AGOCG logo
Graphics Multimedia VR Visualization Contents
Training Reports Workshops Briefings Index
This report is also available as an Acrobat file.
Back Next Contents

Distance capability

In three cases, videoconferencing facilities are only available on the local Ethernet. Of the remaining respondents, half have international capability (via ISDN or the Internet) and the other half are operating on a wide area network (WAN). For example, a WAN links the SuperJANET video pilot sites. In some cases the WAN is potentially world-wide via ‘protocol-converters’ at University College London.

On some sites there is variable distance capability available: e.g. a local analogue part of the network operating within the campus; an analogue part of the visual network with wide area capability; and a digital part of the network which is national (via SuperJANET) and international (via ISDN).

Limit to the number of individual parties in a call

Often there is no theoretical limit to the number of individual parties in a call. Indeed, respondents report being able, for example, to run 5-site meetings with 26 participants and to relay a meeting of 200 people to 13 other sites. Some sites find it wise to set a practical limit of 5-6 sites for a multisite conference (’discussion’), whereas there is no need to set a limit for a ‘broadcast’ conference (one to many). Most users report being able to accommodate between three and six participants at each end (except, of course, in a teaching context, in which case there might be 80- 100 in a lecture theatre).

CU-SeeMe allows the reflector administration to set an upper limit at their discretion, whereas the MBONE does not seem to have an effective limit (e.g. the number of participants reached the 200 mark during the last shuttle flight).

Frequency and duration of use

A third of respondents are making daily use of their videoconferencing facilities, with most others using it at least 1- 2 times per week. Equipment that is used for educational purposes seems to be utilised at least once per week, with two studios reporting that they are in use for 70% of the time and 12-25 hours per week during term-time respectively.

The length of a typical call (presentation/ conversation/ lecture) clearly varies according to its purpose. A short conversation could last for less than ten minutes, whereas presentations may last all day and participation in a conference is likely to last for several days. The majority of calls, however, seem to fall within the range 15 minutes to 4 hours.

Importance attributed to the video link

Most users described the video link itself as “very important” or “essential”, especially for fast communication. Its role is obviously greatest when giving presentations and teaching, and helps to give context to slides, etc. Visual contact is also very useful during discussions.

However, it was pointed out that the video may be very valuable but it is not as important as good audio ( although if the audio link is down, it is good to be able to see that there actually is someone sitting at the other end!). “Video aids understanding but without audio there is nothing to aid visually!” Greater importance was also given to the shared whiteboard than to the video link.

Associated facilities

Users were asked to give details of the associated facilities they use to accompany their videoconferencing. Examples are given below of some of the combinations of associated facilities in use. They are given in full, for interest. The letters in brackets are cross references to the example configurations given in Appendix 3.
Back Next Contents

Graphics     Multimedia      Virtual Environments      Visualisation      Contents