$AMT Goldman Sachs Upgrades American Tower To Buy, Raises Target To $270 Notes Co. Is Firm's 'favorite way to position for 5G'; Notes 'Domestic towers to benefit from: ‘1) carriers ramping 5G coverage in 2020, 2) the potential 2020 launch of a 5G iPhone, 3) higher data usage, driving cell site densification, 4) deployment of new spectrum bands and 5) deployment of massive MIMO’