The lack of spatial resolution and the inhomogeneity, in amount and geometrical coverage, of the observations of planetary radio emissions impose to derive indirectly or statistically such fundamental characteristics as their brightness temperature, emission mode, source location and morphology, or directivity (beaming). The current state of knowledge of these properties is here presented for the emissions of the five magnetized planets (the Earth, Jupiter, Saturn, Uranus and Neptune). Despite numerous phenomenological differences, the profound similarities that exist between the characteristics of the auroral emissions of these five planets suggest a common generation mechanism, able to be efficient in various planetary environments. The emerging comprehension of this mechanism recently allowed to probe successfully the magnetic field of Saturn through the variations of the high-frequency limit of its radio emission, and to propose a refined magnetic field model. We might soon be able to monitor the magneto-plasma in the auroral regions, which are key regions of the planetary magnetospheres. Finally, we will briefly summarize what is expected from future observations.