Which will be more important for 4G/5G coverage expansion: Neutral Host, or RAN-Sharing?

There are increasing demands for better mobile coverage in areas that are technically complex, or which struggle economically with traditional MNO deployment models. 5G's use of new and higher frequencies will exacerbate the problems.

Even with a shift to pure private networks for some enterprises, there will still be a need for the public mobile networks to have better coverage for their subscribers in places such as:

• In-building locations, including both private offices and public venues
• Metro in-fill sites, needed to densify cellular networks in busy cities - but where cell-siting and connectivity challenges can be immense
• Rural areas, where mobile users are sparse and sometime lower-ARPU
• Along road and rail routes, especially where new connected vehicle uses are expected
• Anywhere with few people, but more IoT devices
• Business sites where multi-operator connectivity is needed (eg construction sites)

There are various approaches emerging to solve these issues:

• More flexible / cheaper RAN deployment options for individual MNOs to extend their own networks
• RAN sharing (including national roaming)
• Neutral host networks (NHNs)
• Various hybrid schemes with government involvement

The middle pair -  NHNs and RAN-sharing - are perhaps the two most interesting, as they fit with a lot of other developments around local and dynamic spectrum licensingto , OpenRAN and NFV, and a move to multi-MNO collaboration.

Yet which will win out, and in what contexts?
 
RAN sharing involves 2+ existing mobile operators combining network assets to save costs, perhaps through a joint venture. There are various types with differing levels of sophistication, from sharing physical towers & power, through to shared backhaul, core networks, baseband units & even spectrum. (MORAN, MOCN, etc) 

Neutral hosts are 3rd parties which build a RAN (and may have spectrum of their own) and which then sign up national MNOs or new niche/private cellular providers as tenants. Again, there are various technical and commercial models emerging. 

In theory, NHNs are more flexible, and push the capex to the new host operator. 

But what are the practicalities? Many questions arise: 

• Coverage locations & backhaul availability. What works best in rural, metro, indoor or industrial locations?
• Does an NHN need a core network? Standalone? Also VoLTE?
• Does this all apply to 4G, 5G, or both? 
• Where do OpenRAN or modern DAS & small-cells fit best? If these overlap with NFV and netwrk-slicing, can each "tenant" MNO bring its own software, if they want?
• How does security work for all parties? This is a huge and diverse minefield, relating to everything from RF interference and license conditions, to the physical integrity of network elements, down to lawful intercept and data-collection requirements.
• What are the contractual & regulatory hurdles? 
• What about other stakeholders like venue owners, property companies, towerco's and local authorities? 
• Who puts all of this together? What's the value chain, and which systems integrators and other partners will be involved?
• Will a neutral-host also offer neutral-edge computing capabilities?

There are no easy answers to all of this - the answer will generally be "it depends", both on use-case and national market.
 

I'll cover all these topics & more in next week's 2nd Neutral Host workshop in London on November 21st. Full details and registration page here: [link]