ABI Research estimates that 676 million 4G LTE handsets will be shipped in 2015, increasing by 204 million units from 2014. Furthermore, the research company estimates that the total number of LTE connected devices shipped worldwide will exceed 1.89 billion units by end 2019, demonstrating the need for infrastructure and spectrum to support the stellar growth in the industry. LTE Advanced is now commercial on 20 networks in 14 countries. To cope with the demand for higher data rates, FDD/TDD LTE carrier aggregation trials are starting to take place. For example, Ericsson, SingTel, and Qualcomm demonstrated a downlink speed of 260 Mbps in their trial. The first ever TDD-FDD LTE trial took place in February 2014 between Korea Telecom and SK Telecom, with assistance from Nokia Networks. Release