The neutral host model is well-established in certain parts of the wireless ecosystem, such as macro cell towers, but it is becoming attractive to a far wider range of stakeholders in the 5G era. This is because there is such a diversity of network requirements and business cases enabled by modern mobile broadband, and these can often be best enabled on shared infrastructure. However that diversity also threatens fragmentation of the market, so a global framework is urgently needed to allow a wide range of models to be developed on unified foundations. This is what SCF is proposing with its Hosted Open RAN framework, whose architectural requirements are set out in a landmark new report.
Mobile operators, and other network deployers, are looking to reduce the cost and risk of extending mobile broadband coverage into areas where it has been very limited to date, such as deep inside enterprise buildings or into every corner of a campus. This capacity and coverage would enable many new services, to benefit the user organizations and drive revenue to service providers. But the cost economics of a national macro network are very different from those of individual city, enterprise or industrial roll-outs.
This is driving operators to share more network assets, to co-invest with partners, and to outsource some elements completely to a third party, in order to reduce their total cost of ownership, replace capex spikes with predictable opex fees, and share the risk. For the user organizations, the footprint of the network is reduced if there is just one set of infrastructure, plus interference can be avoided, and energy consumption minimized.
However, this is not a one-size-fits-all model. Each deployment will have its own requirements in terms of density, coverage, performance and use cases, and each MNO has a unique network strategy.
One scenario may be best served by an established neutral host architecture such as DAS (distributed antenna system), others may be more effectively supported by emerging shared virtualized RAN platforms. However, using a mixture of sharing models can compromise the neutral host’s business case by creating fragmentation and complexity, and that can be exacerbated by the development of regionally specific approaches.
The key to supporting very varied performance and use case requirements is to allow many neutral host models to be developed, but to ensure that, to avoid fragmentation, these can relate to a common framework. That will bring confidence to deployers, scale to neutral hosts and vendors, and provide a broad platform for developers.
SCF is proposing a global framework called Hosted Open RAN to fulfil this need. This would provide a flexible and modular approach to hosting.
The architecture requirements for Hosted Open RAN are set out in a landmark SCF report. With contributions from 12 companies with different neutral host models in commercial use, the report is the first part of a series that will examine the technical and commercial aspects of emerging small cell neutral host models.
The report examines existing and emerging models, and the impact of developments such as shared spectrum – with a focus on the USA’s CBRS scheme – and open RAN architectures. These are likely to accelerate small cell build-out, especially in enterprises, by reducing the cost of spectrum and equipment, and lowering barriers to new deployers and suppliers. A proliferation of enterprise demand and potential providers will make shared infrastructure models increasingly vital to avoid fragmentation and ensure there is a robust profit model for all stakeholders.
The report analyses the requirements that will be fed into a proposed global framework for Hosted Open RAN networks. SCF believes Hosted Open RAN will become a dominant model for neutral host small cells in the coming years, combining the economics benefits of openness with those of shared infrastructure.
The framework aims to encompass many different approaches to neutral hosting, while providing a common architecture to allow common equipment and use cases to be adopted in all models – which range from site sharing to DAS to active small-cell-as-a-service.
Current specifications of relevance to neutral hosting will be supported and SCF has done particular work to support and align with JOTS NHIB (Joint Operator Technical Specifications for Neutral Host In-Building), a ground-breaking document supported by all four UK mobile operators – EE, Telefónica O2, Vodafone and 3 UK. This is an example of an approach that could be globally imitated, looking to address the cost and deployment challenges of delivering top quality 4G and 5G connectivity to enterprises, while ensuring a strong business case for operators.
Such frameworks, which are driven by operators with strong experience of sharing assets in other areas, help to reduce the perceived risks that MNOs often associate with sharing and neutral host, notably the ability to control every aspect of their network design and performance. They do this by enabling flexibility, so that an MNO’s particular requirements can be supported to a high degree, and by clearly setting out the cost, quality and time-to-market benefits. The deeper the sharing, the more these benefits are increased for the MNO, and the more quickly and reliably mobile broadband can start to make a significant impact on enterprises and citizens everywhere.