To appreciate the technology behind Digital Video Broadcast (DVB) system, its differences with the analogue system, and the additional features that can be supported, some level of understanding of the concepts and terminologies defined in the DVB standard is required. The challenge is that these concepts are typically very theoretical and dry. Students often find the concepts hard to visualize. Practical sessions were conducted using a real DVB system to demonstrate the process of preparing video and audio signals for broadcasting. However, as students listened (largely passively) and observed the instructors demonstrating the operation, the impact to their learning was limited. Many still could not answer the basic questions related to the DVB system posted at the end of the lesson.
In 2003, a project was launched to re-design the DVB practical lesson. The module development team set two main objectives for their task; to encourage active participation by providing students with hands-on experience, and to enhance students’ understanding of the important concepts behind DVB technology. To achieve the objectives, all students needed to be involved in the whole process of digital video broadcast; from pre-broadcast processing which involves the preparation of the raw video and audio footage for transmission, to actual broadcast through sending the processed signal to a DVB transmitter, and finally tuning the receiver to verify if the broadcast is successful. Using an existing commercial DVB system would be too costly and impractical. The team therefore decided to leverage on NP’s mobile e-learning platform and built two of the systems in-house; a Pre-Broadcast Signal Processing Software module, and Transport Stream Analyzer software. These software modules not only perform functions similar to commercial broadcast equipment, they also contain additional features that are designed specifically for learning purposes. The customized software modules could be installed on every student’s notebook allowing them to perform their own pre-broadcast processing. Students were now able to work independently at their own pace, creating different programs and sending them for broadcast using the transmitter. In the process, students got to troubleshoot and solve problems, and as a result strengthen their understanding of the concepts behind DVB technology. To help students relate what they have learnt to real systems, the newly designed practical lesson also required students to record and analyze the engineering information carried within the programs broadcasted by MediaCorp using the Transport Stream Analyzer. This encouraged students to explore beyond the scope of their curriculum. They showed greater enthusiasm and were motivated to find out more when discrepancies were found in the live broadcast from MediaCorp.
The re-designed practical lesson and the use of customized software had significant impact on students’ learning. They were more active during practical sessions and had demonstrated deeper understanding of the concepts involved. This is evidenced by the fact that while the assessments have become more challenging, students have been able to demonstrate their competence.