diff --git a/src/configure_modem.sh b/src/configure_modem.sh
index bc72afd..3975f81 100644
--- a/src/configure_modem.sh
+++ b/src/configure_modem.sh
@@ -7,6 +7,9 @@ STATUS=${STATUS_PIN:-23}
 POWERKEY=${POWERKEY_PIN:-24}
 POWER_UP_REQUIRED=${POWERUP_FLAG:-1}
 
+# default arguments
+APN=${SIM_APN:-super}
+
 # 1 : STATUS
 # 2 : POWERKEY 
 function power_up_module
@@ -23,7 +26,7 @@ function power_up_module
 			gpio -g write $POWERKEY 1
 			sleep 2
 			gpio -g write $POWERKEY 0
-			sleep 2
+			sleep 5
 
 			if [[ $(gpio -g read $STATUS) -eq 0 ]]; then
 				debug "Module is powered up."
@@ -42,14 +45,6 @@ function power_up_module
 	return 1 
 }
 
-# Check the vendor
-lsusb | grep Quectel >> /dev/null
-IS_QUECTEL=$?
-
-lsusb | grep Telit >> /dev/null
-IS_TELIT=$?
-
-
 if [[ $POWER_UP_REQUIRED -eq 1 ]]; then
     if power_up_module -eq 0 ; then sleep 0.1; else debug "Module couldn't be powered up! Check the hardware setup!"; fi
 else 
@@ -61,13 +56,20 @@ debug "Checking APN and Modem Mode..."
 
 # APN Configuration
 # -----------------
-atcom "AT+CGDCONT?" | grep super >> /dev/null
+atcom "AT+CGDCONT?" | grep $APN > /dev/null
 
 if [[ $? -ne 0 ]]; then
-    atcom "AT+CGDCONT=1,\"IPV4V6\",\"super\""
+    atcom "AT+CGDCONT=1,\"IPV4V6\",\"$APN\""
     debug "APN is updated."
 fi
 
+# Check the vendor
+lsusb | grep Quectel >> /dev/null
+IS_QUECTEL=$?
+
+lsusb | grep Telit >> /dev/null
+IS_TELIT=$?
+
 # Modem Mode Configuration
 # ------------------------
 # For Quectel
@@ -80,7 +82,7 @@ if [[ $IS_QUECTEL -eq 0 ]]; then
         # BG95 and BG96
 
         # RAT Searching Sequence
-        atcom "AT+QCFG=\"nwscanseq\"" | grep 000201 >> /dev/null
+        atcom "AT+QCFG=\"nwscanseq\"" | grep 020301 > /dev/null
 
         if [[ $? -ne 0 ]]; then
             atcom "AT+QCFG=\"nwscanseq\",00"
@@ -88,7 +90,7 @@ if [[ $IS_QUECTEL -eq 0 ]]; then
         fi
 
         # RAT(s) to be Searched
-        atcom "AT+QCFG=\"nwscanmode\"" | grep 0 >> /dev/null
+        atcom "AT+QCFG=\"nwscanmode\"" | grep 0 > /dev/null
 
         if [[ $? -ne 0 ]]; then
             atcom "AT+QCFG=\"nwscanmode\",0"
@@ -96,7 +98,7 @@ if [[ $IS_QUECTEL -eq 0 ]]; then
         fi
 
         # Network Category to be Searched under LTE RAT
-        atcom "AT+QCFG=\"iotopmode\"" | grep 0 >> /dev/null
+        atcom "AT+QCFG=\"iotopmode\"" | grep 0 > /dev/null
 
         if [[ $? -ne 0 ]]; then
             atcom "AT+QCFG=\"iotopmode\",0"
@@ -106,7 +108,7 @@ if [[ $IS_QUECTEL -eq 0 ]]; then
         # end of configuraiton for BG95/6
     else
         # EC25 or derives.
-        atcom "AT+QCFG=\"usbnet\"" | grep 0 >> /dev/null
+        atcom "AT+QCFG=\"usbnet\"" | grep 0 > /dev/null
 
         if [[ $? -ne 0 ]]; then
             atcom "AT+QCFG=\"usbnet\",0"
@@ -170,7 +172,7 @@ else
     debug "The cellular module couldn't be detected!"
     exit 1
 fi
-### End of Modem configuration for ECM mode ############################
+### End of Modem configuration for RMNET/PPP mode ############################
 
 
 # Check the network is ready
diff --git a/src/functions.sh b/src/functions.sh
index 6bf19b1..8f4c418 100644
--- a/src/functions.sh
+++ b/src/functions.sh
@@ -24,29 +24,35 @@ function check_network()
     for i in {1..$NETWORK_CHECK_TIMEOUT}; do
         NETWORK_OK=0
 
-        debug "SIM Status:"
+        debug "SIM Status: " "-n" # no line break
         atcom AT+CPIN? | grep "CPIN: READY"
         SIM_READY=$?
 
-        debug "Network Registeration Status:"
+        if [[ $SIM_READY -ne 0 ]]; then  atcom AT+CPIN? | grep "CPIN:"; fi
+
+
+        debug "Network Registeration Status: " "-n" # no line break
         # For super SIM
-        atcom AT+CREG? | grep "CREG: 0,5"
+        atcom AT+CREG? | grep "CREG: 0,5" > /dev/null
         NETWORK_REG=$?
         # For native SIM
-        atcom AT+CREG? | grep "CREG: 0,1"
+        atcom AT+CREG? | grep "CREG: 0,1" > /dev/null
         NETWORK_REG_2=$?
         # Combined network registeration status
         NETWORK_REG=$((NETWORK_REG+NETWORK_REG_2))
 
+        if [[ $NETWORK_REG -ne 0 ]] || [[ $NETWORK_REG_2 -ne 0 ]]; then  atcom AT+CREG? | grep "CREG:"; fi
+
         if [[ $SIM_READY -eq 0 ]] && [[ $NETWORK_REG -le 1 ]]; then
             debug "Network is ready."
             NETWORK_OK=1
             return 0
             break
         else
-            printf "?"
+            debug "Retrying network registeration..."
         fi
         sleep 2
     done
+    debug "Retwork registeration is failed! Please check SIM card, data plan, antennas etc."
     return 1
 }