RE:test5 Edgewater is in the midst of renewing it's OFDM patent. Seems it now has to be renewed every 3 years. I believe wifi6 primarily uses OFDMA. Maybe Kuiper will expound on that.
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The main difference between an OFDM and an OFDMA (Orthogonal Frequency Division Multiple Access) system is the fact that in OFDM the users are allocated on the time domain only, while in using an OFDMA system the user would be allocated by both time and frequency. ... For the uplink, SC-FDMA will be used.