One of the conditions in order to benefit from 4.5G technology is the replacement of third-generation SIM cards to fourth-generation ones. While nearly 52 million subscribers have changed their SIM cards already, it will continue free of charge until the end of the year.According to Anadolu Agency (AA), Turkey first met 1G technology in 1991 with car phones, followed by the Internet in 1993. Turkey also started using 2G technology enabling users to transfer data and send SMS in 1994. Starting to use 3G network in 2009 when data gained larger importance along with sound transfer, Turkey welcomed the 4.5G era in telecommunication on April 1, 2016.In order to benefit from the new technology, SIM cards and phones have to be compatible with 4.5G technology. While operators are willing to change SIM cards free of charge until the end of the year, they can demand payment for SIM card change as of Jan. 1, 2017.Out of 75.6 million cellphone accounts in Turkey, nearly 17.2 million users are using 4.5G-compatible mobile devices and nearly 52 million subscribers have already replaced their old SIM cards with 4.5G compatible ones.