What are CDMA, Glide, and Leanse? These are the three types of mobile frequencies available for use in AT&T’s Advanced Network Services (ANS) and T-Mobile’s Visual Network Service (VNS). CDMA is a type of sub-space code designated by the International Telecommunication Organizations (ITO) as the main standards body for global cell phone communications. It was designed to serve as a global standard for mobile devices, replacing the older BSR (blue-to-white) technology used in the global market. The GSM code was chosen to be the globally accepted code for the purpose of enabling IMEI numbers to be used by cell phone users everywhere to connect to the network.