Low-Power Wi-Fi

One of the most important directions in the development of Wi-Fi technology is energy efficiency. This is largely due to the fact that user devices, such as smartphones, tablets, and laptops, are portable and therefore need to be energy-independent while using wireless technologies for data transmission. Despite this, the development and widespread adoption of Internet of Things (IoT) technologies have led to new scenarios where the key requirement for devices is ultra-low power consumption, meaning the ability to operate for years on a single battery charge.

To adapt Wi-Fi technology to such scenarios, modern power-saving mechanisms have been developed, such as the Target Wake Time (TWT) mechanism and the additional low-power Wake-Up Radio (WUR) interface. Both mechanisms are based on the same principle: they allow devices to enter a “sleep mode” to save energy and “wake up” only for data transmission. However, TWT schedules and coordinates service intervals with devices, whereas WUR uses a special signal sent via the additional radio interface to trigger “wake-ups.”

The Laboratory team actively studies these mechanisms, addressing the challenge of maintaining quality of service for devices in heterogeneous networks, where devices with different requirements for throughput, latency, and power consumption operate simultaneously. Analytical and simulation models have been developed to evaluate the performance of TWT and WUR in various scenarios, enabling the assessment of key metrics for sensor networks, such as the proportion of channel time used and the average energy consumption of sensors. Based on these models, practical recommendations have been formulated for configuring TWT and WUR parameters, as well as for choosing between the two mechanisms depending on the scenario. These recommendations help manufacturers improve the efficiency of real-world networks.

The Laboratory closely follows the development of standards. In 2025, the new IEEE 802.11be standard, known as Wi-Fi 7, was released, introducing an enhancement to the TWT mechanism—the Restricted TWT (R-TWT). R-TWT allows an access point not only to assign wake-up intervals to sensors but also to prevent any device from overlapping the start of these intervals. In theory, this can enable faster data transmission to sensors with lower energy consumption. In practice, achieving improved performance requires careful configuration of R-TWT parameters. To find optimal settings, the Laboratory team is developing analytical and simulation models that account for different traffic types and intensities. The current research, supported by the RNF grant, aims to extend these models to more general and complex scenarios for sensor network operation.