GIS as a tool for Mobile Tracing and Routing Dr. Rajiv Gupta Professor Civil Engineering Group BITS, Pilani rajiv@bits-pilani.ac.in  S A Sandeep Murusupalli Final year undergraduate student Birla Institute of Technology and Science (BITS), Pilani (India) Sandeep_speaks@yahoo.co.in  Anil Kumar Kolluri Final year undergraduate student Birla Institute of Technology and Science (BITS), Pilani (India) anil_kolluri2002@yahoo.co.in Pradeep Kodali Final year undergraduate student Birla Institute of Technology and Science (BITS), Pilani (India) pradip1729@yahoo.com ABSTRACT This paper explicates how GIS can be used in providing the mobile user with an important location based service. The application discussed in this paper provides the user with the shortest path between the starting point and the destination. An inexpensive method in which GIS has been used for mobile tracing was devised. The beauty of this project lies in bringing together a gamut of efficient softwares like java servlets, wml and avenue scripting. Finally the paper looks into the various other possible applications that can be achieved using the latest technological advancements 1. INTRODUCTION This paper discusses the essence of the application developed by the authors making use of the GIS software. Geographic Information systems (GIS) techniques offer an effective approach, allowing quick remodeling for slight changes in siting criteria and produce results as maps eminently suitable for presentation at public enquiries. So, exploring this GIS software and developing the application with arcview as the platform has been touched upon in the first few sections of the paper. The GIS software has been effectively used to dynamically show the path between any two points in a given city. The results can be obtained either in text format or as maps. In the application the result has been presented in the form of a jpeg image containing the map along with the path, which is created afresh each time a query is made. Embossed maps used for topographic visualization, is very difficult, costly, time consuming and so visualization was done digitally faster, cheaper and continuously using GIS. The various other soft wares that have been used in the making of this application and the details pertaining to the linking of these to serve our purpose have been talked about. To develop a wireless application which enables us to query for user data through a mobile device i.e. an end user or a client has pushed us into exploring cell simulation soft wares like WINWAP and html to wml converters. To make use of this facility using the mobile requires a minimum of a GPRS connection in the mobile. The GPRS phones enable us to use the multimedia services such as Multimedia Messaging Service which facilitates the transmission of messages containing pictures, text and images. The last few sections of the paper concentrate on the method which would be needed to put this software on wheels have been mentioned in the paper. 2. Problem Definition Location Based Services (LBS) are services that are triggered by the current geographic location of the mobile user and his surroundings. LBS are generally information services accessible through mobile phones. The main objective is to develop a wireless application that enables us to query for user data through a mobile device which will be the end user or a client. Here in this context user comprises of the people wishing to find the route to his destination, who would be required to input the starting and the destination points between which he/she wants to find a path. The results can be obtained either in text format or map. Also it can be extended for maps such as users can query for the desired landmark and get the route to that landmark from his position. 3. Exploring the Solution One obvious and easier solution to this problem could be having a set of predefined points and asking the user to select the points from within this set and displaying the resultant path in form of map which would be stored in the database for the given set of two points. If, using this approach, to provide the path between any two points in the campus with each map representing the path between the two selected points, the data base has to accommodate ( n * (n - 1) ) / 2 maps, where n is the total number of points identified on the BITS campus map. If let’s say, there are some hundred points the number of such maps to be accommodated in the data base would be 50 * 99, i.e. approximately 5000 maps. In any realistic situation the number n would not be any thing lesser than 100, making this approach tedious and virtually impossible. Keeping in view the above mentioned limitations, the authors have come up with an entirely new solution to the present problem, taking full advantage of the versatility, of GIS software. The key objective is to develop an application, which would dynamically provide the path between any two points entered by the user. What has been even more challenging was the fact that this objective is to be realized with GIS in the core. The steps involved in attaining the objective would sum up to
 Fig. 2.1: Flow Chart In the next few sections a brief introduction about the Technologies and the software used in developing this application is given. After which the development of the application will be discussed in detail. 4. GEOGRAPHICAL INFORMATION SYSTEM According to Huxhold & Levinsohn (1995), "A geographic information system (GIS) is a collection of information technology, data, and procedures for collecting, storing, manipulating, analyzing and presenting maps and descriptive information about features that can be represented on maps." The technology required to construct a GIS is not just a single piece of software purchased from a vendor; it is a combination of information technologies including: GIS, computer aided design, database management systems, remote sensing and image analysis, GPS, multimedia and computer hardware. GIS were developed because data stored in a database only are not easy to interpret or manipulate. Therefore visualizing data as maps is the best way to understand, query or modify such data, especially for data related to a geographical space. Examples using GIS can now be found in many different domains, such as emergency services, environmental monitoring and modeling, businesses like LBSs, or industry applications such as visualization of underground pipes or other facilities. In fact, a GIS can be applied wherever spatial data analysis is needed. GIS helps to make better decisions by virtue of a range of built-in query, analysis, and map presentation functionalities. For example, a GIS can be used to make a decision about the location of a new housing development so that it may have minimal environmental impact or is close to a population centre. The information can be presented succinctly and clearly in the form of a map, allowing decision makers to focus on the real issues rather than trying to understand the data. Because GIS products can be produced quickly, multiple scenarios can be evaluated efficiently and effectively. 5. Servlets: Servlets are Java technology’s answer to Common Gateway Interface (CGI) programming. They are programs that run on a Web server, acting as a middle layer between the requests coming from a Web browser or other HTTP/WAP client and databases or applications on the HTTP/WAP server. Their job is to:
In a way Servlets are used as a bridge between the GIS application written on the back end and the front end application which is the HTML or WML pages, accessing the server through WAP. 5. Working of Mobile Phones When a user makes a call on mobile phone, it emits radio waves (also known as radiofrequency or ‘RF’ energy). These radio waves are received by the antenna of the nearest base station. A base station consists of one or more radio transmitters and receivers as well as radio antennas that communicate with individual mobile phones in the area. Once a base station receives the radio waves from a mobile phone, it forwards these to another point (called a ‘switch’) which then forwards the call to another base station or to the fixed line network depending on the type of call being made. Base stations have two limiting factors – one is the capacity of calls that they can handle, and the other is the geographical area that they can cover. To overcome these limitations, base stations are located in strategic areas, known as ‘cells’. Base stations, when correctly located; allow the available radio frequency to be reused in other cells, thereby allowing the network to handle many more calls. It also means that the base station must operate at low power levels so that it does not interfere with other base stations in the area. The important thing about base stations is that regardless of the type, they operate on low power levels, and where people can be exposed to the fields, they are far below the relevant safety limits. Base stations can only handle a limited number of calls even using advanced technical processes. Therefore the overall number of base stations is determined by both the technology and the number of people using mobile phones 6. WML (Wireless Markup Language) With the popularity of mobile devices, many of the sites are hosting web pages suitable for accessing via WAP browsers on these devices. WAP browsers can process and display web pages coded in WML or Wireless Markup Language. Short for Wireless Markup Language, an XML language used to specify content and user interface for WAP (Wireless Application Protocol) devices; the WAP forum provides a DTD (Short for Document Type Definition). A DTD states what tags and attributes are used to describe content in an SGML document, where each tag is allowed, and which tags can appear within other tags. For example, in a DTD one could say that LIST tags can for WML. WML is supported by almost every mobile phone browser around the world. For Web servers to serve WML pages, they must contain the text/vnd.wap.wml mime type MIME (Short for Multipurpose Internet Mail Extensions), a specification for formatting non-ASCII messages so that they can be sent over the Internet. Many e-mail clients now support MIME, which enables them to send and receive graphics, audio, and video files via the Internet mail system Wireless Access Protocol (WAP) Wireless application protocol (WAP) is a technology that allows users to access and interact with information and services instantly on their mobile handsets. WAP works in a similar way to a computer accessing the Internet. The primary language of the WAP specification is WML, which has been designed from scratch for handheld devices with phone-specific features following XML guidelines. WAP can be defined as a communications protocol that formats web data for transmission over wireless internet connections. WAP is a standardized technology for cross-platform, distributed computing, similar to the Internet's combination of Hypertext Mark-up Language (HTML) and Hypertext Transfer Protocol (HTTP), except that it includes one vital feature: optimization for low-display capability, low-memory and low-bandwidth devices, such as Personal Digital Assistants (PDAs), mobile phones and pagers. The Complete Picture This is what happens when you access a Web site using a WAP-enabled device:
Different technologies were discussed in the earlier sections like GIS, WML, J2EE, etc. This section explains how these technologies were effectively used in providing a user friendly and dynamic Location Based Services to the mobile users. The user, who is using a cell phone that supports GPRS, will be able to access the application which will be available in form of a WML page hosted in a public domain. So we start by providing the user with a WML page that consists of a map of the BITS campus, and two text boxes requesting his choice of origin and destination. The user enters his choice and clicks a button, which contacts the server through Wireless Access Protocol. The server initiates a Servlet that can read the values the user entered in the WML page. On clicking the button, the WML browser contacts the Server which should be java enabled. To achieve this, J2EE server or Apache Tomcat server should be running in the background. The server would now load the Servlet into the memory space. The Servlet initiates a series of events which are
8. Case Study The application has been tried up on BITS campus. A map of the campus is obtained and is digitized in order to obtain the road network of the campus. A point theme is developed with different points. The points, even though they are predefined, cover all the main locations of the campus making the software developed practically very useful. This map is displayed in a WML page with a proper labeling.  Fig 8.1. Screen shot of the WML page with the map. The user after giving his choices will click on the find path button and the WAP browser then contacts the server which was on of the BITS computers in which Apache Tomcat server will be running. This server will host the Servlet described in the previous section. The Servlet will embed the points entered in the WML page into the GIS project and run the project.  Fig 8.2. Screen shot of the GIS project The project finally executes the script written in avenue scripting and generates the path between the given two points in the form of a jpeg image.  Fig. 8.3. Output image with Blue line showing the path 9. Conclusions and further work This application is a clear example of the upcoming technologies and the growth in the level of innovation in transportation. With the number of mobile user growing day by day, this would help people overcome even the smallest problems they face in learning the routes to destinations. The developed method is completely user friendly and can be implemented easily in any city. Before implementing in a new city, it is necessary to do some ground work regarding road networks and cellular facilities in that particular city. It is also required to develop a theme in Arc View. The Servlets developed and the wml or the WAP code can be used as it is without any change. The process used here can always be improved and further additions are always welcomed. To implement this project in the BITS campus, this project needs to be installed on the World Wide Web. For this purpose, it is necessary to install the algorithm on a website and the server maintaining the website should have Apache-Tomcat running. Also Arc View must be installed in the server. The website of the project must be accessed by a web enabled phone. For this purpose a GPRS connection may be required. For implementation of mobile tracing in the project, it is necessary to tie up with the service providers. The application can be further enhanced to incorporate zooming and panning. The view in the cell phone is generally very small. So zooming and panning would always help the user to clearly understand the map. In this project to find the best path Arc View has been used as a tool. Every time a user asks for a path, a window is opened and closed in the server. So it is better if an algorithm is developed in Java may be using Genetic Algorithms. References
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