Abstract
The purpose of the current chapter is the presentation of the basic characteristics of the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) technology. With the rapid dispatch of LTE deployments and the upgraded mobile user experience that it delivers, LTE is clearly emerging as a successful technology for mobile communications. LTE features a simplified network architecture, higher performance and lower cost per bit. This chapter indicates the main characteristics and developments of LTE and a part is devoted mainly to system architecture. Furthermore, a description of the standardization process within 3GPP is provided. We will also introduce Release 10 (LTE Advanced), one of the leading technologies for next-generation mobile broadband. Currently 3GPP is in the closing stage of LTE Release 11. Thus, we will also perform a comprehensive comparison between the two Releases. Finally, an important issue that will be mentioned is the interworking of LTE with other technologies. The presented information will help readers to understand how LTE has evolved and the functionality of 3GPP technologies.
Top3. Lte-Advanced
3.1. Introduction
LTE-Advanced (LTE-A) is the evolution of LTE. Release 10 enhances some of the features introduced in Releases 8 and 9 (Table 1). LTE-Advanced meets the requirements of IMT-Advanced of ITU-R for the 4G of mobile technologies. LTE-Advanced is anticipated to be the radio-access technology submitted to ITU as the 3GPP candidate for IMT-Advanced radio access. 3GPP actions for LTE-Advanced have been published in 3GPP TR 36.912 and 36.913. Nowadays, 3GPP evolves to Release 12.
Table 1. Comparison between 3GPP Rel-8 and Rel-10
| Feature | LTE Rel-8 | LTE Rel-10 |
| Network Architecture | Very-flat, IP-based eNB, S-GW | Same as LTE Rel-8but there are certain differences for heterogeneous network architecture. |
| Access Technology | Downlink: Scalable OFDMA
Uplink: scalable SC-FDMA | Same as LTE Rel-8 but single-carrier property is not preserved for SC-FDMA uplink |
| Channel Bandwidth | 1.4, 1.6, 3, 5, 10, 15, &
20MHz | Additionally supports up to 100 MHz for downlink and 40MHz for uplink and 40MHz for uplink
with carrier aggregation |
| Spectrum | Licensed IMT-2000 bands | Licensed IMT-2000 bands |
| Total overhead | Downlink overhead
~31%–33% | Downlink overhead
25%–28% |
Key Terms in this Chapter
Quality of Service (QoS): Refers to a network’s ability to achieve maximum bandwidth and deal with other network performance elements like latency, error rate and uptime. QoS also involves controlling and managing network resources by setting priorities for specific types of data (video, audio, files) on the network. QoS is exclusively applied to network traffic generated for video on demand, IPTV, VoIP, streaming media, videoconferencing and online gaming.
Specifications: A detailed description of technical requirements, usually with specific acceptance criteria, stated in terms suitable to form the basis for the actual design development and production processes of an item having the qualities specified in the operational characteristics.
Backward Compatibility: A feature that guarantees functionality with previous standards or versions. Backward compatibility makes it possible for technology to move ahead without making existing technology obsolete.
ITU Radio (ITU-R): Ensures the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radio communication services, including those using satellite orbits, and to carry out studies and approve Recommendations on radio communication matters.
International Mobile Telecommunications-Advanced (IMT-Advanced): A standard and system created by the International Telecommunication Union (ITU), for the creation, operation and management of next generation mobile networks and Internet communications. It provides higher quality mobile data and communication services than its predecessor. IMT-Advanced is largely incorporated.
MIMO: A wireless technology that uses multiple transmitters and receivers to transfer more data at the same time.