A desired attribute in safety critical embedded real-time systems is a system time/event synchronization capability on which predictable communication can be established. Focusing on bus-based communication protocols in TDMA environments, we present a novel, efficient, and low-cost synchronization approach with bounded start-up time. This approach utilizes information about each node's unique message lengths to achieve synchronization. The protocol avoids start-up collisions by postponing retries after a collision. We also present a resynchronization strategy that incorporates recovering nodes into synchronization.