Developed countries have long been interested in distance education. This interest is growing due to the advance toward a global economy, because education is commonly regarded as the best way to maintain a region’s competitiveness. Thus, we have recently witnessed a great development of e-learning (taken as a synonym for Web-based learning, or learning through an Internet-enabled computer) to the point that using the Internet to deliver educational material has practically displaced the early initiatives based on postal mail, radio, or television. The initial evolution of the Internet led to envisaging a massive adoption of e-learning solutions. However, as proved by data from Internet World Stats (http://www.internetworldstats. com), the penetration of the Internet in homes has been rather limited (around 35% in Europe and 67% in the USA), so it follows that the penetration of e-learning has been limited too. This is indeed one consequence of the socalled digital divide, that is, the separation between people who make frequent use of the information technologies and those who have no access to them or, even having access, lack the necessary knowledge to use them. A divide in the access to technology can lead to inequalities in the access to knowledge and education, posing risks of social exclusion. To prevent that, public administrations have launched large-scale initiatives, like the World Summit on the Information Society and the i2010 plan, that aim at making technology available to everyone, at anytime and from anywhere. As a cornerstone, these initiatives promote the development of access platforms different from the PC, with special interest in harnessing the interactive features of devices that have attained greater penetration in society. This includes the new digital TV set-top boxes, which bear the term t-learning, and the modern mobile devices (e.g., mobile telephones and media players), which set the foundations for m-learning. The vision, as represented in Figure 1, is that the information technologies, combined with suitable pedagogical and andragogical approaches, will enable a scenario of ubiquitous and lifelong learning, freeing people from time and place constraints, and offering flexible learning opportunities to individuals and groups. This article describes technical, methodological, and educational issues that make t-learning and m-learning substantially different from previous works on e-learning. We also review developments in both areas to finally discuss problems that may be the subject of much research in the near future.
Rural Online Distance Education based on Content Delivery Network in Beijing