INTRODUCTION
* Long Term Evolution (LTE) starts from 3GPP release 8
* 3GPP Technical Report 25.913 defines the key objectives of LTE as:
o support for a flexible transmission bandwidth up to 20 MHz
o peak downlink data rate of I00 Mbps when using 2 receive antenna at the UE
o peak uplink data rate of 50 Mbps when using 1 transmit antenna at the UE
o round trip time of less than 10 ms
o downlink average spectrum efficiency improved 3 to 4 times relative to release 6 HSDPA
o uplink average spectrum efficiency improved 2 to 3 times relative to release 6 HSUPA
* LTE has a flat architecture which minimize the number of network elements
* LTE is optimized for Packet Switched (PS) services but includes functionality to handle Circuit Switched (CS) services, e.g. CS
fallback to UMTS
* LTE supports the speech service using Voice over IP. Otherwise, the speech service can be supported by allowing the UE to fallback to
UMTS, GSM or CDMA2000
* LTE supports Multimedia Broadcast Multicast Services (MBMS) for the transmission of mobile TV
* Frequency Division Duplex (FDD) and Time Division Duplex (TDD) versions of LTE have been standardize. Both allow channel
bandwidths of up to 20 MHz
* LTE allows inter-working with existing GSM, UMTS and CDMA2000 technologies
* LTE uses QPSK, 16QAM and 64QAM modulation schemes with OFDMA (downlink) and SC-FDMA (uplink) multiple access
technologies
* LTE supports Multiple Input Multiple Output (MIMO) antenna technology in the downlink direction. 3GPP releases 8 and 9 do not
support MIMO in the uplink direction
* Existing spectrum allocations can be re-farmed for the introduction of LTE
* LTE simplifies network planning by minimising the requirement for manually planned neighbour lists
* LTE includes Self Organising Network (SON) functionality to help automate network configuration, optimisation, fault finding and
fault handling
* LTE Advanced starts from 3GPP release 10
* LTE Advanced introduces Carrier Aggregation to provide wider effective channel bandwidths. It also introduces MIMO in the uplink
direction, as well as increasing the number of antenna elements which can be used for MIMO in the downlink direction
* Other technologies continue to develop in parallel to LTE, e.g. UMTS introduces HSPA+ with MIMO, 64QAM and Multi-Carrier
Transmission allowing effective channel bandwidths of 10, 20 and 40 MHz
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