Video Conferencing
By Team Holt
I. History
Teleconferencing refers to the use of electronic communications that allows two or more people from different locations to have a conference. The term teleconferencing has been used to describe all three forms of electronic aided confere ncing-audio, video, and computer conferencing. Teleconferencing can be used throughout the problem solving process for exchanging information among the problem solvers who are located in different cities. This capability enables persons who otherwise woul d be left out for reasons of geography to contribute to problem solution. The biggest disadvantage of audio conferencing (telephone conference) is that they do not allow for face-to-face communication. Also, participants in one location cannot see graphs, charts, and pictures available in other locations. While the latter deficiency can be overcome by using a fax, it is a time-consuming, expensive and frequently a poor-quality process. One solution is video conferencing, where participants can see each ot her as well as the documents.
In a videoconference, participants in one location can see participants at another location or in several locations. Pictures of the participants can appear on a large screen or on a desktop computer. Videoconferencing has usually required special vide oconference rooms and videocameras, microphones, television monitors, and a computer equipped with a codec device that converts video images and analog sound waves into digital signals and compress them for transfer over communications channels. Another c odec on the receiving end reconverts the digital signals back into analog for display on the receiving monitor. These setups used to cost more than $50,000, a daunting price unless value can be demonstrated. However, with the availability of technology for using desktop PCs for video conferencing, 1995 had reduced the need for special conference rooms, although it is still expensive with the cost per seat for video conferencing at about $2,500 (in early 1995). Microcomputer bas ed desktop video conferencing systems where users can see each other and simultaneously work on the same document are even lower in cost. Here is an example of its cost today:
Academic Conference $87
Administrative Meeting $357
Regular Class $199
TEST $1
Test and Maintenance $142
Training workshop $49
Total conferences $835
The Surcharge assessed by NU-IT, NSHEC, and Tandberg Company to cover the cost of videoconference facilities' operation, maintenance, technical support, and troubleshooting:
Any Two NU-sites: $25.00/hr
One NU-Site to any one of the NSHEC sites: $35.00/hr
One NU-Site to any one other site: $58.00/hr
Multi-sites (three or more sites): $70/hr
Compare today’s cost ($835) with the $2,500 cost in 1995, you save 66.7%; Compare the $50,000 cost before year 1995, and it is 98.33% off! The advances of IT is making video conferencing cheaper, faster, and better. That’s the historical trend of every technological application.
Several interesting products are marketed by Picture Tel (PCS 100), Fujitsu (Desktop Conferencing), and Creative Technology (Share Vision PC3000). Some of these products use regular telephone lines and they can run either as standalone units or across the LAN.
Three basic video conferencing configurations are possible; depending on the equipment that is used.
Why videoconferencing? Interactive business communication‚videoconferencing - excels in multiple ways. It's almost like being there - the visual connection and interaction among participants enhances understanding and helps members feel connected to ea ch other. This lends itself to superior relationship building in a way that traditional mail, e-mail, telephone, or online chat systems cannot... and supports collaboration among traditionally isolated institutions. A Videoconferencing can improve retenti on and appeal with a variety of learning styles by including diverse media such as video or audio clips, graphics, animations and computer applications.
Video conferencing is growing in popularity because it saves travel time and cost. Legal firms might use videoconferencing to take depositions and to convene meetings between lawyers in different branch offices. For example, the firm of Howrey & Si mon with 300 lawyers in Los Angles has several expensive teleconferencing rooms that are busy almost constantly, linking them with their staff counterparts in Washington, DC. Designers and engineers use videoconferencing for remote collaboration. The cosm etics manufacturer Estee lauder is using desktop videoconferencing to enable staff in Manhattan and Melville, Long Island to view products under design along with the "talking heads" of meeting participants. Johnson Controls uses desktop videoconferencing for training and education partly because instructors can demonstrate an application to a distant user while simultaneously talking about it. Hospitals, universities, and even corporate researchers are using videoconferencing to fill in personnel experti se gaps. Video conferencing is even useful in supporting telecommunication, enabling home workers to meet with or collaborate with their counterparts working in the office or elsewhere.
Sources: http://www.at.nwu.edu/ctg/videoconf/rates.ssi
II. Technical Description
There are two basic categories of video conferencing systems – PC based systems and computer-free or stand alone systems. Many of the videoconferencing technical issues such as audio coding, video coding, communication, and document shar ing are the same for both systems. For purposes of this report, the following technical description will focus on PC-based videoconferencing systems.
PC Based Systems
The first requirement in PC-based videoconferencing is a connection between the computers. A wired connection (or wireless equivalent) must be provided to transport the audio, video, and other data. One of two likely connections is a local-area network (LAN) – a private data communications network bound to a limited geographical area. This network is often confined to a single office complex or department and provides the ability to interconnect and intercommunicate a group of computers and peripheral devices. An Ethernet is a common LAN connection that operates with a data rate of 10 Mbps (million bits per second), only sustaining half that rate in actual use. Since Ethernet LANs is usually shared, a single LAN may have several dozen-computer connecti ons. If the computers to be conferenced are on the same LAN, then the biggest problem is the level of congestion on the network, since the computers are sharing the 10 Mbps. When a computer tries to place information on an Ethernet LAN, it cannot be sure that no other computer is using the LAN. Subsequently, if there is a collision between two computers as they attempt access, they try again after waiting a random period of time. The other type of connection uses the existing telephone system and is calle d the basic rate ISDN (Integrated Services Digital Network), also known as BRI. An ISDN connection is much more predictable than a LAN connection. The ISDN line provides two B channels, each 64 Kbps (thousand bits per second), for transmission of video an d audio, and one-D channel of 16 Kbps for dialing and answering the call. An ISDN phone will usually use only one of the two available B-channels, but a videoconference will use both. Once the channel connections are established, the communication softwar e must manage the collection of the two channels to make the combined bandwidth available.
Once the hardware is in place, the audio and video subsystems need delivery service to send data across the wiring, with the data arriving at the intended destination. With LANs, assuming there is a physical path between computers that can be used for a conferencing connection, there must be ways for the computers to identify a logical path between the computers on which the audio/video subsystems can depend. The audio/video subsystems package up portions of data, mark them with an address, and give th e packets (packaged data) to the LAN software. It is up to the LAN software to see that the packets reach the destination address. A specific path may never be established between conferencing sites, and different packets may take different physical route s. The software in each system uses the delivery services without attention to the details of how packets get transported across the Internet. With BRI, a connection directly analogous to a telephone call is established for each B-channel when one compute r dials the other. The software that establishes the connections provides a delivery service for the audio/video subsystems. The connection software must recognize dialing states (on hook, dialing, ringing, busy, connecting) and react accordingly. This is done for both B-channels, usually one channel and then the other. On an internet, the different packets may take different paths, so some packets will take longer than others to get to the same destination. With BRI, data on one B-channel may get ahead o f data on the other. The delivery service can maintain records to guarantee that packets are delivered in sequence, depending on the guarantees expected by its "customers". Worse than arriving out of order, some packets will be lost entirely. Loss of pack ets on LANs and/or telephone circuits is inevitable, due to noise, congestion, etc. A delivery service is always expected to recognize a damaged packet, and will discard damaged packets. However, a delivery service that makes guarantees of delivery can ke ep the good data in the sequence. When packets seem to have been lost, such a delivery service will resend packets until they get through. The delivery services for videoconferencing are usually also responsible for multiplexing or combining the different kinds of data into a logical data stream. With the wiring and delivery services in place, other subsystems can then begin to send the data that make the conference real.
With the audio subsystem, the first requirements are for an input device, such as a microphone, and an out put device such as speakers or headphones. Inside the computer, there are three main audio subsystem functions: (1) conversion between analog rep resentations used by the input/output devices and digital representations used by the computer and delivery services, (2) echo cancellation (elimination of echoes caused by microphones capturing sounds produced by corresponding speakers), and (3) coding. Analog-to digital conversion consists of filtering (removal of undesired frequencies) followed by the actual conversion. Each filtered sample is passed on to the echo cancellation and coding functions. At the other end, the decoding process produces sampl es that are converted back to analog signals. The filtering, if done properly, results in better sounding analog signals. The analog-to-digital and digital-to-analog conversion must work both ways at the same time, both converting analog signals from the microphone to digital and converting digital signals to analog for the headphones or speakers. Converting both ways at the same time allows people to speak and listen at the same time and adjust their conversation accordingly.
Just as for the audio subsystem, the video subsystem requires an input device, such as a camera, and an output device which is usually the computer display. In the video coding process, excess visual detail is first filtered from the signal. The signal is then digitized. Next, the video is converted from the resolution and color space assumed by the camera to the YUV representation, which is the preferred coding of video for videoconferencing worldwide. The dropping of frames and otherwise filtering ex cess detail across successive frames is done at this point. Once the preceding steps are completed, the intensive computational work begins. The most ambitious and effective aspect is motion estimation – estimating which pixels in a frame are different fr om those in the previous frame. Rather than transmitting each entire frame, it is usually much more efficient to transmit only what has changed from frame to frame. If the differences are small, then no data are transmitted for this block, and the decodin g process will use the pixels from the previous frame for this block.
Even upon completion of the data reduction that takes place during the video coding process, 2 B-channels (a BRI connection) are not quite enough to handle full resolution and full motion. In the end, it is the responsibility of the video coding system to limit the coded video data to match the available bandwidth. To meet this responsibility, motion in the captured video is limited by coding fewer blocks. This may result in discrepancies such as "choppy" motion. After the encoding steps are completed, the data are multiplexed, and time stamped to enable the synchronization of audio and video at the decoding station. Here, priority is given to preserving time consistency of the audio data. Video data are matched to the audio data. If either the encodin g or decoding station gets behind on the video, it may drop video frames or take other special action to assist in maintaining synchronization. Finally, the decoding process is the inverse of the encoding process, but the steps are simpler computationally .
Video conferencing standards
The objective of videoconferencing is communication; however, the historical tendency of major vendors of videoconferencing systems was to develop systems with unique protocols that would not communicate with other vendor’s systems. Today, the majo r objective for the standard groups, vendors, and users is to make all of the standards talk with each other. This ensures that that the systems based on different technologies can interoperate. The International Telecommunications Union-Telecommunication s Standardization Sector (ITU-T) establishes recommendations for standard videoconferencing protocols.
H.320 is the main family of standards that impact ISDN. Of that family, H.261 defines two picture or resolution structures, the Common Intermediate Format (CIF) and the Quarter Common Intermediate Format (QCIF), that are compatible with all three world wide television display formats.
T.120 is the family of standards for desktop videoconferencing that governs document conferencing, whiteboarding, binary file transfer, and application sharing. This family of standards allows users to collaborate on documents running on completely dif ferent platforms. This standard also extends audio and video controls, providing the ability to remotely operate VCR’s.
The main family of videoconferencing recommendations for conventional LAN’s, such as the Ethernet, is H.323. These standards also cover Internet videoconferencing.
Another family of standards covers low-bit-rate videoconferencing between multimedia telephones over Plane Old Telephone Service (POTS). These telephones include stand-alone videophones, PC-based videophones, and TV-based videophones that resemble cabl e boxes with built-in cameras that sit on top of televisions. H.324 is critical in delivering desktop videoconferencing products to home and small office/home office (SOHO) market.
Other standards that indirectly impact desktop videoconferencing are the MPEG and JPEG standards for the coding of still images. MPEG stands for the Moving Picture Experts Group and JPEG stands for the Joint photographic Experts Group. Both are part of the International organization of Standards (ISO).
III. Video Conferencing Products
When discussing Video Conferencing technology it is important to also look at the products available. In today’s market there are many different options available to the video conferencing user from the small desktop packa ge all the way to the full room system. The most important factors when determining a video conferencing package are user needs, cost, interoperability, and keeping within the H-Standard of technology.
Setting up a video conferencing package can run the gamut from relatively inexpensive to extremely costly. Therefore it is important for the user to understand the requirements needed for his particular use and to research the available technology that fit his needs. The user must also look at the issue of interoperability and make sure his system is compatible with other systems it will be conferencing with. The formation of the H-Standard helped video conferencing technology become more standardized allowing for better and easier connectibility between users and is important when evaluating video conferencing products.
Currently there are numerous product and software packages available to the user. These packages and kits run from under $100 to upwards of $20,000 depending on the user’s needs. Before looking at the three levels of video conferencing products it is i mportant to first review the components of video conferencing to understand the necessities needed for the technology. The individual components are broken down into eight categories:
All eight of these categories are important components in supplying the user with a workable video conferencing system, and piecing together H-Standard products that work together is very important to the system’s reliability. These eight components ar e the bare minimum requirements for the small desktop individual to a large company utilizing video conferencing at a high level. Of course there are many additional add-on components and specialized software that can enhance the quality of a video confer encing application. For the purpose of this report will be to look at individual components, show how they are necessary to a video conferencing package, and finally look at a few of the products that are available on the market.
1. Individual Components
A. Camera:
The camera is very important to the overall product and can determine how well the video will be viewed by the receiving end. Once a user has determined what his needs are he can look at the many products available and utilize a camera that mee ts the user expectations. Relatively inexpensive Desktop PC Cameras are available on the market and as expected the more option a user desires the higher the cost. There are many extras available that can produce better video quality.
B. Microphone and Speakers:
A user must be discriminating when looking at microphones and speakers. If the video fails during a conference it is important the audio continue to be available to keep the functionality of the meeting in tact. Important features include location of microphone, echo control, and background noise suppression.
C. Codec
Codec (compressor/de-compressor) is very important to the overall quality of both the audio and video. In short Codec is responsible for taking the video and audio information and compressing it across the network to allow for near real time confer encing. The endpoints of the conference must be able to communicate with each another by utilizing the same language of interpretation. The H-Standard Codec can increase the likelihood of success. Codec can be utilized using both hardware and softw are components. More intense Codec applications are better utilized using Codec hardware while casual conferencing can be utilized through Codec software. The overall flow of a conference will be dependent on the Codec used.
D. User Interface:
The user interface becomes more important as the user’s requirements grow. For the casual user the most important factor in determining video conferencing success depends on how well the audio and video is sent and received. As the user demands mor e from his conferencing technology, user interface become a very important factor. Examples of user interface options include call logs, dial up menus, and a whole array of extra functions and benefits that can help make a video conferencing application m ore operable and successful.
E. Network Connection:
Simply stated the network connection is very important to the overall quality of a video conference. In the early days most conferences were held over dedicated networks using ISDN or dedicated T1 lines. With today’s user utilizing anything from a dial up connection to cable connections it is easy to see how network connection can become an impediment or an asset to the functionality of a videoconference. In short, the amount of bandwith a user is able to utilize will affect the success of a confer ence.
F. Video Display and Computer System:
There is not much explanation needed here. Obviously both of the components are givens in a desktop video conferencing situation. The higher quality monitor coupled with a faster efficient machine will help the overall success of a conference.
A. Software Packages and Video Conferencing Kits:
In the market today there are countless products and software packages available for video conferencing. The low end of products includes the use of a desktop camera, microphone, and speakers along with basic software to get the user started. The o wner of a PC can usually get started for under $100. There are great software packages that can be used by the casual user. These include Microsoft’s NetMeeting and Whitepine’s CU-SeeMe. These packages are easy to use and minimal equipment is needed to ru n a conference. To download NetMeeting or to purchase CU-SeeMe Pro click on the following links:
NetMeeting: http://www.microsoft.com/windows/netmeeting/
CU-SeeMe: http://www.wpine.com/Products/CU-SeeMe-Pro/index.html
To use these software packages basic kits can be purchased that will give the user the ability to get going pretty easily. Most kits feature full motion video camera (usually 10-20 frames per second), a microphone, conferencing software, all necessary
adapters and converters. The minimum requirements for such kits are Windows 95, 98 or NT 4.0,
Pentium 233 or higher with 32MB or more RAM, connection to the Internet, parallel port, computer and keyboard with PS/2 style connectors or computer and keyboard AT style connectors.
There are many products available for under $100. The following is a list of a few kits that can help the user get started relatively inexpensively:
Creative Labs WebCam Video Conferencing Kit: http://store.yahoo.com/pcsurplus/creatlabwebv.html
Sun USB Video Conferencing Kit:
http://store.yahoo.com/foxcomptech/noname1.html
Geneva PC Video Conferencing Package:
http://store.yahoo.com/pcsurplus/genvidconkit.html
CU-C-CU USB Video Conferencing Kit for notebook and laptop computers:
http://store.yahoo.com/usbvidconcam.html
Genius Internet Video Kit:
http://store.yahoo.com/electronics4less/geninvidkit.html
B. Hardware Assisted Video Conferencing Products:
For more specific business needs involving video conferencing there are more intensive hardware and software applications available. Certain products such as Intel ProShare, PictureTel LiveLAN, and VTEL Smart Station, are systems that involve more hardware assistance. Included in the hardware packages are usually an analog camera, video capture card, software, microphone, and a headset. While these systems are more advanced than the ones listed above they still tend to rely on NetMeeting to broadca st the information between endpoints. For more information on each of the products click on the appropriate link:
Intel Pro Share: http://www.intel.com/proshare/
PictureTel LiveLAN: http://www.fore.com/picturetel/
VTEL Smart Station: http://www.ktln.com/vtel/sstation.html
C. Room Systems:
For the most advanced products needed in business use there are room systems. A room system is an integrated hardware based product that includes a PC, capture card, advanced video camera, video display monitors, top of the line microphones, wirele ss keyboards, and software. These systems can cost between $5,000 and $20,000 depending on the needs of the user. These products are typically stand-alone configurations utilized solely for the purpose of video conferencing. Intel, VCON, PictureTel and VT EL are leaders in the room video conferencing systems. For more information on the room systems click on the following links:
Intel TeamStation: http://www.intel/proshare/conferencing/portal/teamdata.htm
VCON QuickConnect: http://www.vcon.com
PictureTel Concord 4500: http://www.picturetel.com/products/default.htm
VTEL Enterprise System: http://www.vtel.com/products/esa/default.htm
Whether the user needs a small desktop application or a large full room system, it is clear that there are plenty of products available to suit his needs. As long as the user can understand the requirements needed and is willing to take the time to res earch the available products video conferencing success can be easily obtained.
IV. User Experience of Video Conferencing
Video conferencing allows users to essentially have face-to-face meetings without requiring one or more sets of participants to travel. This reduces the time and expense required for travel. Travel expenses are large budgets of most companies, and typically the time spent in travelling cannot be usefully employed. In addition, travel causes a strain on the family life of the frequent traveler. Videoconferences are particularly useful for regular meetings in which routine matters and non-controversi al issues are discussed.
Manufacturing companies can use video conferencing to allow remote Engineers to "look at" and quickly resolve issues with product manufacture. Many companies have installed video conferencing equipment on manufacturing floors, allowing Engineers at remote sites to diagnose and resolve issues with their supplied components, without having to come on-site.
Issue number 99/02 of the magazine Videoconferencing Insight lists several examples of using video conferencing in unlikely locations or circumstances. These include:
The article, dated 2/2/98, reports that "A live demonstration of videoconferencing between a group of participants flying two miles above the Earth, and another group on the ground, has taken place in Italy. PictureTel collaborated with the German Aerospace Center (DLR), to enable the demonstration to take place.
The success of the trial will have a significant future on the impact of multimedia in aviation, eventually enabling aircraft manufactures to meet the demand of airlines for on-board multimedia services to improve safety, security and service."
The same issue of Videoconferencing Insight lists how NASA equipped the space shuttle Columbia with videoconferencing equipment, allowing "astronauts and NASA personnel to communicate visually. … The two-way communication allowed NASA physicists an d scientists on the ground to demonstrate experiments to the astronauts, and follow the results live. The astronauts were able to speak to their families during their long missions."
The article, dated 5/31/99, provides details on the world’s first telemedicine clinic established on Mount Everest, composed of 15 scientists, hikers and medical experts. "Each morning, doctors performing rounds at the base camp in Nepal, connected live, via the remote video camera and two 64kbps satellite telephones, with locations across the United States."
The world is on the verge of a teleconferencing explosion. The recent year have seen a variety of video and audio teleconferencing hardware and software solutions being used. CU-See-Me (webmasters may begin to integrate the user of CUSeeMe into Web sites. CUSeeMe, a teleconferencing program originally developed at Corne ll, allows users to see and hear each other by way of a video camera by converting the data into an Internet-compatible format), MBone, VDOlive, and others have provided users the ability to see and talk with one another. The results have received mix ed reviews depending upon the hardware used, the speed of the network or modem, and other factors.
We are seeing a convergence of issues because of the standards initiated by the International Teleconferencing Union (http://www.itu.int/). The H. 320 standard has been implemented for a long time now. New standards have been adopted by the ITU, namely H. 323 and H. 324. Simply put, H. 323 is the teleconferencing standard that will allow video teleconferencing over networks. H. 324 refers to the standard for video through "plain, old" telephone services. All of these standards can, and will, allow an end user to use any of these three standards to hold a teleconference with any other. The cost barrier is breaking down, with the H. 323 desktop system selling for below $3,500, as compared to the older, $60,000 conference-room systems.
The H. 324 systems are even less expensive, with prices hovering around $400. Some software is already available to the masses: NetMeeting 2.0 is free from Microsoft and is H. 323 compliant, with CU-See-Me 3.0 available for less than $7 0 coming in a close second. Just plug in your camera, hook up your microphone, and bingo! You're now H .3XX-compliant.
Where do these advances take us? Well, it leads to affordable video teleconferencing for many of us. Soon, coming to your desktop, there will be face-to-face student counseling, advising, and enrollment. Guest lecturers can be brought i nto lecture halls via the Internet, with two-way interaction. And, of course, video teleconferencing means the end to driving to remote campuses or even across campus. There are also distance-education possibilities.
All of this will come through your computer, whether it's in your classroom, dorm room, or at home. While this may seem fanciful to some people, it is quite possible. The challenges to be met on campus include the structure of the netwo rk, the quality of service it can provide, and the guaranteed bandwidth of the network. Resolving these issues will mean full-motion, computer -projected, full-screen video in the classroom.
Source: http://www.colorado.edu/ITS/Digit/julyaug97/teleconf.html
5. Future Advantages of Advanced Teleconferencing Equipment
Source: http://www.ctem.uwstout.edu/cet/hartz/web/TS1/Group_research/future/page.html
With the increasing availability of audio and video equipment on workstations, and with much faster networks being installed, we expect teleconferencing applications to become an important component of many future social and business in teractions.
V. Strengths and Weaknesses of Video Conferencing
Video conferencing has substantially altered the communication topography of businesses, distance education programs, and separated families and friends. Communication, communication, communication. The most obvious and poignant strength of video c onferencing is its ability to breakdown many traditional communication barriers. From a business perspective, companies find that application sharing and file transferring are also consequential advantages of utilizing video conferencing. The formation of strategic partnerships among manufacturers of video conferencing equipment and applications assures interoperability in the future.
The breakdown of traditional barriers that inhibit face-to-face communication in business related, educational, or personal scenarios is the primary strength of video conferencing technology. Examples of these barriers include distance, money, and time . This technology voids distance between two or more parties by facilitating face-to-face meetings in real time using equipment such as cameras, microphones, speakers, and video screens and programs that host the conference via networks. The money and tim e traditionally required by one or more parties to travel to a single location for face-to-face meetings are dramatically reduced. This is especially important for corporations because face-to-face interaction provides a greater sense of trust between par ties involved in b-b proceedings. Furthermore, face-to-face communication is an improvement over the use of email because it removes the possibility of misunderstandings through text. Voice inflection and gestures aid in the overall presentation of an ide a or thought. Interestingly, miles are not the only thing that form distance between two parties who need to communicate. Restricted areas such as clean rooms, nuclear facilities, and operating rooms utilize video conferencing to communicate with expert s cientists and doctors outside who can offer advice or help to those inside. Some programs allow users of video conferencing also save a huge amount of money by eliminating large long-distance phone bills. Some further examples show the benefits of video c onferencing to individuals outside the business community. Through distance learning programs, video conferencing has enabled disabled students to learn from home while interacting in a traditional classroom setting. Finally, families and friends are able to see and hear one another when distance or other obstacles separate them with this technology.
Video conferencing has also established a strong application sharing and file transferring option. Business associates across the globe can simultaneously work on Windows documents or other applications in real time. This saves time and money of sendin g it back and forth during a revision period as compared to the same process using email, mail, or fax.
The recent evolution and building of strategic partnerships among manufacturers of video conferencing related equipment and solutions has helped to further strengthen this technology. The alignment of firms and their technology yields higher interopera bility among all equipment and applications. This is extremely helpful in b-b relationships. In other words, cross-organizational meetings are possible via video conferencing regardless of the specific brand or model of equipment used by each firm because standards are followed across companies. These partnerships act as incentive for the firms to follow the standards because they will likely realize increased profits. An example of one of these recent pairings is that of Intel and Picture Tel. These two firms have been working together to combine respective strengths of PC technology innovation and visual collaboration to produce the best communications solutions while setting standards for future developments. Intel and Picture Tel joined together to ac celerate the growth of video conferencing by producing solutions for customers that will enhance the overall experience while following the standards that will increase interoperability.
To view related articles visit: http://www.intel.com/pressroom/archive/releases
The strengths of video conferencing translate into many positive benefits for the users of this technology. It is evident from a business perspective that companies save tremendous time and money after the initial investment is made to buy and make the equipment operational.
In contrast, video conferencing is a relatively new technology and is still in its initial stages of discovery and exploration. Weaknesses that the International Telecommunications Union (ITU), individuals, and manufacturers are still working to improv e are lack of sufficient bandwidth, loss of eye to eye interactions, and uncertainty of standards. Finally, some individual weaknesses result from the type of system users elect to employ: desktop systems versus room systems.
The lack of sufficient bandwidth can cause video and audio to be latent, jittery, or even lost completely. Video conferencing audio and video is put into data packets and digitally sent over networks. When these packets reach the end user, they are unw rapped and reassembled there. However, network congestion or sharing of insufficient bandwidth among many users causes the data to arrive late, out of order, or not at all. The resulting effects can be blank pieces within the video window, disruptions in audio, jittery picture, and/or talking over one another due to excessive delays. As bandwidth continues to increase, these problems will no longer exist.
Some businessmen and women are resistant to video conferencing technology because they like the traditional eye to eye and a handshake rule. These people would prefer to be in the same room when possibly making multi-trillion dollar deals that will aff ect the status of their company, and therefore, the status of their job. In some cases, video conferencing simply can not substitute for an actual face to face meeting.
Because video conferencing is still in its early stages of exploration, there is a danger of setting the wrong standards to govern all aspects of it. While strategic company partnerships, as well as, the ITU are working to establish a precedent, there is still a threat of over-specification or under-specification in this relatively early period of development. Over-specification forces manufacturers to produce expensive, detailed products at a higher cost to the consumer. Under-specification leaves roo m for interpretation by each vendor, and thus, lack of interoperability. The current standard, H.323, is somewhat under-specified. For example, the H.323 recommendation assumes the data network has no quality of service (QoS). This means there is no guara ntee that the delivery of data will occur promptly and in real time. Users will turn away from the technology if there is no guarantee of satisfaction. The standards set now in the beginning stages establish the precedent to be followed in the future. It is essential, therefore, that the right combination of specifications is achieved to allow the technology to survive and thrive for an extended period of time.
Here are further weaknesses based on the differences between utilization of room systems versus desktop systems. In room system based conferencing, users need dedicated high-end equipment on both ends. This leads to high initial set up costs for firms. Desktop systems are more convenient and cheaper, however, users deal with small screen size, and cameras that cannot zoom or pan and/or have small fields of view.
The relatively long time that video conferencing has been around has allowed adequate time to formalize the video conferencing procedures, thus providing a better experience for the user. Some relatively simple "common sense" methods to employ incl ude:
The administrator setting up the conference should ensure that all required equipment is in good working order. Video and audio signals should be received simultaneously, so that users are not irritated by one signal not being synchronized with the other. The signal quality should be reasonably good to allow a reasonable person to follow the conference proceedings. Poor audio or video quality would distract the user.
If the video conference is to be enhanced with a slide presentation at each of the local sites, it is advisable to have some mechanism by which the presenter can change the slides at all sites simultaneously, to eliminate a site being not synchroni zed with the presenter.
All users should be easily able to view the monitor(s), to increase their involvement in the conference. Monitors should be angled such that the greatest number of users can easily view them. If necessary, monitors may be suspended from the ceiling , or raised on stands to allow all participants to view them easily. Lights in the room should be adjusted so that glare on the monitors is reduced, but at the same time, provide adequate lighting for users to take notes or follow-up on printed materials. The Online Group at TVOntario suggests that there should be an adequate number of monitors such that there is no more than 1 viewer per 1" of diagonal inch of monitor screen; thus a 21" monitor should have no more than 21 viewers.
In videoconference rooms, one must ensure that an adequate number of microphones are installed in the room, to allow easy two-way audio communication between sites. If an inadequate number of microphones were available, only a limited number of par ticipants would make themselves be adequately heard when speaking.
The video conference room must be equipped with an adequate amount of cameras to make the videoconference experience a pleasant one. As an example, if it is necessary to transmit live images of not just the participants, but also still images of do cuments, collateral, or equipment, it is necessary to have a fixed camera with a narrow range under which the user can put the document, etc. and transmit a good-quality still image of it. Holding the document in front of the camera that is focused on the audience is a poor workaround, since this camera would have a wide-angle lens and would not be suited to the task. If two cameras are used to transmit images, it is necessary to have the ability to switch between both inputs, or allow a picture-in-window type capability to ensure that all participants can see both the transmitted image of the documents, as well as the speaker, thus gaining as much as though they had been attending the meeting in person.
The camera used to capture the participants’ image should be appropriately focused and should have an adequately sized wide-angle lens to allow all participants’ images in the room to be captured. Wherever possible, the camera should be of as good a qu ality as possible to allow a reasonable image to be transmitted. Enhancing a remote participant’s experience of the videoconference is the ability to clearly see a remote presenter, and his/her facial, lip or hand movements.
If the technology used for transmission of high-bandwidth applications is not up to snuff (it is not today, unless it is made hugely expensive), many video conferences suffer from poor video images, which can include jerky motion, partial views, et c., which increase viewer distraction and frustration. In many conferences, it is not really necessary to view a real-time image of the transmitting site at all. Is this is the case, limiting the use of real-time images greatly reduces the bandwidth requi red for the conference. Conferences in which images are frozen and displayed on monitors can actually be quite effective, and are no less useful than face-to-face meetings in which a presenter uses a set of slides to add to his/her presentation. Using the video bandwidth no more than necessary thus allows for a very effective conference.
Participants in videoconferences should use visual materials where possible. Documents can be emailed earlier (prior to the conference) or transmitted via the "document" camera. When transmitted via camera, the documents should be in bold, large si mple font (one that does not have extremely thick or thin lines). The documents will be more easily seen if they are on paper with a white background, not on transparencies. Colors should be judiciously used; those colors that stand out too much or blend into each other should be avoided.
Participants in a videoconference should avoid wearing white colors, large jewelry that reflects light, or clothing with overly detailed patterns. Such images are difficult to see at the remote locations, and may distract users at those remote loca tions.
Participants in a videoconference should observe the same etiquette and set of rules when in a face-to-face conference. In addition, users should not shuffle papers, tap pencils, or create other noise close to microphones. They should speak and act naturally, but recognize that there is a transmission delay and should pause longer, to allow other participants to interject or comment. Movement should be kept to a minimum, particularly if the video transmission results in jerky movements.
VI. Future Prospects
Future uses include an increased reliance on telecommuting, and the use of cellular videophones. Telecommuting allows students and employees to learn or work at a distance, either in telecommuting sites or at home. The main purpose is to reduce commute time, the use of gas, and air pollution. There are many studies on telecommuting; it seems to increase productivity and people enjoy having flexible schedules and more time.
Another objective is the development of cellular videophones. We have already seen some in the last technology shows. The communications technology from Star Trek and AT&T commercials (Have you ever tucked your baby in from halfway around the world ? Have you ever attended a board meeting barefoot? You will...) gives some idea of the future of teleconferencing.
The increasing use of teleconferencing for distance education, cutbacks and increasing specialization in higher education, and the inability of universities to respond quickly to demands for new courses, may eventually lead to something like a hyper-un iversity, where instead of attending one college, students will be able to browse through courses from different universities networked across the country.
Examples
In distance education, many colleges and universities around the country are using teleconferencing to reach students that otherwise would not be able to participate in the learning process. Through the use of proper equipment, the instructor is ab le to teach a class in which some students participate from different locations. States that are vast in size or have remote towns have developed this technology as an option to educate people that otherwise would not be able to go to college. In West Vir ginia, a unique program designed to rectify problems with poorly-educated special education teachers by certifying teachers with full-time jobs who already hold bachelor's degrees uses teleconferencing in combination with flexible class schedules and trav eling instructors. In California, the UC Universities use teleconferences regularly to teach their courses and to exchange information and communicate.
Other educational uses include on-line collaborative learning, which has been tried at two universities in Canada, and KIDLINK, a teleconferencing system that allows children around the world to communicate with each other using the Internet.
In the private sector, Hewlett Packard and AT and T have successfully used teleconferencing to train their staff, drastically cutting travel costs.
Cost
It is difficult to determine the exact cost of teleconferencing since there are so many different options. Audio-only teleconferencing can be done fairly cheaply. AT&T's rates include a fee of $4.00/person, with a charge of $.53 per person per minute. For video teleconferencing, the options include buying the equipment or leasing it. Once the equipment has been purchased, the actual teleconference is fairly cheap. Set-up costs for the main site might range from $10,000 to $200,000, with additio nal costs for each remote location. There is also the option of renting facilities. Including all the equipment and the engineer's time, these costs would vary from $100/hour to $500/hour. Even though costs appear to be high, costs of equipment and tutor time in a telecommunications environment are often lower than the costs of providing the space, travel and lodging for learning in a traditional environment.
ORCHESTRATOR: Built to Military Standard Specifications
In a scale unmatched by other systems, the ORCHESTRATOR provides from 8 to 160 ports with full voice/video/data conferencing. ORCHESTRATOR protocol modules, integrated with CONTEX architecture, deliver full-range audio conferencing with multimedia capabilities that meet ITU H.320 and T.120 standards. ORCHESTRATOR matches its high capacity with high speed, currently transmitting at 384kbps per port. The Compunetix patented space division switching architecture allows for dynamic port all ocation and an easy option to migrate from audio to video.
ORCHESTRATOR: Features That Mean Flexibility
With Windows-based software, the ORCHESTRATOR brings multimedia conferencing to the desktop. It turns a simple PC into a full multimedia control center. Supporting up to fifteen operator consoles, the ORCHESTRATOR offers an abundant sui te of features. Features are available for attended and unattended conferences, along with music and video on hold, and incoming call queue management.
Taking Teleconferencing into the Future
Today, large capacity conferencing systems must be fast, reliable, secure, and rich in features. The ORCHESTRATOR uses advanced patented technology to provide high speed, high capacity, and reliable multimedia conferencing. The ORCHESTR ATOR is available in standard configurations or as an upgrade to the Compunetix CONTEX audio teleconferencing systems. The ORCHESTRATOR delivers full-spectrum multimedia capabilities to any organization offering multimedia to its staff or teleconferencing customers.
Features of the ORCHESTRATOR Models 80 and 160:
Large Scale Cost Effective Solution
One product supports audio, video, and data simultaneously in any one conference.
Technology with Longevity
The ORCHESTRATOR features a software-based protocol implementation coupled with modular hardware architecture.
Maximum Operator Efficiency
The Windows-based operator interface, which is easy to learn and use, permits:
Video Modes:
Ensemble™ - continuous presence available in Mixed, Dual, and Quadrature modes with voice activated sites
http://www.changsung.co.kr/orchestrator.html
Martin Greenwald, Sandy Merola, Larry Price, Bill Wing for the ESnet Steering Committee
February 14, 1998
Background
The ESnet Steering Committee formed an Applications Requirements Working Group to help ensure that future network requirements of the ESnet community are identified. In particular, this working group focused on applications whose demands, in the five-y ear time frame, are expected to exceed current network services. We acknowledge and appreciate the input from members of the ESnet Coordinating Committee, MICS-funded network research principal investigators, and principal investigators throughout the DOE community, including participants in the recent DOE Large Scale Networking Workshop. As we work together to realize the benefit of network advancements, we expect that the ESSC, the ESnet implementation team, and the MICS program office will supplement this document with experience acquired from DOE2000, the Network Challenged Applications program, and other contacts within the DOE research comm unity.
Teleconferencing and Videoconferencing
The ESnet community has embraced and benefited greatly from the present availability of conference-room-based videoconferencing. Useful as it is, teleconferencing is in its infancy and needs major improvements. Advances are needed initially in ease of use, the incorporation of multimedia interactions, in the shared creation and editing of documents, and in the integration with data collection and analysis environments. The expansion of usage has increased the need for service directories, and the m ultiplicity of participants in any single session has created the need for floor control capabilities. Both are needed to ensure the future viability of teleconferencing. Additionally, as tools become easier to use and more integrated into the networked e nvironment, general planning and coordination services will be needed.
Demands from the increased utilization of workstation-based videoconferencing could be enormous. The high-energy and nuclear physics communities suggest that their videoconference use in the near future might be as demanding on the network as their cur rent data requirements-perhaps within two years as the B factories become operational in the U.S. and Japan and the Tevatron Run 2 begins at Fermilab. In the five years after that, high-energy physics will need an extensive evolution of the present confer encing system to permit effective work with gigantic data sets by extremely distributed groups of collaborators. The new capabilities required will almost certainly require evolution of relevant network protocols as well as the software at the end nodes. The ESnet community will need to have the expanded conferencing ability integrated closely with Remote Experimental Operations, placing even more demands on the detailed operation of the network.
Conference rooms throughout the ESnet community are already fully booked with apparent unsatisfied demand. The lack of both universal interoperability and ease of use continue to pose a barrier to increased usage of this service. Commercial providers d o not seem motivated to resolve this hurdle. On a positive note, standards have been recently developed in this area, and low-cost commercial implementations have created the potential for significant increased use. ESnet will need to ensure timely and su pported advancements in this area.
ESnet collaborations can be expected to make heavy use of workstation-based videoconferencing. However, the existing service model is a barrier to widespread use as it only adequately supports small numbers of participants. In addition, there is a need for a complete, readily accessible directory of institutions and individuals who are accessible via this medium.
Sources: http://www.cebaf.gov/exp_prog/esnet/design/adtech/avdappl-final.html
Team member’s homepages:
Master Percy: http://www.geocities.com/percy_master
Dana Dingler: http://members.xoom.com/ddingler/aggie98.htm
Yaramy Trevino: http://www.geocities.com/yaramytrevino
Fabio Visentini: http://student-tourist.8m.com
Hong Yue: http://www.cs.uh.edu/~lji/hong.html
Walter Montague: http://www.geocities.com/waltmontag/walt.html