We present the result of multi-wavelength observations of the microquasar GRS 1915+105 in a plateau state with a luminosity of \sim 7.5 \times 10 ^ { 38 } erg s ^ { -1 } ( \sim 40 % L _ { \mathrm { Edd } } ) , conducted simultaneously with the INTEGRAL and RXTE satellites , the ESO Based on observations collected at the European Southern Observatory , Chile ( ESO N°071.D-0073 ) . /NTT , the Ryle Telescope , the NRAO The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities , Inc . 
VLA and VLBA , in 2003 April 2–3 .
For the first time were observed concurrently in GRS 1915+105 all of the following properties : a strong steady optically thick radio emission corresponding to a powerful compact jet resolved with the VLBA , bright near-IR emission , a strong QPO at 2.5 Hz in the X-rays and a power law dominated spectrum without any cutoff in the 3-400 keV range .