Raj Rai

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VIDEO CONFERENCING

VIDEO COMMUNICATION / VIDEO CONFERENCING

A

Video conference or video conference (also known as a video teleconference) is a set of interactive telecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions simultaneously. It has also been called 'visual collaboration' and is a type of groupware.

TECHNOLOGY

The core technology used in a videoconferencing system is digital compression of audio and video streams in real time. The hardware or software that performs compression is called codec (coder/decoder). Compression rates of up to 1:500 can be achieved. The resulting digital stream of 1s and 0s is subdivided into labelled packets, which are then transmitted through a digital network of some kind (usually ISDN or IP). The use of audio modems in the transmission line allow for the use of POTS, or the Plain Old Telephone System, in some low-speed applications, such as video telephony, because they convert the digital pulses to/from analogy waves in the audio spectrum range.
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: analogy or digital telephone network, LAN or Internet

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 videoconferencing is non-portable, large, more expensive devices used for large rooms and auditoriums.
   2. Small group videoconferencing is 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, usually) to normal PCs, transforming them into videoconferencing devices. A range of different cameras and microphones can be used with the board, 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.

ECHO CANCELLATION

A fundamental feature of professional videoconferencing systems is acoustic echo cancellation (AEC). Echo can be defined as the reflected source wave interference with new wave created by source. AEC is an algorithm which is able to detect when sounds or utterances render the audio input of the videoconferencing codec, which came from the audio output of the same system, after some time delay. If unchecked, this can lead to several problems including:

1. the remote party hearing their own voice coming back at them (usually significantly delayed)
2. strong reverberation, rendering the voice channel useless as it becomes hard to understand and
3. Howling created by feedback. Echo cancellation is a processor-intensive task that usually works over a narrow range of sound delays.

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 unit, or the MCU unit can also call the parties which are going to participate, in sequence. There are MCU bridges for IP and ISDN-based videoconferencing. 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 onscreen at once. MCUs can be stand-alone hardware devices, or they can be embedded into dedicated videoconferencing units.
Some systems are capable of multipoint conferencing with no MCU, stand-alone, embedded or otherwise. These use a standards-based H.323 technique known as "decentralized multipoint", where each station in a multipoint call exchanges video and audio directly with the other stations with no central "manager" or other bottleneck. The advantages of this technique are that the video and audio will generally be of higher quality because they don't have to be relayed through a central point. Also, users can make ad-hoc multipoint calls without any concern for the availability or control of an MCU. This added convenience and quality comes at the expense of some increased network bandwidth, because every station must transmit to every other station directly.

BENEFITS OF VIDEO CONFERENCING

• Video Conferencing Increases Productivity:

Video conferencing has the power to affect the way business and productivity gains can be derived. The ease to share any type of information has added dynamics to video communications. Decision making is faster, bringing products or services to market has become quicker, and all of this is helping companies to stay ahead of their competitors. Many companies now are using this technology for imparting training to their personals located at various geographical locations

• Video Conferencing Saves Money:

An additional benefit of using video conferencing is that companies are saving money due to reduced travel which was inevitable earlier. Today when companies are concerned about cost & time associated with travelling, video conferencing gives us the benefits in ways it was never have imagined.

• Video Conferencing For Students:

Students are now getting the advantage of video conferencing by taking classes at distant locations that would previously have been impossible. This way they can also accommodate their classes in their busy schedule. Now various institutions are also using this technology to organizing virtual classrooms to enhance the learning experience.

• Video Conferencing for Team Building:

Video conferencing has helped in stimulating better brainstorming, knowledge sharing and information gathering. This is helping the companies in taping the expertise of professionals distantly located. Also this has given rise to new concepts of online leadership.

• Video Conferencing for Medical Professionals:

In many countries medical professional are using this technology to regularly train their staff located in remote areas. Also this technology at times has proved helpful in detection of disease and medical consultation for far located patients.

• Improved Efficiency of Communication:

It is generally said that "a picture is worth a thousand words." Videoconferencing is the perfect example of this statement. A live video call can be much more effective in many situations. For example, if engineering staff needs to show one of its vendor a problem with a new component then visually seeing that part during a videoconference is far more effective and meaningful than trying to describe it over the phone or in literature.

• Improved & effective hiring:

Hiring processes at times can be very lengthy and costly, especially when interviewers have time constraint & are distantly located. Organizations with video conferencing systems in their offices can reduce expenses and time by bringing candidates into the nearest facility and allowing interviews to be conducted both in person and over video. Video interviews can also be recorded, enabling persons unable to be part of the live interview process to see and evaluate the candidate over video.

• Impact on Law:

Videoconferencing has allowed testimony to be used for individuals who are not able to attend the physical legal settings. In a military investigation in North Carolina, Afghan witnesses have testified using videoconferencing. In Hall County, Georgia, LifeSize video conferencing systems are used for initial court appearances. The systems link the jail and the court room, reducing the expenses and major security risks of transporting prisoners to the courtroom.

• Impact on media relations:

The concept of press videoconferencing was developed in October 2007 by the African Press Organization (APO).Press videoconferencing permits international press conferences via videoconferencing over the Internet. Journalists can participate on an international press conference from any location, without leaving their offices or countries. They need only be seated by a computer connected to the Internet in order to ask their questions to the speaker.

WIRELESS VIDEO CONFERENCE

Wireless video conference is still a very new on the block although wireless technology has changed the way we work for many people. Video conferencing services have been around for a while now and they give any business the edge in effective communication and collaboration. Wireless video conferencing extends that edge even further and is the best choice for one’s organization’s managed conferencing requirements. With some forms of wireless conferencing, management is less of a problem as participants can video conference as they walk around – this means that the idea of the meeting room may now be old hat, particularly with the mobile, battery charged, wireless conference system. Wireless video conferencing increases the efficiency of your business at a number of levels for example it is lot easier to make decisions when you can see somebody face to face.

HOW WIRELESS VIDEO CONFERENCING WORKS

Wireless video conferencing is one of the more advanced technical tools that are necessary to accomplishing greater efficiency in today’s working environment. A wireless conference can take place through web interface or a standalone decoding unit. These systems send high quality video and audio data to widespread locations through IP networks across the globe. Most wireless video conference systems are quite economical because they use the customer’s existing infrastructure which means no further investment and reduced costs.
These web conferencing systems, for example IVCI can be used for business meetings and for the transfer of information between experts in different locations .One of the reasons that the wireless video conference is still regarded as the new kid on the block is because there is a lack of ubiquitous high speed networking – video conferencing uses up an awful lot of bandwidth, and it takes quite a lot just to move a postage stamp sized image around a screen.