rce (frequency subcarrier and time slot) is allocated according to a user's need. For example voice communications may need a relatively small number of time slots in one carrier. In contrast a video streaming service may need to reserve mul- tiple subcarriers on a continuous time basis. This is illustrated in Figure 10.29, where different users (shades) are allocated different amounts of telecommunications resources. Such granularity and flexibility of resource provision is of great importance to data com- munication applications which have time-space variant transmission rate requirements. Because of these and a number of other reasons, OFDMA is the technology of choice for the 4G standards. Broadband Telecommunications Technologies and Management (subframes) Frequency (subcarriers) Figure 10.29 Diverse capacity resource allocation to users in an OFDMA system Fourth Generation: LTE and LTE Advanced With the growth of the internet and a growing need for wireless connectivity, ITU started the process of a new generation of mobile system standards in 2004. Initially a list of require- ments were approved for these new technologies. These included transmission rates and delay requirements as shown in Table 10.6 [15]. Furthermore, the new standards were designed from ground up to be a packet-switched, all-IP end-to-end system: from a wireless mobile device all the way through the core network to the internet. All transmissions were to use IP to pack- etise data and to transport the packets over the air interface as well as the core network. For example, voice communication was to be designed using voice over IP (VoIP) technology. The main emerging technology with this characteristic became known as Long Term Evolution (LTE) and LTE Advanced. The first set of standards was released in 2008 and the first opera- tional system rolled out in 2010. LTE is defined in Release 8 of the 36 series of the 3GPP UMTS standard [14, 16]. As noted above, the first release of the LTE standard was published in 2008. This standard is c