The mobile telecommunications industry has a dynamic competitive environment due to widespread and sustained technological change (Curwen and Whalley, 2004; Han and Sohn, 2016). We experience generational upgrades on at least a decadal basis, requiring Mobile Network Operators (MNOs) and other market actors to have an understanding of future digital evolution. Even market leaders with significant advantages in the telecommunications industry can fall behind if they are unable to keep abreast of new developments and actively adapt existing market strategies for new conditions (Asimakopoulos and Whalley, 2017). Indeed, the digital ecosystem is experiencing significant disruption from new digital platforms and services (Ruutu et al., 2017; Wang et al., 2016), with substantial ramifications for MNOs as revenues have been either static or declining (Chen and Cheng, 2010), and these conditions exist alongside the increasing operational costs of serving ever increasing mobile data traffic. Hence, in wireless telecoms, MNOs must be aware of both opportunities and threats arising from technological change, particularly when moving from one generation to the next (du Preez and Pistorius, 2003; Salmenkaita and Salo, 2004). Telecommunications are essential for modern economic activities, as well as for a fully functioning society. These technologies can enable economic growth through new content, services and applications (Hong, 2017; Krafft, 2010), while also enabling productivity improvements throughout the economy by lowering costs. The ability of Information Communication Technologies (ICT) to interchange data via telecommunications networks is essential for the economic development of the digital economy (Cheng et al., 2005; Kim, 2006; Wymbs, 2004), and the range of industrial sectors it comprises. New cross-sectoral advances have also emerged, such as the Internet of Things (IoT) and Smart Cities (Almobaideen et al., 2017; Bresciani et al., 2017; Hong et al., 2016; Yang et al., 2013), which rely on the availability of digital connectivity for smartphones, sensors and other communications devices. Hence the signal quality of mobile telecommunications infrastructure is an ever more important factor, requiring operators to focus on both network reliability and capacity expansion techniques to meet consumer and industrial requirements (Shieh et al., 2014). This is challenging however, given the weak revenue growth currently experienced, leaving only a modest appetite for infrastructure investment. Scenario planning is a foresight tool that can be applied to understand how changes in the external environment may affect current or potential market strategies (Ramirez et al., 2015). On the one hand, this approach can be used to foster learning and the adaptive skills of an organisation (Favato and Vecchiato, 2016), while on the other, it supports high-level strategic decision-making (O’Brien and Meadows, 2013; Parker et al., 2015). Quantified approaches allow one to measure the impact of external drivers using systems modelling. Importantly, the choice of how much infrastructure is required, when, and where, is seen to be a problem of decision-making under uncertainty (Otto et al., 2016). The aim of this paper is to quantify the uncertainty associated with the future demand for mobile telecommunications infrastructure, to test how different strategies perform over the long term. We focus specifically on capacity expansion via 5G mobile telecommunications infrastructure.