NEW YORK — 5G E? 5G Plus? 5G Ultrawideband? Will the real 5G please stand up? AT&T has drawn ridicule by relabeling the network used by some of its phones as “5G E” to signal that the next-generation wireless network is here. Problem is, phones capable of connecting to 5G aren’t coming for another few months, and a national 5G network won’t be deployed until 2020 or 2021. But Verizon, which complained Tuesday about AT&T’s move, did something similar when it launched a residential wireless service with the 5G moniker using its own proprietary technology.