OFDMA — Orthogonal Frequency Division Multiple Access — is the core innovation that separates WiFi 6 from everything that came before it. The marketing copy says WiFi 6 is better in crowded environments, and it is true. OFDMA is specifically why. The Problem With How Older WiFi Worked Every WiFi standard from 802.11a through WiFi 5 used OFDM — Orthogonal Frequency Division Multiplexing — as its physical layer transmission scheme. OFDM is excellent.