5G introduces two key technologies that significantly advance active mobile infrastructure sharing opportunities. Firstly, network slicing enables the creation of distinct virtual networks on the same physical infrastructure. These slices offer performance guarantees and ensure that clients receive contracted Service Level Agreements (SLAs), instilling confidence and predictability for both operators and customers. Notably, network slicing requires a standalone (SA) 5G core. Secondly, Open RAN aims to disaggregate the radio access network into modular blocks that interoperate via standard interfaces, fostering vendor diversity. While various architectures exist for these blocks, the primary focus lies on the interface between the radio unit (RU) and the distributed baseband unit (DU).
This evolving landscape is prompting various parties to explore new active infrastructure sharing arrangements. In our new Insight Note, we outline several critical factors essential for evaluating and implementing such sharing models effectively.
Market Segmentation
It’s essential to first define the market and deployment scenario, as there are diverse forms to active infrastructure sharing, and the success of each hinges on the specific context of the market and deployment scenario. Important market segments to consider include:
- Market Considerations: Approval from national regulators is imperative for certain sharing arrangements, as they significantly impact cost structures and competitive positioning. Additionally, in some markets, mobile operators prefer an independent approach in selective or all types of deployments, rendering active sharing arrangements impractical. Understanding the regulatory and competitive landscape is crucial.
- Deployment type: Mobile infrastructure is deployed in both outdoor and indoor environments, each requiring distinct sharing mechanisms and arrangements.
- Site characteristics: Mobile infrastructure comprises macrocells (e.g., large towers and building rooftops) and small cells, where radio units are positioned a few meters above ground level.
- Type of area: Distinctions exist between urban and rural areas. Operators often lean towards infrastructure sharing in rural regions, where low subscriber density necessitates low infrastructure costs to reach financial breakeven.
- Type of sharing: Defining what to share is critically important and requires careful definition since it ultimately has consequences on the profitability.
Critical Factors to Successful Sharing
The critical factors to active mobile infrastructure sharing include assessment and harmonization of technical, operational, market, and financial factors:
Alignment of frequency spectrum assets. This aspect is pivotal, particularly when the subject of sharing is a radio unit compliant with ORAN standards and specifications. Questions surrounding the type and quantity of frequency bands, as well as their positioning in the frequency spectrum, must be addressed. The allocation of frequency spectrum and bands significantly influences the cost of radios and directly impacts the business case. Additionally, power allocation is another crucial consideration. Radios are typically subject to specific power limits, which must be divided among the various operators, necessitating careful trade-offs.
Alignment of operator technology roadmap and network architecture. Operators must synchronize their technology roadmap and network architecture, encompassing both the radio access network and the core network.
Initially, operators must harmonize their migration between technologies, such as transitioning from 4G to 5G and beyond. Considerations also arise regarding the deployment of a 5G standalone core versus the prevalent non-standalone architecture utilizing a 4G EPC to manage the 5G RAN. Notably, network slicing is only feasible with a 5G standalone core.
For instance, sharing a 5G base station in non-standalone mode necessitates utilizing the X2 interface between the 4G eNB anchor cell and the 5G gNB, requiring the use of the same vendor for both 4G and 5G networks. Additionally, careful consideration is warranted regarding the delivery of voice services in a shared network, such as VoLTE and VoNR implementation. Overall, network sharing in non-standalone mode is comparatively complex, emphasizing the importance of aligning operator roadmaps for network architecture and applications/features, such as standalone migration and voice service delivery.
Furthermore, coordination among service providers and their equipment vendors is imperative to ensure interoperability across all interfaces throughout the network’s lifecycle. Different frequency bands necessitate various architectures for supporting features like massive MIMO and beamforming, contingent upon both the radio unit and the baseband units.
Lastly, some sharing schemes mandate user devices to support specific features available in newer versions of standards. The impact of user devices is another important aspect when planning network sharing schemes.
Considering the myriad issues related to architecture and roadmap, establishing a common understanding of network architecture and supported feature roadmap is indispensable for the success of new active sharing models.
Maturity of interoperable interfaces. The success of new active sharing models hinges on standard-based interoperable interfaces within the radio access network, as defined by the 3GPP and the ORAN Alliance. It is imperative that operators align on the interfaces governing their agreement and the maturity of these interfaces. Additionally, mechanisms must be established to evolve over time to incorporate new features, emphasizing the critical importance of testing and verification processes.
Market assessment. This becomes crucial when a third party seeks to provide shared active infrastructure as a service. In such instances, the sharing context must encompass all competitive forces and dynamics among network operators, in addition to the market factors discussed earlier.
Operational assessment. Numerous network sharing agreements encountered challenges during the operational phase, often stemming from divergent priorities among operators across various dimensions. As a remedy, many agreements led to operators establishing joint ventures to oversee their shared active infrastructure. However, some of the new sharing models introduce an independent third party, necessitating a clear delineation of responsibilities for the shared infrastructure matrix.
Business model and financial assessment. Determining whether a third party should take on the role of operating and maintaining shared infrastructure is a matter tied to operational efficiency. Such a third party would assume specific liabilities as the owner-operator of the shared infrastructure. Therefore, establishing a compensation scheme and business model is crucial to ensure profitability.
Concluding Thoughts
It is worth noting a few use cases that, while not classified as active network sharing, yield similar outcomes. Private Virtual Network Operator (PVNO) serve as an example. In an PVNO setup, an enterprise (or virtual service provider) manages its core network, and mobile devices roam on a service provider network beyond the enterprise’s coverage area. Comparable approaches have been utilized to extend coverage to remote areas, often in partnership with local organizations responsible for deploying the radio access network.