Extract Huawei E3531s Firmware 22.318.31.00.666 on your computer
Install the Firmware update file for Huawei E3531s downloaded from Huaweiflashfiles.com
Follow the procedure for updating Firmware that is given in Package.

Huawei Flash File | Size: 16.64 MB
Version: 22.318.31.00.666
Operator:Universal
Operating systems: Windows 7/8/10/XP/Vista
Huawei E3531s Firmware Download