According to The Wall Street Journal, the next iPhone is currently in production stage and will be on store shelves this summer.
The publication writes that the iPhone 5S will feature a design that will be very similar to its predecessor and will especially feature a higher performance CPU.
This is something that Apple did earlier with the introduction of the iPhone 4S, which looked exactly like the iPhone 4.
In addition, the report states that the low-cost model will be announced during the second half of the year and that it will feature a 4-inch display.
This budget iPhone will likely be made of a material different from that used in the high-end model and Apple is said to have tested different colors for the casing.
Finally, the WSJ also reports that the next iOS release could take place around the middle of the year, which would be in line with Apple tradition.