Add: better way to restart cell network

misc/get_pgns.sh

@@ -3,8 +3,13 @@
 curl -o /opt/tmp_pgns http://cloudradio39.ecn.purdue.edu/pgns -m 30 > /dev/null 2>&1
 
 if [ $? != 0 ]; then
-	echo 'curl failed, check network status'
-  udevadm trigger && echo 'try retriggering udev to setup Internet ...'
+	echo 'curl failed, check network status!'
+	PROCESS_NUM=$(ps -ef | grep "dhclient" | grep -v "grep" | wc -l)
+	if [ $PROCESS_NUM -eq 0 ]; then
+		echo 'network is down, and no dhclient running ... will try restarting the cell network'
+		qmicli -p -d /dev/cdc-wdm0 --wds-start-network=Broadband --client-no-release-cid
+		dhclient wwan0
+	fi
 	exit 1
 fi