Behavioral and user needs for teleconferencing

Four forms of teleconferencing service are considered: audio only, audio plus freeze frame, teleseminar (consisting of one-way video and both-way audio), and full motion video conferencing, offering audio and video connexion on an equal basis from each location. For each service type, the authors seek to identify the nature of the constraints imposed, related to the dual--and occasionally opposing--needs of the user and of the company. Room, transmission, and network aspects are discussed in detail, and schemes for simultaneous multiple-location conferencing outlined. Practical examples from around the world are included to highlight the very real human factors challenges with which we are concerned. Full motion video conferencing is probably the most demanding service in terms of complexity of terminal equipment, coding equipment, and appropriate network structure. Currently such service is generally offered at transmission rates of 1.5 or 2 Mbits/s. Over the next few years there is expected be a move towards lower rates, e.g., 384 kbits/s, but domestic provision at 128 or 64 kbits/s is still considered much longer term.