You may think you understand video conferencing very well until someone who is familiar at all with it approaches you for a simple definition. If they ask, "What exactly is video conferencing, you could suddenly realize you are at a loss for words. The simplest definition of how video conferencing works is simply to allow communication through the integration of video, audio and peripherals, two or more people at once about any type of telecommunications lines. In other words, you are transmitting synchronized images and verbal communications between two or more places instead of them are in the same room. How video conferencing works one is more difficult little as the answer to explain the question, "What is video conferencing" Millions of people use every day, video conferences around the globe, but very few people know how the technical aspects of the process . work The main ingredients of a successful video conferencing are video cameras, microphones, appropriate computer software and computers and peripherals that integrate with the lines to relay the information. The analog data recorded by the microphones and cameras is divided into discrete shared units, translating it to ones and zeros. A codec codes the information into a digital signal that can then be transmitted at the other end to a codec that is retranslate these digital signals back into analog video images and audio sounds. The theory is the same, the transmission is in the early days of video conferencing, T1 changes ATM and ISDN lines, but used almost exclusively were really only practical for room-based videoconferencing systems. These dedicated lines were expensive and only large corporations tend to the facilities and have money to invest in this type of set-up. As the Internet became more a part of everyday life of all companies, it changed how video conferencing was conducted. The TCP / IP connections of the Internet are much cheaper and can produce large amounts of information to bear, including video packets for conferencing, relatively easily. For this reason, video conferences are more common in small businesses and in desktop packages that can be set with software for computer-to-computer networking. The compression of video transmission practical an issue that would convert the analog to digital transmission of results, the loss of clarity in an image. Analog signals are a continuous wave of amplitudes and frequencies showing shades and ranges of color, depth and brightness. If you digitally convert what is strictly 0 and 1, then you need a grid to values, intensities and saturations of different color values so that the image can be interpreted and reformed at the receiving end for development represented. This large amount of digital information requires huge bandwidth and means that the time it would take to transmit video images would not be practical for most applications. This is the compression of vital importance. When determining how video conferencing works, one of the key elements is the compression ratio. The higher the compression ratio, the faster the information to be transferred to himself. In many cases, however, this also means some loss of clarity or audio / video quality. For example, a compression ratio of 4:1 would be terribly be slow, but have a fantastic picture quality. But when it was transmitted, each at the other end would probably have left the room for a cup of coffee. Lossy compression discards unneeded or irrelevant sections of a signal, to transfer the essentials, speeding up the transmission time significantly but sometimes what a loss to quality. Compression can be either intra-frame or inter-frame for material that is repetitive or redundant, as the wall behind the conference participant. Since the wall remains static and never changes, the image is redundant and can be eliminated from transmissions to an extent with proper compression. Intra-frame compression assumes the redundancy in parts of a frame that are close together. Inter-frame compression assumes that there is redundancy over time (ie, as the wall). They can both achieve a relatively high degree of accuracy and reduces the bandwidth needed for transmission of signals. A newer version of compression / decompression is a technology developed by Cornell University SightSpeed. SightSpeed compresses only images considered essential and eliminating what to fill with 'filler', referring to the brain in the decompression at the other end. reached based on an artificial intelligence model, SightSpeed compression of about 90:1, compared to the typical 15:01 for video conferencing. Any video conferencing session you will compression of the transmitted signal. The key is to determine the balance between speed and image quality of video is right for your needs. Point to point video conferencing point-to-point video conferencing is just what it sounds like - a link between two different points on the planet, or two different video conferencing terminals. It could be between an office in New York City and a conference room in Munich. Point to point video conferencing can easily by one person on one end contacting the other end, as if such a standard phone call is initiated. No special precautions are taken, other than knowing that the participants be there. Multipoint conferencing is more complex multi-point conferencing is more complicated as it is to coordinate simultaneously to several different places. As you can not simultaneously be in direct contact with several places while they are all in contact with others, you need a source that bind them all together. In video conferencing, this is a multipoint bridge or multipoint conferencing unit (MCU) called. An MCU enables multi-location video conferencing by a "central processing center" for all places through which all information flows. The MCU receives all information from the various locations and then sends it to any location. In some cases the MCU is located on a specific PC, and in other cases it is located on a remote server (the most common structure, particularly for more powerful MCU networks). Audio is usually sent at the same time and in all locations with an MCU with no problem because of the relatively small bandwidth needed for transmission received. It is transmitted in the so-called "full duplex" mode, meaning everyone can talk and listen at the same time without cutting, when a person or another speaks. Video transmission can not transfer depends to a number of ways with an MCU on the quality of the software and the complexity of the system. Some common types of video transmission for video conferencing include: Continuous Presence video conferencing, up to four conference sites to see simultaneously on split screens. This is usually used when you see a small group or individuals in different locations and will primarily Nahaufnahmen.Universal Control video conferencing is controlled by the initiating conference site. The primary site determines who sees what is in all other Standorten.Voice Activated video conferencing is by far the most common type used today. The image with these systems shifts to the Web site that is currently activating the microphone so that you can always see who is speaking. However, if it is a good deal of background noise participants should mute their microphones when they do not talk to move the image to avoid unnecessary. Overcoming the language barrier Obviously communication via video conferencing can not if the two ends of the conference reached "speak the same language." That is, whatever is to be transmitted electronically be put together properly and heard and clearly seen at the other end . The Codec system (Coder-Decoder) is useless if both ends not with the same virtual language to interpret the signals. The International Telecommunication Union (ITU) developed a set of standards in 1996 called H.323 to specific guidelines for Video Conferencing standards and protocols outlining a way that would respect and support networks easier to achieve and maintain. Since then, many manufacturers and developers of video conferencing tools have adopted the H.323 guidelines as their own. Web conferencing solutions such as Click to Meet, Lotus Sametime, and WebEx offer enterprise solutions based on Internet video conferencing. These systems have protocols that can be downloaded and used anywhere at any location for subscribers through the Internet to be shared. These are becoming increasingly popular with companies that provide the comfort and convenience like. They are no more and more refined over time of doubt, compete with and perhaps surpassing the H.323 standards. There Overcoming firewall issues there, of course, overcome obstacles, if you have a look at how to take video conferencing works. Finally, you are sending large amounts of translated data either directly or through a gatekeeper system (MCU) that the conversion and transfer of information between multiple computers. Almost every company these days has a firewall system for ensuring safety and protect the system from potential viruses. The problem is, many firewalls also block the transmission of data for video conferencing. Recent innovations have largely seen these problems by designing firewall solutions, video conferencing signaling requests and make the information packets to the firewall or router without disabling the firewall protection for other road users bypass can be avoided. Even with this, but it may happen that packets are dropped because of heavy traffic on the system, so investing in a firewall system that can handle substantial traffic is essential to quality video conferencing performance. How video conferencing works will certainly over time, developed and improved in the coming years, but a basic understanding of what it is and how it works now will help you the best choice for you if you are ready to begin using video conference itself are. This article on the "How Video Conferencing Works" reprinted with permission. Copyright © 2004 Evaluseek Publishing.
