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Standards, Protocols, and Functions
LTE (Long-Term Evolution) of UMTS (Universal Mobile Telecommunications Service) is one of the latest steps in an advancing series of mobile telecommunication systems. The standards body behind the paperwork is the 3rd Generation Partnership Project (3GPP).
Along with the term LTE, the acronyms EPS (Evolved Packet System), EPC (Evolved Packet Core), and SAE (System Architecture Evolution) are often heard. Figure 1.1 shows how these terms are related to each other: EPS is the umbrella that covers both the LTE of the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and the SAE of the EPC network.
Figure 1.1 EPC and LTE under the umbrella of EPS.
LTE was and is standardized in parallel to other radio access network technologies like EDGE (Enhanced Data Rates for GSM evolution) and HSPA (High-Speed Packet Access). This means that LTE is not a simple replacement of existing technologies. Rather it is expected that different kinds of radio access will coexist in operator networks.
From this background it emerges that understanding LTE also requires understanding alternative and coexisting technologies. Indeed, one of the major challenges of LTE signaling analysis will concern the analysis of handover procedures. Especially, the options for possible inter-RAT (Radio Access Technology) handovers have multiplied compared to what was possible ...
