Software-defined networking (SDN) and network function virtualisation (NFV) are two technologies that have become extremely essential for leveraging the full potential promised by 5G networks. These technologies play a crucial role in enabling both network softwarisation and virtualisation, which are the main drivers of innovation in the 5G era. The dual characteristics of softwarisation and virtualisation allow developers and operators to build both application-aware networks and network-aware applications to match their business demands. Further, SDN and NFV technologies help operators scale and configure their networks easily to allow a seamless interaction between different services operating in the core network.

A look at the role that SDN and NFV can play in the 5G world…

Role of SDN in 5G

In a nutshell, SDN technology comprises a smart network architecture designed to reduce hardware constraints. It allows operators to build intelligent, flexible and programmable 5G networks that are capable of orchestrating and controlling applications/services in a more fine-grained and network-wide manner. It also provides them the capability of responding rapidly to changing network conditions, business, market and end-user needs.

SDN does this by creating a virtualised control plane that can enforce intelligent management decisions among network functions, thereby bridging the gap between service provisioning and network management. With the adoption of SDN, network control becomes directly programmable, using standardised interfaces.

Moreover, SDN solutions can provide an overall framework to enable 5G networks to function across a normalised control plane. This helps manage network behaviour through application programming interfaces. SDN can also provide better data traffic management by determining optimal data flows in real time, minimising network bandwidth, boosting latency and allowing efficient performance monitoring of 5G networks.

Role of NFV in 5G

NFV is a technology that allows a 5G physical network to be divided into various virtual networks capable of supporting multiple radio access networks (RANs) across different customer segments and environments. The fundamental concept behind NFV is to separate the hardware layer from the software layer.

By leveraging NFV, operators can implement a string of network-connected devices without investing in expensive proprietary hardware. These network functions can be set up in a few weeks, unlike the proprietary hardware that takes months to install. In terms of 5G, NFV aids virtualisation of multiple layers. Particularly, NFV allows 5G network slicing that permits numerous virtual networks to function on top of just one physical infrastructure. Further, NFV allows service providers to dynamically create service chains in the network, depending upon the type of 5G service. This grants flexibility to service providers and enables them to scale up/ down services to address changing customer demands. It also reduces their capital and operational expenditure through lower-cost agile network infrastructure and decreases the deployment time of new network services to market.

Another major change required in 5G networks is in terms of radio specifications. Unlike 4G, 5G requires a dense network with towers installed in almost every street. If service providers end up deploying hardware-based RAN, the capex would shoot up. In this scenario, NFV can help operators in virtualising RAN and migrating select RAN functions to the cloud, thereby bringing down the cost of the network infrastructure.

Moreover, 5G networks are evolving as network equipment vendors continuously roll out software upgrades/patches for introducing new functionalities in the network. When the 5G core infrastructure is virtualised and supports cloud-native services, a network equipment vendor can just roll out a patch for a specific network function only. This simplifies the management of network services.

Enabling programmability of network

A key feature unique to 5G is network programmability. In the 5G era, a whole gamut of new communication demands would emerge from a wide array of devices, users and companies across different industries. To sufficiently manage these demands, 5G networks would have to be programmable, flexible, modular, software-driven and managed in a manner that supports a diverse and profitable range of services.

All individual domains of the network – mobile core, RAN and transport network – would require a high level of programmability and flexibility. SDN technology has a key role to play in this regard, as it can enable network programming.

A programmable 5G network provides service agility by shortening the time for service creation and adaptation, service diversity by sharing a single infrastructure among multiple services with a wide range of requirements, and resource efficiency by dynamically allocating the right amount of resources wherever needed.

Diversifying service offerings through network slicing

Another disruptive concept that is new to the 5G era is network slicing. Through network slicing, a single 5G physical network can be sliced into multiple isolated logical networks of varying sizes and structures, dedicated to different types of services. It allows operators to create different levels of services for different enterprise verticals, enabling them to customise their operations. According to a GSMA report, network slicing is an integral component for unlocking the enterprise opportunity, amounting to $300 billion by 2025 in the 5G era.

To leverage these benefits, operators would have to adopt NFV solutions, that provide the necessary infrastructure for orchestration and automation of network slices. Further, each of these network slices would have its own characteristics such as speed, latency and quality of service.

The way forward

Net, net, SDN and NFV technologies form the backbone for building programmable, flexible and customisable 5G networks. Further, the adoption of these solutions provides the ability to manage and provision network services from a centralised location, enabling faster and cost-efficient delivery of bandwidth on demand, with minimal disruptions. Moreover, the cloud architecture that SDN and NFV solutions use has features such as data analytics and automation, which are not available in legacy networks.

To leverage these opportunities, many global operators are scaling up their investments in SDN and NFV solutions. For instance, major telecom service providers (TSPs) in the US, Europe and a few countries in the Asia-Pacific region have started investing in SDN and NFV. Primarily, TSPs in the West are focusing less on SDN- and NFV-based cost savings and more on service innovation and revenue growth opportunities.

Recently, US-based telco AT&T, which has launched its 5G services in certain markets, announced how its investments in SDN and NFV have been playing an instrumental role in keeping pace with the rising internet traffic stemming from the changed working scenario during the Covid-19 crisis. According to the company, the demand for its virtual private network offering increased by about 700 per cent as people began working from home. However, building its network on software and open hardware specifications enabled AT&T to accommodate this demand without facing any problems.

Such examples make the case for deploying SDN and NFV solutions even stronger, especially for Indian telcos that are yet to adopt them on a large scale. According to industry experts, the adoption of SDN and NFV is slow in India as technology standards are still evolving.

Going forward, as India plans to make the giant leap towards rolling out 5G networks, operators need to recognise the crucial role that SDN and NFV can play in enabling multiple use cases in the 5G era. Telcos need to work with global co-location and interconnection providers offering carrier-grade infrastructure and a wide range of easy-to-deploy SDN and NFV solutions. This would enable them to realise the full potential of 5G services and build flexible, scalable and customisable networks for the future.