Turn off WiFi power saving mode in Raspberry Pi

By default, some wireless adapters enable “Power Saving”. This is a “sleep mode”, or rather an energy-saving feature. This means that the adapter will turn off the network connection when inactive. This is not a problem when using Raspberry Pi as a client. Then the WiFi connection is simply reactivated. But if you want to remotely access Raspberry Pi via SSH for example, it may not be accessible. Then it looks like the WiFi adapter is not working. Only the energy saving function is active.
So it is necessary to turn off the power saving function.

For each wireless adapter, switching off the power saving function looks different. As a rule, the energy-saving function is always active. If you have problems reaching Raspberry Pi via the WiFi adapter you should first locate the manufacturer, if you do not already know that. Often, however, one also has to do with noname products.

• Determine information about the WiFi adapter
• Use raspberry pi as a WiFi router