Control Wlan Power Management under Linux with iw

iw, the command line tool, enables various configuration opportunities for wireless devices. Since Power Management regarding transmission/reception power is problematic with some cards, you can disable it under Linux. This article shows how to install and use the tool under Ubuntu or Debian as well as Red Hat Enterprise Linux. Normally, the tool is already preinstalled in most distributions.

Installation of iw

Use the package manager to perform the installation from the repositories, so that iw can be used.

• Ubuntu / Debian based systems: $ sudo apt install iw
• RHEL / CentOS: # yum install iw

Usage of iw

After the installation has been successful, iw is executed as root in the terminal and can be called up with further parameters.

The tool also offers multiple opportunities to configure available WLAN adapters:

• Power Management control
• Transmission power control
• Output of hardware characteristics
• Output Hardware properties of the WLAN device
• Scan neighboring Wi-Fi networks for signal strength (reception quality)/transmission rate and encryption method used.

Examples

In the following, you will find some examples for the usage of iw:

• Call up latest WLAN interfaces:

# iw dev

• Current Device Capabilities of the WLAN devices:

# iw list

• Finish Power Management (Problem: bad transmit/receive power):

# iw dev wlan0 set power_save off

• Call up current Power Management state:

# if dev wlan0 get power_save

Power Management in connection with NetworkManager

As the setting gets lost during a reboot, it is recommended to enter the settings in the /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf file permanently. For example, the value "2" stands for Power Management "Off".

Add the following entry to default-wifi-powersave-on.conf:

[connection]

wifi.powersave = 2

References

Author: Wilfried Seifert Wilfried Seifert, working in the Systems Engineering department at Thomas-Krenn, is responsible for system/prototype development in his work area. LPIC 3 certified, deals with construction / programming of embedded / GPIO systems; in his spare time he likes to repair old home computers, attends Linux conferences or is on the road with his bike (MTB) for sporting compensation.

Translator: Alina Ranzinger Alina has been working at Thomas-Krenn.AG since 2024. After her training as multilingual business assistant, she got her job as assistant of the Product Management and is responsible for the translation of texts and for the organisation of the department.