History of mobile phones
A cellular telephone switching plan was described by Fluhr and Nussbaum in 1973, and a cellular telephone data signaling system was described in 1977 by Hachenburg et al.
Invention of the telephone
A later telephone design was publicly exhibited on May 4, 1877, at a lecture given by Professor Bell in the Boston Music Hall. According to a report quoted by John Munro in "Heroes of the Telegraph":
Going to the small telephone box with its slender wire attachments, Mr. Bell coolly asked, as though addressing someone in an adjoining room, "Mr. Watson, are you ready!" Mr. Watson, five miles away in Somerville, promptly answered in the affirmative, and soon was heard a voice singing "America". [...] Going to another instrument, connected by wire with Providence, forty-three miles distant, Mr. Bell listened a moment, and said, "Signor Brignolli, who is assisting at a concert in Providence Music Hall, will now sing for us." In a moment the cadence of the tenor's voice rose and fell, the sound being faint, sometimes lost, and then again audible. Later, a cornet solo played in Somerville was very distinctly heard. Still later, a three-part song came over the wire from Somerville, and Mr. Bell told his audience "I will switch off the song from one part of the room to another so that all can hear." At a subsequent lecture in Salem, Massachusetts, communication was established with Boston, eighteen miles distant, and Mr. Watson at the latter place sang "Auld Lang Syne", the National Anthem, and "Hail Columbia", while the audience at Salem joined in the chorus."