A major concern for distance learning about the technicality is connectivity and a transmission speed between a teaching site and students. Some distance learning technologies use analog transmissions and some apply digital ones. Traditional distance learning techniques (such as telephone and videotapes) are analog (represented by a continuous waveform). Newer technologies (such as computer and desktop videoconferences) are digital. The trend now is to move toward primarily digital systems in the distance education.
Various technologies, employed in the distance learning can be roughly divided into four categories: print, audio (voice), computer (data) and video. Each of these categories has several subdivisions. One of the subdivisions of the video category is satellite videoconferences.
Distance learning videoconferences can provide visual and audio realism of a face-to-face class. Full-motion video teleconferencing (referred to as videoconferencing) offers the "next best thing to being there." Two sets of equipment are needed for satellite systems. An uplink (a large satellite dish) transmits video and audio signals to the satellite. A downlink (a small dish antenna) receives and displays signals. A satellite transmission is one of the oldest, most established techniques for videoconferencing. In most cases, satellite videoconferences present one-way video and two-way audio.
Quite many universities, teaching at a distance, use satellite videoconferences as a cost-effective way to provide training to individuals, who live and work in areas that may limit their access to up-to-date information. It is more efficient to train individuals where they live than to transport them to another area; it also reduces travel time for trainers and permits them to deliver a consistent message simultaneously to thousands of professionals. Videoconferencing gives a possibility as well to reach students, who otherwise might be excluded from national training opportunities.
However satellite videoconferences are rather expensive, it would not be cost-effective for most school systems to use them, until they are in a position to market the classes over wide geographic areas. It is reasonable for a school to use the downlink to receive commercial courses that are delivered through satellite channels. One example of an educational system that makes use of satellite communication is EMG (Educational Management Group).
An ability to see and hear an instructor grants opportunities for behavior modeling, demonstrations and instructions of abstract concepts. Video technologies enable students and instructors to see facial expressions and a body language, adding personalities to communication. On average, more than ninety percent of those responding to surveys said that the content of the teleconferences successfully addressed critical issues, affecting their professional responsibilities. The survey also revealed that the panelists provided useful, understandable information and that they had used the ideas, presented during the teleconferences, to modify or implement programs in their communities.