The strongest iPhone 5 rivals -- Samsung Galaxy S2 and Motorola Droid Bionic -- have came to the United States after several changes in terms of design.

Galaxy S2, which runs on Android 2.3 Gingerbread OS and sports Samsung's TouchWiz UI, came to Sprint's network on Friday as Samsung Epic 4G Touch version, while AT&T would launch Galaxy S2 version on Sept. 18.

The Samsung smartphone comes with an 8-megapixel camera with flash and can record HD video in 1080p offering the richest video content on a smartphone. The phone also has the front-facing 2-megapixel camera for video chat.

Motorola Droid Bionic has undergone several changes in terms of design. At the beginning of this year, it looked like the Motorola Atrix but now looks very similar to the Motorola Droid 3, one of the latest high-end phones. However, the Motorola Droid 3 has a slider QWERTY, unlike the Droid Bionic that is just a touchscreen phone.

Other changes for the Droid Bionic includes higher RAM capacity, change in chipset from the Tegra 2 AP20H to the TI OMAP4430 and surprisingly the inclusion of lesser battery capacity compared to the one introduced in the beginning.

As for Apple Inc.'s iPhone 5, most features are attributed to the realm of rumors but some are more likely to be in the phone than others. For sure, the iPhone 5 will feature the latest iOS 5 operating system, the A5 processor found in the iPad 2, an 8-megapixel camera and a slimmer and thinner design.

Apple's iPhone 5 is seeing “unprecedented demand” ahead of its release, which is rumored to come in October, according to a recent survey conducted by RBC Capital Markets. The data showed that 31 percent of the respondents were very/somewhat likely to buy the iPhone 5, significantly exceeding the pre-launch iPhone 4 demand of 25 percent.

In the second half of 2011, the heated battle will be between Apple iPhone 5, Samsung Galaxy S2 and Motorola Droid Bionic. All these three smartphones are right up there in the hype clouds, and hopefully they can live up to it.

Here is a look at 10 reasons why Galaxy S2 and Motorola Droid Bionic will score over the iPhone 5.

Processing Power: The Sprint and AT&T version of Galaxy S2 is equipped with dual-core 1.2 GHz ARM Cortex-A9 Mali-400MP GPU Orion chipset, while the T-Mobile version will be powered by a 1.5 GHz dual core Qualcomm APQ8060 processor. It is backed by 1 GB of RAM.

The Droid Bionic offers the TI OMAP4430 chipset, clocking in at 1 GHz, which uses dual-core ARM Cortex-A9 with a PowerVR SGX540 integrated 3D graphics accelerator that runs at a clock frequency of 304 MHz. And it comes with ARM-Cortex A9s with ARMs SIMD engine (Media Processing Engine, aka NEON) which may have a significant performance advantage in some cases over Nvidia Tegra 2s Cortex-A9s with non-vector floating point units. And there is a dual-channel LPDDR2 memory controller compared to Nvidia Tegra 2s single-channel memory controller.

Meanwhile, the iPhone 5 is expected to come with the iPad 2's A5 processor but it is doubtful if it would exceed the 1.2 GHz barrier. With improved versions of Galaxy S2 about to feature 1.5 GHz processor with 3D graphics support, iPhone 5 needs more to match up to Samsung’s flagship phone.

Apple’s A5 processor has a dual-core ARM Cortex-A9 CPU with NEON SIMD accelerator and a dual core PowerVR SGX543MP2 GPU. Apple lists the A5 to be clocked at 1 GHz on the iPad 2's technical specifications page, though it can dynamically adjust its frequency to save battery life.

Operating System: Apple's iPhone 5 is expected to come equipped with the recently announced iOS 5. The important features of iOS 5 are already found in Android, except iMessage that is copied from RIM's BlackBerry. The iOS 5 important features include the notification bar, cloud synchronization, wireless syncing, Twitter integration and Widgets.

The Galaxy S2 and Motorola Droid Bionic comes equipped with Android 2.3 Gingerbread OS. In recent days, Android 2.3 Gingerbread OS is used in smartphones and Android 3.0 Honeycomb OS is used in tablets.

But the next version of Android called Ice Cream Sandwich will be a single OS running across smartphones and tablets. Google's executive chairman Eric Schmidt confirmed in an interview with Marc Banioff at Salesforce.com’s conference, Dreamforce, in San Francisco, about the rumours of Ice Cream Sandwich, which was previewed at a Google conference in May.

We have a new operating system, internally known as Ice Cream Sandwich for some reason, which is being released in October or November, which everyone is really excited about, Schmidt said.

In addition, the entire Android OS is an open source system, which has inspired increased transparency and liberty. Being made publicly available enables anyone to copy, modify and redistribute the source code without paying royalties or fees.

Anyone can get access to the source of Android to better the system. This is also a double-edged sword, in the sense that it allows those will less-than-ideal intentions to discover any weakness of the phone. But that can be seen as an indirect plus because when weaknesses are found in the open source community, they are quickly fixed. The same thing cannot be expected of the iPhone 5.

Design: Apple's iPhone 5 will be just an upgrade of its previous versions. On the other hand, the delay of Galaxy S2 and Droid Bionic in reaching the U.S. shores showed that Samsung and Motorola prepped various designs with improved modifications and specs with different carriers.

Sprint unveiled its Galaxy S2 version known as Samsung Galaxy S2 Epic Touch 4G, which retains all the basic specifications of the Galaxy S2, except for the 4.5-inch display.

The AT&T version of Galaxy S2 will retain the 4.3-inch display, whereas the T-Mobile version has not received any official name, but the Hercules is expected to come along with 4.5-inch screen.

Verizon confirmed that it will not be offering the Galaxy S2 on its network, but would opt for Samsung Droid Prime to grow its Long Term Evolution lineup. In fact, according to Boy Genius Report, Verizon is worried that the Galaxy S2 will not be able to compete with the iPhone 5 when it is launched.

Hence Verizon is expecting Droid Prime to become its ultimate Android flagship phone which will most likely be the first phone to feature Android Ice Cream Sandwich OS, giving stiff competition to the iPhone 5.

Droid Bionic has undergone several changes in terms of design. It looked like the Motorola Atrix at the beginning of this year, but now looks very similar to the Motorola Droid 3, one of the latest high-end phones launched by Motorola. But the Motorola Droid 3 has a slider QWERTY, unlike the Droid Bionic that is just a touchscreen phone with a 4.3-inch screen.

Display: Motorola's Droid Bionic uses a qHD (540 x 960 pixels, 256 ppi pixel density) TFT display for its 4.3-inch screen, while Samsung Galaxy S2 uses Super AMOLED Plus display.

Galaxy S2 will be coming to AT&T with a 4.3-inch screen, while the T-Mobile and Epic 4G Touch version of Sprint has 4.52-inch display screen. The Epic 4G Touch comes with 4.52-inch (about 206 ppi pixel density) 800 x 480 pixels Super AMOLED Plus capacitive touchscreen display.

The Apple iPhone 5 is expected to feature a 3.7-inch or 4-inch display according to different case designs. At a minimum of 4.3 inches, the display of Galaxy S2 and Droid Bionic dwarfs the upcoming iPhone 5. With major smartphone manufacturers opting for 4.3 inches as the ideal screen for their phones, it will be interesting to see what comes out on the new iPhone 5.

Flash: Flash is considered as a big advantage an Android systems holds against iPhone. Flash enriches Web experience. Any Flash player has to be able to animate on top of video renderings, which makes hardware accelerated video rendering at least not as straightforward as with a purpose-built multimedia player.

Therefore, even when only displaying video, Flash players are more resource-intensive than a dedicated video player software. Presently for Apple, only Mac OS 9/X supports Flash.

The Galaxy S2 and Droid Bionic supports Flash. The Galaxy S2 supports full HD video playback inside Adobe Flash player. There is no other device at present which allows full HD video playback even inside Adobe Flash player.

According to Apple, Adobe Flash is a big security risk, not to mention it crashes lots and kills your battery life. Rather than using Flash, Apple has adopted HTML5, CSS and JavaScript – all open standards. Apple’s mobile devices all ship with high performance, low power implementations of these open standards.

Recently, Adobe said Flash will come to Apple Inc.'s iPad, iPhone, iPod Touch, not directly supported but just that the new app tools will be able to export Flash content as an HTML5-supporting format.

At the IBC 2011 Conference and Exhibition, Adobe announced the releases of the new streaming video solutions, including Adobe Flash Media Server 4.5 and Flash Access 3.0 software.

The new releases works for publishers, who want videos stored in Flash to be visible on popular Apple products such as iPhone, iPod and iPad. For a recurring fee of $4,500, Adobe Flash Media Server 4.5 software converts website video stored in Flash so it can be seen on Apple handhelds, in an Apple-friendly format called HTTP Live Streaming, according to the Daily Mail.

Connectivity: Galaxy S2 already supports 3G data speeds up to 21 Mbps (HSPA + networks), but with the Galaxy S2 LTE version poised to feature HSPA up to 42 Mbps, the iPhone 5 doesn’t stand a chance in terms of speed.

In addition, the Galaxy S2 smartphone will get the 4G treatment, offering data speeds up to four times faster than what is expected in Apple's forthcoming iPhone 5.

Many reports and rumors show that 4G capable iPhone 5 is on the way, but in fact it may be 4G supported through AT&T network and most probably not the Verizon’s LTE. Presently, Verizon’s LTE network is still being built and AT&T’s is still being planned. Even if iPhone 5 comes with a 4G title, the users will not have access to 4G network initially whether it’s built or not.

According to a research note from Hudson Square analyst Todd Rethemeir, the iPhone 5 due this fall will support HSPA+ technology, a development that will allow the device to offer faster data speeds on GSM networks such as AT&T. The present iPhones are shipped with standard HSPA.

Even though HSPA+ is slower than the LTE standard, AT&T has begun marketing its HSPA+ network as 4G, meaning that the carrier could position the next iPhone as a 4G device despite it failing to offer LTE compatibility.

On the other hand, Droid Bionic will feature the has 4G LTE network, but it offers tired data plan which limits the consumer's data consumption. According to Nielsen Co.'s analysis, data hungry consumers are on rise.

Battery and Memory: Galaxy S2 and Droid Bionic has the privilege of expandable memory and a removable battery. Apple's iPhone versions differ from other smartphones in the market in terms of removable storage as none of them have featured one.

In terms of RAM memory, Apple never reveals its capacity and it always turns out to be less than other phones. Hence, the Galaxy S2 holds the advantage of 1 GB RAM to match the dual core processor.

If the iPhone 5 does feature 4G support, then that alone will reduce the battery life of the iPhone 5 to less than 8 hours. Galaxy S2's battery life is not the best on the face of the planet, but it easily lasts a day with good use and can stretch out to two days with mostly calls and texting.

If the Galaxy S2 was used all the time then a user will be lucky to get 10 hours of battery and that's with the enhanced 1650 mAh battery widget on board, according to Techradar.com review.

To support the high-end Motorola Droid Bionic there is a whopping 1735 mAh battery which should give enough power to keep the phone running for a longer period.

Droid Bionic has received an upgraded RAM memory of 1GB of DDR2 from 512 MB RAM featured during the beginning of this year. The Motorola smartphone also has 2 GB ROM support along with 1 GHz of dual core processor.

Camera: Droid Bionic and Galaxy S2 comes with 8-megapixel rear-facing camera with flash and can record HD video in 1080p while iPhone 5 is sure to feature similar sized camera, according to Bloomberg.

But the ability to capture video at 1080p is yet to be confirmed for the iPhone 5. And the quality camera pictures in Droid Bionic and Galaxy S2 seem to be outstanding as photos taken by it appears in various tech Web sites. The photos look pleasing with sharpness, color accuracy and brightness.

The iPhone 5 picture clarity can never be disputed, hence the three phones stand toe to toe here.

Security: The approaches for Android and iOS security are different. Apple verifies all the apps before allowing it onto App Store to prevent a virus, but the rest of the phone is semi-vulnerable. Although Android does not check the apps, the apps are run in an isolated way so as not to affect the system in the event of a virus attack.

According to a recent Symantec report, even though iOS and Android both have their weaknesses, the mobile platforms are still much more secure than their PC counterparts.

Researchers have found many more vulnerabilities on iOS than Android. Roughly 200 have been found on iOS, compared to only 18 found on Android. Only 4 of those 18 remain unpatched by Google. Google is also faster than Apple when it comes to patching a vulnerability, averaging 8 days to Apple's 12 days.

Both the operating systems are vulnerable to viruses, but the Android has an antivirus app which iOS does not have. Hence Galaxy S2 and Droid Bionic holds an advantage over the iPhone 5.

Apps and open source: The Android market has improved in quality and quantity over the past few years and is expected to surpass the App store. The biggest plus point about Android apps is that majority of the quality apps are free.

Android Market is an online software store developed by Google for Android OS devices. Anyone can get access to the source of Android to better the system. If any weaknesses are found in the open source community, they are quickly fixed.

Though Apple's iOS is not an open source, 200 million users have downloaded over 15 billion apps from Apple's App Store. As of May 2011, Apple approved its 500,000th app.

After the success of Apple's App Store, and the launch of similar services by its competitors, the term app store has been adopted to refer to any similar service for mobile devices. However, Apple applied for a trademark on the term App Store in 2008 which was tentatively approved in 2011.

The iPhone 4 was criticized for antenna-gate issues. Apple said the device’s antenna issues were related to software and not the hardware, eliminating the need to recall the device, but it took months to resolve the issue.

Conclusion: Despite the fact that Apple is facing major competition from smartphones running on Android OS such as Samsung Galaxy S2 and Motorola Droid Bionic, iPhone 5 remains the most anticipated smartphone in the U.S. market. iPhone 5 will appeal to both masses and critics as Apple is known for producing cool devices.

Meanwhile, consumers look at branding as an important value-added aspect of products or services, as they are expected to come with a certain attractive quality or characteristic. Apple has now become the world's most valuable brand, and the iPhone 5 is sitting on the glories of its predecessors, according to a study published by the global research agency Millward Brown.

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