A study of Pc-5 magnetic pulsations using some data from the ACE, Wind, Polar Cluster, Geotail and Goes-10 spacecrafts and ground-based magnetic field measurements from the Intermagnet archive was carried out. Solar wind in the Earth's orbit is a quasi-stationary formation with tangential discontinuous, fast and slow shock waves. We accentuate our study on geomagnetic pulsations associated with sudden storm commencements (SSC) and sudden impulses (SI). The disturbances of magnetopause surface produce the fast MHD wave front which penetrates into the magnetosphere. Pulsations associated with fast waves were detected on spacecrafts and on the Earth's surface with the same frequency. Pulsations excitation can be considered as one of energy transport mechanisms from solar wind to the ionosphere. Frequencies of detected pulsations depend on geomagnetic latitude and approximately correspond to the toroidal alfvenic mode. Pulsations with different frequencies were observed simultaneously on different magnetic latitudes. The existence of spectral maxima after wideband fast MHD waves propagation testify the magnetosphere property to select particular spectral peaks and to produce Pc3-5 pulsations with expressed periodicities. The Earth's magnetosphere is assumed to be the resonance system for hydromagnetic waves excited due to the shocks outside the magnetosphere.