Mobile World Congress gets under way in Barcelona tomorrow: the annual showcase for new apps, phones, tablets and everything mobile for the year ahead. We round up the flagship smartphones rumoured for 2015, and the new features and specs that we could see unveiled.

MWC 2015 is just around the corner, with the first press events taking place tomorrow, Sunday 1st March.

LG kicks things off at midday, where it will once again show-off its G Flex 2 curved smartphone. This will be followed by an HTC press conference, where the company is expected to show-off the HTC One (M9), and Samsung Unpacked, where we expect to see the Galaxy S6 and S6 Edge.

So which devices will be grabbing the headlines? With tablets falling out of favour, we take a look at the flagship smartphones we expect to see later this year and which could represent the best phones unveiled of MWC 2015...

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Samsung Galaxy S6

Samsung has sent out press invitations for its Galaxy Unpacked event, which takes place on 1st March at 18:30 CET.

So, we know we'll see a new Samsung phone at MWC. The invite simply says, "What's next", along with an image of a device with a curve. The new Galaxy S6 is the hot favourite.

The Samsung Galaxy S6 screen is likely to receive a boost in resolution. With the likes of the Samsung Galaxy Note 4 and LG's G3 already featuring 2560 x 1440 screens, we'd be surprised if the S6 didn't receive the same. 

The Galaxy S6 specs are rumoured to be a 5.5in screen, 3GB of RAM and either a Qualcomm Snapdragon 810 processor or Samsung's own Exynos processor. Storage is expected to come in 32GB, 64GB and 128GB variants, and 20-megapixel camera has also been predicted.

The shiny nature of the image on the invite also points toward a metal construction. Could Samsung finally be ditching the much-bemoaned plastic from its Galaxy range, in favour of a metal unibody design? With Apple, HTC and Sony all using metal in their phones for a more premium feel, it seems obvious for Samsung to follow suit - certainly the recently released promo video for the announcement seems to all but confirm it. Take a look above to see for yourself.

As for leaked pictures, French website Nowhereelse.fr (PhoneArena translation) has obtained images purporting to be the Galaxy S6. The images support the rumoured metal design, with curved edges and corners that look strikingly similar to the iPhone 6.

MORE: Samsung Galaxy S5 review

Galaxy S6 Edge?

The article also quotes an executive parts-supplier as saying "The Galaxy S6 will make its debut in two versions - flat and rounded screens. It will have a metal build, which will make it look even more like Apple's latest models." Could this point to a separate model, the Galaxy S Edge?

Androidworld.it has found a placeholder page on the Vodafone Netherlands website, which also mentions a Galaxy S Edge.

The Galaxy S Edge could take a similar form to that of the Galaxy Note Edge (Stuff.tv review), which features a screen that curves off at the edge. The extra screen real estate is used for application shortcuts and notifications, leaving the rest of the screen available for general use. 

   

More after the break

HTC One (M9)

HTC has also sent out press invites for its event at MWC 2015, which will also take place on 1st March at 16:00 CET; two-and-a-half hours before Samsung's unveiling. 

The event is likely to be based around HTC's new flagship, the HTC One (M9). The Hima name came from usually reliable Twitter leaker, @upleaks, who seemingly confirmed the HTC Hima will be marketed as the HTC One (M9).

MORE: HTC One (M9): release date, news and rumours

The new flagship is expected to look like its M8 predecessor, sporting a metal unibody design and curved back. The only real change will be the relocation of the power button from the top, to the side.

Another big change is likely to come in the camera department. HTC could be ditching its use of 'UltraPixel' in favour of megapixels. The One (M9) is expected to feature a new 20.7MP-sensor and either a 4MP-UltraPixel or 13MP-sensor on the front. 

There are conflicting opinions when it comes to the rumoured specs. Phandroid expects the One (M9) to include a Qualcomm Snapdragon 810 processor, 3GB of RAM, 5in full HD 1080p and 2840mAh battery.

The International Business Times, however, reports it will come with a Qualcomm Snapdragon 805 processor, 5.5in 2K screen, 64-bit computing and 64GB and 128GB storage options.

All will be revealed on Sunday at the HTC press conference at MWC.

Sony Xperia Z4

Sony hasn't sent out any invites to MWC yet, but that hasn't stopped speculation about what the company could unveil, given the fact we've seen not one, not two, but three new flagship Sony phones in the past 18 months.

The obvious choice is an Xperia Z4. One of the first things worth mentioning from a specs point of view is that Sony is reportedly poised to launch two versions of the Xperia Z4: one sporting a Quad HD (1440p) display and another with a Full HD (1080p) display.

Qualcomm has confirmed the Xperia Z4 will come packing the Snapdragon 810 chipset, which will bring a number of improvements, including 4G LTE speeds up to 450mbps and 4K support.

Sony is also likely to follow the similar Omni-balance design language of previous Xperia phones. We're fans of this look, particularly on the Xperia Z3, which brought rounder edges for a more comfortable grip.

A new 20.7MP-camera sensor is also expected to be introduced, which will offer 192-point auto-focus and real-time HDR.

MORE: Sony Xperia Z3 review

Xperia Z4 Music?

According to iGeek, there could also be a dedicated version of the new flagship smartphone – one aimed at music lovers. The rumoured Xperia Z4 Music pretty much combines the smartphone and the latest Sony Walkman into one high-res hybrid.

It'll support DSD, WAV, AIFF, ALAC and FLAC among other file types, as well as packing in S-Force Pro surround sound speakers. There could also be an extra-special headphone amplifier inside the Z4 to take care of all this audio expertise.

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LG G4

Perhaps the least likely phone to break cover at MWC, the LG G4 has some serious boots to fill: both the G2 and G3 were brilliant smartphones but, as ever, fresh competition means LG needs to keep innovating to keep the early-adopters happy. 

On the design front, it's highly likely any new LG flagship phone would feature the power and volume buttons on the back once again. LG believes this to be the natural place for fingers to rest when the phone is held in the hand; we think this works.

The G3 used a plastic casing but gave the impression of a brushed-metal effect. LG may want to follow in the footsteps of the HTC One (M8) and iPhone 6 and opt for an all-metal build. Alternatively, it could employ the same 'self-healing' technology that we've seen on the G Flex 2.

Much like the other 2015 flagship phones on this list, the G4 will likely come packing the Qualcomm Snapdragon 810 processor with 3GB of RAM.

The G3 was one of the first phones to arrive on the market with an eye-piercing 2K screen. If a recent screenshot, picked up by MyLGis to be believed, the G4 will up the resolution to 2880 x 1620 (expect to see "3K" on the marketing, then...).

Other rumours suggest the G4 will feature a smaller screen than before, at 5.3in, which would give 624 pixels per inch - double that of the iPhone 6's Retina display. 

LG is expected to stick with its laser auto-focus camera for the G4, although there's a possibility it will be bumped-up from 13MP to 16MP. The camera currently on the G3 is a real strength, so an update could make the G4 a seriously impressive camera-phone.

We'll be reporting live from MWC 2015 - and getting hands-on with the best smartphones and tablets unveiled at the show. 

 

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