Little is known about the upcoming Sony Xperia models, and according to Tech Tree, it is unlikely that the company can release their flagship Xperia Z5 Plus by the end of the year.

And in case you're wondering, no, you didn't skip on the Z4, as the Z3 Plus is known as the Z4 in some markets.

However, while the Xperia Z5 Plus is still awaiting its release, the company is expected to see the lower-end models - the Z5 and Z5 Compact - at the IFA 2015 in Germany this September, where there is a good chance for it to formally launch.

For now, most of the things that we know about the latest Xperia models are all but rumors, however here are some of the ones that could possibly be true about the Sony Zperia Z5, Z5 Compact, and Z5 Plus, as reported by Yibada:

1) All three models are expected to be run by the Qualcomm Snapdragon 810 processor instead of the more powerful Snapdragon 820 processor.

2) The Z5 and Z5 Compact will sport a fingerprint scanner.

3) The Xperia Z5 will come with the latest version of the Android - straight out of the box with the Marshmallow, as reported by Gospel Herald.

4) Other Xperia Z5 features include a 3GB RAM, 20.7MP main camera, 8MP front-facing camera, and a 5.5-inch full HD display, and a 32GB internal storage.

5) Some of the Z5 devices may use Sony's 4K X-Reality technology, which is used for content upscaling in Sony's high-res television range. However, it is not clear which of the models will sport such tech, although Android Authority thinks this will be available for the Xperia Z5 Plus.

6) Previous leaks indicate that the Xperia Z5 Compact and Z5 will have USB type-C connectivity.

7) No price has been mentioned yet, although it should not be too far off the original price of the previous models.

While there isn't much to learn about the Xperia Z5 yet, Sony is due to release a smartphone this month - the Sony Xperia M5, which features a 5.50inch display screen and a 1080 x 1920 resolution.

The M5 is expected to run on Mediatek MT6795 processor with 3GB RAM and a higher 21.5 MP rear camera.

The Xperia C5 Ultra is also reported to be in the works, although Christian Today reported that there has been no information about it yet, so techies will have to wait until further notice regarding its arrival on the market.

Which of the latest Xperia models are you most excited to see? Are you waiting for the Z4 models, the nearing release of the M5, or are you curious about the C5 Ultra?