Technological Challenges in Distance Learning
September 2008

Technological Challenges in Distance Learning

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Arvind S Patil

Technical Officer

The distance education initiative of the Indian Institute of Technology (IIT) Bombay has been in operation since 2002 and its core strength is live interactivity between teachers and students with the use of the best of what ICT has to offer.

The expertise of exceptional teachers at IIT Bombay is being tapped with the use of satellite and internet technologies. Thus addressing a gap that exists between the demand of expert faculty and need for quality education across regions. In other words, the interaction between teacher and student is being extended outside the classroom using technology.

Efforts are on to make the traditional classroom kind of interaction available live at the individual level. The number of classrooms from where the transmissions could happen could be increased substantially. Efforts are on to make all classrooms at the institute digitally interactive.

An exponentially expansion of this model is viable if other institutes start using newer technologies. This article will provide insights into the current technologies in use; discuss the challenges as faced while offering education in distance mode and possible next generation technologies which could be roped in to address these.

Current technologies

Two basic technologies used in distance education are satellite and internet. IIT Bombay has been using satellite based-technology for the last seven years for reaching remote areas not so well connected even today.

This is how it works: Signals are generated at a ground station and beamed to the satellite kept in geostationary orbit about 36000 km away above the surface of the earth. The satellite is always in the line of sight of the ground station and receives signals constantly.

The satellite in turn can transmit the signal received to far away places through the transponders on the satellite.

The EDUSAT launched by ISRO was made available to transmit courses from IIT Bombay on its extended ‘C’ Band channel. Initially, the bandwidth was shared with two other programmes on the same channel but with the growth in the activity from IIT Bombay offering as many as 13 semester long courses; the entire bandwidth of 1 MBPS was made available to IIT Bombay.

The working arrangement of the EDUSAT communication is shown
at Fig. 1

Following is the cost wise break-up: the receiving equipment set cost ranging from Rs. 10 to 20 lakh, reducing with time. The bandwidth charges ranged from Rs. 21 lakhs to Rs. 39 lakhs; again reducing with time.

Internet and web based transmission picked up in India after it became affordable and available. Typical MTNL internet lease line annual charges are shown in Table – 1. below:

Participants are increasingly demanding courses through internet as this is more affordable. Though the web technology is well established in the West, the feature that is added at IIT Bombay is of interactivity between the participants and the teachers, and also between the participants themselves.

Interactivity in satellite transmission is the niche of IIT Bombay’s distance education programme that has an edge over other distance education programmes.

In a way it simulates a typical classroom session at many places and entire groups of participants become part of an extended classroom.

The second live interactive technology used at IIT Bombay is video conferencing over the internet. It has limitations on the number of users who can simultaneously connect as it is dependent on the bandwidth available.

The bandwidth gets shared between the users and hence a larger bandwidth is required at the transmission point. With 2MBPS leased line up to 40 locations could get connected by using additional equipment like MCU and using software to achieve compression and decompression of data.

The communication is simultaneous. The offline interaction is arranged by a Learning Management System called ‘moodle’ developed by Mr. Martin Dougiamas of Australia; available in open source and used as effective support to live interaction.

The instructor or teacher controls the communication through moodle. There could be number of teachers for a single course. The participants, as decided by the teacher, are given a login in the moodle page of a particular course and then only they are able to post questions, answer questions posted by others, correct or debate answers given. The teacher could post the lecture-wise presentations progressively through moodle for the benefit of those who may have missed a live session.

The quizzes, examinations could be conducted through moodle. Previous question papers could be posted for solving by the participants collectively. Any other communication possible through internet is possible in moodle.

The support in the learning is possible by providing the course content as compressed audio video files on portable media like VCD or DVD. This is termed as offline classroom. The course could be viewed at Remote Centers asynchronously and interacted though LMS.

Additionally, limited live interaction between the course instructor and the participants is possible at a scheduled time using satellite transmission or internet based video conferencing. This methodology is increasing rapidly as matching course delivery schedules at all remote centers is avoided.

The course content supplied by IIT Bombay is a good support material to supplement the study material used by the local instructor. This helps the local instructor and the receiving institute to take care of its curriculum while receiving courses from IIT Bombay.

The other technology available is to enable courses receiving by a participant through DTH. DTH or Direct to Home as it popularly known uses Direct Broadcast Satellite Service for transmission. So, the issues related to satellite transmission are common to Live Transmission and DTH to a large extent. The recipient is directly connected to a satellite broadcast and receives the same through a dish antenna directly at home.

The broadcast is non-interactive at present but efforts are ‘on’ to make it interactive. The Video on Demand (VOD) feature of DTH is gaining popularity as it facilitates viewing of the lectures at one’s convenience.

Challenges faced

The live interactivity through satellite is manageable with about 100 receiving terminals (SITs) of EDUSAT connected and would be meaningful if about half of them join a particular course transmission on an average. The number of SITs is limited by the infrastructure that is required to be in place for reception.

There is practically no limit on number of SITs otherwise. The quality of Video which is at present a constraint and is because of the input to the satellite codec is in analog form. Once the input signal gets changed to digital; there shall be remarkable improvement in the quality of video at the receiving end.


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