If you're a T-Mobile subscriber with a 3G phone, you may have to make an equipment switch in the future. The good news is...it's not likely to be necessary anytime soon. If the proposed acquisition of T-Mobile by AT&T Inc., which will be taking the fourth-place U.S. wireless company off the hands of Deutsche Telekom if regulatory approval goes through, T-Mobile subscribers with 3G phones will need to replace those to keep their wireless broadband service working. But relax: it's not going to happen next week. All things considered, it will probably take about a year for the acquisition to happen, since it still needs to run the gamut of U.S. regulatory approval.

AT&T said that some time after the closing, it plans to rearrange how T-Mobile's cell towers work. The airwaves they use for third-generation services, or 3G, will be repurposed for 4G, which is faster, reported the Associated Press.

That would leave current T-Mobile phones without 3G. They would need to be replaced with phones that use AT&T's 3G frequencies. Ralph de la Vega, AT&T's head of wireless and consumer services, said this will happen as part of the normal phone upgrade process. “There's nothing for them to worry about ... it will be done over time, in a way that's good for customers and good for AT&T,” said de la Vega in an interview.

The whole process will take several years, said de la Vega. AT&T did not mention if customers would need to pay for their replacement handsets or not.

AT&T shares rose 27 cents to $28.21 in midday trading Monday.