Historical Review (3/3) Early 20th century: 1920:AM radio broadcast ■ 1933:FM radio broadcast 1929:Television system in US ■ Most communication systems are analog. ■ Engineering designs are ad-hoc,tailored for each specific application Meixia Tao SJTU 17Meixia Tao @ SJTU Historical Review (3/3) q Early 20th century: n 1920: AM radio broadcast n 1933: FM radio broadcast n 1929: Television system in US n Most communication systems are analog. n Engineering designs are ad-hoc, tailored for each specific application 17