White Rabbit is the name of a collaborative project including CERN, GSI Helmholtz Centre for Heavy Ion Research and other partners from universities and industry to develop a fully deterministic Ethernet-based network for general purpose data transfer and sub-nanosecond accuracy time transfer.
White Rabbit provides sub-nanosecond synchronization accuracy, which formerly required dedicated hard-wired timing systems, with the flexibility and modularity of real-time Ethernet networks.
[4] To achieve sub-nanosecond synchronization White Rabbit utilizes Synchronous Ethernet (SyncE) to achieve syntonization[5] and IEEE 1588 (1588) Precision Time Protocol (PTP) to communicate time and a module for precise phase difference measurement between the master reference clock and the local clock based on phase frequency detectors.
[8] About 6000 detector nodes for the LHAASO (Large High Altitude Air Shower Observatory) experiment are synchronized by a White Rabbit network.
[citation needed] At least two Cosmic Microwave Background research programs (Simons Observatory, and CMB-S4) are considering White Rabbit for the timing of their data acquisition and control systems.