| Data communications concerns itself with the transmission of information between computers. The framework that supports the transmissions is called a network. Networks can connect computers together with physical connections such as copper wire or fiber optic cable, or can be intangible in form such as with a wireless network which uses radio waves, or other parts of the energy spectrum, to perform data transmissions.
The aim of any communication network is simple
Minimize delay (or Maximize thruput)
Minimize Error
Try to do the above two with minimum power
The algorithms involved in encoding and decoding data reliably over a network are handled by transmission protocols. The most popular protocol used by the Internet is TCP/IP which stands for Transmission Control Protocol / Internet Protocol. However, there are countless other protocols used in data transmission and many are used on networks that exist outside the Internet.
History
The earliest computer networks were developed by the Advanced Research Projects Agency Network (ARPANET) of the U.S. Department of Defense. It was in the autumn of 1969 that the first ARPANET computer was connected to the ARPANET's IMP (Interface Message Processor) node at the University of California at Los Angeles (UCLA). Doug Engelbart's hypertext-project computer at Stanford Research Institute (SRI) was the next. By the end of the year, the network also included the computers at the University of California, Santa Barbara (UCSB) and the University of Utah, i.e. four in all. All the computers used different operating systems and they were able to talk to each other across the network with equal status |