Sony Xperia Z3 Series devices
Sony Unveils New Z3 Series Xperia Smartphones, Tablet, Smart Wearables at IFA 2014Sony Mobile

Many Sony fans could have run out of patience with the much-awaited flagship device, the Sony Xperia Z4 not being released despite speculations around it. There were rumours that it would be announced at the CES 2015 and then at the World Congress 2015 (MWC 2015) but that never happened. Now, report has emerged that it would be pushed to the second of this year.

A report by PCAdvisor has claimed that the Sony Xperia Z4 would be unveiled at IFA 2015 to be held between 4 and 9 September. However, Sony is yet to confirm the release date of its next-generation device. 

"Z4 is the next-generation of product that we'll be announcing. No, we haven't [moved to a more traditional 12 month product cycle]. As a general rule you will see some adjustment to the way we phase our products, but we're certainly not going to offer any specific details as to when we are going to bring our next products, beyond these, at this stage," Tim Harrison, Sony's Vice President of Global Communications and PR, told TrustedReviews.

Meanwhile, the Sony Xperia Z4 is expected to have at five least feature upgrades over its predecessor, the Xperia Z3:

1) Display: The Sony Xperia Z4 is expected to sport a 5.2-inch, 5.4-inch or 5.5-inch screen 1440 x 2560px Triluminos display, while its predecessor has a 5.2-inch IPS LCD capacitive touchscreen with 1080 x 1920 pixels (424 ppi pixel density).

2) Processor: The Xperia Z3 is powered by Qualcomm Snapdragon 801, while its successor is expected to come with Qualcomm Snapdragon 810 processor.

3) Memory: The Sony Xperia Z4 is expected to come packed with 32GB internal memory and 4GB RAM, while its predecessor has 16/32 GB internal memory upgradable up to 128 GB and 3 GB RAM.

4) Camera: Sony's flagship device is expected to house a 20.7MP main camera and 4.8MP front snapper, while the Xperia Z3 has a 20.7 MP rear camera and 2.2 MP front snapper.

5) Battery: The Xperia Z3 ahs son-removable Li-Ion 3100 mAh battery while its successor is expected to come with 3420 mAh battery.

The next-generation device is also expected to have features like Qi Wireless Charging, Android 5.0 Lollipop, IP68 water and dust proof certification, and LTE Cat 9 connectivity.