Search results
Results from the WOW.Com Content Network
Wireless telegraphy or radiotelegraphy is the transmission of text messages by radio waves, analogous to electrical telegraphy using cables. [1] [2] Before about 1910, the term wireless telegraphy was also used for other experimental technologies for transmitting telegraph signals without wires.
A telegraph is a device for transmitting and receiving messages over long distances, i.e., for telegraphy. The word telegraph alone generally refers to an electrical telegraph. Wireless telegraphy is transmission of messages over radio with telegraphic codes.
Number 1 Electronic Switching System (Alcatel-Lucent) US 1FR: Flat rate service: US 2G: second-generation mobile telephone 2.5G: Enhanced 2G mobile telephone 3G: third-generation mobile telephone 4ESS Number 4 Electronic Switching System (Alcatel-Lucent) 4WTS: Four-wire termination set: US 5ESS Number 5 Electronic Switching System (Alcatel ...
The collection of addresses in the network is called the address space of the network. Examples of telecommunications networks include computer networks, the Internet, the public switched telephone network (PSTN), the global Telex network, the aeronautical ACARS network, [1] and the wireless radio networks of cell phone telecommunication providers.
Each station in this example is separated from its adjacent stations by 200 kHz, and the difference between 200 kHz and 180 kHz (20 kHz) is an engineering allowance for the imperfections in the communication system. In the example above, the free space channel has been divided into communications channels according to frequencies, and each ...
Some systems are designed for point-to-point line-of-sight communications, once two such nodes get too far apart they can no longer communicate. Other systems are designed to form a wireless mesh network using one of a variety of routing protocols. In a mesh network, when nodes get too far apart to communicate directly, they can still ...
The term wireless has been used twice in communications history, with slightly different meanings. It was initially used from about 1890 for the first radio transmitting and receiving technology, as in wireless telegraphy, until the new word radio replaced it around 1920.
A telegraph key, clacker, tapper or morse key is a specialized electrical switch used by a trained operator to transmit text messages in Morse code in a telegraphy system. [1] Keys are used in all forms of electrical telegraph systems, including landline (also called wire) telegraphy and radio (also called wireless) telegraphy .