A method of upgrading firmware by configuring a low data-rate radio frequency (RF) module using high frequency RF bands utilizes at least one remote server, a mobile device, and at least one end device. The end device includes at least one activation module, a high data-rate RF module, and a microcontroller. The mobile device includes a large configuration file for upgrading the firmware and changing the configuration settings of the end device. The activation module sends a power-up command to the microcontroller for activating the high data-rate RF module. Accordingly, the high data-rate RF module forms a connection with the mobile device, whereby the mobile device sends the large configuration file to the end device. The end device executes a firmware upgrade and modifies configuration in accordance with the large configuration file.