Spatial Data Infrastructure (SDI), Wireless GIS

Spatial data infrastructures (SDI) providing geospatial web services as well as mobile GIS software become more and more popular. Fields like disaster management require the use of SDIs as well as of mobile applications. However, the scarce resources of mobile devices in respect of memory size, computing power, display size and communication bandwidth make an integration difficult and obstruct many desirable applications. In order to solve this problem, a three-tier architecture is proposed that allows an effective use of geospatial web services by mobile clients. The paper presents the main tasks and operations of the middle-tier, the so-called Mobile Data Service (MDS). Exemplary requests illustrate its functionality. Finally, essential implementation issues of the MDS are presented