(Evolved Packet System). EPS is composed of E-UTRAN (Evolved UTRAN) and EPC (Evolved Packet Core) which are commonly known as 3G-LTE (Long Term Evolution) and SAE (System Architecture Evolution) respectively. E-UTRAN is focused on the evolution of the Radio Access Network while EPC looks into the future needs of the core network. EPS is defined primarily in 3GPP Release 8 which was completed in December 2008. Chapter 3 primarily focuses on E-UTRAN as defined in Release 8, its performance aspects and its evolution. The second section looks into the different releases of 3GPP while the third and fourth sections describe the LTE objectives and LTE air interface respectively. Layers 1-3 are described in Sections 5-7 whereas the key attributes of LTE are listed in Section 3.8. EPS overall architecture and test results are presented in Sections 3.9 and 3.10 respectively. The roadmap of LTE, industry outlook and summary of the chapter are presented in Sections 3.11-3.13 respectively. 3.2 3GPP Releases The evolution of GSM systems has been standardized by 3GPP in several releases, starting from Release 1999 (R99) and moving towards Release 4 (Rel-4), Release 5 (Rel-5) all the way to Release 10 (Rel-10). Each release primarily corresponds to a new radio access technology, but not always, as can be witnessed from Figure 3.1. These releases also include enhancements to the previous radio technologies and to the rest of the network that were introduced in the earlier releases. This section will highlight some of the key features that have been introduced from Rel-99 to Release-7. Enhancements that are part of Rel-8 and Rel-9 are discussed in Section 3.3 3GPP LTE while Rel-10 enhancements are discussed in the Section 3.10 3GPP Roadmap Evolution: Next Generation Mobile Communications Ecosystem: Technology Management for Mobile Communications Saad Z. Asif © 2011 John Wiley & Sons, Ltd. ISBN: 978-0-470-74746-9 DL: 1.0 Gbps UL: 1.0 Gbps LTE-Adv 3GPP Rel 10 DL: 100 Mbps UL: 50 Mbps 3GPP Rel 9 Mar-2011? HSPA+ DL: 100 Mbps UL: 50 Mb