NETWORK AND TELECOMMUNICATIONS

NETWORK

In information technology, a network are a series of points or nodes interconnected by communication paths. Networks can interconnect with other networks and contain subnetworks.  The most common topology or general configurations of networks include the Bus Network, Star Network, Token Ring Network, and Mesh topologies Network. Networks can also be characterized in terms of spatial distance as Local Area networks (LANs), Metropolitan Area Networks (MANs), and Wide Area Networks (WANs). A given network can also be characterized by the type of data transmission technology in use on it . For example, a TCP/IP or Systems Network Architecture network; by whether it carries voice, data, or both kindes of signals; by who can use the network (public or private); by the usual nature of its connections (dial-up ore switched, dedicated or nonswitched, or virtual connections); and by the types of physical links (for example, Fiber Optical Cable, Coaxial Cable, and  Twisted Pair Cable). Large telephone networks and networks using their infrastructure, such as the Internet have sharing and exchange arrangements with other companies so that larger networks are created.

TELECOMMUNICATION

Telecommunication are the transmission of signals over a distance for the purpose of communication. In earlier times, this may have involved the use of Smoke Signals, Drums, Semaphore, Flags or Heliograph. In modern times, telecommunication typically involves the use of electronic devices such as Telephones, Television, Radio or Computers.

The evolution in telecommunication: from wire to wireless

WIRED TECHNOLOGIES

(i.) Twisted Pair Wire

*Twisted pair wire is the most widely used medium for telecommunication. Twisted-pair wires are ordinary telephone wires which consist of two insulated copper wires twisted into pairs and are used for both voice and data transmission. The use of two wires twisted together helps to reduce crosstalk and electromagnetic induction. The transmission speed ranges from 2 million bits per second to 100 million bits per second.

(ii.) Coaxial Cable

*Coaxial cable is widely used for cable television systems, office buildings, and other worksites for local area networks. The cables consist of copper or aluminum wire wrapped with insulating layer typically of a flexible material with a high dielectric constant, all of which are surrounded by a conductive layer. The layers of insulation help minimize interference and distortion. Transmission speed range from 200 million to more than 500 million bits per second.

(iii.) Fiber-Optical Cable

*Optical fiber cable consists of one or more filaments of glass fiber wrapped in protective layers. It transmits light which can travel over extended distances without signal loss. Fiber-optic cables are not affected by electromagnetic radiation. Transmission speed may reach trillions of bits per second. The transmission speed of fiber optics is hundreds of times faster than for coaxial cables and thousands of times faster than for twisted-pair wire.

WIRELESS TECHNOLOGIES

(i.) Terrestrial Microwave

*Terrestrial microwaves use Earth-based transmitter and receiver. The equipment look similar to satellite dishes. Terrestrial microwaves use low-gigahertz range, which limits all communications to line-of-sight. Path between relay stations spaced approx. 30 miles apart. Microwave antennas are usually placed on top of buildings, towers, hills, and mountain peaks.

(ii.) Communications Satellites

*The satellites use microwave radio as their telecommunications medium which are not deflected by the Earth's atmosphere. The satellites are stationed in space, typically 22,000 miles above the equator. These Earth-orbiting systems are capable of receiving and relaying voice, data, and TV signals.

(iii.)Wireless LANs 

*Wireless local area network use a high-frequency radio technology similar to digital cellular and a low-frequency radio technology. Wireless LANs use spread spectrum technology to enable communication between multiple devices in a limited area. An example of open-standards wireless radio-wave technology is IEEE 802.11b.

(iv.)Bluetooth

*A short range wireless technology. Operate at approx. 1Mbps with range from 10 to 100 meters. Bluetooth is an open wireless protocol for data exchange over short distances.

(v.)The Wireless Web

*The wireless web refers to the use of the World Wide Web through equipments like cellular phones, pagers,PDAs, and other portable communications devices. The wireless web service offers anytime/anywhere connection.

DATA MANAGEMENT

A database are a collection of data organized in a manner that allows access, retrieval, and use of that data. Data are a collection of unprocessed items, which can include text, numbers, images, audio and video. For example, you can type text on a keyboard, talk into a computer’s microphone, transfer photos taken with a digital camera, and capture motion and sounds with a video camera and store the recordings on a computer.

CHARACTER

A bit are the smallest unit of data that a computer can process. Eight bits grouped together in a unit comprise a byte. In the ASCII and EBCDIC coding schemes, each bytes represents a single character, which can be a number (5), letter (S), punctuation mark (?), or other symbol (&). The Unicode coding scheme, by contrast, uses one or two bytes to represent a character.

FIELDS

A field can be define as a combination of one or more related character or bytes and it was the smallest unit of data. It represents an attribute of some entity. An entity was a generalized class of people, place, or things for which data are collected, stored, and maintained. Examples of entity include employees, inventory, and customer. Most organizations organize and store data as entities. An attribute was a characteristic of an entity. For example employee number, last name, first name, hires date and department numbers are attributes for an employee.

RECORD

A collection of related data fields was a record. By combining description of various aspects of an object or activity is obtained. For instance, an employee record is a collection of fields about one employee. One field would be the employee’s name, another address, and still others her phone number, pay rate, earning made to date, and so forth.

FILE

A collection of related records was a file. For example an employee file was a collection of all company employee records. Likewise, an inventory file are a collection of all inventory records for a particular company or organization. PC database software often refers to files as tables.

DATABASE

At the highest level of this hierarchy was database, a collection of integrated and related files. Together bits, character, fields, records files, and database from the hierarchy of data. Characters are combined to make a field, a field are combined to make a record, records are combined to make a file, and files are combined to make a database. A database houses not only these levels of data but the relationship among them.

The evolution of data management technology: from tradition file to warehouse.
THE TRADITIONAL APPROACH VERSUS THE DATABASE APPROACH

THE TRADITIONAL APPROACH

In early day, organizations are adaptive systems with constantly changing data and information needs. For any growing or changing business, managing data can become quite complicated. One of the most basic ways to manage data are via files. Because a file are a collection of related records, all records associated with a particular application can be collected and managed together in an application specific file. At one time, most organizations had numerous application data specific file; for example, customer records often were maintained in separate files, with each file relating to a specific process completed by the company, such as shipping and billing. This approach to data management, whereby separate data files are created and stored for each application program, is called the traditional approach to data management. For each particular application, one or more data files is created

PROBLEMS WITH TRADITIONAL FILE PROCESSING
1) Data redundancy

• independent data files included a lot of duplicated data
• duplicated data: the same data were recorded and stored in several files
• this data redundancy caused problems when data had to be updated

2) Lack of data integration

• having data in independent files made it difficult to provide end users with information for ad hoc request that required accessing stored in several different files

• special computer programs had to be written to retrieve data from each independent file

3) Data dependence

• the organization of files, their physical locations and storage hardware, and the application software used to access those files- depended on one another

4) Lack data integrity of standardization

• data elements to be defined differently by different end users and applications

THE DATABASE APPROACH

Because of the problem, associated with the traditional approach to data management, many managers wanted a more efficient and effective means of organizing data. The result was the database approach to data management. In a database approach, a pool of related data are shared by multiple application programs. Rather than having separate data files, each application uses a collection of data that are either joined or related in the database.

Database Management System

The database approach offers significant advantages over the traditional file-based approach. For one, by controlling data redundancy, the database approach can use storage space more efficiently and increase data integrity. The database approach can also provide an organization with increased flexibility in the use of data. Because data once kept in two files is now located in the same database, it was easier to locate and request data for many types of processing. A database also offers the ability to share data and information resources. This can be a critical factor in coordinating organization wide responses across diverse functional areas of corporation. In sharing data, however, some consistency should exits among software programs.

To use the database approach to data management, additional software- a database management system (DBMS) - are required. A DBMS consists of a group of programs that can be used as an interface between a database and the user or the database and application program. Typically, this software acts as a buffer between the application program and the database itself.

DATA WAREHOUSE

A data warehouse are a database that holds business information from many sources in the enterprise, covering all aspects of the company’s processes, products, and customers. The data warehouse provides business users with a multidimensional view of the data they need to analyze business condition. A data warehouse are designed specifically to support management decision making, not to meet the needs of transaction processing system. The data warehouse provides a specialized decisions support database that managers the flow of information from existing corporate database and external source to end user decision support applications. A data warehouse stores historical data that has been extracted from operational system and external data sources. This operational and external data is “clean up” to remove inconsistencies and integrated to create a new information database that was more suitable for business analysis.

DATA MART

A data mart are a subset of a data warehouse. Data marts bring the data warehouse concept- on-line analysis of sale, inventory, and other vital business data that has been gathered from transaction processing systems- to small and medium-sized businesses and to departments within large companies. Rather than store all enterprise data in one monolithic database, data marts contain a subset of the data for single aspect of a company’s business. In fact, there may be even be more detailed data for a specific area in a data mart than what a data warehouse would provide.

Applications and Data Marts

DATA MINING

Data mining are an information analysis too that involves the automated discovery of pattern and relationship in a data warehouse. Data mining represents the next step in the evolution of decision support system. It makes use of advanced statistical technique and machine learning to discover facts in a large database, including database on the internet.

Data Mining Process

The Data mining’s objective are to extract patterns, trends, and rules from data warehouse to evaluate proposed business strategies, which in turn will improve competitiveness, improve profits, and transforms business processes.

INFORMATION SYSTEM SOFTWARE

In general, software are the program consists of all the electronic instruction that tell the computer how to perform a task. Software can be divived into two categories, which is Application Software and System Software.

• Application Software are software that has been developed to solve a particular problem for user and perform useful work on sepcific tasks or to provide entertainment,it designed to make users more productive and assist them with personal tasks. 
• System Software consists the programs that control or mantain the operations of the computers and its devices. 

Appication software for business comes in two primary forms:

(1.) Custom Software: Are the software applications that are developed within an organization for use by that organization, it was owned by the organization that developed it.

(2.) Commercial off-the-shelf (COTS): Are the software developed with the intention of selling the software in multiple copies.

Application software includes a variety of programs that can be subdivided into general-purpose and application-specific categories. At here we would to discuss about the comparison between General Purpose Application Software and Function-Specific Application Software.

General-Purpose Application Software
General-purpose applications packages are programs that perform common information processing hobs for end users. For example, word processing programs, electronic spreadsheet programs, database management programs, graphics programs, communications programs, and integrated packages are popular with microcomputer users for home, education, business, scientific, and many other general purposes. They are also known as productivity packages, because they significantly increase the productivity of end users. This packaged software is also called off-the-shelf software packages, because these products are packaged and available for sale. Many features are common to most packaged programs.

Here are some example of the General-Purpose Application Program and its fuction.

(i.)Web Browsers - Example of browers such like Internet Explorer,  Mozilla Firefox,  The World, Opera, Safari, Netscape, Tencent Traveler, Maxthon and Chrome are software applications that support navigation through the point-and–click hyper-linked resources of the Web. Besides, it was used to gain access to Internet search engines. For examples: Google, Look Smart and Yahoo. People will using search engines to find the information and it had become an very indispensable part of Internet, Intranet, and extranet applications.

Web Browsers

(ii.)Electronic mail (E-Mail) - Are software to communicate by sending and receiving messages and attachments via the internet, intranet, or extranet. Such like Instant messaging (IM), it used to receive electronic messages instantly. Besides, such like weblog are kind of a personal website in dated log format and it can updated with new information about a subject or range of the subjects.

MSN                   &                Weblog

(iii.)Word Processing - Used to create, edit, revise, and print documents. For examples: Microsoft Word, Lotus wordpro and Corel WordPerfect.

Microsoft word

(iv.)Desktop Publishing - Produce printed materials that look professionally published. For examples: Adobe PageMaker, and Microsoft Publisher.

Adobe PageMaker

(v.)Electronic Spreadsheets - A type of computer software for performing mathematical computations on numbers arranged in rows and columns, in which the numbers can depend on the values in other rows and columns, allowing large numbers of calculations to be carried out simultaneously.

Spreadsheet

(vi.)Presentation Graphics - Common presentation graphics packages used to create multimedia presentations of graphics, photos, animations and video clips. For examples: Microsoft PowerPoint and Lotus Freelance. The top packages can tailor files and transfer in HTML format to websites.

Microsoft Power Point

(vii.) Database Software - Kind of software that provides tools for organizing data into a form that allows for efficient search and retrieval. Data related to a specific question of concern can be accessed using a database query.

Databas Software

(viii.)Personal Information Managers(PIM) - PIM are software package for end-user productivity and collaboration, as well as a popular application for personal digital assistant (PDA) handheld devices.

(ix.) Groupware - software that helps workgroups collaborate on group assignments.For examples: Windows SharePoint Services and WebSphere both allow teams to create websites for information sharing and document collaboration.

Function-Specific Application Software

Many application programs are available to support specific applications of end users. Such like Business Application Programs, it was the programs that accomplish the information processing tasks of important business functions or industry requirements. Besides, likeScientific Application Programs are the programs that perform information processing tasks for the natural, physical, social, and behavioral sciences, engineering and all other areas involved in scientific research, experimentation, and development. There are so many other application areas such as customer relationship management, enterprise resource planning, supply chain management, wed-enabled electronic commerce and etc.