  Previous long-term monitorings of the gamma-ray-loud X-ray binary LS I
+61{\deg}303 have revealed the presence of a long-term modulation of ~4.5
years. After nine years of simultaneous monitoring of LS I +61{\deg}303 by the
Owens Valley Radio Observatory and the Fermi-LAT, two cycles of the long-term
period are now available. Here we perform timing-analysis on the radio and the
gamma-ray light curves. We confirm the presence of previously detected
periodicities at both radio and GeV gamma-ray wavelengths. Moreover, we
discover an offset of the long-term modulation between radio and gamma-ray data
which could imply different locations of the radio (15 GHz) and GeV emission
along the precessing jet.

High Energy Astrophysical Phenomena