mobile communications. With LTE, these advances were combined with the advanced design of the multiple access technology enabling both efficient terminal power consumption with Single Carried FDMA (SC-FDMA) for uplink and low-complexity terminal receiver with Orthogonal Frequency Division Multiple Access (OFDMA) for downlink. The improvements in Release 9 did not change the peak data rates or key physical layer principles or the achievable data rates. Release 9 improvements mostly focused on enabling voice service, including necessary elements for the emergency calls such as prioritization and position location. 2.2.1 Releases 8 and 9 Physical Layer The LTE Releases 8 and 9 support six different system bandwidths ranging from 1.4 to 20 MHz as shown in Table 2.1. The design has been done such that the timing is constant for all bandwidths, only the number of sub-carrier to receive by the UE changes as the function of the bandwidth. The designs for the synchronization signals as well as for the Physical Broadcast Channel (PBCH) are such that they are included in the six centre 180 kHz physical resource blocks regardless of the actual system bandwidth. The downlink resource allocation is done with the Physical Resource Blocks (PRB), with the minimum resource allocation being one resource block. A resource block is 1 ms in time domain and 12 sub-carriers, each of them 15 kHz, thus 180 kHz in frequency domain. The number of OFDMA symbols fitting to a sub-frame depends on the cyclic prefix length chosen. With the short cyclic prefix, there is room for 14 symbols per each sub-frame while longer (extended) cyclic prefix reduces the number of symbols to 12. The downlink PRB structure is shown in Figure 2.1. The eNodeB scheduler will allocate the resources every 1 ms among the devices needing to the scheduled. The downlink frame structure is using 1 ms sub-frame with 1, 2 or 3 symbols used for downlink control signalling on Physical Downlink Control Channel (PDCCH) and rest of the sub-frame left for user data carried on Ph