T-Mobile would get more spectrum than Verizon in the deal, and would pay an undisclosed sum in return. But the exchange will only happen if regulators approve Verizon's plan to purchase massive amounts of unlicensed spectrum from cable companies, which are abandoning their wireless ambitions and from Leap, a wireless holding company. Verizon's willingness to help out spectrum-starved T-Mobile could appease regulators.

Some of the answers for consumers are straightforward, and others, not so much.

Verizon and T-Mobile both say their customers will get better wireless coverage out of the deal. For Verizon, the swap would provide deeper and more contiguous coverage across many eastern U.S. markets, and would provide more Advanced Wireless Services spectrum--used for voice and data by certain smartphones--in 17 western U.S. markets.

T-Mobile says the extra spectrum will provide a boost in 15 of the top 25 U.S. markets, particularly Detroit, Philadelphia, Seattle, and Washington, D.C., . T-Mobile needs the extra spectrum as it tries to build a that can compete with AT&T, Sprint, and Verizon.