Overview of LTE and LTE-Advanced New Features
As described in Section 1.1, the specifications of 3GPP systems are developed in releases. The first specification release for LTE was Release 8, and the focus in the early stage of standardization of the Release 8 specification was the completion of basic functionality. After that, new features for improvement were added in Release 8 and Release 9 until the end of 2009. However, even with these improvements, the Release 9 LTE system did not meet the requirement of a 4G system defined by the International Telecommunication Union (ITU). As a result, additional features were added in the Release 10 specification of LTE to meet the ITU's requirement. In essence, the LTE-Advanced system is a system that is backward-compatible with the LTE system and that meets the performance requirement of the ITU for a 4G wireless system. The specification for Release 10 was completed in the second quarter of 2010, and work on Release 11 is ongoing from February 2012.
This section provides a brief overview of the new features of LTE and LTE-Advanced. The following features are explained in the subsequent sections:
- Release 8: Voice over LTE (VoLTE), and Home eNB (HeNB).
- Release 9: Public Warning System (PWS), and Multimedia Broadcast/Multicast Service (MBMS).
- Release 10: Carrier Aggregation (CA), Relay, Minimization of Drive Test (MDT), enhanced Inter-Cell Interference Coordination (eICIC), and Machine Type Communication (MTC).