Multi-access Edge Computing (MEC) and its important role in 5G implementationsAugust 31, 2018
Physical-Layer Network CodingSeptember 3, 2018
Multi-access Edge Computing (MEC) relies on the combination of various cutting-edge technologies  such as cloud computing and virtualization, a concept deployed near the end user (UE) proximity, instead of a central location. Furthermore, utilizing network function virtualization (NFV), software defined networks (SDN) and network slicing (NS) attributes, crucial requirements such as flexibility and multitenancy support are enabled. In detail:
- Cloud computing is a fusion of technologies which aims to provide computing power, storage, data access and several other services on demand. User requests a service from the “cloud” without caring where the service has come from but needing to be provided with the service he or she paid for under certain, mutually agreed, rules. A cloud platform typically consists of a number of physical machines that comprise a single logical entity. Using a hypervisor, virtual machines (VMs) that host different tasks are being deployed in an isolated manner, ensuring the physical resource allocation in each VM. VMs are an abstraction of the physical stack (i.e. BIOS, memory, CPU, storage) and requires an Operating System (OS) to be executed inside it. On the other hand, a more lightweight form of virtualization, the container, allows multiple instances to run under the same OS, enabling a fast deployment and execution of the required tasks. VMs can support heavier applications which require a higher degree of security, whilst containers can facilitate lighter applications in environments that require mobility.
- NFV enables the separation of traditional network functions from proprietary hardware, enabling a softwarized network architecture via virtual network functions (VNFs). VNFs are able to scale up or down the resources allocated to the data and the control plane, reflecting the current network needs. VNFs may reside across multiple VMs over a cloud infrastructure, thus, by bringing the cloud to the edge, VNFs may be executed in UE proximity. NFV defines 3 domains, the VNFs that are software implementations of network functions, the NFV infrastructure (NFVI) that offers the software and hardware components where VNFs are being executed and the NFV management and orchestration that provides the organization and management of the physical and virtual resources of the NFVI.
- SDN is a technology that enables network programmability, logically centralized intelligence and control, by decoupling the control from the data plane and abstraction of the network where services and applications are abstracted from the underlying technologies and hardware that provide the physical connectivity. MEC can leverage the SDN paradigm for providing network connectivity and service management across an heterogeneous MEC platform. Furthermore, SDN transforms the traditional proprietary networking equipment into a simple data plane that can be controlled at the ingress and egress network points.
- NS constitutes a key concept for enabling an agile network platform to support diverse use cases, over the same underlying infrastructure. It practically “slices” the network into multiple instances, each one of them used for a service or a group of similar services, having their own dedicated end-to-end (E2E) resources (e.g., RAN, computing, control plane) in order to form an E2E slice. NS introduces a network hypervisor, similar to cloud computing’s hypervisor concept, enabling the allocation of virtual of physical network resources to the tenants of the slice. The combination of NVF and SDN technologies is crucial in order for NS to ensure the service customization that is required by the diverse services and applications, supporting a coordination for the VNF allocation across the edge network.
 P. Mach and Z. Becvar, “Mobile Edge Computing: A Survey on Architecture and Computation Offloading,” in IEEE Communications Surveys & Tutorials, vol. 19, no. 3, pp. 1628-1656, 2017.