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CITInet (Central Intelligent Transportation Information Network) Platform Technology White Paper

TransitMonitor Inc. January 25, 2001 Please address any comments or questions to

Abstract With the introduction of new Internet, wireless, and location-based technologies, Automatic Vehicle Location (AVL) systems are on the brink of a revolution in design and functionality. Today’s systems are proprietary and not extensible. For example, real-time data in present AVL systems is not available to location-based portals such as Vindigo or TellMe that could seamlessly tie vehicles to the locations of mobile phones. The proprietary design of AVL systems has led many companies to build their own "in house" system that cater to their specific needs. Due to limited resources the “in house” approach prevents AVL systems from being designed with future functionality or integration in mind. TransitMonitor is developing the CITInet platform, a location-based platform that includes all the necessary elements for building a sophisticated and extensible AVL system. Through a modular architecture and the use of open standard protocols, the CITInet platform is designed to readily adopt new location services or applications developed in the future. The CITInet Platform CITInet is based on a set of open-ended interfaces to facilitate integration with existing systems and development of various applications from third parties. The platform uses Enterprise Java Beans to allow portability from system to system, and module interfacing is accomplished through RMI for Java based systems or the new SOAP 1.1 interface. The latter method gives developers the freedom to use any language or development environment that supports SOAP (IBM Java, MS SOAP Toolkit for Visual Studio). Location Integration Module In order to collect location data into a spatial database, some interface must exist between the data store and the physical tracking devices in the vehicles. This module is completely technology agnostic with respect to the device that determines the location of the vehicle. Support for two-way radio, GSM, CDMA, CDPD, Mobitex, Ricochet, and a horde of other wireless protocols can be implemented. This information can then be stored on common DBMS, or location-optimized RDBMS such as Oracle with Spatial Cartridge, or Informix with ESRI DataBlade. Front-End Analysis Modules Accuracy Module The accuracy module attempts to improve vehicle location accuracy by correlating location data with road data. This improves analysis by other modules. Geocoding Module

The geocoding modules allow street addresses and zip codes to be mapped to a latitude and longitude, or vice versa. In addition to standard one-to-one data mapping, this module can provide a set of possible addresses based on the accuracy of the positioning system used. This prevents the complications that arise in systems that ignore the inherent inaccuracy of GPS and mapping systems. Voice Recognition Module The voice recognition module converts a user’s voice to text. This module can be helpful in automatically gathering a user’s address. The module can then convert the address to a lat/lon value by using the geocoding module. Data Analysis Modules Traffic Module The traffic module analyzes incoming data from fleet vehicles. Using a set of patentpending algorithms, historical data is analyzed to create high-resolution traffic predictions. Akin to radioactive tracer elements in the blood stream, this data will project clogged arteries and fast pass thrus for urban and regional transportation. External traffic data from third parties can also be integrated into this module. Routing Module The routing module can apply different routing algorithms depending on the type of data available to the system. A vehicle operator can be provided with turn-by-turn directions to his assigned destination, or a schedule for multiple stops could be optimized for efficient passenger pick up and drop off. Data from the traffic module can also be used to select the fastest route given present traffic conditions. Estimated Time of Arrival (ETA) Module Building on technology from the routing and traffic modules, the ETA module allows the accurate calculation of vehicle arrival times. Action Modules Security Module The security module allows the system to configure what data is accessible to which users. Traditional AVL systems do not provide this security layer when porting their data, but as the need to publish data to various devices and third parties grows, fine-grained features for data access will become necessary. As an example, consider a customer waiting for a delivery. That user should not be able to access the location of the vehicle unless he or she is waiting for an arrival. In order for

this feature to be securely implemented, an access system that incorporates events must be in place. Triggering Module Trigger management is one of the key features of the platform. The trigger module allows actions or events to be triggered based on certain conditions. For example, a potential fare could receive a message on his mobile phone when the vehicle picking him up is one minute away. Presentation Modules The presentation of data has become increasingly complex as more and more types of devices glut the wireless market. The proliferation of client interface standards, from HTML to J2ME, causes some difficulty in the output layer of location systems. The CITInet platform uses XML throughout to allow for easy conversion to other standards through XSL/XSLT. Mapping Module The mapping module produces real-time maps based on aggregate data (e.g. static locations, roads, mobile locations). Maps can be used for dispatcher displays or to provide low-resolution snippets for mobile devices. B2B Integration and Open Location Services Module The use of an XML-based request/response interface allows for future developments in the realm of Location Services. These services, while still in their infancy, are starting to develop open operating standards. When standards such as openLS1 are solidified, TransitMonitor will provide a complete standards-compliant platform upgrade to allow for the open publication of location data and the integration of third-party location services. Messaging Module The development of Jabber, an open-source messaging platform, has raised some interesting possibilities for a location-based message helper. This system would allow users to send messages through standard protocols (e.g. AIM, MSN, Yahoo) to mobile users. By combining location with an already ubiquitous messaging platform, a new realm of applications is possible. For example, instant messaging could be used to communicate data, such as arrival times of vehicles, to users regardless of the service or device they use. Advertising Coupled with a digital display, the advertising module can push advertisements to a vehicle based on its location and time.


Voice Any instructions or data that needs to be returned to a user, such as turn-by-turn directions for vehicle operators, can be voice synthesized for convenience or safety precautions.

WAP/WML Messaging







Informix Server

Triggering Oracle (Spatial) Server








Voice Recognition





CITInet TransitMonitor