With UEQM, stronger streams can use higher-order modulation, while weaker streams can fall back to more robust modulation
Unequal modulation (UEQM) in Wi-Fi 8 refers to the ability to assign different modulation orders to different spatial streams in a Multi-Input Multi-Output (MIMO) connection based on each stream’s individual signal quality.
In previous generations of Wi-Fi, including Wi-Fi 7, all spatial streams had to use the same modulation and coding scheme (MCS) even when some streams had stronger signal conditions than others, which could limit overall performance to the weakest stream. As LitePoint’s Product Manager Khushboo Kalyani told RCR Wireless News: “If you’re using MIMO, which many devices are these days, your throughput is limited by the weakest link.”
But with UEQM, each stream can adapt independently: Stronger streams can use higher-order modulation (faster rates), while weaker streams can fall back to more robust (lower-order) modulation. Overall, this results in more efficient and reliable traffic links.
“Based on your channel conditions, you can use higher modulation on a channel experiencing better conditions versus lower modulation if your other channel is experiencing poor conditions,” explained Kalyani. “You’re optimizing the available channels that you have… to increase your odds of successful transmission. It’s not just higher throughput, but odds of success.”
She is also careful, though, to point out that Wi-Fi 8 hasn’t introduced any new modulation schemes; instead, the upgrade is about how existing modulation is applied and coordinated — allowing different spatial streams to operate at different modulation levels based on real-time channel conditions.
This is particularly valuable as Wi-Fi 8 pushes toward ultra-high reliability (UHR) — a shift away from just maximizing peak speed toward delivering consistent performance across many devices and conditions. UEQM is just one of several physical-layer enhancements in Wi-Fi 8 aimed at increasing robustness and efficiency under real-world conditions. Other improvements include:
- Expanded MCS values to smooth transitions when signal quality changes.
- Coordination between multiple access points for better performance in dense environments.
- Enhanced long-range PPDUs and distributed resource units (DRU) for improved range and uplink performance.
As Wi-Fi 8 evolves to support AI-driven and latency-sensitive workloads, reliability is becoming a defining priority — because how quickly and consistently data moves through the network directly affects how fast AI systems can process it.
“Although with Wi-Fi 8, the goal [has] kind of fundamentally shifted towards reliability… because now with AI coming into the picture and… fueled by data, wireless technology helps to move that data. And it’s not just about how fast you can move it, but [with] how much lower latency can you move it,” said Kalyani.
