How the iPhone Works

iPhone 3GS

Apple unveiled the iPhone 3GS at the 2009 World Wide Developers Conference (WWDC). The S stands for "speed." According to Apple, the iPhone 3GS is up to twice as fast as the previous iPhone 3G model. That applies both to accessing the data network and launching applications. In real-world tests, journalists found that the iPhone 3GS often was more effective at picking up 3G signals from the cell phone carrier than its predecessor.

But the iPhone 3GS isn't just faster than previous models. It also boasts some new features. Here's a rundown of what you'll find on the iPhone 3GS:


  • More storage space: There are two versions of the iPhone 3GS: 16 GB and 32 GB models. This doubles the capacity of older iPhone models. Both models are available in white or black.
  • Video camera: Not only does the iPhone 3GS's camera capture larger photos (3.2 megapixels versus the iPhone 3G's 2.0-megapixel camera), it can record video at 30 frames per second, too. The camera can focus automatically or you can use the touch screen to tell the camera where to focus the image. It also adjusts the image's white balance automatically.
  • Voice control: While many other phones on the market have voice dialing features, the iPhone 3GS's voice control extends the functionality to other parts of the phone. Not only can you make calls by speaking into your phone, you can also control music playback and other functions.
  • Compass: When paired with the accelerometer and GPS receiver, the iPhone 3GS's compass helps keep iPhone owners from getting lost. It also allows app developers the opportunity to develop augmented reality applications.
  • Oleophobic screen: One problem with touch screens is that they tend to attract smudges. The iPhone 3GS has an oleophobic screen. An oleophobic material repels oils, keeping the screen relatively smudge-free.
  • Tethering: If your cell phone carrier allows it, you can use the iPhone 3GS as a modem for your computer. Simply hook the iPhone 3GS to the computer using an Apple USB cord and you can surf the Web at 3G speeds. Some carriers don't allow tethering, including AT&T in the United States.

While these features were touted as impressive new technology, many of them already existed on other smartphones.

On the next page, we'll take a closer look at the iPhone 4.