But one other change could affect thousands of longtime mobile users, as Sprint plans to fully shut down the former Nextel network by the end of June. That move was planned before the Softbank deal, but the fine print of that agreement brings a symbolic change. In the middle of the year, around the same time that Sprint shuts down the proprietary iDEN system that dates back to the 1990s, Sprint is set to drop the Nextel name as it completes the Softbank merger.
Those may be the last significant shifts in the U.S. mobile market for years, as Sprint gains much-needed financial strength and spectrum, and T-Mobile doubles down on reaching cost-conscious consumers with another major low-price operator under its wing. As the FCC auctions off more spectrum bands in the years to come, the market might be reshaped by new entrants, though much of that spectrum isn't ideal and may just go to supplement existing networks. For now, there simply isn't much more consolidation to do, some analysts said.
The national carriers will continue buying smaller, regional operators for their spectrum licenses, in order to fill out their geographic coverage or their data capacity, Ovum analyst Daryl Schoolar said. This trend is already ongoing and reflects the reality of the mobile industry, which now depends more on having fast, expensive new networks and the latest phones, analysts said. "A small business cannot compete and cannot build a successful wireless network today," Entner said.
Carrier mergers themselves are partly an artifact of the U.S. approach to mobile spectrum licenses, which mostly are allocated for individual markets rather than the country as a whole, Entner said.
In many countries including China, Japan, South Korea, Mexico, and parts of Europe, governments determine the number of national carriers through the number of national licenses they auction or otherwise award.
However, choices in the U.S. market may have to further shrink in the next year or two, some analysts said.
"I think T-Mobile is in the most precarious spot," analyst Jack Gold of J. Gold Associates said. Even with the spectrum it would gain from buying MetroPCS, the company will find it hard to compete with the top two carriers plus a stronger Sprint, he said.
Further consolidation to three carriers may even be inevitable, according to Chetan Sharma, at Chetan Sharma Consulting. He believes T-Mobile will be acquired in the next two years, possibly by a foreign operator or private investment group, but probably by Sprint. Neither of the two ultimately will be able to compete on their own, he said. In other countries where the mobile business is relatively open, such as the U.K., market forces eventually have led to greater consolidation, according to Sharma.
"Every time, in any market, you have multiple operators, they always whittle down to three," Sharma said.