Mobile WiMAX is currently available only for TDD, while Release 1.5 will introduce FDD. Most cellular technologies today are FDD based, while LTE is defined for both. (Did I mention LTE and Mobile WiMAX are not that different?)
Rule Number One of Wireless Communications: No Spectrum -> No Business
(Well, except non-licensed band, but let’s keep it for another Post).
This is an important step taken by the Japanese regulator to push IMT-2000 and Advanced forward, and allowing Japanese Mobile operators the room to grow!