Understanding OFDMA Technology in Wi-Fi

OFDMA (orthogonal frequency-division multiple access) is a technology used in Wi-Fi to improve wireless network performance. It works by establishing independently modulating subcarriers within frequencies, allowing for simultaneous transmissions to and from multiple clients. This technology is a type of OFDM (orthogonal frequency-division multiplexing) and is designed for multiple users, allocating in both the time domain and the frequency domain. OFDMA offers several benefits, including increased network capacity, reduced response times, and better performance for video and AI applications.

In the past, Wi-Fi standards were primarily intended for web browsing and email in low-density situations. However, with the increasing number of users and their data-intensive activities, new technologies like OFDMA are necessary to meet the growing demand for high-speed and efficient wireless networks.

OFDMA divides the Wi-Fi channel into smaller frequency allocations called resource units (RUs). These RUs are assigned to specific clients, allowing an access point to communicate with multiple clients simultaneously. Wi-Fi divides channels into multiple subcarriers, and by spacing these carriers orthogonally, OFDMA enables the division of channels into smaller units without interference.

The number of RUs assigned to each client is determined by factors such as device constraints, quality-of-service requirements, and packet size. The flexibility in scheduling, along with the parallel nature of OFDMA, increases the productive airtime efficiency, resulting in better performance and improved network capacity.

OFDMA is not limited to Wi-Fi networks. It is also used in the air interface stage of 5G New Radio (5G NR) for mobile connectivity. In addition, OFDM, the older technology, is one of the primary enabling technologies of 3G and 4G cellular service.

With the adoption of OFDMA in Wi-Fi, there are numerous network benefits. Some of these include:

• Increased data capacity: OFDMA allows radio waves to carry more data in shorter timeframes, enabling greater network capacity.
• Reduced response times: OFDMA reduces response times and enhances performance for video, artificial intelligence (AI), and virtual- and augmented-reality applications.
• Optimal resource allocation: OFDMA prevents Internet of Things (IoT) devices from using disproportionate network resources, ensuring fair allocation of resources.
• Efficient power allocation: OFDMA allows per-channel or per-subchannel power and lower maximal transmission power for low-data-rate users, conserving battery life in devices.
• Improved service in high-density venues: OFDMA helps Wi-Fi provide better service in high-density venues such as airports, lecture halls, and sports arenas.

Wi-Fi with OFDMA opens up possibilities for a new era of wireless computing. Its higher capacity and more efficient networks enable businesses to run more applications wirelessly than before. The speed and capacity of Wi-Fi with OFDMA can support the development of new applications as software engineers invent new ways to take advantage of this technology.