J2me-based Mobile Gis Systems Research And Development

With the development of mobile communication technology, mobile phone has become one of the mobile computing tools integrating Pocket PCs and communication. The functions which are conferred by phone have been extended to distributed computing, space positioning and other more high-level fields. Global Position System (GPS for short) integrating Geographic Information System (GIS for short) technology provides mobile phone users with positioning and navigation, and many other features, so it has very broad prospects for application.Based on the current fact which there are more than 60 percent mobile phone is Java mobile phone of the Bluetooth-enabled phone, a mobile GIS solution is provided based on the J2ME platform. Java phones and other mobile terminals can get the current latitude and longitude by an external Bluetooth GPS receiver, and the data is sent to the server-side; server application based on the latitude and longitude create a grid generated maps by calling the function of re-center (the map clearly marking the location of mobile terminals), Grid Map data to be returned to the client, so as to solve the mobile positioning and navigation problems. The modules in this system include maps service, location-based services and enquiry services. In view of public transport in the transfer path algorithm is the best city in a major road traffic problems, the bus transfer algorithm is given based on an aggregate computing for application in resource-constrained devices feature.The mobile GIS system based on C/S structure to achieve, MapInfo's GIS software MapXtream4.7.1 for Java is selected as a map server software, service-side applications are developed on the basis of API which are provided by MapXtream4.7.1 for Java software. Client applications are programmed based on the J2ME platform, the protocol between client and server is HTTP, the mobile communication network is a wireless network. A lot of tests are taken on the basis of map data in Beijing and the Beijing Public bus data. The actual tests are also taken in OS of Nokia N70. Test results show that the system has more practical, good reliability and further improve a good prospect.Of course there are still some imperfections in the system, due to a system of the client and server of the interactive data, particularly data larger map data, users will spend certain expenses, Image compression mode should be taken to reduce the capacities of transmission; if taking the Web Service technology, server interface will have a better compatibility.