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STUTTGART

TECHNIK

Introduction 

        STUTTGART UNIVERSITY OF APPLIED 

SCIENCES 

In  this  application,  SVGT  and  J2ME  are  collaborating  to  design  and  implement  a 

cartographic WMS client for mobile devices.   

1.2  Problem definition 

1.2.1  Limitation of mobile devices 

The  popularity  of  handheld  devices  and  mobile  Internet  gives  a  new  platform  to 

geoinformation. But cartographic visualization for small displays of mobile devices is 

restricted by several technical limitations such as the small display size and resolution, 

lack  of  processing  power  and  memory,  most  critical  the  battery  life,  and  the  mobile 

network  bandwidth.  When  writing  J2ME  codes,  those  limitations  should  be 

considered, especially for memory, screen size, and network bandwidth. 

1.2.2  XML document parsing 

Once the users send the GetCapabilities Request to the WMS, the client gets a XML 

format file as the responded data. The parameters of the GetMap Request URL in the 

content of this XML document should be picked up and be set in the GetMap Request 

URL.  Because  every  WMS  has  its  own  Document  Type  Definitions  (DTD)  for 

GetCapabilities  Request  XML  document,  it  is  a  big  challenge  to  find  one  common 

solution to parse those different XML document. 

1.2.3  SVGT/PNG Viewer using and designing 

To  display  the  result  map  file,  SVGT 

TinyLine

  or  PNG  raster  image  format  viewer 

will be loaded depending on which kind of image formats supported by the WMS. 

How  to  implement  the  Tinyline  SVGT  viewer  as  one  embedded  part  of  the  client? 

How to read and redraw the PNG image file?   

1.2.4  User interface designing 

This  client  should  be  designed  as  one  complete  WMS  client  with  full  functions  that 

are same as the PC client. Thus it should include several basic interface for the users 

to  select  server  address,  input  coordinate  of  the  search  point,  select  layers  and 

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