HTC One is on display at a store. (Reuters)Reuters

The Taiwanese firm, HTC, has garnered a lot of praise for its flagship HTC One phone series for the past two years. Now the company is hard at work building its successor codenamed M9 with several upgrades in terms of internal hardware.

To help get a better perspective on the forthcoming HTC One (2015) aka M9, we have sifted through multiple reports to arrive at probable features that are likely to make the cut.

HTC One (2015) aka M9- Display and Build: We all know that HTC is the only Android OEM (Original Equipment Manufacturer) to have come close to perfecting the art of making aesthetically well designed smartphones. Well, the new HTC One (2015) is said to have the same design language that we have seen in the previous generation devices sans the size.

It is learnt that the M9 model will be a full-fledged phablet with a mammoth 5.5-inch Quad HD (aka 2K: 2560x1440p), which has become norm in the smartphone industry.

In terms of back-case specifications, HTC One M9 is expected to flaunt an Aluminum and Silicon-carbide alloy body to give a touch of premium finish. It's no wonder; HTC One series are often touted as Apple iPhones among Android devices in tech circles.

[Note: Galaxy Note 4, LG G3 and the 5.9-inch Google Nexus 6 have similar 2560x1440p display specifications]

HTC One (2015) aka M9- Mobile Operating System:

Since the new device is slated to debut in 2015, HTC One M9 will most likely ship with Android 5.0 Lollipop with latest HTC Sense UI.

HTC One (2015) aka M9- Processor, RAM, Storage capacity:

After Samsung Galaxy S5 made its debut in late February with a 2GB RAM, many HTC fans anticipated the company to release One M8 with higher capacity, but it never materialized.

[Note: RAM is essential for optimal performance of a device, higher the capacity, more efficiently the phone performs]

Now, if Chinese technology website, My Drivers is to be believed, HTC's 2015 flagship will reportedly house 3GB RAM and come packed with Snapdragon 805 series quad-core processor.

Though many appreciate the use of 3GB RAM, there are certain doubts over the CPU because the new Android 5.0 Lollipop is said to be compatible with 64-bit architecture based processors.

So, there is a slight chance of HTC using the recently unveiled Qualcomm Snapdragon 810 series Octa-core chipset to make it a worthy challenger to its competitors

Even the rival Samsung is also reportedly using the same Snapdragon 810 series silicon chip for its upcoming Galaxy S6 LTE model.

[Read more: Samsung 'Project Zero' aka Galaxy S6 Release Date, Specification Details: What we Know so Far]

HTC One (2015) aka M9- Camera specifications:

In 2013, the company boasted that the HTC One model was the industry's first smartphone to feature an innovative UltraPixel camera, but it did not live up to the expectations of the tech critics and fans alike. The smartphone's camera fell short against rivals like Nokia Lumia 1020, Galaxy S4 and Xperia Z1.

And again, HTC introduced the One M8 with the same Ultra-pixel technology based main camera, but with a secondary camera on the rear side to assist in capturing the depth of the object. This too failed to impress the tech pundits.

Now, rumour has it that HTC has reportedly dumped the flop ultra-pixel camera technology in the upcoming HTC One M9 model. It is likely to use a conventional 16.0-megapixel camera with OIS (Optical Image Stabilizations) and incorporate some value-added photography enhancing features. The company has already released in-house software programmers' developed HTC Eye Experience apps to the current flagship models.

The new HTC One M9 too is expected to come with the same features out-of-the-box, probably with more apps as well.

[Read More: Android 4.4.4 KitKat with Eye Experience OTA Update Released to HTC One M8]

HTC One (2015) aka M9- Battery:

5.0-inch HTC One M8 came with 2600 mAh battery, now its successor is said to get a major upgrade of 3500 mAh cell to power the energy guzzling 5.5inch QHD display.

HTC One (2015) aka M9- Value-added features:

Besides classic smartphone design, HTC smartphones are also well known for their HTC Boom Sound dual-stereo speakers. Now, rumor has it that the Taiwanese company will up the ante for One M9 to give enhanced music experience to its fans.

It is learnt that HTC is reportedly in talks with one of the pioneers of audio industry, Bose Corporation, to incorporate the finest sound equipment in the upcoming flagship model.

HTC One (2015) aka M9- Release details:

HTC One M8 made its debut in late March this year, so in all probability HTC is likely to announce its successor the same time next year.

Rumor has it that HTC One M9 might accompany a flagship 'Prime' model, which is said to be the successor of the 2013 HTC One Max.

Rumoured specifications of HTC One (2015) aka M9:

Model HTC One (2015) Codename : M9
Display 5.5-inch Quad HD (aka 2K: 2560x1440p)Pixel density: 530 plus ppi (pixels per inch)
OS Android 5.0 Lollipop with custom UI Sense v6.0
Processor 2.7GHz Snapdragon 805 series quad-core processor or 64-bit class based Snapdragon 810 series
Storage capacity Expected to come in 64GB/128GB
Camera Main: 16.0-megapixel camera with OIS (Optical Image Stabilizations) feature
Battery Around 3500 mAh
Add-ons Aluminum silicon-carbide based body, Bose audio speakers, microSD card slot,