DISTRIBUTED SMART APPLICATIONS: AN ARCHITECTURE FOR AN E/M-LEARNING-BASED VIRTUAL CAMPUS SCENARIO
C. De Castro
IEIIT-CNR, National Research Council of Italy (ITALY)
Future campus scenarios can be regarded as distributed smart applications, mainly based on e/m-learning web platforms, heterogeneous devices and supported by properly managed network infrastructures.
Far from disregarding the essential role of face to face communications between teachers and students, campuses are considered as distributed scenarios, meant as virtual spaces where groups of people within colleges or private locations (the students’ homes and teachers’ offices) can interact.
As several e/m-Learning web platforms show, advanced applications of this kind involve heterogeneous services, ranging from chat to videoconference, joint remote access to distributed laboratories, workgroup with file sharing, etc. Such activities are often cohabit during different periods of a lecture or session study and the network must guarantee an appropriate connection quality to everybody.
In the following, some distinct situations that can occur during a lecture are depicted; in consequence, a proposal is made which aims at giving a suitable Quality of Service (QoS) in all such situations. Applied to e/m-Learning, QoS techniques must guarantee an appropriate communication quality to every learning activity, ranging from lectures involving voice and video to real-time groupwork activities.
In the context of a remote lecture, the teacher, with his or her voice and “writing” (blackboard, pc desktop, virtual blackboard, slides, etc.), must be properly seen by all the students. On the contrary, some questions can generally require to be heard only.
Many variants can be imagined: for instance, students can have slides stored on their devices and the teacher may decide to explain them with or without being filmed.
Again, during fully interactive activities, such as exercises, both the teacher and the students, their voices and “writing” must be at everyone’s disposal. In some cases, as above, commenting an exercise or a scheme and the voice only modality can be enough.
Another example is remote and distributed laboratory activities, where the teacher, students and instrumentation are distributed over distinct locations. In case the teacher explains an experiment, his video, voice and the instrumentation control are enough, with some voice-only students’ question. In case the whole class, in groups, and the teacher make an experiment at the same time and need also to interact with each other, video, voice and desktops must be at the teacher and each group’s disposal.
Each of such activities require a different bandwidth at disposal and, in consequence, the bandwidth required vary over time on the basis of people, groups and activities currently in progress.
QoS, thus, is not managed only on the basis of the user’s or group’s profile and access rights, but also of the kind of activity currently in progress during a lecture and people involved.
The proposed architecture, thus, tailors the QoS system to the following time-varying variables: kind of task currently in progress and people involved in the task, and consequently adapts service release on the basis of the actuals needs dictated by these two factors.