Make no mistake that Sprint's iDEN network is not long for this world. In an interview with Fierce Wireless today, Sprint CEO Dan Hesse said eventually the carrier will replace its iDEN 800MHz spectrum with enhanced CDMAcoverage.

Though Hesse didn't give a specific time line for the transition, he characterized it part of the carrier's natural network evolution. "Over time, we'll have fewer and fewer customers on the iDEN network," he told the publication. "That allows us to use some of that capacity on the network that is freed up and use it for CDMA. It's a gradual process."

Over the past year, Sprint has introduced fewer iDEN handsets while highlighting CDMA Android devices and smartphones compatible with its growing WiMax 4G network. In fact since January, we've seen just thee iDEN handsets: the Motorola i1, the Motorola i890, and the Motorola Brute i680.

It's unclear what will happen to Nextel's popular and pioneering Direct Connect push-to-talk services when iDEN is phased out. Ever since Sprint acquired Nextel in 2005 for $35 billion the carrier has struggled to integrate the two brands and their compatible networks.