Third generation of mobile service, digital. It offers a convergence of voice, data and multimedia content, at rates of up to 2mbps. The International Telecommunications Union (ITU) has laid down some indicative minimum requirements for the data speeds that the IMT-2000 standards must support. These requirements are defined according to the degree of mobility involved when the 3G call is being made. As such, the data rate that will available over 3G will depend upon the environment the call is being made in:
High Mobility: 144 kbps for rural outdoor mobile use. This data rate is available for environments in which the 3G user is traveling more than 120 kilometers per hour in outdoor environments. Let us hope that the 3G user is in a train and not driving along and trying to use their 3G terminal at such speeds.
Full Mobility: 384 kbps for pedestrian users traveling less than 120 kilometers per hour in urban outdoor environments.
Limited Mobility: At least 2 Mbps with low mobility (less than 10 kilometers per hour) in stationary indoor and short range outdoor environments These kinds of maximum data rates that are often talked about when illustrating the potential for 3G technology will only therefore be available in stationary indoor environments.