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Information about Information Transmission

Data transmission is the conveyance of any kind of information from one space to another. Historically this could be done by courier, a chain of bonfires or semaphores, and later by Morse code over copper wires.

In recent computer terms, it means sending a stream of bits or bytes from one location to another using any number of technologies, such as copper wire, optical fiber, laser, radio, or infra-red light. Practical examples include moving data from one storage device to another and accessing a website, which involves data transfer from web servers to a user's browser.

A related concept to data transmission is the data transmission protocol used to make the data transfer legible. Current protocols favor packet based communication.

Types of data transmission

Serial transmission bits are sent over a single wire individually. Whilst only one bit is sent at a time, high transfer rates are possible. This can be used over longer distances as a check digit or Parity bit can be sent along it easily.

Parallel transmission Multiple wires are used and transmit bits simultaneously and is much faster than Serial transmission as one byte can be sent rather than one bit. This method is used internally within the computer, for example the internal buses, and sometimes externally for such things as printers, however this method of transmission is only available over short distances as the signal will degrade and become unreadable, as there is more interference between many wires than between one.

Asynchronous and synchronous data transmission

Asynchronous transmission uses start and stop bits to signify the beginning ait ASCII character would actually be transmitted using 10 bits e.g.: A "0100 0001" would become "1 0100 0001 0". The extra one (or zero depending on parity bit) at the start and end of the transmission tells the receiver first that a character is coming and secondly that the character has ended. This method of transmission is used when data is sent intermittently as opposed to in a solid stream. In the previous example the start and stop bits are in bold. The start and stop bits must be of opposite polarity. This allows the receiver to recognize when the second packet of information is being sent.

Synchronous transmission uses no start and stop bits but instead synchronizes transmission speeds at both the receiving and sending end of the transmission using clock signals built into each component. A continual stream of data is then sent between the two nodes. Due to there being no start and stop bits the data transfer rate is quicker although more errors will occur, as the clocks will eventually get out of sync, and the receiving device would have the wrong time that had been agreed in protocol (computing) for sending/receiving data, so some bytes could become corrupted (by losing bits). Ways to get around this problem include re-synchronization of the clocks and use of check digits to ensure the byte is correctly interpreted and received.

Protocols and handshaking

Protocol A protocol is an agreed-upon format for transmitting data between two devices e.g.: computer and printer. All communications between devices require that the devices agree on the format of the data. The set of rules defining a format is called a protocol.

The protocol determines the following:
  • the type of error checking to be used if any e.g.: Check digit (and what type/ what formula to be used)
  • data compression method, if any e.g.: Zipped files if the file is large, like transfer across the Internet, LANs and WANs.
  • how the sending device will indicate that it has finished sending a message, e.g.: in a Communications port a spare wire would be used, for serial (USB) transfer start and stop digits maybe used.
  • how the receiving device will indicate that it has received a message
  • rate of transmission (in baud or bit rate)
  • whether transmission is to be synchronous or asynchronous
In addition, protocols can include sophisticated techniques for detecting and recovering from transmission errors and for encoding and decoding data.

Handshaking The process by which two devices initiate communications e.g.: a certain ASCII character or an interrupt signal/ request bus signal to the processor along the Control Bus. Handshaking begins when one device sends a message to another device indicating that it wants to establish a communications channel. The two devices then send several messages back and forth that enable them to agree on a communications protocol. Handshaking must occur before data transmission as it allows the protocol to be agreed.
Information is the result of processing, gathering, manipulating and organizing data in a way that adds to the knowledge of the receiver. In other words, it is the context in which data is taken.
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A courier is a person or company employed to deliver messages, packages and mail. Couriers are distinguished from ordinary mail services by features such as speed, security, tracking, signature, specialization and individualization of services, and committed delivery times, which
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semaphore or optical telegraph is an apparatus for conveying information by means of visual signals, with towers with pivoting blades or paddles, shutters, in a matrix, or hand-held flags etc.
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Morse code is a method for transmitting telegraphic information, using standardized sequences of short and long elements to represent the letters, numerals, punctuation and special characters of a message.
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A wire is a single, usually cylindrical, elongated strand of drawn metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals . Standard sizes are determined by various wire gauges.
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BIT is an acronym for:
  • Bannari amman Institute of Technology
  • Bangalore Institute of Technology
  • Beijing Institute of Technology
  • Benzisothiazolinone
  • Bilateral Investment Treaty
  • Bhilai Institute of Technology - Durg

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byte (pronounced /baɪt/) is a unit of measurement of information storage, most often consisting of eight bits. In many computer architectures it is a unit of memory addressing.
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2, 1
(mildly basic oxide)
Electronegativity 1.90 (Pauling scale)
Ionization energies
(more) 1st: 745.5 kJmol−1
2nd: 1957.9 kJmol−1
3rd: 3666 kJmol−1

Atomic radius 135 pm
Atomic radius (calc.
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A wire is a single, usually cylindrical, elongated strand of drawn metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals . Standard sizes are determined by various wire gauges.
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An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length. Fiber optics is the overlap of applied science and engineering concerned with such optical fibers.
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laser is a mechanical device that produces coherent radiation. The term "laser" is an acronym: Light Amplification by Stimulated Emission of Radiation.
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Radio is the wireless transmission of signals, by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space.
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Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. The name means "below red" (from the Latin infra, "below"), red being the color of visible light with the longest wavelength.
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Hard disk drive

An IBM hard disk drive with the metal cover removed. The platters are highly reflective.
Date Invented: September 13 1956
Invented By: An IBM team led by Reynold Johnson
Connects to:
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A website (alternatively, Web site or web site) is a collection of Web pages, images, videos or other digital assets that is hosted on one or several Web server(s), usually accessible via the Internet, cell phone or a LAN.
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web server can mean one of two things:
  1. A computer program that is responsible for accepting HTTP requests from clients, which are known as web browsers, and serving them HTTP responses along with optional data contents, which usually are web pages such as HTML documents and

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Browser can refer to:
  • A herbivore whose nutrition generally comes from high growing plants
  • A user interface on a computer that allows navigation of objects

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computing protocols, see Protocol (computing). For protocols on two-way voice communications, see Voice procedure. For other meanings of the word protocol, see Protocol.
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In telecommunication, serial transmission is the sequential transmission of the signal elements of a group representing a character or other entity of data. This kind of transmission is increasingly common in computing contexts, superseding the previously prevalent parallel
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A check digit is a form of redundancy check used for error detection, the decimal equivalent of a binary checksum. It consists of a single digit computed from the other digits in the message.
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A parity bit is a binary digit that indicates whether the number of bits with value of one in a given set of bits is even or odd. Parity bits are used as the simplest error detecting code.

There are two types of parity bits: even parity bit and odd parity bit.
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In telecommunication, parallel transmission is:
  1. The simultaneous transmission of the signal elements of a character or other data item.
  2. In digital communications, the simultaneous transmission of related signal elements over two or more separate paths.

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byte (pronounced /baɪt/) is a unit of measurement of information storage, most often consisting of eight bits. In many computer architectures it is a unit of memory addressing.
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BIT is an acronym for:
  • Bannari amman Institute of Technology
  • Bangalore Institute of Technology
  • Beijing Institute of Technology
  • Benzisothiazolinone
  • Bilateral Investment Treaty
  • Bhilai Institute of Technology - Durg

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American Standard Code for Information Interchange (ASCII), generally pronounced ask-ee IPA: /ˈæski/ ( [1] ), is a character encoding based on the English alphabet.
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A parity bit is a binary digit that indicates whether the number of bits with value of one in a given set of bits is even or odd. Parity bits are used as the simplest error detecting code.

There are two types of parity bits: even parity bit and odd parity bit.
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Circadian Locomotor Output Cycles Kaput, or Clock is a gene which encodes proteins regulating circadian rhythm. The CLOCK protein seems to affect both the persistence and length of the circadian cycle. CLOCK forms part of a basic-helix-loop-helix transcription factor.
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For other uses, see Data (disambiguation).


Debt, AIDS, Trade in Africa (or DATA) is a multinational non-government organization founded in January 2002 in London by U2's Bono along with Bobby Shriver and activists from the Jubilee 2000 Drop
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BIT is an acronym for:
  • Bannari amman Institute of Technology
  • Bangalore Institute of Technology
  • Beijing Institute of Technology
  • Benzisothiazolinone
  • Bilateral Investment Treaty
  • Bhilai Institute of Technology - Durg

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protocol is a convention or standard that controls or enables the connection, communication, and data transfer between two computing endpoints. In its simplest form, a protocol can be defined as the rules governing the syntax, semantics, and synchronization of communication.
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