Access control mechanisms protect sensitive information from unauthorized users. However, when sensitive information is shared and a Privacy Protection Mechanism (PPM) is not in place, an authorized user can still compromise the privacy of a person leading to identity disclosure. A PPM can use suppression and generalization of relational data to anonymize and satisfy privacy requirements, e.g., k-anonymity and l-diversity, against identity and attribute disclosure. However, privacy is achieved at the cost of precision of authorized information. In this paper, we propose an accuracy-constrained privacy-preserving access control framework. The access control policies define selection predicates available to roles while the privacy requirement is to satisfy the k-anonymity or l-diversity. An additional constraint that needs to be satisfied by the PPM is the imprecision bound for each selection predicate. The techniques for workload-aware anonymization for selection predicates have been discussed in the literature. However, to the best of our knowledge, the problem of satisfying the accuracy constraints for multiple roles has not been studied before. In our formulation of the aforementioned problem, we propose heuristics for anonymization algorithms and show empirically that the proposed approach satisfies imprecision bounds for more permissions and has lower total imprecision than the current state of the art.

As demand for networked multimedia applications is increasing rapidly, it is important to provide these services in mobile communication environments. In this paper, we identify system requirements for base stations in order to support multimedia services. These requirements include supporting concurrent connections for multiple users, allocation of resources dynamically to satisfy diverse resource requirements for multimedia applications, and reallocation of resources during handoff incurred by user movement or newly generated calls. These requirements can be used to design an interface between land-based and mobile environments to handle one of the most challenging issues in multimedia communication: enforcing interstream and intrastream synchronizations. We propose two quality of presentation (QOP) parameters for evaluating the quality of mobile multimedia connections, and analyze the validity of these requirements.>