The next iPhone will only have minor improvements

More evidence is suggesting that the iPhone that will come out this fall will be a slight upgrade from the current iPhone 6S and 6S Plus.

Basically, it sounds like Apple is preparing another "S" model for release later this year, with a body that will be very similar to the iPhone hardware currently on sale.

According to Nikkei, the big changes to this year's iPhone will be:

1. A better camera
2. Water resistance
3. Larger battery
4. No headphone jack
5. A "high-end version" with photo "correction functions" - likely the dual-lens camera that's been rumored.

Nikkei cites supply chain sources and a production schedule provided to Apple suppliers:

Apple will likely take three years between full-model changes of its iPhone devices, a year longer than the current cycle. In a typical two-year term, fall 2016 was supposed to see a major upgrade. But the changes on the model to be launched this autumn will be minor, such as improved camera quality.

As has previously been reported, if this year's iPhone isn't a huge change, then the 2017 iPhone will be a big refresh. It's reportedly going to have a glass body, wireless charging, and perhaps an edge-to-edge screen.

Nikkei adds that the 2017 iPhone may have an improved vibration motor as well.

An Apple chassis supplier's CEO recently confirmed that he believes that Apple is preparing a glass iPhone in 2017.

If Apple is in fact moving to a three-year development cycle, it raises the question: Will this year's iPhone be named the "iPhone 7," or is Apple planning to totally change its naming convention?