Learning without Boundary
Application of Satellite Communication System on Distance Education

By Hsin-Ho Tsao, Taiwan

Nowadays, the concept of global village has been developed over the world due to the development of communication technology. The information boundaries between areas and regions are gradually eliminated. People are able to have long-distance communication and information exchange, such as searching information via the Internet and making long distance calls that include images. The convenience of communication brought by the technology is applied to education as well.

Distance education is an innovation that allows educational content to be transmitted from area to area and provides students in rural areas an opportunity to get education as well. Originally, the format for electronic distance education was to broadcast information through radio or television stations; more recently, microwave radio technology has been applied within a small region. Students received lectures from distant teachers, but were not able to interact with them. The rapid development of the Internet provides another option for the implementation of distance education.

Due to the need for high speed and high quality educational messages, communication satellites are often used more for efficient transmission. This paper discusses how satellites meet the needs of distance education, the satellite systems that are used in distance education, and some concerns about applying satellites to distance education.

Development of Distance Education

The main purpose of distance education is to provide people greater access to education without the limitations of distance and boundaries. The potential benefits of distance education are user driven experience,[1] reduced learning and travel time, on-demand learning, student and instructor flexibility, faster revision, reduced delivery cost, and learner control.[2]

Initially, distance education was a print-based model of correspondence education. In the 1960s and 70s, distance education heavily relied on radio or television broadcasting. With the development of different technologies, distance education developed into interactive systems, which began with audio conferencing but progressed to more sophisticated systems that involved telephone audio, text and visual materials.[3] Nowadays, the new technology has brought distance education into a videoconferencing system. Using the videoconferencing technologies, distance education is able to have two way communications so that students are able to interact with instructors. Today, the application of satellite communications offers more possibilities for distance education and improves its efficiency and quality of the experience.

Satellite Communications

“A communication satellite is a microwave repeater station that permits two or more users to deliver or exchanging information in various forms.” [4] Satellites are capable of providing wide coverage and two-way communications with the same footprint over the same satellite network. In addition, by utilizing satellites for communication, receivers at different locations within the satellite network are able to receive signal without the help of terrestrial networks. The communication satellites can provide point to point communication and point to multipoint communication.

In terms of the operation of satellite networks, the characteristics of satellites are:
1. Wide area coverage: The coverage footprint of satellite breaks the boundary limitation. Countries, states, or areas are able to receive the signal at the very same time.
2. Broadcast: Satellites provide point to multipoint communication. A central control center can deliver messages/programming/video to individual receivers within the signal area.
3. Data distribution: Satellites are able to provide data casting services. The central control center can transmit data (general data, video, and audio) to other individual receivers at different locations one way or two ways.
4. A broadband capability: The wide bandwidth allows satellites to provide high speed transmission and the ability to store and forward data, which is called caching.
5. On demand: Through the satellite transponder, individual users are able to request data from the data center.
In general, satellite communication technology at this stage is mature and is highly suitable for distance education.

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