Call failed error while connecting the cellular network

[jyijyi]

I would suggest you try the latest FW and first test with AT!SCACT.

Example on establishing data connection by AT!SCACT via MBPL R20 driver

Here is an example to establish data connection by AT!SCACT via MBPL R20 driver: Module: WP7609 FW: R13 MBPL: R20 PC Environment: Ubuntu 18 need to install the MBPL R20 driver for qmi_wwan and qcserial (MBPL_Drivers_USB_R20_ENG1-src.tar.gz) avoid the Ubuntu changing the network name: ln -s /dev/null /etc/systemd/network/99-default.link sudo apt-get install libqmi-utils sudo apt-get install udhcpc now insert the USB to PC sudo chmod 777 /sys/class/net/wwan0/qmi/raw_ip …

Latest Firmware:

https://source.sierrawireless.com/resources/airprime/minicard/75xx/em_mc75xx-approved-fw-packages/#sthash.YXVh7SsM.dpbs