How to setup and fix problem when you connecting 3G USB Modem on Wireless Router TP-Link and stuck in state of identifying 3G/4G USB Modem by upgrading the firmware of the router. In this case I am using Wireless Router TP-Link TL-MR3420 series as the access point (AP). The Usb modem is Huawei 3G USB modem with the ISP is three/3 AON. By upgrading the firmware wireless router can be fix any bug when connecting or identifying 3G/4G USB Modem on wireless router.