Wi-Fi HaLow offers promising capabilities for handling heterogeneous traffic in Internet of Things environments through its high throughput and built-in scheduled access mechanisms, including Restricted Access Window (RAW) and Target Wake Time (TWT), which save energy and avoid collisions. However, most existing devices do not support such mechanisms, which significantly limits the performance of Wi-Fi HaLow networks. An alternative solution is to implement software-based scheduled access at the application level, i.e., make an application responsible for scheduled data transmission. Correct operation of software-based scheduling requires knowledge of possible latencies caused by data processing and Medium Access Control (MAC) layer random access mechanisms. In this paper, we tackle this problem and study latencies for the Software-Based RAW (SB-RAW) mechanism for scheduled data transmissions. Based on that, we estimate the minimum guard interval between scheduled transmissions using Wi-Fi HaLow devices. Our findings provide practical guidelines for SB-RAW usage in Wi-Fi HaLow networks, particularly for applications with various traffic requirements.

New data transmission methods are needed for future Wi-Fi networks to increase throughput and support dense deployments. Wi-Fi networks often consist of devices of different generations, so these methods need to support backward compatibility. Uplink non-orthogonal multiple access (UL-NOMA) is one of the promising methods to address this problem. UL-NOMA increases the spectral efficiency of wireless networks by separating signals by power. However, only a few papers study UL-NOMA in Wi-Fi analytically or with simulations. This demo presents a prototype of a UL-NOMA Wi-Fi communication system and discusses how to implement successive interference cancellation in a UL-NOMA receiver taking into account Wi-Fi limitations.

Non-orthogonal multiple access (NOMA) is a well-accepted technology for future Wi-Fi systems to improve spectral efficiency. NOMA allows an access point (AP) to simultaneously serve multiple devices by splitting the transmit power between them. Using the superposition coding the AP combines signals of different frames with predefined power weights. However, as it is already known, the phase noise caused by hardware imperfections limits the performance of NOMA transmissions. The paper proposes a practical, easy-to-implement, and backward-compatible method to rotate the constellation of the low power signal in order to make it more robust to the phase noise. A mathematical model is developed to find such a rotation angle that minimizes the bit error rate (BER) of the low power frame. A new NOMA Wi-Fi prototype testbed is developed with the new feature of constellation rotation ability, which is used to validate the performance of our proposed method. Many experimental results show the proposed constellation rotation approach significantly decreases the BER in high signal-to-noise scenarios.

Non-Orthogonal Multiple Access (NOMA) is currently considering as a promising technology for increasing the network efficiency in heterogeneous scenarios with different types of traffic and interference conditions. In spite of numerous theoretical works, there are few experimental studies of NOMA, most of which consider cellular networks. In this short paper, we present our pioneering NOMA testbed for Wi-Fi networks. Because the Wi-Fi technology is much simpler and cheaper than the cellular ones, we expect that the testbed can be used by the research community to validate various solutions designed for NOMA in real equipment.

In order to meet the rising demands for the Internet of Things technologies, Wi-Fi community has developed Wi-Fi HaLow. It extends Wi-Fi with new functionality supporting high number of autonomous devices with various power capabilities and traffic patterns. In the paper, we study the cooperation of such new mechanisms as TIM Segmentation and Restricted Access Window. TIM Segmentation reduces energy consumption for low-power devices retrieving data from the Access Point, while Restricted Access Window reduces contention and allows the Access Point to protect stations with different capabilities from interfering each other. We consider joint usage of these mechanisms in a heterogeneous network with a high number of low-power stations with rare traffic and several powered stations with saturated traffic. Specifically, for TIM Segmentation and Restricted Access Window we develop a simple and fairly accurate mathematical method to set up the parameters of the mechanisms in order to improve performance for both types of stations, i.e. to reduce power consumption for low-power stations and to increase throughput for the other ones.