Briefly Explain the Radio Technologies in Use Today to Connect

Briefly explain the radio technologies in use today to connect mobile phones to a cell tower and the internet.
Code Division Multiple Access (CDMA) and Global System for Mobile Communication (GSM) are the two radio systems available for connecting mobile devices to cell towers and the Internet. CDMA uses a single frequency, and the subscriber information is contained within the handset and in a provider database. GSM uses multiple frequencies and a removable SIM card, and is the most widely accepted technology.