ty and user experience. The tactile Internet is a forward-looking usage scenario under the category of ultra-reliable low-latency communication (URLLC) services. A notable requirement for enabling the tactile Internet is to place the content and context-bearing virtualized infrastructure at the edge of the AN [mobile edge com- puting (MEC)]. This relocation provides a path for new business opportunities and col- laborative models across various service platforms. Improved access to the content, context, and mobility are vital elements to address the demands for reliability, availabil- ity, and low latency [62]. While much has been written and speculated about the next-generation radio standards that are going to form the basis of the forthcoming 5G systems, the core network is also an essential piece in achieving the goals set forth for these systems and in helping to ensure the competitiveness and relevance of network operations in the future. With the advent of heterogeneous ANs, that is, deployment of different radio access technologies with different 4 Chapter 1 coverage footprints, seamless connectivity, and service continuity can be provided in vari- ous mobility classes. The availability of different types of footprints for a given type of wireless access technology characterizes heterogeneous access, for example, a radio network access node such as a base station with large to small coverage area is referred to as macro-, pico-, and femtocell, respectively. A combination of these types of base stations offers the potential to optimize both coverage and capacity by appropriately distributing smaller-size base stations within a larger macro-base station coverage area. Since the radio access tech- nology is common across these different types of base stations, common methods for con- figuration and operation can be utilized, thereby enhancing integration and operational efficiencies. The diversity of coverage, harnessing of spectrum (e.g., licensed and unli- censed spectrum), and different transmission power