What is the Slice Concept in 5G Networks?

A network slice is a virtual logical network, which runs on common underlying physical infrastructure, and whose capabilities are optimised for a particular use case. Examples might include slices serving a utility company, a VN operator or a factory remote control system, or a slice that is optimized for the delivery of streaming video. Different network slices are isolated from one another, notably in respect of data transport (so that congestion in one slice does not affect any of the others) and security (so that an attack on one slice does not affect any of the others). An individual UE attaches to one or more network slices, depending on the resources that it requires.

As shown in the diagram, the 5G core and RANs both use the concept of Network Slicing. In the 5G Core Network, each slice is built from a set of VNFs with particular capabilities. Some VNFs can be used across multiple slices, while others are tailored to a specific slice. In the RAN, Network Slicing fits in well with the concept of a shared air interface resource, in which the different slices have different requirements for aspects such as admission control, state management and scheduling.

In many ways, the use of a mobile communication network to address multiple use cases is nothing new. However, NFV, SDN and Network Slicing have the potential to bring important benefits to the network operator. NFV and SDN provide a resource to network operators which is abstract and flexible, and  which is reconfigurable in a multitude of ways.