ZTE MF75 - Manual (Page 23)

MobiiConnect 4G Manual 23
Settings > Device settings > Power Save
You can adjust the Power Saving settings on this page.
By default, Wi-Fi Performance is set to Long Range Wi-Fi. This provides the best Wi-Fi coverage and data speeds,
but it does use more power.
If the device that MobiiConnect 4G is plugged in to is connected to an electrical outlet or another non-battery
power source, there should be no need to adjust this setting.
If you are using a laptop on batteries, you may wish to change the Wi-Fi Performance to Short or Medium Range.
Short Wi-Fi Range will provide the best power saving, but you will experience a shorter Wi-Fi range and slower
data speeds over distance.