中文摘要：

For the past few years, there has been an explosion in the number of individuals carrying wireless devices that are capable of conducting location-dependent information services (LDISs) and provide information based on locations specified in the queries. This paper examines the user's demand of vague queries, and then proposes system architecture of LDISs. In particular, based on D-tree index structure, it takes the method of membership function in fuzzy set theory to provide a more user-oriented approach to constructing overlapping location-dependent data regions, called complementary void overlapping data regions. This structure, carrying more information with less additional storage, brings balance between perceived usefulness and responsiveness, energy consumption, and bandwidth contention in wireless communications. The simulations show that this method is more flexible and practical in practice.