In telecommunications, 4G is the fourth generation of standards for mobile telephony corresponding to LTE-Advanced (IMT-Advanced). Following on from 2G, 3G and 3.5G (HSPA); it allows higher speeds of up to 3 Gbit/s in LTE-Advanced and 300 Mbit/s in LTE Cat 5 and 6. Its specifications are defined by the ITU and 3gpp. In practice, speeds range from 10 Mbit/s to 80 Mbit/s per user, depending on the number of users and the category of LTE terminals, such as LTE Cat 4 for 150 Mbit/s, LTE-A Cat 6 for 300 Mbit/s, LTE-A Cat 12 for 600 Mbit/s and the number of active users in the same radio cell, since the bandwidth is shared between the user devices.