Dynamic Slice Scaling Mechanisms for 5G Multi-domain Environments

Network slicing is an essential 5G innovation whereby the network is partitioned into logical segments, so that Communication Service Providers (CSPs) can offer differentiated services for verticals and use cases. In many 5G use cases, network requirements vary over time and CSPs must dynamically adapt network slices to satisfy the contractual network slice QoS, cooperating and using each others’ resources, e.g. when resources of a single CSP are not sufficient or suitable to maintain all it’s current SLAs. While this need for dynamic cross-CSP cooperation is widely recognized, realization of this need is not yet possible due to gaps both in business processes and in technical capabilities.In this paper, we present a 5GZORRO approach to dynamic cross-CSP slice scaling. Our approach both enables CSPs to collaborate, providing security and trust with smart multi-party contracts, and facilitates thus achieved collaboration to enable resource sharing across multiple administrative domains, either during slice establishment or when already existing slice needs to expand or shrink. Our approach allows automating both business and technical processes involved in dynamic lifecycle management of cross-CSP network slices, following ETSI’s Zero-Touch Network and Service Management (ZSM) closed-loop architecture, and relying on resource-sharing Marketplace, Distributed Ledger (DL), and Operational Data Lake. We show how this approach is realized in truly Cloud Naive way, with Kubernetes as both business and technical cross-domain orchestrator. We then showcase applicability of the proposed solution for dynamic scaling of Content Delivery Network (CDN) service.

I. Introduction

5G telecommunication networks introduce drastically improved Key Performance Indicators (KPIs) in terms of bandwidth, latency, reliability, availability, and device density. While this opens up possibilities for numerous novel applications, the “one-size-fits-all” approach is highly inefficient due to the diverse QoS requirements of applications. The need to simultaneously and cost-effectively address different use cases has motivated the use of novel technological solutions such as SDN and NFV to virtualize the physical 5G network into multiple logical networks having different resource allocations and providing different QoS levels [1]. This approach is termed network slicing and offers isolation and differentiated QoS guarantees to network silces [2].