Architecture of a Vehicle Communication Gateway for Media Independent Handover Guido Gehlen, Erik Weiss, Sven Lukas, Carl-Herbert Rokitansky, Bernhard Walke RWTH Aachen University, Faculty 6 Communication Networks Kopernikusstr. 16, 52074 Aachen {guge, erw}@comnets.rwth-aachen.de Abstract— Communication within and from a vehicle is a key function for various vehicle applications, like telematics, logistics, and traffic control applications. This paper describes the flexible and extendable architecture of a vehicle communication gateway which acts as a central communication device embedded in the vehicle and managing the in-vehicle, inter-vehicle, and vehicle-to-infrastructure com- munication. The focus of this paper is the vehicle-to-infrastructure com- munication, since this link is continuously changing due to the mobility of the vehicle. To enable a seamless access to the infrastructure (e.g. internet) the gateway autonomously switches between to the “best” available communication system at the current time and location. The “best” available network is selected from a list of all possible networks according to a user policy. The policy considers the user preferences, operator contracts, Quality of Service (QoS) requirements of the used service, and security requirements. The architecture is defined that flexible that arbitrary commu- nication system can be aggregated either as local communication (short range) system or wide area communication system (long range). A prototypical implementation of the vehicle communi- cation gateway has been developed which uses GPRS, UMTS, and WLAN as wide area communication systems and Bluetooth, WLAN, Ethernet as local ones. The paper presents the architecture and the prototypical implementation of this gateway, which has been motivated by the European Union founded IST-MYCAREVENT 1 project. I. I NTRODUCTION Vehicle communication is important for various applica- tions, e.g. providing real time data for logistics applications, collecting floating car data, transmitting software updates, or transmitting live traffic and travel information. In addition, communication inside the car and to another cars have to be managed. The occupants of the car like to connect to the car infotainment system, e.g. in order to access the music repository to up- or download music files. Automo- tive service worker may like to connect using a wireless link the On Board Diagnostic unit of the car in order to read out fault codes or to run a detailed diagnosis. Vehicle-to vehicle communication is used among other things to enable security relevant applications. 1 Information available at http://www.mycarevent.com This work has been motivated by the IST-MYCAREVENT project. The project aims at developing an innovative system which utilizes the state-of-the-art technologies to support the mobile user and worker in this area of the After Sales Market of the Automotive Industry [1]. One of the use cases is to support the roadside assistants with advanced remote diagnosis services and interactive repair manuals, as well as to advice the drivers in case of an breakdown situation. A short introduction to the objectives of the project is given in the next section before the gateway architecture is presented. II. REQUIREMENTS FROM MYCAREVENT TO THE VEHICLE COMMUNICATION GATEWAY MobilitY and CollAboRative Work in European Vehicle Emergency NeTworks (MYCAREVENT) is an European Project of the 6th Framework Program [2]. MYCAREVENT aims at optimizing the European market for automotive services and repair. MYCAREVENT develops and imple- ments new applications and services which can be seam- lessly and securely accessed using mobile communication. MYCAREVENT provides the roadside technician and the driver with mobile communication following an ”Always Best Connected” (ABC) approach to facilitate the communication between the mobile users within a collaborative work environ- ment. OBD RA-Device (e.g. PDA) Drivers Car Roadside Assistant (RA) On Board Unit (OBU) RA Vehicle RAC VCG DB Vehicle Communication Gateway (VCG) (GPRS, UMTS, WLAN, …) Internet MYCAREVENT Backend/Portal Fixed Com. Gateway (FCG) Fig. 1. Exemplary scenario from IST-MYCAREVENT The vehicle communication gateway (VCG) is predomi- nantly a part of the road assistant (RA) vehicle infrastructure.