Multimedia conferencing
The synchronous exchange of digitized multimedia information (e.g. video, audio, images) between conference participants at two or more separate sites Transferred images: Pictures of the participants Video clips, still pictures and other accompanying material in digitized form Screen or window content Transferred sound: Discussions between meeting participants Sound from accompanying material (sound or video clips) Group-system multimedia conferencing: Joins two groups of people meeting in physically separate rooms Personal multimedia conferencing: Joins individual users (desktops, phones) Two sites (point-to-point) or more (multi-point)
Multimedia Conferencing systems
System Type I: Picturephones Telephone sets enhanced by video display and small camera Available on the market already for significant time System Type II: Desktop Systems Desktop videoconferencing systems PC with small camera mounted above the monitor Picture phone on PC basis Optimal for application sharing Disadvantages: Usable only by a person a time Limited picture and sound quality
System Type III: Set-Top Systems Small box containing camera, microphone, speakers, codec, network
interface, To be put on top of TV set or monitor Simple, easy to use, targeted also to computer-illiterate users Disadvantage: Vendor lock-in: Upgrades are often difficult System Type IV: Rollabout Systems Movable, medium-sized unit, often a rolling cabinet, containing High-quality audio, video and telecommunication systems One or two large monitors Remotely controllable camera Optimal for small groups (three to six people) System Type V: Room Systems Room custom-equipped for conferencing requirements Possibly many cameras and monitors Furniture well integrated with conferencing equipment (cameras, monitors) High-quality sound system Electronic Whiteboard Touch-sensitive whiteboard To transmit life drawings over the network Technologies: Front projection, rear projection, LCD display Optical (infrared) tracking Collaborative software solutions with or without video conference
Applications Application: Distance Learning Lectures transmitted to remote students Training of staff in businesses Home-learning Integration of remote guest speakers
in meetings Application: Telemedicine Remote consultation of medical specialists Military health care for patients on remote bases Health care services for prison inmates Rapid emergency response Visiting nurses video-consulting with patients Allows reduction of physical visits Additional data possibly transmitted: Pictures: X-ray, tomography, Lab results Current vital data Application: Video Surveillance Remote surveillance is very similar to videoconferencing Use of similar equipment and/or software Examples: Security control of entrances, halls, Surveillance of public spaces (train stations etc) Traffic control Remote control of automatic bridges Bidirectional communication useful in some situations Types of Multi-Point Conferences Meet-Me Conference Conference is pre-arranged Time and address of bridge are known to participants Examples: Telephone conference services, Skype conference call Ad-Hoc Conference Conference starts as a point-to-point conversation
Grows to a multi-point conference when participants invite other people by calling their terminals Interactive-Broadcast Conference Asymmetric conference Master distributes media and signalling to many terminals Terminals have a much simpler back channel to the master Typical applications: tele-teaching, business TV
