3rd & 4th Generation mobile networks

Definition of "3G"

3G, or Third Generation, is a somewhat generic term for network technologies that the ITU classifies as part of their IMT-2000 specification. Generally, wireless network technologies must be able to provide a mobile device with a downlink connection speed of 384kbps in order to be considered a 3G technology. The most used 3G technologies are WCDMA, CDMA 1xEV-DO, and, technically, EDGE and CDMA 1xRTT.

Definition of "4G"

4G is the term used to refer to the next wave of high-speed mobile technologies that will be used to replace current 3G networks. The two top contenders are LTE and WiMAX, both of which are IP based networks that are built from similar, yet incompatible, technologies. Sprint and Clearwire are currently offering 4G WiMAX service in the USA, while Verizon and AT&T have committed to the use of LTE and are trialing their own 4G networks

"A2DP"

Definition of "A2DP"

The Advanced Audio Distribution Profile is a Bluetooth profile that allows for the wireless transmission of stereo audio from an A2DP source (typically a phone or computer) to an A2DP receiver (a set of Bluetooth headphones or stereo system). Such devices typically also support the AVRCP profile as well in order to allow for track selection and such. A common misconception is that A2DP support is available on all Bluetooth 2.0 devices,which is not the case, and that A2DP is only available on Bluetooth 2.0 devices, which is also not true. A2DP support can exist in older versions of Bluetooth, it just was not commonly supported.