American Tower Corporation’s (AMT) extensive and geographically diversified communication real estate portfolio positions it well to ride the growth curve amid rising capital spending by wireless carriers on the incremental demand from global 4G and 5G deployment efforts.Its expansionary efforts and disciplined capital-allocation strategy augur well for long-term growth. However, customer concentration poses a key concern for the company.What’s Aiding AMT Stock?With the advancement in mobile technology, suc ...