The Beacon

Uplink-OFDMA, a game changer for Wi-Fi CERTIFIED™ networks

Nitin Madan

The newest evolution of Wi-Fi®Wi-Fi CERTIFIED 6™—is designed with the Wi-Fi users of today and the trends of tomorrow in mind. Wi-Fi CERTIFIED 6 is based on the IEEE 802.11ax standard, with technical advancements that make it the fastest and the most versatile Wi-Fi yet. While each successive generation of Wi-Fi has been faster than the previous generation, improvements in Wi-Fi CERTIFIED 6 are not just about peak speeds.

We demand a lot from Wi-Fi at home: a typical family will have many more connected devices in the near future - such as phones, laptops, tablets, TVs, printers, security cameras, and more. We expect Wi-Fi to work hard in crowded environments, particularly at events such as sports games and music concerts, where fans generate multiple terabytes of data posting videos, status updates, and streaming live content from the venue. A lot of connected devices can mean some serious strain on Wi-Fi routers, leading to a bottleneck of traffic. What follows are slowdowns, buffering, and less efficient networks. Improvements in Wi-Fi CERTIFIED 6 such as Uplink-OFDMA (Orthogonal Frequency Division Multiple Access) and Downlink-OFDMA are focused on supporting a large number of devices operating close together, even when consuming large amounts of data.

OFDMA forms the backbone of Wi-Fi CERTIFIED 6 and makes the sixth generation of Wi-Fi more efficient, more reliable, and more versatile than previous generations. This innovation allows Wi-Fi CERTIFIED 6 to support many devices at the same time, and to diminish the interference that causes congestion in Wi-Fi networks today. A major factor limiting current Wi-Fi is collisions: when multiple devices transmit at the same time and interfere with each other. With OFDMA, each slice of spectrum is separated into many smaller sub-channels, each with a slightly different frequency. Rather than waiting in line for their turn to transmit across the whole frequency channel, multiple devices will be able to share the channel simultaneously to increase overall network capacity and throughput. OFDMA adds flexibility to how spectrum is used, only allocating parts of the spectrum to each wireless device proportional to its needs. This is the Wi-Fi upgrade—with vastly increased capacity —that will effortlessly power the Internet of Things while simultaneously downloading data, streaming 4K video, and supporting Voice over Wi-Fi.

Additionally, Uplink-OFDMA may be one of the most important features of Wi-Fi CERTIFIED 6. Uplink-OFDMA reduces collisions and overhead, improving the performance of the network. This feature keeps the traffic traveling in both directions from colliding, and results in robust Wi-Fi networks capable of scheduling wireless traffic efficiently.

Uplink-OFDMA also increases the range of Wi-Fi networks. This is because it solves a problem that exists today - Wi-Fi connections are asymmetrical. Access points (APs) have more range than mobile devices. APs are usually plugged in to a power source, and hence, battery life is less of a concern. This allows them to transmit at a higher power than mobile devices. Meanwhile, mobile phones need to optimize battery life and transmit less power than their infrastructure counterparts. This limits the range of a Wi-Fi user because the phone cannot reach the AP, whereas the AP can reach the phone. With Wi-Fi CERTIFIED 6, the phone can concentrate its energy in a narrower channel – as narrow as 2 MHz – and reach the AP by boosting the peak power transmitted while remaining compliant with spectrum regulations. This feature solves the link budget asymmetry (as much as 10 dB) in legacy Wi-Fi which can double the communication range, reduces dead spots, and improves Wi-Fi performance for users, enterprises, mobile carriers, and internet service providers alike.

I believe that Uplink-OFDMA will be a game changer for the Wi-Fi industry and is one of the most important features of Wi-Fi CERTIFIED 6 products.

The statements and opinions by each Wi-Fi Alliance member and those providing comments are theirs alone, and do not reflect the opinions or views of Wi-Fi Alliance or any other member. Wi-Fi Alliance is not responsible for the accuracy of any of the information provided by any member in posting to or commenting on this blog. Concerns should be directed to

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Nitin Madan

Nitin Madan has 20 years of global experience in the wireless industry in sectors such as semiconductors, OEMs and Telecommunications. At the marketing team at Broadcom, which Nitin joined in 2014, he is focused on bringing new Wi-Fi technologies to market. Nitin has bachelor's and masters degree in Electrical Engineering, and in 2010, he received an MBA from the University of St. Gallen (HSG).