CarRing

Automotive technology does not have a uniform automotive network, but works with different network concepts such as the CAN bus, the LIN bus, MOST or FlexRay. However, since the car of the future will not be able to get by without a uniform communication network that has a high data transfer rate and real-time capability, the Information Technology Center at Clausthal University of Technology has launched a research project called CarRing II.

CarRing II is a real-time capable network in ring topology with high data rates. CarRing II will meet the future requirements of a high-speed network.

CarRing II is characterized by data rates of 200 Mbit/s to 1 Gbit/s and offers reliable connections of sensors, actuators and control units, which are called attachments in the CarRing concept. In addition to the attachments, the CarRing concept also recognizes nodes that implement the CarRing protocol. The individual rings transmit unidirectionally, they are connected to each other via switch nodes and can each comprise up to 16 nodes. Communication between the nodes is full duplex. Up to 255 rings can be interconnected via the switch nodes.

CarRing uses inexpensive plastic fibers as the transmission medium. Data rates of 10 Gbit/s can be realized for connections of less than 100 m. CarRing uses TDMA with Register Insertion( RI) as access method and thus guarantees a maximum packet delivery time. Header and user data are encoded using 8B/10B coding, and error detection is performed using cyclic block checking(CRC).

The redundancy of the CarRing concept is achieved by a second standby node that operates as a bypass.