How is this different from WiMAX Compliant?
Any company could build WiMAX compliant radios from the technical specification standpoint. However, that does not mean those radios would work with other vendors gear. It is one thing to build a radio that meets a technical specification and quite another to ensure that vendor products (built with varying engineering methodologies and manufacturing processes) actually work together well in the real world. WiMAX CERTIFIED™ is the only stamp of approval for such gear.