Thomas Nolte and Hans Hansson MRTC, Department of Computer Science and Electronics M¨ lardalen University a V¨ ster˚ s, SWEDEN a a Lucia Lo Bello RETISNET Lab, Department of Computer Engineering and Telecommunications University of Catania Catania, ITALY
This paper presents an overview of wireless automotive communication technologies, with the aim of identifying the strong candidates for future in-vehicle and inter-vehicle automotive applications. The paper ﬁrst gives an overview of automotive applications relying on wireless communications, with particular focus on telematics. Then, the paper identiﬁes the key networking technologies used for in-vehicle and inter-vehicle applications, comparing their properties and indicating future challenges in the area of wireless automotive communications, with a focus on realtime aspects.
inter-vehicle communications are presented and compared, pointing out real-time related aspects, in Section 3. Finally, the paper is summarised in Section 4.
Automotive telematics enables the deployment of a number of new services and applications integrating wireless communication technology into a vehicle. As a result, the vehicle acquires new capabilities and offers more services to its users. Examples of telematics services and applications are: • Navigation and trafﬁc information systems - A vehicle equipped with a telematics unit can direct a driver to a desired location, while providing real-time trafﬁc information for a given route. • Voice recognition and wireless Internet connection Drivers and their passengers can receive and send voiceactivated e-mails while on the road. • Safety systems - Collision avoidance systems, unsafe driving proﬁling, intelligent airbag deployment systems. Communications between the vehicle and its surroundings, e.g., other vehicles and roadside objects. Automatic airbag deployment notiﬁcation. Accident and roadside assistance. An example is given by the General Motors Advanced Automatic Crash Notiﬁcation (AACN) system available on many GM OnStar TM -equipped vehicles. • Security systems - Vehicle antitheft and stolen vehicle tracking services. Tracking and remote door unlocking is provided by OnStar TM -equipped vehicles. • Diagnostics and maintenance services - Remote diagnostics and/or maintenance systems, vehicle and driver monitoring.
Nowadays the two areas that are getting most attention in automotive communications are protocols and technologies supporting x-by-wire applications, e.g., Flexray , and protocols and technologies for telematics and wireless applications. Automotive telematics refers to any kind of vehicle information or communication service that relies on a wireless communication link. There are several applications pushing for the adoption of wireless communications in automotive systems, both within the vehicle (in-vehicle communications) and between the vehicle and its surroundings (inter-vehicle communications). Looking at in-vehicle communications, more and more portable devices, e.g., mobile phones, portable GSM devices and laptop computers could exploit the possibility of interconnection with the vehicle. Also, several new applications will exploit the possibility of inter-vehicle communications, e.g., vehicle-to-vehicle  and vehicle-toroadside communications. This paper presents the most common wireless protocols used for in-vehicle and inter-vehicle communications in the automotive industry, and the ones that might be used in the near future. After an overview of typical telematics services and applications in Section 2, relevant wireless automotive networking technologies for in-vehicle and
3 Wireless automotive communications
In this section three Personal Area Network (PAN) standards for in-vehicle communications are presented: Bluetooth (IEEE 802.15.1) [1, 5], ZigBee (IEEE 802.15.4) [8, 5], and Ultra Wide Band (UWB/IEEE 802.15.3a)...