  The controversy and argument on the usefulness of the physical layer (PHY)
academic research for wireless communications are long-standing since the
cellular communication paradigm gets to its maturity. In particular,
researchers suspect that the performance improvement in cellular communications
is primarily attributable to the increases in telecommunication infrastructure
and radio spectrum instead of the PHY academic research, whereas concrete
evidence is lacking. To respond to this controversy from an objective
perspective, we employ econometric approaches to quantify the contributions of
the PHY academic research and other performance determinants. Through empirical
analysis and the quantitative evidence obtained, albeit preliminary, we shed
light on the following issues: 1) what determines the cross-national
differences in cellular network performance; 2) to what extent the PHY academic
research and other factors affect cellular network performance; 3) what
suggestions we can obtain from the data analysis for the stakeholders of the
PHY research. To the best of our knowledge, this article is the first
`empirical telecommunication research,' and the first effort to involve
econometric methodologies to evaluate the usefulness of the PHY academic
research.
