Efficient deployment of small cells

Recently at a Cambridge Wireless combined Small Cell and Smart and Intelligent Cities SIG meeting, the attendees heard about the impressive densification of networks in Japan, Korea and China. These markets have far fewer constraints on deployment; the US and EU markets seem unlikely to achieve such liberalisation of small cell deployment approach. A resource efficient approach to harnessing small cell is needed.

Whatever the barriers, it’s certainly true that outdoor small cells will help in dense urban areas, to deal mainly with increasing capacity challenges arising from demand for new and faster services. Although some small cells may also have coverage applications in rural areas. Whilst it is likely that in some dense LTE-A macro network deployments it will be possible to avoid small cells, new ownership models and difficulties with enhancing all macro sites will mean small cell is part of the toolkit.

Either way, there’s going to be a need for economically viable small cell deployments and it’s hard to disagree with a key phrase in the report: “The most pressing challenges relate to the time and cost to deploy a small cell.” However, one obvious caveat is the likelihood that operators will try to put off that time and cost for as long as they can by sweating existing cellular assets where possible. This means higher order MIMO, usage of all available spectrum and adding as much sectors as feasible to their macro cites in high demand areas.

That isn’t a cause for complacency of course. We should, as the report suggests, be worrying about capacity demand. To operate a highly spectral efficient network, capacity should be delivered as close to the area of demand (high user density) as possible, and small cells can address such hotspots. However, I’m not sure, as the paper says, that it is “5G itself” that is driving scale. Whether it’s LTE, LTE+ or 5G, people will continue to consume more capacity to support their smartphone use and operators are going to have to deliver it. Independent of the name or type of technology, additional infrastructure has to be deployed and cells will be closer to users (shorter cell ranges & lower inter-site distances) to offer more capacity and address increasing demand.

As small cells become part of this process, the paper is inarguably right that approvals and processes are far too slow and should therefore be standardised or broadly applicable guidelines should be introduced. We at Real Wireless would also suggest a stronger emphasis on promoting the socio-economic benefit of small cell sites for councils and local authorities rather than only focusing on fees and revenues from street infrastructure rent. The right infrastructure will also bring the benefits of pervasive broadband (reducing the digital divide) an is an IoT enabler, which may support councils’ challenges in e.g. the transportation, health and social services domain, where technology has substantial cost savings potential.

But even if all this is done, that still leaves you with the unavoidable problems of power and fibre deployment challenges and its costs, which are responsible for a large part of the small cell deployment expenditure (small cells themselves are – relatively speaking – cheaper than ever). Standardisation of installation types, locations, methodology, output power limits and, yes, aesthetics would certainly help the small cell rollout process – but the infrastructure rent, power supply and backhaul needs to be addressed too.

There is a precedent for such activity – and it’s one we have been involved in. In 2017, Real Wireless worked as part of Cornerstone Telecommunications Infrastructure Ltd’s (CTIL’s) bid team to provide technical advice on small cells, including deployment, coverage modelling, capacity requirements, backhaul and the long-term use of small cells in the City of London.

This was a complex project in which our expert advice played a significant role – one we offer infrastructure owners, towercos, MNOs or neutral hosts to help them obtain access to the right infrastructure and sites at the right cost and to put them in the right places.

And we’re continually innovating; we tools that produce granular demand forecasts for urban centres based on multiple big data sources. These future demand heatmaps will make capacity planning and cell placement easier by helping operators to see and understand population and demand movement at different times of the day and over longer periods.

We think this sort of work will play a growing part in network densification planning. Given the costs of small cell deployment, blanket coverage does not seem the right approach for capacity driven densification. We agree with the small cell paper: An enabling environment is critical for the success of small cell rollout. But we would add that it’s also very much about informed and intelligent smart cell placement – the smarter the better.