Educational Technology

INTERNET AND ITS APPLICATIONS

The Internet is the largest set of computer networks that use the Internet Protocol. The invention and development of the Internet was the biggest discovery by mankind in the 20th century that led to a revolution. Today, the Internet is used by more than 50% of the world population, as its applications are found in nearly every fields of life, be it communication, knowledge, news, shopping, marketing, entertainment, education, etc.
           The fast and relatively low-cost access is one of the major benefits of Internet to people and students all over the world, as getting an Internet connection is easy. Communication and information are the two basic uses of the Internet. Information available on websites can be updated or modified at any time and for any number of times, which helps in learning and better understanding.
           The internet is used mainly for communication, to gather information, education, entertainment, current affairs, online learning, commerce, publishing, etc.
In the usage of internet, publishing is not just used for organization or businesses; anyone can create their own web sites and publish their information or files on the Worldwide Web.
 It is a global collection of computer network, which help    in exchanging data using a computer. Through the Internet, thousands of people around the world are able to access information from their homes, schools, internet cafes and workplaces.

Internet in education cannot be denied, and hence, every student should be given access to the Internet for deeper understanding and knowledge of a subject. However, lots and lots of information can be termed as both, advantages and disadvantages of the Internet as students can also have an access to unwanted or unethical information and sites. Therefore, it is only wise for parents to make students understand what is good and what not for them, or keep a watch on their surfing (web browsing).

Definition for Internet

There are different definitions for internet but the meaning is the same as shown below
Def 1: The series of interconnected network allowing communication of data surrounded by millions of computers worldwide.
Def 2: A global communication network that allows computers worldwide to connect and exchange information.
Def 3: A worldwide system of computer network, a network of networks in which users at any one computer can get information from any other computer.
Meaning:

The word “Internet” exactly means “network of networks”. The Internet  consists of thousands of smaller regional networks spread throughout the world. It connects approximately 80 million users in Asian countries on any given day.
The Internet is referred as a physical part of the global network. It is a giant collection of cables and computers. No one “owns” the Internet, though there are companies that help out to manage different parts of the networks that tie everything together, there is no single governing body that controls what happens on the Internet. The networks within different countries sponsor the finance and manage according to the local procedure.

World Wide Web (WWW)

Generally, everyone thinks that the internet and web are same, but it is false.
The web is a software application or services that run on the internet. It is a collection of documents and resources. It is one of the fastest growing parts of the internet. It provides easy access to a huge range of information that is stored on computers around the world. 

Web site

Web site contains one to millions of inter connected pages, has hyperlinks to connect and help to find your way around the web site. You can find different kinds of information on the web- like games, health matters, holiday destination, train timetables, weather forecast and many more. There are  millions of web sites available on the internet, and you can find any thing that interests you. 

Web Address

Each Web site has its own unique address, which is called a Uniform Resource Locator or URL. To visit a site, you need to type its address in the address bar of your web browser.

Usage of Internet

• Internet users can share information in a variety of forms.
• The user can connect easily through ordinary personal computers and share the knowledge, thoughts by making the use of an internet.
• We can send electronic mail (e-Mail) to family members and friends with accounts on the Internet, which is similar to sending letters by post. The E-mail can be sent within minutes no matter where they are without postal stamps etc.
• We can post information that can be accessed by others and can update it frequently.
• We can access multimedia information that includes video, audio, and images.
• We can learn through Web-Based Training and Distance Learning on the internet.

Need

• Education is a life long process therefore anytime anywhere access to it is the need
• Information explosion is an ever increasing phenomena therefore there is need to get access to this information
• Education should meet the needs of variety of learners and therefore IT is important in meeting this need
• It is a requirement of the society that the individuals should posses technological literacy
• We need to increase access and bring down the cost of education to meet the challenges of illiteracy and poverty-IT is the answer

Importance

• access to variety of learning resources
• immediacy to information
• anytime learning
• anywhere learning
• collaborative learning
• multimedia approach to education
• authentic and up to date information
• access to online libraries
• teaching of different subjects made interesting
• educational data storage
• distance education
• access to the source of information
• multiple communication channels-e-mail,chat,forum,blogs,etc.
• access to open courseware
• better accesses to children with disabilities
• reduces time on many routine tasks

Benefits of Internet

• The internet is data and information loaded, including a range of medium.
• The Search engines that are available online are, fast and powerful.
• The internet is easy to use.
• We can become researchers because of easier access to data.
• People are motivated to share  their work online with the world.
• The internet appeals to different learning styles.
• Unlike paper the web can present dynamic data sources which change over time.
• The characters in an e-Mail don't get transposed or mixed up when they are sent over long distances.
• We can access  libraries around the world.

Features of Internet 

Geographic Sharing

The geographic sharing of the internet continues to spread, around the world and even beyond. A main feature of the Internet is that once you have connected to any part of it, you can communicate with all of it.

Architecture

The architecture of internet is most ever communication network designed. The failure of individual computers or networks will not affect its overall reliability. The information will not change or destroy over time or while transferring in between sites. 

Universal Access

It is easy to access and make the information like text, audio, video and also accessible to a worldwide people at a very low price.  Access to  internet is same to everyone no matter where they are. One can connect to any computer in the world, and  go to many excited places without leaving your chairs.

Use of the Internet in Education

✔ Using Multimedia
Arguably, it is believed that visual data has a greater impact on learning and memorizing than plain text. Therefore, images, graphics, animation, pictures, slides, documentaries, etc., have a greater appeal than a plain textbook. Using multimedia and Internet provides an opportunity for children to gain knowledge about a particular subject in depth. Students can now see the actual photographs of rare bird species, or see animated graphics of a volcanic eruption to understand the concept in detail.

✔ Online Learning
Another positive effect of Internet in education is the onset of distance education or online education (internet-based training (IBT) or web-based training (WBT)). With this facility, you can take up short-term courses with the course material available online, attend virtual classes, learn, and appear for exams. One of the benefits of online learning is that people from any part of the world can gain knowledge on different subjects, complete courses, etc.

✔ Easy Contact
Students can contact other students or their teachers via the e-mail if they have queries about any information. Sharing of information, discussions on a particular subject, etc., can be easily carried out using the Internet. At the same time, teachers can also contact parents and guardians easily using Internet.

✔ School/College Projects
Using the Internet can be very useful for completing projects in schools and colleges. As the Internet is an ocean of information, covering nearly all subjects known to man, one can find information, research work, etc., required for one's projects. Going through the information on the Internet is definitely faster than reading an entire book on the subject. Completing homework is also easier with the help of the Internet.

✔Encyclopedia
Sometimes, an encyclopedia may not always be available to students and they may have difficulty in gaining access to the books in the library. In that case, the encyclopedia of various subjects available on the Internet can be helpful. This is more useful for students who belong to communities not having English as their mother tongue. Kids and younger children can also be benefited by the Internet by using the pictures, videos, etc.

✔ News
All the latest news are constantly updated on the Internet on news websites. Students learning politics, can have an access to all the current affairs through the Internet. Historical accounts like speeches, biographies, archive videos and photographs, etc., are also easily available on the Internet in detailed and accurate versions.

✔ Affordable Knowledge
Investing in research material may be tedious and unaffordable for some. But, now, thanks to the Internet, we have content websites, web encyclopedias, and dictionaries whenever we want them. Today, able as well as less-able students can be benefited to the sea of knowledge through the Internet. University courses and learning is now easy for people belonging to all strata of the society with the help of online courses.

✔ Easy Education System
Not only gaining knowledge, but, every part of the education system is simplified because of the Internet. You can now view your prospective educational institute, look up for courses, enroll to online courses, take classes, research, see your results, and even look for job prospects on the Internet. Therefore, the scope of Internet in education is very wide and equal to all.

✔ No Age Bracket for Education
Online courses provide an opportunity for people of all age groups to take up education of their choice, according to their liking and wish. Be it a student, a housewife, or a professional, they can just start up their computers, connect to the Internet, and take virtual classes. Therefore, people can now gain knowledge according to their need and time available. You are, now, never too old or too busy to learn something new.

Facilities available for Communication System:

Email

Email is electronic mail.

Email is like sending a letter, only you send the message over the internet and it gets to the other person's email account within seconds.

If you have an email address, you can email anyone else who has an email address, including government agencies and lots of different kinds of businesses.

You'll create one or more email addresses when you open a new email account. Just like website addresses, every email address must be unique. So, when you create a new email account, you'll have to pick email addresses that haven't already been chosen by someone else.

Email accounts

Once you've got an email account, you can store your emails on the internet, or store them on a computer, laptop or another internet-connected device.

If your email is stored on the web, it's called 'webmail'.

To access a webmail account, you get onto the internet, go to the website where your webmail is hosted and 'log in' or 'sign in' with your username and password.

You can also have an email account where your emails are stored on an internet-connected device like a desktop computer, laptop or tablet. This way, you'll access your email with special software usually called an 'email client'.

Your email account username and password are usually saved in the software so you might not have to sign in each time you use email.

Even if your email is stored on a desktop computer, you can usually also set up webmail access. This lets you send emails and check for new emails from any internet-connected computer, which is useful for when you're not at home or away on holidays.

You shouldn't have any problems logging onto your webmail from any internet-connected device, but you should consider how secure the device is because we often end up emailing private or personal information.

Email addresses

Email addresses use a standard formula. They are always separated into two parts by the @ symbol.

The first part of the email address usually identifies you in some way. You might have your real name for the first part of your email address, or you could use a handle or a nickname that your friends and family will recognise.

The second part of an email address usually comes from your webmail provider or the internet service provider you use. If you're emailing someone and they, or their business has a website, you'll see that the second part of their email address uses part of their website address.

This gives a standard formula for all email addresses which will look something like firstname.surname@somewhere.com.au or yournickname@somewhere.com.au

Some people have two or more email addresses, one just to give to friends and family, one for a work or student email account, and sometimes another email address that can just be used to give to people you don't know—like when you sign up for email newsletters or for communicating with online businesses you don't know.

Using email

All email accounts have the same basic features.

They will have an 'inbox' for the emails you've received. There will also be a 'sent' items folder where the emails that you've sent to other people can be saved.

And there will be an 'address book' or contacts list where you can save other people's email addresses.

Sending emails

From the inbox, you can create new emails to send to people. Creating a new email might be called 'compose', 'create', or 'new email'.

To send an email, you type the email address or email addresses into the 'to' field. There is usually also a 'cc' field and a 'bcc' field showing that you can use to send copies of this email to other people.

In the subject field, you usually tell the other person what the email is about and then write the email in the body field. You can also attach files to emails including photos and documents.

When you click send, the email is sent to the other person's email account over the internet. They'll get your email the next time they log into their account.

If the email didn't reach the other person, you'll usually get an automated email telling you that the email was undeliverable.

This could be because the email address was spelled in correctly, you accidently included spaces, or sometimes it's because the other person's inbox is full and can't receive any more emails until they delete some emails to make space for new ones.

Replying to and forwarding emails

If someone emails you, you can reply to them by selecting the 'reply' button. You then write back to them and then select 'send'.

And if you receive an email that you'd like to share with someone else, you can forward the email to other people by selecting the 'forward' button, putting in the other people's email addresses, typing in a message and selecting 'send'.

Blog

Blog  – a journal or diary that is on the Internet.

Blogger  – a person who keeps a blog – Bloggers are revolutionizing the way news is shared.

Blogging – the action of writing a blog – Blogging is my way of sharing my passions with the world.

Blog Definition:

A blog (also called a weblog) is a website consisting of entries (also called posts) appearing in reverse chronological order with the most recent entry appearing first (similar in format to a daily journal).

Blogs typically include features such as comments and links to increase user interactivity. Blogs are created using specific publishing software.

TYPES OF BLOGS

There are many different types of blogs, differing not only in the type of content, but also in the way that content is delivered or written.

Personal blogs - The personal blog is an ongoing diary or commentary written by an individual.

Collaborative blogs or group blogs

A type of weblog in which posts are written and published by more than one author. The majority of high-profile collaborative blogs are based around a single uniting theme, such as politics or technology

Micro blogging

Micro blogging is the practice of posting small pieces of digital content—which could be text, pictures, links, short videos, or other media—on the Internet. Micro blogging offers a portable communication mode that feels organic and spontaneous to many and has captured the public imagination. Friends use it to keep in touch, business associates use it to coordinate meetings or share useful resources, and celebrities and politicians (or their publicists) micro blog about concert dates, lectures, book releases, or tour schedules. Examples of these include Twitter, Facebook, Tumblr, and by far the largest Wei Bo.

Corporate and organizational blogs

A blog can be private, as in most cases, or it can be for business purposes. Blogs used internally to enhance the communication and culture in a corporation or externally for marketing, branding or public relations purposes are called corporate blogs. Similar blogs for clubs and societies are called club blogs, group blogs, or by similar names; typical use is to inform members and other interested parties of club and member activities.

Aggregated blogs

Individuals or organization may aggregate selected feeds on specific topic or product and provide combined view for its readers. This allows readers to concentrate on reading instead of searching for quality on-topic content and managing subscription.

By genre

Some blogs focus on a particular subject, such as political blogs, health blogs, travel blogs (also known as travelogs), gardening blogs, house blogs, book blogs, fashion blogs, beauty blogs, lifestyle blogs, wedding blogs, project blogs, education blogs, niche blogs, classical music blogs, quizzing blogs, legal blogs are dreamlogs.  A blog featuring discussions especially about home and family is not uncommonly called a mom blog. While not a legitimate type of blog, one used for the sole purpose of spamming is known as a Splog.

By media type

A blog comprising videos is called a vlog, one comprising links is called a linklog, a site containing a portfolio of sketches is called a sketch blog or one comprising photos is called a photo blog. Blogs with shorter posts and mixed media types are called tumble blogs. Blogs that are written on typewriters and then scanned are called typecast or typecast blogs. A rare type of blog hosted on the Gopher Protocol is known as a phlog.

By device

A blog can also be defined by which type of device is used to compose it. A blog written by a mobile device like a mobile phone could be called amoblog.

Reverse blog

A reverse blog is composed by its users rather than a single blogger. This system has the characteristics of a blog, and the writing of several authors. These can be written by several contributing authors on a topic, or opened up for anyone to write. There is typically some limit to the number of entries to keep it from operating like a web forum.

CHATS

The medium of chat is descended from talk, but the terms (and the media)have been distinct since at least the early 1990s. Talk is prototypically for a small number of people, generally with no provision for channels. In chatsystems, however, there are many channels in which any number of peoplecan talk; and users may send private (one to one) messages. Some early chat systems (in use 1998) include IRC, ICQ and Palace. More recent alternatives include MSN Messenger and Google Talk. 

Chat systems have given rise to a distinctive style combining theimmediacy of talking with all the precision (and verbosity) that writtenlanguage entails. It is difficult to communicate inflection; th-ough conventions have arisen to help with this. 

Chats

• Talk in a friendly and informal way.
• An informal conversation.

Chat is a text-based communication that is live or in real-time. Once a chat has been initiated, either user can enter text by typing on the keyboard and the entered text will appear on the other user's monitor. Most networks and online services offer a chat feature. For example, when talking to someone in chat any typed text is received by other participants immediately. This is different from other text-based communications such as e-mail where it could be a couple of hours, days, or weeks to receive a response.

There are also several million users chatting through other networks such as IRC. A good example of a chat on IRC is the Computer Hope chat. A chat can also be conducted using sound or sound and video, assuming you have the bandwidth access and the appropriate programming.

Chat Advantages

To get connected to your old buddies chatting is the best option. Chatting has linked so many people especially the singles who are in search of people of their type means who want share a common view , people who think the same way .Instead of talking over the telephone they prefer a chat. Chatting apart from making friends also gives an opportunity to know the culture and tradition of the person from the other country. Online chatting has made its way out and has entertained the public in large.

Chat Disadvantages

The worst part is that while on a chat you are not sure of the person you are talking to. He might hide his true status like he is married or he is a bachelor. Chances of dishonesty are more. One can avoid these mishaps with the help of education and having good knowledge. To make sure that wrong things do not take place you have to be sure of the actions that you take. Like on a first on line chat do not tell things about you, follow a step by step procedure. Do not rely on the unknown person so much that you might land up taking a risk. And do not expect the same from the person you are chatting with. One needs to be extra careful all the time.

An Instant Messenger

These days to make a communication happen there are instant messengers with the help of these instant messengers the messages can be sent across. Instant messaging is one of the ways of chat. How these messengers work there is an option of a group chat where three people at a time can chat to start chatting one has to keep a nick name on that basis he or she will be recognized. To indulge one’s self into chatting software should be downloaded and once that is done with the help of the nick name you can almost invite anyone and everyone for a chat. Though invitation is not required as such because one’s a chat id has been made and if the person is online so his online status will be visible and he can be contacted or can contact the other person for a chat.

There are other two types of messengers the IRC and IQC. They also help in the same way. IRC: The IRC is internet relay chat. Internet relay chat is a type of text messaging which is basically made for people, who want to indulge in group discussions; it gives you an option of private messaging and also helps in file sharing.

IQC: IQC is I seek you. I seek you is not like g talk or other messengers in fact it helps in looking for old and new buddies. That’s why it is known as I seek you. IQC i.e. is a real discovery in the field of instant messaging. When the concept of chatting started I seek you was the only instant messenger used by the clients and the customers. Its working is based o n a graphical user interface i.e. GUI.

There are millions of types of chats.  If you mean chat websites... there are: 

~ XAT.com 
~ Facebook.com 
~ Clubpenguin.com 
~ Bearville.com 
~ PixieHollow.com 
~ Poptropica.com 
~ Myspace.com 
~ Webkinz.com 
~ Skype.com 
These are just some of the world's greatest chat websites. Most of these are from Disney, and the most common on the internet. (One of these is video chatting.) 

Types of Chat

The Classic Chat:

In a normal, not moderated chat, all speakers and participants (candidates) in the chat room see all the entries of the other participants, in real-time. They all see the same thing. As soon as a question / answer / comment is entered, it appears on the chat room, visible by all, at the bottom of the screen.

The Moderated Chat

In a moderated chat, speakers and participants (candidates) do not see the same thing. The questions / comments of the participants need to be validated by the speakers before they become visible by the other participants in the chat room. The speakers therefore can see what the participants see, plus the questions / comments that are pending. They can then allow them, reply to them, or delete them.

Manual Chat - A kind of chat where you choose your words and phrases 

Instant Chat - A kind of chat where you type in what you want to say but it has to be checked first 

Safe Open Chat - The best type of chat [in peoples' opinions] where you type whatever you want, no monitoring. 

Real time chat: Online users can chat in real time and the messages are sent and received within seconds.

Asynchronous chat: Users can read and post messages. Other users can reply to these messages whenever they read it. Communication does not happen in real time.

Internet Relay Chat (IRC): IRC is a type of real time chat where an IRC program is used to connect to a central IRC server. A user can pick a channel as per their likings and can start chatting.

Web based chat: It is a real time chat where users can chat in a particular website by using a browser.

NEWS GROUPS

Usenet was conceived in 1979, and publicly established in 1980, at the University of North Carolina at Chapel Hill and Duke University, over a decade before the World Wide Web was developed and the general public received access to the Internet, making it one of the oldest computer network communications systems still in widespread use.

Usenet, also commonly known as Usenet Newsgroups

The articles that users post to Usenet are organized into topical categories called newsgroups.

Organization (The "Big Nine" hierarchies of Usenet)

The major set of worldwide newsgroups is contained within nine hierarchies, eight of which are operated under consensual guidelines that govern their administration and naming. The current Big Eight are:

·         comp.* – computer-related discussions (comp.software, comp.sys.amiga)

·         humanities.*  fine arts, literature

·         and philosophy (humanities.classics, humanities.design.misc)

·         misc.* – miscellaneous topics (misc.education, misc.forsale, misc.kids)

·         news.* – discussions and announcements about news (meaning Usenet, not current events)   (news.groups,news.admin)

·         rec.* – recreation and entertainment (rec.music, rec.arts.movies)

·         sci.* – science related discussions (sci.psychology, sci.research)

·         soc.* – social discussions (soc.college.org, soc.culture.african)

·         talk.* – talk about various controversial topics (talk.religion, talk.politics, talk.origins)

Ø  In most newsgroups, the majority of the articles are responses to some other article. The set of articles that can be traced to one single non-reply article is called a thread. Most modern newsreaders display the articles arranged into threads and sub threads.

Ø  When a user posts an article, it is initially only available on that user's news server. Each news server talks to one or more other servers (its "newsfeeds") and exchanges articles with them. In this fashion, the article is copied from server to server and should eventually reach every server in the network. The later peer-to-peer networks operate on a similar principle, but for Usenet it is normally the sender, rather than the receiver, who initiates transfers. Usenet was designed under conditions when networks were much slower and not always available. Many sites on the original Usenet network would connect only once or twice a day to batch-transfer messages in and out. This is largely because the POTS network was typically used for transfers, and phone charges were lower at night.

Ø  Usenet has significant cultural importance in the networked world, having given rise to, or popularized, many widely recognized concepts and terms such as "FAQ", "flame", and "spam".

Newsreaders

Newsgroups are typically accessed with newsreaders: applications that allow users to read and reply to postings in newsgroups. These applications act as clients to one or more news servers. Modern mail clients or "communication suites" commonly also have an integrated newsreader. Often, however, these integrated clients are of low quality, compared to standalone newsreaders, and incorrectly implement Usenet protocols, standards and conventions. Many of these integrated clients, for example the one in Microsoft's Outlook Express, are disliked by purists because of their misbehavior

With the rise of the World Wide Web (WWW), web front-ends (web2news) have become more common. Web front ends have lowered the technical entry barrier requirements to that of one application and no Usenet NNTP server account. There are numerous websites now offering web based gateways to Usenet groups, although some people have begun filtering messages made by some of the web interfaces for one reason or another.  is one such web based front end and some web browsers can access Google Groups via news: protocol links directly.

Moderated and unmoderated newsgroups

Moderated newsgroups

A minority of newsgroups are moderated, meaning that messages submitted by readers are not distributed directly to Usenet, but instead are emailed to the moderators of the newsgroup for approval. The moderator is to receive submitted articles, review them, and inject approved articles so that they can be properly propagated worldwide. Articles approved by a moderator must bear the Approved: header line. Moderators ensure that the messages that readers see in the newsgroup conform to the charter of the newsgroup, though they are not required to follow any such rules or guidelines. Typically, moderators are appointed in the proposal for the newsgroup, and changes of moderators follow a succession plan.

Unmoderated newsgroups

Unmoderated newsgroups form the majority of Usenet newsgroups, and messages submitted by readers for unmoderated newsgroups are immediately propagated for everyone to see. Minimal editorial content filtering vs propagation speed form one crux of the Usenet community. One little cited defense of propagation is canceling a propagated message, but few Usenet users use this command and some news readers do not offer cancellation commands, in part because article storage expires in relatively short order anyway. Almost all unmoderated Usenet groups have become collections of spam.

Creation of moderated newsgroups often becomes a hot subject of controversy, raising issues regarding censorship and the desire of a subset of users to form an intentional community.

VIDEO CONFERENCING

·         Videoconferencing (VC) is the conduct of a videoconference (also known as a video conference or video teleconference) by a set of telecommunication technologies which allow two or more locations to communicate by simultaneous two-way video and audio transmissions. It has also been called 'visual collaboration' and is a type of groupware.

·         Videoconferencing differs from videophone calls in that it's designed to serve a conference or multiple locations rather than individuals. It is an intermediate form of video telephony, first used commercially in Germany during the late-1930s and later in the United States during the early 1970s as part of  Picture phone technology.

·         With the introduction of relatively low cost, high capacity broadband telecommunication services in the late 1990s, coupled with powerful computing processors and video compression techniques, videoconferencing has made significant inroads in business, education, medicine and media.

The tangible benefits for businesses using videoconferencing include lower travel costs and profits gained from offering videoconferencing as an aspect of customer service. The intangible benefits include the facilitation of group work among geographically distant teammates and a stronger sense of community among business contacts, both within and between companies.

 In terms of group work, users can chat, transfer files, share programs, send and receive graphic data, and operate computers from remote locations. On a more personal level, the face-to-face connection adds non-verbal communication to the exchange and allows participants to develop a stronger sense of familiarity with individuals they may never actually meet in the same place.

A videoconference can be thought of as a phone call with pictures - Microsoft refers to that aspect of its NetMeeting package as a "web phone" - and indications suggest that videoconferencing will some day become the primary mode of distance communication. The other components required for a videoconferencing system include:

·         Video input: video camera or webcam

·         Video output: computer monitor, television or projector

·         Audio input: microphones, CD/DVD player, cassette player, or any other source of PreAmp audio outlet.

·         Audio output: Usually loudspeakers associated with the display device or telephone

·         Data transfer: Analog or digital telephone network, LAN or Internet

·         Computer: A data processing unit that ties together the other components, does the compressing and decompressing, and initiates and maintains the data linkage via the network.

There are basically two kinds of videoconferencing systems:

1.     Dedicated systems have all required components packaged into a single piece of equipment, usually a console with a high quality remote controlled video camera. These cameras can be controlled at a distance to pan left and right, tilt up and down, and zoom. They became known as PTZ cameras. The console contains all electrical interfaces, the control computer, and the software or hardware-based codec. Omni directional microphones are connected to the console, as well as a TV monitor with loudspeakers and/or a video projector. There are several types of dedicated videoconferencing devices:

1.   Large group video conferencing are non-portable, large, more expensive devices used for large rooms and auditoriums.

2.   Small group video conferencing are non-portable or portable, smaller, less expensive devices used for small meeting rooms.

3.   Individual videoconferencing are usually portable devices, meant for single users, have fixed cameras, microphones and loudspeakers integrated into the console.

2.     Desktop systems are add-ons (hardware boards or software codec) to normal PCs and laptops, transforming them into videoconferencing devices. A range of different cameras and microphones can be used with the codec, which contains the necessary codec and transmission interfaces. Most of the desktops systems work with the H.323 standard. Videoconferences carried out via dispersed PCs are also known as e-meetings. These can also be nonstandard, Microsoft Lync, Skype for Business, Google Hangouts, or Yahoo Messenger or standards based, Cisco Jabber.

Conferencing layers

The components within a Conferencing System can be divided up into several different layers: User Interface, Conference Control, Control or Signal Plane, and Media Plane.

Videoconferencing User Interfaces (VUI) can be either graphical or voice responsive. Many in the industry have encountered both types of interfaces, and normally graphical interfaces are encountered on a computer. User interfaces for conferencing have a number of different uses; they can be used for scheduling, setup, and making a video call. Through the user interface the administrator is able to control the other three layers of the system.

Conference Control performs resource allocation, management and routing. This layer along with the User Interface creates meetings (scheduled or unscheduled) or adds and removes participants from a conference.

Control (Signalling) Plane contains the stacks that signal different endpoints to create a call and/or a conference. Signals can be, but aren’t limited to, H.323 and Session Initiation Protocol (SIP) Protocols. These signals control incoming and outgoing connections as well as session parameters.

The Media Plane controls the audio and video mixing and streaming. This layer manages Real-Time Transport Protocols, User Datagram Packets (UDP) and Real-Time Transport Control Protocol (RTCP). The RTP and UDP normally carry information such the payload type which is the type of codec, frame rate, video size and many others. RTCP on the other hand acts as a quality control Protocol for detecting errors during streaming.

Multipoint videoconferencing

Simultaneous videoconferencing among three or more remote points is possible by means of a Multipoint Control Unit (MCU). This is a bridge that interconnects calls from several sources (in a similar way to the audio conference call). All parties call the MCU, or the MCU can also call the parties which are going to participate, in sequence. There are MCUs which are pure software, and others which are a combination of hardware and software. An MCU is characterised according to the number of simultaneous calls it can handle, its ability to conduct transposing of data rates and protocols, and features such as Continuous Presence, in which multiple parties can be seen on-screen at once. MCUs can be stand-alone hardware devices, or they can be embedded into dedicated videoconferencing units.

The MCU consists of two logical components:

1.     A single multipoint controller (MC), and

2.     Multipoint Processors (MP), sometimes referred to as the mixer.

Videoconferencing modes

Videoconferencing systems use several common operating modes:

1.     Voice-Activated Switch (VAS);

2.     Continuous Presence.

In VAS mode, the MCU switches which endpoint can be seen by the other endpoints by the levels of one’s voice. If there are four people in a conference, the only one that will be seen in the conference is the site which is talking; the location with the loudest voice will be seen by the other participants.

Continuous Presence mode, displays multiple participants at the same time. The MP in this mode takes the streams from the different endpoints and puts them all together into a single video image. In this mode, the MCU normally sends the same type of images to all participants. Typically these types of images are called “layouts” and can vary depending on the number of participants in a conference.

Cloud-based video conferencing

Cloud-based video conferencing can be used without the hardware generally required by other video conferencing systems, and can be designed for use by larger international companies like Face book. Cloud-based systems can handle either 2D or 3D video broadcasting. Cloud-based systems can also implement mobile calls, and other forms of video calling. They can also come with a video recording function to archive past meetings.