Complex sentence: Following the acquisition by AT&T, Cricket will begin releasing devices capable of accessing AT&T's 3G, HSPA +, and 4G LTE network that covers 99% of the United States.
Split into simpler sentences: Following the acquisition by AT&T, Cricket will begin releasing devices capable of accessing AT&T's 3G, HSPA +, and 4G LTE network. Once on the AT&T network, Cricket customers will have coverage in 99% of the United States.