Telegraph hill

For a list of places of named telegraph hills, see Telegraph Hill.

A telegraph hill is a hill or other natural elevation, chosen as part of an optical telegraph system because of the relatively great distance between it and at least one other point, which it may observe or be observed from. In the 18th and 19th centuries, such points were in some cases in permanent use for commerce and public administration, and in others, identified in advance of need or as need arose, especially for command and control in military operations.

Telecommunications

History	Beacon Broadcasting Cable TV Communications satellite Computer network Drums Electrical telegraph Fax Heliographs Hydraulic telegraph Internet Mass media Mobile phone Optical telecommunication Optical telegraphy Photophone Prepaid mobile phone Radio Radiotelephone Satellite communications Semaphore Smartphone Smoke signals Telecommunications history Telautograph Telegraphy Teleprinter (teletype) Telephone The Telephone Cases Television Timeline of communication technology Undersea telegraph line Videoconferencing Videophone Videotelephony

Pioneers	Edwin Howard Armstrong John Logie Baird Paul Baran Alexander Graham Bell Tim Berners-Lee Jagadish Chandra Bose Vint Cerf Claude Chappe Donald Davies Lee de Forest Philo Farnsworth Reginald Fessenden Elisha Gray Innocenzo Manzetti Guglielmo Marconi Antonio Meucci Alexander Stepanovich Popov Johann Philipp Reis Nikola Tesla Camille Tissot Alfred Vail Charles Wheatstone Vladimir K. Zworykin

Transmission media	Electromagnetic radiation Electrical cable Free-space optical communication Molecular communication Optical fiber

Network topology and switching	Links Nodes Terminal node Network switching (circuit packet) Telephone exchange

Multiplexing	Space-division Frequency-division Time-division Polarization-division Orbital angular-momentum Code-division

Networks	ARPANET BITNET Cellular network Computer CYCLADES Ethernet FidoNet Internet ISDN LAN Mobile NGN NPL network Public Switched Telephone Radio Telecommunications equipment Television Telex WAN Wireless World Wide Web

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