Successor to 1G, the second-generation standards used digital radio signals. This meant that voice signals could be encoded and multiplexed, resulting in more data being squeezed over the airwaves. The voice quality improved considerably, and the kind of static heard on 1G networks is absent. The digital systems also emit lower power. Lower power means that the devices can be smaller, and that the towers become more inexpensive to set up and maintain.
2G networks comprise mainly TDMA and CDMA networks, depending on the type of multiplexing i.e. the way in which the multiple radio waves are combined into a single stream. TDMA standards can be further divided into GSM, iDEN, and more.