Modern telecommunications in Thailand began in 1875 with the deployment of the first telegraph service. Historically, the development of telecommunication networks in Thailand were in the hands of the public sector. Government organisations were established to provide telegraph, telephone, radio, and television services, and other government agencies, especially the military, still control a large estate of radio and television spectra. Private telecommunication operators initially acquired concession agreements with state enterprises. For mobile phone services, all the concessions have been amended by successive government to last 25 years have gradually ended in 2015. For other services, the concession terms and conditions vary, ranging from one to fifteen years. Nearly all of the concessions are build-operate-transfer (BTO) contracts. The private investor has to build all the required facilities and transfer them to the state before they can operate or offer services to public.