LTE UMTS

UMTS air interface is based on DS CDMA , that is, user data bits are multiplied with a spreading sequence (consists of random bits called chips) and chip rate is much higher than symbol rate or data rate. This process spreads the user data signal to wider frequency band.

There are four interfaces connecting the UTRAN internally or externally to other functional entities: Iu, Uu, Iub and Iur . The Iu interface is an external interface that connects the RNC to the Core Network (CN). The Uu is also external, connecting Node B with the User Equipment (UE).

UMTS relies on a packet-switched system . This allows cellular devices to send small “packets” of data to a destination, whereas circuit-switched networks require a point-to-point connection. In an old phone network, making a call meant reserving a line between the sender and receiver.

UMTS is the standard for 3G or third generation communications . LTE is the standard for the 4G or fourth generation standards . Data Rate. UMTS is an extension to 2G and offered better data rates compared to the 2G network. This employed packet switching which increased the speeds to a greater extent.