What is Videoconferencing?

What equipment is needed for videoconferencing? | What technology does Women's Health Queensland Wide use for its videoconferencing program? | How do sites connect? | What happens while the videoconference is under way? | Do any problems arise?

Videoconferencing works by linking computers via a telephone line. Computers are equipped with cameras ad microphone facilities and the phone line is able to transmit both pictures and sound. Specialist software is installed on the computer and used for dialing a videoconference. Videoconference communication is two-way, just like ordinary telephone calls, except that participating sites can see, as well as hear, each other. Videoconferencing equipment allows switching between camera views and computer views, so that a speaker is able to show PowerPoint slides to other participants and then switch back to a face view.

What equipment is needed for videoconferencing?

Several types of videoconferencing installations are available. Normal desktop computers can be adapted as videoconference units by adding hardware and software, but larger sites or rooms can use self-contained systems with large TV-type screens for a larger audience. If necessary, a data projector can be connected to a computer to project a larger image for a larger audience.

What technology does Women's Health use for its videoconferencing program?

Women's Health has its own videoconference facility onsite and utilises the existing Queensland Telehealth network. Queensland Telehealth uses ISDN (Integrated System Digital Network) lines which transfer data at 128Kb per second.

How do sites connect?

Videoconferencing can connect two sites (called point-to-point) or many sites (called multi-point). When more than two sites take part in a videoconference a bridge is required.

What happens while the videoconference is under way?

The videoconference works on the basis of "voice activated switching" which means that the picture from the site currently speaking is transmitted to all sites. Whilst a speaker is talking, participating sites are asked to switch on their mute buttons, so that the videoconference view will not accidentally switch back to them if a noise occurs at their site.

For most of the time that a speaker is presenting, the PowerPoint presentation is on display to the viewing audiences and to the speaker, with the latter controlling the speed at which the slides are progressed. To maintain audience interest, each speaker is encouraged to identify natural breaks in the presentation, at which point the camera can be switched back to face view whilst the speaker summarises previous points or outlines forthcoming ones. During question time, participating sites are invited to ask questions and reminded that they will need to switch off their mute buttons to be heard. Sound interference can arise if sites do not switch the mute button off once they have asked the question. Each time a question is asked by someone at a distant site, the voice activated switching means that the relevant site becomes visible to all participants.

Do any problems arise?

Although the aim is that the videoconference will go smoothly, they are live events and designed for participation. They do not have the smooth and seamless quality of a TV broadcast. The informality and the opportunity for all viewers to participate is part of their appeal. It is our experience that technical hitches mostly relate to sound quality and, from time to time, participating sites do interject that they have sound problems. Sound can often be improved by a combination of local and remote sound adjustment. Sound quality can also be affected by:

• some sites failing to switch on the mute button
  
• poor positioning of the computer speakers in relation to the audience at the distant sites
  
• poor telephone lines (it is sometimes better for a remote site to hang up and then dial in again)
  
• poor microphone positioning
  

Other minor problems we have encountered include:

• lack of a picture from a participating site, for no obvious reason
  
• uncertainty about how many sites are involved in the videoconference at any one time; the sound signal for a site joining in is identical to the signal for a site dropping out, and this can cause confusion
  
• screen-saver timings on hardware causing sudden blackout
  

These are relatively minor issues and have not affected the overall quality of the experience.

For further information contact Kathryn Faulkner at Women’s Health on (07) 3839 9962 or KathyF@womhealth.org.au .

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Last Modified: December 4, 2007