SAN JOSE (WiMAX Day). Covad Wireless announced that it has successfully completed a trial of WiMAX in the area of the San Francisco Bay in America. According to a company spokesman, the trial used 5.4 GHz and 5.8 GHz frequency bands. The company is planning to use deploy WiMAX at selected base stations later this year for new subscribers, and for upgrading some existing base station equipment. Covad operates a large broadband fixed wireless network that serves some 4,000 small and medium-sized businesses in the San Francisco Bay Area, greater Los Angeles area, Chicago and Las Vegas.