Samsung has upped the excitement in the approach to Mobile World Congress 2014 in late-February, with an invitation to Unpacked 5: hotly tipped for the unveiling of the latest Samsung Galaxy handset. With the Samsung Galaxy S4 selling well, but not attracting the same degree of excitement as some rival devices - with the HTC One walking away with most of the 2013 awards - the Galaxy S5 is a key device for Samsung in 2014.

From possible release dates to improvements in build, camera and display, the claims are in full swing for the S4 successor and to make it easy for you, we have rounded them all up here.

Samsung Galaxy S5 release date

Samsung has sent out invitations for Samsung Unpacked 5 on Monday 24 February in Barcelona. The use of the "5" on the invitation is a strong suggestion that we'll be seeing the Samsung Galaxy S5 launch at the event, but the eagle-eyed amongst you will also have spotted the "episode 1" suggesting there will be other Unpacked events coming in 2014.

Online tipster @eldarmurtazin previously claimed that there would be a Samsung Unpacked 2014 event on 23 February, just one day out, but all eyes will now be focused on Samsung's confirmed event. According to the New York Times, the event will be more low-key than previous Samsung flagship launch events.

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Early reports from Korean site Joseilbo suggested the Samsung Galaxy S5 would be launching pretty sharpish in the new year. The site claimed internal Samsung meetings said the company would unveil the device in mid-January with it going on sale by February. This cycle wouldn't follow Samsung's usual Galaxy release pattern, which is normally in March/April, but with reports suggesting the S4 missed the company's internal sales projection despite it selling more than 40 million handsets worldwide, it wouldn't be an unreasonable timeline if Samsung wanted to shake things up a little early.

READ: Samsung Galaxy S4 review

Korean site ET News suggested manufacturing for the Galaxy S5 began in Vietnam in January, with the handset going on sale before the end of the quarter. But Lee Young Hee, executive vice president of the company's mobile business, at CES said: "We've been announcing our first flagship model in the first half of each year, around March and April, and we are still targeting for release around that time."

More recently, Samsung announced a refresh of its LED component solutions for mobile devices, although the company said they wouldn't go into full production until March. This suggests the Galaxy S5 is unlikely to hit stores before April if the new components are to make it onto the new flagship.

Samsung Galaxy S5 display

At its Analyst Day in Seoul, Samsung presented a road map of where it plans to take its screen resolutions over the next couple of years and it suggests we can expect a mighty bump for the Galaxy S5.

Although 4K displays were touted for 2015, Samsung proposed it would be taking a step up to a 2560 x 1440 pixel resolution display in the "gap" year, suggesting it's possible we could see it arrive on the S5. The company also said it was looking further into phones that can bend, flex, and even fold.

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There were rumours of a wraparound display also reported, but this could be for another device rather than the Galaxy S5, or perhaps the premium version if the two options-rumour is accurate. Until further evidence emerges, it seems we are looking at a 5-inch Super AMOLED display with a pixel density of 560ppi for the Galaxy S5, which would be super-sharp and class leading. If SamMobile is to be believed, it could be a 5.25-inch Super AMOLED display with a 2560 x 1440 pixel resolution.

However, there has also been a rumour to suggest Samsung will be ditching its Super AMOLED in favour of a Sharp Low Temperature PolySilicon (LTPS) LED display. The LTPS LCD display is said to be 100 times faster than amorphous silicon screens so it should have an excellent response rate if Sammy opt for it.

More recently, Ming-Chi Kuo, a KGI Securities analyst, reported that there would be two models of the Samsung Galaxy S5, both of which would have different display resolutions. He claimed both would come with a 5.2-inch display, but the "Prime" model would feature a 1440 x 2560 resolution (565ppi) and the "Standard" model would come with a 1080 x 1920 resolution (423ppi).

A leak on benchmarking site AnTuTu suggests one model will come with a 1440 x 2560 display, while the other model will feature a 1080 x 1920 display. Adding weight to the 2560 x 1440 pixels rumour, what claims to be leaked packaging for the SGS5 lists a QHD display - quad HD. The 2K display is something again mentioned in a Typhone listing for the SGS5, so there's certainly a volume of rumours supporting a step-up in resolution.

Samsung Galaxy S5 build

It looks like we can expect an improvement in the build of the next Galaxy device. According to Korean site ET News, the Galaxy S5 will be the first Galaxy device to replace a polycarbonate casing in favour of aluminium and magnesium alloy.

The site claims industry sources say that adopting a metal rear casing will help Samsung to compete directly with its rivals such as HTC and Apple whose flagships both feature premium quality bodies. It is also suggested that the design will be reinvigorated in terms of materials and aesthetics but no details were given, so for now this is just speculation.

But that isn't all in terms of build. According to Electronic Times, the Galaxy S5 is rumoured to be waterproof and dustproof from the box, taking some of the technology used in the S4 Active and following in the footsteps of Sony's Xperia Z and Xperia Z1.

The Samsung Galaxy S4 Active swapped a couple of the S4 specifications for a more rugged body and a camera that worked underwater but it isn't likely Samsung will want to increase the size or weight of the S5. This could just be a case of fans drawing up a wishlist of specs, we're not entirely convinced that the S5 will make this move.

READ: Samsung Galaxy S4 Active review

One of the most interesting rumours to emerge is the idea that Samsung will release two versions of the Galaxy S5, just like Apple did with its latest iPhone, bringing the iPhone 5S and more affordable iPhone 5C.

The rumour comes from ET News and claims both versions will come with the same specifications, but the premium device will sport a metal casing and flexible display, while the other option will be a plastic casing and normal screen.

SamMobile also suggests there will be two versions of the Galaxy S5, one plastic and one metal with the plastic option said to cost around €650 and the metal around €800.

However, analyst Ming-Chi Kuo says also says there will be two versions, but he claims both will be plastic and one will be called Prime and the other Standard.

More recently, two variations of the potential Samsung Galaxy S5 have appeared on the AnTuTu benchmarking site in the form of the SM-G900R4 and the SM-G900H.

There is a chance the S5 will scan and recognise your eyes for another layer of security. Lee Young Hee, executive vice president of the company's mobile business, said: "Many people are fanatical about iris recognition technology. We are studying the possibility."

The iris sensor has also been suggested by a tipster who claims the Galaxy S5 will have a "state of the art iris sensor and wide range of health accessories".

More recently however, the iris technology is said to have been ditched due to problems that could arise when the user is in a dark area but the Korea Herald has reported that a fingerprint sensor under the display panel could be coming to the handset instead. ETNews has also supported the idea of a fingerprint sensor, claiming the part is being built in-house at the company and will be a swipe recognition system rather than the touch-and-hold affair we saw on the Apple iPhone 5S.

One thing is certain though: Samsung has done a good job of keeping the SGS5 away from prying eyes. Unlike the new HTC One, there have been very few reported photos of the new handset.

Samsung Galaxy S5 camera

Samsung is working on a new 16-megapixel sensor with optical image stabilisation according to a report from Korea in August. The sensor wasn't due to be ready in time for the Note 3, but it is said to have been designed specifically for its flagship slimline Android phones so the S5 has a good chance of being in the running.

The sensor is described by Samsung as "the world's highest-performance camera module" and its OIS allows for correcting angular errors of up to 1.5-degrees off target, reducing blur and increasing sharpness.

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If it makes it into the Galaxy S5 it will mean shots and full HD video recordings will be eight times brighter than other competing sensors, according to Samsung. We'd also expect support for 4K video capture, as found in the Note 3.

In addition, the autofocus technology is said to have been improved, using less power and reducing the drain on the battery. The use of a 16-megapixel sensor appeared on a recent Typhone webpage too.

However, a tipster has also suggested to Phone Arena that the new flagship would be coming with a 20-megapixel sensor, like that of the Sony Xperia Z1. The tipster claimed the camera will feature new optical image stabilisation and will be able to record 4K video, while shooting images at the same time.

This rumour has been reinforced with the appearance of an image that claims to be from the SGS5. Although the photo doesn't show anything of detail, the data reveals that it is a 5312 x 2988 image in 16:9 aspect, which would equate to a 4:3 sensor of around 21 megapixels. It's listed as 20-megapixels on a recent SGS5 packaging shot too.

More recently however, there has been a benchmark leak from AnTuTu that reveals a 16-megapixel camera and 2-megapixel front camera, which would support the previous report from Korea, although the device name has been blacked out on the benchmark shots so it is worth taking this with a pinch of salt for now.

With a split between those saying it's 16MP and those saying its 20MP, it's difficult to be certain where the SGS5 is heading.

READ: Samsung Galaxy S4 Zoom review

One of the benefits of the new reflector-integrated flash LEDs is a wider field of view meaning the Galaxy S5 could come with a drastically improved flash over previous generations if the new LED components are introduced.

Samsung Galaxy S5 processor, battery and storage

Apple recently launched its iPhone 5S with a 64-bit processor under the hood and it looks as though we might see Samsung do the same.

According to Digitimes, Samsung Display and Japan Display will begin making its WQHD displays soon and 64-bit CPUs. Although the track record for Digitimes isn't flawless, the display rumour has appeared from another source previously so it could well have some legs in this case. The same report from Digitimes also suggested Samsung would be packing in a 16-megapixel camera, which was also claimed by another source.

The 64-bit processor does carry some further weight though, as Stephen Woo, Samsung's president of System LSI, said earlier in November the company would be following in Apple's footsteps with a 64-bit chip so we would imagine this is fairly likely for the S5.

More recently, SamMobile has suggested the Galaxy S5 will be sporting the Qualcomm Snapdragon 805 processor or an Exynos 6 depending on the market, but analyst Ming-Chi Kuo believes one model will come with a 32-bit octa-core Samsung Exynous 5430 processor, while the other will have a 32-bit quad-core Snapdragon 800 processor.

The Galaxy S5 was also rumoured to be coming to market with 3GB of RAM to match the Note 3 and a 4000mAh battery but recent rumours have suggested we could see 4GB RAM on the handset after the company recently announced it has developed the first LPDDR4 RAM.

If the double rate 4 RAM is introduced to the handset, you can expect faster applications, a longer battery life, more advanced features and possibly even a higher resolution display.

Samsung has said it will be introducing 64-bit processors in 2014, and these can support more RAM, so this jump to more-efficient 4GB LPDDR4 would make sense.

There have also been reports of a 2900mAh battery, although we are taking this rumour lightly for now as a 4000mAh battery would seem like a better option if the device comes with a 2K display.

The most recent rumours come from a leak on AnTuTu where two models were presented, one featuring a 2.5GHz Qualcomm Snapdragon 800 processor, 3GB of RAM and 32GB of internal storage, while the other had a 1.5GHz octal-core Exynos 5422 processor with Mali-T628 graphics, 2GB of RAM and 16GB of storage.

Samsung Galaxy S5 software

It is probably a safe bet that the Samsung Galaxy S5 will come with Android 4.4 KitKat, but a leak from @evleaks has suggested Samsung will also be refreshing its user interface on the Galaxy S5.

The company has not confirmed the leak, but if it is accurate, we could see a move away from the slightly cartoony look of the current UI, along with narrower fonts.

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The screenshots from the leak don't give much away but they do suggest the central screen will have live information on it such as a friend's location, in a design similar to BlinkFeed, and a more conventional homepage with Samsung and Android apps.

Leakster @evleaks posted another image on Twitter showing the BlinkFeed-style design with a dash of Google Now. The new UI seems to offer an at-a-glance feed of everything happening in the user's life, along with real world information such as your team's result or your flight time.

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It also seems to take a similar approach to the Tiles style on Windows Phone, offering instant information from different apps in their own block.

There have been other leaks, suggesting we'll see a refreshed S Health app, following the growing trend in health tracking apps and wearables. The design is flatter, which seems to be the message across all the leaks we've seen.

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The flatter design is also displayed in the latest leaked images of Samsung's S Voice, which was revealed by SamMobile. The S Voice functionality is said to have been improved for greater speed in voice recognition and the settings are also said to have changed.

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An invite to the company's live stream from MWC has also hinted at a new TouchWiz design for the Galaxy S5. The invite was posted by Samsung Mobile's global channel on Twitter and matches previous leaks of the interface.

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It's been reported that Samsung is aiming to move its TouchWiz user interface closer to that of stock Android and some of the designs suggest that. It looks less like Samsung and slightly more evolved. 

Conclusion

The rumours are in full swing and we expect we will be seeing plenty more in the coming weeks, especially with a February unveiling on the cards. There have been no image leaks of the device itself so far and therefore it is hard to determine exactly what it will look like, although a metal casing and redesign seems likely.

We also expect the display resolution to increase, and the camera be improved along with the speed of the device itself with a more powerful processor.

For now, it's a waiting game. We will update this feature as more rumours come to light.

READ: Best smartphones to look forward to in 2014