Solar Orbiter: Physical aspects towards a better knowledge of the solar corona

We consider the scientific aims and features of the Radio Plasma Waves (RPW) Analyzer on board the future mission Solar Orbiter. We emphasise on the solar radio observations in particular at hectometric, decametric and metric wavelengths. Two main parts are reviewed and re-examined: the classic observed spectral features and the main constraints due to the observational conditions on the ground and in space. We show that the RPW experiment is an excellent challenge and a good opportunity towards a better comprehension of the solar corona physics. Three main aspects are discussed: the micro-scale phenomenon, the propagation modes of the radio waves, and the localization of the radiation source regions.