The plan is for Sprint to launch its next-generation push-to-talk services in the fourth quarter this year when the company completes a large expansion of its CDMA-based PTT network. Sprint plans to cover 2.7 million square miles with its CDMA-based PTT network by year-end, or roughly triple the 908,000 square miles that it covers with the iDEN PTT network. Sprint will open up much larger chunks of spectrum for its PTT customers to improve coverage, including spectrum on the 800MHz, 1.9GHz and 2.5GHz bands. The carrier also wants to add a wider variety of PTT-capable handsets to its catalogs, including a touchscreen PTT phone.

Sprint's iDEN network has been a major headache for the carrier, as it has cost Sprint literally millions of customers ever since in 2005. Last quarter, for instance, Sprint recorded losses of 395,000 postpaid iDEN subscribers and 768,000 prepaid iDEN subscribers. These losses both offset the significant gains made by Sprint's CDMA network last quarter in both the postpaid market (453,000 net additions) and the prepaid market (1.4 million net additions).

The good news from this perspective is that Sprint plans to phase out its iDEN network altogether in 2013, so the network's days of being an albatross for the carrier are limited. Even if Sprint weren't planning to phase out its iDEN network, it may have simply run out of iDEN customers by 2013 no matter what, as the carrier has lost nearly 4 million iDEN subscribers over the past two years alone.

Sprint has been slowly but surely rebounding from a disastrous four-year period where it lost 5 million total subscribers between 2007 and 2010. At its lowest point in the third quarter of 2008, Sprint lost a whopping 1.3 million wireless subscribers, and for all of 2008 Sprint lost more than 4 million wireless subscribers.