Mobile map - Technology for Application

System Design and Implementation
The most important elements of successful mobile map applications is the availability of quality data content and a user interface allowing easy, accurate and quick access to that content. User interface design is a significant challenge for any mobile software development due to the limited device resources. In the design phase we focused on creating an intuitive interface based on requirements and recommendations from previous ethnographic studies on mobile applications practices and was of using information resources.

1-Database structure
The spatial and attribute data was stored in XML (eXtensible Markup Language) format.
XML provides a common data exchange format, encapsulating both metadata and data. This allows different applications and database to exchange information and communicate without having to understand anything about each other.

The initial task in the implementation phase was to convert the spatial data from ESRI shapefile to XML format. Each feature is stored as an object.Three types of objects have been defined:

  1. Point object , presents the services layer.
  2. Line object, presents the streets layer.
  3. Rectangle object, presents the districts boundaries.
As shown in (Figure4-M2), the services layer contains more than 1500 point in eight categories (hospitals-hotels-museums-clubs-cinemas-squares-malls-landmarks).

2-Functions definations
The main functions in the application can be summerized as follows:

  1. Map manipulation:zoomin,zoomout and pan.
  2. Identify any feature from the map and retrieve the information of the selecteed feature.This information can be text data or photo.
  3. Searching for a street or point of interest by specifying name perfix or by select from a sorted list of names.
  4. Clear selection of the selected feature.
As shown in figure (3), the user can use the mobile cursor keys (joy-stick) to scroll the map in the four main directions (right-left-up-down).The digit keys (1-2-3-4-6-7-8-9) can be used also to scroll the map in eight directions.

The '*' key can be used to select a feature from the map (Figure 4-M10) for example select a hotel , and the '#' key is used to retrieve the information about the selected feature (Figure 4-M4)(this information can be text data , photo or both).

The user can search for any service point or street by specifying name prefix (Figure 4-M5).The result is a list with such prefix.

By selecting any of these services, it will be marked and flashed with red color on the map.


Figure (3): The Keys functions in the application


3-User interface and menu hierarchy
Java-enabled phone interface design is very different from the design used for PC or Internet applications. System functionalities are organized in a hierarchy of nested menu options. Figure (4) shows the cascading menu for IbnBatota application. When users select a menu option, it takes them to a submenu with another list of available options. Users continue to navigate down the menu system till they hit the menu hierarchy node, which usually instructs the system to perform a function (e.g., locate a point of interest on the map or retrieve data about selected feature).


Figure (4):IbnBatota menu hierarchy


Conclusions
The increasing potential of mobile devices and the increasing requirements for location information go hand in hand.

In this paper we discuss the process to build a mobile map application running on 2.5G and 3G mobile devices by integrating XML and J2ME.

References
  1. Liu Yong, Li Qing Quan, Xie Zhi Ying and Wang Chong: Research of mobile GIS application based on handled computer, ISPRS Proceeding 2002.
  2. Java 2 Platform, Micro Edition (J2ME), http://java.sun.com/j2me/
  3. Mobile Information Device Profile(MIDP), http://developers.sun.com/techtopics/mobility/midp/
  4. Rainer Malaka, Robert Porzel, Alexander Zipf and Vasu Chandrasekhara: Integration of smart components for building your personal mobile guide. European Media Laboratory.
  5. Sonera MediaLab: Mobile java application development, 2002.
  6. Takino Shuichi: “GIS on the fly” to realize wireless GIS network by java mobile phone, International Symposium on Asia GIS 2001.

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