In heterogeneous service environment, E-learning, especially for learning content service, poses many opportunities and challengers of which the focus is that the service is even not able to be provided if the content can not be consumed in the service environment, termed service context also, which consists of the current state of networks, terminals, users, natural circumstance etc. To face the music, ISO/IEC proposes new standard, MPEG-21, in which content adaptation technology is employed to solve the problem of mismatch between content and...
