Many in-building wireless systems have been installed with the primary focus on ubiquitous coverage. Benoit Fleury, VP Product Line Management at iBwave, believes the time has come for capacity planning to take a more prominent role.
He explains why in-building design needs to take a comprehensive view of capacity provided across 3G, LTE and Wi-Fi technologies, termed HetNet Capacity Planning, and how that can be achieved today.
It’s the result that counts
Ultimately, business success for network operators is all about the end user experience. People don’t really care what wireless technology or generation is used to connect their smartphone device. They do care (and notice) if their Apps don’t work properly whenever and wherever they want.
With traffic forecast to grow at over 50% compound annually worldwide, it’s simply not enough to plan for good coverage and signal-to-noise ratio. Even today, many networks – both cellular and Wi-Fi - are designed without capacity constraints in mind. These need to take into account a better understanding of the density of users, the Apps in use and how these change over time. For example, a busy conference room or caféteria at lunchtime may result in poor service causing frustration to end users. .
In-building wireless design practices are maturing
However we are starting to see that view change with increasing focus on the end user experience and capacity limits. In high profile public venues such as airports and stadiums, operators are typically closely involved in network design and capacity is always taken into consideration. Very often, operators will have their own home-grown strategy and design rules for capacity planning, implemented in a simple spreadsheet model. It’s usually included as part of the design process, but more commonly treated as an afterthought.
As the industry scales up to rollout larger numbers of Enterprise Small Cells, this simple spreadsheet approach breaks down. Certain assumptions about traffic characteristics may not be true for small to medium sized buildings. We can expect to see more machine-to-machine devices, evolving user Apps and changing use cases. Tariff plans also radically change behaviour and traffic loads – consider the effects of T-Mobile’s Binge-On or Verizon’s Go90 offers.
A holistic approach incorporating 3G, LTE and unlicensed
What’s required is a holistic approach to capacity planning for 3G, LTE and Wi-Fi rather than dealing with each technology separately. At iBwave, we have talked with many operators, equipment vendors and system integrators worldwide to understand their needs.
Our goal was to find a way to address capacity modelling that included the scope of both technology and planning rules. In our discussions, we have discovered that each operator has its own “Rules of Engagement” based on their method of doing business and strategic focus. These rules or methodologies take into account what spectrum assets they own, the maturity of smartphones in their installed base and their appetite to make use of Wi-Fi. This leads to choices about which technology to serve data and voice through – some will retain 3G for voice, others promote VoLTE and a few prioritise Wi-Fi Calling in certain situations. Some champion LTE for all data services while others strive to offload as much to Wi-Fi as feasible.
Within each building, these voice and data services could be delivered through a mix of DAS, Small Cells and Wi-Fi with some equipment shared by operators.
iBwave has developed a comprehensive traffic modelling suite that builds on the early concepts used in the simpler spreadsheets. It focuses on the end user experience, taking into account the Apps and services (e.g. streaming video, uploading photos, voice calls etc.), the changing patterns throughout the day and the device capabilities (e.g. all smartphones don’t fully support all available frequency bands or VoLTE).
This supersedes the spreadsheet methods in common use today, and makes the capability available for use in all Enterprise installations. System Integrators can incorporate this as part of their standard RF design process. The feature is integrated into the iBwave Release 8 suite and is very intuitive to use, despite being comprehensive and fully featured.
Capacity-related heat maps allow the designer to easily visualise the end-user experience in different areas of the venue. The figure below illustrates an example of one of the outputs supported by the iBwave Design tool showing average data throughput per user in each zone of the venue. A pass-fail indicator is also provided, leading to a rapid assessment of whether or not the design criteria have been met.
Capacity planning isn’t just a one-off activity
With traffic demand continuing to increase at such high compound growth rates, it makes sense to increase capacity incrementally throughout the lifetime of an in-building wireless deployment. This avoids overspending on excess capacity at the outset while cost-efficiently keeping up with demand.
Sometimes enough capacity can be added simply by upgrading the size of the backhaul connection. More often a thorough performance analysis can reveal specific areas, times and use cases leading to specific recommendations for new and/or moved radio nodes.
Different operators have different strategies on how to handle capacity growth. Some have periodic strategic reviews, maybe every one or two years, to assess and plan upgrades. Others rely on a monitoring approach which triggers action when predefined limits are breached.
In-building wireless system design needs to include comprehensive capacity planning that addresses all forms of Wireless service – 3G, LTE and Wi-Fi. Planning purely for coverage alone is no longer enough.
With Enterprise Wireless deployments scaling to address many more buildings, a comprehensive, intuitive HetNet Capacity Modelling tool is essential to meet user experience cost effectively.
iBwave provides the HetNet Capacity Planning capabilities that the industry will require as it scales up to roll out larger volumes of Enterprise Wireless deployments.