Overview

Similar to many other technologies designed for low-power applications, Wi-Fi incorporates various power-saving modes to reduce power consumption in devices, thereby extending their battery lifetime. In this lesson, we will explore the power-saving modes employed by Nordic’s nRF70 Series devices, understanding their functionality and the corresponding APIs available for their implementation. Before we delve into the power-saving modes, we will introduce some key concepts that provide context to understand the differences between the power-saving modes.

In the exercise section of this lesson, we will use Wi-Fi power save modes to reduce the power consumption of the device and inspect how different power save wake-up modes affect the power consumption using a Power Profiler Kit II. In the last exercise, we will practice using Target Wake Time in an application, including the TWT sleep status notification feature.

Objectives

• Learn about beacon frames, Delivery Traffic Indication Message (DTIM), and message retrieval, both in broadcast/multicast and unicast cases.
• Understand the different power-saving modes available in legacy Wi-Fi.
• Learn about the TWT power save mode and relevant use cases.
• Examine the necessary API’s to enable and configure power save modes.
• Practice through hands-on exercises how to enable power save modes in your application and measure the power consumption.

Special hardware requirements

• Wi-Fi 6 Access Point with Target Wake Time support (only for exercise 2)
• Power Profiler Kit II