The Galaxy S II (S2), which went on to sell over 40 million units, built on the success of the original Galaxy S, which sold over 10 million units during 2010. It closely resembled the Samsung Infuse 4G phone which was announced as an exclusive for AT&T at the CES Show in January 2011. The Galaxy S II addressed some of the shortcomings of the original Galaxy S by adding a better screen (4.3-inch Super AMOLED Plus) and a camera LED flash.
The most impressive characteristic of the phone was its thinness. It was only 8.5 mm thick, weighing 116g while including a 1650 mAh battery and a dual-core 1 GHz processor. It was also one of the first Android phones to support for near field communications (NFC). The device came under close scrutiny from rivals when it was launched as they were perplexed by how Samsung could package such a fully featured phone into such a tightly designed form-factor.
The Galaxy S II became a strong seller for Samsung in 2011. The company proved increasingly adept at getting its devices ranged in every channel and combined this coverage with high-profile, high-impact marketing with the slogan "Vivid. Fast. Slim." to drive demand for the phone. When it launched in May 2011, it was available via more than 140 partners in over 120 countries and Samsung had pre-order sales of more than three million units.
In addition to its widespread success with consumers, there was also a clear focus by Samsung on making the Galaxy S II attractive to business users. It had unexpectedly unveiled a series of partnerships with companies focused on enterprise mobility solutions when the phone was launched. This echoed efforts by Motorola which was also trying to make Android devices more acceptable to business users. In a set of wide-ranging announcements, Samsung allied with Calgary Scientific, Cisco, Citrix, Sybase and its own SDS division to offer mobile healthcare, unified communications, virtualisation, messaging and business intelligence services. It also announced that the Galaxy S II would support 38 Microsoft Exchange ActiveSync IT policies. Although this was only a fraction of the policies supported by RIM's BlackBerry devices, it was a first step in getting more business users interested in using Android devices to connect to corporate networks.
This model is the SGH-T989 variant which produced for T-Mobile in the USA.
The T-Mobile variant differed from the "International" version of the Galaxy S II as it used a Qualcomm Snapdragon S3 (APQ8060) chipset rather than Samsung’s Exynos processor. The chip was changed so the device was able to support T-Mobile’s HSPA+ network and some specific US cellular bands.
It also had a slightly larger screen (4.52 inches) compared to the “International” variant (4.3-inches).
Furthermore, rather than the single clickable capacitive touch “home” button on the “International” variant, the T-Mobile S II had four capacitive touch buttons below the screen. It also supported NFC.