Latest rumor says Apple's 4-inch iPhone will be called the 'iPhone 5e'
The enhancements in addition to re-introducing the 4-inch form factor back into the iPhone line are support for Apple Pay, NFC, and VoLTE. As for a release date, MyDrivers pegs it as March, which would compliment previous reports that Apple will hold a Spring event later this year.
On the specs side, the iPhone 5e will allegedly come in both 16 and 64 GB configurations and will include an 8MP camera and A9 processor; although an A8 processor and 1GB of RAM may be used in order to hit a 3288 Yuan ($500) price goal.