Phonons, the quanta of lattice vibrations, can exhibit unconventional transport behavior at microscopic scales such as nanostructured regions or interfaces, which cannot be explained by conventional thermal diffusion or particle pictures. This research topic aims to develop novel techniques for analyzing and measuring such phonon transport, with a particular focus on these non-conventional transport regimes. Furthermore, it seeks to advance a fundamental understanding of thermal transport and to establish next-generation thermal control strategies, for example, by developing methods that directly probe the spectral characteristics of phonon transport.