In location-based services, users with location-aware mobile devices are able to make queries about their surroundings anywhere and at any time. While this ubiquitous computing paradigm brings great convenience for information access, it also raises concerns over potential intrusion into user location privacy. To protect location privacy, one typical approach is to cloak user locations into spatial regions based on user-specified privacy requirements, and to transform location-based queries into region-based queries.
We study the representation of cloaking regions and show that a circular region generally leads to a small result size for region based queries. Moreover, the progressive query processing mode achieves a shorter response time than the bulk mode by parallelizing the query evaluation and result transmission.
Existing techniques cannot be used effectively in a wireless broadcast environment, where only sequential data access is supported. It may not scale to very large user populations. In an existing system to communicate with the server, a client must most likely use a fee-based cellular-type network to achieve a reasonable operating range. Third, users must reveal their current location and send it to the server, which may be undesirable for privacy reasons.
This System is a novel approach for reducing the spatial query access latency by leveraging results from nearby peers in wireless broadcast environments. • Our scheme allows a mobile client to locally verify whether candidate objects received from peers are indeed part of its own spatial query result set. The method exhibits great scalability: the higher the mobile peer density, the more the queries answered by peers. The query access latency can be decreased with the increase in clients.
- Network Module
- Wireless Broadcasting
- Location Based Services
- Privacy Query Processing