AT&T Inc. has reached speeds of up to 14 gigabits a second in lab trials of 5G wireless technology, and plans to test the high-speed network by beaming its DirecTV Now video service to homes in Austin, Texas before midyear. Through a collaboration with a dozen partners including Intel Corp., Ericsson AB and Qualcomm Inc., AT&T plans to use experimental airwaves to test fifth-generation or 5G residential and business services as a potentially cheaper method than fiber-optic cable for high-capacity connections, said John Donovan, AT&T’s chief strategy officer.