Editorial: Advanced intelligent and security services in mobile and ubiquitous computing

Today research and industry communities are aiming at establishing mobile and ubiquitous computing (MUC) in order to address the emerging needs of the information society. MUC provides the foundation of a “human-oriented communication environment,” where people can get online anytime, anywhere, thus having permanent access to their preferred services. With an immense potential to revolutionize our lives, MUC also poses new research challenges. This special issue concentrates on recent advances and significant contributions to all aspects of the MUC field with an emphasis on forthcoming intelligent and security applications. The issue is composed of six papers, which are significantly extended versions of the original submissions presented at the 3rd International Workshop on Intelligent, Mobile and Internet Services in Ubiquitous Computing (IMIS 2009) held in Fukuoka Institute of Technology, Japan in March 16–19, 2009. The first article, “A Hybrid Scheduling Scheme for Data Broadcast over Single Channel in Mobile Environments” by Song-Yi Yi et al. introduces a hybrid data broadcast scheme based both on the semantic relationships between data items and the access probabilities. This scheme generates a broadcast schedule, which places semantically related data items together and broadcasts popular data items several times by replicating them in a broadcast cycle. According to the completed simulations, the proposed scheme is efficient with respect to the data access time.