Abstract:

This article presents an exercise on the implementation of a small telecom network for the transmission of TV signals. The aim of the exercise is the students to review essential telecom concepts and processes (such as digital conversion of analog signals, feasibility of fiber transmission, fiber allocation to users, international transmission issues etc.) and use them for the planning of an actual telecom network even at a small scale. The exercise itself is part of the general attempt to bridge the gap between education and engineering profession given the fact that the implementation of a telecom network is an activity that a future electronic/telecom engineer will often encounter in his/her professional life.

The exercise anticipates the interconnection of four (4) venues with a central node, called the International Broadcasting Center (IBC) from which the TV signals can be broadcasted home and abroad. The particular issues the students will deal with together with the respective educational aims are the following:
• The digital conversion of PAL TV signals which will make students practice on basic parameters regarding A/D (PCM) conversion of composite video as well as audio signals.
• The transmission of the digital TV signals from each venue to the IBC by means of fiber-optic links. This will make the students practice on calculations regarding power budgeting, possible limitations due to chromatic and polarization-mode dispersion, the technical characteristics of transceivers etc.
• The deployment of a core fiber cable (to cover the area between the venues and the IBC) and the allocation of fibers to the venues depending on the transmission requirements.
• The interconnection of each venue to the core cable which will make the students work on the required passive optical equipment and its basic parameters.
• The transmission of the TV signals from the IBC to telecom operators at home and abroad. Regarding international transmission, the students will have to examine whether it is preferable to use international fiber networks or satellite links (or a combination of both), handle back-up issues and, regarding satellite transmission, to work on topics such the signal compression and the choice of the proper modulation technique.

Apart from the planning itself, the students will be asked to compile a list of materials necessary for the implementation of the network, taking into account additional issues such as the necessary back-up regarding venue and IBC equipment, fiber cabling and international transmission. The aim of this particular topic is the students to search for available equipment and get a feeling of the financial aspect of the assigned project.

All in all, the exercise, by making the students associate acquired theoretical knowledge with actual telecom applications, it is expected to enhance this knowledge, improve students’ engineering aptitude and help them develop a better feeling regarding the planning of telecom networks.

The exercise will be included in either the “Optical Communications” or “Broadband Telecommunications” course offered at the 6th and the 9th semester of the Dept. of the Electrical & Electronics Engineering Dept., School of Pedagogical & Technological Education (ASPETE), Athens, Greece and, based on available teaching time, it could be offered through the blended learning approach.

Keywords:

Engineering Education, Electronic Engineering Education, Telecommunications, Optical communications.