Actually several phones already offer that like the Samsung S3. ALl that was needed was two CDMA radios not unlike the way AT&T accomplishes this with two radios with GSM. One CDMA radio was used for voice and the other for data which could use either LTE or EVDO. There were a few CDMA phone that did this. The S4 skipped this since it was really a dead end with 1X advanced and VoLTE coming.
7/1/13 at 9:12am