Source-linked AI summary
From Network Sharing to Multi-tenancy: The 5G Network Slice Broker
Konstantinos Samdanis, Xavier Costa-Perez, Vincenzo Sciancalepore
TL;DR
Rising traffic and infrastructure costs motivate the evolution from conventional network sharing toward 5G multi-tenancy. The paper reviews 3GPP standardization and introduces a signaling-based 5G Network Slice Broker that supports on-demand, SLA-based resource allocation for multiple tenant types. It places the broker within the infrastructure provider’s management architecture to mediate tenant requests and physical network resources.
Problem
Operators need cost-efficient ways to accommodate increasing traffic and support new business participants beyond traditional single-infrastructure ownership.
Method
The paper reviews 3GPP network-sharing evolution and proposes a 5G Network Slice Broker built on the network-sharing management architecture and service-exposure mechanisms.
Results
The proposed broker enables on-demand signaling-based resource allocation and admission control for MVNOs, OTT providers, and vertical industries using SLA and network-monitoring information.
Takeaways & Limitations
The 5G Network Slice Broker mediates multiple tenants’ SLA requests and physical RAN resources within a 3GPP-compliant management architecture.
Abstract
from arXiv · showhide
The ever-increasing traffic demand is pushing network operators to find new cost-efficient solutions towards the deployment of future 5G mobile networks. The network sharing paradigm was explored in the past and partially deployed. Nowadays, advanced mobile network multi-tenancy approaches are increasingly gaining momentum paving the way towards further decreasing Capital Expenditures and Operational Expenditures (CAPEX/OPEX) costs, while enabling new business opportunities. This paper provides an overview of the 3GPP standard evolution from network sharing principles, mechanisms and architectures to future on-demand multi-tenant systems. In particular, it introduces the concept of the 5G Network Slice Broker in 5G systems, which enables mobile virtual network operators, over-the-top providers and industry vertical market players to request and lease resources from infrastructure providers dynamically via signaling means. Finally, it reviews the latest standardization efforts considering remaining open issues for enabling advanced network slicing solutions taking into account the allocation of virtualized network functions based on ETSI NFV, the introduction of shared network functions and flexible service chaining.
1. Introduction
Rising traffic and deployment costs motivate network sharing and multi-tenancy as ways to reduce infrastructure burdens and support new participants. The paper traces 3GPP evolution and proposes a signaling-based 5G Network Slice Broker for on-demand resource allocation.
- Motivation: Traffic growth from multimedia, cloud applications, and vertical services challenges operators to expand capacity without substantially increasing infrastructure and operational costs.
- Motivation: 50% of radio access sites generate less than 10% of revenue, while sharing can recover up to 20% of operational costs and at least halve passive RAN infrastructure costs.
- Motivation: Network sharing can accelerate roll-outs, reduce site-acquisition difficulties in urban areas, and shorten investment payback periods in rural areas.
- Paper scope: The paper reviews 3GPP business requirements, architectures, and management frameworks before introducing enablers for flexible on-demand multi-tenant networks.
- Paper scope: Its proposed 5G Network Slice Broker uses signaling, admission control, and resource assignment to serve requests from MVNOs, OTT providers, and vertical players.
2. Network Sharing Scenarios and Business Requirements
Network sharing supports different commercial objectives across markets and participants, but operators must balance efficiency gains against competitive risks. 3GPP identified multiple scenarios spanning shared RANs, coverage collaboration, and expanded multi-tenant participation.
- Business objectives: Infrastructure providers seek additional revenue and better CAPEX/OPEX returns, while MVNOs use sharing to extend services where owning infrastructure would not meet business targets.
- Market context: Mature markets generally emphasize return on investment and capacity enhancement, whereas developing markets usually prioritize coverage expansion.
- Market context: Operators assess sharing according to its purpose and the risk that competitors could gain advantages, with sensitivity varying by market and service differentiator.
- 3GPP scenarios: One 3GPP scenario lets multiple core networks share a common RAN while retaining separate operator core connectivity and spectrum arrangements.
3. Early Network Sharing Standardization and Architectures
3GPP progressed from simple passive sharing and roaming in Rel.99 to active RAN sharing architectures that pool access resources while preserving different degrees of core-network separation and flexibility.
- Early standardization: 3GPP Rel.99 introduced UMTS network sharing through passive sharing and network roaming, after early GSM and UMTS designs centered on single-MNO networks.
- Passive sharing: Passive sharing covers site locations and physical support infrastructure, while mast sharing can additionally co-locate sites and share antenna frames without sharing radio equipment.
- Active sharing: Active RAN sharing pools spectrum alongside access equipment and can extend sharing to base stations, antennas, and mobile backhaul.
- Active sharing: MOCN keeps separate operator EPCs and connects shared eNBs to each operator core, supporting customization such as per-operator load balancing.
- Active sharing: GWCN additionally shares the MME, increasing cost savings compared with MOCN but reducing flexibility for inter-RAT mobility and circuit-switched voice fallback.
- Active sharing: MOCN generally requires more investment but offers greater flexibility, while UE behavior remains identical and resource sharing is transparent in both architectures.
4. Incorporating Virtual Operators & Verticals in 3GPP Networks
3GPP management and service-exposure mechanisms let infrastructure providers share resources with virtual operators and third parties. These mechanisms support monitoring, secure access, charging, QoS, SLA control, and programmable service capabilities.
- Network management: The 3GPP SA5 management architecture supports long-term contractual sharing between an infrastructure provider and participant MVNOs through the Type 5 interface.
- Network management: The Master Operator can forward performance-monitoring information to participant network managers, while Itf-N and Itf-B support monitoring, reporting, configuration, and control.
- Service exposure: SCEF securely exposes selected 3GPP service capabilities to OTT providers and vertical industries through network APIs within the operator trust domain.
- Service exposure: Exposed capabilities include third-party authentication and authorization, charging, QoS provision, SLA monitoring, user-context information, and admission control.
- Service exposure: SCEF APIs enable applications to obtain customized service capabilities and support network programmability for using available resources.
5. 5G Network Slice Broker - Architecture
The 5G Network Slice Broker extends 3GPP network-sharing management to support dynamic, signaling-based resource allocation for multiple tenants. It maps SLA-driven requests to network resources while coordinating slice configuration, monitoring, admission control, and cell selection.
- Broker concept: The on-demand capacity broker allocates a specified portion of network capacity to MVNOs, OTT providers, or vertical players for a particular time period via signaling.
- Broker concept: The 5G Network Slice Broker establishes network slices as isolated network capacity customized to specific service requirements.
- Management architecture: Co-located with the MO-NM, the broker accesses load, mobility, failure, SLA, and infrastructure-capability information while receiving MVNO resource requests.
- Management architecture: The broker mediates between tenant SLA requests and physical resources, with the SCEF providing access for OTT providers and vertical industries through network managers.
- Interface enhancements: Slice signaling must carry resource amounts, timing, resource and QoS types, data volumes, and service information such as mobility and offloading policies.
- Interface enhancements: The requested cell set may be supplied by the MVNO or determined by the InP, then communicated through Itf-N for configuration through Itf-B.
6. The Network Slicing Road towards Full Multi-tenancy
Full 5G multi-tenancy extends network slicing beyond shared capacity by incorporating virtualization and software-based capabilities. Slices can receive tailored virtual functions and edge resources for services with distinct performance priorities.
- Evolution toward multi-tenancy: Full multi-tenancy relies on virtualization and software-based capabilities that extend network slicing to particular communication services.
- Network Function Virtualization: 3GPP adopted ETSI NFV MANO to assess impacts on network management and identify reusable or extensible requirements, interfaces, and procedures.
- Network Function Virtualization: Release 14 introduced architecture requirements for virtualized network management alongside specifications for configuration, fault, performance, and lifecycle management.
- Service-specific slices: Different slices can share infrastructure for mobile broadband, automotive, and massive IoT services, with latency, reliability, or scalability as critical requirements.
- Service-specific slices: Network functions can be instantiated at the edge cloud as necessary to accommodate strict latency and scalability goals.
7. Conclusion
The paper reviews 3GPP’s evolution from network sharing toward on-demand multi-tenancy and introduces the 5G Network Slice Broker as an infrastructure-provider function. It also surveys standardization work on virtualization and flexible provisioning of network functions and services.
- The paper reviews network-sharing architectures, management extensions, service exposure, and standardization efforts supporting multi-tenancy.
- The 5G Network Slice Broker resides inside the infrastructure provider and supports on-demand multi-tenant networks through required interfaces and functional enhancements.
- The paper surveys 3GPP Release 14 and external standardization efforts addressing virtualized network functions and flexible network-slice services.