[custom:mwc15] Held each year in Barcelona, Spain, Mobile World Congress is one of the highlights of the mobile calendar, and 2015's show is no exception. In fact, we're set to see more high-profile Android launches than ever before at the 2015 MWC.

New flagship smartphones from Samsung and HTC wait in the wings. And we're also expecting wearables from LG, a big new Xperia tablet from Sony, and maybe even some surprises from Huawei.

The action kicks off on March 1, the day of many, many press conferences in Barcelona, before the show floor opens from March 2-5. Naturally, Android Central and Mobile Nations will have a sizeable presence on the ground, and we'll bring you full coverage all week.

But pre-event leakage has already given us a reasonably good idea of what to expect from MWC 2015. So let's take a look at what we're expecting...

Read More: The Android Central Mobile World Congress 2015 Preview

1. HTC

HTC  One M9

The HTC One M9

Online leakage in recent days has laid bare many details of HTC's next flagship smartphone, the HTC One M9. The successor to the M8 appears to sport a familiar design, now in a two-tone gold and silver color option in addition to gunmetal grey. Most recently the M9 was revealed in leaks from a German online store, and a noted Twitter leaker. It's a design we've been seeing hints of since the infamous "plaid pants" leak of January 2015 — so it seems reasonably likely that this is what we'll get on March 1.

HTC's appears to have mixed things up with a reflective trim on its new handset while keeping a darkened plastic area up top for RF visibility and infrared TV controls. What's more, it looks like the power key has finally been moved down onto the right edge of the phone.

Like the M8, the HTC One M9 reportedly sports a 5-inch display, front-facing "BoomSound" speakers (with Dolby Surround this time, a single 20-megapixel rear camera and HTC "Ultrapixel" front-facer. Moving the Ultrapixel shooter around the front should help out with low-light selfies, while an increased megapixel count for the main camera should greatly improve its capabilities in daylight, even if it results in a slight camera bump around the back.

HTC  One M9

As for specs, the rumors point to a Snapdragon 810 processor running the show, along with 3GB of RAM, an internal battery around the 2,900mAh, and 32GB of storage as a starting point, along with microSD expansion.

As is often the case, though, the hardware only tells part of the story. Video leaks have given us some hints as to what HTC's bringing to Sense 7, beyond the new italic clock widget seen in the press renders. The new Sense appears to have the ability to create UI themes based on your home screen wallpaper, and new tools in its Gallery app to combine photos in artistic ways.

It also looks like the HTC launcher can now create intelligent folders containing preset apps based on your location — for example, for work and home. And local restaurant suggestions appear to have made their way into the mix too.

Finally, there's the question of the mysterious fourth on-screen key seen in some M9 images but not others. Looking a little like a power/standby toggle. It's possible this is evidence of customizable soft keys on the upcoming device, but we're just not sure.

Wearables and tablets?

Bloomberg recently reported that HTC might announce its first wearable device alongside the M9 in Barcelona. Details are scant, but the report suggests HTC will integrate Under Armor's fitness technology into the device, suggesting a health-focused wearable.

HTC's bosses have also hinted at tablets being in the works as far back as late 2013. With a new release cycle approaching, rumors have started to swirl suggesting HTC may re-enter the tablet market with a Nexus 9-like slate running its Sense software. Will MWC be the place to show off such a device? We'll have to wait and see.

When and where

HTC's MWC press conference kicks off on March 1 at 4pm CET (3pm GMT, 10am EST, 7am PST.) Follow along with our liveblog right here on Andriod Central.

2. Samsung

Samsung Galaxy S6

The Samsung Galaxy S6

Samsung managed to avoid any major leaks of its next big thing until recently, but that doesn't mean it hasn't been teasing the Galaxy S6 all over the place.

Teasers from each of the main U.S. carriers show a device with a wraparound display, similar to the Galaxy Note Edge, if perhaps a little less edgy. The teasers also seem to reveal a metal-banded design, which would make sense given Samsung's design movements towards the end of 2014.

And Samsung's certainly dropping hints in that direction in its official teaser videos: "Tomorrow, metals will flow. Beauty will be powerful. Borders will disappear. Reflections will be free. Colors will leap. The future will be the present."

Recently leaked images from XDA give a tantalizing glimpse of a device which could well fit that bill. One model shows a wraparound "edge screen", along with Samsung branding and a curved metal trim. Around the back is the company's trademark sensor rig, to the right of the camera module.

As for the internals, much has been made of Samsung's alleged decision to drop Qualcomm's Snapdragon 810 chip for the Galaxy S6, instead apparently opting to use its own 64-bit Exynos part. It's unclear what's behind this decision, though the rumor mill suggests thermal performance was a factor. In any case, using a homegrown processor would make the Galaxy S6 a more vertically-integrated product, while the chip's 14nm manufacturing process could give it the edge over Qualcomm's 20nm Snapdragon chip when it comes to power efficiency.

As for what Samsung's doing with all that power? We'll just have to wait and see.

New wearables?

Rumors have been circulating for the past few weeks of a new Samsung Gear smartwatch codenamed "Orbis." SamMobile recently claimed to a have details of the device, which it says will pack a circular display and a rotary bezel around the outside of its watchface. Rotating this ring, it says, will be used to control certain software functions like the music player, dialer and home screens.

It's a unique approach to a circular smartwatch, and one that may well draw comparisons with the Apple Watch's "digital crown." And given Samsung's history of aggressively refreshing its smartwatch lineup, we wouldn't be surprised to see a new wearable debut alongside the Galaxy S6 at this year's show.

When and where

Samsung Galaxy Unpacked 2015 kicks off on March 1 at 6:30pm CET. That's 5:30pm GMT, 12:30am EST, or 9:30am PST. Follow along with our live coverage right here on Android Central.

3. LG

LG Watch Urbane

The LG Watch Urbane

As it often does, LG has already blown the lid on its MWC announcements, days ahead of the show. For AC readers, the star of the show is the LG Watch Urbane (don't call it a G Watch), a new Android Wear smartwatch with a sharper focus on design. Based on the design (and internal hardware) of the LG G Watch R, the Urbane brings an all-metal design to the table, with gold and silver models shown thus far.

There's also an LTE version on the way, with NFC payment capability, three physical buttons and LG's own proprietary software in place of Android Wear.

All we've seen of the LG Watch Urbane so far is promotional images, so we're eager to get our hands on this most desirable of wearables in Barcelona.

New mid-tier phones with Lollipop

LG's also set to show off its new line of entry-level and mid-range phones running Android 5.0 Lollipop, the Magna, Spirit, Leon and Joy. Not as exciting as a new high-end phone, but it'll be interesting to see how LG's adapted its Lollipop UX to run on less powerful hardware.

4. Huawei


More Honor

Huawei's just kicking off its new "Honor" brand in Europe, and we've already seen devices like the Honor 6 and Honor 6 Plus make waves internationally. We're not expecting a new Huawei flagship for another couple of months — instead the Chinese company will likely use MWC to fill out the rest of its lineup.

We're still waiting on news of Western availability for the Honor 6 Plus, and MWC would be a good platform to show off entry-level challengers like the Honor Holly.

Tablets and more?

Huawei's shown it's not afraid to get into the wearables space, with devices like the TalkBand B1. It's also been a while since we've seen any premium tablet hardware from the company, and given its growing global reach we wouldn't rule out new stuff in either product category.

When and where

Huawei will hold its Mobile World Congress press conference at 3pm CET. That's 3pm GMT, 10am EST, or 7am PST. Follow along with our liveblog to find out what's new.

5. Sony

Sony logo

Xperia Z4 Tablet

Xperia Z4 Tablet

There's no Sony press conference scheduled for this year's Mobile World Congress, but the Japanese manufacturer may have already let one major announcement slip ahead of the show. A listing that appeared briefly in the Xperia Lounge app before being pulled lists a "stunning 2K display," "the latest ultra-fast processor" and "industry leading battery performance."

Given the lack of "Compact" branding, there's a good chance we're looking at a larger form factor tablet — a successor to last year's Xperia Z2 Tablet, which sported a 10.1-inch display. Given that Sony has always used Qualcomm Snapdragon processors in its high-end products, we'd put money on that "ultra fast processor" being the latest 64-bit Snapdragon 810.

It's also likely Sony will show off new devices in the Xperia E4 series, but we're not expecting the next Sony flagship — likely the Xperia Z4 smartphone — until later in the year.

When and where

Sony doesn't have a press conference scheduled at this year's MWC, however the recent Xperia Tablet Z4 leak suggests an announcement by March 3.

6. How to follow along

You'll find all our MWC 2015 coverage on our Mobile World Congress landing page, which will be constantly updated throughout the week. You'll also find all the big announcements as the happen over on the Android Central main page. And don't forget to drop by the forums for discussion on the new devices as they're officially announced!

What are you looking forward to the most from Mobile World Congress 2015? Hit the comments and let us know!