g 2015. Release 12 was completed in 3GPP in March 2015 and the deployments are expected by 2017. Release 12 includes dual connectivity between macro and small cells, enhanced CoMP (eCoMP), machine-to-machine (M2M) optimization and device-to-device (D2D) communica- tion. Release 13 work started during second half of 2014 and is expected to be completed during 2016. Release 13 brings Licensed Assisted Access (LAA) also known as LTE for Unlicensed bands (LTE-U), Authorized Shared Access (ASA), 3-dimensional (3D) beamforming and D2D enhancements. Introduction 3GPP Release Commercial deployment Figure 1.5 3GPP Release availability dates The timing of 3GPP releases in standardization and in first commercial networks is shown in Figure 1.5. The main contents of each release are summarized in Figure 1.6. The radio data rate has increased very fast with LTE and LTE-Advanced and 150 Mbps was available with Release 8 commercially during 2010 when using continuous 20 MHz spectrum allocation and 2x2 MIMO. The carrier aggregation with 10 + 10 MHz during 2013 enabled 150 Mbps also for those operators having just 10 MHz continuous spectrum. The aggregation of 20 + 20 MHz during 2014 pushed the peak rate to 300 Mbps and three-carrier aggregation (3CA) further increased the data rate up to 450 Mbps during 2015. The evolution is expected to continue rapidly in the near future with commercial devices supporting 1 Gbps with 100 MHz of total bandwidth. The evolution of device data rate capabilities is illustrated in Figure 1.7. The terminals used to be the limiting factor in terms of data rates but now the limiting factor is rather the amount of spectrum that can be allocated for the connection. Those operators having more spectrum resources available will have an advantage in terms of data rate capabilities. The carrier aggregation aspects are discussed in Reference [2]. 1.5 LTE Spectrum The LTE-Advanced needs lot of spectrum to deliver high capacity and data rates. The typical spectrum resources in European or some Asian markets are