Longbow says that AT&T's (T) spending on CommScope's (COMM) solutions unexpectedly slowed in late Q2 and into Q3. The firm says its source estimates that AT&T's spending has dropped by three percentage points. As a result, Longbow estimates that Commscope's North American 2016 revenue is now flat to up low single digits versus its previous outlook of up low single digits. However, the firm keeps a Buy rating on the shares. It adds that Crown Castle (CCI), American Tower (AMT), SBA Communications (SBAC), and Ericsson (ERIC) have a negative read through from the news.