Les écris permettent de laisser une trace, c'est l'objectif des cartes QSL, les transmissions radio, sont éphémères comme le vent...
ITU is the United Nations specialized agency for information and communication technologies – ICTs. "We allocate global radio spectrum and satellite orbits, develop the technical standards that ensure networks and technologies seamlessly interconnect, and strive to improve access to ICTs to underserved communities worldwide. ITU is committed to connecting all the world's people – wherever they live and whatever their means. Through our work, we protect and support everyone's fundamental right to communicate." source:http://www.itu.int