Amateur radio advanced digital communication network in brief

Amateur radio, often called ham radio, is both a hobby and a service in which participants, called "hams," use various types of radio communications equipment to communicate with other radio amateurs for public services, recreation and self-training. Amateur radio operators enjoy personal (and often worldwide) wireless communications with each other and are able to support their communities with emergency and disaster communications if necessary, while increasing their personal knowledge of electronics and radio theory. An estimated three million people throughout the world are regularly involved with amateur radio. Amateur radio operators use various modes of transmission to communicate. Voice transmissions are most common, with some, such as frequency modulation (FM) offering high quality audio, and others, such as single sideband (SSB) offering more reliable communications, often over long distance, when signals are marginal and bandwidth is restricted, without sacrificing audio quality. Over the past century amateur radio operators have contributed to our understanding of radio communications, devised entirely new radio communication technologies, combined pre-existing technologies in innovative new ways, and developed operational procedures that have largely defined the way in which communication by radio is carried out. Amateur radio has played a fundamental role in the development of radio and telecommunications technology, and it continues to do so today.