L3 RRC/NAS developments

src/ue/nas/mm/base.cpp

@@ -165,7 +165,7 @@ void NasMm::performMmCycle()
     /* Try to start procedures */
     invokeProcedures();
 
-    /* Initial registration controls */
+    /* Registration related */
     if (m_mmSubState == EMmSubState::MM_DEREGISTERED_NORMAL_SERVICE && !m_timers->t3346.isRunning())
         initialRegistrationRequired(EInitialRegCause::MM_DEREG_NORMAL_SERVICE);
     else if (m_mmSubState == EMmSubState::MM_DEREGISTERED_NORMAL_SERVICE && hasEmergency())
@@ -180,6 +180,16 @@ void NasMm::performMmCycle()
             initialRegistrationRequired(EInitialRegCause::EMERGENCY_SERVICES);
     }
 
+    if (m_mmSubState == EMmSubState::MM_REGISTERED_ATTEMPTING_REGISTRATION_UPDATE && hasEmergency())
+    {
+        // 5.2.3.2.3; f)
+        // "may perform de-registration locally and initiate a registration procedure for initial registration for
+        // emergency services even if timer T3346 is running"
+
+        // UE will try to send initial emergency registration after local de-registration
+        performLocalDeregistration();
+    }
+
     /* Process TAI changes if any */
     if (currentTai.hasValue() &&
         !nas::utils::TaiListContains(m_storage->taiList->get(), nas::VTrackingAreaIdentity{currentTai}))

src/ue/nas/mm/dereg.cpp

@@ -28,6 +28,10 @@ static nas::IEDeRegistrationType MakeDeRegistrationType(EDeregCause deregCause)
 
 EProcRc NasMm::sendDeregistration(EDeregCause deregCause)
 {
+    auto currentTai = m_base->shCtx.getCurrentTai();
+    if (!currentTai.hasValue())
+        return EProcRc::STAY;
+
     if (m_rmState != ERmState::RM_REGISTERED)
     {
         m_logger->warn("De-registration could not be triggered. UE is already de-registered");
@@ -37,6 +41,17 @@ EProcRc NasMm::sendDeregistration(EDeregCause deregCause)
     if (m_mmState == EMmState::MM_DEREGISTERED_INITIATED)
         return EProcRc::CANCEL;
 
+    // 5.2.3.2.3 "shall not initiate de-registration procedure unless timer T3346 is running and the current TAI is part
+    // of the TAI list."
+    if (m_mmSubState == EMmSubState::MM_REGISTERED_ATTEMPTING_REGISTRATION_UPDATE)
+    {
+        if (!m_timers->t3346.isRunning() ||
+            !nas::utils::TaiListContains(m_storage->taiList->get(), nas::VTrackingAreaIdentity{currentTai}))
+        {
+            return EProcRc::STAY;
+        }
+    }
+
     m_logger->debug("Starting de-registration procedure due to [%s]", ToJson(deregCause).str().c_str());
 
     updateProvidedGuti();
@@ -330,9 +345,6 @@ void NasMm::receiveDeregistrationRequest(const nas::DeRegistrationRequestUeTermi
 
 void NasMm::performLocalDeregistration()
 {
-    if (m_mmState == EMmState::MM_DEREGISTERED)
-        return;
-
     m_logger->debug("Performing local de-registration");
 
     m_timers->t3521.stop();