With the rapid popularity of mobile phone and personal data assistants (PDA), a number of network-based services are becoming available to these handheld devices, which deliver timely information and accept transactions and inquiries when the user is moving around, such as weather reports, stock quote triggers, or Email and pager notification. Among these, the real-time traffic information as well as the travel guide service is expected to be one of the most practical and promising ones. However, the present advanced traveler information systems (ATIS), which run on workstations or PCs, could not work well on these handheld devices due to the device and wireless Internet limitation. Aimed at lessening the influence of the limitations and make effective use of the handheld computing environment, this paper focuses on the spatial data issue and represent an alternative way to reduce the data amount with the least loss of information. Meanwhile, another approach is also brought forward on organizing the spatial data in an efficient way to reduce the data for network transmission on each request.
Abstract