When defines where: how rural digital divide, customers' mobility and usage patterns have shaped mobile infrastructures

Extending and upgrading communication networks in rural areas is particularly challenging, due to the difficulties to recover the substantial investments it requires. Scholar and policymakers have identified mobile infrastructures as the most viable solution for these regions, owing to their flexibility and lower deployment costs. Techno-economic assessments supporting these recommendations typically rely on bottom-up demand models, with population as the primary input variable. In contrast to this traditional approach, our study shifts the focus to other variables that are highly relevant for mobile service providers: the number of fixed wireless access (FWA) subscriptions, customers' mobility patterns, and the spatiotemporal dynamics of communication services usage. We analyzed voice and broadband traffic data from all sites operated by a Spanish mobile service provider across different time frames, alongside data on FWA subscriptions per site and the number of mobile visitors per municipality. We began with a descriptive analysis of available data, segmented by municipality size, which revealed the unique characteristics of communication services usage in rural areas. These insights informed the development of both linear and non-linear demand models aimed at identifying the most influential variables driving communications demand at the municipal level. The results underscore the crucial role of non-resident users and FWA services in shaping demand—and, by extension, in guiding infrastructure investment decisions.