By 1924 it was apparent that amateurs would have to make way for other services. Today, the amateur service retains relatively narrow bands throughout the radio spectrum from 1.8 MHz through 250 GHz. These bands provide the whole range of radio wave propagation mechanisms and, through experimentation, amateurs have greatly contributed to the understanding of propagation. To date, over 40 satellites have been designed, constructed and operated by radio amateurs. Radio amateurs have made significant technical contributions to the field of radio propagation high frequency single sideband radio, HF data communication systems, packet radio protocols and communication satellite design.
Amateur radio continues to play an important role in disaster communication.
It has a unique ability to provide radiocommunication independent of the telephone network or other radio services particularly in the first few days before relief agencies are at the scene and have set up disaster telecommunication services. This includes training of young people in radiocommunication. Radio amateurs have the opportunity of planning, designing, building, operating and maintaining a complete radio station, which contributes to the telecommunication human resources development of a country. It is intended to concentrate in one volume all ITU texts concerning these services.