today. Even today most communications receivers produced for use in shortwave communication stations have BFOs. Radiotelegraphy industry The International Radiotelegraph Union was unofficially established at the first International Radiotelegraph Convention in 1906, and was merged into the International Telecommunication Union in 1932. When the United States entered World War I, private radiotelegraphy stations were prohibited, which put an end to several pioneers' work in this field. By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy by ships for both commercial purposes and passenger messages. The transmission of sound (radiotelephony) began to displace radiotelegraphy by the 1920s for many applications, making possible radio broadcasting. Wireless telegraphy continued to be used for private person-to-person business, governmental, and military communication, such as telegrams and diplomatic communications, and evolved into radioteletype networks. The ultimate implementation of wireless telegraphy was telex, using radio signals, which was developed in the 1930s and was for many years the only reliable form of communication between many distant countries. The most advanced standard, CCITT R.44, automated both routing and encoding of messages by short wave transmissions. Today, due to more modern text transmission methods, Morse code radiotelegraphy for commercial use has become obsolete. On shipboard, the computer and satellite-linked GMDSS system have largely replaced Morse as a means of communication. Regulation of radiotelegraphy Continuous wave (CW) radiotelegraphy is regulated by the International Telecommunication Union (ITU) as emission type A1A. The US Federal Communications Commission issues a lifetime commercial Radiotelegraph Operator License. This requires passing a simple written test on regulations, a more complex written exam on technology, and demonstrating Morse reception at 20 words per minute plain language and 16 wpm code groups. (Credit is given for amateur extra class licenses earned under the old 20 wpm requirement.) Gallery See also AT&T Corporation originally American Telephone and Telegraph Company Electrical telegraph Imperial Wireless Chain References and notes General American Institute of Electrical Engineers. (1908). "Wireless Telephony – By R. A. Fessenden (Illustrated.)", Transactions of the American Institute of Electrical Engineers. New York: American Institute of Electrical Engineers. Citations Further reading Listed by date [latest to earliest] Sarkar, T. K., & Baker, D. C. (2006). History of wireless. Hoboken, NJ: Wiley-Interscience. Hugh G. J. Aitken, Syntony and Spark: The Origins of Radio, . 1976. Elliot N. Sivowitch, A Technological Survey of Broadcasting’s Pre-History, Journal of Broadcasting, 15:1–20 (Winter 1970–71). Colby,