Whiterabbit - a novel, high precision timing system

TLDR: The WhiteRabbit timing network is a deterministic field bus, based on synchronous GBit Ethernet and the Precision Time Protocol (PTP).

Abstract: The WhiteRabbit timing network is a deterministic field bus, based on synchronous GBit Ethernet and the Precision Time Protocol (PTP). The WR protocol was designed to provide precise timing and event distribution for high end real-time systems and was therefore chosen as the timing basis for the new GSI FAIR accelerator facility. With precise phase measurement to compensate for signal propagation delay, a timing accuracy down to sub-nanosecond rangeis feasible. To achievenecessarydeterminismandrobustness (packet loss of 10 12 ), an OSI layer two Forward Error Correction and Quality of Service protocol have been introduced to the concept. Special switches wield the WR protocol,while beingtransparentto normalEthernettraffic. Switch hardware is currently under development at CERN and will be a mixed FPGA/CPU solution. Working prototype cards have been introduced at the 3rd WR Workshop at CERN in 2009, demonstrating phase measurement and PTP capabilities. The presentation will contain detail on technical concepts, current project status, as well as future areas of application will be part of the discussion.