Updating procedure huawei e220
I used dc-unlocker to check for information needed later on the steps.
You can download the firmware from several sources.
The Huawei E220 is a Huawei HSDPA access device (modem) manufactured by Huawei and notable for using the USB interface (USB modem).
The procedure below has been tested on only ONE Huawei E1550 3G modem.The long one has two USB A interfaces, one used for data and power and the other optionally only for assistance power in case the computer is not able to provide the full 500 m A (milliamperes) required for the device to work from one USB interface only.