Long-term flux monitoring of astrophysical sources enables detailed analysis of the timing characteristics of their emission. This can be a powerful tool to investigate the physical processes at work in these systems. The TeV-emitting binary star LS I +61°303 has been observed in radio monitoring programs since 1977. It has also been the target for monitoring at higher energies and is included in the search for neutrinos. Periodic signals in the radio emission from this source have been observed to be present and remain stable over decades. Modulation patterns are systematically related across the electromagnetic spectrum. I will discuss these findings in a scenario of periodic accretion onto a compact object and different emission regions within a precessing jet.