184cbcf56..a9277e62c 100644
--- a/srsue/src/ue.cc
+++ b/srsue/src/ue.cc
@@ -297,10 +297,17 @@ bool ue::get_metrics(ue_metrics_t &m)
   return false;
 }
 
+void ue::radio_overflow() {
+  phy.radio_overflow();
+}
+
 void ue::rf_msg(srslte_rf_error_t error)
 {
   ue_base *ue = ue_base::get_instance(LTE);
   ue->handle_rf_msg(error);
+  if(error.type == srslte_rf_error_t::SRSLTE_RF_ERROR_OVERFLOW) {
+    ue->radio_overflow();
+  }
 }
 
 } // namespace srsue