https://www.theverge.com/2018/12/5/18126980/att-samsung-5g-phone-mmwave-sub-6ghz-smartphone-network

AT&T will launch a second Samsung phone on its 5G network in 2019 in addition to the one it announced less than 24 hours ago, the company has confirmed. However, unlike the Samsung phone due in the first half of the year, this second 5G handset, due in the second half of the year, will be able to access sub-6GHz spectrum in addition to mmWave, according to an AT&T representative. It will be the third 5G device from AT&T overall if you count Netgear’s 5G mobile hotspot.

News of a second Samsung phone that also supports a wider swath of 5G spectrum could Osborne the first. After all, who wants to spend upwards of $1,000 on a flagship 5G phone that could be handicapped by 5G coverage? Both mmWave and sub-6GHz have distinct advantages that will make them necessary for 5G. Millimeter wave (mmWave) spectrum provides speeds up to around 1Gbps and ultra-low latency in theoretical everyday usage, but struggles to penetrate into buildings, while sub-6GHz provides broader coverage but at slower speeds using existing spectrum. Verizon and AT&T have said they’re prioritizing the speedier mmWave spectrum for 5G, but sub-6GHz 5G spectrum will likely be needed to achieve the same coverage as 4G.