The ever-changing technologies and business models in our evolution-oriented world require existing networks to be equipped with low latency, high density and high throughput.
With the 5G transition, mobile network services have been classified into three categories by the International Telecommunication Union (ITU): 1) Enhanced Mobile Broadband (eMBB), 2) Ultra-reliable and Low-latency Communications (uRLLC), and 3) Massive Machine Type Communications (mMTC).
eMBB, uRLLC and mMTC explained
The first category, eMBB, focuses on mobile solutions that have high bandwidth requirements, such as streaming HD videos, Virtual Reality (VR) and Augmented Reality (AR). The second category, uRLLC, aims to meet the expectations of our highly demanding industry and focuses on latency-sensitive services, such as self-driving cars and remote management. Finally, mMTC, focuses on services that include high requirements for connection density, such as Smart Cities and IoT.
The evolution towards 5G networks: E2E Network Slicing
The 5G network will be designed for service-driven solutions that will be flexible and efficient enough to meet future mobile service requirements. With Software-Defined Networking (SDN) as an underlay and Network Functions Virtualization (NFV) supporting the underlying physical infrastructure, 5G will "cloudify" radio access and packet core elements. By moving and connecting your mobile infrastructure to the cloud, you can diversify 5G services and enable on-demand deployment, automated capacity planning and E2E Network Slicing of 5G network functions.
The key to the evolution of 5G networks is E2E Network Slicing, which is mandatory for supporting diversified 5G services. The infrastructure of future 5G networks is based on SDN/NFV technology and consists of a three-layer data centre architecture. In order for the different RAN (5G, LTE and Wi-Fi) functions to be managed in a flexible way in the three-layer data centre, there is a need for a strong computing capability, real time performance, specific dedicated hardware and sufficient storage respectively.
Lower maintenance and installation costs for operators with network slicing
Taking a closer look at the three-layer data centre, the bottom layer is defined as the central office data centre and is closest in proximity to the access network. Secondly, the middle layer is viewed as a local data centre, followed by the upper layer, also known as the regional data centre. The latter connects all layers together through transport networks, such as MPLS. The 5G network will generate a set of network topologies and network slices for each of the corresponding services using NFV in the data centre infrastructure. Network slicing will make sure that the exact resources in the joint network infrastructure are used for the service at hand. This results in lower maintenance and installation costs for the operators network. The network slices are separated as individual frameworks, which are heavily customisable and to be operated independently.
The Mobile Cloud Engine (MCE) and eMBB, uRLLC and mMTC
As shown in the above illustration, eMBB slicing requires high bandwidth to deploy caching in the Mobile Cloud Engine (MCE) of the local data centre, which provides high-speed services in close proximity to the users at a lower operating cost. uRLLC slicing has strict latency requirements when supporting self-driving cars and remote management. The RAN-Real-Time and RAN-Non-Real-Time functions are placed in the most beneficial location for the user. For RAN-RT this means close to the access network, while RAN-NRT is placed further down the data centre.
Communication services that are used in self-driving entities are handled by the Mobile Cloud Engine in the central office data centre, delivering very low latency. The control-plane functions lie further from the user in the local and regional data centres.
The applications of the mMTC slicing consume small amounts of network data, thus allowing the Mobile Cloud Engine to be deployed in the local data centre. Additional functions and applications can be installed in the regional data centre, which releases central office resources and reduces operating expenses.
The different functions used in 5G all have other demand, such as throughput, latency and the amount of connected devices. Network slicing optimises the use of existing hardware, resulting in lower OPEX and CAPEX.