Distance Learning
What is CIV?
Compressed Interactive Video or CIV is one of several technologies coming to the forefront of Distance Education. It has been touted as a cost effective, interactive means to educating students who lie outside an institution's traditional area, or who cannot attend the institution for other reasons. Before we can specifically address what CIV is, we need to look at Distance Education in general to see why the technology would need to be developed in the first place.
Distance Education (or Distance Learning)
Distance Education (or Distance Learning) is the practice of providing educational services to individuals who reside away from the educational institution. This encompasses everything from correspondence courses to educational radio and television to satellite broadcasts, but the one consistent aspect of Distance Education is that the distance between teacher and learner is bridged by technology. Each of the technologies that have been developed for use in distance education have been touted as the answer to the problem of reaching distant students. Yet each technology that has come along has also had its own drawbacks as well. The truth of the matter is that each technology has its strengths and weaknesses and they must be considered in regard to the audience that an educator wants to reach. For example, educational film was seen as a final answer to the delivery of audio/visual instruction to distant students (as well as those in traditional classrooms at one time). However, there is no way to ask a movie a question or for elaboration on a particular point. so, while very independent and self-directed learners may find educational films to be a satisfactory means of learning, other learners may require more feedback, and interpersonal communication. For these learners, an educational film would need to be supplemented by other activities or, more likely, educational films would themselves be a supplementary learning activity. For a more detailed understanding of Distance Education, see Michael Jeffries' Research in Distance Education, which begins with a very useful history, including Garrison and Shale's definition.
Compressed Interactive Video
In the case of CIV, the goal is to provide an affordable, effective and interactive transmission of classes over phone lines provided by telecommunications companies, in our own case: Southwestern Bell. This interactivity means that students and instructors can communicate audiovisually in real time.
The classes are photographed using video cameras which are connected to a computer called the MediaMax which has a very special card in it. This card, called a CODEC card (CODEC stands for Compression/Decompression), takes the video signal and condenses the image by removing unnecessary or redundant information so that can be transmitted efficiently over lines provided by the telecommunications carrier. The audio signal is handled in a similar fashion over the same lines.
In most cases, the line used in Arkansas is a T1 which consists of twenty-four 64 KBps lines linked together. The average system in Arkansas only uses a quarter of a T1 line (six 64 KBps lines) for a potential transmission bandwidth of 384 KBps. Some systems use an ISDN line (Integrated Services Digital Network ) which allows dial-up transmission to sites outside the state at an incremental bandwidth of 128 KBps. This bandwidth can be increased by using multiple lines. Recent innovations have allowed sites running over a standard T1 network to link up with sites running ISDN by connecting the ISDN site through the T1 network provider. The ISDN connection is made at the standard network connection of 384 KBps.
A new standard that is gaining ground is H.323, which uses the same data lines as an institution's Internet connection to connect with other sites. Since this means sharing the lines with Internet traffic, the systems that use this standard have to be able to prioritize a certain amount of bandwidth on the lines so that the conference connection is stable and uninterrupted. This issue is referred to as QoS (Quality of Service). The expectations in the videoconference community is that H.323 is the standard of the future and that systems will be migrating towards it. One key advantage of that standard is that sites should be able to dial directly to other sites without being scheduled through an MCU (Multipoint Control Unit) switch as is currently done on our state network.
Our site presently uses equipment manufactured by the VTEL telecommunications company, including the LC3200 computer and a Sony pan/titl/zoom remote controlled camera. The device used to control this camera, as well as change cameras and use other features of the system, is called a teleconferencing tablet. It consists of a stylus (a type of pen) controller and a tablet which comes with template sheets that allow the user to see which part of the tablet operates which device or feature in the system. The system also allows for document conferencing which means that documents can be exchanged both visually and (as computer files) physically. The system also has an electronic whiteboard that allows interactive written communication between two sites. We are presently using the H.221 videoconferencing standard. This standard is a software protocol that allows us to communicate with other sites on the state network.
For a glossary of terms used in compressed video please visit the site provided by Pacific Bell.
For questions/comments on this content, please contact Clint Brooks.
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