Single-sideband modulationIn radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of modulation used to transmit information, such as an audio signal, by radio waves. A refinement of amplitude modulation, it uses transmitter power and bandwidth more efficiently. Amplitude modulation produces an output signal the bandwidth of which is twice the maximum frequency of the original baseband signal.
BBC World ServiceThe BBC World Service is an international broadcaster owned and operated by the BBC. It is the world's largest external broadcaster in terms of reception area, language selection and audience reach. It broadcasts radio news, speech and discussions in more than 40 languages to many parts of the world on analogue and digital shortwave platforms, internet streaming, podcasting, satellite, DAB, FM and MW relays. In 2015, the World Service reached an average of 210 million people a week (via TV, radio and online).