Project Title: Towards Ubiquitous Location Services: Scalability and Privacy of Location-based Continuous Queries

Project Award Number: IIS-0811998

PI Name: Mohamed Mokbel
Department: Computer Science and Engineering
Institution: University of Minnesota
Address: 200 Union ST SE, Minneapolis, MN, 55455, USA

Project Abstract: Location-based continuous queries are the backbone for monitoring, alerting, and notification location-based services. The current technologies and software infrastructure behind existing location-based continuous queries are not designed to handle their formidable rise in usage nor to maintain the location privacy of their users. The goal of this project is to conduct research, develop requisite knowledge, and build software infrastructure to (1) scale up location-based continuous queries to deal with very large number of users, and (2) inject privacy-awareness in location-based continuous queries where a high quality real time answer can be provided without the explicit knowledge of user locations. The project achieves its goals using the following approaches: (1) employ a built-in approach in which location-based queries are realized as query operators inside a database engine, (2) develop adaptive location-aware query optimization techniques, (3) exploit shared execution and load shedding techniques for location-based continuous queries(4) exploit the trade-off between user privacy and quality of service, and (5) develop efficient privacy-preserving continuous query processing techniques. Applications will benefit from this project include location-based emergency response, intelligent transportation systems, traffic control, fleet management, and location-based advertising. The project supports PhD students to pursue research in the areas of location-based services and database systems. Related tutorials and workshops are organized. A new graduate-level course integrating the research results from this project is introduced. Publications, technical reports, software, and experimental data from this research are disseminated via the project web site(

   PhD Students:    Keywords:
  • Spatio-temporal databases
  • Location-based queries
  • Continuous queries
  • Location privacy

   Representative Tutorials:    Publications: