The Design And Realization Of The RealTime Traffic Information System Based On LBS

Mainstream use of private cars in our modern society is deteriorating the heavy traffic, causing huge waste of resources and severe air pollution, which calls for realtime traffic information system. Location Based Service (LBS), which integrates theory and technology of GIS, telecommunications, IT etc, and shipped with popular smart phones, provides value-added service related to user's locations. Real time traffic and LBS are to be bound together such as to develop a real-time traffic based LBS information system, to better improve user's experience and enhanced functions.By employing Symbian, the No. 1 market share of Nokia cellphone OS, the system developed in this paper implements an LBS information system based on real-time traffic, combing GIS and LBS techonology, and the real-time traffic information, which proves to be much more applicable and innovative.The paper analyzes the application demand and focuses on its functional and GUI design. Characteristics of real-time traffic is analyzed and the transferring format of traffic data stream is defined. The longitude and latitude readings of the mobile terminal is required by using the Location API, which is available in Symbian OS. Location information (including longitude, latitude, the zoom level) is sliced into map tiles with Mercator projection. HTTP protocol is employed to query for target location's map tiles with specific query strings, and to receive theα-channel-enabled raster maps, which includes the basic traffic map and real-time traffic information. Maps with daily life information is also populated according to specific entities. All these maps are synthesized into a merged map layer in the working buffer by the image processing mechanism in the Symbian OS. The derived map layer is displayed in smart phone where real-time traffic and background raster map can be toggled on or off.The paper is composed of 6 parts. Part one elaborates LBS based real-time traffic information system design. The brief content and structure of the paper is also discussed. Part 2 focuses on the research review of related technologies and models, including LBS, ITS, smart phone OS (Symbian), mobile e-map application,etc. Part 3 discusses the system's demand analysis, functional description, and its GUI design. In part 4 the paper develops the information system, including data preparation, map's displaying style, acquisition of all sorts of maps and location information. Part 5 focuses on the system's debugging and evaluation, also its optimization. In part 6 the system's strength and weakness is discussed and some interfaces are preset for system's extension.The paper successfully develops a real-time traffic based information system running in the Symbian OS, which proves to be a insightful research on the mobile-GIS developing for the smart phone OS. The field this paper focuses overlaps with various fields, which calls for profound development in GIS and tuff challenges for related disciplines.