Network Slicing: Paving the way towards 5G technology

Network characteristics and requirements

Network Slicing promises to transform what was a ‘best effort’ network to one which offers far more reliability. The basic concept is the ability to build logical (virtual) networks, called “Network Slices”, on top of shared physical resources by providing them as a service to support diverse use cases with distinctive characteristics and requirements. There may be many slices on top of the same physical network, each dedicated to specific services or customers, fostering flexibility and the efficient use of resources, to allow for more business cases. Slicing can be threatening to the Network as software, hence the logical network slices are easy to manage and dynamically change (e.g. according to exceptional events).

Network Slicing: cutting the same net into several slices

One of the strengths that is underlined by 5G mobile networks is the ability to provide broadband and low latency connections, even when you have a large number of objects connected to the network. Each use case has its own requirements, and many of them can be orthogonal in terms of quality, allowing efficiency in infrastructure sharing scenarios.

For example, when considering an Autonomous Vehicle scenario, which requires low latency and high reliability for safety as a Virtual Reality use case, it requires a high throughput with relaxed reliability since losing a few pixels, frames, or lower resolution may be affordable. Those two quality parameters could be granted, at the same time, by the same physical infrastructure. On top of the same hardware a network slice can be built to support the Vehicle Network, with specific KPIs in terms of latency, and another network slice to provide large throughput for VR applications.

From an implementation perspective, Network Slicing will be possible thanks to the extensive use of the Software Defined Networking (SDN) paradigm, to control the many devices involved along with Network Functions Virtualization (NFV) to build logically dedicated functions for each of the slices.

As an example, Mobile network operators, can divide their network into smaller virtual subnetworks and connect them to each other. Since each partitioned virtual network provides independent network functions, the services and functions can be adapted to a customer needs. Slicing can be used to virtually partition the wireless access network, as well as the core components of the Evolved Packet Core (EPC) or the data centers. Characteristics of network slicing are flexibility, common infrastructure, isolation and a dedicated network.

Why is Network Slicing needed?

The need for network slicing arises when each application should "see" a network configured in the optimal way to manage its traffic. This is possible with slicing, even if the network that the application sees is a "slice", a virtual "slice" of the physical network. The advantage of network slicing is not only in showing an application its ideal network.

The various "slices" of the physical network are also isolated from each other and this, for example, guarantees both greater communication security and the possibility of modifying the operation of one slice without affecting that of the others. This means that an operator can drastically modify a service that it offers to its customers by only acting on one slice in a targeted manner. This would also allow conducting tests and research on dedicated slices, where each slice can mirror a production network, without affecting other slices that serve the live network with real services on top.

When is it used?

The need comes when the network provider wants to share a common hardware infrastructure in order to support diverse services, each with specific requirements. It allows infrastructure sharing in a flexible and more efficient way, since the virtual slice can be “tailored” for the specific service, without including all the features of the underlying network.

It can be said that slicing is used whenever there is a common infrastructure where on-demand customization is available, by assuring isolation, guaranteed performance, scalability, support for multi-vendor and multiple-operator scenarios.

Main actors and applications

Network Slicing will bring benefits to various players who will be able to take advantage of a shared hardware infrastructure that supports many logical and virtual networks, delivering different and independent services.

Those players can be the developer, the provider, or the users of those virtual services. Their are many market sectors interested in the impact of Network Slicing: Multimedia, Telco and Virtual Operators, Tourism, Energy, Health, Smart City, Public Safety, Manufacturing, Logistics, Agriculture, Automotive, Retail, Industry 4.0 and IoT in general.

Reply and Network Slicing

Reply has gained a lot of experience by working on several projects and developing many 5G use cases for most market areas.

As an example, in recent years, Reply incubated Zeetta Networks: an innovative startup in Bristol, working in the field of Software Defined Networking. Integrating and improving open source technologies, they developed NetOS: a network orchestrator able to govern complex multi-vendor and multi-platform networks in a simplified and abstracted way, even implementing Slicing features. Zeetta Networks is quite active in 5G experimentation and trials, with projects related to Smart Cities, IoT, private LTE and Slicing.

At Reply, we built portable network innovation labs which integrate a fully featured NetOS platform to demonstrate 5G scenarios and use-cases, the enterprise slicing concept and how to harmonise slicing inside a company with Telco 5G Network Slicing.

Slicing may also be added on platforms like Access 4.0, an open source-based edge cloud for access between end user and core network, where Reply is co-development partner of Deutsche Telekom AG, and which is suitable for access through broadband fibre (GPON) as well as other technologies as Radio Access Networks (RAN) and 5G.