As part of its recently announced merger with T-Mobile USA, MetroPCS will be moving customers off its current CDMA network by 2015, the company says. In a call, the companies said that T-Mobile's GSM network would provide 3G service for MetroPCS subscribers, while the CDMA spectrum would be repurposed to expand 4G LTE. "At the date the deal closes," investors were told, "we will have an array of GSM, HSPA+, and LTE devices available for MetroPCS customers to purchase." Previously, MetroPCS had considered signing roaming partnerships with GSM carriers, using Voice over LTE to make the switch.

Citing a 60 to 65 percent annual upgrade rate, they said that the transition should not be difficult, and that "heavy users" on LTE would likely migrate immediately. By 2015, the new T-Mobile will begin shutting down MetroPCS cell sites and using that spectrum for an LTE network it hopes will rival that of AT&T or Verizon. For people who are slow to make the switch, it could also offer incentives for the last 8 to 12 months.

"Nextel customers saw a loss of functionality, where MetroPCS customers will see immediate benefits."

T-Mobile was quick to draw distinctions between its merger and that of Sprint and Nextel in 2005. "History will show that Nextel customers saw a loss of functionality," an executive said, "where MetroPCS customers will see immediate benefits." It also plans to maintain the focus on low-cost, contract-free service, which it said was growing at a much faster pace than traditional contract subscriptions. While there's still a while before the merger is even completed, the two companies have answered many of the questions about how customers will be affected. Still conspicuously absent, however, is any mention of the iPhone, which isn't currently available on either carrier.