diff --git a/srsenb/hdr/upper/pdcp.h b/srsenb/hdr/upper/pdcp.h
index c249b856e..37f473117 100644
--- a/srsenb/hdr/upper/pdcp.h
+++ b/srsenb/hdr/upper/pdcp.h
@@ -41,6 +41,7 @@ class pdcp :  public pdcp_interface_rlc,
 public:
  
   void init(rlc_interface_pdcp *rlc_, rrc_interface_pdcp *rrc_, gtpu_interface_pdcp *gtpu_, srslte::log *pdcp_log_);
+  ~pdcp();
   void stop(); 
   
   // pdcp_interface_rlc
@@ -103,7 +104,10 @@ private:
     user_interface_gtpu gtpu_itf;
     user_interface_rrc  rrc_itf; 
     srslte::pdcp        *pdcp; 
-  }; 
+  };
+
+  // Mutex to protect access to users std::map
+  pthread_mutex_t mutex;
   
   std::map<uint32_t,user_interface> users; 
   
diff --git a/srsenb/hdr/upper/rlc.h b/srsenb/hdr/upper/rlc.h
index 2b0752cf1..92911df70 100644
--- a/srsenb/hdr/upper/rlc.h
+++ b/srsenb/hdr/upper/rlc.h
@@ -49,6 +49,7 @@ public:
  
   void init(pdcp_interface_rlc *pdcp_, rrc_interface_rlc *rrc_, mac_interface_rlc *mac_, 
             srslte::mac_interface_timers *mac_timers_, srslte::log *log_h);
+  ~rlc();
   void stop(); 
   
   // rlc_interface_rrc
@@ -91,11 +92,13 @@ private:
     srsenb::rrc_interface_rlc  *rrc;
     srslte::rlc                *rlc; 
     srsenb::rlc                *parent; 
-  }; 
-  
+  };
+
+  // Mutex to protect access to users std::map
+  pthread_mutex_t mutex;
+
   std::map<uint32_t,user_interface> users; 
-  std::vector<mch_service_t> mch_services;
-  
+
   mac_interface_rlc             *mac; 
   pdcp_interface_rlc            *pdcp;
   rrc_interface_rlc             *rrc;
diff --git a/srsenb/src/upper/pdcp.cc b/srsenb/src/upper/pdcp.cc
index e6f4f40f5..a8774e408 100644
--- a/srsenb/src/upper/pdcp.cc
+++ b/srsenb/src/upper/pdcp.cc
@@ -37,6 +37,11 @@ void pdcp::init(rlc_interface_pdcp* rlc_, rrc_interface_pdcp* rrc_, gtpu_interfa
   log_h = pdcp_log_;
   
   pool = srslte::byte_buffer_pool::get_instance();
+  pthread_mutex_init(&mutex, NULL);
+}
+
+pdcp::~pdcp() {
+  pthread_mutex_destroy(&mutex);
 }
 
 void pdcp::stop()
@@ -44,11 +49,14 @@ void pdcp::stop()
   for(std::map<uint32_t, user_interface>::iterator iter=users.begin(); iter!=users.end(); ++iter) {
     rem_user((uint32_t) iter->first);
   }
+  pthread_mutex_lock(&mutex);
   users.clear();
+  pthread_mutex_unlock(&mutex);
 }
 
 void pdcp::add_user(uint16_t rnti)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti) == 0) {
     srslte::pdcp *obj = new srslte::pdcp;     
     obj->init(&users[rnti].rlc_itf, &users[rnti].rrc_itf, &users[rnti].gtpu_itf, log_h, RB_ID_SRB0, SECURITY_DIRECTION_DOWNLINK);
@@ -61,20 +69,24 @@ void pdcp::add_user(uint16_t rnti)
     users[rnti].gtpu_itf.gtpu = gtpu;
     users[rnti].pdcp = obj;
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void pdcp::rem_user(uint16_t rnti)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].pdcp->stop();
     delete users[rnti].pdcp; 
     users[rnti].pdcp = NULL;
     users.erase(rnti);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void pdcp::add_bearer(uint16_t rnti, uint32_t lcid, srslte::srslte_pdcp_config_t cfg)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     if(rnti != SRSLTE_MRNTI){
       users[rnti].pdcp->add_bearer(lcid, cfg);
@@ -82,37 +94,45 @@ void pdcp::add_bearer(uint16_t rnti, uint32_t lcid, srslte::srslte_pdcp_config_t
       users[rnti].pdcp->add_bearer_mrb(lcid, cfg);
     }
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void pdcp::reset(uint16_t rnti)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].pdcp->reset();
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void pdcp::config_security(uint16_t rnti, uint32_t lcid, uint8_t* k_rrc_enc_, uint8_t* k_rrc_int_, 
                            srslte::CIPHERING_ALGORITHM_ID_ENUM cipher_algo_, 
                            srslte::INTEGRITY_ALGORITHM_ID_ENUM integ_algo_)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].pdcp->config_security(lcid, k_rrc_enc_, k_rrc_int_, cipher_algo_, integ_algo_);
     users[rnti].pdcp->enable_integrity(lcid);
     users[rnti].pdcp->enable_encryption(lcid);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void pdcp::write_pdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].pdcp->write_pdu(lcid, sdu);
   } else {
     pool->deallocate(sdu);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void pdcp::write_sdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     if(rnti != SRSLTE_MRNTI){
       users[rnti].pdcp->write_sdu(lcid, sdu);
@@ -122,6 +142,7 @@ void pdcp::write_sdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
   } else {
     pool->deallocate(sdu);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void pdcp::user_interface_gtpu::write_pdu(uint32_t lcid, srslte::byte_buffer_t *pdu)
diff --git a/srsenb/src/upper/rlc.cc b/srsenb/src/upper/rlc.cc
index 0624dbca4..d9860b475 100644
--- a/srsenb/src/upper/rlc.cc
+++ b/srsenb/src/upper/rlc.cc
@@ -40,6 +40,11 @@ void rlc::init(pdcp_interface_rlc* pdcp_, rrc_interface_rlc* rrc_, mac_interface
 
   pool       = srslte::byte_buffer_pool::get_instance();
 
+  pthread_mutex_init(&mutex, NULL);
+}
+
+rlc::~rlc() {
+  pthread_mutex_destroy(&mutex);
 }
 
 void rlc::stop()
@@ -47,12 +52,15 @@ void rlc::stop()
   for(std::map<uint32_t, user_interface>::iterator iter=users.begin(); iter!=users.end(); ++iter) {
     rem_user((uint32_t) iter->first);
   }
+  pthread_mutex_lock(&mutex);
   users.clear();
+  pthread_mutex_unlock(&mutex);
 }
 
 void rlc::add_user(uint16_t rnti)
 {
-  if (users.count(rnti) == 0) {    
+  pthread_mutex_lock(&mutex);
+  if (users.count(rnti) == 0) {
     srslte::rlc *obj = new srslte::rlc;     
     obj->init(&users[rnti], &users[rnti], &users[rnti], log_h, mac_timers, RB_ID_SRB0);
     users[rnti].rnti   = rnti; 
@@ -61,27 +69,33 @@ void rlc::add_user(uint16_t rnti)
     users[rnti].rlc    = obj;
     users[rnti].parent = this; 
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void rlc::rem_user(uint16_t rnti)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].rlc->stop();
     delete users[rnti].rlc; 
     users[rnti].rlc = NULL;
     users.erase(rnti);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void rlc::reset(uint16_t rnti)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].rlc->reset();
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void rlc::clear_buffer(uint16_t rnti)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].rlc->empty_queue();
     for (int i=0;i<SRSLTE_N_RADIO_BEARERS;i++) {
@@ -89,27 +103,34 @@ void rlc::clear_buffer(uint16_t rnti)
     }
     log_h->info("Cleared buffer rnti=0x%x\n", rnti);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void rlc::add_bearer(uint16_t rnti, uint32_t lcid)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].rlc->add_bearer(lcid);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void rlc::add_bearer(uint16_t rnti, uint32_t lcid, srslte::srslte_rlc_config_t cnfg)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].rlc->add_bearer(lcid, cnfg);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void rlc::add_bearer_mrb(uint16_t rnti, uint32_t lcid)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].rlc->add_bearer_mrb_enb(lcid);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void rlc::read_pdu_pcch(uint8_t* payload, uint32_t buffer_size)
@@ -119,13 +140,14 @@ void rlc::read_pdu_pcch(uint8_t* payload, uint32_t buffer_size)
 
 int rlc::read_pdu(uint16_t rnti, uint32_t lcid, uint8_t* payload, uint32_t nof_bytes)
 {
+  pthread_mutex_lock(&mutex);
   int ret;
   uint32_t tx_queue;
-  if(users.count(rnti)){
-    if(rnti != SRSLTE_MRNTI){
+  if (users.count(rnti)) {
+    if (rnti != SRSLTE_MRNTI) {
       ret = users[rnti].rlc->read_pdu(lcid, payload, nof_bytes);
       tx_queue = users[rnti].rlc->get_total_buffer_state(lcid);
-    }else{
+    } else {
       ret = users[rnti].rlc->read_pdu_mch(lcid, payload, nof_bytes);
       tx_queue = users[rnti].rlc->get_total_mch_buffer_state(lcid);
     }
@@ -135,15 +157,14 @@ int rlc::read_pdu(uint16_t rnti, uint32_t lcid, uint8_t* payload, uint32_t nof_b
     uint32_t retx_queue = 0;
     log_h->debug("Buffer state PDCP: rnti=0x%x, lcid=%d, tx_queue=%d\n", rnti, lcid, tx_queue);
     mac->rlc_buffer_state(rnti, lcid, tx_queue, retx_queue);
-    return ret;
-    
-  }else{
-    return SRSLTE_ERROR;
   }
+  pthread_mutex_unlock(&mutex);
+  return ret;
 }
 
 void rlc::write_pdu(uint16_t rnti, uint32_t lcid, uint8_t* payload, uint32_t nof_bytes)
 {
+  pthread_mutex_lock(&mutex);
   if (users.count(rnti)) {
     users[rnti].rlc->write_pdu(lcid, payload, nof_bytes);
     
@@ -154,6 +175,7 @@ void rlc::write_pdu(uint16_t rnti, uint32_t lcid, uint8_t* payload, uint32_t nof
     log_h->debug("Buffer state PDCP: rnti=0x%x, lcid=%d, tx_queue=%d\n", rnti, lcid, tx_queue);
     mac->rlc_buffer_state(rnti, lcid, tx_queue, retx_queue);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 void rlc::read_pdu_bcch_dlsch(uint32_t sib_index, uint8_t *payload)
@@ -164,7 +186,8 @@ void rlc::read_pdu_bcch_dlsch(uint32_t sib_index, uint8_t *payload)
 
 void rlc::write_sdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
 {
-  
+
+  pthread_mutex_lock(&mutex);
   uint32_t tx_queue;
   if (users.count(rnti)) {
     if(rnti != SRSLTE_MRNTI){
@@ -183,6 +206,7 @@ void rlc::write_sdu(uint16_t rnti, uint32_t lcid, srslte::byte_buffer_t* sdu)
   } else {
     pool->deallocate(sdu);
   }
+  pthread_mutex_unlock(&mutex);
 }
 
 bool rlc::rb_is_um(uint16_t rnti, uint32_t lcid) {