Thai mobile operator TOT has approved a THB1.7 billion (US$50 million) plan to upgrade 500 1900MHz base stations owned by subsidiary Thai Mobile to offer 3G services in Bangkok by the end of this year, reports Telegeography, citing the Bangkok Post. A spokesman confirmed that TOT would initially offer retail 3G services, but it was also preparing to offer wholesale network capacity, and that one privately owned operator had already made an approach to resell services. The upgrade from GSM to WCDMA/HSPA is being handled by Ericsson and Nokia Siemens Networks.