Release 10 enhances the capabilities of LTE, to make the technology compliant with the International Telecommunication Union's requirements for IMT-Advanced. The resulting system is known as LTE-Advanced. This chapter covers the new features of the LTE-Advanced air interface, by focussing on carrier aggregation, relaying and enhancements to multiple antenna transmission on the uplink and downlink. We also discuss the techniques that are used to control interference in heterogeneous networks, in which the cells are on the same carrier frequency but have different sizes. Finally, we cover techniques for offloading traffic from the LTE network and for controlling the load from machine-type communications.
For the most part, the Release 10 enhancements are designed to be backwards compatible with Release 8. Thus a Release 10 base station can control a Release 8 mobile, normally with no loss of performance, while a Release 8 base station can control a Release 10 mobile. In the few cases where there is a loss of performance, the degradation has been kept to a minimum.
TR 36.912  is 3GPP's submission to the ITU for LTE-Advanced and is a useful summary of the new features of the system. The contents of Release 10 are also described in the relevant 3GPP release summary  and are reviewed in a regularly updated white paper by 4G Americas .
The ultimate goal of LTE-Advanced is to support ...