The Taxi-on-Demand (ToD) system developed within the context of the IST project LIAISON, is a fully automated taxi booking and dispatching system, incorporating the following features:
- Automated multilingual-enabled registration/booking transaction module
- Location-based ad-hoc grouping mechanism for booking request publication and taxi driver selection
- Data/GIS capabilities over GPRS/UTMS networks
- Automated back-up voice support over TETRA
- Dynamic routing with traffic hints and POIs
- Route guidance with elevated 2D graphical interfaces
- Manual/automated emergency alert mechanism and real-time in-car surveillance
The ToD system features an intelligent scheme for automating traditional taxi dispatch functions through the establishment of peer-to-peer location-based ad-hoc grouping (LBAG) of drivers. Ad-hoc groups are created dynamically based on the drivers' locations and other critieria, while their membership is dynamically updated as drivers move in and out of pre-define geographical areas.
When a customer submits a taxi booking request, this is sent to the drivers within a particular LBAG, based on the location of the customer and other customisable criteria (e.g. customer preferences, etc.). Drivers respond affirmatively, and the LBAG mechanisms determines the most appropriate taxi for the request, based on proximity, availability and customer preferences. The customer confirms the booking upon provision of route duration and cost estimates, and receives an automated message including estimated time of taxi arrival, vehicle identification (plate numbers) and driver identification data.
From an architectural point of view, the ToD system comprises the following components:
- Location Server (LOC_S): this server hosts the positioning functionality, providing location information (e.g. A-GPS) to the other ToD subsystems
- Location-Based Services Platform (LBS_P): this platform contains maps incorporating all the relevant no-turn, direction and PoI information. It's main task is to support traffic-aware routing, navigation/route guidance, and geo-coding/reverse geo-coding data provision. It is also responsible for providing time and cost estimates for routes.
- LIAISON Mobile System (LMS): this consists of ToD mobile application (including the GUI with all the information needed by the taxi driver to bid and service booking requests, manage messages, trigger alerts, etc), a GPRS/UMTS data modem for data communications between the LMT and the dispatch centre, a TETRA terminal providing TETRA connectivity for voice communications between the driver and the dispatcher, a GPS receiver, and an in-car web camera.
- Remote Control Center (RCC) and Enterprise Information System (EIS): this is the heart of the ToD system consisting of an Operations Centre server hosting basic ToD services, and an Enterprise Information System comprising GUI clients for both "live" and "back-office" operations (booking and fleet management) of the human operators, and a Web Interface for customers accessing the ToD service online
- Data Bearers: The data communication between the RCC and the LMT is achieved through GPRS/UMTS connectivity. Data communication between the customer and the RCC/EIS is implemented via customer terminal access (HTTP) for booking order submission, registration and profile editing, and both mobile (PDA application) and fixed (web interface) access is supported. Also, SMS messaging is providing to the customer mobile terminal for informing the customer of various (e.g. taxi approaching, etc.)
- Voice Bearers: The voice communication between the taxi driver and the dispatcher is accomplished via TETRA. An automated procedure is defined for dialling special numbers (e.g. in emergency, or data communication failure situations), and 2-party and multi-party calls are supported.
The following diagrams depicts the ToD system architecture.