Overview of Telecommunications PDF

1.0 OVERVIEW OF TELECOMMUNICATIONS School of Education Faculty of Social Sciences and Humanities  1.1 INTRODUCTION TO TELECOMMUNICATION  Communication The message (data and information) is communicated via the signal. The transmission medium “carries”...

1.0 OVERVIEW OF TELECOMMUNICATIONS School of Education Faculty of Social Sciences and Humanities  1.1 INTRODUCTION TO TELECOMMUNICATION  Communication The message (data and information) is communicated via the signal. The transmission medium “carries” the signal. 3 Communication Process 4  Telecommunication The electronic transmission of signals for communications over a distance. For example: telephone, telegraph, television, radio, etc. Telecommunication Medium Anything that carries an electronic signal and interfaces between a sending device and a receiving device. 5  Telecommunication Medium Anything that carries an electronic signal and interfaces between a sending device and a receiving device. 6  Telecommunication Hardware Send and receive the signals employing telecommunications software that governs their operations such as repeaters, hubs, bridges, switches, routers and gateways 7  Telecommunication Software Software based on telecommunications protocols used to – control – monitor load – troubleshoot data – provide security that traveling over a telecommunications network. 8  1.2 HISTORY OF TELECOMMUNICATION TECHNOLOGIES 1642 AD - 1876 1890 - 1947 1952 - 1977 1981 - 1994 1998 - Current  1.3A INTERNET 16  Internet A global collection of network Interconnected computers work by transmitting data through a special type of packet switching which is known as the IP (internet protocol). When you connect to the Internet, your computer becomes part of a network. Internet VS WWW? 17  Browser Can be defined as a software application used to locate and display web. ❖ IE (Internet Explorer) ❖ Mozilla Firefox ❖ Safari ❖ Microsoft Edge  1.3B WEB SEARCHING  Web Searching ▪ World Wide Web (or WWW, It is called a “web” because the interconnections between documents resemble a spider’s web). ▪ Web is a software application that makes it easy and possible for nearly anyone to publish and browse hypertext documents on the Internet. ▪ Web searching is an act of looking for information in computer database or network (web). 20  Web Searching Categories 1. Directories 2. Search engines 3. Meta-search engines 4. Yellow pages 21  Directories ▪ A Web Directory or Web Guide is a hierarchical representation of hyperlinks. AOL – http://www.aol.com/ Excite – http://www.excite.com/ Lycos – www.lycos.com Yahoo! – www.yahoo.com Hotfrog - http://www.hotfrog.com.au/ 22  Search Engines ▪ A computer program that does the following: – Allows user to submit a query that consists of a word or phase. – Searches the database. – Returns a list of suitable URLs which match your query. – Allows user to revise and resubmit. 23  Meta-search Engines ▪ A search engine that queries other search engines and then combines the results that are received from all. In effect, the user is not using just one search engine but a combination of many search engines at once to optimize Web searching. http://www.search.com/ http://www.dogpile.com/ http://clusty.com/ 24  Yellow Pages ▪ The yellow pages are any telephone directory of businesses, organized by category rather than alphabetically by business name, and in which advertising is sold, while white pages contains individual directory. ❖ Bigfoot – www.bigfoot.com ❖ Yahoo! People Search – people.yahoo.com ❖ WhoWhere – www.whowhere.com ❖ Yellow Page Malaysia– http://www.yellowpages.com.my/ ❖ SuperPages – www.superpages.com 25  Directory vs Search Engine Directory Search Engine A directory allows you to explore and A search engine brings you to the get what you want eventually. exact page on the words or phrases you are looking for. Use a directory to find cooking- Use a search engine to find a specific related websites. recipe, by providing the name of the ingredients. Use a directory to find travel guides in Use a search engine to find the a country. transport trains schedule in South Africa.  Web Searching Techniques 1. Pattern Matching Queries 2. Boolean Queries  Pattern Matching Queries ▪ It is also called Fuzzy Query. ▪ You can enter “ungrammatical sentences”, “incomplete sentence fragments”, “disjoint phrases”, “nonsense words”. ▪ The search engine gets a collection of keywords. ▪ Required keyword: Mark with “+” before the keyword. ▪ Prohibited keyword: Mark with “-” before the keyword. ▪ Type in keywords +online learning and -online learning. Seek the difference. Pattern Matching Queries  Boolean Queries ▪ A Boolean Query is a query that consists keywords but with logical operators (AND, OR, NOT). ▪ X AND Y – will return URLs that contain both X and Y. ▪ X OR Y – will return URLs that contain either X or Y. ▪ X AND NOT Y – will return URLs that contain X and do not contain Y. ▪ Symbol: (AND - &), (OR - |), (NOT - !), (NEAR - ~)  1.3C WEB APPLICATIONS  Web Applications ▪ A Web application (Web app) is an application program that is stored on a remote server and delivered over the Internet through a browser interface. ▪ Web applications use a combination of server-side scripts (PHP and ASP) to handle the storage and retrieval of the information, and client-side scripts (JavaScript and HTML) to present information to users. 32  Web Applications Here's what a typical web application flow looks like: 1. User triggers a request to the web server over the Internet, either through a web browser or the application’s user interface 2. Web server forwards this request to the appropriate web application server 33  Web Applications 3. Web application server performs the requested task – such as querying the database or processing the data – then generates the results of the requested data 4. Web application server sends results to the web server with the requested information or processed data 5. Web server responds back to the client with the requested information that then appears on the user’s display 34  Web Applications Example of a web application ▪ Web applications include online forms, shopping carts, word processors, spreadsheets, video and photo editing, file conversion, file scanning, and email programs such as Gmail, Yahoo and AOL. ▪ Popular applications include Google Apps and Microsoft 365. Google Apps for Work has Gmail, Google Docs, Google Sheets, Google Slides, online storage and more. 35  Web Applications Example of a web application ▪ Other functionalities include online sharing of documents and calendars. This lets all team members access the same version of a document simultaneously. 36  Web Applications Benefits of a web application ▪ Web applications run on multiple platforms regardless of OS or device as long as the browser is compatible ▪ All users access the same version, eliminating any compatibility issues ▪ They are not installed on the hard drive, thus eliminating space limitations 37  Web Applications Benefits of a web application ▪ They reduce software piracy in subscription-based web applications (i.e. SaaS) ▪ They reduce costs for both the business and end user as there is less support and maintenance required by the business and lower requirements for the end user’s computer 38 That’s all for today 39