Samsung has unveiled two versions of its next flagship phone Galaxy S6, one of which has a screen that curves round its sides.

The Galaxy S6 Edge uses the feature to provide a quick way to stay in touch with select contacts, and to alert owners to important information.

It will be sold for a higher price than the standard S6, which otherwise has the same specifications.

Samsung lost market share to Apple and others after the S5 sold fewer copies than its predecessor in many countries.

Its replacements were unveiled in Barcelona, ahead of the start of Mobile World Congress.The MWC will take place from March 2 to 5.

The new phones will go on sale on April 10 in 20 countries.

Samsung said it had set out to address past “missteps”, and had codenamed the devices “project zero” to reflect the need for a rethink.

Changes include making the TouchWiz user interface simpler to use by cutting the number of pop-up messages and introducing a metal frame and glass back instead of the plastic styling of earlier models.

The redesign has, however, meant some features have had to be jettisoned: the phones are not water-resistant, they do not have a microSD slot for extra storage and their backs cannot be removed to change their batteries.

The three topics Samsung is focusing on are:

• Revamped designs, including the premium model’s curved screen
• Camera upgrades
• In-built support for wireless charging, with support for two rival standards

The S6 Edge uses its curves to provide a couple of services.

The first is called People Edge, which provides a quick way to bring up calls, texts and other messages from five acquaintances of the owner’s choosing. Each person is assigned a different color, which the phone’s edge flashes when it rings, providing a hint of the caller’s identity even if the device is face down.

The second is Information Stream, which displays the time, weather and selected notifications on the curved part.

It appears Samsung has deliberately kept the functionality more basic than on its Galaxy Note Edge – a larger handset whose screen curves only around one of its sides. The older phone uses the extra space to both run apps of its own and to add controls to other apps.

The S6 phone’s front camera has been upgraded to five megapixels, while the rear one stays at 16MP.

Both gain from a wider aperture, which should improve their ability to take photos and videos in low light conditions.

Samsung has also taken steps to make the camera quicker to use, saying it now takes less than a second to double tap the home key and snap a shot.

The South Korean company is claiming a “world first” by embedding support for both the PMA and WPC’s Qi wireless charging standards.

The Android-powered handsets are also faster to recharge, and should return to 50% battery strength within half an hour of being plugged in.

Samsung said that this was half the time it would take to charge an iPhone 6.

Other improvements over the S5 include:

• Increased screen resolution – now 577 pixels per inch – and the ability to go 20% brighter
• A new 14 nanometre processor designed by Samsung, rather than bought from Qualcomm, that should be more energy efficient
• The addition of Samsung Pay, a smart wallet service that allows the handsets to act as a credit or debit card when tapped against a shop’s NFC chip reader or used to transmit magnetic stripe data. It will initially be limited to the US and South Korea

Samsung also revealed it had developed a new version of its Gear VR virtual reality kit that uses the S6 models as a screen.

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