The path towards resource elasticity for 5G network architecture

Abstract

Vertical markets and industries are addressing a large diversity of heterogeneous services, use cases, and applications in 5G. It is currently common understanding that for networks to be able able to satisfy those needs, a flexible, adaptable, and programmable architecture based on network slicing is required. Moreover, a softwarization and cloudification of the communications networks is already happening, where network functions (NFs) are transformed from monolithic pieces of equipment to programs running over a shared pool of computational and communication resources. However, this novel architecture paradigm requires new solutions to exploit its inherent flexibility. In this paper, we introduce the concept of resource elasticity as a key means to make an efficient use of the computational resources in 5G systems. Besides establishing a definition as well as a set of requirements and key performance indicators (KPIs), we propose mechanisms for the exploitation of elasticity in three different dimensions, namely computational elasticity in the design and scaling of NFs, orchestration-driven elasticity by flexible placement of NFs, and slice-aware elasticity via cross-slice resource provisioning mechanisms. Finally, we provide a succinct analysis of the architectural components that need to be enhanced to incorporate elasticity principles.

Cloud Network Slicing: A systematic mapping study from scientific publications

“…In the literature, Orchestration is treated as a hot topic in CNS context [38,39], but the numbers show that only 7.77% (Figure 8) of the papers are focused on this theme. In Figure 9, we detail the results of orchestration and show that a small majority of papers focus on solutions related to the use of Artificial Intelligence (4,19%).…”

“…Elasticity is a feature that can dynamically reduce or add resources to meet tenants need [41]. In the CNS context, elasticity is a key feature and still an open challenge, due to the need to maintain end-to-end elastic resources across multiple administrative domains [38]. The CNS architecture must take into account not only the initial requirements, but also the system load, in order to trigger the elasticity process by expanding or reducing the resources available to meet SLA.…”

A Flexible Network Architecture for 5G Systems

“…In the 5G systems, where each slice is composed of multiple virtual NFs (VNFs), the elastic allocation available resources (either radio resources or computational resources) to different network slices based on their demands, requirements, and Service Level Agreements (SLAs) are essential. The architecture of 5G networks should provide the required elements and flexibility to implement elastic slice-aware resource elasticity while preserving the isolation of each network slice [18].…”

Service Shifting: A Paradigm for Service Resilience in 5G

“…In resource shortage conditions, the operator is unable to meet all target KPIs for all services. The traditional approach is to re-orchestrate [10] the affected services, which include (i) moving VNFs from unavailable servers to operating ones, and (ii) scaling down the resources they are assigned. This unavoidably results in KPI targets being violated, which, in turn, may jeopardize the usefulness of the service itself, e.g., lagging video for the see-through service discussed in Sec.…”