Samsung Galaxy S2's beefed-up 4G LTE version, Celox -- which first reared its head in Korea -- is back in the limelight.

Though the Celox apparently resembles the S2, it differs in many ways and represents a serious beefing up of the specification for the Galaxy family. Celox could emerge as another top competitor for iPhone 5, which is rumored to be launched either in September or October.

The arrival of such a piece from Samsung -- even though it is released in Korea -- is a cause of concern for Apple, which is yet to release its iPhone 5.

Until now, the iPhone 4 was a generation behind Android superphones like the Galaxy S2 and HTC Sensation, but the appearance of Celox reveals that Apple has a new breed of bigger and faster Android phones to counter.

Now the smartphone competition is about to get a lot tougher with Samsung Celox locking horns with iPhone 5.

Let's see below the speculated features of both iPhone 5 and Samsung Celox, which is expected to be released on the SK Telecom network in Korea.

iPhone 5

The iPhone 5 is expected to run on an upgraded operating system, iOS 5, and supported by a strong ecosystem including iCloud, which will store photos, apps, calendars and documents without storing them onto the phone's memory storage.

Apple is expected to release iPhone 5 as a World Phone - both GSM and CDMA compatible. It is conjectured that the phone will have a SIM-less design with 3-4 antennas. Another rumor suggested that the iPhone 5 will feature a SIM card slot for other countries except the U.S. This will allow users to insert any SIM card in iPhone when traveling abroad.

Apple has made improvements in the camera department by fitting a 5-megapixel camera with LED flash. Apple's iPhone 5 is expected to sport an 8-megapixel camera.

There is also near-unanimity in gadget circles that Apple will bring its A5 chip on to the iPhone 5. The A5 processor is the same one that Apple rolled out to power its iPad 2. Apple may boost the speed of its A5 chip in the range of 1.2 or 1.5 GHz as several Android smartphones are coming with 1.2 GHz processor.

Apple may fit a near-field communication chip in the iPhone 5 as some high-end Android devices are expected to sport the NFC chip. NFC allows for simplified transactions, data exchange and connections with a touch. A smartphone or tablet with an NFC chip could make a credit card payment or serve as keycard or ID card.

Apple is rumored to increase the screen size of iPhone 5 to compete with Android smartphones, probably going for a 4-inch screen. The iPhone 4 has a 3.5-inch screen.

Samsung Celox:

Samsung Celox is expected to come pre-installed with Android Gingerbread and sport a giant 4.5-inch Super AMOLED display with 800x480 screen resolution.

It is also surmised that the phone will have an 8MP rear-facing autofocus camera with LED flash and a 2MP front-facing camera. The device would feature Samsung's TouchWiz 4.0 UI.

Celox is expected to be powered by a 1.5GHz dual-core Qualcomm Snapdragon APQ8060 processor, which has the capability to support a 16MP camera and the ability to capture and display 1080p stereoscopic 3D video or 8 megapixel stereoscopic still images.

The phone, though, is a tad heavier compared to the Galaxy S2. Celox reportedly weighs 4.5 ounces and is 0.36-inch thick. It is also due to be fitted with a 1750 Li-ion battery.

In addition, the phone comes with an internal memory of 16GB and can be expandable up to 32GB with a microSD card.

Since the 4G LTE compatible Celox offers 800MHz LTE support, it may be initially targeted at Europe as both U.S. carriers Verizon and AT&T support only 700MHz LTE. But a different version of Celox could be launched in the United States.