This kind of transmission is not really effective and takes longer then using network and there is not possible interactive processing of information.







General model of communication networks.






























Figure 1.0



Communication: Widely relative interactive information exchange between several objects

Element of traffic infrastructure

Ability to exchange electronic information between several objects

(electronic communication)



Network: Something broadband networking (widely manifold) on a surface

A completion of effectively lied objects in some space















The advantages of communication networks



Only need one main point to transmit data (TV, Radio)
















Figure 1.1

Sharing data both ways (Internet)






Figure 1.2

Sharing hardware and data (intranet)
















Figure 1.3



At its simplest, a computer network is two or more computers sharing information across a common transmission medium.





Figure 1.4

















Computer networks are developing in comparing with stand alone computers many advantages.



Sharing data


Sharing resources


Increased safety of system


Saving space






Data sharing is the main reason for building computers networks. The thing is that necessary data files could use more users at the same time. It is because data files are stored on network servers and connected users can access them. Resources sharing are allowing workstations using resources of network together. Usually sharing hard drives, printers, plotters, scanners, fax modems, cd-roms. Increased safety of system is another advantage of networks. When are all files stored on the server and workstations are loading files from server it is easier to manage security and backups of files. In case of workstation failure it is possible to continue work on another workstation. Saving space is common advantage of networks e. g. printer doesn’t need to be close to one computer ( usb line, lpt line) but we can put printer where it is suitable for us. This is especially using with servers and their backup when jukeboxes are stored in a safe place and it is not near server. A2. Compare current national and international communication networks.



The International Standards Organization (ISO)—whose name is

derived from the Greek prefix iso, meaning “same”—is located in

Geneva, Switzerland. ISO develops and publishes standards and

coordinates the activities of all national standardization bodies. In

1977, the ISO initiated efforts to design a communication standard

based on the open systems architecture theory from which

computer networks would be designed. This model came to be

known as the Open Systems Interconnection (OSI) model.





Network industry uses two types of standards:



De facto standards: arise through widespread commercial and educational use. These standards are often proprietary and usually remain unpublished and unavailable to outside vendors unknown as closed system standards e.g. IBM System Network Architecture



De jure standards: are non-proprietary standards which means that no single company creates them or owns rights to them. These standards are developed with the intend of enhancing connectivity and interoperability by making specifications public e. g. TCP/IP



Why we need standardization?



Standardization is needed because computers are using different operating systems or using different types of networks.

Communications between computers and network are being made on software level by protocols.

Protocols are formal specification that defines procedures to follow when transmitting or receiving data.