路网环境下的移动对象查询技术研究综述

随着基于定位服务（Loaction-Based Service，简称LBS）在移动设备上的广泛应用，移动对象在路网中的查询成为时空数据检索领域的一个研究热点.本文从索引结构、查询方法和隐私保护三层面对基于路网的移动对象查询技术进行了分类讨论.索引结构分为分层索引、分布式索引和广播索引并对三种索引进行对比和分析；查询方法分为单对象连续查询、多对象并行查询、最短路径查询和路网关键字查询并归纳了每种查询的解决策略；此外，阐述了路网移动对象查询中采用的隐私安全保护措施.最后，分析了未来路网移动对象查询研究所面临的挑战.

Review on Moving Objects Query Techniques in Road Network Environment

Currently, LBS (Location-Based Service) is widely employed in many mobile devices, making the technology for processing moving objects data underlying the road-network become a research hotspot, within the community on spatio-temporal processing techniques.In this paper, we intend to survey the previous work from three aspects, including the index structures, the query approaches and the privacy protection.First, we classify the various index structures into three groups:hierarchical, distributed and broadcast, then make comparisons based on the in-depth analysis.Second, we divide the query approaches into four categories by their purposes, including the single-object continuous query, the multi-object parallel query, the shortest path query and the road-network keyword query.For each category, we further induce its basic strategies.Afterwards, methods on moving objects''privacy protection are also studied.The challenges on these technologies are forecasted in the end.