The Global Mobile Suppliers Association (GSA) has forecast that with the current annual growth rate of 140% the number of LTE subscriptions world wide will top one billion by the end of 2015.
The rapid growth in 4G LTE is in part due to the fact that it is the first generation and standard which has worldwide acceptance. For 1G there were a dozen different standards with USA, UK, Italy, Japan, the Nordic Countries, Germany, France etc all having their own standards and spectrum bands. 2G saw just four widely used standards GSM, D-AMPS, CDMA and PDC uniquely in Japan. 3G narrowed to three widely used standards WCDMA, CDMA/EV-DO and TD-SCDMA uniquely in China and finally with 4G LTE, with the standard widened to accommodate FDMA and TDMA variants and 44 (at last count) frequency bands, the single standard. 5G from 2020 should follow this lead.
The GSA reports that 30% of global operators have launched LTE (422 operators in 143 countries) with 2/3rds of these in 45 countries having commercial LTE-A mostly supporting carrier aggregation CA with category 6 devices giving up to 300 Mbps in the downlink (50 Mbps up) using 2X20MHz CA. There are, the GSA says, 3,253 (and counting) different LTE capable mobile devices from 305 suppliers in the world market.