Role of NFV in 5G network

Service providers across the globe are busy building their 5G network foot print and Network Functions Virtualization (NFV) plays an integral part of the 5G infrastructure. While many telcos have been virtualizing their network infrastructure for the last 3+ years, 5G makes NFV, almost mandatory. While 4G's Evolved Packet Core (EPC) was an evolution from the 3G packet core networks, the 5GC (5G Core) has been designed from its inception to be “cloud native”. 5G Core inherits many of the technology solutions used in cloud computing. NFV plays a critical role in the success of 5G implementation.

What is the role of NFV in 5G networks?

1. Enables Virtualization of Cloud RAN - One of the major changes in 5G is the changes to the radio specification (5G New Radio Specification). Unlike 4G, 5G towers (aka small cells) have to be installed almost in every street - to achieve coverage and speed. If service providers end up deploying hardware based RAN (Radio Access Network), the CAPEX would go up. Virtualizing RAN and migrating select RAN functions (for ex., Base Band Unit function) to the Cloud would help service providers to bring down the cost of the network infrastructure. Service providers have to just deploy antennas on the streets and the heavy lifting of handling the data workloads will be done in the edge cloud. 
2. Provides Infrastructure for Network Slicing - Network Slicing allows the same physical network infrastructure to be partitioned and made available as multiple logical / virtual network slices. Each of the network slices would have their own performance (speed / latency) and quality of service characteristics. User-subscribed services (for ex., Enhanced Mobile Broadband) will get mapped to the network slices. NFV provides infrastructure for orchestration and automation of the life cycle management of network slices. 
3. Makes the 5G network elastic and scalable - Given the dynamic nature of the bandwidth demands and the diversity of the 5G use-cases, it is important for service providers to build an elastic network that scales-in / scales-out based on demand. For example, there will be a number of mobile connections originating from the residential areas, during late evenings and early mornings. However, during the day, there will be more mobile connections originating from industrial / work locations. A static network will result in low utilization of the network infrastructure.  5G infrastructure services are cloud-native, thereby making the network more dynamic. If there are unused 5G core instances in the cloud, they can be temporarily shutdown to save power and cooling costs in the data center. An elastic 5G network will also improve the user experience - as the network adapts to the user's demand. 
4. Enables 5G network to support a "Service-based" architecture - 4G networks are connection based, whereas 5G network architecture is "service-based". In a service based architecture, E2E services are provided by creating service chains that span across multiple network functions. For ex., a Live TV service may not just depend on video streaming servers running on the network edge, but may also have specific latency requirements from the network infrastructure. NFV allows service providers to dynamically create service chains in the network, depending upon the type of the 5G service. 
5. Improves the agility and simplifies network upgrades - Given the fact that 5G network is continuously evolving - network equipment vendors are continuously rolling out software upgrades / patches introducing newer functionalities in the network. When the 5G core infrastructure is virtualized and supports cloud-native services, a network equipment vendor can just roll out a patch for a specific network function (for example, Policy Charging Function (PCF)), as opposed to the complete Evolved Packet Core. This simplifies the management of the network services, for the service providers.