Communication technologies


Communication is a process that allows beings - in particular humans - to exchange information by one of several methods. Communication requires that some kinds of symbols from a kind of language are exchanged. There are auditory means, such as speaking or singing, and nonverbal, physical means, such as body language, sign language, paralanguage, touch or eye contact.
Communication happens at many levels (even for one single action), in many different ways, and for all beings, and some machines. Many or all, fields of study dedicate some attention to communication, so when speaking about

communication it is very important to be sure about what aspect of communication one is speaking about. Some definitions are broad, recognizing that animals can communicate with each other as well as human beings, and some are more narrow, only including human beings within the parameters of human symbolic interaction.
Note: - Between parties, communication content include acts that declare knowledge and experiences, give advice and commands, and ask questions. These acts may take many forms, including all variations of nonverbal communication. The form depends on the symbol systems used. Together, communication content and form make messages that are sent towards a destination. The target can be oneself, another person (in interpersonal communication), or another entity (such as a corporation or group).

Communication as information transmission

Communication can be seen as processes of information transmission governed by three levels of semiotic rules: Syntactic (formal properties of signs and symbols), pragmatic (concerned with the relations between signs/expressions and their users) and semantic (study of relationships between signs and symbols and what they represent). Therefore, communication is a kind of social interaction where at least two interacting agents share a common set of signs and a common set of semiotic rules. (This commonly held rule essentially ignores autocommunication, including intrapersonal communication via diaries or self-talk)
In a simplistic model, information or content (e.g. a message in natural language) is sent in some form (as spoken language) from a emisor/sender/encoder to a destination/receiver/decoder. In a slightly more complex form a sender and a receiver are linked reciprocally
Telecommunication is the transmission of signals over a distance for the purpose of communication. In modern times, this process typically involves the sending of electromagnetic waves by electronic transmitters, but in earlier yars it may have involved the use of smoke signals, drums or semaphore. Today, telecommunication is widespread and devices that assist the process, such as the television, radio and telephone, are common in many parts of the world. There are also many networks that connect these devices, including computer networks, public telephone networks, radio networs and television networks. Computer communication across the Internet is one of many examples of telecommunication.
Telecommunication systems are generally designed by telecommunication engineers. Early inventors in the field include Alexander Bell, Guglielmo Marconi and John Logie Baird. Telecommunication is an important part of the world economy with the telecommunication industry's revenue being placed at just under 3% of

Analogue or digital
Signals can either be analogue or digital. In an analogue signal, the signal is varied continuously with respect to the information. In a digital signal, the information is encoded as a set of discrete values (e.g. 1's and 0's). During transmission, the information contained in analogue signals will be degraded by noise. Conversely, unless the noise exceeds a certain threshold, the information contained in digital signals will remain intact. This represents a key advantage of digital signals over analogue signals.

Networks

A collection of transmitters, receivers or transceivers that communicate with each other is known as a networks. Digital networks may consist of one or more routers that route data to the correct user. An analogue network may consist of one or more switches that establish a connection between two or more users. For both types of network, a repeater may be necessary to amplify or recreate the signal when it is being transmitted over long distances. This is to combat attenuation that can render the signal indistinguishable from noise.

A local area network

Despite the growth of the Internet, the characteristics of local area networks (computer networks that run at most a few kilometres) remain distinct. This is because networks on this scale do not require all the features associated with larger networks and are often more cost-effective and efficient without them

Channels

A channel is a division in a transmission medium so that it can be used to send multiple streams of information. For example, a radio station may broadcast at 96 MHz while another radio station may broadcast at 94.5 MHz. In this case the medium has been divided by frequency and each channel received a separate frequency to broadcast on. Alternatively, one could allocate each channel a recurring segment of time over which to broadcast — this is known as time-division multiplexing and is sometimes used in digital communication.

Modulation

The shaping of a signal to convey information is known as modulation. Modulation can be used to represent a digital message as an analogue waveform. This is known as keying and several keying techniques exist (these include phase-shift keying, frequency-shift keying and amplitude-shift keying. Bluetooth, for example, uses phase-shift keying to exchange information between devices.
Modulation can also be used to transmit the information of analogue signals at higher frequencies. This is helpful because low-frequency analogue signals cannot be effectively transmitted over free space. Hence the information from a low-frequency analogue signal must be superimposed on a higher-frequency signal (known as a carrier wave) before transmission. There are several different modulation schemes available to achieve this (two of the most basic being amplitude modulation and frequency modulation). An example of this process in action is a DJ's voice being superimposed on a 96 MHz carrier wave using frequency modulation (the voice would then be received on a radio as the channel “96 FM”).[

Internet

The Internet is a worldwide network of computers that mostly operates over the public switched telephone network. Any computer on the Internet has a unique IP address that can be used by other computers to route information to it. Hence any computer on the Internet can send a message to any other computer using its IP address. These messages carry with them the originating computer's IP address allowing for two-way communication. In this way, the Internet can be seen as an exchange of messages between computers.An estimated 16.9% of the world population has access to the Internet with the highest access rates (measured as a percentage of the population) in North America (69.7%), Oceania/Australia (53.5%) and Europe (38.9%). In terms of broadband access, countries such as Iceland (26.7%), South Korea (25.4%) and the Netherlands (25.3%) lead the world.
The Internet works in part because of protocols that govern how the computers and routers communicate with each other. The nature of computer network communication lends itself to a layered approach where individual protocols in the protocol stack run largely independently of other protocols. This allows lower-level protocols to be customized for the network situation while not changing the way higher-level protocols operate. A practical example of why this is important is because it allows an Internet browser to run the same code regardless of whether the computer it is running on is connected to the Internet through an Ethernet or Wi-Fi connection. Protocols are often talked about in terms of their place in the OSI reference model — a model that emerged in 1983 as the first step in an unsuccessful attempt to build a universally adopted networking protocol suite.The model itself is outlined in the picture to the right. Although the Internet's protocol suite does not strictly adhere to this model, it can still be talked about in the context of this model

ARPANET development centred around the Request for Comment process and on April 7, 1969, RFC 1 was published. This process is important because ARPANET would eventually merge with other networks to form the Internet and many of the protocols the Internet relies upon today were specified through the Request for Comment process. In September 1981, RFC 791 introduced the Internet Protocol v4 (IPv4) and RFC 793 introduced the Transmission Control Protocol (TCP) — thus creating the TCP/IP protocol that much of the Internet relies upon today.
However not all important developments were made through the Request for Comment process. Two popular link protocols for local area networks (LANs) also appeared in the 1970s. A patent for the token ring protocol was filed by Olof Soderblom on October 29, 1974 and a paper on the Ethernet protocol was published by Robert Metcalfe and David Boggs in the July 1976 issue of Communications of the Acm.
Example: Communication Technologies, Inc. (COMTek) is a leading-edge company focusing on Telecommunications/Broadband, IT Managed Services, and Training. COMTek leverages its advanced technology experience and expertise to help clients turn IT challenges into business opportunities.
http://www.comtechnologies.com/
personal experience:-All the companies now a days are using Internet or Intranet for the information sharing and for the world wide knowledge.As dell computers uses Internet for their supply-chain management.Even now a days companies can not survive in cut-throught competition if they don’t share knowledge.

References:-

Ø http://en.wikipedia.org/wiki/Communication
Ø http://web.ebscohost.com/ehost/detail?vid=5&hid=20&sid=4d722e53-c725-4f19-a0fe-60f86638c88b%40sessionmgr3
Ø Baumeister, R. F., & Leary, M. R. (1995). The need to belong: Desire for interpersonal attachments as a fundamental human motivation. Psychological Bulletin 117, 497-529.