IEEE 1588: What’s the difference between a Boundary Clock and Transparent Clock?

IEEE 1588 2002

• Original standard
• Ordinary Clock : GrandMaster of Slave. Always a single port
• Boundary Clock
  • clock node that has two or more ports (router or switch)
  • One port as a slave clock,
  • The remaining ports are master clock for other nodes.
  • BC recovers the time of day within the slave clock and relays it as a reference to the mater clock function

1PPS

• Pulse-Per-Second
• https://www.iqdfrequencyproducts.com/media/pg/1589/1495630251/gps-do.pdf

Holdover time

• Time to maintain the accuracy during the GPS is not locked

OXCO vs. TCXO

• Oven Controlled Oscillator
  • ensure 8 microseconds of holdover from 8 to 24 hours,
• https://www.eetimes.com/document.asp?doc_id=1278627#
• TCXO(Temperature-Compensated Crystal Oscillator)