can be accessed from any application on the infotainment system, regardless of the device it is deployed and executed on anything from a navigation application on the HU to a Web browser on the rear-seat entertainment unit. Using WLAN, the HU can also act as a WLAN hotspot for the user’s mobile devices such as a tablet PC.
IP-based protocols are also used for communication between applications on the infotainment network. For example, they are used to transmit large amounts of data like a metadata database for the media player application or to access HTML-based information. By using such stable and well-proven mechanisms, new features can be introduced more easily.
For security reasons, the Internet traffic of applications on the infotainment system is routed via an encrypted connection through a backend system. The backend system can control, filter, and modify the traffic through firewall mechanisms or through a virus scanner, and protect the infotainment system from the rapidly evolving threats of the Internet. In order to reduce the load on the backend system, the Internet traffic of the user’s mobile devices and of some media streaming applications (e.g., IP radio) is not routed through the backend system. Further security mechanisms need to be deployed on the infotainment system to guarantee the security of these applications.
3. IP Mechanisms and Roles
To achieve the functionality described above, the devices on the system implement different IP-related mechanisms accordingly (see Fig. 1).
Figure 1: IP Architecture of a Vehicle Infotainment System
Usually, the HU is the central router for the system and has similar responsibilities to a DSL router at home. Currently, the system does not contain a MOST-based communication unit with an embedded UMTS or LTE module, which could alternatively adopt the roles of the router and the mobile device, which provides Internet access. However, the IP architecture is prepared for such an extension. Other devices on the MOST network can access