From GSM to LTE: An Introduction to Mobile Networks and Mobile Broadband

4.14 LTE-Advanced (3GPP Release 10)

Most of the LTE functionality discussed in this chapter is specified in Release 8 of the 3GPP standard. Release 9 only contains minor improvements for LTE, one of the reasons perhaps being that the industry was still working on the implementation and deployment of the new system when work started on Release 9 and therefore first had to evaluate the performance of the new system. Major new features to comply with the IMT-Advanced requirements of the ITU are included in 3GPP Release 10 and are referred to as LTE-Advanced. The major goal of these enhancements is to further reduce cost and to further increase the maximum datarates per user. It should be noted at this point that at the time of publication of this book, and for a number of years afterward, it is unlikely that LTE-Advanced functionality will be used in the field. The following sections list some of the most important new features of Release 10 and 11. Details can be found in the 3GPP work plan [36] and the feasibility study for LTE-Advanced [37].

4.14.1 Latency Reduction

LTE-Advanced aims to further reduce control plane and user plane latency in the access and core network. As latency is already low, a further reduction is quite ambitious. The requirements are as follows:

• A reduced switching time from RRC Idle to RRC Connected state transfer in less than 50 milliseconds.
• While in RRC connected state, the UE should return from a dormant state to a fully active state in less than 10 ...