Abstract
For over a decade, videoconferencing has been developing as a key component of distance learning in a variety of subject areas (Wang, 2006; MacLaughlin et. al., 2004; Kidd & Stamatakis, 2006; Sebrects et. al., 1995, Smyth, R., 2005). Although not a perfect replacement for faceto- face communication, videoconferencing can bring educators and students together although they may be separated by vast distances. Using videoconferencing technology, a lecturer in San Francisco can address students and colleagues in New York and Australia, students in Qatar and Pittsburgh can collaborate on a graduate research project and a doctoral candidate in Houston can defend his dissertation to a review board of faculty from a number of cities. Videoconferencing requires a substantial investment in equipment, expertise and support resources. Any institution considering such an investment must make a significant effort to evaluate the technical and usage requirements for a videoconferencing implementation to ensure the supportability and expandability of the system.
TopBackground
Videoconferencing is real-time two-way audio and video communication over a network. Envision a meeting between students in Pittsburgh and Qatar. The Pittsburgh students sit into a meeting room where, on the other side of the conference table, a large monitor displays the students in a similar meeting room in Qatar. In Qatar, the students see a similar monitor that displays the students in Pittsburgh. After some introductions, the students begin to discuss how they will collaborate on a research project.
As the students discuss their project, they are unaware of the technology that makes their conversation possible. As a student in Pittsburgh speaks, a camera captures the image of the conference room and a microphone captures the sound. Software then compresses the audio and video into packets that are transmitted over the internet to similar equipment in Qatar. Equipment in Qatar receives the packets and decompresses them and displays video on a monitor and audio through speakers. At the same time, the same equipment is transmitting audio and video from Qatar to Pittsburgh, so that the student speaking in Pittsburgh can see the reactions of the students in Qatar.
Videoconferencing has been available in one form or another for decades, originally through costly dedicated cable or satellite systems. However, the availability of ISDN (Integrated Services Digital Network) in the 1980s enabled videoconferencing over existing telephony systems and IP (Internet Protocol) solutions became available in the 1990s. As network infrastructure continues to be developed in response to larger consumers of bandwidth such as email, file-sharing and television broadcast, videoconferencing will benefit greatly from that growth. By 2015, video communication, including videoconferencing, will be the primary driver of network growth (Exabyte, 2008).
Users’ expectations have a significant impact on how the assess the usability of technology (Szajna & Scamell, 1993). As unified communications – the convergence of voice, video and message as well as other collaboration technologies – gains popularity and acceptance, users will expect high quality, seamlessly integrated audio and video communication as the norm (Passmore, 2008). As it develops as a key component of distance education and collaboration, users’ will increasingly perceive videoconferencing as they do email – that is, it is a utility that should simply work.
Key Terms in this Chapter
Bit Rate: Indicates the speed of a network connection in terms of the number of bits (a binary digit – either 1 or 0) that can be transmitted in a specified amount of time. For example, a bit rate of 128 kb/s indicates that 128 kilobits (128,000 bits) can be transmitted in one second.
Videoconferencing: A communication medium that provides two-way integrated audio and video transmissions simultaneously and in real time.
Codec: A device or program (or combination of the two) that codes and decodes data communication. Data is encoded at transmission and decoded when received.
MCU (Multipoint Control Unit): A bridge that interconnects videoconferencing data from several sources, similar to an audio conference call.
ISDN (Integrated Services Digital Network): A circuit-switched telephone network system, designed to allow digital transmission of voice and data over ordinary telephone copper wires.
Internet2: A consortium led by universities working in partnership with industry and government to develop and deploy advanced network applications and technologies. Internet2’s Abilene network (sometimes incorrectly called “Internet2”) provides a high-speed backbone for participating universities.
Packets: A formatted block of data transmitted over a network, allowing the network to deliver data more reliably and efficiently.
IP (Internet Protocol): A data-oriented protocol used for communicating data across a network, providing a service of global addressing for computers on the network.
Endpoint: A location with the equipment and network connections necessary to provide videoconferencing services.