สัญลักษณ์ Dtac หน้าศูนย์บริการ DtacDTAC customers at a service centre in Bangkok. The company says its entire customer base of 21 million could face mobile network problems after the 850MHz switch-off.++++++++++++++Published caption::DTAC decided to bid on the second-round auction for  a 900MHz licence. PORNPROM SATRABHAYA