5G promises mobile operators a world of unprecedented speed and differentiated quality of service, with the potential to unleash a wide array of new services and business models. Yet many find themselves held back by a lack of agility and scalability in their current mobile networks. The rigid architecture of existing mobile networks is typically composed of network domains designed as sets of tightly-coupled functions that need to be deployed and executed together as monolithic entities. As a result, they lack the capability to support 5G’s requirements for differentiated, highly efficient scaling of individual application components or for dynamic scheduling of components that are needed to maximize performance and minimize resource consumption. In addition, the existing networks cannot be optimized to address the individual needs of different services.
In a highly competitive market, one of the main goals of mobile operators’ 5G strategies is to innovate, create, test and deliver services more rapidly, while also saving costs and still delivering a high quality of service (QoS). To achieve this, most operators are basing their 5G network strategy on building new networks that leverage software-defined networking (SDN) and network functions virtualization (NFV) – the technologies driving a shift from legacy, purpose-built hardware infrastructure to service-driven, programable networks.
NFV in particular will play a crucial role in mobile operators’ journeys to 5G. Network functions that rely on microservices-based, cloud-native architecture frameworks are virtualized and hosted in a cloudified network infrastructure. Furthermore, loosely coupled microservices-based network functions can be dynamically and independently scaled and consumed, radically improving system agility.
To implement these new technologies and network architectures, mobile operators will need to adopt new automated network operations methodologies for operating the agile and programmable 5G network. This automation is essential both for monetizing the growing 5G opportunity, and for achieving maximum operational efficiencies.
The network evolution from evolved packet core (EPC) to 5G core (5GC) and virtualized radio access network RAN (RAN) plays a vital role in creating a powerful programmable network platform that will enable mobile operators to extract more value from their networks. As network elements and functions across the RAN, edge and core are virtualized and sliced out as one integrated end-to-end service, mobile operators will be able to create virtual networks that meet the needs of specific services, enterprise customers or entire industries.
The 5GC network is founded on service-based architecture (SBA), where control plane network functions (NFs) expose their services to other NFs using service-based interfaces (SBIs). The 5GC will be more agile, easily scalable, flexible, and open than existing core network, enabling operators to decouple network functions from hardware, implement component-based functions and adopt a stateless design as well as lightweight, open interfaces. The 5GC NFs are organized as smaller, manageable and loosely-coupled stateless services and stateful backing services, allowing each service to be individually deployed, scaled, and upgraded. This architecture means that mobile operators can open up their networks, utilize best-of-breed NF software from many different vendors, benefit from flexible deployment of NFs, and create an agile and scalable platform that supports the introduction of software-driven services to accelerate innovation and time to market.
5GC NFs expose their services to other NFs via well-defined 3GPP SBI HTTP/2 RESTful APIs that support diverse service types. Using scalable cloud-native architecture provides the ability to spin up the exact number of specific NFs to gain the most efficient utilization of network resources when accommodating high-peak rates. This architecture also allows distributed deployment of 5GC NFs, where some functions are placed closer to the edge of the network to reduce latency. Using virtualized, scalable, core network functions enables service providers to allocate dedicated network functions to specific network slice services or to allow a number of network slices, which can dynamically scale when needed, to share the same network function.