A framework for dynamic updates of map data in mobile devices

Stored map services in mobile devices are being commercialized for mobile and wireless environment such as cellular phones. In order to ensure the quality and accuracy of map, the update on the source map must be reflected automatically to mobile devices. Due to the expensive communication cost and lack of hardware capacity of mobile devices, we should find a compromising solution between the transmission of an entire map and the transmission of only update logs to mobile devices. The transmission of the completely processed whole map results in an expensive communication cost, while simple transfer of update logs requires a large amount of processing to maintain geometric and topological consistency between multiple LODs(Level of Details). In this paper, we first propose a framework of update mechanism in mobile environments where the map data is stored on each mobile device. This framework provides an efficient strategy for processing an update and its propagation to multiple LODs without an expensive cost of communication and large amount of processing at mobile devices. Secondly, several methods are introduced to maintain topological consistency between LODs depending on the type of generalization operators. Finally, we propose an extended SVG(Simple Vector Graphics) to be used as a transfer format of update message to mobile devices.