AT&T and Verizon set to deliver earnings as wireless competition builds

Even with minimal impact from the latest iPhone launch, the growing competitiveness of the wireless industry will be on full display when telecommunications companies start reporting quarterly results in the week ahead.

Wireless companies have become heavily promotional in recent quarters, a move intended to not only drive device upgrades, but also, crucially, to spur adoption of pricier unlimited plans. The telecommunications industry has incentive to move customers to more expensive plans as a way to help recoup heavy investments…