Time Aware Shaper added to Ethernet for in-vehicle networks

To meet automotive requirements for deterministic network behaviour, new protocols must be added onto Ethernet stacks to provide Audio/Video Bridging (AVB) and Time Sensitive Networking (TSN) These new protocols enable Ethernet to meet the demands of in-vehicle infotainment, control and safety systems.

The Excelfore TAS protocols reside in network talkers and bridges with support for TSN enhancements including IEEE 802.1Qbv and 802.1Qci. The TAS provides a circuit-switched/ Time-Division-Multiplexed (TDM) channel into the otherwise packet-based Ethernet network. This enables a specific time window to be guaranteed for the delivery of high priority traffic, for example for automotive control systems. The Excelfore TAS has demonstrated the ability to reduce the variance in measured propagation delays by more than 65% compared to Ethernet traffic without the TAS, ensuring deterministic sub-100 microsecond accuracy for time-sensitive traffic.

Shrikant Acharya, CTO at Excelfore, said: "Excelfore has consistently played a leading role in Ethernet AVB/TSN implementations. Last year we presented the first working demonstration of IEEE 802.1ASrev grand master clock redundancy. In 2016 our AVB protocol stack was the first to be certified by the Avnu Alliance for both the talker and listener functions."

The Excelfore eAVB/TSN protocol stack, including the new TAS, is available for Linux, QNX, Integrity and Android operating systems, as well as a variety of smaller RTOSs (real-time operating systems). It is already running in cameras, video displays, head units, ECUs, and network gateways that bridge to CAN, LIN, and other popular automotive busses.

Excelfore will demonstrate its in-vehicle networking solutions, including the Time Aware Shaper, at the Automotive Ethernet Congress, February 13th to 14th in Munich, Germany. Shrikant Acharya, CTO at Excelfore, will be present a session entitled ‘Implementation of a TSN Time Aware Shaper’, at 12:00 on February 14th. The presentation describes Excelfore’s implementation of a TAS on an automotive-grade Ethernet network switch IC, including presentation of data from extensive testing of differing use cases and network configurations.