Network and Telecommunications: The evolution in telecommunication: From wire to wireless.

Wireless communication is the transfer of information over a distance without the use of electrical conductors or "wires”. The distances involved may be short or long. It is convenient because it can connected without any wire.

The wireless technology was start in 1894 when an Italian physicist Guglielmo Marconi found a method of transmitting electromagnetic signals through the air. In 1912, Edwin Armstrong improved the Audion. He discovered that feeding the signal back the tube the power of the Audion could be increased. He continued experimentation resulted in the invention of Frequency modulation which is technology used in FM radio and other forms of wireless technology. In Frequency modulation one wave containing the information to be transmitted is combine with another wave, called a carrier wave, whose frequency is constant.In 1946 , Bell Laboratories connect the first wireless car phone to the St. Louis network. In 1962, Telstar Satellite successfully transmitted television and telephone conversation across the Atlantic for the first time.

Wired Communication refers to the transmission of data over a wire-based communication technology. Therefore communication devices cannot be connected if there is no wire to connect to another device. The early wired communication was used by Western Union Telegraph Company with the help of telegraph key to send Morse's famous telegraph message in 1856 . There are over two thousand telegraph offices operated across the United States. Wires criss-crossing cities and states and terminating in several exchanges(switching point) or central offices. Operators would connect the circuits and complete the call for the subscriber.In 1878, the first telephone exchange which connect 21 separated lines opened in New haven, Connecticut. In 1889 Almon Strowger developed the automatic switch called the step-by-step. In 1896 he replaced the button-pushing method with a rotary dialer. Then come to year 1913, N.J. Reynolds, a Western Electric engineer, developed a better automatic switch, the crossbar switch. It used a grid of horizontal and vertical bars, with electromagnets at their ends. The horizontal bars could rotate up and down ti connect to specific vertical bars and thus complete circuits. In the mid of 20 century AT & T integrated electronics into crossbar switches and in 1965, the first electronic switching system was used which can handled up to 65,000 two-way voice circuits. Until 1970 all telephone switches depended on a continuous physical connection to complete and maintain the call and new electronic switching device was put into service in 1976.

Data management: The evolution of data management technology: from traditional file to data warehouse.

Traditional File Based System (TFBS) is the first and the oldest database system that attempt to computerize the manual filing system. For example, in an organization, a manual files is set up to record all internal and external information include, employee, product, project, and customer. File-based system consists of many file with name label and keep in different location. It causes a lot of problem such as data redundancy, lack of idea integration, data dependence and lack of data integrity or standardization.


There are several advantages of Traditional File Based System (TFBS) :

• No need of external storage
• No need of highly technical person to handle the database
• Processing speed is high as compare to (Data Base Management System) DBMS
  

There are several disadvantages of Traditional File Based System (TFBS) :

• Provide less security
  
• Redundancy is more
• Less integrity
• High complexity in updating of database

Data warehouse is focuses on data storage. However, the means to retrieve and analyze data, to extract, transform and load data, and to manage the data dictionary are also considered essential components of a data warehousing system. many references to data warehousing use this broader context. Thus, an expanded definition for data warehousing includes business intelligence tools, tools to extract, transform, and load data into the repository, and tools to manage and retrieve meta data.

There are 4 type of database system which is :

• Operational databases
• Distributed data
  
• External databases
  
• Hypermedia database
  

IS Software: The comparison between general purpose application software and function-specific application software

General purpose application software packages are generally tools that provide specific capabilities, but not in support of a specific purpose. It is much broader in use. Word processors for example, can handle every form of writing, aside from calligraphy. Spreadsheet programs like Excel handle a significant portion of data processing problems (with databases taking the rest).

For Example, a spreadsheet program is a general purpose application software. It does spreadsheets, but those could be spreadsheets that you use to balance your checkbook, or manage your fantasy football league.

Special purpose application software is more limited in what it will do, but it usually goes that one thing much better than a general purpose program. Beside that, it also very specific in its use. Engineering programs often fall under this category - there is program that does slope stability analysis and nothing else, for instance. Special purpose software may also be created in house and tailored to the specific needs of the company.

For example, Turbo Tax ( a tab preparation package) is a special purpose application. Sure, it adds and subtracts numbers like a spreadsheet, but you can't use it to track your fantasy football league. It does one thing - prepare tax return.

In general, special purpose software is intended to perform a very specific function, while general purpose software is intended to perform a broader class of functions.

IS Hardware: The evolution of computer systems: from mainframe computer systems to microcomputer systems.

A mainframe computer is a large multi-user computer system (cost L500000 upwards) used as the central computer service of a large organization, it was a powerful computer, and it typically bulk the data processing such as the census, industry and consumer statistics, financial transaction process and etc. For example, Gas Board customer accounts. Large organization could have several mainframe and minicomputer systems, but both of this is possibly on different sites, linked by a communications network.

A microcomputer is a single user computer system (cost L2000 to L5000) based on an 8-bit microprocessor (Intel 8080, Zilog Z80, Motorola 6800). Its also a computer with a microprocessor ad its central processing unit. They are physically small compared to mainframe and minicomputers. It is used for small industrial (e.g. small control systems), office (e.g. word-processing, spreadsheets) and program development (e.g. schools, colleges) applications.