INTERNET

VIDEOCONFERENCING

Introduction

Internet videoconferencing allows the user to exchange video, audio and data and allows the sharing of files via the Internet. This provides groups and individuals in different locations with a cost effective means to hold interactive meetings. AT&T pioneered videoconferencing in 1964 with the development of the PicturePhone. For almost three decades, AT&T remained the primary player. In the early 1990’s, new competitors such as Intel, PictureTel and VTEL began to develop personal videoconferencing systems. In 1990, the H.320 standards were approved. These standards allowed systems to interoperate. In 1995, the H.324 standard, which was designed for Plain Old Telephone Service (POTS) lines, was approved. POTS relied primarily on analog telephone lines. In 1996, the H.323 standard was approved and is becoming the standard of choice for Internet and Intranet videoconferencing.

There are three major types of videoconferencing systems, desktop PCs, roll-abouts and dedicated boardroom systems. Desktop systems are videoconferencing units which are installed as a separate application on your PC and are the primary vehicles for internet videoconferencing. There are also roll-abouts, which consist of one to two cameras and one to two video monitors, an audio speaker and a microphone housed in an easy to move cabinet. Dedicated board room systems are custom systems typically designed in a facility specifically arranged to hold videoconferences.

Technology Components
Basic internet videoconferencing systems consist of:
  • Monitor
  • Camera
  • Microphone
  • Speaker
  • Desktop PC
  • Sound and Videocards
  • Multimedia Equipment

Internet videoconferencing moves beyond basic point-to-point to tap into data and media resources that exist within the company’s intranet and on the Internet and utilizes true multi-media within a conference format. Internet videoconferencing allows a move toward multi-user application, control, and coordination of all users' activities. As PCs are integrated into videoconferencing, interfaces will become more Windows-like and more computing power will be available to use. Currently, the Pentium MMX can support a variety of video standards such as MPEG, H.324, and Microsoft NetMeeting. In addition, a PC allows for the replacement of the CODEC, a separate piece of hardware used for the compression of video. The computing power of current Pentium PCs can generally accomplish the data compression without the use of CODEC hardware.

Use of bandwidth is improving as more technology comes on-line, such as 100BaseT, fully segmented and switched hubs, tag switching, and ATM. Recent concerns regarding the effectiveness of packet switch networks delivering video and the effect on the quality of other data when running video, especially on local area networks (LANs), are starting to be addressed. One solution is RSVP, by Cisco Systems, which allows segmentation of the wire, prioritizing delivery of video. Another solution is frame relay which supports data sensitive applications such as SNA, packetized voice and packetized video. This is done via HDLC data transmission protocol so video adapts to the frame using Frame Relay Access Devices or FRADs. One more solution is the HOst Proximity Service (HOPS) which is a proposed internet-routing mechanism designed to improve performance by assuring that videoconferencing traffic is always directed to the nearest available server.

Advantages
Internet videoconferencing offers several advantages. First, there is the potential for substantial cost savings. These savings come in the form of travel time saved as well as the monetary costs of travel. For internet users who pay a flat monthly rate, there may also be per hour cost savings for internet videoconferences. Similarly, internet videoconferencing also saves time by allowing for non-verbal visual communication by enabling individuals to come together more quickly. In addition, internet videoconferencing allows for a computer-supported collaborative work environment. By being on a PC, users have access to computer applications, presentation systems, document sending and retrieval, and perihipal devices such as fax machines and scanners. Users can document objects and materials that can be captured as digital slides which can be exchanged, altered and stored on local drives.

Disadvantages
However, there are also disadvantages to internet videoconferencing. The first issue is bandwidth. The basic protocol for data exchange, TCP/IP, is not time sensitive with respect to the delivery of information. Since video and audio are time sensitive, programmers have to fix or bypass TCP/IP for videoconferencing and other multimedia. Some modifications to TCP/IP include UDP, RTP, and RSVP; however, no clear standard has emerged. Another major issue is inter-operability between PCs and the issue of degradation which arises using a packet-switch channel that is heavily loaded. As load increases and bandwidth available decreases, video performance can vary by compression type. In addition, for optimal video and audio quality, users must greatly increase the processing power of their PCs and the speed with which they connect to their ISP. Security issues also provide some concerns.

Major Vendors

The major vendors of internet videoconferencing packages are:

Present Issues and Future Projections

Once fully implemented, experts like Dan Labriola, from zdnet.com, expect the H.323 standard to "blend packet-switched LANs, intranets, and the Internet into a seamless videoconferencing environment." H.323 and similar standards will not only define the operations of videoconferencing workstations, but will also be able to route audio and video streams through the workstations. Intel developed the first H.323 videophone software package, the Internet Videophone in December 1996 and its technology has been incorporated into Microsoft’s NetMeeting. Most videophone vendors are currently working to either convert their products to H.323 or to add H.323 capabilities to their product offerings.

Internet videoconferencing is currently being used for medical systems via "tele-medicine." Tele-medicine involves the medical-system related applications of videoonferencing where doctors can quickly transfer x-rays, MRIs, and medical histories. Also, there are distance learning programs available where internet videoconferencing may be used to link students to speakers, labs, and exercises which may be taking place around the globe. Although internet videoconference hasn’t gained widespread acceptance in the business world, improvements in processing power, bandwidth management, and data compression will enable internet videoconferencing to be more readily employed. Future corporate uses include meetings, consultations, personnel interviews, sales presentations, training, and small conferences. Internet videoconferencing will never replace personal contact but does provide another tool capable of increasing productivity.

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Produced by Dan Campbell and Richard Hayes for Dr. Benn Konsynski

SOURCES

A Vision for Tomorrow

From Beginning to End; An End Users Guide to DTVC

New standards, lower costs, and ubiquitous Internet access are finally bringing videoconferencing out of the boardroom and into the living room

Enabling Technologies Desktop Video Conferencing

Videoconferencing over the Internet comes of age

A Brief Description of Videoconferencing

Desktop Videoconferencing