VIDEOCONFERENCE: HISTORY AND PRESENT.
Videoconference or video call is the bidirectional simultaneous communication of audio and video.
Which allows keeping meetings with people groups located in distant places among them.
In addition, telematic facilities or another type like graphic exchange, still images, file transmission from a computer and other devices, can be offered.
The technological core used in a videoconferencing system is the digital understanding of audio and video streams in real time.
Its implementation brings us important benefits, as collaborative work among geographically distant people and greater integration among some work groups.
This allows to keep meetings with people groups located in distant places among them.
And also allows graphic information, images, and files.
Audio and video transfer exchange, sharing the computer explorer, make presentations, etc.
Nowadays, technical limitations, such as:
- Poor sound
- Bad quality of images
- Poor reliability
- Complexity and cost
Have left behind giving place to high quality videoconferences with audio, video, files transfer and more than accessible cost to the most interested.
In other words, videoconference today offers an accessible solution to the communication required.
With systems that allows transmitting and receiving visual and sound information among different points or areas.
Avoiding expenses and waste of time which imply the physical transfer of the person.
These advantages make videoconferences the greatest growing segment in telecommunications area.
Those videoconference systems, generally, were composed for two close circuit system of television connected through coaxial cable or radio.
An example was the Postzentralamt Reich network (German mail office), created in Berlin and other cities since 1936 until 1940.
During the firsts manned specials fligts, the NASA used two radiofrequency links (UHF or VHF),
One in each direction. Also television channels usually used this type of videoconference to inform from different places.
Then, the mobile links to satellites by means of trucks specially equipped turn into something common.
This technique was so expensive and could not be used in applications like telemedicine, distant education or business meetings.
The attempt to use normal telephony networks to broadcast slow-scan video.
Like the first systems made by AT&T did not work, due to poor image quality and the lack of efficient video compression techniques.
They had a video broadcasting of 30 frames per second;
The images were black and white, for which they used a conventional telephone line.
It was not until the 1980s that digital telephony transmission networks became possible,
like DNIS, ensuring a minimum speed (generally 128 kilobits/s) for compressed video and audio broadcasting.
During this time, there were some investigations about other digital video and audio communication ways.
Some of these technologies, like “media space”, are not as used as videoconferencing today.
But they were an important area of research.
The firsts system dedicated began to appear in the market at the same time than DNIS networks expanded around the world.
One of the commercial first systems of videoconferencing sold to companies came from PictureTel Corp. that had an initial public offering in November 1984.
The videoconference systems in the 90’s evolved quickly from expensive property equipment,
Software and network requirements to a standard base technology available to general public at a reasonable cost.
Finally, in the 1990 decade, the videoconferencing based in IP (internet protocol)
Has made it possible, and they developed into more efficient video compression technologies.
Which allow videoconferences from a personal computer (PC).
In 1992, CU-SeeMe was developed in Cornell for Tim Dorcey.
1995, Intel and Microsoft worked together on an initial standardization of activities for VoIP communication systems.
The same year, the first public videoconference and emission between Africa and North America continents took place.
Linking a technology fair in San Francisco with Techno-Rave and Cyberdeli in Cape Town.
In the Olympic Games Opening Ceremony on winter in Nagano, Japan, Seiji Ozawa performed the Ode to the Joy of the Ninth Symphony of Beethoven simultaneously in the five continents in almost real time.
In the 2000 decade, video telephony got popular through free Internet services like Messenger or iChat,
Telecommunication programs online that promotes videoconferencing to practically all locations with Internet connection.
In May 2005, the first systems of high definition videoconference high, produced by LifeSize Communications,
Were exhibited at the Interop fair in Las Vegas, Nevada, being able to promote 30 frames per second to a 1280 x 720.6 screen resolution. Nowadays,
High definition resolution has not become a standard features yet,
Some months later the NETConference site web showed its Videoconferencing Online platform.
The first one in distributed services in the Cloud,
More similar to Web Conferences than video conferencing systems properly said,
Despite this platform exceeded expectations due to its advanced features and service quality which allow to offer some video quality.
High definition including FullHD, at the same time, it included an important feature that until then had not been taken into account,
The security at communications, the security offered greatly exceeded the previous ones,
A great step in security not only allowed encrypted connections, it also encrypted the communications themselves.
Allowing companies to be able to adopt efficient ways on communication security equipment.
In 2012, MashMeTV, would launch a new concept that would revolutionize videoconferencing: video-collaboration.
This new service would include videoconferencing as a core of multiple collaborative activities course,
Such as files share or the possibility of watching videos in a totally synchronized way while the videoconference stays online.
Nowadays, there is a growing demand from companies that have made the leap from videoconferencing to video-collaboration
Which has meant an important technological advance
With the implementation of WebRTC as a substitute for Flash technology.
The basic technology used in videoconferencing systems is the digital compression of audio and video in real time
That arrives by Link by a Circuit of Fiber Optic signal and simultaneously by satellite event signal by 2 Consoles.
The hardware or software which makes the compression is called “codec” (encoder or decoder).
Basically, there are two types of videoconferencing systems:
1. Dedicated videoconferencing systems:
They have all necessary components labeled on a computer, usually a console with a high quality video camera controlled remotely.
There are some types of dedicated videoconferencing devices:
- Videoconferences for big groups:
They are long devices, not portable, more expensive usually used in big rooms and auditoriums.
- Videoconferences for small groups:
Are not portable, they are smaller and less expensive, they are used in small meetings.·
- Individual videoconferences:
They are usually portable devices, destined to individual users.
They have fixed cameras, microphones and speakers integrated in the console.
2. Computer systems:
The computer systems are accessories –added-(usually hardware targets) to normal PCs’,
Transforming them in videoconferencing devices.
Which has the codec and interfaces of necessary broadcasting.
Most of computer systems works with standard H.323.
The videoconferences made through scattered computers are also known as e-meetings or web-conferences.
The vast majority of web conferencing solutions uses encryption protocol SSL of 128 bits for secure access to conferencing rooms.
And some of them at 256 bits. However, these levels are obsolete.
The big manufacturers, Polycom or Tandberg,
Offered an optional way by the implementation of security servers that offer encryption of up to 1024 bits,
Increasing significantly property total cost and the final price of solutions.
At the moment, only the NETConference Website platform is able to offer a level up to 1024 bits,
As well as to encrypt the communications themselves up to 4096 bits,
What becomes it the safest platform of communication and the only one to be able to be used by all those who are included in any of the levels of the Spanish Data Protection Act or LOPD.
Videoconferencing in education.
This technique makes inclusion of a new concept of the teaching concept of educational space,
It took place to new organization ways, methodologies and interactions.
The videoconferences used by teachers and students suppose benefits, for educational entities.Those benefits are:
- Cost savings: avoid displacements, travel expenses and pollution.
- Ideas exchange, knowledge and information.
- Increase in productivity and competitive advantage between users in this technology mean.
- An additional alternative for the best use of computing resources
- To meet academician in different geographic places
- To plan investigation and cooperation strategies
Which are the technical means, the subjects, the length,
The participants on the experience which includes a previous period of selection of subjects and joining study of methodology.
As well as the most appropriate pedagogical material to accompany the class (notes, videos…).
It is previously said that this help us to think and multiply the several benefits of videoconferencing in the education.
In addition, this will mean innovative teachers.
Changes in their methodologies and the need to be a carrier of technological competence.
It is the most popular tool, with an excellent quality of audio and video, It is available for all operative system, from Windows to Mac, Android, Kindle, etc
It allows a free way of making group videoconferencing of up to 12 users.
With a high speed and broadcasting quality based on powerful Google servers.
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