Building a dense HetNet today, for a 5G tomorrow

The Future Network spoke to Sue Monahan, CEO of the Small Cell Forum, about the Asian small cell market following the Forum’s densification Summit at Reliance Jio’s offices in Mumbai. We discuss operator requirements and stakeholder engagement as we try to illustrate the current status of cellular networks in the APAC region and how they will evolve to 5G by 2020. Sue will be joining a panel at The Future Network Asia Meetup in Singapore (12-13 December).

The Future Network: Could you give us a high level overview of where the Asian market currently is in terms of operator sentiment towards network densification and the pressures they are currently facing?

Many operators will not deploy 5G at scale until 2020 or later. For some the priority is to add capacity and coverage to their LTE networks, but they also want to be able to include 5G at the right time for their business. This means building foundations for 5G even in the 4G network, and densification is an important aspect of this because it supports targeted capacity in a scalable way. This is particularly urgent in parts of APAC where there are extreme drivers for greater capacity – and this needs to be deployed in an affordable way, with a path to 5G. That means operators must rely on common frameworks, interfaces and processes, to improve the economics and ensure a path to 5G.

The Future Network: Why do you believe small cells are the technology of choice in network evolution? And what is unique about the Asian market specifically?

We see small cells as critical to the APAC mobile model, and Asian operators are currently leading the world in network densification because of the demands of their subscribers. This region has the highest growth rate in mobile data usage and that shows no signs of slowing down in the early 2020s. Operators need to expand their networks in four ways to meet this demand, and all of them require small cells:

1. More capacity: in order to boost network capacity they need to build denser layers of small cells

2. More coverage: in order to increase coverage, they need to deploy more cells, and these cells need to be more easily deployed

3. More spectrum: higher frequency spectrum is becoming available and these frequencies mainly support small cells

4. Shared spectrum: most of this is in mid-bands which are best for small cells

These factors are true in 4G but will be even more true in 5G which will move to hyperdensity in certain scenarios (urban centres, business campuses, venues, transport hubs etc).

Because of the factors outlined above, APAC operators are already leading the way in network densification, and small cells are central to advanced trials and deployments in Japan, South Korea, India and Singapore

The Small Cell Forum recently conducted a survey of about 75 mobile operators around the world and it found that in 2020, globally, one-third of small cells deployed in that year will be in hyperdense environments such as stadiums etc. But in APAC, the figure is far higher at 42%. (In our survey, hyperdense was taken to be above 150 small cells per square kilometer).

The Future Network: We’re heard about the need for network densification for many years, why do you believe that now is the time for it to finally happen?

Until recently, small cells were mainly deployed tactically to fill coverage and capacity gaps. Now there is an increasingly urgent need for larger numbers to be deployed, to densify large areas of the mobile network. This is particularly true in APAC.

There are four main areas of the MNO business where densification is urgent for some operators:

- Enterprise connectivity as businesses go mobile-first - enterprises need mobile connectivity for business-critical communications, IoT will accelerate such demand

- Densification in targeted high usage locations such as transport hubs etcetera - mobile data usage drives densification to scale

- Reaching remote areas and unconnected users - there are still many users who are underserved and must be connected. Small cells are at the heart of all these, but moving early brings the risk of technology dead ends

- Introducing 5G cells on a targeted basis when they are required - 5G is on the horizon, so today’s investments must be future-proofed with a common roadmap

In all cases, 4G networks must have a migration path to 5G. There are several deployment trends that are gaining urgency, and need more coverage and capacity before 5G arrives. Large-scale densification is becoming real especially in APAC as 4G rapidly advances but the big difference between 4G and 5G will be the scale/density. This is needed for hyperdense capacity and also for ubiquitous coverage e.g. for IoT, critical communications, and remote access. This can start with 4G but without a new architecture, networks will fail due to the cost of supporting rising demands, power consumption demands, and a lack of resource flexibility. 5G will be needed to drive down costs and power consumption and support new services e.g. ultra-low latency., and many early 5G trials are already focusing on these challenges in dense or challenging environments.

Small cell deployments have seen strong progress in the past one to two years with outdoor small cell deployments rising by 38% in 2016 (ABI), global revenues rising 8.4%  to $2.2bn in 2016 (IHS), and non-residential small cell deployments increasing 36% to 4.8m in 2016 (Rethink). But in dense environments in APAC, like urban centres, operators say they will need to increase cells by 800% by 2022, so faster progress is needed.

The Future Network: Can you please explain how you see the industry making the necessary progress? What needs to happen to make this possible? And how / where do you see small cells being deployed in the near future?

Deploying at this scale is uneconomic unless the cells are standardized, interoperable and can be easily upgraded or added for 5G. This is why a standards-based 4G-to-5G platform is essential. It is needed right now. According to the survey I mentioned earlier, 79% of MNOs aim to build a dense HetNet in at least one market by 2020, and of those, 30% already have plans to migrate their HetNet to 5G in 2019 to 2023. The market need to get from today’s situation – the start of densification, about 18m small cells in use – to the 5G requirement, about 40m small cells by 2022. This will require:

 - Flexible ownership models to reduce cost e.g. a neutral host

- Engagement with vertical markets – some industries and cities may run their own small cell networks

- Scalable repeatable deployment processes to reduce cost and complexity

- Migration to future standards with full interoperability

- Virtualization to support larger numbers of cells and greater flexibility

The Small Cell Forum’s path to 5G addresses all these key issues. Our aim is to drive the use of small cell technology which has open and interoperable standards, which engages enterprise verticals and establishes new ownership models to enable scalable, repeatable deployment and align the industry through a sequence of investments.

We have seen that large scale densification requires common standards and processes, but this does not mean that all the networks will be the same – small cells will be deployed in a huge variety of locations and use cases e.g. cities, rural areas, malls, stadiums, oil rigs. An advantage of the small cell is its versatility  -  small cells can be deployed anywhere and that means there are many form factors – standalone, clustered, virtualized, higher power (urban), ultra-low power (IoT) etc

The Small Cell Forum is working to help drive and define radio standards and interfaces for multivendor interoperability (e.g. Functional API (FAPI) - a multi-vendor platform interface, and nFAPI - a set of interfaces for supporting a virtualised MAC/PHY split) which will be pivotal in ensuring future interoperability for virtual small cell networks, enabling multi vendor C-RAN economics today as well as a smooth evolution path to 5G. We are also working on standardising common architectures e.g. HetNet framework and self-optimising networks (SON).

These common standards and frameworks are essential in encouraging innovation but avoiding fragmentation, driving economies of scale for chips and devices, lowering costs and reducing time to market for vendors and operators. Furthermore, high innovation within this common framework is needed to support many form factors and services, enabling accelerated availability for new and established service providers, and lowering barriers to innovation for vendors and operators.

The Future Network: And how do you plan to address the key industry deployment trends?

We have established five working groups to drive a 4G-to-5G common framework, these focus on: technology and 5G, interoperability, operations, business principals and marketing. These working groups are based on the requirements of our members and the operator community to define the technology needed for densification and drive ecosystem support; to enable scalable, repeatable deployment processes for density and massive connectivity; to understand and address specific needs of enterprise verticals; to establish new commercial models for ownership and operations; to ensure open and interoperable standards driving towards a healthy unfragmented ecosystem; and to drive industry agreement on the prioritized sequence of investments needed to take today’s networks into the 5G era. This involves a huge amount of work and no one organization can address all the issues of densification. The Small Cell Forum has always worked successfully with many partners and is intensifying this in the run-up to 5G. We have close alliances with a wide range of organizations including joint work on technology specifications and publications.

The Future Network: And finally, how to do you see the future of cellular networks evolving?

Over the next 10 years, SCF has the following vision, which builds on the priorities and goals outlined above. We aim to facilitate a fully virtualized, agile infrastructure that is capable of supporting multiple radio technologies, services and customer segments. We will work with businesses, consumers and regulators to ensure they are are aware of a range of small cells. We will encourage open and interoperable standards broadly embraced by the vendor community by engaging a range of connectivity resellers addressing targeted markets. 5G active sharing enables multi-operator neutral hosts and spectrum sharing, and zero touch self-configuration organises any deployment to operator acceptable quality. Ultimately we see a fully virtualized network that can be sliced and diced to offer a range of services  and optimized for different QoS requirements. At the Small Cell Forum, we are already starting work on the plan to make this vision a reality, and look forward to enabling operators to achieve a new level of densification in 5G, and deliver a whole new range of services.