How we test Cell phones and smart phones

There's a lot more to cell phones than just the ability to make and receive calls. Today's mobile phones come with a plethora of features that include detailed address books, built-in digital cameras, instant messaging, speakerphones, MP3 players, streaming video, and Bluetooth connectivity.
There is no such thing as a typical cell phone.
Add a fully functional PDA and e-mail client, and you've got a smart phone. Phones come in a wide range of forms, from flip and candy bar styles to the slider and swivel designs. As a result, how each model performs and implements its features can differ substantially. Our testing is designed to provide a complete appraisal of the features and functionality of cell phones by examining usability (ease of use, feature sets, and so on), call quality (both subjective and comparative appraisals), and battery life.

Battery life

Talk time
When we conduct our talk-time battery life test, we start with a fully charged phone. The phone's display is set to a brightness level of 50 percent, and the backlight is set to turn off after 10 seconds. The phone's volume level is set to 50 percent. We call a landline and attach an earbud to the landline's receiver. The earbud is attached to an MP3 player, which plays a set of repeating audio files. We immediately begin recording the amount of time that passes until the phone's battery drains and it shuts off. We run this test multiple times until we have at least two sets of scores that are within 5 percent of each other, and we report the average.

MP3 playback time
When we conduct our MP3-playback battery life test, we start with a fully charged phone. The phone's display is set to a brightness level of 50 percent, and the backlight is set to turn off after 10 seconds. All phones are set to the same volume level, which we measure electronically to ensure fairness and consistency in testing. If the phone includes an EQ setting, we set it to "flat." We play a set of repeating audio files and record the amount of time that passes until the phone's battery drains and it shuts off. We run this test multiple times until we have at least two sets of scores that are within 5 percent of each other, and we report the average.