Mobile GPS Locator

'Mobile GPS Locator' is a software to localize mobile devices through mobile devices. In 2003 'Mobile GPS Locator' has been developed in cooperation with some friends and was supported by European's leading map provider Map24. The system enables users of mobile devices - such as mobile phones, PDAs or smartphones - to locate their friends and show their friends' position and current movements on their mobile device. Both, locating and to be located mobile device have to support Java's J2ME (Java 2 Micro Edition) and need the 'Mobile GPS Locator'-Software. Moreover the mobile device to be located has to be equipped with GPS (Global Positioning System).

How does it work?

The mobile device to be located is GPS capable and has access to the internet. It constantly transmits its position to a central database. In order to locate your friends, you can use two applications: The standard PC application or the application for mobile phones. Both programs show the position of the localized user on a map. To ensure the user's privacy, the 'Mobile GPS Locator' only transmits the position if the located user has allowed the querying user to do so.

Hardware Requirements

The mobile software is implemented in J2ME, which means that mobile devices need to support Java’s Connected Limited Device Configuration Specification (CLDC). Besides that, all devices need to be connected to the internet. The device that is located has to meet additional requirements:

• A constant connection to the internet: For meaningful position information, frequent updates are necessary. We recommend a near-permanent internet connection, for example GPRS. As a packet based service GPRS connections are usually charged for network traffic and not because of connection time. Since the amount of data required to transmit a position is fairly small, the resulting traffic is low.
• GPS capability: The device to be located needs access to an integrated or external GPS receiver.
• J2SE support: A J2SE program determines the exact position of the device and transfers it to the server.

Mobile Device Client

The 'Mobile GPS Locator' prototype uses mobile phones to represent mobile devices. As a Java application, it should be easy to use the software with other mobile devices such as PDAs and smartphones (as long as the devices fulfill the system requirements). At startup, the 'Mobile GPS Locator' software displays the main menu. It contains all relevant operations. You can view your position as well as the position of your friends, and you can customize the behaviour of the software in various ways.

Mobile GPS Locator: Menue	Mobile GPS Locator: Settings	Mobile GPS Locator: Map

Screenshot Desktop Client

• Autozoom
• Multiple users at a time
• Record positions and routes
• Playback of recorded routes (real-time or accelerated)
• Statistical information (e.g. altitude or speed)
• Compass rose for directions of movement
  

Extended Applications

The 'Mobile GPS Locator', can be used as a basis for further developments. For instance, internet services offering maps of Wi-Fi hotspots and coverage could be improved by providing information on their exact position. The localization of Wi-Fi hotspots could be automated. Running as a background process, a software could constantly scan the environment for hotspots. When a hotspot is located all relevant could be transmitted to the data base. GPS can also be used to improve all other Location Based Services (LBS), which are using the cell ID of the network to determine where the mobile user is. With GPS the user could be located much more precisely. As a result, better and even completely new Location Based Services could be developed.