Databases Reference
In-Depth Information
2 System Architecture for a Mobile Application
Environment
We assume the system in a location service environment comprises of the
following components.
Location Service
Server Process
Access Control Evaluation module
2
Unified Index
Query
Authorization DB
Moving Object DB
3
Retrieve
MO Data Processing Module
Static Requestors
Mobile Requestors
Fig. 1.
System Architecture for Mobile Applications
Location Service (LS):
We assume that there exists a location service that
maintains the mobile customers' location and profile information, and LS is
a trusted third party as in [16]. The current location of moving objects are
stored and updated accordingly in order to provide most up-to-date location
information to a requester. In this architecture, we assume that the moving ob-
ject data is represented using the Moving Objects Spatio-Temporal (MOST)
model [12] due to its simplicity and popularity in the literature. The contin-
uous movement of mobile objects makes maintenance of location information
extremely challenging. In the MOST, location information is treated as a
dynamic attribute and is represented as a linear function of time [16]. This
approach reduces the update frequency because the location information is
updated only if the predicted location deviates from the actual location more
than a certain threshold. Location information can be directly provided by
users' mobile devices using wireless communication periodically, or acquired
