5G Network Slicing and Applications

Network Slicing - Paving the Way Towards 5G

- The Use Cases of Network Slicing

Network slicing is a method of creating multiple unique logical and virtualized networks on a common multi-domain infrastructure. Using software-defined networking (SDN), network functions virtualization (NFV), orchestration, analytics, and automation, mobile network operators (MNOs) can quickly create network slices that support specific applications, services, user sets, or networks. Network slicing can be deployed across multiple network domains such as access, core, and transport, and across multiple operators.

Network slicing and its myriad of use cases is one of the most important technologies in 5G. It will support new services with vastly different requirements—from connected vehicles to voice calls, which require different throughput, latency, and reliability.

The use cases identified for 5G and network slicing fall into three broad categories:

1. Extreme (or enhanced) Mobile Broadband (eMBB). These apps are very video-centric, consume a lot of bandwidth, and will generate the most traffic on mobile networks.
2. Massive Machine Type Communication (mMTC). This is commonly referred to today as the Internet of Things, but on a much larger scale, with billions of devices connected to the network. These devices will generate much less traffic than eMBB applications, but they will generate a lot more traffic.
3. Ultra Reliable Low Latency Communications (urLLC). These will allow for remote surgery or vehicle-to-X (v2x) communications and will require mobile network operators to have appropriate mobile edge computing capabilities.

With network slicing, each slice can have its own architecture, management, and security to support specific use cases. While functional components and resources can be shared across network slices, features such as data speed, capacity, connectivity, quality, latency, reliability, and service can be customized within each slice to meet specific service level agreements (SLAs).

Automation will be a key component of network slicing, as MNOs are expected to have to design and maintain hundreds or thousands of network slices. MNOs cannot manually manage so many slices at the rate customers demand. Instead, end-to-end automation must be used to dynamically perform zero-touch slice lifecycle management at scale and in real time as traffic loads, service requirements, and network resources change. However, once this capability is in place, it will open up many new revenue opportunities for MNOs.

With 5G, mobile network operators can now incorporate cloud-native applications into their networks, avoiding vendor lock-in and realizing lower development costs, improved modification and upgrade capabilities, and enhanced vertical or horizontal scalability. MNOs should strongly consider adopting cloud-native slicing applications to take advantage of this and ensure they can support evolving 5G standards.

- To Enable Different Deployments and Architectural Flavors for Various Business Models

5G networks will have to support diverse and stringent requirements of latency, throughput, capacity, and availability. With its unified design, 5G, an integrated connectivity fabric, offers an exciting promise of being able to Slice the Network to serve a wide range of applications with very distinct reliability and throughput requirements. 

A network slice is defined as a logical (virtual) network customized to serve a defined business purpose or customer, consisting of an end-to-end composition of all the varied network resources required to satisfy the specific performance and economic needs of that particular service class or customer application. With this Network Slicing concept, operators can enable different deployments and architectural flavors for various business models, use cases or service groups. They can run all network instances in parallel on a shared network infrastructure.

Some business models, for example, network slicing enables the network elements and functions to be easily configured and reused in each network slice to meet a specific requirement. One slice simply looks like self-contained network that includes the core network and the RAN. However, each of these slices can have its own network architecture, security, quality of service and network provisioning as a result of the network virtualisation software implementations. 5G effectively allows a network slice to be a low-security, low-bandwidth network for one application and a high-security, high-reliability one for another application. 

- 5G End-to-End Network Slicing

The new era of 5G connectivity will be characterized by its wide diversity of use cases and their varied requirements in terms of power, bandwidth, and speed. The greater elasticity brought about by network slicing will help to address the cost, efficiency, and flexibility requirements imposed by future. In addition, the benefits of slicing for specific verticals are quickly emerging. For example, ultra- reliable low latency communications (URLLC) is focused on providing support for critical infrastructure and applications such as connected transportation and real-time processes such as in manufacturing. IoT has numerous verticals and each of those verticals have varied network requirements. Slicing provides the ability to support these vertical use cases by creating a tailored virtual slice of the network from end to end. 

End-to-end Network slicing is a major characteristic of the 5G System. It is supported by every deployed PLMN (Public Land Mobile network) to the extent necessary to interoperate with other PLMNs, e.g. the IoT slice from operator A can interconnect directly with the IoT slice of operator B. Based on business scenario, the operator can decide how many network slices to deploy and what functions/features to share across multiple slices. 

The characteristics of each slice are defined in terms of QoS, bit rate, latency, etc. For a given slice, these characteristics are either predefined in the 3GPP Standard or are operator-defined. There are three types of predefined slices: type 1 is dedicated to the support of eMBB, type 2 is for URLLC and type 3 is for MIoT support. These predefinitions allow inter-PLMN operation with reduced coordination effort between operators. As for the operator-defined slices, they enable more differentiation among network slices.

- Network Softwarization and Virtualization

5G virtualization is crucial and inevitable. Without virtualization, 5G will be unable to meet its connectivity requirements. The network will not be able to adapt quickly enough to keep up with the rampant technological changes in ancillary domains. 

Network operators are facing great challenges in terms of cost and complexity in order to incorporate new communication technologies (e.g., 4G, 5G, fiber) and to keep up with increasing demands of new network services to address emerging use cases. Softwarizing the network operations using Software-Defined Networking (SDN) and Network Function Virtualization (NFV) paradigms can simplify control and management of networks and provide network services in a cost effective way. 

Softwarization using SDN) and NFV in 5G networks are expected to fill the void of programmable control and management of network resources.

- SDN, NFV and 5G Networks: Opportunities and Challenges

As 5G emerges, it will converge with other evolving technology and network architecture concepts, such as software-defined networking (SDN), network functions virtualization (NFV), cloud and edge computing and changes in base station design. SDN and (NFV are the key pillars of future networks, including 5G and Beyond that promise to support emerging applications such as enhanced mobile broadband, ultra low latency, massive sensing type applications while providing the resiliency in the network. 

Service providers and other verticals (e.g., Connected Cars, IOT, eHealth) can leverage SDN and NFV to provide flexible and cost-effective service without compromising the end user quality of service (QoS). While NFV and SDN open up the door for flexible networks and rapid service creation, these offer both security opportunities while also introducing additional challenges and complexities, in some cases. 

With the rapid proliferation of 4G and 5G networks, operators have now started the trial deployment of network function virtualization, especially with the introduction of various virtualized network elements in the access and core networks. These include elements such as virtualized Evolved Packet Core (vEPC), virtualized IP Multimedia Services (vIMS), Virtualized Residential Gateway, and Virtualized Next Generation Firewalls. 

Network slicing is a type of virtual networking architecture in the same family as SDN and NFV - two closely related network virtualization technologies that are moving modern networks toward software-based automation. SDN and NFV allow far better network flexibility through the partitioning of network architectures into virtual elements. In essence, network slicing allows the creation of multiple virtual networks atop a shared physical infrastructure. 

SDN and NFV are hot topics. NFV allows for virtualization of network resources, and SDN separates control plane functions from data plane functions to enable more centralized, flexible and programmable management of networks. SDN and NFV are used to customize the network offering, supported by automation, service provisioning and orchestration. But the uncoupling of hardware and software does not only facilitate greater network efficacy and efficiency. It inherently lends itself to a more democratic approach to wireless innovation, promising improved services, better network economics, and shorter times to market for new network vendors.

- 5G Virtualization, SDN, NFV, and Network Slicing

Network Virtualization (NV) releases the network from its anchor in hardware and runs a virtual network on top of the physical network. The result is a more dynamic system that can be controlled from a central plane, removing the need for humans to manually configure pieces of hardware.

5G network virtualization will permit the division of hardware resources into functions that can be controlled by software: network functions virtualization (NFV). In network management, NFV seeks to directly optimize network services. The associated network management approach, software-defined networking (SDN), establishes a centralized view of the network by detaching the control and forwarding planes. As a result of NFV, network resources can be configured and allocated to service the needs of specific customers or service categories, without needing physical adjustments or dedicated infrastructures. Such a restructuring will pave the way for much-vaunted 5G capacities like network slicing. This architecture introduces the possibility of multiple virtual networks on top of shared physical infrastructure.

Each network slice can be dedicated to specific functions, clients or use cases, delivering elevated service within each segment, and a higher-performing network overall. Network slicing will be the key ingredient in 5G’s ability to support and deliver value from the three ITU-specified generic services with vastly heterogeneous requirements: enhanced Mobile Broadband (eMBB), Ultra-reliable and Low-latency communications (URLLC), massive Machine Type Communications (mMTC). Within these three areas, we will see the emergence of high-speed mobile applications, driverless cars, and mIoT. But, importantly, these use cases will all have different network requirements such as speed, latency, stability, and security. Network slicing makes it possible to satisfy these needs in a dispersed, yet coordinated and tailored way