Abstract:

The increasing availability of rich multimedia contents from the Internet is playing an important role in several services. Consider for instance smart applications for the Cultural Heritage, currently used in many fields, such as tourism and home entertainment. Such applications are full of interesting contents, that can be used in e/m-Learning activities, for instance in the field of History of Art. This case is here discussed, and the following scenario considered: a teacher and his or her students use an e/m-Learning system, where contents from the Cultural Heritage are adopted, such as HQ images or videos available on the Internet. Teachers choose which visual information must be accessed; students follow lessons from home or outside, using:
(1) heterogeneous devices, such as desktops, laptops, tablets and smartphones, and
(2) different network access connections, such as a WiFi from a 100 Mbps wired or a 20 Mbps DSL or LTE.

The learning goal is to enjoy rich and detailed contents properly, for instance in History of Art lessons. In this case, HQ images or videos need to be accurately displayed. The problem is particularly important of visual quality, which depends on several factors, such as screen resolution and network access speed, especially if high-bandwidth demanding contents are accessed in real-time.

Contents are meant to be shown to a class, but each student accesses the system using his or her device and network access technology, which can both vary over time depending on where and how students log on to the system. In consequence, the possibility to access the requested visual information properly or not must be checked for each individual, according to distinct situations and learning tasks.

This paper focuses on two specific and related aspects concerning quality of advanced visual contents from the Cultural Heritage and their use in smart education environments (images and videos).

First, the concept is investigated of “Perceived Quality of Service” (PQoS) in visual environments. An early architecture is consequently proposed for the dynamic management of bandwidth release on the basis of content size and duration.Quality of image and video transmission, in particular, are related to both bandwidth required and access technologies, and the following considerations can be made. First, Smart Environments are increasingly being enjoyed through mobile devices and wireless networks; second, contents from the Cultural Heritage are increasingly bandwidth-demanding. The network and its performance, thus, are fundamental. The same applies to device quality, such as screen size and resolution.

All such factors contribute to the final perception. In particular, an appropriate transmission and reception of videos strongly contribute to the user’s overall perception. QoS management, thus, here meant as an appropriate bandwidth distribution, becomes a focal issue in PQoS. This is particularly important when groupwork activities are scheduled, such as lessons involving the simultaneous vision of high bandwidth-demanding contents. As a matter of fact, the lesson is address to a group, but, since each student is free to access information using his or her device and network access technology, supervision concerns individuals.

Keywords:

Perceived Quality of Service, Smart Applications, Cultural Heritage, e/m-learning, Quality of Service Management.